section: d4.1 civil works - general general · section: d4.1 1. this specification is to cover the...

ITB Volume – III NAGOTHANE CPP

Reliance Group Page 773 of 906

CIVIL WORKS - GENERAL GENERAL

SECTION: D4.1

1. This specification is to cover the design, preparation of general arrangement, construction as well as Fabrication drawings, supply of all labour as well as materials and construction of all civil, structural as well as architectural work on LSTK basis for the proposed power plant at Nagothane, in the state of Maharashtra.

2. Description of various items of work under this specification and nature of work in detail are given hereinafter. The complete work under this scope is referred to as CIVIL WORKS. Lists of various civil works are covered under the scope of work given in SECTION - D4.2.

3. The work to be performed under this specification consists of design, engineering, execution, supervision as well as providing all labour, materials, consumables, equipment, temporary works, temporary labour and staff colony, constructional plant, fuel supply, transportation and all incidental items not shown or specified but reasonably implied or necessary for the completion and proper functioning of the plant, all in strict accordance with the specifications, including revisions and amendments thereto as may be required during the execution of the work.

4. All materials including cement, reinforcement steel, structural steel shall be arranged by the BIDDER.

5. The scope shall also include setting up by the BIDDER a complete testing laboratory in the field to carry out all relevant tests required for the civil works for the project.

6. The work shall be carried out according to the design/drawings to be developed by the BIDDER and approved by the OWNER. For all building and structures, foundations, etc., necessary layout and details are to be developed by the BIDDER keeping in view the statutory & functional requirements of the plant and facilities and providing enough space and access for operation, use and maintenance. Certain minimum requirements are indicated in this specification for guidance purpose only. However, the BIDDER’s offer shall cover the complete requirements as per the best prevailing practices and to the complete satisfaction of the OWNER.

7. BIDDER shall inspect the site, examine and obtain all information required and satisfy himself regarding matters and things such as



CIVIL WORKS - GENERAL SECTION: D4.1

access to site, communications, transport, right of way, the type and number of equipment and facilities required for the work, availability of local labour, materials and their rates, local working conditions, weather, tidal / flood levels, subsoil conditions, natural drainage, etc. Ignorance of the site conditions shall not be accepted by the Owner as basis for any claim for compensation or extension of time. The submission of a bid by the BIDDER will be construed as evidence that such an examination was made and any later claims / disputes in regard to price quoted shall not be entertained or considered by the OWNER on account of ignorance of prevailing site conditions.

8. In case of any conflict between stipulations in various portions of the specification, most stringent stipulation would be applicable for implementation by the Bidder without any extra cost to the Owner.

9.0 GEOTECHNICAL INVESTIGATION

OWNER is carrying out a brief Geotechnical Investigation in the proposed power plant area and the Report shall be made available shortly. However this report shall be considered by the bidder for reference only.

9.1 Bidder may make his own assessment for the type of foundations

envisaged based on the report (to be made available shortly) at his own risk. In any case, the Bidder has to carryout detailed geo technical investigation after the award of contract, through some approved/reputed agency and submit geotechnical investigation report with recommendations for Owner’s review and approval. The recommendation given in approved final report becomes binding on the contractor. The Bidder is not eligible to increase his cost or demand any extension of time because the final report is in variance from preliminary report furnished by Owner.

10. SURVEY DATA

The basic site plan giving contours etc is attached with bid documents. The bidder shall be required to make the plant layout considering the contour and minimum cutting and filling. Bidder is required to do the grading for entire area by filling or cutting. Excess/surplus excavated material shall be disposed off by the Bidder as per the instructions of the Employer upto a lead of about 5 km.

11. STATUTORY REQUIREMENT

BIDDER shall comply with all the applicable statutory rules pertaining to Factory act, Fire safety rule of Tariff Advisory Committee, Water act



CIVIL WORKS - GENERAL SECTION: D4.1

of Pollution control board, Explosives act, local civil authority including building use permission etc. Provisions of Safety, health and welfare according to Factories act shall also be complied with. Statutory clearances and norms of State Pollution Control Board shall be followed. BIDDER shall obtain approval of Civil / Architectural drawings from concerned authorities before taking up the construction work.



SECTION: D4.2

CIVIL WORKS - SCOPE OF WORK

1.0 SCOPE OF WORK 1.1 The works covered in this section consists of collection of all site related data,

conducting site investigations, design, preparation of all construction drawings, supply of all materials, construction, fabrication, erection and testing where necessary, of all structures required for housing all equipment and civil works for all services required for the Power Plant defined in the specification document. The Civil works shall include those required for Installation, Commissioning, testing, operation and maintenance of the Power Plant. The Scope will cover but not limited to the following buildings / structures / systems / facilities.

1.2 Site related investigations, consisting of

a) Topography Survey b) Geotechnical Investigation

1.3 Site development works, consisting of

a) Fencing. b) Roads, drains and culverts c) Storm water drainage d) Sewage / waste water drainage

1.4 Construction enabling works b) Construction water e) Construction power

1.5 Temporary buildings 1.6 GTG & STG Building

1.7 Control & switchgear building 1.8 Heat Recovery Steam Generator

1.9 Foundation inclusive of GTG, STG, BFP etc,

1.10 Steel stack for HRSG 1.11 Transformer yard structures & foundations

1.12 Switch yard structures & trenches

1.13 D M plant building, DM water storage tank & Condensate storage tank



SECTION: D4.2

CIVIL WORKS - SCOPE OF WORK

1.14 Condenser cooling water system

1.15 Cooling water pump house, fore bay & C W pipe line 1.16 C W inlet & outlet conduits

1.17 Clarifiers, Chlorination room, clarified seawater storage tank, Filter water storage tank and pump houses 1.18 Make up water pipe line 1.19 Cooling tower

1.20 Service water over head tank 1.21 Pipe, cable rack and pipe sleepers

1.22 Guard pond

1.23 Fuel gas receiving and metering station

1.24 Deaerator , BFP building, MCC room 1.25 Air compressor room

1.26 Fuel gas control room

1.27 Gas conditioning skid It is not the intent to specify herein all the works in the scope of this contract. The scope also includes all other buildings, structures and works necessary which are not specifically mentioned here but required for construction, operation and maintenance of the power plant are deemed to be included in the scope of the Contractor. All works shall conform to the specification. The works shall conform to high standards of design, engineering and workmanship. Design and construction shall conform in every respect to all local and state regulations governing such works and to stipulations of Indian Standards unless stipulated otherwise in detail specification.



SECTION: D4.3

DOCUMENTS TO BE SUBMITTED BY BIDDER WITH EPC

BID PERTAINING TO CIVIL WORKS The following documents are to be submitted by bidder with EPC bid

1. Suggested plot plan locating all buildings, structures, facilities, roads, temporary site office, etc. with their plan dimensions. 2. Write up on proposed storm water drainage system furnishing layout of the drains, types of drains and suggested disposal system. 3. Write up on proposed sewage disposal system for the toilet in various buildings and scheme for usage / disposal of the clear water.

4. Write up on proposed treatment and disposal of effluent / waste water generated in the plant and scheme for usage / disposal of clear water. 5. A detailed write up on Condenser cooling water system along with schematic drawing showing preliminary sizing and details of Cooling towers, channels, forebay and pump house, cold and hot water conduits and the method of construction. 6. A detailed write up on make up water system for the cooling tower blowdown, covering, source of water, Intake / withdrawal arrangement, pump houses, conduits along with method of construction. 7. A report on foundation proposed for various structures, buildings and facilities based on the data furnished by OWNER and further data collected by the BIDDER. Allowable safe bearing capacity for open foundation, depth of foundation, need for pile foundations, soil improvement if any required, special precaution against aggressive soil etc shall also be covered in the report. 8. A write up on dewatering system proposed at the time of construction where deep construction such as for C.W. forebay and pump house etc. are to be executed where water table is higher.

9. General arrangements / architectural drawings for all buildings and structures showing dimensions, levels, plans, sections, elevations, materials proposed, types of framing, wall / cladding, floors, roofs, types of finishes etc.

10. Detail design criteria proposed to be adopted for each building, structures, foundations, facilities etc.

11. A write up on the sizing and constructional details of steel stack with sketch showing detail of foundation along with list of appurtenances.

12. List of software proposed to be used in various areas for analysis, design, drafting as well as project monitoring along with their sources and validation report for software.


Reliance Group 79 of 906

SECTION: D4.3

DOCUMENTS TO BE SUBMITTED BY BIDDER WITH EPC

BID PERTAINING TO CIVIL WORKS

13. List of all sub-contractors that the BIDDER proposed to employ, in case the contract is awarded to him, indicating their addresses with telephone number, experience on similar jobs, name, qualification and experience of persons who shall be employed in the job on behalf of the sub-contractor etc shall be submitted to the OWNER. Only the Sub Contractor, approved by the OWNER shall be engaged by the CONTRACTOR on the job.

14. Details of quality control laboratory with a list of testing equipment shall be furnished.

15. All deviations from bid document shall be furnished by BIDDER in the format given in the specification document. Deviation furnished elsewhere in the bid other than at the place titled “Deviations” will not be considered as deviations. 16. Any exclusions from the scope mentioned and implied in these specifications, shall be clearly mentioned by the BIDDER separately in a section titled “EXCLUSIONS”. Only the details mentioned in this section shall be considered as exclusions. All works, other than these, shall be deemed to be in the scope of this contract and shall be executed by the CONTRACTOR at no extra cost to the OWNER.



SECTION: D4.4

DOCUMENTS TO BE SUBMITTED BY CONTRACTOR

AFTER THE AWARD OF CONTRACT

1.0 The following documents are to be submitted for the approval of the OWNER, prior to commencement of fabrication & erection / construction. All drawings shall be of standard sizes (Metric system) and shall be made on AUTOCAD latest version. The list is not exhaustive but indicative only:

(a) General plant layout drawing with co-ordinates of roads, boundary wall, buildings and facilities, piping / cable corridors, pipe and cable trestles, provision of landscaping and green belt development, diversion drains, equipment lay down areas etc. (b) Drawing showing underground facilities with co-ordinates of these facilities like buried pipes, buried cables, trenches, ducts, sewer, drains, sumps, pits, culverts, foundations etc. (c) Storm water drainage study furnishing levels of various terraces arrangement and details of drains, culverts etc for storm water drainage system.

(d) Study note on disposal of sewage and other effluent from the plant to satisfy the statutory requirement.

(e) Design basis memorandum for all buildings, facilities,services and

structures.

(f) Deleted. (g) Architectural floor plans, elevations, cross sections and perspective

view in colour of all buildings. For main plant building BIDDER shall submit two different schemes along with a report elaborating the underlying philosophy of the proposed architectural concepts.

(h) Design calculations and drawings for foundations / substructure and superstructure of all buildings including pump houses and other structures. (i) Design calculations including dynamic analysis and drawings for all foundations subjected to dynamic loads like foundations for GTG, STG etc.

(j) Design calculations and drawings for all facilities and services like roads, culverts, bridges, paving, road / rail crossings, drainage pump house (if required), drains, sewers, water supply, water tank, sumps, tunnels, trenches, ducts etc.

(k) Drawings of all architectural works including finish schedule, colour scheme (both internal and external), doors and windows, flooring and false ceiling, etc.



SECTION: D4.4

DOCUMENTS TO BE SUBMITTED BY CONTRACTOR

AFTER THE AWARD OF CONTRACT

(l) Design calculations and drawings for plumbing and building

drainage. (m) Design calculations and drawings for structures and foundations

in switchyard, transformer yard, etc.

(n) Design calculations and drawings for structures pertaining to cooling water system.

(o) All other designs, details / drawings or any other submissions as

indicated else where in this specification and as required by the OWNER.

(p) Details of corrosion protection measures for all structures. (q) Total quantity of concrete (grade wise), reinforcement steel

(diameter wise) and structural steel (section wise) in all construction drawings.

(r) All design and drawings for the Cooling towers. (s) All design and drawings for steel stack.

(t) All design calculations and drawings for HRSG Foundations.

(u) Design calculations for important joint / connections for structural steel works.

(v) Construction and erection procedure for all major structures with specific reference to main plant building, GTG/STG foundation and other machine foundations. (w) Write up on various statutory requirements and their compliance

for various buildings and facilities. (x) Copies of all reports on investigation and studies carried out by

the CONTRACTOR as per the scope.



SECTION: D4.5

DESCRIPTION OF BUILDING, STRUCTURES AND FACILITIES

1.0 DESCRIPTION OF BUILDING, STRUCTURES AND FACILITIES

1.1 Following structures / buildings / areas / facilities/services are to be included in the contract. The description against each building / system is indicative only and not exhaustive. Although almost all the systems are covered here but any other system (Civil, Structural and Architectural) required for successful completion of the project shall form a part of this contract and shall deemed to be included in the scope of works.

2.0 SITE RELATED INVESTIGATION

2.1 Topography Surveying

2.1.1 All Bench Mark (BM) levels of the survey shall be established with reference to the nearest GTS benchmark available. Precision levelling shall be carried out for establishing the BM at site by carrying levels from GTS BM adopting double circuit levelling. Precision theodolites used shall be of one-second accuracy.

2.1.2 All boundary lines shall be located with their distances, included angle and bearings and boundary pillars constructed. Number of pillars shall be adequate to mark the boundary limits without any dispute. A closed traverse survey shall be carried out with theodolite to form the framework for the detailed survey work. 2.1.3 Two-reference line, North-South line and East-West line at right angles to each other shall be established with grid pillars constructed at 100 metres c/c in both directions in such a way that these pillars will not be disturbed during construction. Coordinates shall be painted on these grid pillars. Pillars shall also be painted using synthetic enamel paint for easy identification. Benchmark pillars shall be provided atleast at 6 locations. These pillars shall be properly protected to prevent their disturbance during construction activities. BM shall be distinguished from grid pillars with different type of painting. 2.1.4 Spot levels shall be taken in a grid of five meters (5 m) and contours shall

be established at an interval of 500 mm. All Contour levels shall be with respect to MSL.

2.1.5 Contractor shall furnish one soft copy in a floppy along with six (6) copies of all survey drawings to the Owner for his reference.

2.2 Geotechnical Investigations

2.2.1 Detailed geotechnical investigation shall be carried out by the Contractor on award of work. Based on the plot plan developed, the Contractor shall



SECTION: D4.5

DESCRIPTION OF BUILDING, STRUCTURES AND

FACILITIES

prepare field and laboratory testing scheme and obtain the approval of Owner prior to commencing the investigation. In the power block boreholes shall be provided and spread judiciously to cover all major structures as well as equipment foundations. Generally, a grid of 50 metres c/c both ways is recommended from Stack to end of Switchyard. In the other areas it shall be ensured that the boreholes are provided near all major structures. If the final geotechnical investigation report found variance with the results of the preliminary investigation, the contractor is not eligible for any extra claim or time.

2.2.2 Following field tests shall be conducted:

Bore Holes and standard penetration tests

Static Plate load tests

Cyclic Plate load test

Permeability tests

Density and moisture content tests

Vane Shear tests

Static Cone and dynamic cone Penetration tests

Soil resistivity tests.

Pressure meter tests

Percolation test

2.2.3 Boreholes shall be located to cover the entire area. All boreholes shall be sunk up to a depth of 25.0 m or 5.0 m continuous into hard rock whichever is earlier.

2.2.4 Standard penetration tests (SPT) and collection of undisturbed soil

samples (UDS) shall be carried out alternatively at 1.0 m intervals and at significant change of strata. The interval shall be increased to 1.5 m below 5 m depth of boring. UDS shall be replaced by SPT in cohesion less strata. Even in highly weathered / disintegrated rock, where core recovery is poor, SPT shall be conducted. The first SPT in any borehole shall be conducted at 1m depth.

2.2.5 In rock strata, core recovery and Rock Quality Designation (RQD) shall be noted carefully for each run, immediately after cores are taken out of barrel.

2.2.6 During boring, the level at which ground water is struck shall be carefully noted. Ground water samples shall be collected for chemical analysis. Water samples shall be collected before the addition of water or drilling mud to the hole. 2.2.7 Following laboratory tests shall be conducted: (Preferably on Undisturbed soil samples and if UDS is not possible, on remoulded soil samples.)

(a) Grain size analysis



SECTION: D4.5


FACILITIES

(i) Hydrometer analysis

(ii) Sieve analysis (b) Specific Gravity (c) Chemical Analysis of soil and ground water including

Sulphates, Chlorides, pH value, etc.

(d) Chemical Analysis of 2:1, Water:Soil extract of the samples giving SO3 content.

(e) Consistency Index : Liquid Limit, Plastic Limit, Plasticity Index, Shrinkage Limit and Shrinkage ratio.

(f) Consolidation test giving all relevant parameters.

(g) Swelling pressure and free swell index for expansive soils.

(h) Unconfined Compressive Strength on soil samples

(i) Direct Shear Test

(j) Triaxial Compressive Strength Tests:

(i) Unconsolidated Undrained Test (ii) Consolidated Undrained Test (iii) Consolidated Drained Test

(k) Moisture-density relations for Standard Proctor and Modified Proctor tests.

(l) Crushing Strength, specific gravity, unit weight, water absorption test on Nx size rock specimens.

(m) Permeability test 2.2.8 The Geotechnical investigation report shall necessarily include, but not

be limited to the following information.

(a) Recommended types of foundation.

(b) Allowable safe bearing capacities and settlement values in different strata for shallow foundations indicating relevant design criteria adopted, method of analysis adopted etc.

(c) If pile foundations is envisaged, type of pile recommended with reasons for the same, length, diameter, allowable capacity (vertical, lateral and pullout) of individual and groups of piles,



SECTION: D4.5


negative skin friction if any and magnitude of estimated negative skin friction.

(d) Recommendations for values for modulus of subgrade reaction

for foundation design. (e) Type of cement to be used for concrete substructures and in

stone / brick masonry foundations with reference to the chemical nature of subsoil and ground water.

(f) Recommendations regarding excavations (shallow & deep), embankment, safe side slopes for excavation and embankment, dewatering, site drainage, etc. (g) Recommended soil properties such as density, specific gravity, cohesion, angle of internal friction etc. for design. (h) Precautions to be taken for design of lightly loaded structures when expansive soil is encountered with respect to swelling pressure and free swell index values obtained. (i) Recommendation for soil improvement if required, to be

indicated in the report.

2.3 Site Development Work & Site Grading

2.3.1 The CONTRACTOR has to carryout detailed bathometric survey to ascertain the maximum flood level. The bathometric survey has to be submitted to owner for approval. After obtaining the formal approval, the required grade level of the plant area shall be graded by the Contractor considering the contours, minimum cutting and filling. In no case the grade level shall not be less that 1000mm above maximum flood level of 50 years.

3.0 Fencing Minimum 3 m high fencing above the toe wall shall be provided around the entire switch yard, transformer yard, auxiliary transformer yard, fuel tank farm, stores etc wherever fencing is necessary due to security / safety / statutory requirements. Fencing shall comprise of 2.4 m high PVC coated galvanised chain link fence of minimum 8 guage (including PVC coating) with mesh size 75 mm and galvanised barbed wire on inclined member to a height of 600 mm above the chain link fencing. 3 Lines of 12-gauge high tensile spring steel wire shall be provided for the entire length of fencing. Also 50 mm X 6 mm galvanised MS flats shall be provided at every fifth post sandwiching the fencing with post using GI nuts and bolts. Top of toe wall shall be 200 mm above formation level. Toe wall shall be generally of RCC construction and shall extend 150 mm



SECTION: D4.5


below the formation level and the fencing mesh shall be embedded inside toe wall by minimum 75 mm. Fencing post shall be fabricated out of galvanised MS angle section of minimum 75x75x6 mm size and shall be spaced at a maximum spacing of 2.5 m with struts made up of galvanised MS angle at every fifth fencing post in addition to those at bends. Expansion joint shall be provided at every 60 m. Steel entry gates shall be provided for all fenced areas. Gates shall be formed out of tubular section conforming to IS:1161. Removable type of fencing shall be provided at suitable location to permit entry and exit of equipment.

4.0 ROADS, DRAINS AND CULVERTS:

4.1 Access roads and vehicular parking areas shall be of flexible pavement type with water bound macadam base and bituminous topping on prepared surface.

4.2 The main access road from the existing asphalt road to the plant boundary shall be four lanes with a refuge of about 2 m wide in between double lane ‘up’ and ‘down’ roads. The road shall be designed to cater to the load and needs of construction and maintenance of heavy trucks carrying machinery and heavy cranes.

4.3 All other plant internal roads providing access to buildings / structures / systems for vehicular movement shall be 7.5 m wide. All other minor roads shall be 4 m wide. 1500 mm / 750 mm wide (1500mm for 7.5 M wide Road / 750mm for 4 M wide Road) road shoulder shall be provided on both side of all two lane roads paved with interlocking concrete paving blocks of approved shape/design and colour.

4.4 Road construction shall be as per IRC standards. However the minimum

requirement for the roads shall be; 200 mm thick (consolidated thickness) sub base course laid in two layers of 100 mm each and 150 mm thick (consolidated thickness) water bound macadam base course laid in two layers of 75 mm each and topped with 50 mm thick semi-dense bituminous carpet. The minimum thickness of black topping shall be 50 mm. Bituminous topping of all plant roads shall be taken up after all the major construction activities are completed.

4.4 On either side of the roads covered drains shall be provided. Minimum

clear width of the drain shall be 600 mm. The drains shall be designed and built using RCC. Drainage lines and other under ground services shall be located at least 1 m clear from the edge of the road. All service and utility lines crossing the roads shall be taken up through NP3 class RCC pipe designed for impact loading. All culverts carrying storm water shall be cast-in-place RCC box culverts.

5.0 STORM WATER DRAINAGE: 5.1 Run off coefficient for paved and unpaved areas shall be taken as 0.9

and 0.6 respectively.



SECTION: D4.5


FACILITIES

5.2 Storm water drainage system shall be designed in two parts.

(a) Main drains (b) Auxiliary drains

Main drains shall be designed as a network covering total plant area and shall ultimately be led to nearest water body. Auxiliary / branch drains shall cover individual graded terraces to collect discharge from plant buildings and shall connect to main drain at suitable locations.

5.3 Drainage for plant effluent and storm water shall be carried by gravity. The drains shall generally be open type and constructed of RCC. RCC box culverts shall carry drainage under roads.

5.4 At places where covered drainage system is required, channels with

removable cover shall be preferred to piping system, as piped system tends to get blocked. Underground storm water piping shall be restricted strictly to areas where surface drains are not desirable or practicable from functional point of view.

5.5 Drainage shall be provided where necessary to prevent ponding and

ground erosion and to carry surface water away from building, structures and other works including roads, building or equipment foundations.

5.6 The storm water drainage for the contaminated area such as fuel oil areas and oil skids etc. shall be designed separately and the discharge shall be led separately for treatment and disposal through oil water separator.

6.0 Sewage / Waste Water Drainage 6.1 For plant area sanitary sewage disposal, separate septic tanks shall be

provided at suitable locations for each building complex. Effluent from the septic tank shall be connected to a common combined sewage treatment plant. The treated effluent shall conform to the requirement of Pollution Control Board.

6.2 Waste water generated from the plant and canteen wastewater shall be treated in a full-scale effluent treatment system. The treated effluent shall be used for watering the trees and maintenance of green belt area. Provision shall also be made for collection and disposal of solid waste. Generally be HDPE pipes of superior quality above ground level and CI pipes below ground level shall be used to carry sewage / waste water where pipes are laid in original ground. The pipes shall be encased in concrete at road crossings. Manholes shall be at junctions and change of direction. In straight stretches manhole shall be provided at a maximum spacing of 30 m. The excess water from this collecting tank



SECTION: D4.5


FACILITIES

shall be led to nearest plan peripheral drain. Plant effluent water shall not be mixed with treated sewage / sanitary water.

6.3 Unless specifically cleared by the Owner, no sewer pipes shall be allowed

to come close to water supply pipe lines 6.4 The bedding shall be of granular material well compacted and the pipes

rest evenly at the correct level. 6.5 Jointing of laid pipes shall be so planned as to avoid completely any

movement or strain to the joints already made. If any joint is suspected to be damaged it shall be opened out and re done.

6.6 All joints between pipes, pipes and fittings and manholes shall be gas- tight when above ground and water tight when underground.

6.7 Manhole shall be provided with standard C.I covers. The cover shall be

close fittings so as to prevent gasses from coming out. Suitable heavy- duty covers shall be used where necessary.

7.0 CONSTRUCTION ENABLING WORKS

7.1 Construction water: 7.1.1 The OWNER shall provide water at one point with in the plant boundary

for a limited purpose such as for construction. The CONTRACTOR may avail this facility. Necessary charges for drawing the water shall be borne by the CONTRACTOR.

7.1.2 Alternatively Contractor has to reconnoitre the area and conduct necessary studies to identify the source of water for construction purposes. Necessary permission to tap these sources shall be obtained by the Contractor from competent authorities. 7.1.3 Cost of all connected works such as but not limited to Intake structure /

bore wells, pumps, pipeline, ground water reservoir etc are to be borne by the Contractor.

7.2 Construction power 7.2.1 Construction power will be made available at a single point, metered and

supplied on chargeable base by the owner. Further extension of power line to the various locations required shall be executed by CONTRACTOR at his cost. CONTRACTOR has to make provision of D.G sets as standby power source. This is especially in the case of structure involving deep dewatering as well as where uninterrupted concreting has



SECTION: D4.5


to be resorted to. The bidder along with his bid shall indicate his average and peak power demand.

8.0 TEMPORARY SITE BUILDINGS 8.1 The Contractor shall provide for at his cost the following building facilities

for proper execution and quality control of the job, while meeting the provision stipulated by Factory Rules regarding staff welfare facilities. All these building shall have brick cladding, steel / AC sheet roofing over steel roof truss with cement concrete flooring and false ceiling with air conditioning as required.

8.2 Site office

8.2.1 The site office shall make a provision of about 300 sqm of office area with A/C and false ceiling for the use of Owner / Owner’s representative in addition to the Contractor’s requirement. Additionally an A/C Conference room to accommodate about 25 people shall also be provided in the site office complex for the Owner’s use. In addition to these, basic facilities like toilet for gents and ladies, potable water tanks, soak pit and septic tank for sewage disposal shall also be provided. Covered parking area for parking 10 cars shall also be provided for Owner’s use.

8.3 Stores

8.3.1 A covered store shall be provided with brick cladding and A.C./G.I./colour coated sheeting to store at least one month requirement of cement. Cement in bags shall be stored on a raised floor well away from outer walls and insulated from the floor to avoid moisture. Not more than 15 bags shall be stacked in any tier. Each consignment of cement shall be stored separately and consumed in its order of receipt.

8.3.2 Covered storage area may also be provided to store other construction material which will be affected on exposure to wind, sun and rain. 8.3.3 Reinforcement shall be stacked on top of timber sleepers to avoid contact

with ground / water.

8.3.4 Paved or unpaved storage yard shall be provided with in the stores complex for storage of other material.

8.3.5 Proper fencing and security arrangement shall be provided for the stores

complex.

8.4 Temporary workshop and Garage



SECTION: D4.5


8.4.1 The Contractor shall provide for a temporary workshop and garage to attend to routine maintenance and repair of the construction equipment as well as the fleet of vehicles used for construction activities.

8.5 Fabrication yard 8.5.1 Depending on the extent of fabrication envisaged at site, the Contractor

shall establish a full fledged structural fabrication yard with adequate handling facility during and after the fabrication. A fully equipped testing laboratory providing radiography, ultrasonic, dye penetration, magnetic particle test facilities shall be ensured adjacent to the fabrication yard to enforce strict quality control. Portion of the yard shall have covered shed with HOT / EOT cranes so that fabrication work can proceed even during inclement weather.

8.6 Quality Control Laboratory 8.6.1 A fully equipped quality control laboratory shall be established at site with

qualified personnel to conduct acceptance test on all construction material, weldments, concrete cubes etc. This laboratory shall be housed in a covered building with A/C facility as required by the testing facility. All testing equipment shall be procured by the Contractor and they shall be periodically calibrated to the satisfaction of the Owner.

8.7 Fuel storage area

8.7.1 Contractor shall obtain necessary permission from competent authorities and establish and operate a POL outlet with proper storage, dispensing and adequate fire fighting facility.

8.8 Staff welfare facility

CONTRACTOR shall provide adequate facility for his staff as necessary statutory requirements. Necessary approach roads to the construction facility complex and internal roads within the complex as well as proper drainage of the area shall be the responsibility of CONTRACTOR.

8.9 Labour colony CONTRACTOR shall identify sufficient area outside the property boundary to locate his staff and labour colony no area inside the plant boundary shall be used to house the labour colony. Construction and maintenance of the staff and labour colony to satisfy all statutory requirements is the sole responsibility of CONTRACTOR.

9.0 Gas Turbine And Steam Turbine Generator Building

9.1 GT and ST shall be housed in one single Building. Generator part of GTG portion of building alone can be without crane approach. However layout



SECTION: D4.5


of GT shall be such that the part of GT to be handled by crane shall be approachable from STG building crane.

9.2 Turbine building framing shall be of structural steel with moment connected framing in the transverse direction and bracing in the longitudinal direction.

9.3 Service and maintenance bays shall not have any intermediate floors, however a 1500 mm wide observation gallery with handrails shall be given at the operating floor level to observe the TG erection operation. 9.4 Crane capacity and crane rail level shall be fixed based on the equipment to be lifted and the method of lifting various heavy parts. At crane girder top flange level a crane walkway shall be provided in line with Factory rules. Access shall be provided to crane walkway through a cage ladder from operating floor at two ends. Bottom level of roof framing shall be decided by the crane clearance requirement duly taking into account clearance required for mounting lighting fixtures. All other requirements of the crane shall be as outlined in the Mechanical section of this document.

9.5 Side cladding shall be of brick wall / solid concrete block wall 9.6 Windows shall be sliding windows in anodised aluminium framework using

6 mm thick glass in general. However in areas where cladding is of sheeting, fixed glazing in anodised aluminium framework and in accessible areas sliding windows in anodised aluminium framework using 6 mm thick glass shall be provided.

9.7 All the doors on external walls shall be of double plate flush steel doors. For equipment entry into the service bay specially designed steel sliding / cum folding / rolling shutters shall be provided with appropriate operating mechanism. Provision shall be made for the easy removal of the condenser tubes by providing a rolling shutter/space as required.

9.8 Staircases shall be protected on all sides with fireproof enclosure as per TAC regulations. All the doors leading to the inside the powerhouse from staircase shall be automatically closing type, fireproof doors satisfying TAC regulations.

9.9 Cage ladders shall be provided for access to Turbine building roof. 9.10 Medium class galvanised MS pipe of min 150 dia conforming to IS: 1239 /

IS 3589 shall be provided to drain off the rainwater from roof. They shall be suitably hidden from the facade. The roof drainage shall be designed as per IS: 1742.

9.11 The operating floor shall be RCC floor over steel framing, constructed over galvanised M.S. toughed metal sheet of approved profile, Minimum



SECTION: D4.5


150 mm thick RCC floor shall be provided over steel floor beams with an additional 50 mm floor finish which shall be applied later. The RCC floors shall be provided with proper drainage. Catch pit with CI grills shall be provided near the internal column in a regular pattern and the floor shall be sloped towards the catch pit by varying the thickness of the bedding concrete for the floor finish. Catch pits shall be at the same co-ordinate for all floor levels. 150 NB galvanised MS pipes conforming to IS: 1239 shall be provided to carry the drainage down. The pipes shall be clamped on to the intermediate column. Sumps shall be provided in ground floor to receive the water. Proper drainage arrangement shall be provided in the ground floor by means of RCC gravity channels with MS grills on top. The drainage shall be led to sumps from where the water shall be pumped to plant drainage arrangement.

9.12 Around equipment liable to frequent drainage, concrete kerb shall be provided to isolate the area and water shall be led through sump and channels to the floor drainage system. Oil water separator should be provided as required to isolate oil from the drainage water where the water is mixed with oil.

9.13 The designed live load shall be painted on all the floors prominently showing the extent of the area where such loading is permitted.

9.14 Wherever openings are provided in the floor for handling of equipment using EOT cranes, such openings shall be covered with gratings provided over removable steel beams.

Expansion joint shall be provided in the building to satisfy the requirements of IS: 800 and IS: 3414

9.15 Foundations for major equipment like gas turbine and steam turbine generator and boiler feed pump shall be mounted on properly designed vibration isolator system. However these foundations shall be isolated from the building framework.

10.0 Control and Switch gear Building 10.1 The control and Switchgear room building shall be Ground + three storied

RCC frame building with RCC floor. The building shall have passenger lift of 13 person capacity. Covered parking area for parking 10 cars, 50 two wheelers, 100 bicycles shall also be provided

10.2 Ground floor shall houses cable distribution room and also space for cable duct, battery and battery charger room, entrance foyer, entrance portico to accommodate 3 big cars, Reception hall, assembly hall to accommodate 150 persons. Separate toilet block for ladies and gents shall be provided. The building has to be provided with an elevator approachable to all the four floors.



SECTION: D4.5


10.3 The first floor shall house switchgear room, Office room with attached toilet.

10.4 The second floor shall house the main control room, computer room, electronic cubicle room, PLCC room, relay testing laboratory, I & C testing laboratory, pantry, copier. Office space for staff of performance and environment, offices of maintenance engineers of electrical, mechanical and I&C departments, separate Gents and ladies toilet cum wash rooms and space for pantry, copier and drawing storage, locker room, engineering station room, staff change room with bath & toilet. Separate toilet block for ladies and gents shall be provided

10.5 The third floor shall house four rooms with attached toilets, six additional rooms, additionally space shall be planned for the conference room to accommodate 50 persons, documentation room, storage room, office space to accommodate 40 persons, pantry, lunch room. Separate toilet block for ladies and gents shall be provided

10.6 The terrace shall house Air handling equipments, common ventilation chiller room, etc. Pleasing architectural shall be provided for the building. Each floor shall have independent AHU’s. 10.7 If not possible to accommodate the same in the Control room building, a separate building shall be provided nearer to Control room building with the same technical requirements mentioned for Control room. CONTRACTOR shall plan the space requirements as per the requirement of the Owner.

10.8 All floors shall be of in-situ RCC slab provided over RCC beams. Minimum thickness of structural concrete shall be of 150 mm with 50 mm floor finish. Roofing shall consist of in-situ RCC slab of minimum 150 mm thickness laid to a slope of 1 in 100.

10.9 Cladding shall be of brick wall supported on plinth beams. Walls in front of transformers shall be of adequate thickness and height to satisfy “fire rating” as per TAC regulations. 10.10 Most of the areas except for the area in ground floor shall be air- conditioned. Hence clear headroom below beams shall be designed to run A/C duct above false ceiling. Level of false ceiling may be 3000 mm in all the air-conditioned areas including control room, computer and electronic cubicle, etc. All air-conditioned areas shall be provided with false ceiling. False ceiling at the conference room, control room and computer room shall be of colour coated aluminium ceiling system and in other areas false ceiling may be of gypsum boards. 10.11 An auxiliary transformer yard with fencing and gate shall be provided adjoining to the building. Side cladding shall be of brick wall with wall in



SECTION: D4.5


FACILITIES

front of transformer yard made sufficiently thick to satisfy fire rating as per TAC regulations.

10.12 Staircase area shall be protected from fire safety angle as per TAC regulations. Main door to switch gear room shall be steel sliding door having adequate area to admit switchgear. There shall be minimum two doors to the switchgear room, of flush welded steel type. Control room should have one swing type aluminium glazed double panel door and one single panel door. Windows shall be aluminium glazed for switchgear room with wired glass. For control room if window is provided the same shall be of hinged type openable with 6 mm thick sheet float glass.

10.13 Roof shall be given a slope of minimum 1 in 100 towards the side opposite to transformer yard. Roof shall be given elastomeric water proofing treatment with foam concrete insulation layer. Adequate number of rainwater down take pipe shall be provided using UPVC pipe class3 conforming to IS: 4985. Garland drain as well as plinth protection of minimum 1000 mm wide shall be given around the building. 10.14 Transformer yard shall be provided with 3 m high chain link fencing with gates. In case more than one transformer is being provided, firewall shall be given to separate the transformers. Oil soak pit shall be provided below the transformer. Burnt oil pit shall be provided connecting the soak pits with RCC pipes. The transformer area shall be provided with paving using hard stone aggregates. 10.15 Partition between control room and adjoining rooms shall be of glazed aluminium partition with 300 mm high brick wall at bottom for toe protection. All the doors shall be single leaf glazed aluminium doors for all cabins. For movements of panels suitably sized double leaf aluminium glazed doors shall be provided. In other area cladding shall be of brick wall. UPS room shall be provided with brick cladding all-round to reduce sound nuisance. Battery room shall be provided with PVC doors in PVC framing.

10.16 Toilets shall be provided at the switchgear room level and control room level. Toilet floors shall be sunk and shaft shall be provided to route the soil pipe. Sunken floor shall be provided with damp proofing treatment. All openings in floor for switchgear and other panels shall be sealed with fireproof material after cables are connected.

10.17 False flooring shall be provided in the control room, electronic cubicle room and the computer room. The floor slab in these areas shall be sunk for a minimum depth of 1200 mm and false floor as specified in section D 4.6f shall be provided.

10.18 The external wall surfaces shall be provided with 20 mm thick plaster in two layers, the second layer of 6 mm shall be mixed with W.P. compound. Internal plastering shall of 12 mm thick. Ceiling in all areas shall be given ceiling plaster 6 mm thick. Main entrance shall be aluminium glazed double



SECTION: D4.5


leaf swing door of adequate size with fixed sheet glass glazing in anodised aluminium framework on either side. Separate entry with rolling shutter shall be planned for panel movement with a hatch and lifting beam on the upper floors.

11.0 Heat Recovery Steam Generator (HRSG) Area Paving

11.1 Entire HRSG area from the Gas turbine building up to the end of stack shall be provided with heavy duty RCC paving over 230 mm thick rubble soling. Minimum thickness of RCC paving shall be 150 mm with double layer reinforcement. A 50 mm thick PCC layer shall be provided in between the rubble soling and the RCC paving.

11.2 Paving shall be carefully planned such that maintenance access roads of minimum 6 m wide to all major equipment are available. This area shall be designed for heavy loads similar to design of roads. Such roadways shall be clearly identified with kerbs / painting. All drain / trench covers in these areas shall be designed to withstand truck loading.

11.3 The drainage of the entire HRSG area shall be properly planned. Network of RCC drains with RCC cover with slotted holes or MS galvanised grills shall be provided covering the entire area which lead the storm as well as process leakage water to the peripheral drains, which in turn will lead to plant drainage system. Where open drains are not permitted under ground pipes may be provided in which case at all junctions and ends proper manholes shall be provided to permit periodic cleaning of the pipes.

11.4 All structural steel column in the area shall be provided with encasing to a height of minimum 200 mm above paving level and in addition the bases also need encasing if base plate are below paving level. The maximum paved level in HRSG area shall be kept a minimum 200 mm below the finished ground floor level in Turbine building area.

11.5 Foundations for HRSG structures shall be designed duly considering the loads furnished by the boiler manufacturer in addition to wind and seismic loads applicable to site.

11.6 Type of foundation ie isolated, strip, raft, pile shall be decided based on the loading arrangement, load intensity, soil strata. Foundations shall be designed according to relevant IS codes.

11.7 Foundations inclusive of GTG, STG,BFP etc.

11.8 All machine foundations shall be designed as per the criteria furnished by the equipment manufacturer and conform to provisions of relevant IS Codes. Major equipment foundations such as TG, GT, BFP etc shall be



SECTION: D4.5


isolated from the adjacent structures. Grade of concrete shall be as per specification.

12.0 Steel Stack for HRSG

12.1 The parameters for the stack shall be designed based on the property of the gas burnt, quantity of gas generated and composition of the flue gas. The chimney shall be of mild steel with stainless steel liner inside. Individual chimney may be provided for HRSG . The height and exit diameter of the chimney are as stipulated in the mechanical section of the specification document.

12.2 Chimney shall be provided with all appurtenances such as platform, cage ladder, aviation warning lights, lightening protection system etc 12.3 The design and construction of main stack shall conform in every aspect to boiler and factory inspector’s regulation, civil aviation authority regulations and all other local and state regulations. Necessary corrosion allowances shall be considered while arriving at the shell thickness. The basic dimension of the stack such as exit diameter of the flue, height of the flue, need of liner etc., shall be decided based on the temperature, quality and quantity of flue gas, draft requirement, pollution control regulation etc., which are covered under mechanical section of this specification. 13.0 Transformer Yard Structures and Foundations 13.1 Generator transformer, Station transformer unit auxiliary transformer and

service transformer are located as per requirement close to the respective building. Transformers shall be founded on RCC foundations with rails on the top and oil soak pits filled with hard stone aggregate. Burnt oil pits are provided to collect leaked oil from the soak pit through RCC, pipes laid to slope. RCC blast wall / RCC frame with brick wall of adequate thickness and height to satisfy TAC regulations shall be provided in between transformers and between main transformer and turbine building as Fire barrier wall.

13.2 RCC foundations shall be provided with rail to transport transformers out of transformer yard during maintenance. Entire area shall be surrounded with 3 m high chain link fencing with gates. Where rails cross the fencing, fencing shall be made of removable type to facilitate transport of transformer. Floors shall be paved with plain cement concrete and shall be sloped towards peripheral drains, which shall lead to a sump from which the drainage is led through an oil water separator. The clear water shall be led to plant drainage / guard pond. 14.0 Switchyard structures and Trenches



SECTION: D4.5


14.1 Extent of the Switchyard will depend on the layout of the switchyard, which has been outlined in the Electrical section of this document. 14.2 All steel structure for the Switch yard shall be hot double dip galvanised structure with welded / bolted connections at shop and bolted connection at site. All bolts and nuts shall also be galvanised. Minimum zinc consumption shall be 900 gms per square meters of exposed surface. Design criteria of Switchyard structure are furnished else where in the specification. 14.3 Major steel structures are towers, beams, lighting masts etc. They are all of latticed construction using angle sections. In addition supporting structure for equipment, such as isolator, lightning arrestors, etc shall also be provided. These structures may be of tubular section or latticed as the case may be. Towers, beams etc shall be trial assembled at shop, keeping in view the actual site condition, prior to dispatch to erection site so that they can be conveniently pre-assembled before erection or conveniently assembled during erection.

14.4 Lighting masts shall be provided with cage ladder. Where platforms are provided on lighting masts for mounting of lighting fixtures, they shall have protection handrails formed of galvanised section. Grating used for platforms shall be galvanised.

14.5 Foundations may be open foundation or on piles based on soil / conditions.

14.5 Trenches shall all be of RCC construction. Trench walls shall be designed to withstand a surcharge load of 1500 kg / sq.m. Trench wall shall project 150 mm above the paved / graded level to prevent ingress of storm / rain water. All trench, floors shall be given a slope of minimum 1 in 750 and the slope shall lead to a sump, where pump can be installed for drainage. Cover for cable trenches shall be a per specification.

14.6 The complete area within the fencing for switch yard/transformer yard shall be provided with a mild slope towards peripheral RCC drains, which in turn will be connected to the plant drainage system. Entire switchyard area shall be provided with 75 mm thick paving using 20 to 40 mm size stone aggregate on top and 75 mm paving of 20 mm stone aggregate below. Before laying the paving, the ground surface shall be treated with anti weed chemicals as per manufacturer recommendations. 14.7 Fencing around switch yard area shall comprise of PVC coated G-1

chain link fencing of minimum 8G (including PVC coating) of mesh size 75 mm and of height 2400 mm above toe wall with 600 mm high galvanised anti-climbing device with barbed wire (8 rows) such that total fence height of 3 m above toe wall is achieved. Other details of fencing such as anti-climbing device, fencing, toe wall etc shall be as explained earlier.



SECTION: D4.5


15.0 D.M PLANT BUILDING INCLUDING NEUTRALISING PIT AND LABORATORY DM Plant Equipment area shall be of structural steel construction with colour coated metal sheeting as roof. Side cladding shall be colour coated galvanised sheeting over 3000mm high Brick wall. Dimension and height of the building / structures shall be decided based on equipment layout and height of the vessels accommodated inside.

15.1 Control room and laboratory shall be provided in an RCC framed building with brick cladding. Cable vault shall be provided below the Control room and switchgear room. Control room and laboratory shall be air-conditioned. False ceiling with colour coated aluminium-ceiling system shall be provided in this area. Under deck insulation shall be provided in the A/C area. Staircase in the control room complex shall be extended to the roof also. Flooring in control room shall have 2 mm thick PVC topping. Toilet along with the washrooms shall be provided in the ground floor. In case a transformer yard is provided the wall in front shall be designed to satisfy fire rating as per TAC. Roof shall be given elastomeric water proofing treatment as per specification. The external wall surfaces shall be provided with 20 mm thick plaster in two layers, the second layer of 6 mm shall be mixed with W.P compound. Internal plastering shall of 12 mm thick. Ceiling in areas where false ceiling is not provided shall be given ceiling plaster 6 mm thick. External finish shall be Granular finish (Vineratex) of 2mm thick over plain-faced cement plaster. 15.2 Floor where acid / alkali spillage are expected shall be isolated with RCC kerb and the flooring inside shall be of acid / alkali resistant brick. The drains carrying acid / alkali mixed discharge shall be provided with AR brick lining. Acid / alkali unloading and storage area outside the building shall also be provided with kerb with a sump inside. This area shall also be provided with AR brick lining. 15.3 Neutralising pit shall be in 2 compartments and designed as a water

retaining structure with external damp proofing. Floor and walls of the pit shall be given A.R brick lining. Ceiling as well as floor supporting pumps, pumping the clear water from neutralising pit shall be given epoxy lining. Capacity of the pit shall be as specified in Mechanical Section of the document.

15.4 DM water storage tank outside the DM plant, condensate storage tank near HRSG shall be supported on sand pad with ring wall. 15.5 Walls inside the DM plant area shall be provided with chlorinated rubber

based painting.

15.6 The chemical laboratory shall be located on top of MCC room of WT Building. Filtered water storage tanks shall be located on top of Chemical laboratory.



SECTION: D4.5


15.7 All doors and windows in the DM plant area shall be of aluminium glazed type. Windows shall be of sliding type. Rolling shutters of adequate size shall be provided to permit the entry of largest equipment.

16.0 CONDENSER COOLING WATER SYSTEM

16.1 RCC cooling water channel shall be of rectangular shape and designed as a water retaining structure, it shall be an extension of the CW basin. Dimension of the channel shall be decided on the basis of the quantity of water to be carried by the channel. Floor of the channel shall be given a mild slope to ensure necessary velocity of flow. The top of the channel shall be kept same as that of CW basin and provided with suitable galvanised M.S pipe hand railing on either side. The channel shall smoothly discharge into a sump in front of the pumps area. It is suggested that the bottom of the sump shall be kept flat.

16.2 Depth of C.W sump shall be decided based on submergence requirement of the C.W pumps at the lowest water level in the sump. Sump shall be provided with rung ladder at two corners constructed of galvanised steel. Top of the sump shall be kept 500 mm above channel level and handrail of galvanised M.S.pipes shall be provided for the entire length on either sides. Water level indicator (float type) shall be provided in the pump sump on either side to observe the depth of water. The sump shall be fully covered by RCC slab with provision of manholes at the location of the rung ladder. 17.0 Cooling Water Pump House, Fore bay and CW pipelines.

CW Pump House and Fore bay

17.1 Dimension of the pump sump shall be so selected as to prevent dead water areas, reverse currents, flow separation and eddies. Recommendations of British Hydromechanics Research Association (BHRA) and Hydraulic Institute Standards shall be followed. Pump sump shall be designed as water retaining structure. Each sump shall be provided with stainless steel groove for inserting coarse screen, fine screen and stop logs. Grooves for stop log shall be provided before and after the screens. Where as number of coarse screen and fine screen shall be the same as the number of pump sumps the number of stop log shall be a minimum of two. Sufficient paved space shall be provided to keep the stop log when not in use and also for maintenance of screens. Each individual pump sump shall also be provided with a drain sump to empty the sump for attending to maintenance of pump.

17.2 Proper rubber seal of minimum 14 mm thick shall be provided for the stop logs so as to avoid any leakage of water. Rubber seal provided for the stop logs shall be tested in accordance with the relevant Indian standards for water tightness and smooth operation in dry and wet conditions. The



SECTION: D4.5


leakage through the rubber seal shall be measured and it should not be more than 5 litres/min/meter length of seal under maximum head.

17.3 The pump house shall be of RCC structure with EOT crane. The cladding shall be in brick masonry infill. Ventilation and natural lighting shall be provided with aluminium glazed windows. Minimum of two flush welded steel doors shall be provided for movement of personnel. While planning crane runway girders, due care shall be taken to ensure that all pumps can be erected and maintained using the crane. Maintenance bay of the pump house shall have RCC grade slab with granolithic finish and non metallic floor hardener. Motor floor shall also have similar finish. Roof shall be provided with minimum 1 in 100 slopes for drainage towards the fore bay side. Roof shall be given elastomeric water proofing treatment. Approach to roof shall be provided with steel cage ladder. 17.4 Pumps generally have common base plate with the motor and hence the pump foundation is provided at the motor floor level. A thrust block shall be provided connecting the pump and motor floor to resist the pump thrust. Staircase shall be provided from the pump floor to motor floor. Motor floor shall be given handrail on the two sides. Pump maintenance area shall be provided on one side at the pump floor level. 17.5 All doors shall be flush welded steel construction.

17.6 An annex to the C.W pumps area shall be provided in RCC framed structure to accommodate chlorinator room, chlorine cylinder storage room and toilet block. Side cladding shall be of brick/concrete block work except in Chlorine cylinder storage area where brick wall is provided only to a height of 1 m. All floors and roofs shall be of RCC. Roof shall be given proper slope and heavy duty water proofing. Rain water down comers shall be of galvanised MS pipes conforming to IS:1239. Roofs shall be made accessible by MS cage ladder. 18.0 CW Inlet and Outlet Conduits

18.1 From the CW pump house, the CW flow will be conveyed to the condenser located in the gas turbine & steam turbine generator building through an inlet conduit designed to carry the required CW flow with a maximum velocity of 1.8 m/sec. The hot water from the condenser will be conveyed to the cooling tower by a CW outlet conduit which will be similar to CW inlet conduit. Both inlet and outlet conduits shall be of mild steel and provided with 15 mm thick cement mortar lining on the inside and RC encasement of thickness not less than 250 mm on the outside. However, the actual encasement thickness shall be based on stability against uplift with highest possible ground water level. Further, It has to be designed for traffic load at road crossings. Following design requirements shall be met :



SECTION: D4.5


(a) Provide a minimum clear distance of 1.5 m between ground level and the top of RC encasement.

(b) The design pressure shall be the highest of the following :

(i) Pump shut off head + Static head difference between normal water level at CW sump and the lowest invert elevation of the CW conduit.

(ii) Maximum pressure due to surges.

(a) The conduit shall also be designed for vacuum pressure inside and overburden pressure outside

(b) The design shall be checked for other loading combinations of surcharge, transformer load, ground water pressure etc.,

(c) Manholes shall be provided at a maximum spacing of 150 m in straight reach of conduit. One manhole shall be provided at all horizontal bends and one at the lowest stretch between two vertical bends.

18.2 Cement mortar lining The work shall be carried out as per the standard of American water works association. All work shall be performed by trained personal under the supervision of experienced skilled person. Application of lining shall be fully mechanised and necessary machinery / equipment shall be made available by CONTRACTOR at the time of execution. The lining shall be properly cured and tested.

18.3 Material: 18.3.1 Cement used shall be Ordinary Portland cement confirming to IS-8112.

Rapid hardening cement can be used if the available OPC is not of a suitable fineness.

18.3.2 Sand used shall be of River sand confirming to IS-11906 and sieved as per IS-460.

18.3.3 Water for mixing mortar and curing shall be clean and free of mud, oil, and other organic material or other deleterious substances. Preferably Potable water shall be used.

18.3.4 Proportion of cement and sand in the mortar for the lining shall be 1 part of Portland cement to 1.5 parts of sand by volume. The exact proportion shall be determined by the characteristics of the sand used.

18.3.5 The water content shall be the minimum quantity that produces a workable mixture, with full allowance made for moisture collecting on the interior of the pipe surfaces. Slump test shall be made periodically on freshly mixed mortar immediately before mortar is conveyed to the lining machine. Nominal slumps of cement-sand mortar mixes for application shall be as per the relevant standard.



SECTION: D4.5


18.3.6 The lining shall be minimum 15mm uniform thickness and shall be within the allowable tolerance, except at joints. CONTRACTOR shall arrange the thickness-measuring device.

18.4 Methods of construction: 18.4.1 All access openings necessary for the lining work shall be prepared and

closed by CONTRACTOR after completion of the work.

18.4.2 Cement mortar lining shall be taken up after the pipeline is hydro tested. The section of the pipe line to be taken up for lining shall be cleaned thoroughly using mechanical steel wire brushes or by methods approved by the owner to remove corrosion, oil, grease etc.

18.5 Mortar lining: 18.5.1 Clean up ahead of machine. Before the lining machine travels through a

pipeline, all foreign material shall be removed. This includes sand and loose mortar that might have accumulated since the preparation of surface was completed. The Lining shall be applied in one course by a machine travelling through the pipe and distributing the mortar uniformly across the full section and long radius bends of the pipe. The discharge shall be from the rear of the machine so that the newly applied mortar will not be marked. The rate of travel of the machine and the rate of mortar discharge shall be mechanically regulated to produce a smooth surface and uniform thickness throughout. The mortar shall be densely packed and adhere wherever applied.

18.6 Curing. Curing operations shall begin following completion of the machine placement of the mortar lining in a section of pipeline. The section of pipe shall be closed with airtight covers over all openings and shall be maintained in a moist condition. When a section of pipeline has been completed, CONTRACTOR shall be responsible for curing the mortar lining until the section is matured. Sprinkling exterior. The exterior surfaces of pipe exposed to sunlight shall be sprinkled with water in the day time during the period of lining, finishing and curing when such a sprinkling is required, as determined by CONTRACTOR or the owner, to prevent cracking of the lining.

18.7 Inspection The entire procedure for applying cement- mortar lining shall be subject to continuous inspection by the owner, but such inspection shall not relieve CONTRACTOR of the responsibility to furnish material and perform work accordance with the standards. The owner shall have free access to all areas, places, or facilities concerned with the furnishing of material or the performance of work under the provisions of the standards.

19.0 Clarifiers, Chlorination building, DM Clarified water Storage Tanks, Filter water storage tanks and Pump House.



SECTION: D4.5


19.1 Clarifier of clariflocculator type as per the system requirement shall be installed. Necessary sludge pit, clarified water storage tanks etc of required capacity shall be provided. The requirement of clarification system shall be as per the Mechanical Specification.

19.2 Minimum grade of concrete shall be M25 and the structure shall be designed as cracked section with limiting crack width to 0.1 mm section in accordance with IS: 456 with suitable provision of contraction, expansion and construction joints. Minimum thickness of any reinforced concrete element except launders shall be 225 mm. Minimum thickness of launders / channels shall be 150 mm. The base slab of clarifier shall be designed as structural slab. Pressure relief valves in base slab are not acceptable since base slab may come above the ground level.

19.3 Framework for the divider wall in the clariflocculator between flocculation and clarification zones shall be RCC construction. Infill shall also be of RCC walls.

19.4 Pipes from flash mixers to clarifiers shall be of Hume pipe Class P1 as per IS 458 and necessary concrete encasement for the whole length shall be done.

19.5 The clariflocculator structure shall be checked for earthquake condition also in addition to wind & other loads.

19.6 The Pump house shall accommodate pumps for fire protection, service water, potable water, DM plant, make-up water, etc. The size of the building shall be decided based on the size of the pump, their maintenance, handling requirements, space for MCC room etc. The building shall be designed is an R.C.C framed structure with brick cladding, steel glassed window, flush steel doors and rolling shutters for equipment entry. External finish shall be Granular finish (Vineratex or equivalent) of 2 mm thick over plain faced plaster.

20.0 Make up water pipe line

20.1 All the conduits are designed to convey the required flows by gravity with a maximum velocity of 1.8 m/sec. The conduits shall be provided with cement mortar lining of 15 mm thickness lining (which shall be carried out as per detail specification explained else where in this document) internally and RC encasement of minimum thickness 250 mm externally. However, the actual encasement thickness shall be based on stability against uplift with highest possible ground water level. Further, It has to be designed for traffic load at road crossings. A minimum clearance of 1.5 m between ground level and the top of RC encasement shall be maintained. Specifically, the following design requirements shall be met:

20.2 The design pressure for the conduits shall be 1.5 times the static head 20.3 Adequate number of air valves and manholes as required hall be

provided at appropriate locations along the length of the conduit.



SECTION: D4.5


21.0 Cooling Tower 21.1 Cooling towers shall be of Induced draft type. For detailed

specification of the cooling towers, refer to mechanical section of this document. Detailed specification for civil and structural portion of the towers are covered else where in this document.

21.2 The cooling tower shall be capable of cooling the rated quantity of water through the specified thermal range at the design wet bulb temperature and it shall conform to the other design parameters as stipulated in mechanical section of this document.

21.3 The scope of work shall include for design, construction, supply of all material, basin,fill with its supporting structure, staircases / walkways / platforms with hand railing, cold water outlet channels including gates, screens with handling arrangement, painting, access doors, water distribution system, aviation warning system, lighting, lightning protection system, with their associated hardware, etc., complete all as required to give satisfactory performance and as stipulated in various clauses in this document. 21.4 In the event, CONTRACTOR has quoted in collaboration with another

firm (either Indian or foreign), each and every drawing and design calculations submitted shall bear collaborator’s seal and signature indicating their approval. CONTRACTOR shall also furnish back-up guarantee for the performance of the cooling tower from the collaborator.

22.0 SERVICE WATER OVERHEAD TANK 22.1 This shall be of RCC construction with necessary piping, access stairs,

pump room, etc., complete. For other details refer to mechanical section of this document.

23.0 PIPE AND CABLE RACKS & PIPE SLEEPERS 23.1 All cable and pipe routing in out lying areas shall be clubbed and shall run

over ground on structural steel pipe / cable racks at a height not less than 3000 mm above graded level. In case cable route is not envisaged in the area, pipe shall be routed on ground over RCC pedestals at a height not less than 500 mm above grade level. Where the pipes cross roads / railway clear headroom shall not be less than 7000 mm. The racks can be multilayered. Cable shall normally be laid above the pipes.

23.2 The racks are generally designed as a rigid frame in the transverse direction and braced in the longitudinal direction. Expansion provision shall be provided wherever there is a change in direction or where length of the rack exceeds 100 metres. Access ladder shall be provided at suitable location. Where so required chequered plate platforms shall be provided for maintenance purpose. Pipe rack columns shall be supported on RCC foundations with bottom of base plate about 300 mm above ground level. The pipe rack interconnecting the HRSGs should have a walkway of clear width of 900 mm minimum. This walkway should interconnect to the HRSG platform and the deaerator platform of the BFP structure.



SECTION: D4.5


24.0 GUARD POND

Guard pond shall be of RCC construction with necessary piping, pump room, etc., complete. The pond shall be designed as a cracked section with limiting crack width to 0.1 mm section in accordance with IS: 456 . For other details refer to mechanical section of this document.

25.0 FUEL GAS RECEIVING AND METERING STATION

Necessary building / sheds and foundations shall be provided for fuel gas metering station duly considering the site conditions and statutory requirements.

26.0 DEAERATOR, BFP BUILDING, MCC ROOM The building shall be of structural steel frame with moment connection in the transverse direction and bracing in the longitudinal direction. Ground floor shall houses MCC room & BFP’s. Deaerator shall be on placed on the in-situ RCC slab provided over structural steel beams.

27.0 AIR COMPRESSORS 27.1 This shall be a single storied RCC framed structure and the dimensions of the building

shall be decided by taking into account the maintenance requirement. Side cladding and roofing shall be colour coated galvanised sheeting over 3000 mm high brickwork. The foundation of Compressor shall be isolated from the floor. Hoist of suitable capacity if required shall be provided to maintain the required equipment. Adequate ventilation and lighting shall be provided with steel glazed side hung windows. Noise level outside shall be with-in permissible limits.

27.2 All trenches shall be of RCC and shall be designed as water retaining structure. There shall be no entry of cables / pipes to these trenches below grade level from outside. All these trenches shall be covered with chequered plate over steel framing. Adequate number of sumps shall be provided to drain these trenches. Main door shall have a rolling shutter of adequate capacity to allow entry of Compressor sets. For compressor Air receiver and Air drier can be supported from RCC grade slab. Dimension of the building shall be decided to suit the dimension of the equipment being supplied duly taking into account maintenance requirements.

28.0 Fuel GAS CONTROL ROOM.

The size of the building shall be decided based on the size of the pump, their maintenance, handling requirements, space for MCC room etc.The building shall be designed is an R.C.C framed structure with brick / solid concrete block & cladding, steel glassed window, flush steel doors and rolling shutters for equipment entry. External finish shall be Granular



SECTION: D4.5


finish (Vineratex or equivalent) of 2 mm thick over plain faced plaster. Roof shall be given elestomeric water proofing treatment as specified.

29.0 Gas Conditioning Skid

Necessary building / sheds and foundations shall be provided duly considering the site conditions and statutory requirements.

30.0 Sewage treatment plant The total sewage from power plant site is required to be treated for which a tertiary sewage treatment plant is to be constructed by EPC contractor and shall be designed in accordance with relevant BIS/CPHEEO standards and state government pollution board norms. The tertiary treated water is proposed to be utilised for gardening and other miscellaneous use. In addition to the sewage treatment, the scope shall also include collection of sewage from power plant area including the supply and construction of sewers. The process for sewage treatment and collection of sewage including sewer design has to be approved by the Owner.



SECTION: D4.5

LIST OF BUILDINGS / STRUCTURES

LIST OF BUILDINGS / STRUCTURES (Brief specification of buildings)

Sl No 1

2

3

4 5 6 7

8 9

Description

GTG and STG Building

Control and Switchgear Building (G + 3 floors)

Heat Recovery Steam Generator

BFP Building including MCC

Cooling tower (IDCT)

Air Compressor

Pipe / Cable Racks and pipe sleepers

DM Plant building including plant, DM tanks

Service Water Overhead Tank

Type of Construction

Structural steel columns with Roof truss. Brick / solid concrete block as in fill wall for side cladding up to a height of 3000mm above FFL & 0.5 mm thick pre-coated galvalume sheeting with sandwich panels supported on structural steel for rest of height and roof.

Reinforced Concrete frame constructions with Solid concrete block / brick in fill walls.

Structural steel Column / beams / bracings. Reinforced Concrete frame constructions with Solid concrete block / brick in fill walls. Reinforced Concrete frame constructions with Solid concrete block / brick in fill walls. Reinforced Concrete frame constructions with Solid concrete block / brick in fill walls. Structural Steel construction with foundation Reinforced Concrete frame constructions with Solid concrete block / brick in fill walls with semi outdoor type with covered roof.

Reinforced Concrete constructions.



SECTION: D4.5


LIST OF BUILDINGS / STRUCTURES (Brife specification of buildings)

Sl No

Description Type of Construction

10 DM water storage tank

11 CW Pump House

12 Condensate storage Tank 13 Chlorination Building 15 Guard Pond

16 Neutralisation Pit

Transformers

17 Foundations, Fire walls, Cable trenches etc,

18 Fuel gas Metering Station

Reinforced Concrete constructions. Reinforced Concrete frame constructions with Solid concrete block / brick in fill walls

Structural steel tanks with RC ring foundation Reinforced Concrete frame constructions with Solid concrete block / brick in fill walls

Reinforced Concrete Constructions.



Reinforced Concrete frame constructions with Solid concrete

Gas Conditioning Skid, Control room,

19 Switchyard (220KV), Cable trenches etc,

block / brick in fill walls with allround fencing etc, Structural Steel Works



SECTION: D4.5


LIST OF BUILDINGS / STRUCTURES (Brife specification of buildings)

Sl No

Description Type of Construction

20 Road 21 Drains

22 Filter water storage tank and pump house 23 Sewage treatment plant

As per specification requirement

RCC drains

Reinforced Concrete frame constructions with Solid concrete block / brick in fill walls

Package unit

-



SECTION: D4.6a

PART A - GENERAL REQUIREMENTS

1.0 General Requirement of building / Structures 1.1 Design and construction of buildings, structures etc. shall take into account requirements for operation and maintenance of all equipment and its users. The buildings shall have good architectural features. The surrounding areas shall be properly micro levelled and graded.

1.2 Architectural Concept for Buildings

The architectural design concept of buildings shall be evolved considering the functional, technical and other requirements for efficient operation, ensuring comfortable working environment for personnel, satisfying the aesthetic requirements. Special care shall be taken to provide elegance and aesthetics, with effective use of appropriate treatment, materials, fittings and finishes. To achieve above objective CONTRACTOR shall employ a qualified architect/ architectural firm to carry out all designs and hold all other architectural responsibilities for the project.

1.3 The CONTRACTOR shall obtain and be conversant with all laws, by- laws and regulations of local and Statutory Bodies as applicable to the project. The architectural concept evolved should also take care of these requirements. The CONTRACTOR shall provide the drawings and documents for such statutory approvals.

1.4 Parapet, Chajjas over window and door heads, architectural facias, projections, etc., shall be provided with drip course in cement sand mortar 1:3.

1.5 Architectural Concepts

a) Layout of the plant area shall have definite hierarchy of road network depending upon its usage, aesthetic, visual sensibilities for creating road vistas, focal points, building back drops, building frames. General layout shall be evolved taking over the basis of landform and local climate and due consideration shall be given to orientation and wind direction. The resulting built mass shall present a definite image width in distinct vocabulary in the form of landmarks, nodes and skyline.

b) Main Plant building shall be architecturally treated in such a way hat it retains a monumental scale, yet presents a pleasing composition of mass and void with suitable and functionally designed projections and recesses. The overall impact of the building shall be



SECTION: D4.6a


one of aesthetically unified architectural composition having a comprehendible scale, blending tonal values with the surroundings and taking full consideration of the climatic conditions, the building orientation and the existing structures nearby.

c) All other buildings and structures shall be architecturally treated in such a way so as to be in complete harmony with the main plant, surrounding structures and environment. Local architectural characters and materials may be judiciously imbibed. The building shall be designed initiating an architectural control common to all buildings. The architectural control shall be clearly spelt out in terms of scale, man and form.

d) Overall colour scheme of the plant and other buildings shall be designed judiciously and in a comprehensive manner taking into a account the mass and void of buildings, its facade, equipment, exposed structural elements, piping, trestles, bus ducts and other service elements.

e) Overall emphasis shall be on developing an eco-friendly architecture, merging with the nature with its own sustainable energy management systems.

The scheme shall be conceptually finalised in totality including that of equipment so that the proper coordination with other agencies can be taken up at appropriate time.

B) Architectural Design

a) Natural light shall be used to the maximum extent, especially in the form of north light/sky light. For adequate light and ventilation, National Building code recommendations shall be followed.

b) Entrance canopies chajjas (projections, recesses) over openable windows and door openings on exterior facades shall be provided.

c) All the buildings shall be architecturally designed to meet the National Building Code (SP: 7) norms and local building bye laws, wherever applicable.

d) Architectural design and detailing aspects of all the buildings shall be rendered through professional services of an Architect. Statutory requirements may be required to be met with, wherever essential. The Architect Consultant shall be of



SECTION: D4.6a


National/International repute having experience in similar kind of works. The consultant shall evolve the design philosophy based on Employer's guidelines and shall present it in the form of presentation drawings, Prospective views, 3-D Models and detail drawings.

1.6 Service utility ducts shall be planed to take care of all piping such that no pipelines are visible from out side. However proper access to the ducts shall be provided at each floors along with platform in the duct for the purpose of maintenance.

2.0 ROOF ACCESS

All roofs shall be provided with access through a staircase/ cage ladder. Minimum 1000 mm wide access path shall be provided with tiles to approach equipment on roof.

3.0 PLATFORMS AND WALKWAYS

3.1 Platforms shall be provided to all major equipment, which are not directly accessible from the floors, for maintenance. Platforms and connecting walkways shall have a minimum width of 750 mm. Platforms in front of the entry shall be at least 900 mm wide. Platforms located close to each other shall be connected with walkways.

3.2 All steel platforms above grade level shall be constructed with kick plates at edge of the platform to prevent tools or materials from falling off. It shall consist of 8 mm thick steel plate projecting 100 mm above the platform surface. Kick plate shall be painted with the same type of coating as the material to which it is attached.

3.3 Continuous walkway, at least 500 mm wide shall be provided along the crane girder level with handrails on both sides of the building. Approach to EOT crane shall be ensured by Cage ladder or staircase

4.0 STAIRS AND LADDERS

4.1 Steel Stairs

All steel staircases shall normally have minimum clear width (back to back of stringer) of 1000 mm and maximum inclination with horizontal of 35.750. However, in case of space restriction, minimum clear width upto 750 mm and slope upto 450 may be provided. The vertical height between successive landings shall not exceed 5 m.



SECTION: D4.6a


Channels (minimum MC200) shall be provided as stair stringers. Treads shall be minimum 275 mm wide of chequered plate/grating, with suitable nosing, and spaced equally so as to restrict the rise to maximum 180 mm.

4.2 Steel Ladders

Ladders shall be provided to platforms, walkways, instruments and equipments which do not require frequent access. Ladders shall preferably be vertical and its angle with vertical shall not exceed 50. Ladders shall be of minimum 450 mm clear width with 20 mm diameter MS rungs spaced at 300 mm (maximum). Ladders shall be provided with a safety cage of minimum 750 diameter clear when the top of ladder is more than 4.5 m above the landing level. However safety cages shall start at 2.5 m above the lower landing level.

4.3 RCC Stairs

All stairs shall have maximum riser of 180 mm and a minimum tread of 250 mm. However, for administration buildings riser shall be limited to 150 mm and tread width of 300 mm. Minimum width of stairs shall be 1200 mm generally. All stairs normally shall have not more than 15 risers in one flight. Aluminium angle nosing with minimum 50X25X3 angle or PVC nosing shall be provided for edge protection of RCC stairs.

5.0 HANDRAILS

5.1 Handrails shall be provided at appropriate places to ensure safety e.g. around all floors/roof openings, projections / balconies, walkways, platforms, steel stairs etc.

5.2 All handrails shall be of 50 mm nominal bore MS pipes (medium class) as per IS :1161 galvanised using 750 gm/sq. m of zinc. Handrails for platforms, walkways and projections shall be a two-rail system with the top rail 1000 mm above the walkway surface and the intermediate rail 450 mm below the top rail. Handrail post spacing shall be limited to 1500 mm as far as possible but can be proportioned to the length of the protected horizontal opening. In such a case spacing shall not exceed 1850 mm center to center of posts. Handrails shall be shop fabricated for specific locations and field welded or bolted to the erected structural steel. For platforms at elevation more than 30 m, three rail system with top rail at 1500 mm shall be adopted.



SECTION: D4.6a


5.3 For RCC stairs, handrails with 20 mm square MS bar balustrade with suitable MS flat & aluminium / Teakwood handrail shall be provided, unless specifically mentioned otherwise.

6.0 EDGE PROTECTION

Wherever possible around floor openings an RCC kerb of 100 mm wide 150 mm high shall be provided. All concrete edges, where breakage of concrete corner is expected, shall be provided with angles at least L 50x50x6 with lugs for edge protection e.g. all round the cut-outs/openings in floor slab, edges of drains supporting grating covers, edges of RCC cable/pipe trenches supporting covers, edges of manholes supporting covers and supporting edges of precast covers etc.

7.0 ANCHOR BOLTS AND INSERT PLATES

7.1 Anchor bolts shall be designed for working stress, in tension and shear, for embedded length of the anchor bolts and pipe sleeves. Shear and crushing strength of concrete shall also be checked.

7.2 Insert plates shall be designed/checked for shear and bending moment. All lugs shall be checked for tension. Bond strength of concrete shall also be checked. Lugs using steel bars shall preferably be fillet welded to the plate to transfer full strength of the lug.

8.0 VERTICAL HEADROOM

8.1 All accessible areas shall be provided with a minimum clear headroom as follows, unless otherwise specified:

Finished floors to ceiling (buildings) : 3000 mm

Doors, Walkways, Platforms, Stairs etc. : 2100 mm

False ceiling of office areas : 2400 mm

Walkway above false ceiling : 1000 mm

Safety cage for ladders : 2500 mm

Access for forklift trucks : 2800 mm

Main roads/Railway crossings & crane access: 9000 mm

Other plant roads and truck access : 6000 mm



SECTION: D4.6a


Cable & Pipe rack : 3000 mm

(except Road/Rail crossings)

9.0 EXPANSION/CONSTRUCTION JOINTS

9.1 Expansion and construction joints shall be provided wherever required. All expansion and construction joints of water retaining structures in RCC shall be made watertight using PVC ribbed water stops with central bulb. However, kicker type (externally placed) PVC water stops may be used for the base slabs and in other areas where it is required to facilitate concreting. The minimum thickness of PVC water stops shall be 6 mm and minimum width 225 mm. At other joints these shall be 150 mm wide.

9.2 Two part polysulphide sealant conforming to IS:12118 shall be used for sealing of joints in contact with water. For other cases, bitumen sealing compound conforming to IS:1834 shall be used. Preformed bitumen impregnated fibre board conforming to IS:1838 shall be used as joint filler.

10.0 BRICK / STONE MASONRY AND PARAPET WALL 10.1 All masonry works shall be designed in accordance with IS:1905, IS:2212, IS:4326, IS:2185 and other relevant IS codes as applicable. Structural design of load bearing and non-load bearing walls constructed with solid burnt clay bricks / fly ash bricks confirming to IS: 12984 or concrete blocks shall be in accordance with criteria specified by Section 4 of National Building Code of India Part VI.

10.2 All walls shall be non-load bearing infilled panels walls. External walls of all buildings shall be at least one brick thick. All internal wall shall be at least one brick thick except for internal partition walls for office area, canteen, change rooms, first aid rooms and toilets which may be half brick thick. RCC bands (transoms and mullions) shall be provided wherever necessary to curtail the unsupported length/width of the wall.

10.3 50 mm thick DPC (1:1.5:3) with water proofing admixture followed by two layers of bitumen coating 85/25 grade as per IS:702 @ 1.7 kg./sq.m shall be provided at plinth level before starting masonry work.



SECTION: D4.6a


10.4 Bricks having minimum 35 kg/sqcm compressive strength shall be used for non load bearing super structure brick work. Cement sand mortar 1:6 for one brick thick wall and 1:4 for half brick thick wall shall be used. For half brick walls, RCC transoms and mullions shall be provided. Transoms shall be provided at lintel/door height. The spacing of the mullions shall not exceed 2000 mm center to center. The size of transoms/mullions shall be minimum 115 mm square with 4nos., 8 mm dia. bars and 6mm stirrups at 150 mm centers. 10.5 Type, thickness and height of external wall, facing the transformer yard to take care of fire accidents in transformer yard shall be according to the requirements of Tariff Advisory Committee. 10.6 Even where metal cladding is specified, for initial 3 m height from the

ground level, minimum one brick thick masonry wall shall be provided.

10.7 All upstands and parapet walls on roof shall be of RCC construction,

minimum height of parapet walls shall be 750 mm and thickness 125 mm.

11.0 DRAINAGE 11.1 Floor drainage 11.1.1 For all buildings and areas, suitable arrangement for draining out water collected from equipment blowdowns, leakage, floor washing, fire fighting, etc. shall be provided on each floor. Gully traps, inspection pits, collecting pits etc. shall be located suitably and designed considering flow volume, easy access, maintenance and safety. 11.1.2 All drains inside the building shall have minimum 40 mm thick galvanised grating covers. In areas where heavy equipment loads would be coming, precast RCC covers shall be provided in place of grating. These drains shall lead the water to drain sump. 11.1.3 Garland drains shall be provided around all buildings to receive the drainage water from roof and floor and lead them to the plant storm water drainage system. 11.2 Roof drainage



SECTION: D4.6a


11.2.1 Roof drainage system shall be provided for quick and efficient draining of rainwater from roof to avoid seepage and damage to roof. The runoff gradient for the roof shall not be less than 1 in 100. Roof drainage system shall consist of roof drain heads, rainwater down take pipes and fixtures. System shall be designed to handle design requirements for the specific site and shall be in accordance to stipulations of IS:1742 and IS:2527. Roof drains shall conduct water to storm drains through down take pipes. 11.2.2 Rain water down take pipes shall be of UPVC pipe of Class - 3 conforming to IS : 4985. 11.3 Sumps

In case of underground structures, sumps with pumping arrangement shall be provided at suitable location to collect and pump out any incidental water collection to nearest storm water drains.

12.0 WATERPROOFING OF UNDERGROUND STRUCTURES 12.1 All underground structures like water retaining structures shall have plasticiser cum waterproofing cement additives conforming to IS:9103. In addition, limits on permeability as given in IS:2545 shall also be met with. The concrete surface of these structures in contact with soil shall be provided with minimum two coats of bituminous painting of grade 85/25 conforming to IS:702 @ 1.7 kg/sq.m (minimum) for water / damp proofing. Also provision shall be made on the inner surface of walls and base slab, so that water proofing grouting can be injected after hydro testing case of leakage. 12.2 In addition to above water proofing treatment, approved stone cladding with water proofing joints shall be constructed on outer faces including below base slab for all under ground structures to prevent of water being entering to the sump / tank etc. The stone cladding shall be follows.

a) For base slab, a layer of PCC 1:4:8 shall be laid. Over PCC layer, two coats of acrylic polymer modified cement based flexible water proofing membrane of approved make laid as per manufacture’s specification and instruction. Over water proofing membrane, 25mm thk CM 1:3 mixed with approved water proofing compound



SECTION: D4.6a


at the rate specified by the manufacturer shall be applied. Over water proofing compound, protective layer of 15mm thk kota / cuddapa or equivalent stone with joints sealed with CM 1:3 shall be laid. Over this stone layer, RCC base slab shall be cast.

b) For side walls, two coats of acrylic polymer modified cement based flexible water proofing membrane of approved make laid as per manufacture’s specification and instruction shall be applied to the sides of RCC walls. 25mm thk CM 1:3 mixed with approved water proofing compound at the rate specified by the manufacturer shall be applied over it. Protective layer of 15mm thk kota / cuddapa or equivalent stone with joints sealed with CM 1:3 shall be laid. Water proofing compound. 25mm thk CM 1:3 mixed with approved water proofing compound at the rate specified by the manufacturer shall be applied.

13.0 ANTI TERMITE TREATMENT

Pre-constructional anti termite treatment shall be given to all vulnerable areas susceptible to termite attack and shall include column pits, wall trenches, foundations, filling bellow the floors etc. as per IS: 6313 and other relevant Indian Standards.

14.0 PLINTH LEVEL

14.1 Finished ground floor level (plinth level) of all buildings and pump

houses shall be minimum 300 mm above the formation level/grade level.

14.2 All cable vaults shall be located above ground level i.e. cable vaults

shall not be provided as basements in the buildings. 14.3 Finished floor levels of HRSG area / transformer area yard paving

shall be kept 150 mm lower than the finished floor level of turbine building.

15.0 STATUTORY REQUIREMENTS 15.1 All the applicable statutory rules pertaining to Indian Factories act, Factory rules of state government, Fire safety rules of Tariff Advisory Committee, Water act of Pollution Control Boards, Explosives act



SECTION: D4.6a


etc. and stipulations of other relevant statutory authorities shall be taken into consideration at the time of design.

15.2 Provisions of safety, health and welfare according to Factories act shall be complied with design stage. These shall include provision of continuous walkway (minimum 500 mm wide) along crane-girder at crane girder level on both sides of the building, comfortable approach to EOT crane cabin, railings, fire escape, locker room for workmen, pantry, toilets, rest room etc. 15.3 Adequate number of fire escapes shall be provided in a building. Fire proof doors, number of staircases, fire separation walls, lath plastering on structural steel member (in fire prone areas) shall be made according to the recommendation of TAC. For fire safety requirements of buildings IS:1641 and IS:1642 shall be followed in addition to TAC requirements. All masonry firewalls shall be minimum 350 mm thick and RCC firewall shall be minimum 200 mm thick. 16.0 TOILETS

Minimum one number main toilet block each (for male and female) with required facilities shall be provided on each floor of Main plant building, and Admin / Service/ office building. Attached toilets shall be provided for all senior executive rooms and conference rooms. All other buildings shall have minimum one toilet block each. The facilities provided in the toilet block shall depend on the number of users. However, minimum facilities to be provided shall be as stipulated in subsequent clause. IS:1172 shall be followed for working out the basic requirements for water supply, drainage and sanitation. In addition, IS:2064 and IS:2065 shall also be followed. i) Each toilet block shall have the following minimum facilities. Unless specified, all the fittings shall be of chromium plated brass (fancy type).

a) WC (Indian type, Orissa pan (580 x 440mm) as per IS : 2556 with all fittings including photo-voltaic sensor operated flushing system of appropriate capacity and type.



SECTION: D4.6a


b) Urinal with all fittings with photovoltaic control flushing system as per IS: 2556 .

c) Wash basin (oval shape) with photo-voltaic control fittings as per IS : 2556 to be fixed on concrete platform finished and under fixed with 20mm thick polished granite stone and float glass mirror (600 x 450 x 5.5mm) with bevelled edges. d) 25mm dia Stainless steel towel rail (600 x 20mm)., liquid

soap holder cum. dispenser with all fittings. e) Stainless steel liquid soap holder cum dispenser .-2 nos f) Janitor room g) Provision for installation of water cooler with recessed floor

and stainless steel grating for draining of spillage water, including provision for potable water supply connection.

h) Electric operated hand dryer with photo voltaic control j) Provision of ventilation shaft. Attached toilets provided for senior executive rooms shall and conference room have one no. European WC, wash basin (oval shape) with all fittings as per IS : 2556 to be fixed on concrete platform finished and under fixed with 20mm thick polished granite stone and float glass mirror (600 x 450 x 5.5mm) with bevelled edges, 1 towel rail, 1 liquid soap holder cum dipensor with all fittings. WC shall be of western type 390 mm high as per IS:2556 (Part-2) with toilet paper roll holder and all fittings including flushing valve of appropriate capacity and type. Unless specified all other fitting and fixtures in the toilet shall have same specifications as stipulated in above clause with photo- voltaic sensor/controls. Sunken floor shall be avoided as far as possible. The same shall be achieved by providing false ceiling for roof slab below toilets. So that the maintenance of pipe line will be easier.



SECTION: D4.6a


17.0 SITE LEVELLING 17.1 Earth to be used for filling purpose shall be sand or other inorganic materials and they shall be clean and free from shingle, salts, organic, large roots and excessive amount of sod, lumps, concrete or any other foreign substances. All clods shall be suitably broken to small pieces. Sand used for filling shall be clean, medium grained and free from impurities. Fines less than 75 microns shall not be more than 20 %. In any case, the materials to be used for filling purpose shall have the prior written approval of the Engineer. 17.2 Fill shall be placed in horizontal layers not exceeding 300 mm compacted thickness. Each layer shall be watered and compacted with proper moisture content and with such equipment as may be required to obtain a compaction / density of 95% of Standard Proctor Maximum Dry Density. 17.3 Compaction shall be carried out with 12 tonne rollers smooth wheeled, sheep foot or wobbly wheeled as directed by the Engineer. Each layer shall be wetted or the material dried by aeration to a moisture content of 3-5% above the optimum. Each layer shall be watered, rammed and compacted and tested for ensuring the desired degree of compaction.

18.0 CONSTRUCTION METHODOLOGY 18.1 Construction and erection activities shall be fully mechanised from

the start of the work. 18.2 All excavation and backfilling work shall be done using excavators, loaders, dumpers, dozers, poclains, excavator mounted rock breakers, rollers, sprinklers, water tankers, etc. Manual excavation can be done only on isolated places with specific approval of engineer. 18.3 For controlled rock blasting specialized agency, equipped with sensors to assess the impact of the blast on the adjoining existing structures, shall be employed. 18.4 Dewatering shall be done using the combination of electrical and

standby diesel pumps.

18.5 Pile installation equipment suitable for flushing with air lift technique shall be used for construction of bored piles. 18.6 For concreting, weigh batching plants, transit mixers, concrete

pumps, hoists, etc. shall be used



SECTION: D4.6a

PART A - GENERAL REQUIREMENTS 18.7 All fabrication and erection activities of structural steel shall be carried out using automatic submerged arc welding machines, cutting machines, gantry cranes, crawler mounted heavy cranes and other equipment like heavy plate bending machines, shearing machines, lathe, milling machines, etc. Use of derricks shall not be permitted. Special enclosures, for blast cleaning of steel structure surface preparation, shall be used. 18.8 All handling of materials shall be with cranes. Heavy trailers shall be

used for transportation. 18.9 Mechanized modular units of scaffolding and shuttering shall be

used. 18.9 Grouting shall be carried out using hydaulically controlled grouting

equipment. 18.10 Roadwork shall be done using pavers, rollers and premix plant. 18.11 All finishing items shall be installed using appropriate modern mechanical tools. Manual punching etc. shall not be permitted. 18.12 Heavy duty hoists for lifting of construction materials shall be deployed. Compressors for cleaning of foundations and other surfaces shall be used. 18.13 Field laboratory shall be provided with all modern equipment for survey, testing of soil, aggregates, concrete, welding, etc. For testing of steel works, ultrasonic testing machines, radiographic testing machines, dye penetration test equipment, destruction testing equipment, etc. shall be deployed.

18.14 All persons working at site shall be provided with necessary safety equipment and all safety aspects shall be duly considered for each construction/ erection activity. Moreover, only the persons who are trained in the respective trade shall be employed for executing that particular work.



PART B - LOADS AND LOAD COMBINATIONS

1.0 GENERAL

All structures shall be designed for the most critical combinations of dead loads, imposed loads, equipment loads, crane loads, steam piping (static & dynamic) and other piping loads, wind loads, seismic loads, temperature loads, forces developed due to differential settlement and any other loading conditions which can occur during the design life of the facility.

2.0 DEAD LOADS

2.1 Dead loads consist of the weights of the complete structure with finishes, fixtures, partitions, wall panels and all equipment of semi-permanent nature including tanks, partitions, roofing, piping, cable trays, bus ducts etc. The content of tanks shall be measured at full capacity for this purpose.

2.2 The piping loads, cable tray loads and the contents of the tanks, silos, bins and hoppers shall be listed separately so that they can be excluded from dead load when dead loads are acting as stabilising load for uplift.

2.3 Loads given in IS:875 (part-I) shall be made use of .

3.0 IMPOSED LOADS

3.1 Imposed loads in different areas shall include live loads, dust loads, minor equipment loads, cable trays, small pipe racks / hangers, erection loads, operation/ maintenance loads, etc. The loads considered shall not be less than that specified in IS:875 (Part II). Special use areas shall be investigated and loads revised upward as necessary. Floors and supporting members which may be subjected to heavy equipment live loads shall be designed on the basis of the weight of equipment or specifically defined live loads, whichever is greater

3.2 Culverts and allied structures including RCC pipes shall be designed for Class “ÄA” loading and checked for Class “A” loading as per IRC standards for two lane road and above.

3.3 Covers for trenches & channels, which are not exposed to vehicular traffic, shall be designed for live load of adjoining area or 1.5 t/sqm whichever is higher. Where channels are likely to be exposed to vehicular traffic, the requirements of code of practice for road bridges shall be adhered to

3.4 Piping anchor and restraint forces of major piping shall be obtained from

piping analysis results and shall be considered as live load in the structure design.

3.5 Ponding effects due to framing deflections for roofs, if any shall be considered.

3.6 In addition to the live loads, a minimum of 0.50 kN/sqm shall be considered as Hung loads for electrical, ventilation & air conditioning. Load of 1.0 kN/sqm shall be considered as Hung loads for piping unless otherwise mentioned.

3.7 Live load reduction shall be in accordance with the provisions of IS:875 and IS:1893 in case of seismic analysis.




4.0 EARTH PRESSURE LOADS

4.1 Earth pressure for all underground structures , cold water basin of cooling tower and under ground liquid storage tanks etc shall be calculated using coefficients of earth pressure at rest.

4.2 In addition to earth pressure and ground water pressure, etc. a minimum surcharge load of 1.5 t/sqm shall also be considered for the design of all underground structures including channels, sumps, cable and pipe trenches, etc. to take into account the vehicular traffic in the vicinity of the structure.

5.0 WIND LOAD

5.1 Wind load on structures shall be calculated as per provisions of IS:875 (part 3). The wind shall be assumed to blow in any direction and most unfavourable condition shall be considered for design.

5.3 In design of structures, wind force on equipments supported on frame including all fixtures, piping, staircases, ladders, handrails, etc. shall also be considered.

6.0 SEISMIC LOADS

6.1 Seismic analysis shall be carried out as per the latest edition of IS: 1893 (Part 1 & 4).

6.2 The Structures shall be classified into four categories as per Table 5 of IS: 1893 (Part 4)

6.3 Importance factor for each structure shall be as per Table 2 of IS: 1893 (Part 4).

6.4 Method of analysis for each structure shall be decided as per clause 10.3 IS: 1893 (Part 4), which depends on the seismic zone & category of the structure.

6.5 Response Reduction factor shall be as per Table 3 of IS: 1893 (Part 4).



PART B - LOADS AND LOAD COMBINATIONS SECTION: D4.6b

7.0 TEMPERATURE LOAD

7.1 Expansion and contraction due to changes of temperatures of materials of a structure shall be considered and adequate provisions shall be made for the effects produced (as per provision in relevant IS codes). Suitable expansion joints shall be provided in the longitudinal direction wherever necessary with provision of twin columns. The maximum distance of the expansion joint shall be as per the provisions of IS:800 and IS:456 for steel and concrete structures respectively.

7.2 Analysis shall be carried out for ambient temperature variation. The temperature variation shall be considered as 2/3 of average maximum annual variation in temperature. The average maximum annual variation in temperature for this purpose shall be taken as the difference between the mean of the daily minimum temperature during the coldest month of the year and mean of daily maximum temperature during the hottest month of the year. The structure shall be designed to withstand thermal stresses due to 50% of the temperature variation.

7.3 Coefficient of thermal expansion of steel shall be taken as per IS:800. Coefficient of thermal expansion for concrete shall be taken as per IS:456

8.0 EQUIPMENT LOADS

8.1 Static and dynamic loads of major equipments such as deaerator, feed water tanks, BFP, motors, fans, monorails, cable load, pipeload, tanks etc. shall be based on the manufacturer’s data of the specified equipments and shall be considered in design in addition to the live load. However, where the uniform floor live load adequately accounts for the equipment moving weight, the weight of such equipment as a dead load shall not be considered e.g. switchgear and control room floors are usually designed for a live load that includes the equipment weight.

8.2 All equipments, tanks and piping design loading shall include hydraulic test loading. Weight of equipments, ducts, tanks, pipes, conduits, etc. supported by structure shall include maximum possible loading conditions i.e. flooded conditions and associated impacts, test loading, anchorages and constraint effects.

8.3 Air and gas duct loads shall include weight of insulation, duct attachments, dust accumulation loads, seismic, wind and other loads applicable




SECTION: D4.6b

9.0 CRANE, MONORAIL & ELEVATOR LOADS

9.1 Crane girders and supporting columns shall be designed for vertical and horizontal forces (including impact forces) as per crane vendor’s data. All lifting beams and monorails shall have their design loads increased for impact factor as mentioned hereinafter.

9.2 Impact Factor

Loads for cranes, hoists and elevators shall be taken as per IS:875. The minimum impact factor to be used in design shall be as follows:

9.2.1 Crane Loads

a) For vertical force, an impact factor of 25% of the maximum crane wheel load.

b) A lateral crane surge of 10% of the weight of the trolley plus lifted load applied at the top of each rail divided in proportion to the relative lateral stiffness of the rail support system.

c) A horizontal surge of 5% of the maximum static wheel loads of the crane applied at the top of the rail in the longitudinal direction.

d) In case two cranes are provided and tandem operation is not envisaged, the load shall be taken as one crane fully loaded and second crane without lifted load but standing idle adjacent to first crane.

e) In case more than one crane is provided and tandem operation is envisaged for some bays, then the load shall be taken as both the cranes fully loaded and standing side by side for these bays. For other bays, load shall be taken as one crane fully loaded and second crane without lifted load but standing idle adjacent to first crane.

9.2.2 Monorail Loads




SECTION: D4.6b

a) Impact factor of 10% of lifted load of hoist for monorail and support design

b) Impact factor of 25% of the lifted load for electrical pulley and support design.

9.2.3 Elevator

100% of the lifted load including elevator live load plus the cab weight for the elevator support beams.

9.2.4 Pedestals supporting gravity take ups for conveyors and pedestals in elevator pits shall be designed assuming 100% impact factor.

10.0 OTHER LOADS

10.1 Stresses imparted to structures due to differential settlements, variation of water table, erection and maintenance loads, creep and shrinkage shall also be considered in design of all structures.

10.2 In order to allow for unusual loading during steel member erection or during the construction period, all beams on major column lines acting as column struts or ties shall be designed to withstand an axial force of 45t in combination with the dead load of the beam. End connections on these beams are designed to transfer its axial load. Minimum of 12mm thick connection angle shall be provided unless thicker angles are required by design.

10.3 Roof girders / trusses in the service / maintenance bay of Turbine building shall be designed for crane erection loads.

10.4 Columns in turbine building near transformer yard shall also be designed to support tension due to strung conductors and shield wire, if the conductors are connected to the Turbine building columns.

10.5 For under ground structures, design shall also be checked against buoyancy due to the ground water (till ground level) during construction as well as after construction stages. Minimum factor of safety against buoyancy shall be ensured considering empty condition inside and ignoring the superimposed loadings. Provision of pressure relief valves/ flap valves, etc., shall not be permitted to counter the buoyancy in pump sumps.

10.6 Dispersion of load in any direction through soil shall be as per IS: 8009 (relevant part).

10.7 Dispersion of load through concrete shall be considered at an angle of 45 degrees with horizontal from the edge of contact area.

11.0 BASIC LOAD CASES




The following basic load cases shall be considered for the analysis:

i) Dead load : D

ii) Self Weight of permanent equipment : EL

iii) Live load on floor/walkway : L

iv) Live load on roof : LR

v) Crane load with lift : CR1

vi) Crane load without lift : CR2

vii) Wind load : WL

viii) Seismic load : SL

ix) Load due to soil pressure : SP

x) Load due to surcharge : SCL

xi) Load due to hydrostatic pressure : HP

xii) Load due to temperature : TL

xiii) Special loads : SPL

12.0 LOAD COMBINATIONS

12.1 The individual members of the frame shall be designed for worst combination of forces such as bending moment, axial force, shear force and torsion. Permissible stresses for different load combinations shall be taken as per IS:875 (Part-V) and other relevant IS codes. Wind and seismic forces shall not be considered to act simultaneously.

12.2 Criticality of erection / maintenance loads shall also be checked separately in combination with other simultaneously occurring loads for possible design loading.

12.3 For design of main plant structures during seismic conditions, the deareator feed water tank shall be considered full, up to operating level. However for other load combinations flooded condition shall be assumed.

12.4 “Lifted load” of crane shall not be considered during seismic condition.

13.0 LOAD COMBINATIONS FOR UNDERGROUND STRUCTURES




Following loading conditions shall be considered in addition to the loading from super structure for the design of sub structure of pump house, channels, sumps, tanks, reservoirs, trenches and other under ground structures.

13.1 Only liquid pressure from inside and no earth pressure and ground water pressure and surcharge pressure from outside (applicable only to the structures which are liable to be filled with water or any other liquid).

13.2 Earth pressure, surcharge pressure and ground water pressure from outside and no water pressure from inside.

13.3 Base slab of the pump house shall be designed for the condition of different combinations of pump sumps being empty during maintenance stages with maximum ground water table. Intermediate dividing piers of pump sumps and partition walls in channel shall be designed considering water on one side only and the other side being empty for maintenance.

13.4 Design shall also be checked against buoyancy due to ground water during construction and operation stage. Minimum factor of safety as per IS:3370 against buoyancy shall be ensured considering empty condition ignoring superimposed loads.

14.0 SPECIAL STRUCTURES

For the following structures additional loading criteria as mentioned below in addition to the criteria discussed above:

14.1 Switchyard Structures

14.1.1 The loading for the design of switchyard structures shall be as per IS: 802 Part 1/Sec 1:1995 (latest edition). Following loads shall be considered:

a) Dead load due to equipment and structure.

b) Wind load on towers, conductors, ground wires and insulator strings calculated as per Clause 8 and 9 of IS: 802.

c) Temperature effects consisting of effect of temperature variation and sag tension as per clause 10 of IS:802.

d) Climatic loads as per clause 11.2 of IS:802.

e) Anti cascading loads as per clause 11.3.1 of IS:802.

f) Torsional and longitudinal loads caused by breakage of conductor as per clause 11.3.2 and 16 of IS:802.

g) Construction and maintenance loads




h) Seismic loads as per IS:1893. SECTION: D4.6b

i) Short circuit forces including “snap effect” in the case of bundled conductors.

14.1.2 Switchyard structure shall be designed for the worst combination of above loads. The factor of safety for design of members shall be considered as 2 for normal & broken wire conditions and 1.5 for combined short circuit and broken wire conditions. Short circuit forces and wind forces shall not be considered simultaneously.

14.3.3 Foundation shall be designed for a factor of safety 2.2 for normal and broken wire condition and 1.65 for combined short circuit and broken wire conditions. Design of foundation shall be carried out as per IS: 4091.

14.2 HRSG Support Structures

14.2.1 The supporting structure shall be designed for the following :

(a) Live / imposed loads

(b) Dead loads

(c) Static and dynamic loads of piping, movable equipment and maintenance parts

(d) Cantilever loads of not less than 500 kg/m at a distance of 1200

mm from the external face or the columns, on both sides of the HRSG, for cable trays and walkways.

(e) Seismic or wind loads as specified elsewhere in the specification

(f) Temperature variation of ± 25 deg. C for atmospheric temperature variations

(g) Temperature variations under HRSG operating conditions

(h) The loads listed above indicate the minimum requirements 14.2.2 HRSG supporting structures shall be so configured that the temperature

of steel does not exceed 60 deg.C unless specified otherwise. Brackets shall be provided on both sides of the outermost row of columns of the HRSG for supporting cable trays and walkways, at a height not exceeding 10 m. The exact levels shall however, be decided during detail engineering.

14.2.3 The bracings in the HRSG structure shall be provided such that under no circumstances normal / convenient access to all points in the boiler is blocked or obstructed.




14.2.4 HRSG support structures shall be checked for differential settlement of foundations which shall be restricted to 1 in 1000 of span or 8 mm whichever is less. 14.2.5 In design of HRSG support structures dynamic piping loads need not be considered acting simultaneously with wind or seismic loads. Increase in permissible stresses shall be allowed in load combinations where dynamic piping loads are considered and shall be as permitted under seismic load conditions. 14.2.6 Design criteria for foundations and some other facilities / areas are

covered separately in this specification.



SECTION: D4.6c PART C - REINFORCED CONCRETE STRUCTURES AND

FOUNDATION 1.0 REINFORCED CONCRETE STRUCTURES & FOUNDATIONS

All structures, building foundations, machines / equipment foundation, water retaining structures, trenches, pits, etc. shall be designed as per latest relevant IS codes in general. Construction in general shall follow provisions of IS: 456 and IS: 3370 for normal and water retaining structures respectively.

2.0 DESIGN METHODOLOGY

2.1 General

2.1.1 All designs of RCC structures shall be carried out by limit state method as per IS: 456 unless use of working stress method is specifically mentioned. Design strength of materials and design loads shall be calculated using appropriate partial safety factors over characteristic strength and characteristic loads as per IS: 456.

2.1.2 For reinforcement detailing IS:5525 and SP:34 shall be followed.

2.1.3 The walls shall be provided with reinforcement on both faces for sections 150 mm or more, even if not required from design consideration.

2.1.4 IS: 11384 shall be followed for design of steel concrete composite beam.

2.2 Foundation and Underground Structures

2.2.1 General

2.2.1.1 Type of foundation system, i.e. pile, isolated, strip, raft or piling shall be decided based on the loading arrangement, load intensity and soil strata. Design of foundations at various levels shall be dependent upon the soil bearing capacity/ pile capacity at that level.

2.2.1.2 Foundation system adopted shall ensure that settlement / relative settlement is as per provision of IS: 1904 and other Indian Standards. However, the settlement shall be restricted to a lower value, if necessary as per the system requirement.

2.2.1.2 All foundation including machine / equipment foundations shall be of RCC construction. All foundations shall be designed in accordance with relevant parts of the latest revisions of Indian standards IS: 2974 and IS: 456. Raft foundations shall be designed as per IS: 2950.

2.2.1.4 Analysis, design, concreting, construction methodology and driving of pile foundation shall be as per relevant parts of IS: 2911.

2.2.1.3 All underground pits, tunnels, basements, cable and pipe trenches, etc., shall be leak proof RCC structure where specified design depth of ground




FOUNDATION

water table so warrants. Effects of uplift and reduction in bearing capacity due to underground water table shall also be considered.

2.2.1.4 Details of subsoil conditions, average ground water table levels, foundation system recommendations for various buildings and equipment shall be based on final Geotechnical investigations to be carried by CONTRACTOR and final report.

2.2.1.5 For identifying the subsoil for founding purposes, the Bidder shall depute / post an experienced qualified geologist / geotechnical engineer so that the specified strata as conceived in the design is reached.

2.2.2 Liquid Retaining Structures

2.2.2.1 RCC water retaining structure like storage tanks, reservoirs, cooling tower basin, etc. shall be leak proof and designed as cracked section with limiting crack width to 0.1 mm in accordance with IS 456 by limit state method. Crack width shall be checked as per IS:456.

2.2.2.2 Water channels and substructure of pump houses shall be designed according to IS:456 with limiting crack width to 0.1 mm. Crack width shall be checked as per IS:456.

2.2.2.2.1 All water retaining / storage structures shall be designed assuming liquid upto the height of wall irrespective of provision of any over flow arrangement. No pressure relieving devices shall be permitted in underground structures.

2.2.2.3 In all liquid retaining structures, PVC water bar shall be provided at each construction / expansion joint. The sequence of construction shall also be specified on drawings showing construction joints.

2.3 Machine Foundations The design of machine / equipment foundation shall be as per IS:456 and IS:2974. The provisions of DIN 4024 shall also be followed for machine foundations.

2.3.1 All machine / equipment foundations and structures subject to vibrations shall be suitably proportioned so that amplitude and frequency of the foundation / structures are within permissible limits. 2.3.2 Analysis and design of the Gas Turbine-Generator (GTG) foundation shall be carried out in accordance with relevant codes DIN 4024 Part-1 and IS: 456 and/or manufacturer’s requirements. GTG foundation shall be considered as a flexible foundation (slab foundation as per Cl 2.7.4 of DIN 4024 Part-1). A static and dynamic analysis shall be carried out using finite element computer program using 3D solid or plate bending




FOUNDATION

elements. All the geometric and inertial characteristics of the foundations shall be taken into account. The characteristics of the soil (or improved soil) shall be modelled to represent the soil-structure interaction.

2.3.3 Analysis and design of the Steam Turbine-Generator (STG) foundation shall be carried out in accordance with relevant codes IS: 2974 Part-3 and IS: 456 and/or manufacturer’s requirements. Static and Dynamic analysis shall be carried out using finite element computer program using 3D beam/shell or 3D solid elements with columns fixed at top of mat level. 2.3.4 Natural frequencies and amplitude of vibrations of turbine generator foundations ( STG & GTG) shall be as per relevant applicable code of practices as indicated above and/or as per manufacturer’s requirements. For dynamic analysis, masses of stator and rotor shall be lumped at their respective CGs. Fundamental natural frequencies in all three directions shall be separated by at least 20% with respect to machine speed. Forced vibration analysis shall be performed at the operating speed and also at frequencies corresponding to certain selected modes (natural frequencies within 0.9 to 1.1 times the operating speed) using normal machine unbalance loads. Amplitudes calculated shall be ensured to be within the permissible limits as specified by the manufacturer. In the absence of specified criteria, amplitude shall be limited to alarm limit specified in ISO 10816-2. The exercise shall be repeated by releasing the rotor mass in the axial direction at each bearing location except at thrust bearing for STG foundation. 2.3.5 The loads to be considered for static analysis and design shall consist of dead weight of the machine and foundation, machine power torque, condenser loads under normal operating condition (for STG), thermal elongation forces , forces due to one sided operation of the condenser (for STG), forces due to condensate pump failure (for STG), vacuum loads (for STG), forces due to piping, frictional forces at machine sole plate level for turbine, generator and condenser, temperature distribution under operating condition, failure loads of turbine (blade unbalance/loss of blade/bowed rotor), failure loads of generator (short circuit loads), seismic loads due to generator, turbine and condenser and erection loads.

2.3.6 The turbine generator foundations shall also be designed to meet the manufacturer’s static deflection criteria.

2.3.7 All block type foundations resting on soil shall be designed using Barken’s method. These foundations shall be dimensioned in such a way that the mass of the foundation shall not be less than the three times the mass of the equipment and the CG of the combined mass of foundation & equipment should pass through the CG of the base area with tolerance not more than 5%. Dynamic analysis shall be carried out to calculate




FOUNDATION

natural frequency in all modes including coupled modes and to calculate vibration amplitudes. Frequency and amplitude criteria as laid down by the relevant codes or machine manufacturers shall be satisfied. In case frequency or amplitude criteria of IS: 2974 cannot be satisfied, vibration isolation system (VIS) with springs and viscous dampers shall be provided. Minimum reinforcement shall be governed by IS 2974 and IS 456.

2.3.8 For framed type foundations which support any major rotary equipment, the criteria specified in clause 2.3.4 & clause 2.3.5 for TG foundation shall be followed.

2.3.9 In the case of variable speed machines, one or more natural frequencies of the foundation may coincide with the operating frequency of the machine. If it is not possible to satisfy the codal frequency or amplitude criteria VIS with springs and viscous dampers shall be provided. It shall be ensured that not more than 5% of the dynamic loads are transmitted to the substructure. Necessary provisions of DIN 4024 shall be adhered to while designing the substructure. Substructure shall be designed for static loads. The vibration isolation system shall consist of helical spring units and viscous dampers supporting the RCC inertia block which support the machine. The spring units shall conform to DIN 2089 and DIN 2096.The static and dynamic analysis shall be carried out as specified in clause

2.3.4 & clause 2.3.5 above except that the analysis can be based on a plate model/Three dimensional solid finite element model. The frequency and amplitudes shall be checked as per relevant applicable code of practices or as per manufacturer’s requirements. The permissible amplitude of vibration shall be as specified by the manufacturer and shall be in “satisfactory” range as per VDI 2056, whichever is more stringent.

2.3.10 For the foundations supporting minor equipment weighing less than one ton or if the mass of the rotating parts is less than one hundredth of the mass of the foundation, no dynamic analysis is necessary. However, if such minor equipment is to be supported on building structures, floors, etc. suitable vibration isolation shall be provided by means of springs, neoprene pads, etc. and such vibration isolation system ( VIS) shall be designed suitably.

2.3.11 All such foundation shall be separated from adjoining part of building and other foundations. Joints at floor / slab shall be suitably sealed. All appendages to such foundations shall be reinforced suitable to ensure integral action.

2.3.12 The Vibration Isolation system supplied should be of proven make. The Contractor / their associates for the supply of this system should have designed spring supported machine foundations, manufactured , supplied and installed vibration isolation systems consisting of steel helical spring units (Conforming to DIN 2096 & DIN 2089) and viscous dampers




FOUNDATION

(Providing damping resistance in all three planes) for not less than 25 (twenty five) machine foundations of heavy rotating machine systems, such as Turbine generators, Boiler feed pumps, ID/ PA / SA fans etc., All the foundation systems be in successful operation (without replacement) for at least 3(three) years as on the date of bid opening.

2.4 Increase in Stresses

2.4.1 Where stresses due to wind (or seismic) and temperature are combined with those due to other loads, the allowable stresses in concrete and reinforcement steel shall be increased by 33.33% in case of working stress design.

2.4.2 Bearing capacity of the soil shall be allowed to increase by 25% under seismic/ wind load condition.

2.4.3 Permissible stresses for different load combinations shall be taken as per relevant IS codes.

3.0 STABILITY OF STRUCTURES

3.1 Design shall be checked against buoyancy due to the ground water during construction and maintenance stages for structures like under ground storage tanks, pits, trenches, basements, etc. Minimum factor of safety of 1.2 against buoyancy shall be ensured considering empty condition inside and ignoring the superimposed loading. For purpose of calculating downward load due to any overburden, only the mass located vertically above the projected area of the base slab shall be taken in to consideration.

3.2 All building sub-structures including pump houses shall be checked for sliding and overturning stability during both construction and operating conditions for various combination of loads. Factor of safety for these cases shall be taken as mentioned in IS: 456 and other latest relevant IS codes. However following minimum factor of safety shall be followed:

a) Factor of safety against overturning due to wind, seismic or other lateral load shall be 1.5 minimum

b) Factor of safety against sliding shall be 1.5 minimum

c) Factor of safety against uplift due to hydrostatic forces shall be 1.2 and due to any other loads shall be 1.5.

3.3 Stability of the structure shall also be investigated for loading conditions during construction, repair or other temporary measures. Lower factor of safety may be used for such loading conditions as per relevant IS codes.




FOUNDATION

3.4 In cases where dead load provides the restoring force, only 0.90 times characteristic dead load shall be considered. Imposed loads shall not be considered as restoring force.

4.0 MIN. THICKNESS OF CONCRETE STRUCTURAL ELEMENTS

4.1 The following minimum thickness shall be followed:

a) Suspended floor / slab / walkways /canopy slabs, etc. : 125mm

b) Ground floor slab (non-suspended) : 150mm

c) Water Retaining slabs / walls : 200mm

d) Cable/pipe trenches/underground pits/ : 125mm

Launder walls and base slab

e) All footings (including raft foundations) : 300mm

f) Parapets : 125mm

g) Sunshades : 75mm at edge

h) precast louvers / fins : 50mm

i) Precast trench cover slabs / floor slabs / louvers : 75mm

l) Basement walls and base slab : 200mm

k) Pile caps : 300mm

l) Underground reservoir

Below ground water table : 200mm

Above ground water table : 150mm

4.2 From fire resistance point of view minimum thickness of reinforced concrete members shall be as per fig.1 of IS: 456. Minimum fire rating of 2 hours shall be considered where fire hazard is expected.

5.0 MINIMUM HEIGHTS FOR PEDESTALS OF STEEL COLUMNS

5.1 Pedestals to Steel Columns for building structures shall be:

Top of RCC foundations (pedestals) shall normally be kept at a lower level so that the column base plates together with gussets and stiffeners remain below finished floor level (FFL) unless specified otherwise. Foundation



SECTION: D4.6c

PART C - REINFORCED CONCRETE STRUCTURES AND FOUNDATION

levels for columns shall be decided to accommodate underground services, pits, trenches, etc.

5.2 Stair and ladder pedestal shall be kept 200 mm above the finished floor level.

5.3 Pedestals to Steel Columns for Equipment structures:

a) Equipment in open area : as required (300mm min)

b) Equipment in covered area : as required (150mm min)

c) Structures and equipment : as per vendor’s data subject to

supplied by vendor minimum as specified above.

6.0 MINIMUM HEIGHTS FOR ENCASEMENT OF STEEL COLUMNS

In case the top of pedestal is kept at a lower level so that the column base plate together with gussets and stiffeners remain below finished floor level (FFL) the column bases as well as the column sections shall be encased in concrete above FFL as per following:

a) Open area : 300mm above paved level

b) Covered area : 150mm above FFL

7.0 CONCRETE MIX The following minimum grades of concrete as per IS: 456 shall generally be used for the type of structures noted against each grade. Ordinary Portland Cement (OPC) shall be used except for under ground structures wherein sulphate-resisting cement shall be used. Grade of cement shall be minimum 43 grade or 53 grade as per IS. For super structure of cooling towers richer mix many be used as per the design requirement. However requirement of table 4 & 5 of IS 456 shall be satisfied depending on the exposure condition. The environmental exposure condition of “Severe” shall be considered for all design condition.



SECTION: D4.6c


a) Mix (1:5:10) Fill concrete

Foundation below brick wall, blinding layer b) Mix (1:4:8) below foundations, trenches and

underground structures, minimum thickness of the layer shall be 75 mm.

c) Grade M20 Base plate encasement, pavement around building including plinth protection work, encasement of structural steel work.

d) Grade M30 All other RCC members except where other grades are specified as above

Intermixing of different grades of concrete in the same structure shall not be allowed in a particular structural element.

The minimum cement content shall be governed by the requirement of IS 456 for normal concrete structure and IS 2911 for piles.

However higher grade of concrete may also be used than the minimum specified to satisfy the design requirement for TG foundations, BFP Foundations, under ground structures etc.

The minimum water cement ration shall be as per IS 456

Clear cover to reinforcement shall be for 2-hour fire rating as per IS 456.

8.0 REINFORCEMENTS

8.1 Reinforcement bars shall be as per the following codes:

High Yield Strength Deformed bars : IS:1786

Mild steel bars : Grade I of IS:432

Welded wire fabric : IS:1566

8.2 CONTRACTOR shall supply to the Owner copies of all manufacturer’s test certificates for reinforcement bar delivered to site. The certificate shall show the results of tests necessary to prove that the reinforcement complies in respects with the relevant Indian Standards.

8.3 All reinforcement shall be free of all loose mill scale and thoroughly cleaned to remove all loose rust, oil, grease or other harmful matter.

8.4 Bars shall not be bent or straightened in a manner that will damage the bar Reinforcement shall be bent cold.




FOUNDATION

8.5 All reinforcement shall be accurately fixed by approved means and maintained in correct position as shown in the drawings by use of blocks, spacers and chairs as per IS 2502 to prevent displacement during placing and compaction of concrete.

8.6 No metal part of any device shall be used for connecting bars or for maintaining reinforcement in the correct position with in the specified minimum concrete cover to the reinforcement.

8.7 Welding of reinforcement shall not be carried out without the permission of the Owner.

8.8 Projecting reinforcement or dowel bars for future connection of the structural works shall be protected by cement paint, if they are to be left exposed for a long time.

8.9 All the reinforcement bars used shall be of fusion bond epoxy coating as per IS 13620.

8.10 Reinforcement detailing shall be as per IS 13920, SP 34.

8.11 Two layers of reinforcement (on both inner and outer faces) shall be provided for RCC wall sections having thickness 150 mm or more.

9.0 GROUTING

9.1 Non-shrink flowable grout shall be used for under pinning work below base plate of columns. Non-shrink cum plasticiser admixture shall be added in the grout. For grouting of base of machine foundation high strength ready mixed non-shrink flowable grout shall be used.

9.2 Type and grade of grouting for structural columns and equipment bases shall be indicated. Crushing strength of the grout shall generally be one grade higher than the base concrete. Minimum grade of grout shall be M

30.

9.3 Nominal thickness of grouting shall be at least 50mm for building columns and pedestals of major equipment. For secondary posts, stair and ladder base, etc. grouting shall not be less than 25mm thick.

10.0 MINIMUM COVER TO FOUNDATION BOLTS

Minimum distance from the centre line of foundation / anchor bolt to edge of pedestal shall be the maximum of the following:

a) Clear distance from the edge of base plate / base frames to the outer edge of the pedestal shall be minimum 50mm.




FOUNDATION

b) Clear distance from the face of pocket to the outer edge of pedestal shall be 75mm.

c) Clear distance from the edge of sleeve or anchor plate to the edge of pedestal shall be 75mm.

11.0 MISCE LLANEOUS REQUIREMENT

11.1 Fillets at the junction of roof and vertical walls shall be provided with cast in situ cement concrete 1:2:4 (nominal mix) followed by 12mm thick 1:4 cement mortar.

11.2 A screed layer not less than 100 mm thick of cast in situ concrete of nominal mix 1:3:6 shall be provided below all water retaining structures. A sliding layer of craft paper or bitumen paper shall be provided over the screed layer to destroy the bond between screed and base slab.

11.3 All under ground structures such as CW sumps etc. shall be designed as per IS: 456 but limiting the crack width to 0.1 mm for the external surfaces. Check for crack width shall be in accordance with IS: 456. In case of leakage in the above structures injection grouting method shall be applied to repair the structure according to the requirement of IS: 6494.

11.4 For switchyard foundations anchor bolt with mechanical anchorage shall be provided along with foundation concrete. Bolts in pocket shall not be

adopted. Foundation for all switchyard towers shall be designed on per IS: 4091. Contact between foundation and the soil strata shall be ensured for all conditions and combinations of loading.

11.5 Plywood formwork shall be used for all water retaining / conveying structures and for all over ground concrete works. For other areas steel / plywood formwork shall be used.

11.6 Unless specified 20 mm and down graded aggregates shall be used for all structural concrete works. However 40 mm and down graded aggregates may also be used under special conditions for foundation. with prior approval from OWNER.

11.7 Tolerance for formed and concrete dimension shall be as per IS:456.

12.0 MAJOR EQUIPMENT FOUNDATIONS

Special requirements for concreting of major equipment foundations shall be as given below:

12.1 Coarse Aggregates

12.1.1 Sound and durable crushed stone aggregates shall be used. All aggregates shall be tested for alkali aggregate reaction. Materials, which




FOUNDATION

contain high percentage of reactive silica, shall not be used. In exceptional cases of high percentage of reactive silica content, aggregate may be allowed where low alkali cement shall be used. Lime stone aggregate shall not generally be used as an aggregate for foundations, which are subjected to high temperature and repeated temperature cycles (like in the case of all machine foundations).

12.1.2 The course and fine aggregate shall be naturally occurring sand gravel or stone, crushed or uncrushed. They shall be obtained from an approved source and shall be hard, strong, durable, clear and shall not contain any harmful material not to affect adversely the concrete quality.

12.1.3 Only coarse and fine aggregates from the approved quarries and conforming to IS: 383 shall be used on the work.

12.2 Temperature Control of Concrete

The temperature of fresh concrete shall not exceed 230 C when placed. For maintaining the temperature of 230 C in the top deck of machine foundations, crushed ice shall be used in mixing water.

12.3 Admixture

Plasticizer cum retarder type admixture shall generally be added to the concrete for promoting workability in addition to retarding setting time for mass concreting work. The slump of concrete shall generally be in the range given below:

GTG/STG Foundations : 150mm to 200mm

BFP : 100mm to 150mm

Block foundation : 100mm to 150mm

Column : 100mm to 150mm

12.4 Form work

12.4.1 No metal part of any device for maintaining formwork in the correct location shall remain permanently within the specified concrete cover to the reinforcement.

12.4.2 In watertight construction, methods of fixing formwork, which result in holes through the concrete section when the formwork is removed, shall not be used. All wall ties shall have water baffles and wall kickers shall be cast monolithically with the base slab.

12.4.3 Approval for the size, type and position of any holes, insert or fixing required by CONTRACTOR shall be obtained before work proceeds.



SECTION: D4.6c

PART C - REINFORCED CONCRETE STRUCTURES AND

FOUNDATION

Unless otherwise specified or approved all holes shall be formed and all inserts cast in at the time of pouring No part of the concrete works shall be drilled or cut away without approval.

12.4.4 Formwork panels shall be stiff enough to prevent damage to the concrete surface caused by excessive movements of the panel during vibration of the concrete.

12.4.5 Damaged and used formwork shall not be re used without repairing.

12.4.6 All joints in form work and joints between the form works shall be sufficiently tight to prevent loss of liquid from the concrete through these joints.

12.4.7 The part of the ties shall be capable of being removed, so that no part remaining embedded in the concrete shall be nearer the surface of the concrete than the specified thickness of cover to the reinforcement. Holes left after the removal of ties shall be filled with concrete or mortar of approved composition.

12.4.8 Formwork props shall be positioned between permanent supports so that all members are supported at not more than 3 meters centre in both directions.

12.4.9 The props shall be in the form of space frames, composite or single members with sufficient stiffness or bracing so that props will neither sway nor buckle under loads which they are designed to carry.

12.4.10 The formwork or the false work shall not be removed from a structural component until CONTRACTOR ensure that the concrete has attained sufficient strength.

12.4.11 The concrete is to be regarded as sufficiently hardened when the component has attained such strength that it can resist all loads acting at the time of removal of the formwork.

12.4.12 Particular care shall be taken with components which have to carry virtually the full design load directly upon removal of the false work (e.g. in the case of roofs, or floor slabs which have to support loading from floors above them which have not yet hardened)

12.4.13 Props shall remain in position for as long a period a possible, particularly for structural components, which are subjected to a major proportion of their design loading as soon as the formwork has been removed.

12.4.14 No superimposed load shall be allowed on any part of the concrete work prior to the removal of the forms and props.




FOUNDATION

12.4.15 Film faced plywood formwork shall be used for the top decks of all machine foundations.

12.4.16 Scheme for Concreting

Weigh batching plants shall be mobilized for all machine foundations. Concrete pump shall be mobilized for GTG/STG foundations, BFP foundations. Arrangements for stand-by Plant and Equipments shall also be made.

12.5 Placing of Concrete

12.5.1 Before each concreting CONTRACTOR shall give sufficient notice to the Owner as directed such that an inspection will be made before the concreting.

12.5.2 The concrete shall be mixed in the mixer of adequate capacity having a power elevated loading hopper. The mixer shall be equipped with an automatic water-measuring tank filled with a device for locking the discharge setting. The Mixing shall continue until there is a uniform distribution of the materials and the mass is uniform in colour and consistency.

12.5.3 Any concrete surplus to immediate requirements shall be thrown away. In no case circumstances may the surplus be used later.

12.5.4 The volume of mixed materials in each batch shall comply with the mixer manufacturer’s written recommendations.

12.5.5 Concrete shall be transported as quickly as possible from the mixer to its final position without segregation or loss of any of the ingredients.

12.5.6 All equipment to be used for transporting material shall be kept clean; all containers used for transporting concrete shall be thoroughly washed out whenever mixing ceases.

12.5.7 Concrete shall be placed continuously up to construction joints while it is still sufficiently plastic for adequate compaction.

12.5.8 At all times when reinforced concrete is being placed a competent steel fitter shall be in continuous attendance. CONTRACTOR shall adjust and correct the position of any reinforcement, which may be displaced.

12.5.9 CONTRACTOR shall keep on site a complete record of the works showing the time and date when concrete is placed in each part of the work.

12.5.10 Concrete shall be thoroughly compacted by suitable mechanical vibrators during placing and shall be carefully worked around all reinforcement and embedded fixtures and in to the side and corners of the formwork.



SECTION: D4.6c


12.5.11 For top surfaces of slab and other surfaces for which formwork is not provided a smooth finish shall be provided with a wooden float after compaction.

12.5.12 Whenever, concrete is being vibrated at least one spare vibrator of each type in use shall be available in case of breakdown.

12.5.13 Compaction shall start as soon as there is sufficient concrete within the formwork to immerse the vibrator an vibration shall continue during the placing operation so that at no time shall there be a large volume of un compacted concrete in the form work.

12.5.14 The concrete shall not be placed directly against a vertical form face but shall be placed to flow to this surface during the compaction process. Care shall be taken to avoid the form face being splashed with mortar during the placing operation.

12.5.15 Exposed surfaces, immediately after final set, shall be protected from the sun. All concrete shall be well watered after it has been set and shall be kept continuously damp until thoroughly cured. Provision shall be made for adequate water distribution to all parts of the work so that if required this treatment can be continued sufficiently throughout the whole period of construction. In order to to keep the concrete continuously damp, all exposed surface shall be covered with continuously damped gunny bags or shall have water compounded on them, for full period of curing.

12.5.16 On exposed concrete surfaces in high sun temperatures and /or strong drying wind conditions CONTRACTOR shall use curing method, which also shields the concrete, and this shall be placed in position not later than half an hour after final tamping. Base mat as well as top deck of machine Foundations shall be cast in a single pour.

12.6 Ultrasonic Testing

Ultrasonic pulse velocity test shall be carried out for the top deck of all machine foundations and TG substructure to ascertain the homogeneity and integrity of concrete. In addition, additional cubes (at the rate of one cube per 150 cum of concrete subject to a minimum of six cubes) shall be taken to carry out Ultrasonic Pulse velocity (UPV) testing on the cubes to serve as reference UPV values. Testing shall be done as per IS: 13311 (Part-1). In case of any defects, the CONTRACTOR shall rectify the defects suitably using cement / epoxy grout etc.



SECTION: D4.6d PART D - STEEL STRUCTURES

1.0 GENERAL

1.1 Design of structural steel work shall include generally but not be limited to the steel constructions listed below :

i) Steel building structure and open structure

This shall include beams, columns, bracings, supporting structures for floors, roof slabs, cladding etc.

ii) Crane, gantry girder, monorails etc. iii) Large diameter storage tanks iv) Cooling Water Conduits v) Steel stack vi) Galvanised latticed structures for switchyard vii) Pipe and cable racks viii) Platforms and walkways ix) Ladders, staircases, handrails etc.

2.0 FRAMING

2.1 All steel framed structures shall be either “rigid frame“ or “simple space frames“ or a combination of the two.

2.1.1 Lateral forces shall be resisted by stiff jointed moment connections in rigid frame design. The column bases shall generally be fixed to concrete foundation pedestal by providing moment resistant base detail. 2.1.2 Simple space frame design utilises single-span beam systems, vertical diagonal bracing at main column lines and horizontal bracing at the roof and major floor levels. Most of steel buildings shall be designed as simple space frame structures. 2.2 The STG/GTG building design shall be a combination of rigid frame in transverse direction and simple frame in longitudinal direction.

2.3 Pipe rack shall consist of rigid main frame in transverse direction spaced longitudinally as required. In longitudinal direction, pipe rack shall be divided into sections of suitable length with an anchor bay. The main transverse frames shall be connected with longitudinal beams, which will transmit horizontal forces to braced anchor bays. The pipe and cable rack bridge structure shall be adequately rigid to carry the forces from pipelines at anchor points without undue deflection so that pipelines are really anchored at the anchor points. 2.4 Concrete floors shall be considered to provide continuous lateral support to the top (compression) flange of the support beams. However where large cut outs are provided in the floor slabs horizontal floor bracing shall be provided. Grating / chequered plate floor shall neither be considered to provide lateral support to the top flange of supporting beams nor to provide




a shear diaphragm. Adequate lateral support and horizontal bracing shall be provided as required in such cases.

2.5 Floors for vibrating machines of all kind together with supporting framework shall be adequately braced in both horizontal and vertical planes. Floors or structure supporting mechanical equipment shall be designed to minimise vibration, avoid resonance and maintain alignment and level. 2.6 Columns shall be designed to support the load combination, which produces the maximum interaction ratio. Exterior columns shall be designed to resist wind moments between braced elevation as appropriate. Columns shall also be designed to resist moments caused by discontinuous vertical bracing or non-concentric bracing work points. 3.0 MATERIALS

3.1 Structural steel shall conform to Grade A of IS: 2062 for rolled steel members or plates up to 20 mm thickness. For plates above 20 mm thickness or welded construction, steel conforming to Grade B (Killed) of IS: 2062 shall be used except for crane girders where Grade C (IS:2062) steel shall be used.

3.3 Chequered plates shall conform to IS:3502. All gratings shall be pressure locked type (preferably electro-forged) manufactured in accordance with applicable Indian Standard Codes. All chequered plates and gratings shall be galvanised. Pipes for handrail shall be as per medium grade of IS:1161 and shall be galvanised. Crane rails shall conform to IS:3443. 3.4 Materials used in flues shall be as per Clauses 6.37 of Section 6

4.0 CONNECTIONS 4.1 Welding shall be used for shop fabrication and joints. For site connections,

welding or high strength friction grip (HSFG) type bolts shall be used, except in few cases for shear connections of lighter members or removable beam connections where bolted joints may be adopted e.g. purlins, side girts etc. Minimum two bolts of diameter not less than 16 mm per connection shall be used.

4.2 IS:814, IS: 816 IS:1024, IS:4353 and IS: 9595 shall be followed for welding of structures.

4.3 For high strength friction grip bolt connections IS:4000 shall be followed.

High strength friction grip bolts shall be of property class 6.6 or 8.8 and shall conform to IS: 3757 and shall not be less than 20 mm in diameter unless designated otherwise. High strength bolts shall be installed as bearing type joint except where loads are reversible.

4.4 All bolted connections shall have bolts of minimum 16 mm diameter. The

connections of stairs and handrails shall be made with 20 mm diameter



SECTION: D4.6d

PART D - STEEL STRUCTURES

threaded fasteners conforming to IS:1363. Erection bolts shall be black bolts of minimum 12 mm diameter.

4.5 All bolts and nuts shall have property class compatible to each other. For bolts carrying dynamic or fluctuating loads and those in direct tension shall be provided with an additional double coil helical spring washer conforming to IS:6755. The threaded portion of the bolt shall project through the nut at least by one thread. 4.6 Where a steel beam or member is to be connected on RCC structure, it

shall be connected using an insert plate and preferably through shear connection.

4.7 For crane girders, welding between web and flange plates shall be carried out by submerged arc welding process. Full penetration of weld between web plate and top flange shall be ensured. Intermediate stiffeners shall be connected with top flange plate by full penetration butt weld. Welding across tension flange will not be permitted. Bearing edges of crane girders shall be machined.

4.8 The working point of the bracing connection shall be the centre of column and girder to which it connects. The connections of gusset plates to column and girders shall be made to include provisions for eccentricity in connection. The double angle back-to-back with gusset plate in between shall not be used in dust laden areas. Where double angles are not adequate, beam sections with web in the plane of bracing shall be used.

4.9 Horizontal bracings shall be of angle / tee section located at the bottom

of framing beams. Field welding of bracing at the underside of beam as required to meet slenderness requirement of bracing member shall be indicated on the drawings. Horizontal bracing shall be arranged to avoid framing into the beams at column locations.

4.10 For Major columns of main building, column splices shall be designed to resist the greater of the design axial tension load and moments or an axial tension load of 45 t plus 50% of the member capacity in bending in either major or minor axis, whichever produces the greatest number of bolts.

4.11 Minimum size of fillet weld shall be 5 mm. No intermittent weld is allowed.

4.12 Efficiency of site welds to be considered shall be as follows:

a) Butt weld above 25 m from ground --- 50% b) Others --- 80%

5.0 DESIGN METHODOLOGY




5.1 The Design of steel structures shall be done by working stress method, in accordance with the provisions of IS: 800 and other relevant IS codes as applicable to specific structures. 5.2 All buildings / structures shall be framed structure. Basic consideration for

structural framing shall be stability, rigidity, building usage, ease of fabrication / erection and overall economy. Additional bracings / moment connections shall be used to assure stability of structures. Structure shall be designed such that the surfaces of all parts shall be accessible for inspection, cleaning, painting and maintenance.

5.3 Crane gantry girders shall be single web plate girders of welded construction with bearing and intermediate stiffeners. Crane girder shall be designed as simply supported and of single span length. Chequered plate shall be used for gantry girder walkway flooring. For lifting / monorails beams ISMB sections shall be preferred and the bottom flange of all beams shall be checked separately for distortion and reinforced suitably if required. 5.4 Permissible stresses for different members shall not be allowed to exceed by 33.33% under wind and seismic conditions. However, members which are designed primarily to resist wind load such as bracing members, no increase in permissible stresses will be permitted. However, permissible stresses in bolts and welds shall be allowed to exceed up to 25 % only. 5.5 For design which requires the use of the minimum column load (such as, uplift on anchor bolts, column axial tension, etc.) the following criteria shall be used in determining minimum load. Use 90% of the column dead load, No live load is to be used, Uplift forces from vertical bracing are included where applicable and Wind uplift on the roof is included where applicable.

5.6 Base plates shall be placed on foundation pedestal with grouting. For large base plates necessary grout holes shall be provided. All anchor bolts for fastening steel columns on foundation shall be embedded in foundation during concreting itself. No anchor pockets in foundation shall be allowed.

6.0 PERMISSIBLE DEFLECTIONS

6.1 The permissible deflections of various steel members under normal loading conditions shall be as specified below. For calculation of deflections in structures and individual members dynamic effects shall not be considered, unless specified otherwise. Also, no increase in deflection limits shall be allowed when wind or seismic loads are acting concurrent with normal loading conditions.

6.1.1 Vertical Deflection:




a) For beams supporting dynamic equipment : Span / 500 b) For beams supporting floors / masonry : Span / 325 c) For beams supporting pipes (pipe racks) : Span / 400 d) For roofing and cladding components : Span / 250 e) For gratings and chequered plates : Span / 200

subject to a maximum of 6 mm

f) Coal conveyor gallery bridges : Span / 450 6.1.2 For crane gantries or any member subjected to working loads, the

maximum deflection under dead load and live load excluding impact shall not exceed the following values:

a) For manually operated cranes and monorails : Span / 500 b) For electric overhead cranes

i) up to 50 t capacity : Span / 750 ii) over 50 t capacity : Span / 1000

6.2 Horizontal deflections

The permissible horizontal deflections shall be as per following unless specified otherwise: a) Single storey building (without crane load) : Height / 325 b) Multistoried building (without crane load) : Height / 500 c) Pipe rack columns : Height / 200 d) Open Structures : Height / 200 e) Crane gantry girder due to surge : Span / 2000 limited

to maximum of 15 mm f) Building main columns at crane rail : Height / 2500 limited to

level due to action of crane surge load only maximum of 10 mm g) Open gantry columns at crane rail level : Height / 4000 limited to

due to action of crane surge load only maximum of 10 mm h) Coal handling trestles : Height / 1000

6.3 Provisions of IS: 800 and relevant latest IS Codes shall be followed for

limiting deflections of structural elements not listed above. 7.0 MINIMUM THICKNESS AND SIZES OF STEEL ELEMENTS 7.1 Minimum Thickness

The minimum thickness of various components of a structure and hot rolled sections shall be as follows. The minimum thickness of rolled shapes shall mean flange thickness regardless of web thickness. Structural steel members exposed to significantly corrosive environment shall be increased suitably in thickness or suitably protected otherwise as per good practice and sound engineering judgement in each instance. a) Trusses, purlins, girts and bracing : 6 mm b) Columns and beams : 8 mm c) Gussets : 8 mm




d) Stiffeners : 8 mm e) Base plates : 10 mm & above f) Chequered plates : 6mm o/p & above g) Grating flats : 5 mm h) Minimum thickness of structural members other than gratings and chequered plate directly exposed to weather and inaccessible for painting and maintenance shall be 8 mm.

7.2 Minimum Sizes

The flange width of purlins supporting light weight concrete slab shall not be less than 65 mm and for those supporting roof sheeting and wall cladding it shall not be less than 50 mm. Width of steel rolled section connected to other member shall be at least 50 mm. The depth of beams for platform of all structures shall not be less than 125 mm.

8.0 SLENDERNESS AND DEPTH RATIO

8.1 The slenderness ratio of main members in tension, compression or bending shall be in accordance with IS:800.

8.2 The following limiting ratios of depth to span shall be considered as a

general guide.

a) Truss 1 / 10 b) Rolled beams and girders for 1 / 24

Ordinary floors and rafters c) Supporting floor beams for vibrating 1 / 15

Machines / equipments d) Roof purlins and girts 1 / 45 e) Gable columns 1 / 30

9.0 FABRICATION AND ERECTION

9.1 CONTRACTOR shall prepare detailed fabrication drawings and erection scheme based on the design drawings approved by OWNER. Fabrication drawings are not to be submitted to OWNER for approval as the responsibility for correct detailing rests exclusively on the CONTRACTOR. However these drawings shall be furnished to OWNER for their reference to effect payment. Fabrication shall commence only on the basis of the fabrication drawings approved by the CONTRACTOR’S Consultant.

(a) Fabrication shall in general follow the provisions of IS:800, and good engineering practice where provisions of IS:800 are not clear. (b) Tolerance in fabricated steel work shall be as per IS: 7215. (c) Erection of fabricated steel components shall be as per erection drawings prepared by CONTRACTOR and approved by his CONSULTANT. (d) Tolerance for erected steel structures shall be as per IS:12843.




9.2 Inspection of Welding

The extent of quality control in respect of welds for structural elements shall be as follows.

9.3 Visual Examination

9.3.1 All welds shall be 100% visually inspected to check the following:

i) Presence of undercuts ii) Surface cracks in both welds and base metals. iii) Unfilled craters iv) Improper weld profile and size v) Excessive reinforcement in weld vi) Surface porosity

9.3.2 Before inspection, the surface of weld metal shall be cleaned of all slag, spatter matter, scales etc. by using wire brush or chisel.

9.4 Dye Penetration Test ( DPT) 9.4.1 This test shall be carried out for all important fillet welds and groove

welds to check the following: i) Surface cracks ii) Surface porosities

9.4.2 Dye Penetration Test shall be carried out in accordance with American National Standard ASTME165.

9.5 Ultrasonic test 9.5.1 Ultrasonic test shall be conducted for all groove welds and heat affected zone in dynamically loaded structures and for other important load bearing butt welds in statically loaded structures as desired by OWNER to detect the following:

i) Cracks ii) Lack of fusion iii) Slag inclusions iv) Gas porosity

9.5.2 Ultrasonic testing shall be carried out in accordance with American National Standard ANSI / AWS D1.1-92 Chapter 6 : Part C.




9.5.3 Before Ultrasonic test is carried out, any surface irregularity like undercuts, sharp ridges etc. shall be rectified. Material surface to be used for scanning by probes must allow free movement of probes. For this purpose, surface shall be prepared to make it suitable for carrying out ultrasonic examination. 9.6 Radiographic Testing (X - ray and Gamma - ray Examination)

9.6.1 This test shall be limited to 2% of length of welds for welds made by manual or semi-automatic welding and 1% of length of weld if made by automatic welding machines. The location and extent of weld to be tested by this method shall be decided by OWNER to detect the following defects:

i) gas porosity ii) slag inclusions iii) lack of penetration iv) lack of fusion v) cracks

9.6.2 Radiographic testing shall be conducted in accordance with AmericanNational Standard ANSI / AWSD1.1-92. 9.6.3 Any surface irregularity like undercuts, craters, pits, etc. shall be removed before conducting radiographic test. The length of weld to be tested shall not be more than 0.75 x focal distance. The width of the radiographic film shall be width of the welded joint plus 20 mm on either side of the weld. 9.7 CONTRACTOR shall provide testing equipment for conducting non-

destructive tests for confirming the integrity of welding wherever necessary as directed by the OWNER.

9.8 Acceptable Limits of Defects of Weld 9.8.1 Limits of Acceptability of welding defects shall be as follows.

i) Visual inspection and Dye Penetration Test The limits of acceptability of defects detected during visual inspection and Dye Penetration Test shall be in accordance with clauses 8.15.1 and clauses 9.25.3 of American National Standard ANSI / AWS D1.1-92 respectively, for statically and dynamically loaded structures.

ii) Ultrasonic Testing




The limits of acceptability of defects detected during ultrasonic testing shall be in accordance with clause 8.15.4 and clause 9.25.3 of American National Standard ANSI / AWS D1.1-92 respectively, for statically and dynamically loaded structures.

iii) Radiographic Testing:

The limits of acceptability of defects detected during Radiographic testing shall be in accordance with clause 8.15.3 and 9.25.2 of American National Standard ANSI / AWS D1.1-92 respectively for statically and dynamically loaded structures.

9.9 Rectification of Defects in Welds 9.9.1 In case of detection of defects in welds, the rectification of the same shall

be done as follows:

i) All craters in the weld and breaks in the weld run shall be thoroughly filled with weld

ii) Undercuts, beyond acceptable limits, shall be repaired with dressing so as to provide smooth transition of weld to parent metal. iii) Welds with cracks and also welds with incomplete penetration, porosity, slag inclusion etc. exceeding permissible limits shall be rectified by removing the length of weld at the location of such defects plus 10 mm from both ends of defective weld and shall be re-welded. Defective weld shall be removed by chipping hammer gouging torch or grinding wheel. Care shall be taken not to damage the adjacent material.

10.0 PAINTING

10.1 All steel structures shall receive two primer coats and two finish coats of painting. First coat of primer shall be given in shop after fabrication but before dispatch to erect at site after surface preparation as described below. The second coat of primer shall be applied after erection and final alignment of the erected structures. Two finish coats shall also be applied after erection.

10.2 Steel surface, which is to be painted, shall be cleaned of dust and grease and the heavier layers of rust shall be removed by chipping prior to actual surface preparation. The surface shall be cleaned to grade ST-2 as per SIS05-5900 or as per IS:1477 ( part -I). Surface preparation shall be done by means of sand blasting, which shall conform to IS Standard.

10.3 Primer coat shall consist of one coat of epoxy resin based zinc phosphate primer having minimum DFT of 100 microns.All paints shall be of approved brand and shade as per the OWNER’S requirement.




10.4 Intermediate coat (or under coat) shall consist of epoxy resin based paint pigmented with Titanium dioxide with min. DFT of 100 microns. 10.5 Top coat shall consist of one coat of epoxy paint suitably pigmented of approved shade and color with glossy finish and DFT of 75 microns. Additionally finishing coat of polyurethane of minimum DFT of 25 microns shall be provided. 10.6 The paint may be applied in one coat, in case high built paint is used,

otherwise two coats shall be applied.

10.7 Total DFT shall not be less than 300 microns.

10.8 Intermediate / top / finishing coat paints shall be form the same manufacture and the paints shall have compatibility with one another. Applications shall be as per manufactures recommendations.

10.8 All other steel members like doors, rolling shutters, pipe supports etc. shall be painted as per the details as above

10.9 Joints to be site welded shall have no paint applied within 100 mm of welding zone. Similarly where friction grip fasteners are to be used no painting shall be provided. On completion of the joint the surfaces shall receive the paint as specified. 10.10 Surfaces inaccessible after assembly shall receive two coats of primer prior to assembly. Surfaces inaccessible after erection including top surfaces of floor beams supporting gratings or chequered plate shall receive one additional coat of finish paint over and above number of coats specified before erection. Portion of steel member embedded / to be encased in concrete shall not be painted. 11.0 REQUIREMENTS FOR SPECIFIC STRUCTURES

11.1 Switchyard Structures

11.1.1 All switchyard structures comprising of towers, gantries, lightning masts, lighting towers, equipment structures etc. shall be galvanised steel with bolted site connection.

11.1.2 Three dimensional analysis shall be of carried out for structures like towers and gantries whereas two dimensional approach may be followed for equipment support structures.

11.1.3 All structural steel shall be of tested quality and shall conform to IS:2062. Steel tubes where used for equipment support structures shall conform to IS:1161.




11.1.4 All bolts and nuts shall be galvanised. In addition to heavy washers conforming to IS: 6610, spring washers conforming to IS:3063 shall be provided at all bolted connections. Bolts shall conform to IS:12427.

11.1.5 Fabrication and erection shall generally be as per IS:802 and IS:800;

wherever there is a contradiction between two codes the provision in IS:802 shall govern.

11.1.6 Galvanising 11.1.6 Galvanising of the towers shall be as per IS:4759 and IS: 2633 and as

given in the following paras. 11.1.6.1 Before galvanising, the steel shall be thoroughly cleaned of any paint, grease, rust, scale, acid or alkali or such other foreign matters as are likely to interfere with the galvanising process.

11.1.6.2 The acceptable values of the coating of zinc on the steel materials shall be in accordance with Table below:

KIND OF MATERIAL

Structural steel members except bolts,nuts and washers For bolts, nuts and washers

COATING

Average value Minimum value Over 750 gm/sq.m 610 gm/sq.m

Over 550 gm/sq.m 500 gm/sq.m

11.1.6.3 The galvanised surface shall consist of a continuous and uniformly thick

coating of zinc, firmly adhering to the surface of steel. The finished surface shall be clean and smooth, and shall be free from defects like discoloured patches, bare spots, globules, spiky deposits, blistered surface, flaking or peeling off, etc. The presence of any of these defects noticed on visual or microscopic inspection shall render the material liable to rejection.

11.1.6.4 There shall be no flaking or loosening when struck squarely with a chisel faced hammer. The galvanised steel member shall withstand minimum four number of one minute successive dips in copper sulphate solution as per IS:2633 unless specified otherwise.

11.1.6.5 All galvanised members shall be treated with sodium dichromate solution or an approved equivalent after galvanising, so as to prevent white storage stains.

11.1.6.6 Wherever galvanised bolts, nuts, washers, accessories, etc. are specified these shall be hot-dip galvanised. Spring washers shall be electro- galvanised. Readily available GI nuts, bolts and washers conforming to galvanising requirements may also be used.


Reliance Group 7 of 906


11.1.6.7 CONTRACTOR shall ensure that galvanising is not damaged in transit. In the event of occurrence of any damage, CONTRACTOR shall at his own cost adopt scrapping and regalvanising the member to satisfy the specific requirements.

11.2 STEEL CHIMNEY

11.2.1 The design and construction of chimney shall generally conform to IS:6533 and IS:800. Design and construction shall conform in every respect to Boiler and Factory Inspector’s regulations, as well as Civil aviation authorities requirements. The basic dimension of the chimney such as clear diameter, height etc. shall be decided based on the temperature, composition and quantity of flue gases, draft requirements, pollution control regulation etc.

11.2.2 The stack shall be designed to resist stresses due to the following loadings and load combinations as specified in clause 6.5 of IS:6533.

i) Self weight of the stack along with permanent fixture ii) Weight of lining iii) Wind loading - both static and dynamic as per IS:6533 and IS:875 iv) Earthquake load as per IS:1893 v) Effect of temperature. vi) A live load of 300 kg/sq.m on each platform.

11.2.3 Steel used shall be as per IS:2062 grade A for sections and plates less than 20 mm in thickness and IS:2062 grade B for thicker sections and plates. The stack shall be so designed that stresses do not exceed those maximum permissible stress as specified in IS:6533 modified to take into account temperature effect. 11.2.4 Minimum thickness of the stack shall be the calculated thickness obtained from stress and deflection consideration plus allowance for corrosion as per table 1 of IS:6533 considering design life as 20 years. Minimum thickness shall not be less than 6 mm. Maximum deflection of the stack due to static wind loading shall not exceed 1/200 of the unsupported height of the stack. 11.2.5 The base plates and holding down bolts shall be adequate to take the load, moments and reactions between the shell and foundations generally satisfying requirements of IS:800. Anchor bolt shall be made 3 mm larger in diameter than computed dimension to satisfy stress levels. Helical strakes shall be provided for the top 1/3 portion of the unsupported height as explained in clause A.2.2 of IS:6533.

11.2.6 Stability of the structure and foundations as a whole or any part of it shall be checked as per IS:6533.




11.1.6.7 CONTRACTOR shall ensure that galvanising is not damaged in transit. In the event of occurrence of any damage, CONTRACTOR shall at his own cost adopt scrapping and regalvanising the member to satisfy the specific requirements.

11.2 STEEL CHIMNEY

11.2.1 The design and construction of chimney shall generally conform to IS:6533 and IS:800. Design and construction shall conform in every respect to Boiler and Factory Inspector’s regulations, as well as Civil aviation authorities requirements. The basic dimension of the chimney such as clear diameter, height etc. shall be decided based on the temperature, composition and quantity of flue gases, draft requirements, pollution control regulation etc.

11.2.2 The stack shall be designed to resist stresses due to the following loadings and load combinations as specified in clause 6.5 of IS:6533.

i) Self weight of the stack along with permanent fixture ii) Weight of lining iii) Wind loading - both static and dynamic as per IS:6533 and IS:875 iv) Earthquake load as per IS:1893 v) Effect of temperature. vi) A live load of 300 kg/sq.m on each platform.

11.2.3 Steel used shall be as per IS:2062 grade A for sections and plates less than 20 mm in thickness and IS:2062 grade B for thicker sections and plates. The stack shall be so designed that stresses do not exceed those maximum permissible stress as specified in IS:6533 modified to take into account temperature effect. 11.2.4 Minimum thickness of the stack shall be the calculated thickness obtained from stress and deflection consideration plus allowance for corrosion as per table 1 of IS:6533 considering design life as 20 years. Minimum thickness shall not be less than 6 mm. Maximum deflection of the stack due to static wind loading shall not exceed 1/200 of the unsupported height of the stack. 11.2.5 The base plates and holding down bolts shall be adequate to take the load, moments and reactions between the shell and foundations generally satisfying requirements of IS:800. Anchor bolt shall be made 3 mm larger in diameter than computed dimension to satisfy stress levels. Helical strakes shall be provided for the top 1/3 portion of the unsupported height as explained in clause A.2.2 of IS:6533.

11.2.6 Stability of the structure and foundations as a whole or any part of it shall be checked as per IS:6533.




11.2.7 Upto a height of 2.5 m from the base, and at every platform level the Chimney shall be insulated externally with mineral wool.

11.2.8 Accessories shall be generally as per IS:6533. 11.2.9 Painting

11.2.9.1 Internal surface of the chimney shall be given two coats of heat resistant aluminium paint conforming to IS : 13183 over two coat of red oxide zinc chromate primer. External surfaces shall be given two coat of red oxide zinc chromate primer and one finish coat of heat resistant aluminium paint conforming to IS:13183 before erection. Top portion to a height of two times the diameter of the flue shall be given two coats of acid resistant paint conforming to IS:158 both inside and outside. Balance external surface shall be provided with two coats of synthetic enamel paint conforming IS:2932 with alternate bands of orange and white shades.

11.2.10 Construction Tolerance The difference between maximum and minimum internal diameter of the shell measured at any cross section shall not exceed 1% of the nominal diameter. After erection, the deviation of the stack from the vertical at any level shall not exceed 1/1000 of the height at that particular section.

11.3 Storage Tanks 11.3.1 Design, fabrication and erection of the cylindrical welded storage tank

shall follow the provisions of IS:803. The stresses in the tank shall be computed on the assumption that tank is filled with water. Tension in each course shall be computed at 30 cm above the centreline of lower horizontal joint of the course under consideration.

11.3.2 Wind and internal vacuum loads shall be considered together to check

the stability of tank. 11.3.3 Joint efficiency factor shall be taken as 0.85 for butt joints to determine the minimum thickness of shell plates provided all the vertical and horizontal butt welds are spot radiographed. Where welds are not inspected by radiography joint efficiency factor of 0.7 shall be used. However it is recommended that all butt welded joints shall be radiographed. 11.3.4 Minimum thickness of shell plate shall be as given in clause 6.3.3.2 of IS:803 to which corrosion allowance shall be added. Maximum thickness of shell plate shall not exceed 40 mm. Width of shell plate shall not be less than 1500 mm. 11.3.5 Bottom plate uniformly resting on the substructure shall have a minimum thickness of 6 mm for tank upto 10 m in diameter and 8 mm for higher




diameter. Bottom plate shall project at least 25 mm allround beyond the outer edge of weld attaching the bottom to the shell plate.

11.3.6 For large diameter tanks supported cone roof shall be provided. Arrangement of columns and rafters shall in general be as per fig 9 and 10 of IS:803. Roof plates shall have a minimum thickness of 6 mm and shall not be attached to the supporting member. A curb angle shall be provided at the top of the shell in line with clause 6.3.6.2 of IS:803. Roof plates shall be attached to the curb angle with a continuous fillet weld on the top side only. Minimum slope of roof shall be 1 in 16. 11.3.7 Rafter clips for the outer row of rafters shall be welded to the shell. Columns shall not be rigidly attached to the bottom plates guide. Clips shall be welded to the tank bottom to prevent lateral movement. 11.3.8 Roof supporting columns shall made from structural shapes or pipe or built up section. Suitable base frames or reinforcing pads shall be provided at the column base to distribute loads coming on the tank bottom. 11.3.9 Appurtenances and mountings covered under section 7 of IS:803 shall be provided in addition to any other appurtenance which the BIDDER considers essential for the safe and smooth operation of the fuel oil storage and oil handling system. 11.3.10 After erection and inspection of the tank, the tanks shall be tested as per clause 12 of IS:803. Leakage, if any noticed shall be repaired to the satisfaction of the OWNER and the tank retested to satisfy acceptance criteria.

11.3.11 Tanks shall be provided with two coats of epoxy coating for internal surfaces over two coats of compatible primer. External surfaces shall be provided with two coats of synthetic enamel paint over two coats of red oxide zinc chromate primer.

11.4 Cooling Water Conduits Design, installation and testing of the pipe shall in general follow the provision of “Steel pipe - A guide for design and installation“ - AWWA Manual M11 - published by American Water Works Association. Steel used shall conform to IS:2062. Minimum earth cover over the pipe shall be 1500 mm. Internal surface shall be provided with epoxy coating and the external surface shall be provided with coal tar enamel wrapping. Bedding shall be of sand. Thrust blocks shall be provided at all bends. Internal design pressure shall be the shut off head as furnished by the pump vendor, 1.5 times the pump working head or maximum surge pressure computed from surge analysis whichever is greater. However for surge pressure the allowable stresses can be increased by 25%. External pressure due to earth pressure, surcharge pressure of 2 t/sq.m




and at road crossings pressure due to vehicles shall be considered. In addition a vacuum pressure of 9 m water column shall be considered while checking against buckling. All site joints shall be inspected by radiography. Internal surface of the conduit shall be provided two coats of epoxy paint over two coats of compatible primer.



SECTION: D4.6e PART E - OUTDOOR CIVIL WORKS

1.0 DRAINAGE AND SEWERAGE

All drainage lines for storm water, sewage and waste drainage etc. shall preferably be laid in service aisles close to the road. Separate network shall be provided for lines of storm water, sewage, and waste drainage.

1.1 Surface Drainage

1.1.1 All the paved and unpaved areas shall be adequately drained. The surface drainage system shall be designed for surface washings and / or rain / fire water as the case may be. Unpaved open areas shall be drained through RCC drains and connected to main storm drains.

1.1.2 The paved area shall be sloped towards the drains with a minimum slope of 1 in 100. The maximum drainage travel extent shall be limited to 10 metres. 1.1.3 The surface drainage from uncontaminated area shall be connected to the nearest open storm water drains through rectangular drains. Contaminated area surface drainage shall be collected through separate network. 1.1.4 The interconnecting pipes and rectangular drains shall be sized for carrying

the design discharge when running full.

1.1.5 The rectangular drains shall be minimum 450mm wide of RCC construction. The pipes for water drainage system shall be of RCC class NP2 conforming to IS:458 with minimum size of 150 mm NB. However for road crossings etc. pipe of class NP3 shall be provided. For rail crossings, pipes conforming to railway loading standards shall be provided. If sufficient clearance cannot be provided between the top of the pipe and road top, the pipes shall be encased in RCC.

1.1.6 The maximum velocity for pipe drains and open drains shall be limited to 2.4 m/sec and 1.8 m/sec respectively. However minimum velocity for self cleaning of 0.6 m/sec shall be ensured. Slope of drain shall not be milder than 1 in 1000.

1.1.7 Minimum cover of 450 mm shall be provided over drainage pipes in paved areas.

1.1.8 Garland drains, minimum 300 mm wide shall be provided allround the building to lead away roof drainage to plant drainage system. Plinth protection in PCC grade M 15 shall be provided between building wall and drain with appropriate slope.

1.2 Storm Water Drainage System

1.2.1 The plant storm water drainage system shall take into account the topography of the plant area, area drainage patterns and intensity of rainfall etc. The




drainage system shall be designed for a precipitation intensity equal to hourly rainfall for a return period of 1 in 50 years. However, storm frequency of 100 years return period shall be applied for coal storage area.

1.2.2 All storm water drainage shall preferably be conveyed through storm water drains provided on both sides of the roads and shall be designed to drain the appropriate catchment area including road surface, open and covered area etc. The drains shall be minimum 450 mm wide at the base. Drain top cover shall be covered with RC precast slab. Grating shall be planned at every 4mts for easy maintenance of drains. 1.2.3 In the main plant area all open drains rectangular in cross section shall be in RCC of grade M 30. The thickness of side and bottom shall be minimum 125 mm or as per design considerations whichever is higher. 1.2.4 The pipes for water drainage system shall be of concrete of class NP2 conforming to IS:458. However for road crossings etc. higher strength pipe of class NP3 shall be provided. Diameter of pipes used for drainage / culverts shall be between 300 mm to 600 mm. Beyond 600 mm, box drains / culverts shall be provided. 1.2.6 Surface drains shall normally have a bed slope not milder than 1 in 1000 along longitudinal direction and RCC pipes shall have such slopes so as to have effective discharge. The maximum velocity for pipe drains and open drains shall be limited to 2.4 m/sec and 1.8 m/sec respectively. However, minimum velocity for self cleaning of 0.6 m/sec shall be ensured at peak flow condition (i.e. 3 times average flow) for pipes flowing at half full. 1.2.7 Suitable manholes shall be provided to pipe drainage lines at every 30 m intervals, at junctions and at change of gradient, alignment and diameter of pipe and shall be of RCC construction. Minimum size of manholes shall be

1.0m x 1.0m. All manholes shall be designed considering maintenance, inspection and cleaning of pipes. Easy accessibility and safety shall also be given due consideration.

1.2.8 The cushion over the pipes for storm culverts shall be minimum 600 mm. Where less cushion is available, pipe shall be encased in RCC M 20. Suitable RCC structures shall be provided at drops / falls to prevent scouring or damage to surface.

1.2.9 Invert of drainage pipe / drain shall be decided in such a way that the water can easily be discharged above the high water level in water course outside the plant boundary to which the storm water is to be led.

1.3 Plant Effluent Drainage (Oily Waste / Process Waster Drainage)

1.3.1 The oily / process waste shall be drained / collected through a separate sewer system consisting of underground (over ground if required) cast iron pipes of Class - LA conforming to IS : 1536. Catch pits shall be provided at




the source location and they shall be interconnected by buried pipes. No bends and branches shall be provided in the pipe line. Manholes shall be provided at all junctions of pipes. Catchpits shall have a minimum internal dimension of 600 mm x 600 mm. They shall be of RCC construction and provided with CI grills.

1.3.2 The main and branch connection pipes shall be sized for the expected

maximum discharge subject to a minimum of 250 mm NB and 100 mm NB respectively. The pipes shall be adequately sloped for drainage and shall carry flow to neutralisation pit / ETP / Oil water separator as required.

1.4 Sewage System

1.4.1 Cast Iron Pipes of Class - LA conforming to IS : 1536 shall be used below ground level for sewage disposal. Pipes connecting toilet facilities to manholes shall be minimum 100 mm diameter NB. Pipes connecting various manholes shall be minimum 150 mm diameter NB.

1.4.2 Sewers shall have such slopes so as to have effective discharge. Sewers shall be designed for a minimum self cleaning velocity of 0.75 m/sec for peak flow condition (assumed as 3 times the average flow) and pipes flowing half full. The maximum velocity shall not exceed 2.4 m/sec. 1.4.3 Suitable manholes shall be provided to pipe sewage lines at every 30 m intervals, at junctions and at change of gradient, alignment and diameter of pipe and shall be of RCC construction. Details of manholes shall be as per IS:4111 ( Part-I ). Minimum size of manholes shall be 1.0m x 1.0 m. All manholes shall be designed considering maintenance, inspection and cleaning of pipes. Easy accessibility and safety shall also be given due consideration. 1.4.4 Not used 1.4.5 Manual on Sewerage and Sewage treatment (published by Central Public

Health Environment Engineering Organisation, Government of India) shall be followed for design purpose.

2.0 INTER PLANT TRENCHES

2.1 All cable and pipe trenches shall be of RCC with minimum M20 grade. Trenches located outside the buildings shall project at least 150 mm above finished formation level to avoid entry of storm water into the trenches. The bottom of trench shall be provided with suitable slope for draining out collected water into a sump pit.

2.2 Trenches shall be covered using precast RCC cover of minimum M20 grade, each not weighing more than 65 kg and shall be provided with a lifting hooks. 3.0 Roads & Parking areas




Roads & Parking areas shall be of flexible pavement type and shall be designed in accordance with the provision of the relevant IRC Codes of Practices.

3.1 Roads shall be designed as per IRC-37:1984 “Guidelines for the design of

flexible pavements”. California Bearing Ratio (CBR) method shall be adopted for the design of roads.

3.2 Sub base shall be of granular material i.e. laterites, moorum, natural sand, gravel, crushed stone (grading-1) or combination thereof laid over well compacted subgrade. Granular base shall be of water bound macadam course (WBM) construction. The wearing coarse shall be bituminous macadam binder course with open graded premix carpet laid over it. Shoulder provided on either sides shall be in murrum construction of 150 mm compacted thickness. Kerbs of PCC or stone shall be provided to distinguish carriage way. 3.3 The geometric design of roads shall be done in accordance with IRC-73. Road widths and curves shall have adequate space for manoeuvring of vehicles. Transverse camber of 1 in 60 shall be provided for the black topping of roads and a slope of 1 in 40 shall be provided on shoulders. Finished top (crest) of roads shall be 250 mm above the surrounding grade level. 3.4 Minimum radius of curvature along the inner side of the carriageway shall be generally 15m. However for minor roads this shall be reduced suitably as per layout requirements and site conditions. Road width and turning radii shall also be checked for to take largest foreseeable vehicles and equipment, which can reasonably be expected. 3.5 All service and utility lines crossing under roads shall be taken through

concrete pipes / ducts and designed for imposed loading. Number of such crossings shall however be kept to a minimum.

4.0 PAVING 4.1 R C C Paving

4.1.1 R.C.C paving of grade M20, minimum 125 mm thick laid to a slope of 1 in 100 towards the nearest drain, with reinforcement placed 50 mm from the top surface, shall be provided in the following areas. (i) Entire backside of the main turbine building up to the farther edge of chimney. The paving shall extend to a minimum of 5 m on either side from the outer most face of equipment structures in the other direction. (ii) 5 m wide corridor all around Power House.




4.1.2 The underbed shall consist of well compacted ground supporting dry rubble soling of compacted thickness 225 mm with interstices properly filled with grits, followed by a layer of PCC of M 7.5, 50 mm thick. 4.1.3 Paving in crane corridor shall be designed for the maximum load due to movement of crane.

4.2 P C C Paving 4.2.1 PCC paving of nominal mix of grade M15, 150 mm thick laid over 150 mm thick

compacted rubble soling shall be provided around all building as plinth protection to a width of 750 mm or the distance between the brick wall to the garland drain.

a) Complete Transformer Yard, covering area between turbines building up to the fencing of the Transformer yard. b) Plinth protection around all building to a width of 1000 mm or the distance between the brick wall to the garland drain whichever is higher.

4.3 Stone Aggregate Paving 4.3.1 Entire switchyard area and main transformer yard area shall be provided with 75 mm thick paving of 40 mm size stone aggregate on top and 75 mm thick paving of 20 mm stone aggregate below. Before laying the paving, the ground surface shall be treated with antiweed chemicals as per manufacturer recommendations. 4.3.2 For auxiliary transformer yard, paving of stone aggregate of 75 mm thick using 20 mm size aggregate shall be provided after compacting the under bed and treating with anti-weed chemicals.



PART F - FINISHING WORKS

FINISHES

SECTION: D4.6f

The minimum quality of finishes used for various building areas are furnished in this section. The bidder is at liberty to use superior finishes provided all specific requirements for the finish specified herein below are satisfied.

1.0 FLOORING The nominal total thickness of floor finish shall be 50 mm including under bed and topping. The flooring shall be laid on already matured concrete base. Generally the under bed for floors shall consist of cement concrete 1:2:4 with stone chips 12.5 mm down graded as coarse aggregates. The under bed shall be provided appropriate slope towards catch pit for floor drainage.

1.1 False Flooring System

Removable type false flooring system shall be provided in computer rooms and control rooms as required. RCC floor slab will be sunk to a depth 600 mm which shall be height of the false floor system. The flooring shall consist of fire resistant phenol formaldehyde bonded particle board panels 600x600x35 mm size, mounted on steel pedestals of adjustable height and supporting steel grid system to provide under floor space. 2 mm thick flexible anti-static PVC topping on top and PVC strip edging on sides of each panel shall be provided.

1.2 PVC Floor Finish Two mm thick PVC tile as per IS:3462 and laid as per IS:5318 over concrete under bed of 48 mm shall be provided in all control rooms unless specified otherwise. PVC tiles shall ensure anti static surface.

1.3 Epoxy coating This shall be provided for Steam Turbine building operating floor as per the manufacturers requirement.

1.4 CARBORANDUM TILES

This shall be provided for steam and Gas/steam turbine building floor area. Polished heavy duty cement concrete tiles (carborandum) of 300x300x22 mm thick manufactured as per IS: 1237 using colouring pigment and hard chips like carborandum, quartz etc shall be laid as per IS: 1443 over concrete under bed to result in overall thickness of 50 mm.

1.5 Terrazo Flooring



PART F - FINISHING WORKS SECTION: D4.6f

This shall be provided in general circulation area like lift entrance area, office area, laboratory etc. Tiles shall generally be of 250 x 250 x 20mm size laid over concrete bedding to result in an over thickness of 50mm.

1.6 Polished Granite Flooring

This shall be provided in areas such as Administration building office area, corridor, staircase etc. Tiles shall be of 25mm thick hard polished granite laid over cement base mortar on concrete bedding.

1.7 IPS flooring

IPS (cement concrete flooring) with metallic floor hardener topping 12 mm thick with a total thickness of 50 mm shall be provided in maintenance and unloading area of turbine building, warehouse floors, operating floor of pump house, warehouse & stores and other plant building areas where heavy duty flooring is required.

IPS flooring with non-metallic floor hardener shall be provided in all MCC and switchgear rooms, which are not air-conditioned. IPS flooring shall also be provided in areas, which are not provided with any special finish. Areas, which are likely to be subjected to oil spillage, shall be provided with two coats of oil resistant painting over IPS floor finish.

1.6 Granolithic Flooring

1.6.1 Granolithic flooring (cement concrete flooring in 1:1:2) with non-metallic floor hardener topping 12 mm thick with a total thickness of 50 mm shall be provided in maintenance and unloading area of GTG/STG building, permanent stores, and other areas where heavy duty flooring is required.

1.5.2 The other areas of station building, MCC and Switch gear rooms, AC plant rooms, chlorination rooms, relay rooms, DG house, Pump house floors etc., shall be provided with Granolithic Flooring without floor hardener. 1.5.2.1 Granolithic flooring shall also be provided in areas, which are not provided with any special finish. Areas which are likely to be subjected to oil spillage, the same shall be provided with two coats of oil resistant paint over Granolithic flooring.

1.6 Heavy Duty Ceramic Tiles

Heavy duty ceramic tiles with matt finish shall be used in toilets, pantry, electronic cubicle rooms, UPS rooms etc. The tiles shall be 300 x 300 x 7 mm of approved shade brand and colour.




1.7 Acid / Alkali Resisting Tiles

SECTION: D4.6f

Battery rooms and other areas coming in contact with acid / alkali vapours or fumes shall be given acid / alkali resistant tiles 25 mm thick, jointed with acid / alkali resistant cement slurry. Bedding shall comprise of potassium silicate mortar conforming to IS:4832 (Part-I) and resin based mortar like epoxy for jointing. Total thickness of flooring shall be 50 mm. Ceramic unglazed vitreous tiles conforming to IS:4457 with minimum thickness of 20 mm may also be used as acid / alkali resistant tile. The above specification do not apply to D.M. Plant.

1.8 Integral Floor Finish

For cable vault rooms, mill and bunker bay floors, and floors of wagon tippler shed, reclaim hopper shed, crusher house, junction towers, pent house, elevator machine room shall be provided with floor finish integral to the concrete base as per IS : 2571.

1.9 Cast-in-situ Terrazo Risers and treads of staircases shall be provided with cast in situ terrazo finish. This shall be laid as per IS:2114, using white cement or cement with colouring pigment. Chequered finish shall be provided for treads. Total thickness of the finish shall be 25 mm.

1.10 Acid / Alkali resistant Tiling / Brick lining in D.M Plant 1.10.1 Bitumen primer followed by 12 mm thick bitumastic, 6 mm thick potassium

silicate mortar bedding and 38 mm thick alkali / acid resistant bricks as per IS:4860 shall be provided for CPU regeneration area, Chemical house floor, effluent drains, floors around equipment and chemical handling vessels, chemical storage area for the floor, curbs and sumps, all as per the acid / alkali proofing specialist Contractor’s requirement. The balance area of DM plant building shall be provided with integral floor finish.

1.10.2 For floor of neutralising pit, the finish shall be as follows. Bitumen primer followed by 18 mm thick bitumastic, 6 mm thick potassium silicate mortar bedding and 75 mm thick acid / alkali resistant brick as per IS:4860.

1.10.3 For walls of neutralising pit, the same specification as 1.10.2 shall apply except that thickness of the brickwork shall be 115 mm with suitable pilasters at 2000 mm c/c.

1.10.4 Special instruction to be followed for acid resistant lining in neutralising pit shall be as follows.

i) The structures shall be tested for water tightness.




ii) Surface on which lining is to be applied shall be prepared as per IS:2395.

iii) Joints between acid resistant bricks / tiles shall be filled with resin type mortar conforming to IS:4832 ( Part II ). Seal coat of ready made epoxy paint shall be provided at the joints to cover up any porosity.

iv) Acid resistant bricks shall be laid with 6 mm wide and 20 mm deep pointing. Pointing shall be with epoxy / furane / CNSL as per the requirement of the agency guaranteeing the performance of lining. v) Under side of neutralising pit roof slab, all precast slabs / steel covers over effluent drains shall be given two coats of epoxy coating, each coat of 150 microns thick.

vi) Acid / alkali resistant treatment shall extend at least 1 metre on all sides from the outermost periphery of pedestals / saddles for indoor installations and 2 metres allround for outdoor installations.

1.11 Polished Vitrified Tiles

Polished vitrified tiles shall be provided in main control building. The tiles shall be of 400 x 400 or 600 x 600, 7.5mm in size and shall be of approved shade, brand and colour.

1.12 MISCELLANEOUS 1.12.1 PVC nosing shall be provided for edge protection of R.C.C. stair treads. 1.12.2 Angles 50x50x6 mm (minimum) with lugs shall be provided for edge protection of cut outs / openings in floor slabs, edge of drains covering gratings, edge of R.C.C cable / pipe trenches of any other place where breakage of edges / corners is expected.

1.12.3 Floors of switchgear rooms shall have embedded steel channel suitable for easy movement of breaker panel.

1.12.4 Stairs of control & switchgear building shall have granite finishing with granite wall cladding for a height of 1000 mm from finished step level. The hand rail shall be of stainless steel.

2.0 SKIRTING / DADO 2.1 150 mm skirting matching with floor finish shall be provided in all areas

unless specified otherwise elsewhere. 2.2 Toilets and locker rooms shall be provided with dado of 2100 mm high with glazed tiles of minimum 5 mm thickness generally as per IS:777. 2.3 For auxillary Control room and control equipment room minimum 5 mm thick decorative coloured ceramic tiles shall be provided upto false ceiling




level. For main control room vitrified polished tiles shall be provided up to the false ceiling level.

2.4 For battery room and other areas coming in contact with acid / alkali spillage / fume, dado of acid / alkali resistant tiling as per IS:4457 shall be provided to a height of 2100 mm set in potassium silicate mortar and joints pointed with resin bonded mortar.

2.5 Staircase wall shall be given dado of cast in situ terrazo to a height of 2100 mm.

2.6 Entrance lobby and lift area shall be provided with granite tile dado.

3.0 METAL CLADDING 3.1 Permanent Colour Coated Sandwiched Insulated Metal Cladding and

Roofing System.

3.1.1 Trough zinc-aluminium alloy coated (both sides) M.S. sheet having 0.6 mm minimum thickness shall be used on external face (outer face) of cladding system. Weight of coating shall not be less than 150 gm / sq.m. The outer side (exposed face) shall be permanently colour coated with Polyfluro Vinyl Coating (PVF2) of Dry Film Thickness (DFT) 20 microns (minimum) over primer. Inner side of external sheet shall be provided with suitable pre-coating of minimum 7 microns. 3.1.2 Galvanised M.S. sheets of minimum 0.6 mm thickness shall be used as inner liner (internal face) of cladding system. The exposed face shall be permanently colour coated with silicon modified polyester paint of DFT 20 microns (minimum) over primer. Inner face of internal sheet shall be provided with suitable pre-coating of minimum 7 microns. The rate of galvanising shall not be less than 150 gm / sq.m. 3.1.3 The permanent colour coated sheet shall meet the general requirements of IS:14246 and shall conform to class 3 for the durability. 3.1.4 Inner sheet shall fixed directly to side runners and Z spacers made of at least 2 mm thick galvanised steel sheet of grade 375 as per IS:277. Inner sheet shall be fixed at the rate not more than 0.75 m centre to centre to hold the insulation and external sheeting. 3.1.5 The insulation shall be of bonded mineral wool of minimum thickness 50 mm conforming to IS:8183, having a density of 32 kg / cu.m for glass wool & 48 kg / cu.m for rock wool.

3.1.6 For roof sheeting the specification remains same as that of side cladding except the thickness and galvanisation. The minimum thickness of roof sheeting shall be 0.8mm with galvanisation rate of 275 gm/sqm




3.1.6 Prefabricated sandwiched polyurethane PUF panel system may also be used for side cladding and roof sheeting

3.2 Permanent Colour Coated (non-insulated) Metal Cladding System

3.2.1 Trough zinc-aluminium alloy coated not less than 150 gm/sq.m M.S. sheets having 0.6 mm minimum thickness shall be used for the cladding system. The outerside (exposed face) shall be permanently colour coated with PVF2 paint of minimum DFT 20 microns over primer and the inner side (internal face) shall be coated with same paint of minimum DFT 12 microns over primer. These shall be fixed directly to runners. The sheets shall meet the general requirement of IS:14246 and shall conform to class 3 for the durability. For roof sheeting the specification remains same as that of side cladding except the thickness and galvanisation. The minimum thickness of roof sheeting shall be of 0.8mm with galvanisation rate of 275 gms/sqm

3.3 Flashings, Cap, Trim Clousure etc. All flashings, trim closures, caps etc. required for the metal cladding system shall be made out of plain sheets having same material and coating specification as mentioned above for the outer face of the sandwiched metal cladding.

4.0 PLASTERING

4.1 For sand cement plaster, sand and cement in the specified proportion shall be mixed dry on a watertight platform and minimum water added to achieve working consistency.

4.1 Details furnished below do not include special types of plaster / plaster finishes which may be provided to enhance the architectural appeal. BIDDER may propose such superior plaster finish in his Bid.

4.1 External face of all walls shall be provided with 18 mm thick cement mortar plastering with an under layer of 12 mm thick in CM 1:6 and top 6 mm thick layer in CM 1:4 with approved water proofing compound.

4.2 For internal walls 18 thick plaster in CM 1:6 shall be provided on the uneven side of the wall and 12 mm thick plaster in CM 1:6 on the even side of the wall.

4.3 Inside surfaces of walls shall be provided with 2 mm thick plaster of paris punning over the plastered surfaces in office areas, entrance lobby, corridor, control equipment room and all other air conditioned rooms.




4.4 Ceiling plastering of 6 mm thick with CM 1:4 shall be provided for all the buildings except cable valults.

4.5 All plastering work shall conform to IS:1661. 4.6 Internal plastering on walls shall be done to cover surfaces from skirting level

to bottom of roof slab in all areas including areas where false ceiling is provided. ALL drips, grooves, mouldings, and cornices as shown on drawing or instructed by the owner shall be done with special care to maintain true lines, levels and profiles. After the plastering work is completed, all debris shall be removed and the area left clean.

Neat cement finish: After achieving a true plastered surface with the help of a wooden straight edge, the entire area shall be uniformly treated with a paste of neat cement at the rate of 1 kg. Per Sq.M. and rubbed smooth with a trowel.

Curing: All plastered surface after laying, shall be watered, for a minimum period of seven days, by an approved method, and shall be protected from excessive heat and sunlight by suitable approved means. Moistening shall commence, as soon as the plaster has hardened sufficiently and not susceptible to damage. Each individual coat of plaster shall be kept damp continuously, for at least two days, and then dried thoroughly, before applying the next coat.

5.0 PAINTING 5.1 Details furnished here in below are the minimum acceptable standard for

painting. Superior finish if any required by BIDDER to enhance overall appearance will be permitted if such finish meet with the technical requirements.

5.2 Water proof cement based paint as per IS:5410 shall be provided on

external faces of walls, sunshades, etc. 5.3 Inside surfaces shall be provided with Oil Bound Distemper for all areas as per IS: 428 except for Control room, Control equipment rooms, and all air conditioned areas for which acrylic emulsion paint shall be provided as per IS: 5411. 5.4 Walls in D.M.Plant shall be provided with chlorinated rubber based paint.

Walls above Dado in battery rooms shall also be provided with similar painting.

5.5 All ceilings shall be provided with water bound distemper as per IS:427. 5.6 Oil resistant paint as per IS:161 shall be provided for oil canal and oil

equipment room.




SECTION: D4.6f

5.7 All wood work shall be provided with fire resistant transparent paint as per IS162 over french polish as per IS:348 or flat oil paint as per IS:137.

5.8 Painting for structural steel have been specified else where in this

document.

5.9 Following general instruction for painting shall be followed.

i) For painting on concrete, masonry and plastered surfaces IS:2395 parts I and II shall be followed.

ii) For painting on wood work IS:2338 part I and II shall be followed. iii) All paints shall be of brand and make as per the approval of

OWNER. iv) A minimum of two finishing coats of paint over a primer shall be

provided to give a smooth uniform finish for the painted surface. v) All painting on masonry or concrete surfaces shall preferably be

applied by rollers. vi) Thinner shall not be used with textured paint (sandtex matt etc.)

finish. viii) All fire exits shall be painted in Post office red colour shade which shall not be used any where except to indicate emergency or safety measure. In detailing of all buildings, fire safety requirements conforming to IS: 1641 and IS:1642 shall be followed.

6.0 Roof covering

All buildings having R.C.C slabs over structural steel framing are provided with troughed metal sheet decking which acts as permanent shuttering. These sheets shall meet the general requirements of IS:14246 and shall conform to class 3 for durability. The sheeting shall be permanently colour coated galvanised MS troughed metal sheet decking of approved profile with minimum base metal thickness of 0.8 mm and minimum trough depth of 38mm. Silicon modified polyester painting shall be used for permanent coating over galvanised surface with minimum rate of galvanising of 180 gm of zinc per sq.m. Dry film thickness of colour coating shall be at least 20 micron.

6.1 Roof of other buildings having RCC frame work / structural steel framing shall

have cast in situ RCC slab with conventional shuttering.

7.0 ROOF DRAINAGE AND WATER PROOFING 7.1 For efficient drainage of rainwater, roof concrete shall be given a gradient

of a minimum of 1 in 100. The gradient shall preferably provided by sloping the structural framing system itself. Gradient may also be provided




using screed concrete of grade M20 using 12.5 mm downgraded aggregate. But the average thickness of such screed concrete shall be restricted to about 50 mm.

7.2 All roofs shall be provided with extra heavy duty water proofing treatment

comprising of

i) seven courses as per IS:1346 using 3 layer of glass fibre based felt as per IS:7193

ii) 50 mm thick foam concrete as per IS:6598 for thermal insulation iii) 15 mm thick cement sand plaster 1:4 iv) chequered cement tiles as per IS:13801 shall be provided over water proofing treatment in areas where movement of personnel is expected. Minimum width of pathway if provided only locally shall be 1000 mm.

iv) In areas such as roof of control room building etc. where handling of equipment is anticipated, the foam concrete may be replaced by 40 mm screed concrete of grade M 20.

7.3 All roof waterproofing shall be provided using high solid content liquid applied elastomeric water proofing membrane with separate wearing course as per ASTM C-898. Thickness of the membrane shall be a minimum of

1.5mm. The treatment includes application of polymerised mortar over sloped roof to achieve a smooth surface and a primer coat. Wearing course shall be 40mm screed of 1:2:4 concrete cast in panels of 1.2mx1.2m and reinforced with 0.56mm dia galvanised chicken wire mesh and joints sealed using sealing compound. Accessible roof shall be provided with chequered cement tiles as per IS: 13801 over water proofing treatment in areas where movement of personnel is expected. Minimum width of pathway if provided locally shall be 1000 mm. China mosaic tile flooring shall be laid over the water proofing layer to protect against heat over all building roofs.

7.4 Number and size of rain water down take pipe shall be decided based on the provisions of IS:1742 and IS:2527. The pipes shall be UPVC pipe conforming to class-3 of IS: 4985. It is recommended that the minimum diameter of the pipe shall be kept as 160 mm and there shall be a minimum of two pipes provided on each gutter. The down comer pipes shall be suitably concealed with masonry work, cement concrete or sheeting to match with the exterior finish.

8.0 FALSE CEILING AND UNDER DECK INSULATION 8.1 All air conditioned areas, entrance lobbies, corridors of administrative

building and control room building shall be provided with the suspended false ceiling system. Under deck insulation system shall be provided on the under side of the roof / floor slab of the air conditioned areas based on the functional requirement. Ceiling of air washer/chiller room shall also be provided with under deck insulation.




8.2 Main Control room shall be provided with Aluminium false ceiling system (LUXALON). This shall comprise of 84 mm wide 12.5 mm deep closed type plain panels of approved colour, roll formed out of 0.5 mm thick corrosion resistant aluminium alloy AA 5050 fixed on roll formed carriers. Additional hangers and height adjustment clips shall be provided for return air grills, supply air diffusers, light fixtures, AC ducts etc.

8.3 All air conditioned areas and other control rooms shall be provided with Gypboard false ceiling modular system. This shall consist of 600x600x12.5 mm gypboard with one coat of primer and two or more coats of acrylic emulsion paint. The suspension system shall consist of 6 mm diameter galvanised steel rods suspended from ceiling supporting aluminium grid of 38x25x1.5 mm and cross tie of 25x25x1.5 mm and aluminium angle of 25x25x1.5 mm.

8.4 Suitable M.S channel (minimum ISMC100) grid shall be provided above false ceiling for movement of personnel to facilitate maintenance of lighting fixtures, AC ducts etc. 8.5 CONTRACTOR shall prepare a layout of the false ceiling system incorporating light fixtures, supply air diffuser, return air grills, firedetectors, fire protection sprinklers etc. such that the ceiling looks aesthetically pleasing. Work shall commence only after the OWNER approves the layout. 8.6 Under deck insulation shall comprise of 50 mm thick resin bonded mineral wool insulation mat conforming to IS:8183. This mat shall be backed with

0.05 mm thick aluminium foil and 24 Gx25 mm wire mesh netting. These shall be fixed to ceiling or wall as the case may be with 100x50x6 mm slotted mild steel plate welded to M.S. plate inserts embedded at the soffit of the slab at 600 mm c/c and 14 G steel wire drawn through slots and fixed to wire netting.

9.0 DOORS & WINDOWS

9.1 Unless specified all doors, windows and ventilators of air conditioned areas, entrance lobby of all buildings and windows/ventilators provided on the outer face of all buildings shall have, powder coated coated aluminium framework with glazing. All other doors (unless otherwise specified) shall be of flushed steel type and windows and ventilators shall be of glazed steel type.

9.2 Main entrance of the control room building and control equipment room shall be provided with air-locked lobby with provision of double doors of aluminium frame work with glazing. Doors shall be of double swing type or sliding type. 9.3 For common control building, double glazed wall panels with aluminium frame shall be provided between air-conditioned and non air-conditioned




areas and on the side of control room and control equipment room(s) facing the operating floor to have a clear view.

9.4 Single glazed panels with aluminium frame work shall be provided as

partition between two air-conditioned areas wherever clear view is necessary.

9.5 All steel doors shall consist of double plate flush door shutters. The door shutter shall be 45 mm thick with two outer sheets of 18 G rigidly connected with continuous vertical 20 G stiffeners at the rate of 150 mm centre to centre. Side, top and bottom edges of shutters shall be reinforced by continuous pressed steel channel with minimum 18 G. The door shall be made sound proof by filling the inside void with mineral wool. Doors shall be provided with all hardware and fixtures like door closer, tower bolts, handles, stoppers, aldrops, etc. Steel windows and ventilators shall be as per IS: 1038. 9.6 Wherever functionally required rolling shutters with suitable operating arrangement manual / Electric shall be provided to facilitate smooth operations. Rolling shutters shall conform to IS:6248. 9.8 All windows and ventilators on ground floor of all buildings located in

isolated areas shall be provided with suitable anodised aluminium grill.

9.9 Fireproof doors with panic devices shall be provided at all fire exit points as per the recommendations of Tariff Advisory Committee (TAC). These doors shall generally be as per IS:3614 (Part I and Part II). Fire rating of the doors shall be as per TAC requirements. However minimum rating shall be 2 hours. These doors shall be double cover plated type with mineral wool insulation.

9.10 Hollow extruded section of minimum 3 mm wall thickness as

manufactured by INDAL or equivalent shall be used for all aluminium doors, windows and ventilators.

9.11 For common control building, double glazed wall panel with aluminium frame shall be provided between air-conditioned and non air-conditioned areas.

Number, type, make and shade of all Hardware’s and fixture used shall be of shall be provided as per owner’s selection.

10.0 Glazing

10.1 All ventilators and windows on external face of building shall be provided with light tinted sheet glass of minimum 6 mm thickness.




10.2 Where specified, double glazing shall consist of two 6 mm thick clear toughened light tinted safety glass conforming to IS:2553, hermetically sealed and separated by 12 mm thick gap for thermal insulation. 10.3 For single glazed aluminium partitions and doors, Float glass or flat

transparent light tinted sheet glass of minimum 6 mm thickness shall be used.

10.4 Ground glass / frosted glass of minimum 4 mm thickness with light tint shall be used for all windows / ventilators in toilets.

10.5 Unless specified otherwise in this specification minimum thickness of

plain sheet glass used for windows/ventilators shall be 4 mm.

10.6 Float glass or flat transparent sheet glass shall conform to IS:2835. 10.7 All glazing work shall conform to IS:1083 and IS:3548.

11.0 WATER SUPPLY AND SANITATION 11.1 Roof water tank of adequate capacity depending on the number of users

and 8 hours requirement shall be provided for each building and pump house. Polyethylene water storage tank conforming to IS:12701 shall be used. The tank shall be complete with all fittings including float valve, stop cock etc.

11.2 Galvanised M.S. pipe of medium class conforming to IS:1239 shall be used for internal piping works for potable water supply.

11.3 Sand C.I pipes with lead joints confirming to IS1239 / UPVC pipes conforming to Class-3 of IS: 4985 shall be used for sanitary works above ground level and for below ground level Cast Iron shall be used.

11.4 Minimum one toilet block with all the facilities shall be provided on each floor of main plant building. One toilet shall be provided in the boiler area. All other buildings where toilet is specified shall have one toilet block . The facilities provided in the toilet block shall depend on the number of users. However, minimum facilities to be provided shall be as stipulated below. IS:1172 shall be followed for working out the basic requirements for water supply, drainage and sanitation. In addition, IS:2064 and IS:2065 shall also be followed.

11.5 Each toilet block shall have the following minimum facilities. Unless specified all the fittings shall be of chromium plated brass (fancy type).

i) WC (Indian type) Orissa pattern (580x440mm) as per IS:2556 (Part-3) with all fittings including flushing arrangement of appropriate capacity and type - 1no.




ii) WC western type 390 mm high as per IS:2556 (part 2) with toilet paper roll holder and all fittings including flushing system of appropriate capacity and type - 1 no. iii) Urinal with all fittings with photo voltic control flushing system as

per IS:2556 (Part-6, Sec.1) - 2 nos. iv) Wash basin (oval shape) with all fittings as per IS:2556 to be fixed

on concrete platform finished with 12 mm thick polished granite stone - 2 nos.

v) Wall to wall Bathroom mirror (5.5 mm thick float glass) with bevelled edges including all fittings - 2 nos.

vi) Stainless steel towel rail (600 x 20mm) - 2 nos. vii) Stainless steel liquid soap holder cum dispenser - 2 nos. viii) Janitor room. ix) Provision for installation of water cooler outside the toilet. x) Provision of ventilation shaft.

Unless specified all fittings in the toilets shall have same specification as stipulated above Attached toilets shall be provided for senior executive rooms and conference rooms shall have 1 WC, 1 urinal, 1 washbasin, 1 mirror, 1 no. Towel rail, 1 liquid soap holder cum dispenser. WC shall be of western type 390 mm high as per IS:2556(Part-2) with toilet paper roll holder and all fittings including flushing valve of appropriate capacity and type.

11.6 HRSG area toilet shall have minimum 2 no. WC (Indian type), 4 no. urinals, 4 no. wash basins, 4 no. mirrors, 4 no. towel rails, 4 no. soap holder cum dispenser, 2 no. showers, janitor room and a provision for installation of water cooler.

11.7 An eye and face fountain (combined unit with receptable) conforming to IS:10592 shall be provided in battery room, D.M plant and Chlorination plant.

11.8 Unless specified all fittings and fixtures in the toilets shall have same specifications as stipulated in Cl.No.11.5. 11.9 Stainless steel kitchen sink (750 mm size) for pantry shall be provided.

Platform in pantry shall be finished with 12 mm thick polished granite stone.

11.10 Laboratory sink shall be of white vitreous china of size 600x400x200 mm

conforming to IS:2556(Part-5) in laboratories and in battery room.

11.11 In GTG/STG building,, Control room building at least one toilet block shall be provided for ladies.

12.0 MISCELLANEOUS REQUIREMENTS




12.1 Doors and windows on external walls of buildings shall be provided with RCC sunshade over the openings with 300 mm projection on either side of the opening. Projection of sunshade from the wall shall be minimum 450 mm over window openings and 750 mm over door openings. 12.2 Doors and windows on the external walls of buildings with metal cladding shall be fixed by creating recesses in the cladding system.

12.3 Duct banks consisting of PVC conduits for cables shall be provided with proper sealing arrangement consisting of fire retardant sealing compound. 12.4 All floor openings for cables below electrical panel shall be sealed with fire sealing compound after cables are laid. 12.5 All openings in external walls provided for pipes, cables, ducts etc. shall be effectively sealed to prevent water seepage, after the routing of the services are over.

12.6 Natural Lighting & Ventilation

12.6.1 The area of windows shall be a minimum 15% of the floor area to ensure adequate natural lighting.

12.7.1 Fans shall be provided in general office area as per standard norms. 12.7 Sewerage system shall be provided with adequate ventilation for the pipe

work as well as manhole.

Finishes: (Brief details of finishes)




Brief description

SECTION: D4.6f

Building/ area

Ground floor:

Wall (Internal)

Oil bound distemper

Floor Ceiling

STG & GTG building Water

Carborandum bound

tiles

Roof Wall treatment (External)

Granular finish

Toilet

Dadoing for 2100mm high Heavy duty + Oil bound ceramic tiles distemper

distemper (Vineratex) Water Granular bound finish

distemper (Vineratex

Control and Switch gear building Central control room

Switch gear room Battery room

Office, Common areas & Corridor Cable room

Toilet

Acrylic emulsion paint


Acid & Alkali tile dadoing for 2100mm high + Chlorinated rubber based

paint


Oil bound distemper

Dadoing for 2100mm high + Oil bound

distemper

Heavy duty ceramic tiles

IPS with non metalic floor hardner

Acid / Alkali resistant tiles

Vitrified tile flooring

IPS with non metallic floor hardener


Water bound

distemper

Water bound

distemper

Chlorinated rubber based paint

Water bound

distemper

Water bound

distemper

Water bound

distemper

Elastomeric water

proofing treatment

Granular finish

(Vineratex)

Granular finish

(Vineratex

Granular finish

(Vineratex

Granular finish

(Vineratex

Granular finish

(Vineratex

Granular finish

(Vineratex



Electronic


SECTION: D4.6f

cubicle room & Acrylic Heavy duty Computer emulsion paint ceramic tiles room

Laboratory Acrylic Heavy duty room emulsion paint ceramic tiles

Water bound

distemper

Water Granular bound finish

distemper (Vineratex)

D M plant building

Chemical storage room Office Toilet

Water treatment area Laboratory room

Control room

Clarified Water pump house

Cooling Water pump house

Permeate water pump house

Chlorinated

rubber based paint

Acrylic

emulsion paint

Dadoing for 2100mm high + Oil bound

distemper

Chlorinated rubber based

paint


Acrylic

emulsion paint

Oil bound distemper

Oil bound distemper

Oil bound distemper





Heavy duty

ceramic tiles


IPS flooring with non

metallic floor hardener IPS flooring

with non metallic floor hardener IPS flooring

with non metallic floor hardener

Water bound

distemper

Water bound

distemper

Water bound

distemper

Water bound

distemper Water

bound distemper Water

bound distemper

Water bound

distemper

Water bound

distemper

Water bound

distemper

Elastomeric water

proofing treatment

Elastomeric water

proofing treatment

Elastomeric water

proofing treatment

Elastomeric water

proofing treatment

Granular finish

(Vineratex)

Granular finish

(Vineratex)

Granular finish

(Vineratex)

Granular finish

(Vineratex)

Granular finish

(Vineratex)

Granular finish

(Vineratex)




Granular

Raw water pump house

DG & Compressor house

BFP Building

Chlorination Building

Fuel Gas Control Room

Stores

Chemical Storage Room

Office

Toilet

Workshop

Workshop Building

Oil bound distemper

Oil bound distemper

Oil bound distemper

Chlorinated rubber based

paint


Chlorinated rubber based paints


Acrylic

emulsion paint

Oil bound distemper


metallic floor hardener


metallic floor hardener IPS flooring

with non metallic floor hardener

Acid / Alkali

resistant tiles


Acid/Alkali resistant tiles

Heavy duty

ceramic tiles



metallic floor hardener

Water bound

distemper

Water bound

distemper

Water bound

distemper

Water bound

distemper

Water bound

distemper

Water bound

distemper Water

bound distemper Water

bound distemper

Water bound

distemper

Elastomeric water

proofing treatment

Elastomeric water

proofing treatment

Elastomeric water

proofing treatment

Elastomeric water

proofing treatment

Elastomeric water

proofing treatment

finish (Vineratex) / Water proof cement paint

Granular finish

(Vineratex)

Granular finish

(Vineratex)

Granular finish

(Vineratex)

Granular finish

(Vineratex)

Filter water Pump House

IPS flooring Filter water Oil bound with non pump house distemper metallic floor

hardener

Water bound

distemper

Elastomeric Granular

water finish

proofing (Vineratex)

treatment




Door, Window and Ventilator Schedule

SECTION: D4.6f

Building/Structures

Temporary site office

GTG / STG building Control room building

Doors

Pressed steel door frame with double plate flush shutters

On external walls: Pressed steel doorframe with double plate flush shutters.

For equipment entry: steel sliding type / Rolling shutters

Office area: Pressed steel door frame with Pre laminated particle board (MDF exterior grade) shutters

Entrance lobby: Electro colour coated (anodised) aluminium framework with glazing.

FPD as per TAC requirement

Main entrance: Aluminium glazed double leaf with fixed sheet glass in anodised aluminium frame on either side.

Entrance to Control room: Electro colour coated (anodised) aluminium framework with glazing.

For equipment entry: steel sliding type / Rolling shutters Office area: Pressed steel frame with Pre laminated particle board (MDF exterior grade) shutters

A/C area: Electro colour coated (anodised) aluminium framework with glazing.

Switchgear room: Steel sliding type door.

Windows/Ventilators

Pressed steel frame with steel glazed window

Windows: Sliding type anodised aluminium framework with 6mm thick glass.

Ventilators (External faces): Aluminium framed louvers

Ventilators (Internal faces): Pressed steel frame with steel ventilators

Control room: Glazed aluminium sliding type windows

Switchgear room: Glazed aluminium windows with wire glass

Other area: Electro colour coated (anodised) aluminium framework with glazing.




Battery room: PVC Frame with PVC door, Cabin doors: Single leaf glazed aluminium doors

FPD as per TAC requirement.

SECTION: D4.6f

DM plant control Aluminium glazed doors. Aluminium glazed sliding windows. room & laboratory


Clarified water Pressed steel door frame with Pressed steel frame with steel Pump House double plate flush shutters glazed window

Clarified Water Pressed steel door frame with Aluminium glazed sliding windows. Pump House double plate flush shutters

Permeate Water Pressed steel door frame with Pressed steel frame with steel Pump House double plate flush shutters glazed window


Raw water Pump Pressed steel door frame with Pressed steel frame with steel House double plate flush shutters glazed window


DG & Compressor Pressed steel door frame with Steel windows with 6mm thick wire Building double plate flush shutters glass and MS grill work

For equipment entry: Rolling shutters

Workshop & Stores Pressed steel door frames with Steel windows with 6mm thick wire double plate flush shutters glass and MS grill work

For equipment entry: Steel sliding type/Rolling Shutters

Office Area: Prestressed steel frame with pre-laminated particle board (MDF exterior grade) shutters.




Note: Windows facing transformer yard shall be provided with 6mm thick wire glass in addition to specific requirement given above



PART G - INDUCED DRAFT COOLING TOWERS 1.0 SCOPE

SECTION: D4.6 g

The specification covers general requirements of materials, design, Construction and Testing of R.C.C works involved in the construction of Reinforced Concrete Induced Draught Cooling Tower.

2.0 CODES AND STANDARDS

A. Materials

i. IS:432 (parts 1 & 2)

reinforcement.

Mild steel and medium tensile steel bars and hard drawn steel wire for concrete

ii. IS:1785 Plain hard drawn steel wire for prestress- (parts 1 & 2) ed concrete.

iii. IS:1786 High strength deformed steel bars and wires for concrete reinforcement.

iv. IS:2062 Steel for general structural purposes.

v. IS:3589 Seamless or electrically welded steel pipes for water, gas and sewage (168.3mm

- 2032 mm)

vi. IS:8112 43 Grade Ordinary Portland Cement vii. IS:12330 Sulphate resisting portland cement.

B. Codes of Practice

i. IS:456 Code of practice for plain and reinforced concrete.

ii. IS:800 Code of practice for general construction

in steel.

iii. IS:875 Code of practice for design loads (other (part 1 to part 5) than earthquakes for building and

structures).

iv. IS:1080 Code of practice for design and construction of simple spread foundations.

v. IS:1343 Code of practice for pre-stressed concrete



PART G - INDUCED DRAFT COOLING TOWERS SECTION: D4.6 g

vi. IS:1893 Criteria for earthquake resistant design of structures.

vii. IS:2309 Code of practice for the protection of

buildings and allied structures against lightning.

viii. IS:2629 Recommended practice for hot dip galvanising on iron and steel.

ix. IS:2950 Code for practice for design and

(part 1) construction of raft foundation.

x. IS:3043 Code of practice for earthing. xi. IS:3370 Code of practice for concrete structures

(part 1 to 4) for storage of liquids.

xii. IS:12200 Code of practice for provision of water stops at transverse contraction joints inmasonry and concrete dams.

xiii. BS:4485 Specification for water cooling towers.

(All parts)

xvi. BS:8007 B.S.Code of Practice for design of concrete structures for retaining aqueous liquid.

2.1 The applicability of the provisions for conformity to the various codes and standards stipulated shall be in the following order.

a) Bureau of Indian Standards. b) British Standards Institution.

Wherever the above Standards are in conflict with the stipulations of this specification, the latter shall govern.

3.0 GENERAL REQUIREMENTS

3.1 The cooling tower shall be capable of cooling the rated quantity of water through the specified thermal range at the design wet bulb temperature and it shall conform to the other design parameters as stipulated in the Mechanical section of this document.

3.2 The scope of the BIDDER’S work for a cooling tower shall include

preparation of detailed designs and construction drawings and execution of




work including but not limited to supply of all material for foundations, shell, basin, fill with its supporting structure, staircases/walkways/platforms with handrailing, cold water outlet channels including gates, screens with handling arrangement, painting, access doors, water distribution system, aviation warning system, lighting, lightning protection system, with their associated hardware, etc., complete all as required to give satisfactory performance and as stipulated in various clauses in this document.

3.3 CONTRACTOR shall submit detailed design calculations and construction drawings to OWNER for obtaining his approval prior to commencement of work at site.

3.4 In the event, BIDDER has quoted in collaboration with another firm (either Indian or foreign), each and every drawing and design calculations submitted shall bear collaborator’s seal and signature indicating their approval. BIDDER shall also furnish, along with the offer, back-up guarantee for the performance of the cooling tower from the collaborator.

4.0 LOADINGS

4.1 Wind loads shall be considered as per IS:875 with appropriate values for K1, K2 and K3.

4.2 Earthquake loads shall be considered as per IS:1893 duly considering the type of soil and foundation system. Importance factor shall be taken as per IS 1893.

4.3 Dead load shall be considered as per IS:875. In addition to all loads, fungus

load of 100 kg/m2 shall be considered. 4.4 4.5 Live load on staircase, walkways and fan deck shall be taken as 5 KN/sq.m

4.6 Loading brought upon the cooling tower by permanent fixture shall be taken into account.

4.7 Design shall take into account all temporary loading during erection and construction stages.

4.8 Dead loads

Dead loads shall include the weight of structure complete with finishes, fixtures and partitions, false-ceiling and shall be taken as per IS: 875. Dead loads for natural draft cooling towers shall include self weight of structure, weight of fill material, weight due to algae growth, weight of falling water, weight of hot water pipe, weight of water in hot water channel and




distribution system including the self weight of channel and distribution system, weight of drift eliminators, etc.

4.8 Equipment, piping and associated loads

Loads of all equipments like Deaerator, Heater, Feed water Tank, Cooling Equipment, Motors, fan drive pulleys, Pumps, Monorails, Ventilation duct, air inlet & exhaust duct, Electrical control and relay panels, Cable load, Pipe load (static and dynamic), Tanks, AHU, Batteries, Air Washer, etc. shall be considered over and above the imposed loads. Equipment loads shall be considered as given by equipment supplier. Equipment loads which are of permanent nature shall be treated as dead loads.

4.9 Load Combination for Induced Draught Cooling Tower

Static Analysis and Design The following load conditions shall be considered for the design of the Fan supporting structure along with other load combinations as per IS:875.

i) Machine Load.

a. Load case 1 + equalvant static load due to unbalance force of fan corresponds to balance quality grade G 16mm/sec as per IS:1940.

b. Load case 1 + unbalance load corresponding to one blade failure load condition.

c. The strength design of the Fan supporting structure shall be done for worst loading combinations as stated above.

ii) Dynamic analysis

a) Free vibration analysis

A free vibration analysis of the fan supporting structure including the intermediate supporting structure for motor, gear box and pillow block (if applicable) shall be carried out to calculate the natural frequency of the fan supporting structure and its fundamental natural frequency shall be at least +20% away from the operating speed of the fan and motor.

b) Forced Vibration Analysis

Forced response analysis shall be carried out for the fan supporting structure including the intermediate structure supporting the motor, gear box and pillow block to calculate the vibration amplitudes for the following unbalance condition.

a) For unbalance load corresponding to balance quality grade Q 16 mm/sec of the fan as per IS 1940.




The amplitude so calculated shall be within the permissible values as specified by the fan manufacturer or IS-2974 whichever is more stringent.

iii) Mid Bearing supporting structure

The intermediate supporting structure for motor, gearbox and pillow block shall be so arranged that it does not cause any torsional moments on the beams/pedestals on which the intermediate support rests. The intermediate supporting structure shall be orthogonal to the grid of beams on which it rests. The motor shall be supported on a base frame.

5.0 CONCRETE WORKS

5.1 Cement used shall be OPC complying with IS:8112. Same brand of cement shall be used as far as possible through out the construction of the entire structure to enable to achieve uniform color and surface finish for the superstructure. In locations where chemical analysis of subsoil reveals high sulphate content, sulphate resistant cement shall be used below ground level.

5.2 Minimum grade of concrete for various R C C structural components shall be M30.

5.3 Minimum cement content per cubic meter of concrete shall be as per Table 5 of IS: 456.

5.4 In locations where high sulphate resistant cement has to be used below ground level, minimum cement content shall be as per Table 4 of IS:456.

5.5 Material, design, construction and workmanship in general shall conform to IS:456 in limit state design with a limiting crack width of 0.1mm. For prestressed concrete works, design, construction and workmanship shall be in accordance with IS:1343.

6.0 REINFORCING STEEL 6.1 Reinforcement bars shall conforming to IS: 432 grade I quality for mild

steel and IS: 1786 for yield strength deformed bars.

6.2 All the reinforcement bars used shall be of fusion bond epoxy coating as per IS 13620.

6.3 Steel wires for prestressing shall conform to IS:1785 ( part 1 & 2 ).

7.0 STRUCTURAL STEEL



PART G - INDUCED DRAFT COOLING TOWERS

7.1 Steel used shall conform to IS:2062.

SECTION: D4.6 g

7.2 All exposed steel work shall be protected by hot dip galvanising. The minimum coating of zinc shall be 900 gm / sq.m and shall comply with requirements of IS:2629 and IS:2633. Galvanised surfaces shall be further protected providing 2 coats of bituminous painting conforming to IS:9862 after applying etching primer coat as per IS:5666.

8.0 BASIN & COLDWATER OUTLET CHANNEL 8.1 The basin shall be divided into two compartments to facilitate complete

isolation of one half of the basin for the purpose of cleaning and maintenance, while the other half is in service.

8.2 The basin floor of each compartment shall be sloped towards a collecting sump for effectively draining the water to permit desilting/ desludging. To minimise obstructions to the flow of water, only the columns supporting the fill structure shall be projected above the basin floor. Water shall be drained from the sump into a drain chamber outside the basin by CI drain pipe embedded below the basin floor. Suitable sluice gates of the rising spindle type conforming to IS:3042 or sluice valve conforming to IS:780 shall be provided in the drain chamber.

8.3 A minimum of 300mm free board shall be provided for the basin over the maximum design water level. Top of the basin shall be dept 500 mm above the surrounding grade level.

8.4 Each compartment of the basin shall be provided with a concrete channel

for outlet of cold water. Cold water outlet channels shall be provided with the stoplogs and screens.

8.5 Stoplogs shall be fabricated out of structural steel plate and rolled sections and provided with rubber seals to prevent leakage. Stoplogs shall be hot dip galvanised and provided with etch primer and bituminous paint. 8.6 Screens shall be out of 8 gauge 25mm clear opening GI crimped wire

netting welded to frame of structural steel section/flats. Screens shall be hot dip galvanised and provided with etch primer and bituminous painting. Two numbers of screens shall be supplied per tower.

8.7 Suitable arrangement of monorails with hoist shall be provided for handling

stoplogs and screens.

8.8 The basin walls and floor slab, outlet channels shall be of reinforced concrete construction. The design and construction of these water retaining structures shall be in accordance with IS:456 in limit state design with a limiting crack width of 0.1mm with provision of construction/contraction and




SECTION: D4.6 g

expansion joints. Minimum thickness of structural concrete elements shall be 230mm.

8.9 The basin and channel walls shall be designed for a minimum surcharge

load of 15 kN /sq.m. to allow for construction plant operating in the vicinity. 8.10 External pressure due to earth and ground water shall not be relied upon to reduce the effect of the internal water pressure, but account shall be taken of the ground water pressure when considering buoyancy or stresses in the empty water retaining structure. 8.11 Construction of the basin and channel shall be watertight with the provision of 150mm wide approved quality PVC ribbed water stops at all construction joints and expansion joints. 8.12 The water retaining structures shall be tested for water-tightness in

accordance with IS:3370, without the backfill. Any rectification measures required to satisfy the test criteria shall be executed by the CONTRACTOR at his own cost all as per the directions of the OWNER.

9.0 FILL 9.1 Type and material of fill shall be as indicated in the Mechanical section of

this document. 9.2 The fill shall be adequately supported to minimise the sag, possibility of

dislodgement and damage as a consequence of induced vibration in the fill.

9.3 In case of film type of fill, the supporting hanger rods / tubes shall be of stainless steel conforming to ASTM 316 L.

10.0 FILL SUPPORTING STRUCTURE

10.1 Fill supporting structure with its foundation shall be of reinforced concrete construction.

10.2 Fill supporting structure, where formed of precast concrete units, shall be made stable by the use of either bolted, cast-in-situ or glued joints. Members of precast concrete structure shall be either pre-stressed or reinforced concrete units. Where bolts are used for permanent connections, they shall be of a material highly resistant to corrosion or fully protected by embedment or coating.

10.3 The columns and beams supporting the fill shall be adequately braced in all directions. The design of all members shall be checked for resistance to buckling.




10.4 The stability of the fill support structure shall be checked for its capacity to resist a horizontal force of 2% of self-weight, the fill and supporting structure, assumed to act horizontally in any direction. The structure shall also be checked for the appropriate earthquake loading as applicable. 10.5 During erection, care shall be taken to ensure the stability of the potentially

unstable, partially completed structure.

10.6 The fill support structure members shall be designed to cater for the likely loads to be imposed thereon, including:

a) temporary loadings they are subjected to during handling,

transportation and erection at normal design stresses.

b) loading due to scaffolding for the erection crew if so envisaged to be supported.

c) loading of personnel during maintenance of pipe work and sprinkler

system. The appropriate parts of the pack support structure shall be designed to support a point load of 1.5 kN at any position.

10.7 Reinforced concrete members shall be designed for self-weight and

permanent loadings by limit state method with a limiting crack width of 0.1mm as per IS:456.

11.0 PAINTING TO CONCRETE SURFACES 11.1 Waterproof bituminous paint conforming to IS:9862 shall be provided to

concrete surfaces in the area specified herein below:

i) Basin floor ii) Internal and external surface of basin walls. iii) Fill and louvre supporting columns and beams ( all surfaces ) iv) Lateral and external surfaces of louvres. v) All surfaces of fill. vi) Hot water channel / basin vii) Internal surface of fan stack viii) Underside of fan deck roof slab ix) Any other concrete surface in contact with water or subject to water spray or subjected to alternate wetting and drying.

11.2 The preparation of concrete surface for painting shall conform to IS:2395 ( Part-I ). For new surface, it is preferable that the surface left unpainted for as long as possible to allow drying. Before painting, the surface shall be thoroughly brushed to remove all dirt and remains of loose or powdered materials.




SECTION: D4.6 g

11.3 Painting shall consist of one coat of primer conforming to IS:9862 and two coats of bituminous paint conforming to IS:3384. Rate of application of paint shall be so as to give a dry film thickness of 75 microns per coat and shall be to the satisfaction of OWNER. Manufacturer’s instructions for application of paint shall be strictly followed.

11.4 All other exposed concrete surfaces shall be given one coat of cement wash after the surfaces are rubbed down suitably and as approved by the OWNER.

12.0 HAND RAILS

12.1 Hand railing shall be provided at the edges of platforms, landing slabs, stairs and walkways.

12.2 Hand railing shall be hot dip galvanised construction out of 50 mm NB pipes of medium class conforming to IS: 1161 with threaded ends and necessary bends, tees, sockets etc.

12.3 Hand railing shall be 1000 mm high with two horizontal rails, one at 500 mm and another at 1000 mm above the base level along with vertical spaced at not more than 2000 mm centres.

12.4 A toe protection plate of 65 x 8 mm shall be provided for all hand railing. 12.5 Galvanised hand rail shall be given a coat of etching primer as per IS:5666

and two coats of bituminous paints as per IS:9862 for further protection

13.0 MISCELLANEOUS REQUIREMENTS

13.1 Arrangement of water distribution system shall permit a satisfactory distribution of water over the whole area of the tower at all reasonable loads. Hot water inlet pipe shall conform to the requirement of Class I of IS:3589 and steel used shall conform to IS:2062. Distribution troughs / pipes shall independently supported from the structures and shall be easily removable. Provision shall also be made for easy flushing and cleaning of all troughs / pipes.

13.2 Beams supporting fan shall be checked to satisfy dynamic adequacy as per provisions of IS:2974.

13.3 All round the Cold water basin, plinth protection in PCC 1:2:4, 100 mm thick shall be provided for a width of 1000 mm sloping away from the basin. Dry rubble soling of 150 mm thick shall be provided below the concrete paving. 14.0 PERFORMANCE TESTING




SECTION: D4.6 g

14.1 Procedure for performance testing and penalty for not satisfying guaranteed performance are described in Mechanical section of this document.

15.0 ELECTRICAL REQUIREMENT

All electrical requirements such as lighting, lightning protection, earthing etc. are covered in the electrical section of this document.



PART H - STEEL STACK 1.0 SCOPE

SECTION: D 4.6h

This section of the specification covers the general requirements of design, material and construction of steel stack including all connected civil and structural works. Requirement of electrical works is covered under electrical section of this document.

2.0 MATERIALS

2.1 Steel Stack shall be of carbon steel conforming to IS 1079 of grade st 42 having tensile strength of 410 - 490 N/mm2.

2.2 Stainless steel liner shall conform to grade AISI 316 l of minimum 5 mm thick.

3.0 DESIGN

3.1 The design and construction of the steel stack shall conform in every respect to boiler and factory inspector’s regulation, civil aviation authority regulations and all other local and state regulations. The basic dimension of the chimney such as exit diameter of the flue, height of the flue need for liner etc. shall be decided based on the temperature, quality and quantity of flue gas, draft requirement, pollution control regulation etc. which are covered under the mechanical section of this specification.

3.2 The steel stack shall be designed to withstand the load combination as

specified in clause 6.5 of IS 6533. 3.3 A live load of 300 kg/m2 shall be considered on each platform. 3.4 Additional loads acting vertically and horizontally at the flue opening from the

gas duct shall be considered appropriately. 3.5 The stack shall be so designed that the stresses do not exceed the maximum permissible stresses as specified in IS 6533, modified to take into account temperature effect.

3.6 Corrosion allowance shall be provided, as per IS 6533 assuming design life of 20 years. Minimum thickness of windshield shall not be less than 6 mm. 3.7 Maximum deflection of the stack due to static wind load shall not exceed 1/200 of the unsupported length of the chimney. Deflections shall be calculated considering reduced thickness of the shell after deducting for corrosion allowance. 3.8 The stresses due to P-™ effect shall also be investigated and shall be added

to those arising out of other load combination.



PART H - STEEL STACK SECTION: D 4.6h

3.9 A clear gap of 150 mm shall be provided between wind shield and liner for heat insulation.

3.10 Liner shall be supported on galvanized steel members supported from windshields. These steel members shall not transfer any moment on to the windshield. These support shall be provided at an interval of 10 meters and shall be designed as per IS 800. 3.11 A stiffening ring shall be provided at the junction of the straight and tapered section of chimney. Adequate stiffening ring shall be provided to maintain circular shape and to minimize local effect. 3.12 The windshield shall be provided with helical strakes for the top one-third height of the chimney to prevent cross wind oscillation. Corrosion allowance shall be considered for the design of strakes. 3.13 The base plates and holding down bolts shall be adequate to resist the load, moments and reactions between the shell and the foundations generally satisfying the requirement of IS 800 and IS 6933. Anchor bolt shall be made 3 mm large in diameter than the dimension computed to satisfy the stress level.

3.14 Holding down bolts shall be provided with mechanical anchorage in-situ the foundation pedestal. Pockets for foundation bolt will not be permitted. Grade of concrete for foundation shall be a minimum of M25.

4.0 INSULATION

4.1 In the case of individual stacks windshield shall be insulated externally to a height of 2500 mm from the grade level/platform level.

4.2 Insulation shall be mineral wool slabs conforming to IS 8183 with a maximum coefficient of thermal conductivity of 0.06 Kcal/m/hour oC at a mean temperature of 150oC. The density of insulation shall not be less than 80 kg/cum.

4.3 The insulation thickness shall be so chosen as to limit the cold face temperature to 45oC. But in no case the thickness of insulation shall be less than 50 mm consisting of two slabs of 25 mm thick with staggered joint. 4.4 Insulation shall be lightly secured to the external surface by impaling them to studs welded to the shell and circular speed washers provided on the studs. Further the insulation shall be wrapped round with 20G galvanised wire mesh with 25 mm hexagonal pattern conforming to IS 3150. The mesh shall be bound and tied in place with 16G GI wires at 300 mm centre. The mesh shall be protected externally by 1 mm thick aluminum sheathing.



PART H - STEEL STACK 5.0 ACCESSORIES

5.1 Platforms

SECTION: D 4.6h

A maximum of 3 platforms shall be provided for individual strakes one near the top, one about 2 meter below the commencement of strakes, and one near flue gas duct entry. The platform shall be of steel brackets and galvanised gratings minimum with 1000 clear wide and shall be provided with 1350 high pipe handrails with 3 horizontal and toe protection plate.

5.2 Ladders

Individual chimney shall be provided with hot dip galvanized steel ladder externally with access to intermediate main platforms and also resting platforms in between. The ladder shall be provided on opposite sides at each main platform. Even in between the ladder shall be staggered at resting platform which shall be provided at a maximum spacing of 5 meters.

Ladder shall be made of 75 mm 8 mm flats spaced 400 mm apart with 20 mm dia rungs spaced 300 mm centre. The ladder shall be provided with suitable bracket support from the shell at a maximum spacing of 1200 mm and shall be constructed by bolting together ladder section fabricated at ground level. A minimum distance of 250 mm shall be maintained from the face of the chimney shell to the rungs. Ladder shall be provided with safety cage made up of galvanized steel flats starting from a height of 2100 mm from ground or landing level. Ladder shall also be provided with ladder safety device consisting of two sets of safety sleeves and safety belts. The device shall be from approved and proven manufacturer. The ladder shall be designed to support a live load of 175 kg at any location.

5.3 PAINTERS TROLLEY

A painter trolley shall be provided on the outside of the chimney near the top. 5.4 DOORS

An access door shall be provided near the base to the inside of the chimney for the purpose of inspection inside the chimney and also for ash removal. Minimum clear dimension of the door shall be 1000 x 2000 mm. The door shall be flush welded construction 45 mm thick with two skin plates of 18G with heat insulation in between. The door shall be hinged and shall be provided with locking device in addition to studs with wing nut. The door shall be painted with 3 coats of approved acid and heat resistant period.



PART H - STEEL STACK 5.5 COPING AND CAP

SECTION: D 4.6h

CONTRACTOR shall design, supply and fix suitable coping angles and Grey cast iron cap as the top of the stacks to cover the air gap.

5.6 ELECTRICAL ACCESSORIES

Specification for electrical requirement such as, aviation warning lamps, lightning protective system etc. are covered in the electrical section of the document.

6 REINFORCED CONCRETE AND ALLIED WORK

6.1 Foundation for the chimney shall be taken a minimum 3 m below the existing grade level and a minimum 2 m into virgin ground level. Foundation shall be of block type and of concrete grade M25. It shall be ensured that all the foundation bolts are correctly located prior to and during concreting.

6.2 When chimney supporting pedestal is of annular ring the portion inside shall be provided with minimum 150 mm thick RCC grade slab of M20 grade concrete above 50 mm PCC 1:4:8 laid over 230 mm rubble soling over well compacted soil. 6.3 Similar grade slab shall be provided outside the chimney also to extend 3

meter all round. 6.4 Inside the chimney the grade slab shall be provided with acid resistant brick

lining and proper drains with AR tiling shall be provided to take the water outside the chimney

7 FABRICATION AND ERECTION 7.2 All fabrication and erection work in general conform to IS 800 and IS

6533.

7.3 All joints shall be buttwelded with suitable edge preparation. 7.4 All steel plates shall be rolled accurately to proper curvature so as to obtain a

true cylindrical or conical shell as required. Bending of plates shall be only by plate bending machine.

7.5 Welding shall conform in all aspects to IS 816 and IS 9595. 8.0 CONSTRUCTION TOLERANCE



PART H - STEEL STACK SECTION: D 4.6h

8.1 The difference between the maximum and minimum internal diameter of shells measured at any one cross section shall not exceed 1% of nominal diameter or 25 mm whichever is lower.

8.2 After erection, the departure of the stack from vertical at any level shall not exceed 1/1000 of the height of that particular section. 9.0 INSPECTION OF WELDS

Inspection in general shall conform to clause 8.2 of Part D steel structure under section VI of the document subject to the following modifications.

(a) 100% of the vertical buttwelds and 10% of all horizontal buttwelds shall

be inspection by radiography.

(b) 100% of root welds for butt welding shall be tested by dye penetration test after back gouging.

(c) All such inspection shall be conducted in the presence of OWNER’s

representative. 10.0 PAINTING 10.1 Refer section D 4.6d (Part-D Structural steel chapter)



SECTION: D 4.6i

PART I - CODES, STANDARDS & REFERENCES

1.0 IS CODES AND REFERENCES

1.1. Reference to only some of the codes in this document and various clauses of design criteria shall not limit or restrict the scope or applicability of other relevant codes. It shall be ensured that all other codes relevant to a specific job, in addition to those already mentioned, are followed wherever applicable.

1.2. The Codes and Standards listed below are applicable for the design and construction of structures and buildings in general. Codes and Standards applicable for specific design and construction are listed elsewhere in reference sections.

1.3. Specifications for materials supplied from India shall follow the Indian Standard Specifications. 1.4. Field and laboratory testing procedures for materials shall follow Indian standard specifications.

1.5. All the Indian Standards referred to shall be the latest revision (including all amendments issued thereto) on the date of opening of the price bid. 1.6. Reference to only some of the codes in this document and various clauses of design criteria shall not limit or restrict the scope or applicability of other relevant codes. It shall be ensured that all other codes relevant to a specific job, in addition to those already mentioned, are followed wherever applicable. 1.7. Where British / American / DIN or other codes and standards are referred to in this document, equivalent Indian Standards may be substituted if available.

1.8. In case of any deviation / conflict between provisions of IS codes and the design criteria, the provisions that are more stringent shall be followed unless specifically directed otherwise.

1.9. The Codes and Standards listed below are applicable for the design and construction of structures and buildings in general. Codes and Standards applicable for specific design and construction are listed elsewhere in reference sections. 1.10. Specifications for materials supplied from India shall follow the Indian

Standard Specifications.

1.11. Field and laboratory testing procedures for materials follow Indian Standard Specifications.

1.12. Working stress design can be used as alternative but the approval of OWNER is a prerequisite.



SECTION: D 4.6i


2.0 LOADS

IS:875 Code of Practice for design loads (other than earthquake)

for Buildings and structure ( All parts )

IS:1911 Schedule of unit weights of building materials

IS:1893 Criteria for earthquake resistant design of structure 3.0 FOUNDATIONS

IS:1080 Code of Practice for design and construction of shallow

foundations on soils ( other than raft, ring and shell )

IS:1904 Code of Practice for design and construction of foundations in

soils general requirement

IS:2950 Code of Practice for design and construction of raft foundations

IS:2974 Code of Practice for design and construction of machine

foundations ( all parts )

IS:8009 Code of Practice for calculation of settlement of foundations:

( All parts )

IS:11089 Code of Practice for design and construction of ring foundation 4.0 RCC

IS:456 Code of Practice for plain and reinforced concrete

IS:458 Specification for precast concrete pipes

IS:3370 Code of Practice for concrete structures for the storage of

liquids: ( All parts )

IS:3414 Code of Practice for design and installation of joints in

buildings

IS:3935 Code of Practice for composite construction

IS:4326 Code of Practice for earthquake resistant design and

construction of buildings



SECTION: D 4.6i


IS:4995 Criteria for design of reinforced concrete bins for storage of

granular ( all parts ) and powdery materials

IS:4998 Criteria for design of reinforced concrete chimneys: ( All parts)

IS:5525 Recommendation for detailing of reinforced concrete works

IS:1786 Specification for high strength deformed steel bars and wires

for concrete reinforcement

IS:10262 Recommended guidelines for concrete mix design

IS:11384 Code of Practice for composite construction in structural steel

and concrete

IS: 1893 (Part-1) Criteria for earthquake resistant design of structures (

General provisions and building.

IS: 1893 (Part-4) Criteria for earthquake resistant design of structures (

Industrial structures including stack-like structures).

IS 13920 : Ductile Detailing of reinforced reinforced concrete structures

subjected to seismic forces 5.0 STRUCTURAL STEEL

IS:800 Code of Practice for general construction in steel

IS:802 Code of Practice for use of structural steel in overhead

transmission line towers: (All parts)

IS:806 Code of Practice for use of steel tubes in general building

construction

IS:808 Dimensions for hot rolled steel beam, column channel and

angle section

IS:813 Scheme of symbols for welding

IS:816 Code of Practice for use of metal arc welding for general

construction in mild steel

IS:1024 Code of Practice for use of welding in bridges and structures

subjected to dynamic loading



SECTION: D 4.6i


IS:1161 Steel tubes for structural purposes

IS:2062 Structural steel ( fusion welding quality )

IS:4000 High Strength bolts in steel structures - Code of Practice

IS:7215 Tolerances for fabrication of steel structures

IS:8640 Recommendations for dimensional parameters for industrial

building

IS:9178 Criteria for design of steel bins for storage of bulk material

( all parts )

IS:9595 Recommendation for Metal arc welding of carbon and carbon

manganese steel

IS:12843 Tolerances for erection of steel structures 6.0 MISCELLANEOUS

IS:1038 Specification for steel doors, windows and ventilators

IS:1172 Code of basic requirements for water supply, drainage and

sanitation

IS:1346 Code of Practice for water proofing of roofs with bitumen felts

IS:1742 Code of Practice for building drainage

IS:1905 Code of Practice for structural use of unreinforced masonry

IS:2210 Criteria for design of reinforced concrete shell structures and

folded plates

IS:2470 Code of Practice for installation of septic tank:

( part 1 ) Design criteria and construction

( part 2 ) Secondary treatment and disposal of septic tank effluent

IS:3067 Code of Practice for general design details and preparatory

works for damp proofing and water proofing of buildings

SP:6 Handbook for structural engineers ( all parts )

SP:7 National Building Code of India

SP:16 Design Aids for reinforced concrete to IS:456-1978

SP:20 Handbook on masonry design and construction



SECTION: D 4.6i


SP:22 Explanatory handbook on codes for earthquake engineering (

IS:1982-1975 and IS:4326-1976 )

SP:24 Explanatory handbook on Indian Standard code of Practice for

plain and reinforced concrete

SP:25 Handbook on causes and prevention of cracks in buildings

SP:32 Handbook on functional requirements of industrial buildings

SP:34 Handbook of concrete reinforcement and detailing (SCIP)

IRC:37 Guidelines for design of flexible pavements

IRC:73 Geometric design of roads

Bridge rules of Government of India, Ministry of Railways (

Railway Board )

BS:4485 Structural design of Cooling Towers (part 4)

section: d4.1 civil works - general general · section: d4.1 1. this specification is to cover the...

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