Specifica a progetto verticale - Inglese (Versione 3.0c Maggio 1995)

COMPANY

Nigerian Agip Oil Company Limited JOB UNIT

PLANT LOCATION

Naoc Port-Harcourt Base Nigeria CODE 3217.46.BASG.36905

PROJECT/UNIT

New Port-Harcourt Base Power Generation Project Sheet / of

2 of 19Revisions

0

PROJECTS DEVELOPMENT/ENGINEERING DIVISIONTITLEDesign Specification for Civil/Structural Works

COMPANY

Nigerian Agip Oil Company Limited JOB UNIT

PLANT LOCATION

Naoc Port-Harcourt Base - NigeriaCODE 3217.46.BASG.36905

PROJECT/UNIT

New Port-Harcourt Base Power Generation ProjectSheet / of

1 of 19Revisions

0

PROJECTS DEVELOPMENT/ENGINEERING DIVISIONTITLEDesign Specification for Civil/Structural Works

DESIGN SPECIFICATION FOR CIVIL / STRUCTURAL WORKS

AT

NAOC PORT-HARCOURT BASE NIGERIA

022/06/12Issued For ReviewDordor H.Akano D.Omietimi R.

Rev.DateDescriptionPreparedCheckedApproved

CONTENTS

1.GENERAL

1.1Scope

1.2Environmental Data

1.3Applicable Codes, Standards and Regulations

2.DESIGN CRITERIA

2.1Design Loads

2.2Load Definitions

2.3Loads During Construction

2.4Loading Combinations

2.5Miscellaneous Loads

2.6Permissible Stresses

2.7Stability

2.8Anchor Bolts

2.9Grouting

2.10Baseplate Levels

3.STRUCTURAL STEELWORK

3.1Scope

3.2Design Methods

3.3Steel Grade

3.4Runway Beams

3.5Fireproofing (passive)4.REINFORCED CONCRETE FOUNDATIONS AND STRUCTURES

4.1Scope

4.2Design Methods

4.3Concrete

4.4Reinforcing Steel

4.5Drawings

4.6Foundations

4.7Machinery Foundations

1.GENERAL1.1ScopeThis Specification defines the loads and design criteria to be taken into account in the civil/structural design of the Civil/Structural Engineering work for the New Port-Harcourt Base Power Generation Project. These loading and design criteria shall be utilised irrespective of the material employed in the construction of the various structures.

1.2Environmental DataMinimum ambient temperature

16(C

Maximum ambient temperature

36(C

Maximum solar gained temperature

84(C

Maximum relative humidity

99%

Maximum wind speed

75 km/h

Rainfall:60min interval

92mm/h

30min interval

140mm/h

15min interval

160mm/h

1.3Applicable Codes, Standard and RegulationsThis specification is to be read in conjunction with the following British Standards or equivalent Europeans Codes, UNI, ASTM, DIN or ISO standards which shall be those current on the date of the award of this contract, including all revisions and addenda up to and including this date.

EN 1991 Action on structuresEN 1990 Basis of structural design

EN 1992 Design of concrete structures

EN 1993 Design of steel structures

BS 2853

Design and Testing of Steel Overhead Runway Beams

BS 7613(1944)

Weldable Structural Steel

BS EN 10029 (1991)Weldable Structural Steel

BS EN10113 (1993) prt 1-3Weldable Structural Steel

BS EN 10155 (1993)

Weldable Structural Steel

BS EN 10210-1 (1994)

Weldable Structural Steel

BS 4449 (1997)

Carbon Steel for the Reinforcement of Concrete

BS 4483 (1985)

Steel Fabric for the Reinforcement of Concrete

BS 4466 (1989)

Bending Dimensions and Scheduling for the

Reinforcement of Concrete

BS 6031

Earthworks

BS 8004

Foundations

BS 8007

Structural Use of Concrete for retaining

Aqueous Liquids

CP2012 Part 1

Foundations for Machinery.

DIN 4024

Supporting Structures for Rotary Machinery

Clients Specifications:

27549. VAR.CIV.FUN

Demolition Specification

27550. VAR.CIV.FUN

Site Clearing and Excavation Specification

27551. VAR.CIV.FUN

Fill Specification

27552. VAR.CIV.FUN

General Concrete Specification

27557. ROD.CIV.FUN

Road Work Specification

27563. VAR.CIV.FUN

Drainage Specification

27570. VAR.CIV.FUN

Structural Steelworks

NOTE: In the event of conflict between the requirements of this specification and the relevant supplementary specifications mentioned herein, the most stringent shall prevail.

2.DESIGN CRITERIA2.1Design LoadsFoundations and structures shall be designed to include all dead, live, test, impact, vibration, pipe, pipe expansion, thermal and friction, bundle pull, wind, transportation, lifting and erection loads and forces.

2.2Load Definitions2.2.1"Dead Load" shall be the total weight of materials forming the structural unit and all permanent attachments including insulation or casing. All loads shall be accurately computed using unit weights from BS 648. Basic dead load of equipment is to be increased by 25% to obtain design dead load.

2.2.2"Live Load" shall be the imposed load on a structure, floor, platform, walkway or stair due to operation and maintenance only, all movable and intermittent loads including:-

a)Personnel, portable machinery, tools and equipment.

b)Material to be temporarily stored during maintenance, such as equipment parts, pipe and fittings, valves.

c)Material normally stored during operation such as tools, maintenance equipment and catalyst.

Walkways, stairs and platforms for all structures shall be designed for the applied live load specified below.

Description of Structure

Live LoadOperating platforms: full load of equipment and L.L.3kN/mOperating platforms during maintenance

5kN/mWalkways and Stairways

5kN/mAreas designated for storage (minimum or as

circumstances dictate)

7.5kN/mBeams

10kN

point load in addition to other loads (not carried to supporting members).

2.2.3"Test Load" shall be the dead load of all materials forming the structural unit, plus all live loads on platforms and walkways, plus the dead load of water or other methods used for testing equipment.

2.2.4"Equipment Load" shall be the weight of machinery and/or process equipment together with dead load attachments, weight of liquid or solid materials in equipment during normal operation and including dynamic loads from pulsating and vibrating equipment and from surging fluids.

For overhead cranes loadings from impact or vibration shall be additional to gravity loadings.

2.2.5"Pipe Load" shall be the weight of all pipes, valves, fittings, insulation etc., and shall include the weight of contents during test or normal operation, whichever gives the most severe effects. An allowance for test loads of lines full of water shall be assessed individually for each case and an appropriate total test load used for design.

For piperack structures the design load shall be taken from AGIP specification 06594.VAR.GEN.PRG Section 4.0.

In the absence of specific loading, beam trusses, rafters etc., likely to support piping, shall be designed for the following minimum loads, in addition to those in clause 2.2.2:-

Up to 3m span

7.0kN per lin m

3 - 5m span

6.0kN per lin m

5.0m and over span5.0kN per lin m

All these additional loads shall be transmitted to the supporting stanchions and foundations.

2.2.6"Thermal Load" shall be the load acting upon a structure due to change in temperature of machinery or process equipment. The longitudinal thermal load on a pipeway shall be taken as 15% of the total operating vertical pipe load or 30% of any one or more lines known to act simultaneously in the same direction, whichever is the greater.

For horizontal loading refer to AGIP specification 06594.Var.Gen, section 4.3.

The horizontal force from expansion/contraction acting on members supporting exchangers and horizontal vessels shall be taken as equal to the lesser of the friction force or the force required to produce the expansion or contraction.

Friction forces shall be the empty, or operating weight times the friction co-efficient taken from the following table or for horizontal vessels, a minimum of 5.0kN per plinth whichever is the greater.

Surfaces

Friction FactorSteel to steel

0.30

PTFE to Stainless Steel

0.10

Teflon to Teflon

0.10

Steel to Concrete

0.50

2.2.7"Wind Load" shall be in accordance with EN 1991 2.2.8"Erection Load" shall be the loadings peculiar to the erection stage of the complete or any intermediate stage of completion of the structure. The effect of these loadings shall be investigated for strength and stability.

2.2.9"Seismic Load" - the site has not been designated a seismic zone.

2.2.10Surcharge Load

Surcharge from both operational and constructional traffic shall be to BS 5400 part 2, Type HA loading with a maximum wheel load of 11.43 tonnes, applied to main access road only.

Trenches shall not be considered as being laterally supported by trench covers.

For maintenance or operating condition the minimum surcharge shall be 10kN/sqm.

2.3Loads During ConstructionIn addition to the loads imposed upon the structure in its installed condition, all parts of the structure and any temporary works shall be designed to accept the loads imposed upon them during all conditions of construction and erection. In particular, extreme point loads can be introduced during the lowering of heavy equipment onto a supporting structure and also during the exact positioning (lining out and levelling) of equipment.

2.4Loading Combinations

The combinations of loads and forces shown in Table 1 shall be considered for the design of all structures, and foundations.

TABLE 1

LOADING COMBINATIONS

LoadingDesign Loads and Forces (all loads and forces are to be combined to produce the most onerous conditions)

Erection1.Dead weight of structure and foundation only (less fireproofing and piping)

2.Dead weight of equipment, less all loose internals (ladders, platforms, insulation, fireproofing).

3.Temporary loads and forces caused by erection.

4.Bundle pull where applicable.

5.Full wind on projected area exposed surface only.

Normal Operation1.Dead weight of structure and foundation plus fireproofing.

2.Dead weight of equipment, including all internals insulation and platforms supported from equipment.

3.Dead weight of piping, plus insulation.

4.Operating weight of "fluid" in equipment and piping.

5.Thermal forces.

6.Piping Anchor Forces

7.Crane loads including impact and horizontal loadings caused by surge and braking.

8.Unbalanced forces from vibrating equipment and impact.

9.Applicable live loads from platforms and walkways (except that when designing anchor bolts and checking stability against wind, no such live loads shall be included).

10.Full wind on projected area exposed surface only.

TABLE 1

LOADING COMBINATIONS (continued)Emergency Shutdown1.All loadings as listed for Normal Operation plus any abnormal loadings caused by Emergency shutdown.

Test Load1.Dead weight of structure and foundation plus fireproofing.

2.Dead weight of equipment, including all internals, insulation and platforms supported from the equipment.

3.Dead weight of piping, plus insulation.

4.Weight of water for testing, or crane test load.

5.Applicable live loads from platforms and walkways.

6.50% wind on projected area.

Loading ConditionDesign Loads and Forces (all loads and forces are to be combined to produce the most onerous conditions).

Wind Load1.Wind Loads should be analysed separately and the resulting loads and forces combined with erection, normal operating (excluding crane loads) and emergency shutdown.

2.50% of the wind load shall be combined with normal operating (with crane loads), and test load.

Blast Load *

NOT APPLICABLE1.Blast Load of 100 kN/m should be included in the structural analysis of control room only.

2.Blast Load should not be combined with other imposed loading except those which are permanent.

* Note:Blast load may be reduced after rigorous explosion load analysis is performed, subject to Clients approval.

2.5Miscellaneous Loads2.5.1Pipe AnchorsConcrete foundations for pipe anchors shall be designed to carry the loads calculated from the final stress analysis of the pipework.

2.5.2Tubular BundlesFor horizontally mounted heat exchangers in normal service the lateral force for pulling bundles is to be taken as 2.0 x weight of the bundle or 5.0 kN whichever is the greater.

The forces above are assumed to apply after the bundle has been jacked away from the shell flange and are considered to act along the centre line of the tube bundle.

2.5.3Horizontal DrumsPlinths for horizontal drums shall be designed for direct loads, plus horizontal forces due to wind, pipe thrusts and thermal forces induced by friction at vessel baseplate.

The thermal force is to be considered as 0.3 x direct operating load on the plinth from the horizontal drum it supports, or 5.0 kN per plinth whichever is the greater.

Tall piers of horizontal drums supported at a high level may alternatively be designed for the moment induced by the maximum movement of the pier due to the calculated expansion of the drum.

2.5.4Tie BeamsTie Beams where required at grade are to be checked to ensure they are capable of supporting an additional two tonne construction point load acting at any point on the span.

2.6Permissible StressesNormal soil bearing stresses may be increased for the following load combinations provided that normal stresses are not exceeded for combinations excluding the loads:-

Load

Stress Increase

Wind

25%

Test

10%

No stress increases shall be allowed for stacks, towers, tall columns, etc., where wind is the predominant loading.

2.7StabilityStability Ratio = Stabilising Moment

Overturning Moment

The minimum stability ratios shall be as follows:-

Erection condition: For dead load of a vessel or structure, acting with or without wind, the stability ratio shall be a minimum of 1.4.

All other Design Conditions: For dead and live loads acting with or without wind, the stability ratio shall be a minimum of 1.75.

2.8Anchor BoltsAnchor Bolts shall be provided by EPC Contractor or vendor for all equipment, structures etc. in accordance with drawing no. (AGIP Code) 02042 and 02044 BLD.CIV.DWG Anchor Bolts,

All bolt sleeves shall be grouted up to plinth level.

2.9GroutingThe minimum thickness of grout shall be 25mm unless otherwise specified by equipment or machinery manufacturers. Non-shrink grout having a characteristic strength of 40N/mm to be used.

Non-shrink grout has to be used for pumps and compressors (not below aircooler structures)

2.10Baseplate LevelsThe underside levels of equipment and stanchion bases shall be 300mm above high point of paving unless required otherwise by design.

3.STRUCTURAL STEELWORK3.1ScopeThis part of the specification defines the requirements for the design of structural steelwork.

3.2Design MethodsThe design shall be in accordance with BS 5950.

3.3Steel GradeFor members or structures supporting equipment or piping, all material shall be Grade 43A to BS7613 (1994), BS EN 10029 (1991), Part 1 to 3 of BS EN 10113 (1993), BS EN 10155 (1993) and BS EN 10210-1 (1994). Access platforms, flooring, ladders and handrailing shall be Grade 43A.

3.4Runway BeamsRunway beams shall be designed in accordance with BS 2853.

3.5Fireproofing (Passive)Structural members to be fireproofed shall be clearly defined on the drawings. Where expansion joints occur, a suitable detail to enable mineral wool packing shall be provided. Fire proofing detail as per AGIP Specification number 07778.OPF.SAF.PRG.

4.REINFORCED CONCRETE FOUNDATIONS AND STRUCTURES4.1ScopeThis part of the specification defines the requirements for the design of reinforced concrete foundations and structures.

4.2Design MethodsAnalysis of all concrete structures shall be performed according to the ultimate limit state design methods contained in BS 8110, Part 1. Liquid retaining structures additionally shall be analysed according to the service limit state design methods contained in BS 8110, Part 2 and BS 8007.

4.3ConcreteThe grade of concrete used in the works shall be in accordance with BS 8110 and shall be designated as follows:-

Grade 25For foundations and/or other structural works

Grade 20For area paving, cable trenches and minor miscellaneous floorings.

Grade 20For mass concrete (used for piping or electrical road crossings).

Grade 15Blinding (lean concrete).

Sulphate Resisting ConcreteWhere necessary concrete below ground level should be suitably protected against sulphate attack by the addition of sulphate resisting cement or some other suitable form of protection and the EPC Contractor is to show the full extent of such protection on his drawings.

The use of sulphate resistant cement or protection against sulphate attack will be defined according to the results of the soil investigation.

4.4Reinforcing Steel4.4.1Bar ReinforcementHot rolled, high yield, high bond bars to BS 4449 shall be used.

Bars shall be bent cold in accordance with BS 4466 with appropriate shape codes.

4.4.2Mesh ReinforcementWelded steel wire fabric reinforcement shall be to BS 4483.

4.4.3Reinforcement Against ShrinkageShrinkage in all structural members where the minimum thickness in a cross-section exceeds 300mm shall be assessed and appropriate reinforcement provided. Sufficient reinforcement shall be provided such that the reinforcement does not yield due to cracks resulting from early age and thermal shrinkage. Such reinforcement should be distributed in accordance with the crack width requirements of BS8110.

This shall also apply to foundations where the minimum thickness in a cross-section exceeds 1000mm.

4.5DrawingsThe drawings shall be to a high aesthetic standard throughout, particularly with regard to dimensions, lines, planes and levels.

Each drawing for concrete work shall indicate the surface finishes to be produced, clearly defining areas of different finish.

The top surfaces of all foundations, beds and plinths shall be absolutely level unless required otherwise for a specific purpose.

Bending schedules shall be produced for each foundation or structure and identified with an unique tag mark.

4.6Foundations4.6.1Formations of FoundationsAny material which may adversely affect the stability of any part of the works is to be dug out and the area backfilled with suitable material.

Backfilling below formations for foundations, pits, concrete trenches and the like shall be in concrete Grade C15.

Provisions should be made in the design and details to avoid ingress of water to the foundation soils during and after construction of the substructures.

4.6.2Foundations Design

The Contractor shall provide foundation design which ensure that equipment, structures, buildings etc., are fully supported and stable.

The design of foundations shall be sufficient to ensure that total settlement does not exceed 20mm and differential settlement does not exceed 10mm.

In certain instances more stringent settlement requirements may apply in order to avoid exceeding allowable stresses on pipework, equipment etc.

Spread FoundationsDue to nature of the soil, the use of spread foundation should be avoided except for structures of the secondary importance (i.e.; sheds, access platforms etc.)

When used the foundations shall be designed for a net bearing pressure of 60 kn/m2 .

Piled Foundations

Pile foundations should be used to support any superstructures of major importance.

It is recommended that in built-up areas bored piles should be adopted.

The minimum spacing of piles shall be 3 x pile diameter and the minimum edge distance from the centre line of the pile to edge of pile cap shall be 1 x pile diameter. Pile types will be confirmed after the soil investigation report is made available.

Pile caps shall be a minimum of 900mm thickness.

SlidingThe safety factor against sliding shall be taken as 2.0 and in complying with the requirements it shall be necessary to ascertain that the resulting pressures and shear forces to be transferred from the foundations to the supporting soil shall not be greater than that permissible.

4.7Machinery Foundations4.7.1GeneralFoundations and supporting structures for machines producing periodic disturbing forces shall be designed to take account of all possible out-of-balance dynamic forces and care taken to prevent resonance occurring due to the natural frequencies of the soil/ foundation/support system being close to the machine operating speeds. Amplitudes of vibration should be limited to machine manufacturer recommendations.

4.7.2Isolation of FoundationsFoundations subject to vibration shall be properly isolated from adjacent foundations and structures.

4.7.3Design StressesIn preparing the design, consideration is to be given to reduce the normally permitted stresses for soils, concrete and steel. All reinforcing bars shall be of a deformed high bond type and incorporate a hook or bend at each end where possible and binders or stirrups shall have their ends bent to a minimum included angle of 45.

4.7.4Foundation RatioThe minimum ratio of weight of concrete to weight of machines for minor equipment items i.e. pumps etc. shall be:-

a)Centrifugal machines ratio 3:1

b)Reciprocating machines ratio 4:1

c)Machine manufacturers requirements

4.7.5Centrifugal Machines FoundationsThe design of the foundations shall be in accordance with BS CP 2012 and "Deutsche Normen DIN 4024" but the out of balance forces shall be calculated in accordance with "Deutsche Normen DIN 4024".

4.7.6Reciprocating Machines Foundations

The design of right block foundations for reciprocating machines shall be in accordance with BS CP 2012.

Vibration AnalysisThe vibration analysis for all compressors shall be as recommended in BS CP 2012. The pile stiffnesses i.e. horizontal and vertical used in the analysis shall be based upon the results from the in-situ dynamic pile tests, such tests being executed on piles having the same characteristics as those supporting the foundations.

The exciting forces used shall be the maximum value and shall be defined as either:-

1.The manufacturer's recommended value occurring during the lifetime of the equipment.

2.The value as computed from the Codes of Practice listed above.

All natural frequencies below twice the operating frequencies of reciprocating equipment and below 1.5 times the operating frequencies of rotating equipment shall be calculated. Where the natural frequency lies between 0.35 and 1.5 times any operating frequency, resonance shall be assumed to occur, and amplitudes calculated using an estimated dampening value. Dampening of the equipment shall be effected by proprietary anti-vibration mountings supplied by Construction Contractor or calculation shall be made to show that the soil can exert the required dampening of the foundation system.

Allowable AmplitudesThe allowable amplitudes shall not exceed the lower of the following values:-

1.The maximum allowed by the manufacturer of the equipment.

2.The amplitude of vibration of the foundations to rotary and reciprocating machines shall not exceed the limit defined by Line ABB' in Fig. 3 of BS CP 2012.

3.The amplitude in rotary machines which causes the effective velocity of vibration to exceed 2mm/sec.

Static DeformationsThe static deformations of the foundations for rotary equipment shall be within the limits defined by the machine manufacturer. Where applicable, the effects of deformations caused by the following shall also be investigated:-

1.Shrinkage and creep of the concrete.

2.Temperature effects caused by radiation or convection of heat or cold generated by machinery, piping and ducting.

3.Elastic deformations caused by changing vapour pressure in the condensers.

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This document is the property of NAOC who will safeguard its rights according to the civil and penal provisions of the law.