UNIT – 1 STRUCTURAL SYSTEMS FOR TALL BUILDINGS SYSTEMS IN STEEL

General Considerations:

Simple geometrical balanced shape and form are more suitable for tall buildings. Avoid unsymmetrical, unbalanced shape and form, when unavoidable divide into simple

symmetrical shape form with construction joints. As far as possible, attempt should be to maintain without allowing shifting of center of gravity.

Wind Load:

Strong winds (>80km/hr) are normally associated with cyclones, thunder and rigorous monsoon. The thrust on the building façade is directly proportionate to the height of the building. It has been observed that wind pressure at 300 height is 38% more than the wind pressure experienced at 150m height.

Wind pressure (p) = kv2

Where k = constant; in normal condition k=0.006; v= velocity

Wind pressure of 200kg/m2 corresponds to approximately 180km/hr wind velocity

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East coast in India – average wind pressure is 200 kg /m2. Compared to west coast- wind pressure is 100 -150 kg /m2.

In the rest of the country it is about or less than that of 60kg/m2.

Effect of the wind will be in the form of horizontal thrust producing cantilever effect. Structural designers have developed various methods to counter horizontal thrust and shear due to wind and seismic forces.

Structural system in steel

1. BEAM –COLUMN FRAME (also called rigid frame)2. VERTICAL SHEAR TRUSS3. SHEAR TRUSS FRAME INTERACTION 4. SHEAR TRUSS FRAME INTERACTION WITH RIGID BELT5. FRAMED TUBE6. BUNDLED TUBE SYSTEM7. COLUMN –DIAGONAL TRUSS TUBE SYSTEM

BEAM COLUMN FRAME

The early sky scrapers were built using this structural system in steel. The beam and column type of structural frame had become a strong innovation in late 19th

century and continued to be popular till 2nd world war (1940) In this system, the entire horizontal load is carried by steel frame work. The joints between columns and beams are made rigid by suitable methods to carry the bending

stress due to horizontal load.

Modern materials:

Ductility: Under force to regain back its shape

RCC: rigid

Materials : Steel used for frame; RCC ; composite RCC {used for tall structures}

Fibre concreteL Along with RCC, some fibers, fiber reinforced composite concrete basically RCC is a brittle material with limited ductility. In tall buildings or super high rise structures, ductility is one of the important and major characteristic material should have which is used for structural frame. Throughout the world, research is going on by using concrete with other composite materials for eg; concrete with metal hollow tubes and also with fibre reinforced composites.

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Theses fibres can be mixed with concrete along with ingredients and can also be applied or glued on surfaces depending on the situations or the surface that will be subjected to tensile forces.

Required quantity of steel used for strength and takes care of tensile forces.

Mild steel – takes both tensile and compressive forces – not brittle. Both material’s co-efficient of expansion and contraction is relatively same.

Fibres: In cement based ……….as reinforcement fibres of different materials are mixed and after drying and setting the member is subject to various types of testing for its crushing strength , tensile strength and its behavior against torsion and shear.

Concrete as such is in its pure form is brittle and highly non-homogenous. Reinforcement fibres are relatively ductile. Many types of fibres like steel fibres, carbon fibres, basalt fibres etc. for technical reason, after conducting different tests and lab experiments, volume of fibre is generally less than 3%. Added advantage of fibres is fibres also act as crack arrestors due to high amount of toughness (parallel to mud or straw)

Pulled out fibres controls crack propagation. For more toughness and durability fibre with polymers in various forms and combinations are used. This also reduces deficiency of cement based materials (deficiencies like brittleness, low tensile strength, less resistance to corrosion etc.)

In addition to fibre based reinforced composite concrete some other materials are also being developed for use in buildings and other types of tall structures. This includes polymer cement concrete, super plasticized concrete, sulphur impregnated concrete, ultra high strength concrete (M40,M50, M60)

1:1.5:3; 1:3:6; 1:2:4(M 15)

Ultra cement glass fiber reinforced concrete and roller compacted concrete.

Pre-fabricated system of construction.

Facts about tall buildings.

Precast, fabrication system

High rise buildings or tall buildings up to height of 200 -300 m are referred as tall buildings High rise buildings between 300- 600m are called super tall buildings High rise buildings with height more that 600m are called mega tall buildings. Up to 2011, the sum total of ht. of all buildings – 21642m Up to year 2000, 85% floor spaces in tall buildings were used by offices. 2013- only 43 % of the space were occupied by offices 32 % - Mixed use

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17% - Residential 8% - Hotels

Among all the tall buildings in the world about 20% out of 100 tallest buildings are located in North America (Canada also)About 45% buildings are located in Asia50% in chinaThe top 2 tallest buildings are located in middle of east.Bhurj Kahlifa – Under construction, Saudi Arabia339m tall mercury city tower is more than a km long in Moscow- tallest building in Europe.The kingdom tower in Jeddah with height of 1000m plus will be tallest building likely to be completed in 2018.Bhurj Kahlifa, the present tallest building in the world can hold 35000 people at any given time. No. of windows 24348 covering the area of 1019845 sq.mThe vertical wind turbine/ wind turbines / wind …………………….. Generation provided in shangai towers-270Bhurj Kahlifa –length of sewage life is zero.Water transported by two trucks. 7244 photovoltaic cells/panels cover the entire of façade of CIS tower in Manchester UK.This reduces 100 tons of co2 emissions/annum.

BUNDLED TUBE SYSTEM

With the future need of taller buildings, it is felt that use of the framed tube as well as the column diagonal truss tube may be used in a modular combination to create larger tube envelope. In a tall building with extremely large floor area, the exterior column system are place very close to each other , comprising only a smaller percentage of the total number of columns . Therefore in such a building, to use an exterior tube systems would result in loss of advantages which might be gained with the participation of interior columns. This problem could be overcome by arranging all columns on exterior face as well as interior columns into various configurations so as to act as bundle of tubes. For large buildings of extreme heights, one can even provide mega modules of columns, diagonal truss tubes to take care and resist all possible horizontal thrust.

The first building to use this system is the 110 storey Seers towers in Chicago (by 50m skedmore owings and merill). This building has mega module framed tubes at 22.86m square arranged in three rows both ways with column spacing 4.57m.

Tha architectural site benefits of this system have been effectively utilized by allowing termination of each module or combination of module at different levels. It helps in maintaining center of gravity without any loss of structural integrity.

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STRUCTURAL SYSTEMS IN CONCRETE (RCC)

1. Beam Column frameThe basic concept of structural design of tall buildings adopting systems in concrete is almost same as in case of steel and whatever is discussed with steel frame and also applicable with RCC.

2. Shear WallIn this system, the total horizontal shear is resisted by a solid vertical wall which is designed as a vertical cantilever beam. The shear due to wind and other horizontal forces are maximum near the base and decreases at upper levels. So it is also possible to curtail the shear wall at certain levels.Eg; Air India building- Mumbai Tata Centre –Kolkata

The most convenient place to locate shear wall is to centrally locate it as an enclosure containing staircases, lifts etc. Shear walls can also be conveniently provided on external facades. The advantages of providing shear wall as enclosure around centrally located service core, is the high concentration of dead load due to staircase weight, machine room load etc. This reduces the eccentricity of horizontal thrust. Care should be taken to see that shear walls are not damaged by ignorant occupants, while carrying out alterations, particularly when the shear wall is not in common areas.

The first use of shear wall in conjunction with flat plates was started in USA. In India, this system was initially adopted in most of the sky scrapers constructed.

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3. Shear Wall Frame Interaction

This system is an improvement in the shear wall system where the heavier of the shear wall is integrated with the rigid frames with the remaining part of the structures. One of the important factors of this system is- it exists in every RCC building with shear walls whether the frame is deliberately designed for it or not, because in concrete joints are monolithic and they are cast in situ.

The first building constructed using this system is 38 storey Brunswick building constructed in 1962 - Chicago

4. Framed Tube

This is similar to system in steel

5. Tube in Tube system

This is combination of framed tube concept with shear wall frame interaction concept and gives optimum results for buildings of about 50 storeys in height. One of the good examples of this type if system is 52 storey shell Plaza building in Houston where exterior very closely placed columns (1.82m) distance are used together with a rigid shear wall core enclosing the service areas.

6. Bundled Tube System in RCC

Closely spaced columns systems are easy to build in RCC and are more economical compared to closely spaced steel structural frames. Hence bundled tube systems may be used efficiently for concrete buildings say up to height of 15 storeys.

Depth of foundation of PETRONAS Toweres in Kuala Lumpur is 162m.

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Will Tower Chicago – Total length of telephone (sears) cables 69,200 kms. Slimmest tower in the world under construction in New york 411m high – 13m wide.

Prefabricated construction Standardization (suitable for mass housing) Mass scale for using standard framework Common in East European countries Communist /Socialist thinking Modular coordination- Multiples of basic module

2. Vertical Shear truss: The horizontal load is supported by a system of central vertical cantilever truss . The most convenient place to locate this is around the service core in the center with lifts, stairs and other resources.

3. Shear Truss Frame InteractionThis system is the interaction between the above two systems. Dr. Fazlur khan, as a partner of SOM published research papers in 1960’s in which it was pointed out that a rigid frame construction combined with shear truss in the central service core can interact in a very beneficial wayPrimarily the lateral wind shear is carried by the shear truss system in the upper portion of the building and the majority of the wind shear is carried by the shear truss system. The interactive system has 2 major advantages-namely lateral drift /sway.

By this system, sway is drastically reduced to less than 50% compared to what it would be otherwise if only shear truss is used. One of the good e.g. of this system is Chicago civic center building.Distortion of the floor due to wind pressure through less significant in view of flat shaped deflected curve can also be minimized.

While the above two methods were initial developments, various other methods were also developed since 1950. To make ultra-high rise buildings, cost effective (because systems to reduce wind and earthquake loads contribute significantly towards high cost of such buildings)

4. Shear Truss Frame interaction with rigid belt truss

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Shear truss frame interaction efficiency can be further improved in terms of lateral strength and stiffness by connecting all exterior columns to interior shear truss through horizontal belt, truss or trusses at various levels.

The addition of this belt truss will increase the stiffness of the entire structures by about 30% resulting in considerable structural economy. It should be noted that the belt truss system for mid height buildings ar different levels is very useful as this neutralize the major portion of thermal movement effects on the fully / partially exposed exterior columns of the building.

5. Frame Tube

It can be shown by simple mathematical derivation that the maximum efficiency of the total structure for lateral strength and stiffness can be achieved only by making all columns connected to each other in such a way that the whole building acts as a hollow tube or a rigid box cantilevering out of the ground.

There are many practical planning and architectural difficulties in tying all the columns of the building together . however the exterior columns can be made to act together by various horizontal connections.

Within the architectural framework, keeping in mind not to affect provision of opening fenestration etc, Generally columns placed close to each other and are tied with deep spandrel beams with possibility to prove openings.This particular system was first used in 1963 for 43 storey. – Dewit Chestnut Apartment building in Chicago.

Another point to be noted in this building. It was not constructed in steel by RCC . With the use of same system, other tall buildings were constructed later on the most notable being WTC twin towers 110 storeys.

Unfortunately these building do not exist anymore. The limitation of this system is the closely spaced columns crating the framed tube may lose some of the efficiency due to the shear lag effect caused by deflection in the 2 walls parallel to the directions of horizontal forces like seismic forces and wind forces.

WATER SUPPLY IN TAL BUILDINGS

Unequal pressure

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Unequal distribution Excess wear and tear Increased maintenance Wastage of water. 75-50mm and reduce from 5 floors to 15mm Pneumatic tubing system Pressure reduction valves

WASTE DISPOSAL IN HIGHRISE BUILDINGS

Organic waste from high rise buildings High rise buildings generally have a built in vertical trash chute with openings on each or

alternative floors e.g. (midlandings) Residents dump their waste into chutes and it falls into a compactor-preferably a compactor

trolley. The trolleys are then periodically taken and emptied at the disposal points Containers usually pulled on to the truck with mechanical hocet for unloading Then in turn the truck is driven to the final disposal point

WASTE WATER MANAGEEMENT SYSTEMS

SEPTIC TANK

Septic tank is a key component of the septic system, a small-scale sewage treatment system common in areas with no connection to main sewage pipes provided by local governments or private corporations. Other components, typically mandated and/or restricted by local governments, optionally include pumps, alarms, sand filters, and clarified liquid effluent disposal means such as a septic drain field, ponds, natural stone fiber filter plants or peat moss beds.

Septic systems are a type of onsite sewage facility (OSSF). In North America, approximately 25% of the population relies on septic tanks; this can include suburbs and small towns as well as rural areas. Indianapolis is an example of a large city where many of the city's neighborhoods are still on separate septic systems.[citation needed] In Europe, septic systems are generally limited to rural areas. Since a septic system requires a drain field that uses a lot of land area, they are not suitable for densely built cities.

Advantages

Simplicity, reliability and low cost.

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Low maintenance requirements. Nutrients in waste are returned to soil. A properly designed, well-maintained system Can last for more than twenty years.

Disadvantages

Siting limitations for septic systems include Natural soil type and permeability, bedrock and groundwater elevations, and site topography. Regulations pertaining to set-backs from Water supply, lot lines, and drainage lines must be taken into account. Restrictions on the character of influent Wastewater must be included in project planning. Improperly functioning systems can introduce nitrogen, phosphorus, organic matter, and bacterial and viral pathogens into the Surrounding area and groundwater.

The term "septic" refers to the anaerobic bacterial environment that develops in the tank which decomposes or mineralizes the waste discharged into the tank. Septic tanks can be coupled with other treatment units such as bio filters or aerobic systems involving artificial forced aeration.[2]

Periodic preventive maintenance is required to remove the irreducible solids that settle and gradually fill the tank, reducing its efficiency. According to the U.S Environmental Protection Agency, in the United States it is the home owners' responsibility to maintain their septic system.[3] Those who disregard the requirement will

eventually be faced with extremely costly repairs when solids escape the tank and clog the clarified liquid effluent disposal system. A properly maintained system, on the other hand, can last for decades or possibly even a lifetime.

ANAEROBIC BAFFLE REACTOR

Aerobic digestion is a collection of processes by which microorganisms break down biodegradable material in the absence of oxygen.[1] The process is used for industrial or domestic purposes to manage waste and/or to produce fuels. Much of the

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fermentation used industrially to produce food and drink products, as well as home fermentation, uses anaerobic digestion.

Background and working principal

physical and biological (anaerobic) treatment of wastewater

integrated sedimentation chamber for pre-treatment of wastewater

alternating standing and hanging baffles

wastewater passes through the sludge to move to the next compartment

solid retention time (SRT) separated from hydraulic retention time (HRT)

high treatment rates due to enhanced contact of incoming wastewater with residual sludge and high solid retention

low sludge production

A review concerning the development, applicability and possible future application of the anaerobic baffled reactor for wastewater treatment is presented. The reactor design has been developed since the early 1980s and has several advantages over well-established systems such as the up flow anaerobic sludge blanket and the anaerobic filter. These include: better resilience to hydraulic and organic shock loadings, longer biomass retention times, lower sludge yields, and the ability to partially separate between the various phases of anaerobic catabolism. The latter causes a shift in bacterial populations allowing increased protection against toxic materials and higher resistance to changes in environmental parameters such as pH and temperature. The physical structure of the anaerobic baffled reactor enables important modifications to be made such as the insertion of an aerobic polishing stage, resulting in a reactor which is capable of treating difficult wastewaters which currently require several units, ultimately significantly reducing capital costs.

Advantages:

• extremely stable to hydraulic shock loads • high treatment performance• simple to construct and operate• no electrical requirements• low capital and operating costs, depending on economy of scale• low sludge generation• biogas can be recovered

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Disadvantages:• needs expert design• long start-up phase• needs strategy for faecal sludge management• effluent requires secondary treatment and/or appropriate discharge• clear design guidelines are not available yet

ANAEROBIC FILTER

 Sewage treatment systems, an anaerobic filter (AF) is a form of anaerobic digester. The digestion tank contains a filter medium where anaerobic microbial populations — organisms that live in the absence of oxygen — can establish themselves. Such filters are commonly employed in the treatment of waste water. These reactors are gaining in popularity versus more established aerobic waste- water treatment systems because they produce a less solid residue [1] than do other types of filter.

AdvantagesThe main advantages of anaerobic treatment are therefore that it:

is a well-known and extensively applied process; is versatile for treating both ordinary and 'difficult' wastes; is a low-energy process, making it more environmentally friendly; and Have lower running costs as a result of the low energy inputs.

Disadvantages

The main disadvantage of many anaerobic treatment processes is that they are not good at removing non-organic pollution within wastewater, such as nutrients or disease-causing micro-organisms (pathogens).

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A typical Up flow Anaerobic Sludge Blanket (UASB) digester, with a retention time of 4 to 5 hours, can be expected to remove 75% of faecal bacteria and 90% of intestinal worms from a wastewater. Such removal rates may be impressive for limiting effects of chemical pollutants, but are negligible for pathogens which still present a health hazard after reduction by several factors of ten.

All anaerobic processes provide only partial treatment and therefore require the effluent to be treated further before it can be safely released into the environment.

Anaerobic treatment consists of a sequence of activities performed by different organisms. For digestion to be effective, it should operate as a finely balanced, living system – carefully controlled and closely monitored. Disruption to the balance of the organisms can hinder treatment. Anaerobic processes work best with ‘steady’ effluents – that is, they are not good at coping with variations in the flow or composition of the wastewater stream. So for example, anaerobic processes cannot cope with ‘shock loads’ of heavy metals that may come from industrial processes or from runoff water in storms.

SAND GRAVEL FILTER

Sand filters are used for water purification. There are three main types;

1. rapid (gravity) sand filters

2. up flow sand filters

3. slow sand filters

All three methods are used extensively in the water industry throughout the world. The first two require the use of flocculants chemicals to work effectively while slow sand filters can produce very high quality water free from pathogens, taste and odour without the need for chemical aids.

A sand bed filter is a kind of depth filter. Broadly, there are two types of filter for separating particulate solids from fluids:

Surface filters, where particulates are captured on a permeable surface

Depth filters, where particulates are captured within a porous body of material.[1]

In addition, there are passive and active devices for causing solid-liquid separation such as settling tanks, self-cleaning screen filters, hydro cyclones and centrifuges.[1]

There are several kinds of depth filter, some employing fibrous material and others employing granular materials. Sand bed filters are an example of a granular loose media depth filter. They are usually used to separate small amounts (<10 parts per million or <10 g per cubic meter) of fine solids (<100 micrometers) from aqueous solutions.[2]:302-303 In addition, they are usually used to purify the fluid rather than capture the solids as a valuable material. Therefore they find most of their uses in liquid effluent (wastewater) treatment.

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UNIT – 2 TALL BUILDING FLOOR SYSTEMS

LIFT TRAFFIC ANALYSIS

• Assessment of demand • Traffic patterns (in an office building)

• Morning UP peak

• Evening DOWN peak

• Two-way traffic (lunch periods)

• Interfloor traffic

• Other considerations, e.g. ‘Flexitime’ attendance

• EE i i f l i ( d i ) estimation of population (occupant density)• Estimation of arrival rate

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LIFT TRAFFIC ANALYSIS

Estimation of quality of service of quality of service

• • Actual average passenger waiting time (AWT)• • Time between the instant of passenger arrival until the instant of the actual arrival of the lift• • Shorter the waiting time, better the service• • But cannot be measured easily

Interval of car arrivals at the main terminal

• Oft en taken to estimate the probable quality of service• A part of the evaluation of handling capacity• AWT ≈ 85% of the interval (assumed 80% car loading)

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LIFT TRAFFIC CALCULATIONS

Lift traffic calculations Based on classical formulae & results For the worst 5-min period during morning up

peak Based on a discrete digital simulation of the building, its lifts and the passenger

dynamics Such as for down peak, two-way & Interfloor traffic

Calculate up peak performance• Determine round trip time (RTT)• Time for a single lift to make a round trip• Select number of lifts (L)• Determine up peak interval (UPPINT)• Such as, <= 30 sec (good)• Determine up p g p y ( ) p peak handling capacity (UPPHC)• During the worst 5-min (300 sec) of up peak

RTT = 2 H tv + (S + 1) ts + 2 P t v p

H = average highest call reversal floor

t v = single floor transit time (s)

S = average no. of stops

ts = time consumed when stopping (s)

P = average no of passengers carried

tp = passenger transfer time (s)

UPPINT = RTT / L

• UPPHC = (300 x L x P)) / RTT

Parameters in RTT equation

• Average no. of passengers (P)• P = 0.8 x rate capacity of lift car• Average highest call reversal floor (H)

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.

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FORMULA TO CALCULATE LIFT HANDLING CAPACITY

H= 300 x Q x 100 / T x P

Where H= Handling capacity as the percentage of peak users handled in 5 min

Q = Average no. of passengers indicates (80% of capacity)

T = Waiting interval

P = Total no. of users to be handled in peak hours

Waiting Period

‘T’ = RTT / N

Where N = No. of lifts

RTT = Round Trip Time (sum of total time taken to enter, come out, closing door etc. )

Quality of Services

It is generally measured by the passenger waiting time at various sources. As per IS specification & NBC, the quality of service are acceptable when interval is classified as follows:

20 – 25 sec –excellent

30- 40 sec Fairly good

45 secs and above are considered as not satisfactory.

Note: for residential bldg.. more waiting period or interval upto 90 sec is permissible.

Various other points which require spatial considerations while planning and designing lifts services are as follows:

• At lower level could be of low speed lifts• At mid-level lift should of high speed and it is advisable to provide services at higher level with

super or high speed lifts.

NON STOPPAGE ON LOWER FLOORS

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In case of very tall buildings some elevators are meant and provided for serving only the upper floors. This saves valuable time for upper floor residence, users and occupiers. The low speed elevators are convenient for lower occupants.

STRETCHER LIFTS

At least one lift must be 2m (6’6”) long to accommodate stretcher in case of any emergency. Stretcher lift is installed in hospitals, medical centers and clinics, i.e. in buildings where escorted stretchers are to be transported.

FIRE LIFTFor all buildings taller tha 24m minimum one lift should have an independent control system from the gorund or base floor and should be high speed so as to to reach top most floor with in one min.Placing of Lift cars:There could be various arrangements possible to plan the position of lift cars keeping the main criteria that enough waiting and circulation space is available to minimize any possibility of congestion particularly during peak hours.

SERVICE CUM BAGGAGE:

In buildings that need no. of elevators (more than 3). One of the elevators should be exclusively designed to carry baggage or luggage. This is normally a slow speed elevator which ar bigger or larger gauge and with higher load capacity. Sometimes this lift is also used by service providers.

ZONING SYSTEM

In very tall buildings, the zoning systems is carried out wherein the building is divided into suitable zones. In each zone, there are local elevators catering to the need of that particular zone with various speeds. Each zone has its own lobby (sky lobby). Here the passengers or

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users could change from one zone to another zone and also from high speed lifts to local lifts. This arrangement can be compared with surface mass transit system where some stations separates local low speed and high speed trains. Sometimes double deck elevator system is also used to save floor space.

For eg: One deck could be reserved to serve even floor whereas the other deck could save odd floors.

ELEVATOR SYSTEM IN SUPE SKY SKRAPER:

In very tall buildings there are as many as more than 100 lifts. The express or the high speed lifts from the main entrance lobby with capacity of about 50 persons each serves the sky lobbies where the passengers transfers to local elevators.For Eg:

• In World Trade Centre, there were 32 express elevators and the sky lobbies were located on the 44th and 78th floors.

• The sears towers in Chicago has a similar system with 104 elevators, 14 of them are express, double decker lifts. 2 super express elevators can reach 412.5m (1353’) high sky deck in less than one minute. There are two level, sky lobbies provided at 33rd, 34th and 66th and 67th floors. There are escalators connecting these 2 levels.

FIRE SAFETY IN HIGH RISE BUILDINGS

High rise buildings when under five might result in high depth tolls, injuries and loss of property. It is the prime duty of architects and designers to incorporate available passive features during conceptual designs, detailing and construction stage. Fire danger in low rise buildings compared to high rise buildings.. Inspite of available facilities for controlling the fire, sometimes the fire brigade and fire men

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are helpless in saving human life and protecting the property as many portion of the buildings are unapproachable.

Initially the water for extinguishing fire is pumped from the tank and later on if the water availability is not enough from the hydrant which are located at suitable intervals along the road. The pipe line connects all the hydrants provided exclusively for firefighting purposes, pressure in this pipeline is increased by the local authorities in case of fire. These fire hydrants are connected with water hose by fire brigade using a special key. It is surprising that no newly developed townships are provided with water hydrants. Recently a sophisticated type of ladder is developed known as SNORKEL ladder, It has several advantages over the conventional ladder.

• It can rescue multiple persons together during fire accidents from more than the height of 35m in 80 sec with unparalleled features. In normal features , even infants and persons , injured persons can be comfortably brought down with least effort.

• In snorkel ladder 3 or even more water jets are provided in the cabin or at the top one to protect the firemen themselves within the cage or cabin and the other jets to drouse the fire with total delivery of 500 gallons per minute.

• This unit is versatile as without shifting the base, the head of the ladder could be shifted , turned and rotated from one position to another position. This ladder could reach upto the height of approximately 10 storey buildings. Another big advantage is , it could reach the desired position even in congested areas of town.

• The firemen inside the cabin and at the base can communicate and operate the ladder independently also.

• Another important feature is provided with fresh air pipeline that is supplied through cylinders at the base level. The base vehicle is also equipped with the emergency medical treatment facilities.

PROBLEMS OF HIGH RISE BUILDINGS

There could be 2 important aspects of fire safety in high-rise buildings and they can be summarized as follows:

1. This would relate to design and construction features of high rise building. The structure must remain rigid and intact during fire.

2. Smoke control is very important element in the provision of safety capability.3. There must be satisfactory system for rescuing trapped persons including safe travel distance

and provision of safe refuge areas where people could gather before they could be rescued.This would pertain to spatial appliances and equipment to be provided within the building that consist of

• Firefighting appliances and facilities within the building to help firemen operating internally.

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• Emergency communications and controls systems providing required information for occupants and fire squad such as data on fire approximately no. of trapped persons and location of fire.

• There must be adequate maintenance of all the equipment regularly and those equipment and devices must be kept in working conditions all the time.

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