Presented by : Aazam Nirban

Civil Engineering Department

T. Y. Civil

3105

Presentation on BURJ KHALIFA

The Burj Khalifa is the ever built tallest

man made structure.

This tower rises in the sky to 828m

carrying 162 floors.

The Burj khalifa took 6years for itsconstruction

and was completed in the year 2010.

For erecting this city in the sky several

new technologies had to be used.

INTRODUCTION

The soil stratum of Dubai is very week so they had to excavate up to 50m deep to get a hard rock structure

But the rock that they found was fragile and saturated with ground water

So that any hole made

will be cured immediately

EXCAVATION

The engineers filled this with a viscous polymer slurry

This pushes the rock and the ground water to the edges of the boreholes to keep it open

This slurry is denser than water and liter than concrete, so that when concrete is pumped the concrete displaces the fluid and forms the

foundation.

194 piles were constructed

for avoiding the sinking of

this structure.

EXCAVATION Cont.

The casting of the whole structure is mainly done by two materials

1. Concrete

2. Steel

Over 30,000 tons of steel were used

About 250,000 m2 concrete was also used

The reinforced concrete acts as the backbone of the whole structure

CASTING OF THE STRUCTURE

The Burj can accommodate about 35,000 people at a time

Consist of 57 elevators and 8 escalators

The biggest elevator carries about 46 people at a time

These elevators travel at a speed of 35km/hr

The Burj has a service/firemans elevator which have a capacity to hold about 5,500kg

And this is the worlds tallest service elevator.

ELEVATORS AND ESCALATORS

The Burj is cladded with high-tech glass which forms as a curtain wall

If the whole cladding has to be done with high-tech glass which will cost about 100 million dollars

CLADDING OF THE TOWER

The cladding should withstand the heavy sandstorms that with in include water and dust

Prototypes were selected and with the help ofpropellers artificially created storm wasallowed to hit the glass panels at a greaterspeed

The glass panels withstands the storm up to75km/hr

TEST FOR THE CLADDING AGAINST STORM

As the building has to be built more than half a km, it had to challenge many factors that haven't faced by any other building

Has to be completed with in the short period limit

So the time was money

For erecting such a structure in the sky steel and glass panels have to be raised

This was done by cranes

SPEED OF CONSTRUCTION

The cranes consist of two plates on the twosides

It could jump from one floor to the another

So that they were called the kangaroo cranes

So as to speed up the construction the RCCwalls was done in a simple and cleverengineering way.

Cranes

For simplicity and speed the engineers made no. of steel cages

These cages were inserted to the formworks that can be moved easily

After installation of cages concrete was filled in these formworks

Only took 12hrs for the setting of concrete

After setting the concrete the formworks would move to the nextlevel with in 2hrs

CASTING OF RCC WALLS

High performance concrete(HPC)

Low permeability

High durability

C80-C60 cube strength concrete was used

It includes fly ash, Portland cement

Two largest concrete pumping machines in the world were used for this purpose

For reducing cracks due to high temperature concreting was done only at night

So that air is cooler and humidity is higher with ice added to the mix

CONCRETE USED

The pump needs 630HP to pump about 25000 tons of concrete

It had took about 14 mints for reaching the concrete to the 150th

floor

They completed every new floor in 3 day

CONCRETE USED Cont.

Every year the storm attacks Dubai

As the building grows much higher to the sky the top will be badly affected by the wind

This causes a sway at the top floors of the building

So that they studied many other skyscrapers

The buildings must be in a definite shape

WIND

They made a study on the Sears tower at Chicago

The Sears tower had a layer of steel, and an another layer of steel which forms an exoskeleton to the building

9 such blocks were used in this Sears tower in definite shape

So that the building was made rock solid

SHAPE

Giving the Burj a exoskeleton was not a easy task

So they designed the Burj in a triangular shape

So that this was suitable to deflect the wind to different ways

SHAPE Cont.

The three wings allow for greater building height by buttressing one another by a central core hence it is called buttressed core structural system

This buttressed core is a six sided central piece

So that it is called a Hexagonal Hub

BUTTRESSED CORE

This hub is surrounded by the three wings

These three wings afford the torsional resistance and the twisting of the tower

This hub encloses the elevators

BUTTRESSED CORE Cont.

The earthquake was one of the most important factor that had to be challenged by the Burj Khalifa

Any unknown concept would collapse the whole structure

They took the Taipie101 tower for their study

EARTHQUAKE

A year twice China is affected with earthquakes

The Taipei 101 was raised up with 36 steel tubes

They were filled with concrete for their rigidity

TAIPEI 101

These columns were holding together with outrigger trusses

So that these elastic bands would recover the whole movement occurred to the building

TAIPEI 101 Cont.

Providing such bands was not so practical for Burj

According to Uniform Building Code(UBC) ,Dubai was classified under a zone 2a

Moderate seismic activity

The Burj would resist up to 6 in the Richter scale

Because of the massive reinforced concrete skeleton

EARTHQUAKE Cont.

The attack against the world trade centre at sept2001 shows the importance of evacuation in skyscrapers

How tall the skyscrapers grow makes the evacuation much harder

The Burj is different and have a perfect evacuation system

EVACUATION

The Burj is naturally fire resistant as the concrete backbone is already fire resistant

More than that the Burj consist of refuge rooms

These refuge rooms are made of RCC and fire proof sheets that resist the heat up to 2hrs

These refuge rooms has a special supply of air which pumps through fire resistant pipes

There are 9 refuge rooms, one in every 30 floors

EVACUATION Cont.

The Burj Khalifa is one of the unique tallest building that was built by man

For rising such a city in the sky several new techniques have been used

The buttressed core structural system has made a great change in the structural system of skyscrapers

A strong buttressed core will initiate the height of the skyscrapers

The construction of the Burj Khalifa proves that height doesn't matter any civil engineering construction.

CONCLUSION

THANK YOU