Burj Khalifa برج خليفة

8/10/2019 Burj Khalifa برج خليفة

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BUILDING STRUCTURE

ASSIGNMENT 01

World's tallest building. A living wonder. Stunning work of art. Incomparable feat of engineering.

What influences me to choosethis building?

Being known as the tallest

building in the world, I wonder

how the structure can support

all loads and pressure up to the

sky while maintaining a simple

elegant design.



Official Name : Burj Khalifa Bin Zayed

Formerly Known : Burj Dubai

Built : 2004-2010

Cost : $4,100,000,000

Designed By : Skidmore, Owings & Merrill (SOM)Developer : Emaar

Type : Skyscraper Mixed-Use (Mall, Residential And Retail Facilities)

No. of Stories : 206

Maximum Height : 2,717 Feet / 828 Meters

Location : Burj Dubai Boulevard, Dubai, United Arab Emirates





World Records

At over 828 metres (2,716.5 feet) and more than 160 stories, Burj Khalifa holds the following records:

• Tallest building in the world

• Tallest free-standing structure in the world

• Highest number of stories in the world

• Highest occupied floor in the world

• Highest outdoor observation deck in the world

• Elevator with the longest travel distance in the world

• Tallest service elevator in the world



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Q1: What is the function of this building structure?

ANSWER:The 280,000-square-meter skyscraper is a mixed-use project contains office, residential,

and retail space, along with a Giorgio Armani hotel.

Burj Khalifa is good for communication, hotel, observation, office, residential, retail,

entertainment, shopping, leisure and parking facilities.



Armani Hotel & Residences Dubai

160 guestrooms and suites , 144 private residences

At the Top, Burj Khalifa

Observation deck on level 124

At.mosphere, Burj Khalifa

Fine dining restaurant on level 122

The Residence

900 Burj Khalifa residences

The Corporate Suites

37 office floors



The inspiration for this building comes from the

regional desert ‘Hymenocallis’ flower (as shown in

figure).

Just like the petals stretch outwards from the

stem, the wings of Burj Khalifa pull out from the

central core, giving an abstract “Y” form to the

building.

The design also incorporated the patterning

principles found in Islamic architecture.The form of Burj Khalifa reflects Islamic

Architecture through the use of onion domes

when the building is viewed from the sky, or the

base.“Hymenocallis”, also known as Spider Lily

(Organic Inspiration)





Q4: What type of materials are used?

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

• Concrete (About 250,000 m2 concrete was also used)

• Steel (Over 30,000 tons of steel were used)

The reinforced concrete acts as the backbone of

the whole structure.

The concrete and steel skeleton is being

covered with a skin of glass, aluminum

and steel.

Thus, the overall materials of the structure are

glass, steel, aluminium, concrete andreinforced.

Q2: How would you classify this structure?

ANSWER:

Burj Khalifa is a mass structure as the concrete filled in the steel rebar to make it strong andsolidly built.



Q3: List down and explain elements of structure in this chosen building.

1. The design of the plan “buttressed” hexagonal

hub

• The hub is where the elevators are located

and can be regarded as an axis preventing

twisting of the structure.

• Each wing, with its own high performance

concrete corridor walls and perimeter

columns, buttresses the others via a six-sided

central core, or hexagonal hub.

• According to the structural head of SOM

who were the structural engineers of Burj

Khalifa, a tapering Y shaped plan would be

the most efficient design for a skyscraper

and would occupy a lesser footprint

compared to say a rectangular block for thesame height.



2. The Structural System

• There are corridor walls extending from the

hub and terminating in thickened hammerhead

walls, which behave similarly to the webs and

flanges of a beam to resist the wind shears andmoments. There also have some perimeter

columns and flat plate floor construction.

• All of the vertical concrete is utilized to support

both gravity and lateral loads.

• The tower is extremely stiff laterally and

torsionally.

3. Building Stepping

• As the building spirals in height, the wings set back to provide many different floor

plates.

• The setbacks are organized with the tower’s grid, such that the building stepping isaccomplished by aligning columns above with walls below to provide a smooth load

path.

• This stepping and shaping of the tower has the effect of “confusing the wind”: wind

vortices never get organized over the height of the building because at each new tier the

wind encounters a different building shape.



4. Vertical design of the structure—tapered profile

• The overall shape of the structure is slender at the top and wider at the base.

• Such decision is suitable for resisting the shear and bending moment distributed on

the structure: the shear and bending moment accumulate from the top to the

bottom. And at the same time, such shape is wise when considering the whole

structure as a cantilever beam fixed in the ground, since it has larger size of the

internal moment arm and smaller forces in vertical members when providing the

same internal resisting moment.



5. Foundation and Soil

• The soil stratum of Dubai is very week so

they had to excavate up to 50m deep to geta hard rock structure.

• But the rock that they found was fragile

and saturated with ground water

• 194 piles were constructed for avoiding the

sinking of this structure.

• The Tower is founded on a 3700mm thickhigh performance reinforced concrete pile

supported raft foundation, which is in turn

supported by bored reinforced concrete

piles.

• The raft foundation bottom and all sides

are protected with waterproofingmembrane.



6. Podium

• The Podium provides a base anchoring the tower to the ground, allowing on grade

access from three different sides to three different levels of the building.

• Fully glazed entry pavilions constructed with a suspended cable-net structure provide

separate entries for the corporate suites at B1 and Concourse levels, the Burj Khalifa

residences at ground level and the Armani Hotel at Level 1.

* Podium: A platform that is used to raise something to a short distance above its surroundings.



ANSWER:

• The centre hexagonal reinforced concrete core walls provide the torsional resistance

of the structure similar to a closed tube or axle.

• The centre hexagonal walls are buttressed by the wing walls and hammer head walls

which behave as the webs and flanges of a beam to resist the wind shears andmoments.

• Outriggers at the mechanical floors allow the columns to participate in the lateral

load resistance of the structure; hence, all of the vertical concrete is utilized to

support both gravity and lateral loads.

• The top section of the Tower consists of a

structural steel spire utilizing a diagonally

braced lateral system. The structural steelspire was designed for gravity, wind, seismic

and fatigue. The exterior exposed steel is

protected with a flame applied aluminum

finish.

Q9: How well does your structure resist all forces including tension,

compression, torsion and shear forces?

* Torsion: the act of twisting or the state of being twisted



Dead Load Calculation

Concrete //430,000 CY -> 11,610,000 CF X 145 LB/CF = 1,683,450,000 LB

Steel Reinforcement // 39,000 TON x 2000 LB/TON = 78,000,000 LB

Glass // 1,100,000 SF x 0.0328 FT x 185 LB/CF = 6,674,800 LB

Embossed Stainless Steel // 167,000 SF x 2.52 LB/SF = 420,840 LB

Dead Load = 1,811,687,392 LB

* Each material was given in a particular unit, then converted to pounds for use in loadcalculation.

** Stainless Steel was assumed to be of gauge 16, the one found most often in buildings.

Live Load Calculation

Commercial Floor Area = 300,000 SF

Commercial Floor Load = 80 LB/SF x 300,000 SF = 24,000,000 LB

Residential Floor Area = 5,370,000 SF

Residential Floor Load = 40 LB/SF x 5,370,000 SF = 214,800,000 LB

Live Load = 238,800,000 LB

Foundation Load Calculation

Total Load = Dead Load + Live Load = 2,050,487,392 LB

Building Footprint = 80,000 SF

Foundation Load = Total Load / Building Footprint = 25,631 LB/SF

Horizontal Wind Load Calculation

Max Wind Speed = 68 MPH = 12 LB/SF

Building Face Area = 370,000 SF

Horizontal Load = Wind Speed*2 x Building Face Area = 8,880,000 LB

* Max wind speed was found from Dubai weather data, then doubled in the load calculation for

safety measures.

** Building face area was determined by dividing the amount of glass by the three outer faces

(as there was no recorded value).



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

• The tower’s lateral load resisting system

consists of high performance, reinforced

concrete ductile core walls linked to the

exterior reinforced concrete columns through

a series of reinforced concrete shear wall

panels at the mechanical levels.

• Due to the limitation on the link beamdepths, ductile composite link beams are

provided in certain areas of the core wall

system.

• These composite ductile link beams typically

consist of steel shear plates, or structural

steel built-up I-shaped beams, with shear

studs embedded in the concrete section.

Lateral Load Resistance System

Lateral load resistance is one of the dominant concerns for the design of Burj Dubai, which is

ambitiously to be the tallest building in the world. Tall buildings have to be capable of coping with

significant lateral forces, namely strong winds, and in the case of the Burj Dubai, seismic forces

too.



The tower massing is also driven by wind engineering requirements to reduce dynamic wind

excitation. As the tower spirals into the sky, the building’s width and shape diminish, thus reducing

wind dynamic effects, movement, and acceleration. Integrating wind engineering principals and

requirements into the architectural design of the tower results in a stable dynamic response,

taming the powerful wind forces.









Gravity Load Resistance System

In the lower level, the concrete system(shear wall, column) is the main way to support the gravity

load, The wall thicknesses and column sizes were fine-tuned to reduce the effects of creep and

shrinkage on the individual elements which compose the structure.







ANSWER:

Joints that are used in this structure are adhesives, fastenings and melting (brazing).

Q5 & Q6: What types of fasteners/joints do they use in building structure?

Q7: What design problems did you run into during the research of this

structure?

ANSWER:

The most important building materiel of Burj Khalifa is reinforced concrete. A special

concrete was needed because of the high pressures of the building's weight and the

hot local climate. Persian Gulf temperatures that can reach 50 °C (122 °F). Any major

cracks could have caused a large amount of damage to the building.



Q8: How much do you think your structure is worth? Why?

Q10: Any suggestion of the ways that can increase the stability of your

structure?

ANSWER:

Burj Khalifa is worthy because this iconic building is more than just the tallest

building in the world, it is a work of structural art; it will serve as an important

benchmark in the fields of architecture and structural engineering for decades to

come. This iconic building symbolizes the aesthetic unison of many cultures – from

Arabia and the rest of the world.

ANSWER:The stability of Burj Khalifa is sufficient as the structure has undergo a lot of wind

tunnel testing and refining of the structural system.



• Burj Khalifa has redefined what is possible in the design and engineering of supertall

buildings.• At the turn of the century, concrete construction was at its infancy and nobody then

could have dreamed of creating a building this tall using concrete.

• The Burj Dubai project demonstrates that tall building system development is always

directly related to the latest developments in material technologies, structural

engineering theories, wind engineering, seismic engineering, computer technologies, and

construction methods. As of today, the Burj Dubai is the tallest man made structure in

the world in all categories, and it has become a catalyst for further development inhighrise construction in the Middle East and throughout the world.

• The Burj Dubai project is another step forward in the world of architecture.

Documents

Burj Khalifa برج خليفة