The Burj Khalifa project is located in downtown Dubai and includes residential, commercial, and entertainment spaces. At 828 meters tall with 162 floors, Burj Khalifa is the tallest man-made structure ever built and took over 6 years and $1.5 billion to construct. Its Y-shaped design was optimized through extensive wind tunnel testing to withstand high wind loads. An innovative reinforced concrete and steel framework supports the tower above a complex piled foundation system necessary to support its unprecedented height.
3. The burj khalifa project is located near
down -town dubai, UAE.
This is a multi-use tower that includes
residential, hotel, commercial offices,
entertainment, shopping, and parking
facilities.
It is the world’s tallest structure ever
built.
4. Its construction began on 21 September
2004, the exterior of the building was
finished on 1 October 2009.
It was under construction for six years.
It was inaugurated on 4th January 2010.
The total cost for the project was about
US $1.5 billion.
6. Architect/Structural/Design: Skidmore, Owings
and Merrill (SOM), Chicago.
Chief Architect & Engineer: Adrian Smith & Bill
Baker
Field supervision: Hyder Consulting Ltd.
General contractor: Samsung/BeSix/Arabtec
Foundation contractor: NASA Multiplex
Project Management: Turner Construction
Company
Developer: Emaar Properties, Dubai
7. The design of Burj Khalifa is derived from the
geometries of desert flower Hymenocallis.
The desert flower is indigenous to both the
region and patterning system embodied in
Islamic architecture.
8.
9. The tower is organized around a central
hexagonal core with three wings.
Each wing consists of four bays where, at
each 7th floor, one outer bay peels away as
the structure spiral into the sky.
The floor plan is characterized with a Y shape
which maximizes the views of the Persian
Gulf and provide tenants with plenty of
natural lights.
10. The structure is designed using:
1. Reinforced concrete (High performance
concrete) from the foundation to level 156.
2. Structural steel braced frame from level 156
to the pinnacle.
11.
12. Building a skyscraper poses challenges that
test the mind of any engineer. Burj Khalifa
stands a whopping 828m in the air making
it the tallest building in the world.
However, this was not accomplished without
overcoming several major engineering design
obstacles.
Here are some of the challenges and
innovations that the designers of Burj Khalifa
overcame and engineered:
13.
14. Select and optimize the tower structural
system for strength, stiffness, cost
effectiveness, redundancy, and speed of
construction.
Utilize the latest technologies and
construction methods.
Manage and locate the gravity load resisting
system so as to maximize its use in resisting
the lateral loads.
15. Incorporate the latest innovations in analysis,
design, materials, and construction methods.
Limit the building Movement (drift,
acceleration, tensional velocity, etc.) to
within the international accepted design
criteria and standards.
Control the dynamic response of the tower
under wind loading.
16. The tower’s lateral load resisting system
consists of high performance reinforced
concrete ductile core walls.
Walls are linked to the exterior reinforced
concrete columns through a series of
reinforced concrete shear wall panels.
The core walls vary in thickness from
1300mm to 500mm.
17. The core walls are typically linked through a
series of 800mm to 1100mm deep reinforced
concrete or composite link beams at every
level.
The lateral load resisting system of the spire
consists of a diagonal structural steel bracing
system from level 156 to the top of the spire.
The pinnacle consists of structural steel pipe
section varying from 2100mm diameter x
60mm thick at the base to 1200mm diameter
x 30mm thick at the top (828m).
19. Gravity load management is also critical as it
has direct impact on the overall efficiency and
performance of the tower.
The gravity load flow line should be smooth.
The total material needed to support the
gravity load and that required to resist the
combined effect of gravity and lateral loads is
shown in figures.
20.
21. The composite link beams were used as
means of transferring the gravity loads into
the center corridor Spine web walls
(650mm),to the hammer head walls and nose
columns for maximum resistance to lateral
loads.
Along these load flow lines the strain gages
are installed to track the gravity load flow.
The reinforced concrete center core wall at
level 156 provides the base support for the
spire and pinnacle structure.
22.
23.
24. As with any tall building, wind plays a major factor in
the construction and design process.
In order to begin building, the design team of Burj
Khalifa conducted over 40 wind tunnel tests at Guelph,
Ontario, Canada.
The 3D analysis and dynamic analysis indicated that the
tower sways 1.5m at its highest point.
Engineers spent months in wind tunnels with scale
models perfecting this “Y” shaped design. Wind could
strike the tower from any one direction and the
opposing leg of the “Y” would remain unstressed.
25.
26.
27. The wind engineering management of the tower
was achieved by:
Varying the building shape along the height while
continuing, without interruption, the building
gravity and lateral load resisting system.
Reducing the floor plan along the height, thus
effectively tapering the building profile.
As the wind encounters a different shape at each
new tier the wind vortices never gets organized,
thus reduced the wind forces.
28.
29. The foundations for the structure was one of
many challenges faced during the design
process.
The site was already mostly flat, but the
ground around the surface was not near
strong enough mostly comprised of loose to
medium sands on the surface level and even
week sandstone and siltstone underneath
that.
It was apparent from the beginning that
there was going to be some deeply set pillars
supporting the foundation.
30.
31. The pillars that were to be used were tested
in the laboratory and found to have a
maximum axial load capacity of 64MN.
Based on this number and the layout of the
projected building, a layout of 192 bores
piles were laid out running about 50m deep
into firmer grounds underneath.
The piles were 1.5m in diameter and
staggered about 4m from one another spread
through the foundation.
32.
33. An assessment of the foundations for the structure was
carried out and it was clear that piled raft foundations
would be appropriate for both the Tower and Podium
construction.
Tower piles were 1.5m diameter and 47.45m long.
The podium piles were 0.9m diameter and 30m long.
The thickness of the raft was 3.7m.
34.
35.
36. The task of laying concrete from ground
level to heights soaring above 1600 feet had
simply never been done before.
To do this, engineers simulated the effects of
pumping concrete to grand heights by testing
concrete through horizontal pipes on the
construction site.
Engineers successfully used 80 MPa of
pressure to pump concrete to a height of
1972 feet.
37.
38.
39. During the construction of the Burj Khalifa
people from all over the world came to work
on different aspects of the building.
During the height of construction over
12,000 workers were on site every day, and
after all was said and done over 60 contractor
companies had made their mark on this
extraordinary project.
Managing all these people and all these
operations was no small task that was only
complicated by the extreme conditions of the
building site.
40.
41. Impressive safety measures were implemented
throughout the building of the Burj Khalifa.
Workers initially were put through an extensive
training course.
The higher you climbed the more thorough was
the safety, which also depended on the type of
work that was to be done.
Strict, “almost military like” rules (Mohammad
Moiz Al Deen, health and safety manager at Burj
Khalifa) including a strict no smoking policy were
enforced throughout the project, with over 100
people being fired for various incidents.
42.
43. The stack effect is a common problem in
most high rise buildings and is also prevalent
but less pronounced and dangerous in
everyday buildings and houses.
The stack effect is the movement of air into
and out of buildings. Commonly, the warmer
air is lighter and less dense than cold air.
Therefore the warm air will rise to the top of
the building while the cold air will try to fill
the cracks in the bottom of the building.
44. This could be disastrous to a building as tall as
Burj Khalifa. Cracks in the foundation could
cause complete structural failure.
To mitigate this effect, the designers of the
building used several air duct systems to move
the warm air out of the building.
The stack effect cannot be completely
eliminated however it can be mitigated and
used as a ventilation system for the upper part
of the building.
45.
46. The development of the Survey and SHM
programs at Burj Khalifa included;
Testing all concrete grades to confirm the
concrete mechanical properties and
characteristic (strength, modulus of elasticity,
shrinkage and creep characteristics,
durability, heat of hydration, etc.)
Survey monitoring programs to measure the
foundation settlement, column shortening,
and tower lateral movement from the early
construction stage until the completion of the
structure.
47. Strain monitoring program to measure the actual
strains in the columns, walls, and near the
outrigger levels to confirm the load transfer into
the exterior mega columns.
Installation of the temporary real-time health
monitoring program to measure the building
lateral displacement and acceleration during
construction, and to identify the building
dynamic characteristics (frequencies, damping,
etc) during construction.
This system included bi-directional
accelerometers, GPS system, and weather station
(wind speed, wind direction, humidity, and
temperature).
48. Typical Strain Gage Monitoring System Concept and Layout for the tower superstructure
and foundation systems.
49. Detailed summary of the temporary real time monitoring program configuration and
building movement during construction (due to Sept. 10 2008 earthquake in Iran)
50. Installation of a permanent real-time structural
health monitoring (SHM) program to measure
the building acceleration, movement, dynamic
characteristics (frequencies, mode shapes),
acceleration time history record and tilt of the
foundation at the base of the tower, wind
velocity profile along the entire height, weather
station, and fatigue behaviour of the
spire/pinnacle.
51. Detailed summary of the permanent real-time Structural Health Monitoring (SHM)
program concept developed by the author for Burj Khalifa.
52. Concrete construction showed to be at its
infancy where nobody has dreamt of creating
such a tall building using concrete.
Burj khalifa project has demonstrated that as
the technologies advance, the super tall
building won’t be a dream anymore.
Burj khalifa is a step forward in meeting the
technological challenges of future
construction.
Burj khalifa simply proved that ‘Nothing is
Impossible ’