The geotechnical report for the Burj Khalifa provided critical information for constructing the foundation of the world's tallest building on weak soil conditions. Extensive testing of 23 boreholes found loose sands and weak stones requiring a deep foundation of 192 bored piles up to 50 meters long and a 3.7 meter thick raft foundation to distribute the building's over 500,000 ton weight. The unique architectural design and Dubai's weak soils presented challenges, but the engineered foundation system ensured less than 3 inches of settlement for the over 800 meter tall landmark.

1. GEOTECHNICAL REPORT
FOR
HIGH RISE BUILDING
BURJ KHALIFA

2. CASE STUDY : BURJ KHALIFA
The Burj Khalifa in October 2012
Former
names
Burj Dubai
Record height
Tallest in the world since 2010[I]
Preceded by Taipei 101
General information
Type Mixed-use
Architectura
l style
Neo-futurism
Location 1 Sheikh Mohammed bin Rashid
Boulevard,Dubai, United Arab Emirates
Coordinates 25°11′49.7″N55°16′26.8″ECoordinates: 25°11′49.
7″N 55°16′26.8″E
Construction
started
6 January 2004
Completed 30 December 2009

3. Cost USD $ 1.5 billion[2]
Height
Architectural 828 m (2,717 ft)[3]
Tip 829.8 m (2,722 ft)[3]
Roof 828 m (2,717 ft)
Top floor 584.5 m (1,918 ft) (Level 154)[3]
Observatory 555.7 m (1,823 ft) (Level 148)[3]
Technical details
Floor count 154 usable floors[3][4]
plus 9 maintenance levels, 46
spire levels,[5] and 2 below-ground
parking levels
Floor area 309,473 m2(3,331,100 sq ft)[3]
Lifts/elevators 57 (55 single deck and 2 double
deck), made by Otis Elevator
Company
Architect Adrian Smith at SOM
Developer Emaar Properties[3]
Structural
engineer
Bill Baker at SOM[6]
Main
contractor
Samsung C&T
Corporation, Besix andArabtec
Supervision Consultant Engineer &
Architect of Record Hyder
Consulting
Construction Project
Manager Turner Construction
Grocon[7]
Planning Bauer AGand Middle East
Foundations[7]
Lift contractor Otis[7]
VT consultant Lerch Bates[7]

4. INTRODUCTION
• The Burj Dubai Project is a multi-use
development tower with a total floor area of
460,000 square meters that includes residential,
hotel, commercial, office, entertainment,
shopping, leisure, and parking facilities. The Burj
Dubai project is designed to be the centerpiece of
the large scale Burj Dubai Development that rises
into the sky to an unprecedented height that
exceeds 700 meters and that consists of more
than 160 floors. The Client of Burj Dubai Tower,
Emaar Properties, is a major developer of lifestyle
real estate in the Middle East.

5. Turner International has been designated by the owner as the Construction
Manager, and Samsung Joint Venture (consisting of Samsung, Korea base contractor;
Besix, Belgium base contractor; and Arabtec, Dubai base contractor) as the General
Contractor. The design of Burj Dubai Tower is derived from geometries of the desert
flower, which is indigenous to the region,and the patterning systems . The modular
Y-shaped building, with a setback at every seventh floor, was part of the original
design concept that allowed Skidmore, Owings and Merrill to win the invited design
competition. The tower superstructure of Burj Dubai is designed as an all reinforced
concrete building with high performance concrete from the foundation level to level
156, and is topped with a structural steel braced frame from level 156 to the
pinnacle. 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.

7. FOUNDATION
• The foundation system for the Burj Dubai is comprised
of 192 bored piles . 1.5-m (approximately 5-ft) in
diameter and approximately 50-m deep (164-ft). A 3.7-
m (12-ft) thick raft foundation sits on top of the piles
under the full footprint of the structure.
• The Tower is founded on a 3700mm thick high
performance reinforced concrete pile supported raft
foundation . The reinforced concrete raft foundation
utilizes high performance Self Compacting Concrete
(SCC) and is placed over a minimum 100mm blinding
slab over waterproofing membrane, over at least
50mm blinding slab. The raft foundation bottom and
all sides are protected with waterproofing membrane

8. FOUNDATION
• Raft Foundation System (Raft foundation is a thick
concrete slab reinforced with steel which covers the
entire contact area of the structure like a thick floor.
Sometimes area covered by raft may be greater than
the contact area depending on the bearing capacity of
the soil underneath. The reinforcing bars runs normal
to each other in both top and bottom layers of steel
reinforcement. ). The piles are 1500mm diameter,
high performance reinforced concrete bored piles,
extending approximately 45 meters below the base of
the raft. pile capacities of 3000Tonnes.

10. STRUCTURE SYSTEM

11. SITE PLAN
• landscape design process Site planning generally
begins by assessing a potential site for
development through site analysis. Information
about slope, soils, hydrology, vegetation, parcel
ownership, orientation, etc. are assessed and
mapped. By determining areas that are poor for
development (such as floodplain or steep slopes)
and better for development, the planner or
architect can assess optimal location and design a
structure that works within this space

12. Now site plan of burj khalifa
• The Burj Dubai site area is approximately
105,600m2 and encompassing the tower, the
office annex, the pool annex, and the parking
areas, divided into three zones (Zone A, Zone
B, and Zone C). The site logistic works and
planning works are constantly evolving to
reflect current construction activities, lay-
down areas, site traffic circulation, etc.

14. IMPORTANCE OF GEOTECNICAL REPORT:
• The Geotechnical report provides critical and vital information for
the owner, architect, design engineer, and the contractor to use and
evaluate. A foundation failure of a major structure is measured in
millions of dollars and ruined careers. The drilling was carried out
using cable percussion techniques with follow-on rotary drilling
methods to depths between 30m and 140m below ground level. The
quality of core recovered in some of the earlier boreholes was
somewhat poorer than that recovered in later boreholes, and
therefore the defects noted in the earlier rock cores may not have
been representative of the actual defects present in the rock mass.
Phase 4 of the investigation was targeted to assess the difference in
core quality and this indicated that the differences were probably
related to the drilling fluid used and the overall quality of drilling
Standard Penetration Tests (SPTs) were carried out at various depths
in the boreholes and were generally carried out in the overburden
soils, in weak rock or soil bands encountered in the rock strata.

15. SOIL INVESTIGATION
• Before the building could be constructed, two years of
ground work had to be laid, including 6 months of
geotechnical investigation and testing, and a year and a
half of excavation and foundation construction. There
were many challenges faced by the geotechnical team
in the construction of the tower. These included the
unique architectural design of the building footprint
itself, the generally weak soil of the construction site
and the overall size of the structure, creating massive
loads on the foundation. As with most large buildings,
the Burj Khalifa uses a deep foundation design,
consisting of both a 3.7 meter thick raft foundation and
192 bored piles.

16. . The purpose of this design is to allow the weight of the building to be spread over a
larger volume of soil, decreasing the load in any given portion. Bored piles are piles
cast into drilled holes in the ground on site. This allowed the engineers of the project
to both create variable length piles depending on the loads the pile is expected to
bear, and to disturb the already weak soil much less than a traditional driving of piles
would. Where these piles would go and all their various properties were determined
after very extensive soil testing. 23 boreholes were drilled around the construction
site and extensive testing was performed in the area in and around where the
foundation would be placed, including inside the boreholes themselves. This found
that the soil was dominated by loose sands near the surface, and weak sand stones
and siltstones underneath. Because of the weak soil conditions, many large and very
deep piles were needed to properly stabilize the structure.

17. . The precise dimensions of the piles vary with the locations
around the site, but generally are 1.5 meters in diameter,
and 50 meters long for the building, and 30 meters long for the
surrounding plaza and podium. The final problem faced in the
foundation design was simply the large weight and size of the building.
This created large loads that had to be distributed between the slab and
the piles. With an empty weight of over 500,000 metric tons pushing
down and a building height of over 800 meters acting as a lever arm for
the high speed winds, the loads on the foundation are astronomical,
reaching a maximum of 37 Mega Newton's per pile on one side. This is
equivalent to over 5 and a half fully loaded Airbus A380’s stacked on top
of each other. But despite this massive weight, the incredible
engineering put into pile and slab design has kept the building from
settling even three inches.