Friday, 18 September 2015

BURJ KHALIFA DESIGN BRIEF

The present article provides ready reference structural information about the world’s tallest structure Burj Khalifa. The main objective of article is to provide bench mark quantities for structural information for tall building.


Project Type
:
Mixed Use Project ( Five Star Hotel, Office, Retail and Residential)

Total Floor area
:
439,935m2

Site Area
:
104,210m2

Height
:
828m ( Concrete 606m Plus Steel  222m)

Gross Floor area above Grade
:
312,400m2

Floor Plate Size at Grade Level
:
3,065m2

Floor Plate Size at Upper top
:
380 m2

Floor Plate Size at Basement
:
35,300m2

Structural Consultant
:
SOM

Wind Engineering Consultant
:
RWDI
Wind Tunnel Analysis
Rigid Model Force Balance Tests
Full Multi Degree of Freedom Aero-elastic Model

Floor Geometry in Plan
:
Y Shaped (to reduce the wind forces on the tower, as well as to keep the structure
Simple and foster constructability)

Structural System
:
“Buttressed” Six Sided Central Core, Each wing, with its own high performance concrete core and
perimeter columns, buttresses the others via a six-sided central core, or
hexagonal hub

Foundation
:
Pile Supported Raft

Number of piles under tower
:
194

Pile Diameter
:
1.5m

Length of pile
:
43.0m

Concrete Cube Strength for Pile
:
60MPa SCC ( Self Compacting Concrete)( Triple Blend 25% Fly Ash + 7% Micro silica + Portland Cement, Water Cement ratio 0.32)

Pile Load Test
:
6000 t

Working Design Capacity
:
3000 t

Raft Thickness
:
3.7m

Reinforcement Spacing
:
300 mm c/c­­­­

Concrete Cube Strength for Raft
:
C50 Self Consolidating Concrete


Super Structure



Number of Outrigger Levels
:
5

Concrete cube strength for Vertical Element (Reinforced Concrete Wall/column)
:
C80 ( at Base checked at 90 Days instead of 28 Days) – C60 (at Upper Level)


Composition of Concrete for Vertical Elements
:
Portland Cement + Fly Ash


Analysis Software and Model Size
:
ETABS (Version 8.4) , 73,500 Shells and 75,000 Nodes

Reinforced Concrete Design Code
:
ACI 318-02


Free Vibration Analysis Result
1st Mode, Lateral Side sway
2nd Mode, Lateral Side sway
5th Mode, Torsion Mode

:
:
:

11.3 sec
10.2 sec
4.3 sec

Top Steel Portion ( Spire)
:
Diagonally braced lateral system

Steel Design Code
:
AISC LRFD 1999

Seismic Zone
:
Zone 2A ( Z = 0.15) as per UBC97

Modulus of Elasticity of Concrete (Ec)for Core and Outrigger at Lower Portion at 90 Day
:
43,800MPa

Walls and Columns optimized
:
Virtual Work Method


Effect of Column Shortening
:
Perimeter columns were sized such that the self-weight gravity stress on the perimeter columns matched the stress on the interior corridor walls.


Weight of Empty Building
:
500,000MT

Quantity



Concrete
:
330,000 m3

Reinforcement Steel
:
39,000MT

Glass used for Façade
:
103,000 m2

Stainless Steel used for Cladding
:
15,500 m2

Structural Steel for Top Spire
:
Approximately 4000MT


                                    

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