structural design system and irregularity that may occur in seismic design.

1. Special topic in structural Engineering
Capital Gate Abu
Dhabi
Bara AlRefai
United Arab Emirates University

2. Capital Gate
❖ 160 m tall
❖ 35 stories
❖ Inclined 18 degree to west.
❖ Capital gate title four times
more than the Tower of Pisa.
❖ It got Guinness certificate for
furthest leaning man mad
tower.

3. Capital Gate
❖

4. Capital Gate
❖ Cost $233 million.
❖ 600 people labor force
participate in construction.
❖ Two year of constriction.
❖ Completed in 2011.
❖ Total Area :53,100 square
meter.
❖ Mainly used for hotel and
offices.

5. Structural system
❖ Concrete core surrounded by
two steel truss (diagrid
system).
❖ External and internal diagrid
system (lateral load resisting
system).
❖ Steel beam support concrete
floor & run between two diagrid
system.

6. Structural system
❖ Outriggers are horizontal trusses
connect building core distant
structural element.
❖ Used to increase strength and
overturning stiffness.
❖ The dense outriggers system
started to be used from17th
mechanical floor.
❖ Mainly used to resist wind load.

7. Foundation
❖ Rectangular raft footing.
❖ 2 m depth and 7000 cubic
meter reinforced concrete.
❖ 490 piles.
❖ Each has 1 m diameter.
❖ Half under compression with
depth of 20 m.
❖ Other half under testation with
depth of 30 m.

8. Loads calculations
❖ Source:
❖ https://sites.google.com/site/gr
oup5capitalgate/structure/i-
analysis-and-description

9. Irregularity that Should be taken in
consideration
❖ The flowing Vertical
Irregularities that may exist in
Capital Gate Abu Dhabi :
1. Stiffness irregularity.
2. Mass irregularity.
❖ The flowing plan Irregularities
that may exist in Capital Gate
Abu Dhabi :
1. Torsional irregularity.
2. Diaphragm Discontinuity.
3. Out-of-plane Offsets of vertical
Element.

10. Thank You

11. References
❖ www.rmjm.com/the-architects-perspective-the-capital-gate
❖ www.e-architect.co.uk/dubai/capital-gate-abu-dhabi
❖ www.economist.com/blogs/dailychart/2011/10/leaning-
buildings
❖ www.slideshare.net/nayanrao1/seminar-on-capital-gate-
building
❖ https://sites.google.com/site/group5capitalgate/structure/iii-
drawings-and-diagrams
❖ https://store.ctbuh.org/PDF_Previews/Books/2012_CTBUHO
utriggerGuide_Preview.pdf