How the world’s tallest skyscraper was built - Alex Gendler

TED-Ed

Historical Context of Skyscraper Development

End of 20th century: skyscraper height race stalled
- New buildings only slightly taller than predecessors
- Architects running out of design innovations
2004: Dubai construction began on revolutionary design
2009: 828-meter Burj Khalifa completed
- Surpassed previous record-holder by over 60%

Heavy building materials made tall structures difficult to support own weight
Taller structures required wider, thicker masonry bases
- Substantially more expensive construction
Early 20th century: industrial steel arrival enabled height increases
- Steel frames shed building weight
- Required intensive labor under poor conditions
- 3D grids consumed huge interior space
- Larger, less dense surfaces vulnerable to strong winds
- Various countermeasures designed for swaying/structural damage

Bangladeshi-American engineer, "father of modern skyscrapers"
Core philosophy: tall structures should bear weight at widest, most stable points (exterior)
Proposed swapping internal steel beam grids for steel-concrete exoskeleton
- More wind-resilient
- Used far less heavy materials
Developed tubular designs concept
- Exterior steel frames braced with concrete
- Connected to horizontal floor beams
- Superior wind force absorption/transfer to foundation
- Exterior walls bear bulk of load
- Internal supporting columns removed for maximized space
Post-1960s: tubular design became industry standard
- Enabled taller, sturdier skyscrapers
- Many record holders used this approach

2004: Skidmore, Owings & Merrill (Khan's former employers) completed Tower Palace III, South Korea
Advanced Khan's exoskeleton design further
- Central column supported by three protruding wings
- Each wing's weight carries other two
- Heavy concrete core acts as support beam
- Houses elevators and mechanical infrastructure
Buttressed core design: entire structure functions as single load-bearing unit
- Supported Tower Palace III's 73 stories
SOM confident design could support much taller buildings

Second building using buttressed core design
163 floors spanning unprecedented height
Strategic placement of strongest load-bearing areas where wind most powerful
Y-shaped layout calibrated to minimize local wind forces
Setback pattern: wings recede slightly every several floors
- Forms clockwise spiral pattern
- Disperses air currents
- Transforms 240 km/h winds into harmless gusts

Completed in 5-year period despite height/complexity
Workforce: mostly South Asian migrants
Labor conditions:
- Shifts regularly over 12 hours long
- Daily wage approximately $10
- Workers attempting to quit/return home had paychecks and passports withheld
- Abusive conditions led to multiple protests
- At least one suicide and one fatal accident reported on site
Post-completion: UAE faced harsh scrutiny for failing to enforce worker protection laws

Try for free