Structural Engineering and Design of Burj Al Khalifa

The Buttressed Core Structural System

At 828 meters tall, the Burj Khalifa in Dubai represents the pinnacle of modern structural engineering. Traditional tall building configurations were insufficient to support a tower of this height while resisting extreme wind forces. To overcome this, the engineers at Skidmore, Owings & Merrill (SOM) developed a revolutionary structural concept: the buttressed core system.

The system consists of a hexagonal core reinforced by three wings that act as buttresses. As the height increases, the wings step back in a spiral pattern, reducing the building’s cross-section and disrupting wind vortex shedding.

Wind Engineering and Aerodynamic Shaping

Wind is the dominant design factor for skyscrapers. Over 40 wind tunnel tests were conducted on the Burj Khalifa to optimize its shape. The stepping design and rounded corners ensure that wind vortices do not synchronize, thereby drastically reducing dynamic lateral forces (along-wind and cross-wind responses).

High-Performance Concrete Mix Design

The tower’s concrete structure required the development of specialized concrete mixes capable of withstanding massive compressive forces (up to 120 MPa) and being pumped vertically to heights exceeding 600 meters in a single stage. High-strength self-consolidating concrete (SCC) with silica fume and fly ash was utilized, and concrete pouring was done exclusively at night to control temperature and prevent premature setting in the hot desert environment.