Wind Engineering and The Burj Khalifa Building

The Burj Khalifa building in Dubai has tested and re-defined the way architects design tall buildings with regard to Wind engineering. In this essay I will be looking at how the design and testing of wind engineering techniques changed the design and construction of the Burj Khalifa. How have the latest advancements in design and wind-testing techniques been used to build the world’s current tallest building? Lets take a look.

Given that this building is 828m tall and consists of 162 floors, the Burj Khalifa designed by architect Adrian Smith of Skidmore, Owen and Merrill, (Al-Kodmany, 2011) had to ensure the tallest building in the world had structural stability. The higher the building the greater the effect of wind stress, a common problem being skyscrapers can sway and cause problems structurally and affect the people using it. The challenge with the Burj Khalifa was to design the shape to deflect the wind load around the structure and prevent the formation of whirlpools of high-speed air currents that would move the building from side-to-side causing structural damage. Many skyscrapers are designed with large surface areas characterised by glass windows for walls supported by steel frames with a tubular construction. These hollow cylinder-type structures are designed to resist wind and other lateral loads. However, the taller the building of this type is constructed the wind stress causes many problems which include extensive damage to the building. These issues were a case in New York’s former Gulf & Western building. (Flebowitz, 2010) Due to the effect of wind-stress, the 44-story building eventually gave way to cracked ceilings, stairwells and walls. Loud creaking noises were evident on windier days. Additionally, the office staff particularly on the higher floors experienced nausea when the wind was high. If these issues were not resolved the wind stress could have caused major structural damage or even collapse. So, to steady the structure a further investment of $10 million was spent to add steel braces. (Flebowitz, 2010)

Consequently, a conventional skyscraper design was not going to work for the Burj Khalifa. The architects designed the structure using the Tube Structural System that is now commonly used since the 1960s in buildings of 40 stories or more using Khans structural engineering principles. (Zweig, 2014) In particular, this building uses the bundled tube design which the architect Adrian Smith also used on the World One Trade Centre (Davidson, 2019) Smith’s design of the Burj Khalifa included a unique buttressed core in the shape of a ‘Y’. The purpose of this Y shape is to build a stronger core which will reduce wind stress. In between floors 88 and 92 is a tuned mass damper, that looks like a giant pendulum. This damper helps to act as a shock absorber. As the wind load pushes the structure in one direction the damper swings in the opposite direction which works to reduce the sway considerably. Prior to construction the design was given extensive wind load testing. After wind tunnel testing on a 1:500 scale model of the proposed building by Rowan Williams Davis & Irwin Inc. (RWDI), the design was dramatically altered to include a rotation of 120 degrees to reduce the wind stress. These design changes have made this not only one of the sturdiest buildings but has provided architects with important advances in the understanding of wind loads. In conclusion, I think you will agree that the unique architectural design and the wind-tests which influenced the final design changes made to the Burj Khalifa prior to construction show how important wind engineering is to structural engineers.