Dubai’s most challenging skyscraper
In just over two decades, Dubai has transformed from a desert backwater port to a thriving metropolis with a futuristic looking architecture landscape, of which the most prominent: Burj Khalifa at a height of 829.8 metres making it the tallest building in Dubai, the Middle East – and the world.
When it opened in 2010, the Burj Khalifa knocked Taipei 101 from its throne, and took Dubai to new heights with the world’s highest observation deck and the world’s longest elevator journey.
This multi-use structure, which took six years to build, towers over Dubai’s constantly developing Downtown and Business Bay areas.
It’s also starred in numerous movies, including Mission Impossible: Ghost Protocol.
The decision to construct the building is based on the government’s decision to diversify from an oil-based economy, and for Dubai to gain international recognition.
The building was originally named Burj Dubai but was renamed in honour of the ruler of Abu Dhabi and president of the United Arab Emirates, Khalifa bin Zayed Al Nahyan.
The design for the 162-story tower combines local cultural influences with cutting-edge technology to achieve high performance in an extreme desert climate.
The centerpiece of a large mixed-use development, the Burj Khalifa contains offices, retail space, residential units, and a Giorgio Armani hotel. A Y-shaped floor plan maximizes views of the Arabian Gulf. At ground level, the Skyscraper is surrounded by green space, water features, and pedestrian-friendly boulevards.
The tower’s overall design was inspired by the geometries of a regional desert flower and the patterning systems embodied in Islamic architecture. Built of reinforced concrete and clad in glass, the tower is composed of sculpted volumes arranged around a central buttressed core. As the tower rises from a flat base, setbacks occur in an upward spiraling pattern, reducing the building’s mass as it reaches skyward. At the pinnacle, the central core emerges and forms a spire.
Beyond its record-breaking height, the Burj Khalifa incorporates new structural and construction efficiencies to reduce material usage and waste. These include a “sky-sourced” ventilation system, in which cool, less humid air is drawn in through the top of the building. The tower also has one of the largest condensate recovery systems in the world.
Building such a tall structure came with its own set of engineering challenges…
One of the first challenges of the Burj Khalifa was that the building had to withstand extreme heat, reaching more than 50 degree Celsius in summers. Accounting for that, an exterior cladding made of reflective glazing with aluminium and textured stainless steel panels were made. 300 cladding specialists were roped into individually hand-cut approximately 26,000 glass panels.
The hot climate posed a condensation challenge and around 15 million gallons of water gave off from the structure. To make up for it, a separate piping system was created to hold a tank in the basement to store the water.
Wind loads – To understand the behaviour of the wind and the amount of stress it could place on the building, the design team conducted over 40 wind tunnel tests. The top structure of the Burj Khalifa was made to resemble the letter ‘Y’ and each of the three wings of the structure buttressed others through this central core.
The combined weight of the concrete used for building the Burj Khalifa is equivalent to 100,000 elephants. The engineers had to mix the concrete with ice and pour it in the structure at night to skip the hot climate. This cooler mixture was also less likely to crack.
The total weight of all the aluminium used on the Burj Khalifa surpasses that of five A380 aircraft. These panels were lifted using a series of cranes and installed by specialists.
Burj Khalifa was designed by Adrian Smith, of Skidmore, Owings & Merrill, whose firm designed the Willis Tower and One World Trade Center.
Hyder Consulting was chosen to be the supervising engineer with NORR Group Consultants International Limited chosen to supervise the architecture of the project. The design is derived from the Islamic architecture of the region, such as in the Great Mosque of Samarra.
The Y-shaped tripartite floor geometry is designed to optimize residential and hotel space. A buttressed central core and wings are used to support the height of the building.
Although this design was derived from Tower Palace III, the Burj Khalifa’s central core houses all vertical transportation with the exception of egress stairs within each of the wings.
The structure also features a cladding system which is designed to withstand Dubai’s hot summer temperatures. It contains a total of 57 elevators and 8 escalators.