From the initial concept through to the completion,
a combination of technological and structural design
methods was required to create the efficient
and robust Burj Khalifa
Structural System
In addition to its aesthetic and functional advantages, the spiralling Y-shaped plan was utilised to shape the structural core of Burj Khalifa.
This Y-shaped design helps to reduce the wind forces on the tower, as well as to keep the structure simple and foster constructability.
Burj Khalifa’s structural design and system can be described as a buttressed core. This structural system allows for a dramatic increase in height.
The structural system consists of a three-winged structure anchored to a strong hexagonal central core. Each wing is buttressed to the other to provide a highly stable system.
The central core provides the torsional resistance of the structure while the wings resist the wind shears.
Foundation
Burj Khalifa is supported by a perfectly designed foundation made of a large reinforced concrete mat, which is in turn supported by bored reinforced concrete piles.
The reinforced concrete mat is 3.7 meters thick and was constructed in four separate pours totalling 12,500 cubic meters of concrete.
The concrete mat is as thick as two human beings and is made of high density, low permeability concrete.
The reinforced concrete mat is supported by concrete piles. The piles are 1.5 metres in diameter and 43 metres in length.
Podium
The podium provides a base anchoring the tower to the ground. It is one of the key structural elements of the tower and allows access from three different sides to three different levels of the building.
Fully glazed entry pavilions constructed with a suspended cable-net structure provide separate points of entry for the various levels including corporate levels, the Armani Hotel, and the private personal residences.
Exterior Cladding
The exterior cladding is made up of double-layer glass set within aluminum frames. Each glass panel weighs 362 kilogrammes.
Close to 26,000 glass panels were used in the exterior cladding with each one individually hand-cut. Over 300 cladding specialists from China were brought in for the cladding work.
Each glass panel features an energy-saving silver-coating to limit solar heat gain and withstand Dubai's extreme summer heat.
Burj Khalifa accomplished a world record for the highest installation of an aluminium and glass façade at a height of 512 metres.
Spire
The telescopic spire is Burj Khalifa’s crowning glory and secures its place as the world's tallest structure. It is made up of more than 4,000 tonnes of structural steel.
The spire was constructed from inside the building and jacked to its full height of over 200 metres using a hydraulic pump. The spire is integral to Burj Khalifa’s overall structural design and houses communications equipment.
To prevent air collisions, the spire features high-intensity xenon white obstruction lights. These lights flash 40 times per minute.
Services
The mechanical, electrical, and plumbing services for Burj Khalifa were developed in coordination during the structural design phase.
The tower's water system supplies an average of 946,000 litres (250,000 gallons) of water daily. That is more than 600 times the amount that an average family uses per day.
The tower’s condensate collection system provides about 15 million gallons of supplement water per year, equal to around 20 Olympic-sized swimming pools.
The tower's peak electrical demand is 36mW, equal to around 360,000 100-Watt bulbs operating simultaneously.
Service Floors
Seven double-storey height mechanical floors house equipment that is vital to Burj Khalifa’s operation and the comfort of its occupants. Equipment includes electrical sub-stations, water tanks and pumps, and air-handling units.
Track-mounted units and manned cradles keep the tower’s exterior clean and well maintained. It normally takes three to four months to clean the tower’s entire exterior.
Burj Khalifa features 57 lifts and 8 escalators and has the world's tallest service elevator with a capacity of 5,500 kg.
Fire and Safety
Fire safety and speed of evacuation are of paramount importance and Burj Khalifa has an extensive fire safety system and the world’s fastest lifts.
To give extra safety, Burj Khalifa’s stairways are reinforced with fireproof concrete.
Specially constructed air-conditioned and pressurised refuge areas are also located every 25 floors.