Burj Khalifa

BURJ KHALIFA'S GRAND VISION

World's tallest building. A living wonder. Stunning work of art. Incomparable feat of engineering. Burj Khalifa is all that. In concept and execution, Burj Khalifa has no peer.

More than just the world's tallest building, Burj Khalifa is an unprecedented example of international cooperation, symbolic beacon of progress, and an emblem of the new, dynamic and prosperous Middle East.

It is also tangible proof of Dubai's growing role in a changing world. In fewer than 30 years, this city has transformed itself from a regional centre to a global one. This success was not based on oil reserves, but on reserves of human talent, ingenuity and initiative. Burj Khalifa embodies that vision.

Mr Mohamed Alabbar, Chairman, Emaar Properties, said: "Burj Khalifa goes beyond its imposing physical specifications. In Burj Khalifa, we see the triumph of Dubai's vision of attaining the seemingly impossible and setting new benchmarks. It is a source of inspiration for every one of us in Emaar. The project is a declaration of the emirate's capabilities and of the resolve of its leaders and people to work hand in hand on truly awe-inspiring projects.  

Emaar had but one inspiration, the unflagging enthusiasm set in motion by His Highness Sheikh Mohammed Bin Rashid Al Maktoum, Vice President and Prime Minister of the UAE and Ruler of Dubai, who inspires us to reach for the stars.

Bringing Burj Khalifa to life required a combination of visionary ideals and solid science. In the process, the project amassed an awe-inspiring number of facts, figures, and statistics.

World Records

At over 828 metres (2,716.5 feet) and more than 160 stories, Burj Khalifa holds the following records:

•  Tallest building in the world

•  Tallest free-standing structure in the world

•  Highest number of stories in the world

•  Highest occupied floor in the world

•  Highest outdoor observation deck in the world

•  Elevator with the longest travel distance in the world

•  Tallest service elevator in the world 

Tallest of the Supertall

Not only is Burj Khalifa the world’s tallest building, it has also broken two other impressive records: tallest structure, previously held by the KVLY-TV mast in Blanchard, North Dakota, and tallest free-standing structure, previously held by Toronto’s CN Tower. The Chicago-based Council on Tall Buildings and Urban Habitat (CTBUH) has established 3 criteria to determine what makes a tall building tall. Burj Khalifa wins by far in all three categories.  

Height to architectural top

Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the architectural top of the building. This includes spires, but does not include antennae, signage, flagpoles or other functional-technical equipment. This measurement is the most widely used and is used to define the Council on Tall Buildings and Urban Habitat rankings of the Tallest Buildings in the World.

             

Highest occupied floor

Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the highest continually occupied floor within the building. Maintenance areas are not included.

           

Height to tip

Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the highest point of the building, irrespective of material or function of the highest element. This includes antennae, flagpoles, signage and other functional-technical equipment.

WHAT'S INSIDE

At the Top, Burj Khalifa

Observation deck on level 124

At.mosphere, Burj Khalifa

Fine dining restaurant on level 122

The Residence

900 Burj Khalifa residences

The Corporate Suites

37 office floors

Armani Hotel Dubai

160 guestrooms and suites

Armani Residences Dubai

144 private residences

The Park

11 hectares park, 6 water features

3000 underground parking spaces

The Club

4-storey fitness and recreation annex

INSPIRED DESIGN

While it is superlative in every respect, it is the unique design of Burj Khalifa that truly sets it apart. The centrepiece of this new world capital attracted the world's most esteemed designers to an invited design competition.

Ultimately, the honour of designing the world's tallest tower was awarded to the global leader in creating ultra-tall structures, the Chicago office of Skidmore, Owings & Merrill LLP (SOM) with Adrian Smith FAIA, RIBA, consulting design Partner. The selected design was subject to an extensive peer review program to confirm the safety and effectiveness of the structural systems.

Architecture

Wind Testing

Floor Plan

Interiors

Artwork

Architecture

The architecture features a triple-lobed footprint, an abstraction of the Hymenocallis flower. The tower is composed of three elements arranged around a central core. The modular, Y-shaped structure, with setbacks along each of its three wings provides an inherently stable configuration for the structure and provides good floor plates for residential. Twenty-six helical levels decrease the cross section of the tower incrementally as it spirals skyward.

The central core emerges at the top and culminates in a sculpted spire. A Y-shaped floor plan maximizes views of the Arabian Gulf. Viewed from the base or the air, Burj Khalifa is evocative of the onion domes prevalent in Islamic architecture.

Wind Tunnel Testing

Over 40 wind tunnel tests were conducted on Burj Khalifa to examine the effects the wind would have on the tower and its occupants. These ranged from initial tests to verify the wind climate of Dubai, to large structural analysis models and facade pressure tests, to micro-climate analysis of the effects at terraces and around the tower base. Even the temporary conditions during the construction stage were tested with the tower cranes on the tower to ensure safety at all times.

Stack effect or chimney effect is a phenomenon that effects super-tall building design, and arises from the changes in pressure and temperature with height. Special studies were carried on Burj Khalifa to determine the magnitude of the changes that would have to be dealt with in the building design.

Floor Plan

Concourse level to level 8 and level 38 and 39 will feature the Armani Hotel Dubai. Levels 9 to 16 will exclusively house luxurious one and two bedroom Armani Residences.

Floors 45 through 108 are private ultra-luxury residences. The Corporate Suites occupy most of the remaining floors, except for level 122 which houses a restaurant and level 124, the tower's public observatory.

For the convenience of home owners, the tower has been divided in to sections with exclusive Sky Lobbies on Levels 43, 76 and 123 that feature state-of-the-art fitness facilities including a Jacuzzis on Level 43 and 76. The Sky Lobbies on 43 and 76 additionally house swimming pools and a recreational room each that can be utilized for gatherings and lifestyle events. Offering an unparalleled experience, both pools open to the outside offering residents the option of swimming from inside to the outside balcony.

Other facilities for residents include a Residents' Library, and Burj Khalifa Gourmet Market, a gourmet convenience store and meeting place for the residents. Valet parking will be provided for guests and visitors.

Interiors

The interior design of Burj Khalifa public areas was also done by the Chicago office of Skidmore, Owings & Merrill LLP and was led by award-winning designer Nada Andric. It features glass, stainless steel and polished dark stones, together with silver travertine flooring, Venetian stucco walls, handmade rugs and stone flooring. The interior were inspired by local culture while staying mindful of the building's status as a global icon and residence.

Artwork

Over 1,000 pieces of art from prominent Middle Eastern and international artists will adorn Burj Khalifa and the surrounding Emaar Boulevard. Many of the pieces were specially commissioned by Emaar to be a tribute to the spirit of global harmony. The pieces were selected as a means of linking cultures and communities, symbolic of Burj Khalifa being an international collaboration.

BUILDING A GLOBAL ICON

Excavation work began for Burj Khalifa in January 2004 and over the ensuing years to its completion, the building passed many important milestones on its goal to become the tallest man-made structure the world has ever seen. In just 1,325 days since excavation work started in January, 2004, Burj Khalifa became the tallest free-standing structure in the world. 

Burj Khalifa Construction Timeline

January 2004	Excavation started
February 2004	Piling started
March 2005	Superstructure started
June 2006	Level 50 reached
January 2007	Level 100 reached
March 2007	Level 110 reached
April 2007	Level 120 reached
May 2007	Level 130 reached
July 2007	Level 141 reached - world's tallest building
September 2007	Level 150 reached - world's tallest free-standing structure
April 2008	Level 160 reached - world's tallest man-made structure
January 2009	Completion of spire - Burj Khalifa tops out
September 2009	Exterior cladding completed
January 2010	Official launch ceremony

 Construction Highlights

Over 45,000 m3 (58,900 cu yd) of concrete, weighing more than 110,000 tonnes were used to construct the concrete and steel foundation, which features 192 piles buried more than 50 m (164 ft) deep. Burj Khalifa's construction will have used 330,000 m3 (431,600 cu yd) of concrete and 39,000 tonnes (43,000 ST; 38,000 LT) of steel rebar, and construction will have taken 22 million man-hours.

Exterior cladding of Burj Khalifa began in May 2007 and was completed in September 2009. The vast project involved more than 380 skilled engineers and on-site technicians. At the initial stage of installation, the team progressed at the rate of about 20 to 30 panels per day and eventually achieved as many as 175 panels per day.

The tower accomplished a world record for the highest installation of an aluminium and glass façade, at a height of 512 metres. The total weight of aluminium used on Burj Khalifa is equivalent to that of five A380 aircraft and the total length of stainless steel bull nose fins is 293 times the height of Eiffel Tower in Paris.

CONSTRUCTION TEAM

Burj Khalifa was truly an international collaboration between more than 30 on-site contracting companies from nations around the world.

At the peak of construction, over 12,000 workers and contractors were on site everyday, representing more than 100 nationalities.

STRUCTURAL ELEMENTS — ELEVATORS, SPIRE, AND MORE

It is an understatement to say that Burj Khalifa represents the state-of-the-art in building design. From initial concept through completion, a combination of several important technological innovations and innovation structural design methods have resulted in a superstructure that is both efficient and robust.

• Foundation
• Podium
• Structural System
• Exterior Cladding
• Spire
• Mechanical Floors
• Window Washing Bays
• Broadcast Floors
• Mechanical, Electrical & Plumbing
• Fire Safety
• Elevators & Lifts

Foundation

The superstructure is supported by a large reinforced concrete mat, which is in turn supported by bored reinforced concrete piles. The design was based on extensive geotechnical and seismic studies. The mat is 3.7 meters thick, and was constructed in four separate pours totaling 12,500 cubic meters of concrete. The 1.5 meter diameter x 43 meter long piles represent the largest and longest piles conventionally available in the region. A high density, low permeability concrete was used in the foundations, as well as a cathodic protection system under the mat, to minimize any detrimental effects form corrosive chemicals in local ground water.

Podium

The podium provides a base anchoring the tower to the ground, allowing on grade 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 entries for the Corporate Suites at B1 and Concourse Levels, the Burj Khalifa residences at Ground Level and theArmani Hotel at Level 1.

Exterior Cladding

The exterior cladding is comprised of reflective glazing with aluminum and textured stainless steel spandrel panels and stainless steel vertical tubular fins. Close to 26,000 glass panels, each individually hand-cut, were used in the exterior cladding of Burj Khalifa. Over 300 cladding specialists from China were brought in for the cladding work on the tower. The cladding system is designed to withstand Dubai's extreme summer heat, and to further ensure its integrity, a World War II airplane engine was used for dynamic wind and water testing. The curtain wall of Burj Khalifa is equivalent to 17 football (soccer) fields or 25 American football fields. 

Structural System

 In addition to its aesthetic and functional advantages, the spiraling “Y” shaped plan was utilized to shape the structural core of Burj Khalifa.  This design helps to reduce the wind forces on the tower, as well as to keep the structure simple and foster constructability. The structural system can be described as a “buttressed core”, and consists of high performance concrete wall construction. Each of the wings buttress the others via a six-sided central core, or hexagonal hub. This central core provides the torsional resistance of the structure, similar to a closed pipe or axle. Corridor walls extend from the central core to near the end of each wing, terminating in thickened hammer head walls. These corridor walls and hammerhead walls behave similar to the webs and flanges of a beam to resist the wind shears and moments. Perimeter columns and flat plate floor construction complete the system. At mechanical floors, outrigger walls are provided to link the perimeter columns to the interior wall system, allowing the perimeter columns to participate in the lateral load resistance of the structure; hence, all of the vertical concrete is utilized to support both gravity and lateral loads. The result is a tower that is extremely stiff laterally and torsionally. It is also a very efficient structure in that the gravity load resisting system has been utilized so as to maximize its use in resisting lateral loads.

As the building spirals in height, the wings set back to provide many different floor plates. The setbacks are organized with the tower’s grid, such that the building stepping is accomplished by aligning columns above with walls below to provide a smooth load path. As such, the tower does not contain any structural transfers. These setbacks also have the advantage of providing a different width to the tower for each differing floor plate. This stepping and shaping of the tower has the effect of “confusing the wind”: wind vortices never get organized over the height of the building because at each new tier the wind encounters a different building shape.

Spire

The crowning touch of Burj Khalifa is its telescopic spire comprised of more than 4,000 tons of structural steel. The spire was constructed from inside the building and jacked to its full height of over 200 metres (700 feet) using a hydraulic pump. In addition to securing Burj Khalifa's place as the world's tallest structure, the spire is integral to the overall design, creating a sense of completion for the landmark. The spire also houses communications equipment.

Mechanical Floors

Seven double-storey height mechanical floors house the equipment that bring Burj Khalifa to life. Distributed around every 30 storeys, the mechanical floors house the electrical sub-stations, water tanks and pumps, air-handling units etc, that are essential for the operation of the tower and the comfort of its occupants.

Window Washing Bays

Access for the tower's exterior for both window washing and façade maintenance is provided by 18 permanently installed track and fixed telescopic, cradle equipped, building maintenance units. The track mounted units are stored in garages, within the structure, and are not visible when not in use. The manned cradles are capable of accessing the entire facade from tower top down to level seven. The building maintenance units jib arms, when fully extended will have a maximum reach of 36 meters with an overall length of approximately 45 meters. When fully retracted, to parked position, the jib arm length will measure approximately 15 meters. Under normal conditions, with all building maintenance units in operation, it will take three to four months to clean the entire exterior facade.

Broadcast and Communications Floors

The top four floors have been reserved for communications and broadcasting. These floors occupy the levels just below the spire.

Mechanical, Electrical & Plumbing

To achieve the greatest efficiencies, the mechanical, electrical and plumbing services for Burj Khalifa were developed in coordination during the design phase with cooperation of the architect, structural engineer and other consultants.

• The tower's water system supplies an average of 946,000 litres (250,000 gallons) of water daily
• At peak cooling, Burj Khalifa will require about 10,000 tons of cooling, equal to the cooling capacity provided by about 10,000 tons of melting ice
• Dubai's hot, humid climate combined with the building's cooling requirements creates a significant amount of condensation. This water is collected and drained in a separate piping system to a holding tank in the basement car park
• The condensate collection system provides about 15 million gallons of supplement water per year, equal to about 20 Olympic-sized swimming pools
• The tower's peak electrical demand is 36mW, equal to about 360,000 100 Watt bulbs operating simultaneously

Fire Safety

Fire safety and speed of evacuation were prime factors in the design of Burj Khalifa. Concrete surrounds all stairwells and the building service and fireman's elevator will have a capacity of 5,500 kg and will be the world's tallest service elevator. Since people can't reasonably be expected to walk down 160 floors, there are pressurized, air-conditioned refuge areas located approximately every 25 floors.

Elevators & Lifts

Burj Khalifa will be home to 57 elevators and 8 escalators The building service/fireman's elevator will have a capacity of 5,500 kg and will be the world's tallest service elevator.

Burj Khalifa will be the first mega-high rise in which certain elevators will be programmed to permit controlled evacuation for certain fire or security events. Burj Khalifa's Observatory elevators are double deck cabs with a capacity for 12-14 people per cab. Traveling at 10 metres per second, they will have the world's longest travel distance from lowest to highest stop.

THE PARK

Inspired by Burj Khalifa's unique triple-lobed shape, The Park's 11 hectares of greenery and water features serve as both entry to Burj Khalifa and outdoor living space. The landscape design includes three distinct areas to serve each of the tower's three uses: hotel, residential and office space. These exquisite grounds include a promenade along the Dubai lake, outdoor spaces, outdoor dining, prow lookout, leisure forest grove, playing area, water features and much more.

The three spaces are located at the hotel entry, residential entry and the grand terrace. The tower and pedestrian pathways link the three areas. Spectacular stone paving patterns welcome visitors at each entry. The main entry drive is circled with a palm court, water features, outdoor spaces and a forest grove above. The grand terrace features garden spaces, all-around pedestrian circulation, custom site furnishings, a functional island and a lake edge promenade. The grand water terrace is composed of several levels that step down towards the lake's edge. The water terraces provide further visual interest by reflecting the tower on their surfaces. The landscape design includes six major water features: the main entry fountain, hotel entry fountain, residential entry fountain, the grand water terrace, children's fountain pool and the sculptural fountain.

 Green Irrigation

The gardens are partly irrigated with water collected through Burj Khalifa’s Condensate Collection System. Hot and humid Dubai outside air, combined with the tower’s cooling requirements result in a significant amount of condensation of moisture from the air. This water, stored in the basement car park, provides about 15 million gallons of supplemental water per year, the equivalent to nearly 20 Olympic-sized swimming pools.