Burj Khalifa – World’s Tallest Building
- Official Name: Burj Khalifa Bin Zayed
- Also Known As: Burj Dubai
- Also Known As: Tower Of Khalifa
- Formerly: Burj Dubai
- Built: 2004-2010
- Cost: $4,100,000,000
- Designed By: Skidmore, Owings & Merrill
- Type: Skyscraper
- Stories: 206
- Maximum Height: 2,717 Feet / 828 Meters
- Location: No. 1, Burj Dubai Boulevard, Dubai, United Arab
Site Plan – Burj Khalifa
Structure In General
- Construction Type: Skyscraper
- Current Status: Existing [Completed]
- Structural System: Buttressed Core
- Structural Material: Concrete, Steel
- Facade Material: Stainless Steel
- Facade System: Curtain Wall
- Architectural Style: Modernism
- Floor Plan: 517,240m2
- Order Year: 2003
- Construction Start: 2004
- Project Type: Mall, Residential And Retail Facilities And World’s Tallest Skyscraper
- Location: Dubai, United Arab Emirates
- Estimated Investment: Aed800m (Mall, Residential And Retail Facilities); Aed3.9bn (Tower); Overall Development $8bn
- Completion: 2008 (Mall); 2008 (Tower), Mall Opening On 31st August 2008, Tower Officially Opened 4 January 2010
- Retail Space: 9 Million Square Feet
Building a Global Icon
Excavation work began 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’sTallest 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 Dubai Tops Out|
|September 2009||Exterior Cladding Completed|
|January 2010||Official Launch Ceremony|
Built Around The Burj
Downtown Burj Dubai Is A Mixed Development Including 30,000 Homes, Nine Hotels, 2.4 Hectares Of Parkland, 19 Residential Towers And The 12-hectare Burj Dubai Lake.
- 8 Boulevard Walk
- Boulevard Crescents
- Boulevard Plaza: 36-storey Commercial Offices
- Burj Dubai Boulevard
- Dubai Mall: World’s Largest Shopping Centre
- Emaar Square Business Hub
- Lake Park
- Old Town
- Old Town Island
- The Address, Dubai Mall Hotel
- The Residences
Some Interesting Facts About The Burj Dubai
- Although the building’s shape resembles the bundled tube concept of the Willis Tower, it is structurally very different and is technically not a tube structure.
- The tower is situated on a man-made lake which is designed to wrap around the tower and to provide dramatic views of it.
- The elevators have the world’s longest travel distance from lowest to highest stop.
- Hot air on the outside condense due to the large cooling needs of the building. The condensation is collected and used to water the buildings flora and fauna. 20 Olympic-sized swimming pools per year of water.
- There are 1,210 fire extinguishers on the site.
- At the peak cooling times, the tower require approximately 10,000 tons of cooling per hour.
- The tower’s observation deck is located 442 metres above ground, the highest publicly accessible observation deck in the world.
- Condensation on the building is collected and drained down to a holding tank located in the basement from where it is pumped into the site irrigation system for use on the tower’s landscaped gardens. This system provide about 15 million gallons of supplemental water per year, equivalent to nearly 20 olympic-sized swimming pools.
- Engineers working on the design considered installing triple-decker elevators, which would have been the first in the world. In fact, the realized building uses double-decker elevators.
- The amount of steel rebar used for the tower is 31,400 metric tons – laid end to end this would extend over a quarter of the way around the world.
- Over 330,000 cubic meters of concrete was used at the completion of the tower.
- Dubai has set a new world record for vertical concrete pumping for a building, by pumping to over 460 metres. The previous record was held by Taipei 101 for pumping concrete up to a height of 448 metres.
- Burj Dubai break the world record for altitude transportation of concrete
- The total area of cladding used to cover the Burj Dubai is equivalent to 17 football fields.
- The concrete used for the Burj Dubai is equivalent to: a solid cube of concrete 61 metres on a side, a sidewalk 1,900 kilometres long, the weight of 100,000 elephants.
- The tower’s peak electricity demand is estimated at 36mva, equivalent to roughly 360,000 100-watt light bulbs.
- There are 200 metres of dancing fountains at the foot of the Burj Dubai.
- The Burj Dubai feature the world’s first Armani Hotel.
- Burj Dubai derives its design inspiration from the desert flower, hymenocalis, and incorporates patterning systems that are embodied in Islamic architecture.
- At 5,500 kg capacity, the firemen/service elevator is the world’s tallest service elevator.
- First mega-rise to have elevators with specially programmed, permit-controlled evacuation procedures.
- The total glass requirement is 142k sq/m
- The car park has approx. 3,000 parking places in four levels and a total area of just under 89,000 m2.
- The car park ventilation system is comply with the US Standards Ashrae and Amca for air quality and fan requirements and in case of fire it is suitable for operating at 300°c for not less than 60 minutes.
- The building was rotated 120 degrees to allow for less stress from the prevailing winds.
- The building sits on a concrete and steel podium with 192 piles descending to a depth of more than 50 metres (164 feet).
- A total of 45,000 cubic metres of concrete are used in the foundations with a weight in excess of 110,000 tons.
- The double deck cabin elevators are the fatest in the world and also the one to travel the longest from a lower to higher point. The speed of the cabin is 18 m/sec (40 mph).
- It also has the worlds first programmed and controlled evacuation in the world.
- It can withstand the worst storm to hit Dubai in a 100 years
- It has 15,000 sq ft of fitness facilities.
- Connected to the largest mall in the world.
The following is a breakdown of floors:
|160 And Above||Mechanical|
|156-159||Communication and Broadcast|
|124||At The Top Observatory|
|38-39||Armani Hotel Suites|
|B1- B2||Parking, Mechanical|
Burj Khalifa In Numbers
- 95: Distance In Km At Which Its Spire Can Be Seen
- 504: Rise In Metres Of Its Main Service Lift
- 57: Number Of Lifts
- 49: Number Of Office Floors
- 1,044: Number Of Residential Apartments
- 900: Length In Feet Of The Fountain At The Foot Of The Tower, The World’s Tallest Performing Fountain
- 28,261: Number Of Glass Cladding Panels On The Exterior Of The Tower
- 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 Dubai is evocative of the onion domes prevalent in Islamic Architecture.
- The Y-shaped plan is ideal for residential and hotel usage, with the wings allowing maximum outward views and inward natural light.
- 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 minimum centre-to-centre spacing of the piles for the tower is 2.5 times the pile diameter.
- 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.
- 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 the Armani Hotel at Level 1.
- The structure is modular in nature with a central hexagonal shaft or core and three branches that spread out at 120 degrees from each other.
- Attached to these branches are wall like columns at 9 meter spacing that simply drop off as each leg sets back, avoiding complex and costly structural transfers.
- 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.
- The center hexagonal reinforced concrete core walls provide the torsional resistance of the structure similar to a closed tube or axle.
- The center hexagonal walls are buttressed by the wing walls and hammer head walls which behave as the webs and flanges of a beam to resist the wind shears and moments.
- Outriggers at the mechanical floors allow the 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 wall concrete specified strengths ranged from C80 to C60 cube strength and utilized portland cement and fly ash.
- Local aggregates were utilized for the concrete mix design.
- The C80 concrete for the lower portion of the structure had a specified young’s elastic modulus
of 43,800 n/mm2 (6,350ksi) at 90 days.
- The wall and column sizes were optimized using virtual work / lagrange multiplier methodology which results in a very efficient structure.
- 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.
- 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.
- 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 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 can measure approximately 15 meters.
- Under normal conditions, with all building maintenance units in operation, it takes 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 consultant.
- 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 have a capacity of 5,500 kg and is 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 is home to 57 elevators and 8 escalators the building service/fireman’s elevator have a capacity of 5,500 kg and is the world’s tallest service elevator.
- Burj Khalifa is the first mega-high rise in which certain elevators are 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 are the world’s longest travel distance from lowest to highest stop.
Wind Tunnel Testing
- Over 40 wind tunnel tests were conducted on Burj Dubai 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 Dubai to determine the magnitude of the changes that would have to be dealt with in the building design
- The interior design of Burj Dubai 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 cultural while staying mindful of the building’s status as a global icon and residence.
- 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 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.
- 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.
- Burj Dubai has been designed to be the centerpiece of a large-scale, mixed-use development that will include 30,000 homes, nine hotels such as the Burj Dubai Lake Hotel & Serviced Apartments, 0.03 km² (0.01 sq mi) of parkland, at least 19 residential towers, the Dubai Mall, and the 0.12 km² (0.05 sq mi) man-made Burj Dubai lake.
- Burj Dubai cost US$ 800 million to build and the entire 2 km² (0.77 sq mi) development cost around US$ 20 billion.
- The silvery glass-sheathed concrete building gives the title of earth’s tallest free-standing structure to the Middle East — a title not held by the region since 1311 AD when Lincoln Cathedral in England surpassed the height of the Great Pyramid of Giza, which had held the title for almost four millennia.
- The decision to build Burj Dubai is reportedly based on the government’s decision to diversify from a trade-based economy to one that is service- and tourism-oriented.
- According to officials, it is necessary for projects like Burj Dubai to be built in the city to garner more international recognition, and hence investment. “He [Sheikh Mohammed Bin Rashid Al Maktoum] wanted to put Dubai on the map with something really sensational,” said Jacqui Josephson, a Tourism and VIP Delegations Executive at Nakheel Properties.
“Burj Khalifa is the Arab World’s tribute to the Art and Science of Modern Engineering and Design. Burj Khalifa symbolizes the aesthetic unison of many cultures – from Arabia and the rest of the world.” – Mohamed Alabbar (Chairman, Emaar)
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