Interview with Assistant Director: Greg Sang
How many workers are on site now?
Currently 3,000 workers, this will increase to 5,000 at the peak of construction.
How many contracting companies are on site?
Over 30
How many cranes have been engaged?
At present there are 10 cranes on the Burj Dubai site.
Safety: Any casualty so far?
Emaar and its contractors follow a strict international standards guide.
What engineering method has been employed?
As for any tall building, wind forces dominate the structural design. Extensive wind tunnel testing, modeling the actual winds the Burj Dubai will experience during its lifetime, has been carried out. The preliminary design was fine tuned in response to the results of the wind tunnel tests.
Typically, what is the life of such a tall building?
Not typical for tall buildings, but the Burj Dubai has been designed to last for at least 100 years.
Can you comment on how life would be "on top of the world"? What sort of people will live in the world's tallest tower?
How do you feel, to be associated with the world's tallest tower, while it is in the making or History Rising?
"It is an honour to be working on a record breaking project and global icon. I am proud to be a part of history in the making and being part of a team that is setting new benchmarks for architecture, pushing engineering and science to new limits and achieving what no other development has."
Interview with the chief engineer
What are the challenges of building such a structure?
How were these challenges addressed?
Extensive analysis, research and tests were carried out at every stage of the project.
What are some of the technical difficulties in building the tallest tower?
In terms of construction of the Burj Dubai, what will happen?
The core was built first using a cantilever system to build out. The core will employ a self-climbing system, allowing the three luffing-jib tower cranes to attend to other picks. As for the spire, a jacking method (similar to the one used on Petronas towers) will be used.
What about safety?
We follow standard international safety regulations necessary for any construction site in addition to any local UAE requirements. In Dubai, the main contractor is required to establish a safety program in line with such requirements and also specifically address issues and implement systems for working on heights, perimeter protection, use of cranes, fire safety and emergency evacuation and so on.
Structural System
The structural system of the Burj Dubai utilizes high performance concrete as its primary material. The tower's lateral load resisting system provides resistance to wind and seismic forces. It is comprised of high-performance, reinforced concrete core walls linked to the exterior columns through a series of reinforced concrete shear wall panels at the mechanical levels.
The typical floor system consists of a reinforced concrete flat plate.
The building's foundation is a thick high performance reinforced concrete mat supported on piles. At the top of the tower, a spire (with occupied space inside) makes the building the tallest tower in the world. The lateral load resisting system of the upper steel structure consists of a structural steel mega-bracing system that is founded on the top of the reinforced concrete core wall.
Article - A Skyscraper in every sense
There has been much speculation with regards to the height of The Burj Dubai, all we haven't announced the official height. At Emaar we view the Tower as an inspiration for each one of us.
Samsung Corporation from South Korea is the main building contractor.
The estimated building cost is US$1billion. The whole Downtown Burj Dubai development will cost circa US$20billion and offer 30,000 homesand the world's largest shopping mall, The Dubai Mall
Many of the tower floors will be occupied by the 175 room Armani Hotel, the first to open. In addition there will be 144 luxury residential suites designed by Giorgio Armani and kitted out with his home furnishing line.
Floors 17 to 108 will have 800 private apartments.
Most of the higher floors will be offices and private suites.
An observatory 442 meters above ground on the 124th floor will be open to the public - the highest publicly accessible observation desk in the world.
There will be a Club on floors 144 to 146
The Tower will be built of glass, aluminum, concrete and steel
The external surface is made of unitized panels made of aluminum, glass and various brackets, they interlock on site and are up to two storeys tall. They improve the quality and speed up building work.
The tip of the spire will be visible 60 miles away.
The rods that reinforce the structure weight a total of 31,400 tonnes and laid end to end would stretch more than a quarter of the way around the world.
The water system will supply about 250,000 gallons per day.
The Tower's external surface is the size of 17 football fields.
The concrete used is equivalent to a solid cube of concrete 61 meters in size or a 1.5 meter wide pavement. 1,200 miles long. It weighs the same as 100,000 elephants
Peak electricity demand of the tower is the same as 360,000 100 watt light bulbs.
Article - Engineering the Structure of the World's Tallest Building
By William F. Baker, C.E., S.E., P.E., FASCE - Structural Engineering Partner (SOM)
The Burj Dubai structure represents the state-of-the-art in tall building design. Once completed, it will be not only the world's tallest building but the tallest man-made structure ever created. From the project's initial concept design through construction, the combination of several important technological innovations results in a building of unprecedented height. The following is a description of some of the innovative structural design methods which enable the creation of a superstructure that is both efficient and robust.
"Designing the Wind"
The primary concern in the engineering of tall buildings is the effect of the wind on the building's structure. The shape of the Burj Dubai is the result of deliberate cooperation between SOM's architects and engineers to vary the shape of the building along its height, thereby minimizing wind forces on the building. In effect, each uniquely-shaped section of the tower causes the wind to behave differently, preventing it from becoming organized and minimizing lateral movement of the structure.
The modular, Y-shaped structure, with setbacks along each of the three wings, was part of the original concept design entered in an invited design competition at the beginning of the project. From this starting point, the SOM team refined the tower's shape over several months of extensive wind tunnel tests. Through these tests, the team determined the harmonic frequency of wind gusts and eddies under various wind conditions. This information was used to set targets for the building's natural frequencies, thereby "tuning" it to minimize the effects of the wind.
Concurrent with the wind tunnel studies, the team performed a detailed climatic study which considered the unique meteorological conditions of the Dubai wind climate. These studies considered both frequently occurring and rare wind events to address occupant comfort and building strength. Together, the wind tunnel testing and climatic studies resulted in a highly engineered solution that is appropriate for the Dubai wind climate.
"Buttressed Core" System
As a residential tower, the Burj Dubai requires floor plates with shallow lease spans that maximize the amount of exterior window area (and therefore natural light) in the living spaces. As a very tall tower, it requires a wide footprint to provide sufficient stability to resist high wind loads. The Y-shaped arrangement of reinforced concrete shear walls around a central hexagonal reinforced concrete core satisfies both of these requirements. The resulting "buttressed core" is an extremely efficient solution to the potentially conflicting structural requirements of a super tall residential tower.
Core walls in each wing are arranged in a 9-meter module that matches the setbacks of the tower. This allows the building to be shaped without transfers; the columns in the nose of each setback sit directly on the walls below. The result is an easily constructed system that is significantly less expensive to build than one requiring transfers.
The perimeter columns on the sides of each wing match the width of the adjacent shear walls, thus permitting them to be engaged by infill walls at each mechanical level. This engagement of the perimeter columns leads to high levels of structural efficiency in resisting loads as well as a high degree of redundancy.
High Performance Materials and Construction Methods
The specified material and the configuration of the structural elements utilize the high performance concrete and formwork systems readily available in Dubai. Very strong, high density concrete composed of Portland cement in combination with silica fume, fly ash, and ground granulated slag is available and results in a structure which is stiff, strong and highly constructible.
Foundations
The superstructure is supported by a large reinforced concrete mat, which is in turn supported by bored reinforced concrete piles. The design of these elements is based on extensive geotechnical and seismic investigations and analysis. The high density and low permeability of the concrete used for the foundations minimize the detrimental effects of high chlorides and sulphate content in the local ground water. The foundations are further protected by waterproofing and cathodic protection systems.
The expected effects of a seismic event on the tower are modest. As is the case with most tall buildings, the long vibration period of the Burj Dubai is quite different from the high frequency vibrations of an earthquake and therefore the structure will not generate large forces in a seismic event.
Extensive Peer Review Process
The Burj Dubai represents a groundbreaking design of an extremely important building. For this reason, the team implemented an extensive program of peer reviews. All major technical aspects of the project were examined by experts in tall building design to confirm the safety and effectiveness of the structural systems. This extensive program included three separate peer review programs on the project's geotechnical engineering, wind engineering/testing and structural engineering.
The Structure of the Burj Dubai
The Burj Dubai structure represents the state-of-the-art in super tall buildings. It capitalizes on the latest advances in wind engineering, structural engineering, structural systems, construction materials and construction methods to result in a structure that goes beyond anything that has been achieved before. The tallest structure ever built, it realizes the aspirations of mankind to reach to the sky.
Article - Designers Skidmore, Owings and Merrill
Design and engineering firm Skidmore, Owings and Merrill (SOM) is no stranger to the creation of skyscrapers, having produced America's tallest building, the Sears Tower in Chicago.
The company also created the 100 storey John Hancock Tower in Chicago and the Bank of America headquarters in San Francisco.
Since its foundation in 1936, the firm has completed more than 10,000 architecture, engineering, interior design and planning projects in over 50 countries.
More than 800 design awards have been given to the practice - more than any other American design firm.
The firm has offices in Chicago, New York, San Francisco, Washington DC, Los Angeles, London, Hong Kong and Shanghai. The Chicago office carried out most of the design work on the Burj Dubai.
Article - Designing for Strong Winds
An important consideration in design was reducing the effect of strong winds, soon after winning the contest to design the Tower, Skidmore, Owings and Merrill experts went into the wind tunnel and reshaped the structure many times. It is designed to withstand the worst storm that could be expected in Dubai in a 100 year period.
William Barker, SOM's partner in charge of structural engineering, explained "When the wind blows past something, it creates whirlwinds that make the building go from side to side. If those movements happen at the natural frequency of the tower, you can get very large forces. We try to break up the natural frequency".
Because the Tower has many different surfaces the wind gets confused so the forces it exerts on the building are reduced. As a result, people inside the tower will not be able to detect any side to side movement.
The Burj Dubai development will single handedly shift Dubai's centre of gravity and become home to more than 100 nationalities and feature some of the world's finest residential, leisure, dining and entertainment options.
Some comments on the safety and security aspect on site, as well as post-handover maintenance.
Given the prominence of the tower, both locally and internationally, it is our intention that the tower be a showpiece, not just when it is completed, but also during its construction. That said, the highest safety standards are in place and are effectively being implemented. We are following the standard international safety regulations necessary for any construction site.
In Dubai, the main contractor is required to establish a safety program in line with such requirements and also specifically address issues and implement systems for working on heights, perimeter protection, use of cranes, working in elevator hoist-ways and service shafts, fire safety and emergency evacuation. We also have an on-site paramedic staffed first aid facilities office.
