Saturday, 14 August 2010 at 17:15
BURJ KHALIFA_DUBAI: The completion of the world’s tallest skyscraper (2717 feet) more than 1000 feet taller than second tallest Taipei101 building, easily more than two Empire State Buildings. It is unrealistic to insist on passive solar cooling in a climate where summer temperatures hit 120 degree Fahrenheit and even the bus shelters are air-conditioned. Low-E antiglare glass panels were used in exterior. The sheen of the vertical stainless steel, especially in the horizontal sun of morning and evenings, makes the building sings.
The tower used over 430,000 cubic yards of concrete and 43,000 tons of steel rebar to help determine the concrete-to-rebar ratio, three-dimensional finite element analysis models were used to predict the effects of creep and shrinking.
Seven two-to-three story high mechanical floors are distributed throughout the building about every thirty (30) floors or so. It is really a thirty (30) story building stacked on top of one another. There would be too much pressure to the pipes, and ducts would get too big if try to move things too far.
Mechanical floors house various equipments, including water tanks and pumps, air handling units, and electrical substations. Rack-mounted building-maintenance units, used for window washing, are stored in garages within the structure.
Dubai has sand problems. It sticks to everything. Window washing is expected to take place every few months.
There is a tremendous amount of pressure in a building of this height, both on the water side and on the air side.
The typical system pressure for water is 300psi. The Burj has one of the highest water pressures in the world @ up to 460psi. Imagine water pipes that is 2625 feet tall, and you do not want to be standing under that.
Pressure breaks are typically added in high-rise buildings to alleviate the forces. In the Burj, Skidmore, Owens and Merrill (SOM) created some of the highest pressure breaks ever in a building, consisting mainly of heat exchangers to isolate one riser from another. The tower’s water system supplies an average of 250,000 gallons of water daily.
Cooling the water presented another challenge for SOM’s engineers in Dubai. Hot water was very hot and that of cold water also was very hot in hotels. Imagine getting hot water out of the cold faucet at the Armani Hotel in the Burj.
Since Dubai is limited fresh water and relies on the sea, the water had to travel through the very hot ground during the salt evaporation process. Instead of following that scenario, SOM took advantage of the area’s high humidity and the large amount of condensation that results, the moisture is so high that you collect condensate in the air during a cooling period; you get a significant amount of water in the 55-65 degree Fahrenheit range. This water is collected and drained in separate piping system to a holding tank. The system provides about fifteen (15) million gallons of supplemental water per year.
Burj contains fastest elevator system in the world. The longest elevator ride takes only two (2) minutes
It is half mile high. Let's say 14ft per floor there will be 200 floors.
ReplyDeleteSaudi are building mile high (over 5000ft) tower. Japan is planning two mile high (over 10000ft) tower in Tokyo overlooking Mt Fuji. Incredible engineering feat esp area like in Japan, there are quite several active volcanoes and earthquakes.