Capital Gate Tower in Abu Dhabi certified world's furthest leaning manmade tower
The Capital Gate tower in Abu Dhabi has been certified as the world’s ‘furthest leaning manmade tower’ by the Guinness World Records.
The certification comes after months of strict evaluation by a Guinness committee that started in January upon completion of the exterior of the 35-story tower. The 160-meter high tower leans at an angle of 18 degrees, more than 4 times the angle of the Italy’s Leaning Tower of Pisa. Abu Dhabi National Exhibitions Company is the owner and developer of the tower. The tower is designed by international architectural firm RMJM and is slated to be completed by 2010. The tower is being built using many innovative techniques that contribute to its unique shape and strength.
Capital Gate integrates several sustainability features. The tower sports a double-glazed façade that facilitates greater energy efficiency. This is due to the air being pre-cooled between the inner and outer facades before being expelled. Also, low-emissivity glass, being used for the first time in the UAE, keeps the building’s interior cool while maintaining transparency and eliminating glare. The building also features a unique stainless steel ‘splash’ descending from the nineteenth floor. This ‘splash acts as a design element as well as a shading device that eliminates 30% of the sun’s heat before it can reach the building. The ‘splash’ also twists around the building towards the south providing the tower maximum protection from sunlight.
The tower is being built using a special engineering breakthrough that allow floor plates until the twelfth floor to be stacked vertically, after which they are staggered over each other. This staggered design gives the tower its dramatic tilt.
Another innovative construction technique used is the utilization of a pre-cambered core. This is said to be the first time such a technique has been used. The pre-cambered core uses 15,000 cubic meters of concrete reinforced with 10,000 cubic meters of steel. The core is built marginally off-center, straightening along the length of the building, compressing the concrete and giving it strength, and moving into vertical position with the increasing weight of the floors. It is also useful in tackling the pressure exerted by gravity on the 18-degree incline.
Capital Gate also features a special exo-skeleton or diagrid to cope with wind and seismic forces and its inclination. The diagrid design means that each and every element of the grid or the exo-skeleton is in perfect symmetry. The diagrid carries the weight of all the floors while also providing an unobstructed floor plate, eliminating the need for pillars or internal beams. The design has been previously used in only a handful of buildings around the world and it is certainly the first time that such a design is being used in the Middle East.
A cantilevered tea-lounge, hanging over the tower’s exterior, 80 meters above the ground is another unique feature of the Capital Gate. Capital Gate is slated to play host to the five-star Hyatt Capital Gate hotel apart from 20,000 square meters of office space.
