HIGH RISE BUILDINGS
Tall buildings have a limitation of heights because of vertical transportation. A massive amount of elevators are necessary in the lower part in order to get people up and most of the floor area in lower stories is taken up by this facilities. Around 75% of the lower floors in Burj al Arab are taken up by elevators, stairs, columns and services.
The major structural issue of a skyscraper lies more in the treatment of horizontal stresses than in vertical loads, due to enormous bending moments caused by wind and earthquake forces. Conventional skyscrapers have a central core, which take care of the vertical circulation in terms of elevators, staircases and duct shafts for air-conditioning and other services.
All vertical and horizontal loads are taken care of by a peripheral column system and horizontal platforms between these structures. For this reason the structural safety and economic efficiency of the whole system is dramatically enhanced as the bending moment is reduced. Vertical transportation is not in one core any more, but distributed to the structural elements at the perimeter, offering a variety of building access and especially emergency exit possibilities from the building. The space, which is formed by the geometry of the superstructure, can be now utilized for functions requiring larger, uninterrupted spaces, such as theaters, sports facilities, restaurants etc.