The Most Tilted Engineered Structure on the Planet

The Most Tilted Engineered Structure on the Planet

“Capital Gate-Abu Dhabi”

Location: Abu Dhabi Completed: 2011 Height: 165 m (540 ft) Stories: 36 Floor area:53100 m2 Primary Use: Hotel & Office

The Capital Gate is one of the tallest buildings in Abu Dhabi designed to tilt /incline about 18^o   towards west which is more than four times the “Leaning tower of Pisa”

Plans were developed with RMJM to build a state-of-the-art exhibition center in the Gulf region and provide world class facilities for live events to flourish in Abu Dhabi.

Guinness World Records certified the Capital Gate as "World's furthest leaning man-made tower" in June 2010

 Design Features

·        The gravitational pressure caused by the 18° tilt is countered by a technique called Pre Cambering, using a core of concrete reinforced in steel

·        The structure is anchored to the ground by 490 piles which are drilled 20 to 30m underground.The piles which are in compression during the construction to support lower floors of building are now in tension due to stresses brought about by the overhang.

·        Tower has very unique horizontal and vertical cross sections. It has an asymmetric shape i.e no two rooms are the same. Every one of the 12,500 glass panels on the facade is of different size, although each panel is triangular in shape.

·        Floor plates change the  shape and orientation in order to create the distinctive “overhang” moving from “curved triangular” to “curved rectangular,” while increasing in overall size and migrating from east to west as they progress up the tower.

·        Capital Gate is one of the few structures in the world that use a diagrid structure system with  two diagrid systems, an internal diagrid linked to the central core by eight unique pin-jointed structural members and

an external diagrid defining the tower’s shape

·        All the 8,250 steel diagrid members have different orientation, thicknesses, & lengths.

·        The post-tensioned core was designed with vertical cables in one side tensioned to counteract the lean on the other side. These cables overlap each other every seven floors. Combined together, they span the entire height of the core to maintain the verticality. 

·        The Capital Gate’s wind resisting system is designed as a separate system. Since Abu Dhabi has light winds, Capital Gate counteracts it by using a combination of a dense network of core walls and outriggers at the 17th floor mechanical level which connects the core to the external diagrid. Capital Gate’s round form and diagrid structure provide excellent resistance to torsion.

·        At the ground floor, a massive concrete ring beam is used to transfer thrust of the diagrid into the foundations.