The Abu Dhabi branch of Bauer Spezialtiefbau, a leading German geotechnical and foundation specialist, has just completed the foundation works involved for Al Bustan Complex, a multi-use commercial and residential development in the UAE capital.

The project, which was awarded in December 2007, was successfully completed ahead of schedule by last month. The client on the project is Al Hamed Development, Cox Group is the consulting engineer and Cansult is the project manger.
Bauer’s UAE branches have been involved in the design and execution of the deep foundation system and retaining structures of many mega development projects while providing complete and viable construction solutions to its customers in the emirates.
“Our scope of work on the Al Bustan project involved the design and execution of a proper shoring system to retain a 21-m-deep excavation pit, which is one of the deepest with a secant pile wall in the UAE,” says a spokesperson for the company. “The unique design consists of a 1.2-m-diameter secant pile wall with two layers of underwater anchors. On one side, a 1.5-m-diameter secant pile wall with three layers of underwater anchors have been installed to support the addition load of an existing building next to the secant pile wall.”
The excavation, dewatering and monitoring of the movement of secant pile wall was also carried out as was the design and execution of around 900 bored piles of 900 mm diameter and up to 36 m deep. 
An extensive programme of testing on piles was also implemented in order to confirm the compliance and suitability of the designed piles which included calliper logging tests to verify the pile diameter, static load testing, O’Cell – lift jack testing and dynamic load testing and integrity testing among others. In order to check the water level and water pressure outside the secant pile wall, stand pipe pieztometers with vibrating wire gauges were installed around the periphery of the site.
The Al Bustan comprises a four-star business hotel, serviced and unfurnished apartments, commercial offices and retail and food outlets. The project has five towers up to 16 floors above a five-level basement accommodating retail and parking for 2,000 cars and is located adjacent to the Airport Road in Abu Dhabi.