【正文】 tlement was 30mm (). The geotechnical studies were peer reviewed by both Mr. Clyde Baker of STS Consultants, Ltd. (Chicago, IL, USA) and by Dr. Harry Poulos of Coffey Geosciences (Sydney, Australia). The groundwater in which the Burj Dubai substructure is constructed is particularly severe, with chloride concentrations of up to %, and sulfates of up to %. The chloride and sulfate concentrations found in the groundwater are even higher than the concentrations in sea water. Accordingly, the primary consideration in designing the piles and raft foundation was durability. The concrete mix for the piles was a 60 MPa mix based on a triple blend with 25% fly ash, 7% silica fume, and a water to cement ratio of . The concrete was also designed as a fully self consolidating concrete, incorporating a viscosity modifying admixture with a slump flow of 675 +/ 75mm to limit the possibility of defects during construction. Due to the aggressive conditions present caused by the extremely corrosive ground water, a rigorous program of anticorrosion measures was required to ensure the durability of the foundations. Measures implemented included specialized waterproofing systems, increased concrete cover, the addition of corrosion inhibitors to the concrete mix. stringent crack control design criteria, and cathodic protection system utilizing titanium mesh (Figure 13) with an impressed current. Wind Engineering For a building of this height and slenderness, wind forces and the resulting motions in the upper levels bee dominant factors in the structural design. An extensive program of wind tunnel tests and other studies were undertaken under the direction of Dr. Peter Irwin of Rowan Williams Davies and Irwin Inc.39。s Elastic Modulus of 43,800 N/mm2 (6,350ksi) at 90 days. The wall and column sizes were optimized using virtual work .39。 Structural System Description Burj Khalifa has refuge floors at 25 to 30 story intervals that are more fire resistant and have separate air supplies in case of emergency. Its reinforced concrete structure makes it stronger than steelframe skyscrapers Designers purposely shaped the structural concrete Burj Dubai Y shaped in plan to reduce the wind forces on the tower, as well as to keep the structure simple and foster constructibility. The structural system can be described as a buttressed core (Figures 1, 2 and 3). Each wing, with its own high performance concrete corridor walls and perimeter columns, buttresses the others via a sixsided central core, or hexagonal hub. The result is a tower that is extremely stiff laterally and torsionally. SOM applied a rigorous geometry to the tower that aligned all the mon central core, wall, and column elements。s highest building: it39。 Architectural Design The context of the Burj Dubai being located in the city of Dubai, UAE, drove the inspiration for the building form to inco