PILED RAFT DESIGN PROCESS FOR A HIGH-RISE BUILDING ON THE GOLD COAST,

This paper describes the process of design of a piled raft foundation for a high rise residential building on the Gold Coast in Queensland, Australia. The design process comprised an initial stage of geotechnical site characterization using the results of a series of investigation boreholes to prepare a subsurface model and derive geotechnical parameters for raft and pile design from empirical correlations. Following this a preliminary analysis was undertaken using a combination of elastic theory and allowances for non linear behaviour of the piled raft system to assess the viability of such a foundation system and any potential advantages of a piled raft over conventional fully piled foundation systems. Finally, a detailed analysis was undertaken using the GARP8 computer program. These detailed analyses were used to design a more efficient piled raft system and to provide design actions for structural design of the foundation system for a variety of load combinations. 1