Earth retaining structures in Perth, Western Australia

This paper provides a brief description of the ground strata and ground water conditions commonly encountered in excavations in and around the CBD and residential areas near Perth, WA. The particular implications of these conditions on the selection, design and performance of conventional and locally developed retaining wall systems are addressed to provide guidance in the identification of the most appropriate system for future excavation projects. A summary of the retaining wall systems used in Perth is presented, with comments relating to the advantages and limitations of each wall type. Details of a number of case histories are provided to highlight the appropriate use of most of the retaining wall types considered. Reference is made to a cautionary note relating to the inappropriate reliance, by some sectors of the construction industry, on the weak cementing of the near surface Tamala Sands that occurs widely over the Perth Coastal Plain.