A study on building foundations in Perth CBD

In the past decade, numbers of high rise buildings in Perth CBD are increasing rapidly and, due to increase in the height, problems associated with foundations have become more apparent than before. The paper will present a study of buildings foundation in the city of Perth which have been designed and built in the recent years. The study focuses on the factors governing the design and the selection of raft, pile and piled raft. In addition, problems encountered during the constructions of foundation of three high rise buildings in Perth CBD will be presented. A comparison of foundation systems amongst these buildings will be made in terms of soil condition, cost and construction features. Based on an estimated cost of the foundations, piled raft foundation is an economical option and addition of limited number of piles will reduce the maximum settlements, differential settlements and the required thickness of the foundation. With constructability issues, it is found that the presence of water, utilities services and the ground anchors from the surrounding buildings are the major problems encountered during the construction of foundations.