Assessment and analysis of Queensland clay behaviour

Within the past few decades, increased population and infrastructure development has necessitated the reclamation and development of previously undesirable sites for civil engineering works. In Australia, significant development has taken place along the Eastern coastal belt. This region is lined with saturated clays of significant depths (15 m to 20 m) which are typically characterized by high compressibility, low bearing capacity, and high lateral displacement upon loading. The most common and economically viable technique for soil improvement of these foundations is the use prefabricated vertical drains (PVD) in conjunction with preloading. This method accelerates the consolidation process by shortening the drainage path of the soil in the radial direction, and has been used in a number of large projects including the Muar Plains Trial Embankments, Changi East Reclamation Project and the 2nd International Bangkok Airport. Nevertheless, there are very limited case studies of soft clay projects in Australia. General theory of soil behaviour is well established based on the broad classifications of granular and cohesive soils. . However, due to the innumerable environmental and physical processes a soil may be exposed to during its formation, there is natural variance in soil properties. Thus, a holistic approach is advocated for geotechnical calculations at any site. The design methods should be used together with field observations, as well as data obtained from in situ and laboratory testing. When examining the deformation behaviour of clays, engineers are interested not only in the consolidation and compressibility characteristics of a soil, but also the index properties of it. The index properties of a soil describe certain critical stages in soil behaviour, and also the consistency of a soil. Within this dissertation, the index properties of soils from a number of different sites around Queensland have been tested within the laboratory, and analysed statistically. Beta distributions have been Further to ...