Soft Clay Properties and Their Influence in Preloading with PVD and Surcharge

Ground improvement techniques are now widely used in soft clays of deltaic, marine and estuarine origin. The water contents of these clays range very widely some time even over 200 percent. Also, some clay has high sensitivity and high organic contents. In addition, geological conditions such as piezometric draw down also have an influence on the method adopted for ground improvement works. In this paper, the role of soil properties, geological conditions and other aspects such as the organic content will be discussed on selected case histories involving ground improvement with surcharge and PVD and other ground improvement schemes. In addition to laboratory methods of determining the soft clay properties, an observational approach in back-calculating soft clay properties from large scaled field tests which form part of the site investigation and construction control program will also be included.