Abstract
In Singapore, the uses of clays from marine dredging and land-based construction activities as fill for land reclamation provides a solution to the problem of disposal while turning such waste soils into material of economic value. A major problem with such fill is the very high degree of heterogeneity in the ground formed. The characterization of such ground at different stages of land reclamation works poses a major challenge as many traditional in-situ tests which provide point values are based on solutions essentially based on continuum mechanics. A major site characterization program was carried out as part of a research project. The Radioisotope cone penetration test is employed for site investigation to measure the continuous changes in density together with other usual cone parameters. The tests have been conducted on recently dumped lumpy fill prior to any soil treatment as well as on a newly formed lumpy fill, after a sand cap has been provided. Results from these tests shows that usual CPT parameters coupled with the additional density measurement will provide a much more complete picture of the fill formed. Problems faced in marine based investigations are also presented, and this has led to the development of a new cone.