Mechanics of the consolidation of a lumpy soft clay fill

Abstract

Large quantities of lumpy materials are generated from dredging, excavation and tunneling works. The disposal of these materials poses a severe problem in land-scarce Singapore. This thesis addresses the consolidation problems encountered when this type of soils is used as a fill. The double porosity theory was adopted to describe the consolidation and a box-spring analogy was used to provide a better understanding. The theory was derived using a two-phase flow analogy with self-weight included. Using the analytical solution, salient features of consolidation were demonstrated by parametric analysis. In reality, the behaviour of lumpy clay was highly non-linear, and a finite element program was developed to solve the non-linearities. The model predicted well the measured settlement and pore pressures of two sets of tests. This indicates that the model is able to represent the essence of the mechanics of consolidation of the lumpy clay fill.