Analysis of Settlement Induced by Dissipation of the Excess Pore Water Pressure Due to Piling in Soft Clay

Consolidation settlement induced by dissipation of the excess pore water pressure due to pilling in soft clay and negative skin friction caused by it were analyzed. Piling or the pile driving process usually induces excess pore water pressure in the surrounding soil. When this excess water pressure dissipates later on after the pile driving process is complete, settlement of the surrounding soil occurs and a negative skin resistance along the pile shaft develops, which is undesirable. In this paper, three-dimensional Biot's consolidation theory was introduced into FEM analysis to take into account the nonlinear consolidation behavior of the soil. The pile-driving process was defined and analyzed in terms of the expansion in a cylindrical cavity. In general, the results based on the FEM method and 3D Biot's theory were consistent with the actual field measurements on site; with an even better accuracy than the results computed based on Tergazhi's theory. Therefore, the method proposed in this paper is rational and exhibits greater promising potential for application in engineering designs.