Consolidation analyses of PVD-improved marine clay considering long-term natural sedimentation

Abstract

An analytical solution is derived to calculation the consolidation of marine clay improved by vertical drains under long-term natural sedimentation conditions based on Gibson's one-dimensional consolidation theory and Barron's free-strain theory. The model tests are conducted to verify the accuracy of the proposed theoretical model. Fair agreements between the results from laboratory tests and proposed theory verified it accuracy. Parametric studies are also conducted to investigate the effects of the clay deposition properties and time-dependent sedimentation rates on the consolidation of the marine clay. Under the selected parameter conditions in this article, for the deposition rate of clay deposition layer, k/(2Ch)=1, the maximum of excess pore water pressure keeps stable and is close to 6 kPa. The maximum difference in excess pore water pressure at the bottom of clay deposition layer is approximately 40.1 kPa under two conditions of deposition rate of 0.5 and 10. The average degree of consolidation U of the soil layer after 100 and 200 days of sedimentations are 86 % and 97 %, respectively.