Axisymmetric large-strain consolidation model for dredged clay with high water content

Large strain generally occurs in dredged clay with high water content under external loading. The traditional axisymmetric small-strain consolidation theory developed by Barron is no longer applicable. Based on the Gibson large-strain consolidation theory and the Hansbo equal-strain consolidation theory, the axisymmetric large strain consolidation (ALSC) model is established under equal strain. ALSC accounts for radial and vertical flows and variation of compressibility and permeability of dredged clay with high water content. The equations established by Gibson, Hansbo and Kjellman are the special cases of ALSC. Based on the finite difference method, the calculation program for ALSC is compiled. The ALSC model and the small-strain model are simulated, and the validity of ALSC is verified. The results show that when the soil deformation is small, the predicted consolidation degree and the excess pore water pressure results of ALSC model are in good agreement with the Barron ones. When the soil deformation is large, the final settlement and consolidation rate of ALSC model and “Barron+Terzaghi” model depend on soil parameters. When C_c/C_k=1, the final settlement of ALSC model is less than that of “Barron+Terzaghi” model, but the consolidation rate is relatively the same. If the compression coefficient a_v remains unchanged during consolidation process, the final settlement is larger but the consolidation rate is slower for ALSC model (C_k =1) than the ones for “Barron+ Terzaghi” model.