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| An analytical solution for one-dimensional nonlinear large-strain consolidation of soft clay with high compressibility |
| LI Chuanxun,QIU Chao |
| (Faculty of Civil Engineering and Mechanics,Jiangsu University,Zhenjiang,Jiangsu 212013,China) |
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Abstract Aiming at the status that some one-dimensional large strain consolidation analytical solutions fail to fully consider the non-linear compression and permeability characteristics of soft soils,in this paper,data analysis of large numbers of laboratory compressibility and permeability tests was conducted, showing that there are good linear relationships between the void ratio with the effective stress and the permeability coefficient in the bi-logarithmic coordinate system,and the variation ranges of parameters for the bi-logarithmic model were also provided. The nonlinear compressibility and permeability model in the bi-logarithmic coordinate system can not only effectively describe the nonlinear consolidation characteristics of soft soils under the condition of small strain,but also reliably reflect the compression and permeability characteristics of soft soils under the condition of large strain. Based on the nonlinear compressibility and permeability model in the bi-logarithmic coordinate system,a one-dimensional nonlinear large-strain consolidation model for thin soft soil layer was developed in the Lagrangian coordinate system by considering the excess pore pressure as a variable. Besides,the analytical solutions for the nonlinear large-strain consolidation model under three conditions were derived,respectively. Then,the reliability of the analytical theory was verified by comparing with laboratory test results and finite difference solutions. Finally,the differences in consolidation behaviors between large and small strain consolidation theories under different strain conditions were discussed. It is found that,when the soil strain is about 15%,the deviation from the excess pore pressure between large and small strain consolidation theories can reach 15%,indicating that it¢s rather necessary to use large strain consolidation theory to calculate consolidation when the corresponding soil strain reaches or larger than 15%.
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