路堤荷载下软土地基蠕变变形性状预测及分析

根据软土的蠕变特性,以有限单元法为分析手段,选用Plaxis软件中能考虑土体黏弹塑性特征的SSC模型,模拟了路堤荷载下软土地基长期变形的过程及性状,同时作为对比,采用不考虑时间效应的SS模型模拟了该问题。计算结果表明,由SSC模型计算的软土地基的沉降、孔压随时间的变化规律均较为合理,而简单弹塑性模型SS的结果则会低估变形水平。此外,SSC模型中的修正蠕变系数μ*对软基长期变形曲线的影响较大。说明今后在预测分析路堤荷载下软土地基的长期变形时,合理考虑软土蠕变特性的关键必要性。

Numerical Simulation and Analysis of Soft Soil Foundation Creep Deformation

According to creep properties of soft soil,the SSC constitutive model in Plaxis is adopted to simulate the viscous-elastic and plastic deformation of soft soil,on the basis of which the long-term behavior of soft soil foundation under the effect of sub-grade loading is simulated with FEM by Plaxis.And for the sake of comparison,the general elastoplastic constitutive model of SS in Plaxis is also used to simulate this problem.It shows that the results of settlement and excess pore pressure of soft foundation simulated by SSC model are reasonable,while the ones simulated by SS model would be underestimated.Moreover,the modified creep index of in SSC model has significant influence on the curvature of deformation curves.In the light of the simulation and analysis above,it is found that appropriate creep properties have to be taken into account when long-term behavior of soft soil foundation is predicted and analyzed.