修正双屈服面模型在软土基坑开挖中的应用

Application of modified double-yield surface model in foundation excavation of soft soil

将修正塑性功为硬化参数的双屈服面模型引入到上海软土基坑工程的计算分析中,在上海软土的三轴固结不排水试验结果和等向压缩试验结果的基础上,对该模型中弹性部分和塑性剪切部分表达式的形式和参数进行修正和简化。最后将修正后的双屈服面模型应用到基坑开挖程序中,选取3类典型基坑工程,并将计算的结果和实测结果进行比较。结果表明,基坑开挖程序的计算值与实测值比较吻合,该模型在上海软土基坑开挖计算中具有较好的适用性。

In this paper,the double yield surface model with modified plastic work as hardening parameter is introduced into the analysis of Shanghai soft soil foundation pit.Based on experimental data from triaxial consolidation undrained tests and isotropic tests of the Shanghai soft soil,the expression and parameters of elastic part and plastic shear part of the model are modified.The modified model are applied to analysis of soft soil foundation pit engineering in Shanghai soft soil,and three typical foundation pit engineering are selected.Comparing the calculated results with the measured ones,the calculated values are in good agreement with the measured values.The model has good applicability in excavation calculation of soft soil foundation pit in Shanghai.