论文部分内容阅读
在大量旁压试验数据分析的基础上,通过曲线拟合,建立了旁压试验弹塑性阶段曲线的椭圆方程,利用土体SMP屈服准则和Rowe流动法则,推导出土体塑性阶段应力增量与应变增量间关系矩阵。在弹性阶段,假设土体应力-应变服从广义虎克定律,建立了基于旁压试验的土体弹塑性本构模型。编制了相应的计算程序,将文中模型计算结果与实际旁压试验曲线进行对比,初步验证了模型的正确性。将本构模型编译为ABAQUS自定义材料子程序UMAT,通过有限元对比分析,文中模型计算变形较弹性模型小,较摩尔-库仑模型大,与模型建立的假设一致。基于旁压试验的土体弹塑性本构模型参数少,且易于获取,便于在实际工程中应用。
Based on the analysis of a large number of lateral pressure test data, the elliptic equation of the elastic-plastic phase curve of the pressure-difference test is established by curve fitting. The SMP yield criterion and Rowe flow rule of soil are used to deduce the stress increment and strain Incremental Relationship Matrix. In the elastic phase, the stress-strain of soil is assumed to be generalized Hooke’s law, and the elastoplastic constitutive model of soil is established based on the pressure-difference test. The corresponding calculation program is compiled and the model calculation results in this paper are compared with the actual pressure-test curve to verify the correctness of the model. The constitutive model was compiled into ABAQUS custom material subroutine UMAT. Through comparative analysis of finite element method, the model calculation deformation in this paper is smaller than the elastic model, larger than that of the Mohr-Coulomb model, which is consistent with the assumption of the model. The elasto-plastic constitutive model of soil based on the pressure-reduction test has less parameters and is easy to acquire, so it is easy to be applied in practical engineering.