小应变亚塑性黏土本构模型在PLAXIS中的实现及应用

Realization and Application of Small Strain Hypoplastic Constitutive Model for Clay in PLAXIS

针对小应变亚塑性黏土本构模型参数物理意义不明确、工程应用困难,基于PLAXIS有限元软件用户自定义材料属性的二次开发接口,自定义本构模型参数,开发小应变亚塑性黏土本构模型子程序,用于模拟分析单调载荷作用下多特蒙德黏土和循环载荷作用下高岭土的变形过程,并与文献试验结果进行对比,验证了子程序的合理性。在此基础上,将开发的子程序模拟分析京张高铁官厅湖段湖相沉积黏土在列车动循环载荷作用下的变形特征。结果表明:随载荷循环次数的增加,湖相沉积黏土变形逐渐增大并趋于稳定,模拟结果较好地体现了黏性土体在循环载荷作用下的基本力学特征,且与试验结果基本一致,验证了二次开发的小应变亚塑性黏土本构模型子程序在实际工程中的适用性。

Aiming at the unclear physical meaning of the parameters of small strain hypoplastic constitutive model for clay and the difficulty of engineering application,the constitutive model parameters were customized,and the subroutine of the small strain hypoplastic constitutive model for clay was developed.It was used to simulate and analyze the deformation process of Dortmund clay under monotonic load and Gaolin clay under cyclic load.Compared with the experimental results in the literature,the rationality of the subroutine was verified.Based on this,the developed subroutine was used to simulate and analyze the deformation characteristics of lacustrine sedimentary clay in Guanting Lake section of Beijing Zhangjiakou high speed railway under train dynamic cyclic load.The results show that with the increase of load cycles,the deformation of lacustrine sedimentary clay gradually increases and tends to be stable.The simulation results can better reflect the basic mechanical characteristics of cohesive soil under cyclic load,and are basically consistent with the test results,which verifies the applicability of the secondary development of small strain sub plastic clay constitutive model subroutine in practical engineering.