一种粗粒土非线性剪胀模型的扩展及其验证

A NONLINEAR DILATANCY MODEL?S EXTENTION AND VALIDATION FOR COARSED-GRAINED SOILS

在次弹性理论基础上,将一种粗粒土的非线性剪胀模型的应力–应变关系式扩展到一般的三维应力条件下,给出三维本构关系的张量形式和矩阵形式以便有限元计算使用。基于ABAQUS平台并利用用户子程序UMAT实现非线性剪胀模型的有限元计算程序。选择某个堆石坝工程的粗粒土为研究对象,应用该程序对粗粒土在不同围压条件下的大型饱和三轴固结排水试验进行三维非线性有限元的数值模拟,并与试验结果进行比较,初步验证本文所推导的三维关系的张量形式和矩阵形式的合理性,以及编制的有限元程序的正确性。

Based on hypoelasticity,three-module incremental nonlinear stress-strain relationships of a nonlinear dilatancy model for coarsed-grained soils under triaxial stress condition is generalized into a three-dimensional stress-strain relationship,and both tensor form and matrix form are given for finite element implementation. The nonlinear dilatancy model is implemented by user subroutine UMAT on ABAQUS finite-element software. The coarsed-grained soils of a rockfill dam sit is selected,conventional large scaled triaxial consolidated drained shear tests under saturated conditions with different confining pressures were calculated by ABAQUS for the coarsed-grained soils,the comparison between calculation results and tests results has been employed to validate the tensor form and matrix form and the subroutine.