结构性黄土二元介质本构模型在局部化剪切带中的应用

基于破损力学理论，将结构性黄土抽象成具有一定结构强度的结构块和摩擦带组成的二元介质模型。对结构性黄土体来说，局部化剪切带问题也是土体的破损问题，剪切带萌生发展的实质就是结构块向摩擦带转化的动态过程。应用结构性土的双参数破损率二元介质本构模型，采用数值分析方法模拟了平面应变压缩条件下结构性土中局部化剪切带萌生、扩展的过程，研究了不同缺陷方案下局部化剪切带的形态、特性与规律，发现结构性土中局部化剪切带的发展起初是由一段段不连续的微小局部破坏区域在外荷载逐步作用下渐进扩展连接贯通而形成整体剪切带的破坏形式。二元介质本构模型和常规有限元的结合，形象生动地再现了局部化剪切带萌生、发展的过程。

Application of structural loess binary-medium model to localization shear band

Based on the theory of breakage mechanics,the structural loess is conceptualized as binary-medium model consisting of bonding brick and frictional band.Shear band is structural loess’ breakage,localization band sprout and development is dynamic process that bonding brick is translating into frictional band.Applying the double parameter breakage ratio binary-medium model of structural loess,the process of structural loess localization band sprouting and expanding is simulated with the numerical simulations method,the localization shear band shape,speciality and law under different disfigurement project are studied;it is found that the strain localization on a shear band of structural soil at originally is some sets discontinuous little local breakage area step by step developed,connected and formed the shape of whole destruction with the external load increased.Combining binary-medium model with general finite elements,visual reappeared the course of the local shear band germination and progress.