平面应变条件下饱和土体分叉后的力学性状  

POST-BIFURCATION RESPONSE OF SATURATED SOILS UNDER PLANE STRAIN CONDITIONS

作　　者：黄茂松[1] 钱建固[1] 

机构地区：[1]同济大学地下建筑与工程系,上海200092

出　　处：《工程力学》2005年第1期48-53,共6页Engineering Mechanics

基　　金：国家自然科学基金资助项目(50179025);高等学校博士学科点专项科研基金资助项目(2000024724);上海市重点学科建设基金资助项目

摘　　要：土坡和挡土墙的应变局部化和渐进破坏分析的一个关键问题是如何合理描述土体分叉后的力学性状,而从试验得到的峰后应力应变关系实际上并不是土体本身的一种真实本构反应。为此,提出了一种描述含剪切带土体宏观力学特性的改进后的复合体理论(或均匀化理论)。结合干密砂以及饱和松砂、中密砂、密砂的平面应变试验结果,验证了该理论框架的合理性。One of the key issues encountered in the strain localization and progressive failure analyses of slopes and retaining structures is how to describe properly the post-bifurcation response of soils. It has been found that the soil response measured globally in biaxial and triaxial tests may not be a unique material property of soils. It is therefore imperative to understand the post-bifurcation behavior of soils and to correctly simulate this behavior within a suitable mathematic framework. In this paper, the mechanical behavior of saturated soils in the localized mode is estimated through a homogenization technique and the average mechanical properties of a medium are intercepted by a shear band. Numerical predictions of plane strain compression of drained loose sand, untrained loose, medium dense and dense sands are in good agreement with the available biaxial test results.

关 键 词：饱和土体 应变局部化 分叉后 平面应变试验 复合体理论 

分 类 号：TU43[建筑科学—岩土工程]