汪优　任加琳　李赛　熊凡

摘   要：结合室内直剪试验分析土与结构接触面的本构关系，研究不同法向应力条件下接触面的变形特征和应力路径，并构建反映土-结构接触面本构关系的数学模型. 试验结果表明：法向应力和界面粗糙度是影响接触面剪切特性的主要因素. 界限法向应力的存在使得剪切破坏模式发生转变，其数值与接触面的粗糙度和土体的相关剪切属性有关. 此外对接触面统计损伤本构模型进行改进，在忽略接触面厚度参数的基础上，结合剪切过程中的"三阶段"模式，提出了考虑接触面剪切全过程的统计损伤改进模型，并通过试验数据验证其正确性. 该模型可以反映一定法向应力情况下土-结构接触面周围的整体变形量.

关键词：土-结构接触面;直剪试验;全过程剪切变形;本构模型

中图分类号：TU443                               文献标志码：A

Study on Shear Constitutive Relation of Soil - structure

Interface in Whole Process

WANG You1?，REN Jialin1，LI Sai2，XIONG Fan1

（1. School of Civil Engineering，Central South University，Changsha 410075，China;

2. Zhuhai Aviation City Engineering Construction Co Ltd，Zhuhai 519000，China）

Abstract：This paper analyzed the constitutive relationship of soil-structure interface，studied the deformation characteristics and stress paths of interface under different normal stresses with laboratory direct shear test，and established a mathematical model reflecting the constitutive relationship of soil-structure interface. The test results show that normal stress and interface roughness are the main factors affecting the shear characteristics of the interface. The shear failure mode of the interface changes due to the existence of consolidation stress. Its value is related to the roughness of the interface and the shear properties of the soil. Moreover，we proposed an improved statistical damaging model considering the whole shear process of the contact surface，based on ignoring the thickness of the interface and combining with the “three-stage” mode of the shear process. The correctness of this improved model is verified by experimental data. Moreover，this model can reflect the global deformation around the soil-structure interface under certain normal stress.

Key words：soil-structure interface;direct shear test;full-process shear deformation;constitutive model

在當今的工程建设中，无论是房屋桥梁的架设还是城市地下空间的开发，都离不开土与结构物之间的相互作用[1-4]，由于土与结构物的材料属性相差悬殊，所以土体与结构物接触面间的力学传递特性和本构行为也一直是当今学者关注和研究的重点，目前土-结构物接触面研究的方法一般为试验研究[5-10]. Potyondy[11]通过剪切试验得出影响结构物接触面剪切强度的主要因素为土体类型、含水率、粗糙度以及法向应力. Tsubakihara等[12]通过黏土与钢板之间的直剪试验得到在剪切过程中的三种破坏形式：接触面处的滑移破坏……