粗粒土与结构接触面单调力学特性的试验研究

使用新研制的大型土与结构接触面循环加载剪切仪,对粗粒土与人工粗糙钢板接触面在单调荷载作用下的力学特性进行了较系统的试验研究。从宏观和细观两个角度进行了测量,分析总结了粗粒土与结构接触面的基本力学特性和受力变形机理。试验表明:接触面的厚度约为5～6倍的平均粒径;接触面受剪时表现出明显的相对法向位移,其变化趋势与法向应力有关;接触面的变形可分解为同时发生、互相影响的土与结构交界面上的滑移变形以及结构面附近的土在结构面约束之下的剪切变形两部分,而后者是引起相对法向位移的主要原因;结构面粗糙度、土的种类和法向应力等因素对接触面的力学特性具有重要影响。

Experimental study on monotonic behavior of interface between soil and structure

A series of systematic tests was performed to study the monotonic behavior of interface between coarse-grained soil and structure with a new apparatus called TH-20t Cyclic Shear Apparatus for Soil-Structure Interface (TH-20t CSASSI). The behavior of the interface was recorded and analyzed through both macro- and micro-approaches and the mechanism of the interface was investigated. As a result, new behaviors of the interface between coarse-grained soil and structure were discovered, including: 1) the thickness of the interface that is five to six times the average grain size of the soil; 2) the obvious normal displacement due to shearing, which is affected by normal stress; 3) two shear deformation components due to sliding and constraint of the structural surface relative to the soil respectively, which forms the deformation of the interface; 4) the main factors affecting behavior of the interface including roughness of structural surface, behavior of soil and normal stress.