土-混凝土接触面特性环剪单剪试验比较研究

Comparison of behaviors of soil-concrete interface from ring-shear and simple shear tests

对可用于接触面应力变形及强度特性试验的直剪仪、单剪仪及环剪仪的优缺点进行了比较分析。对某土料与混凝土接触面的应力-变形及强度特性进行了单剪试验研究,试验包括土-混凝土接触面及土-泥皮-混凝土接触面两种。同时,将已有的环剪试验成果与单剪试验结果进行了比较分析。研究了环剪试验与单剪试验成果的差异。结果表明,单剪试验测得的抗剪强度比环剪试验测得的低30%～40%,环剪试验用于接触面强度特性研究较合适,而单剪试验用于较低应力水平下的应力-变形试验更好,泥皮的存在使得接触面强度降低30%左右。

The advantages and disadvantages were pointed out by comparing the apparatus including direct shear apparatus,simple shear apparatus and ring shear apparatus,which are commonly used to study the deformation and strength behaviour of the interface.The deformation and strength behavior of the interfaces between a soil and concrete are investigated by using simple shear test.The interfaces include two types,i.e.interface between soil and concrete,and that of soil-mudcake-concrete.The existing results of ring shear tests from references are employed to compare with those from simple shear tests in this paper;and the differences between them are investigated.The results show that the shear strength measured in simple shear test is smaller about 30%-40% than that found in ring shear test.It is pointed out that the ring shear test is more suitable for studying the strength behavior of interface;and the simple shear test,however,is better for investigating the behavior of stress and strain under lower stress level.The strength of interface decreases about 30% due to the existence of mudcake between soil and concrete.