EXPERIMENTAL RESEARCH ON SHEAR CHARACTERISTICS OF MUD-FILLED STRUCTURAL SURFACE UNDER REPEATED SHEARING

The mechanical properties of the structural surface affect the stability of the engineering rock mass directly. The filling has a greater impact on the mechanical properties of the structural surface. In order to accurately analyze the effect of filling on the shear performance of structural surface,we prepared the artificial joint samples. We take the joint rock mass of the typical reservoir bank slope in the Three Gorges Reservoir area as the research object. We operate repeated shear tests on structural surfaces before and after filling,according to the filling degree 100%.The results show the following findings. (1)Based on the law of change in the shear resistance of the structural surface during the repeated shearing process,we proposes a method for repeated shearing of single specimen before and after filling. We proposes the experimental procedure and data processing method for analyze the influence of the filling on the structural surface. It can accurately analyze the influence of fillings on the shear resistance of structural surfaces. (2)The shear resistance of the structural surface deteriorates obviously after filling. The drop rate in different normal stresses is between 38.51% ~54.82%. The greater the normal stress,the greater the reduction. (3)During repeated shear,the shear strength of the filling structure surface shows a law of increasing,then decreasing,and stabilizing. It is related to the reduction of the filling material,the expose of the structural surface and the filling of the mud. The related test methods can provide a good reference for the analysis of the shear performance on the filling structure surface