Effect of Infill Moisture Content and Thickness on Shear Behavior of Rough Rock Joints

摘要

The shear behavior of rock joints have normally been investigated inthe past by conducting conventional direct shear test in the laboratory,where during the shearing process, the effect of infill material is oftenneglected. It is well known that the shear strength of rock jointsdecreases significantly due to the presence of gauge on infill materials.In addition, the joint strength is highly dependent on the wear behaviorof joint asperity during shear movement. Though many researcheshave been done about the influence of asperity on joint shear strength,however, only a limited number of studies are found in relation to theinfluences of infill thickness and water content on the shear strength ofinfilled rough joints. The current study is an attempt to investigate theshear behavior of soft rough joints under Constant Normal Load(CNL)conditions, with special reference to the influences of infill thicknessand moisture content and wear behavior of joint asperity. The resultsof this study show that infill water content may influence shearstrength of rough rock joints, as significantly as infill thickness.