节理表面粗糙度演化的试验研究.docVIP

 Experimental study on asperity evolution of joint surfaces# FAN Xiang, CAO Ping, JIN Jin** (School of Resources and Safety Engineering, Central South University, Changsha 410083, 5 10 15 20 25 30 35 40 China) Abstract: Laboratory cyclic shear tests were conducted to investigate the asperity evolution of joint surfaces. There were five samples and each sample had been sheared for three times under different normal stresses. Prior to and after each test, the roughness of each specimen was characterized by measuring the surface morphology using a 3D non-contact high-accuracy laser topography instrument (the Talysurf CLI 2000). Nine parameters, used to characterize the morphologic features of joint surfaces, were worked out after each scanning test. With analysing the experimental results, the variations of morphologic features under cyclic shear loading, were found out. In the shear tests under different normal stresses, maximum height, arithmetical mean height and root mean square height of the joint surface had downward tendencies; Skewness, kurtosis and root mean square gradient of the joint surface had no obvious changes and the shape of joint profiles were hardly influenced by shear tests. Developed interfacial area ratio of the joint surface had a down trend and the complexity degree went down. There was a growth in the texture aspect ratio of the joint surface. The anisotropic property of the surface varied little and the surfaces kept anisotropic. Key words: joint shear tests; morphology of surface; characteristic patameters; asperity evolution 0 Introduction A joint is composed of two rough surfaces that relatively contact with each other. Many researchers have recognized that the morphology of natural rock joint surfaces has a significant influence on the mechanical and hydraulic characteristics of a joint. Most researches have adopted the indoor experiment methods to study the surface morphology and mechanical properties of joints [1-2]. In these test