EMPIRICAL ESTIMATION OF SHEAR STRENGTH PARAMETERS FOR ROCK JOINTS SURROUNDING THE PROPOSED GEOLOGICAL DISPOSAL REPOSITORY IN BEISHAN,GANSU PROVINCE, CHINA

Shear strength of rock joints is an important parameter for both comparison of engineering geological conditions and stability analysis of the rock mass surrounding the pre-selected area of geological disposal repository.Based on grouping of the tonalite joints in Jiujing area,the directive statistical evaluation method was used to estimate the joint roughness coefficient(JRC).Effective length for empirical estimation of joint shear strength values was determined through the evaluation of scale dependence of JRC.Shear strength parameters along four directions of each joint group were calculated by using the JRC-JCS model.Finally,anisotropic characteristic of the rock joint shear strength was evaluated.