ANISOTROPY EVALUATION OF ROCK JOINT ROUGHNESS USING ROTATION SAMPLING METHOD

Uncertainty exists in evaluation for anisotropy of a rock joint roughness. One can obtain different anisotropy evaluation of rock joint roughness via different methods even for the same sample, which makes anisotropy evaluation results inconsistent. To this end, this paper proposed a rotation sampling method to evaluate the anisotropy of rock joint roughness coefficient(JRC). The method uses the 3D point cloud data of a rock joint sample that obtained from high-precision 3D laser scanning technology. Based on the comparison analysis of a typical rock joint sample, the influences of the sampling method and the sampling size on the anisotropy evaluation results of JRC were investigated. The results show that the existing single profile sampling method makes the JRC anisotropy data discrete and therefore requires larger sampling size to improve its accuracy of the obtained JRC data. The proposed rotation sampling method can overcome this problem of JRC anisotropy data dispersion and obtain accurate and reliable JRC data for anisotropy evaluation. The method and the results can provide a reference for further studying the anisotropy of rock joint roughness.