Experimental study of the effect of depth on mechanical parameters of rock

Abstract

Study on the effect of depth on physical and mechanical parameters of rock plays an important role in understanding the deformation and failure of rock at depth and analyzing the mechanism of engineering disasters at depth. In this work, basalt specimen are taken from at 7 different depths ranging from 410 m to 1010 m at Datai Coal Mine, Beijing, which are processed into 77 standard rock samples (21 for uniaxial compression tests, 35 for conventional triaxial compression tests, 21 for Brazilian tests). With the rock mechanics test system of MTS815 and RMTS150, some physical and mechanical parameters are obtained, including rock density, uniaxial compressive strength, uniaxial tensile strength, elastic modulus, Poisson’s ratio, cohesion, friction angle, by uniaxial compression tests, conventional triaxial tests and Brazilian tests. The results show that, rock density, uniaxial compressive strength, uniaxial tensile strength, elastic modulus, cohesion and friction angle increase linearly with increasing depth, and there is a linear decreasing in Poisson’s ratio with increasing depth. Furthermore, the cause of the difference of physical and mechanical parameters of the same rock at different depth is analyzed.