Effect of joint inclination angles on the earth pressure against the support system in a jointed rock mass

Abstract

This study investigated the magnitude and distribution of the earth pressure on the support system in a jointed rock mass, due to the different joint inclination angles, joint shear conditions, and rock types. The study mainly focused on the sensitivity of the joint inclination angles on the earth pressure. Based on a physical model test (Son and Park, 2014), extended numerical parametric studies were conducted considering rock-structure interactions based on the discrete element method, which can consider the rock and joint characteristics of rock mass. The results of numerical tests were compared with an analytical method based on a wedge theory. The comparison showed that the earth pressure was highly influenced by the joint inclination angles, together with different rock types. The study indicated that the effect of joint inclination angle was particularly more significant when a rock type was harder and a joint was under the condition of joint sliding. The test results were also compared with Peck’s earth pressure, which has been frequently used for soil ground. The comparison showed that the earth pressure in a jointed rock mass can be significantly different from that in soil ground depending on the joint inclination angles and rock types.