SIZE EFFECT OF STRENGTH OF THE UNDERGROUND ROCK MASS BASED ON THE DISCONTINUITIES NETWORK SIMULATION FOR REDUCING ENVIRONMENTAL POLLUTION DURING MINING PROCESS

It is necessary to master the characteristics of rock mass to develop the mine safely and efficiently, and then to reduce the environmental pollution of mining. The strength parameters of rock mass are the basic problem in rock mechanics research. An important characteristic of the strength parameters of the jointed rock mass is size effect. According to the physical and mechanical significance of the representative element volume(REV) of the strength parameters of the jointed rock mass, the real rock mass discontinuities was measured by the advanced ShapeMetrix 3D photogrammetry system in tunnel of an iron mine, then the 3-D solid model of underground rock mass is established is used to obtain the geometrical distribution parameters of rock mass discontinuities. Aaccording to the geometrical distribution parameters of rock mass discontinuities, a 3D-discontinuities network model is generated based on the Monte-Carlo simulation of joint network. And then, the joint data are imported into the RFPA in order to simulate uniaxial compression test and shear test of the jointed rock mass with different sizes. The REV size of the strength parameters of the jointed rock mass is estimated to be 10mx 10m after the comprehensive numerical analysis on the compressive strength and shear strength of the jointed rock mass with different sizes, which may lay the basis for further stability evaluation of the jointed rock mass in mines. This study can provide a reliable theoretical basis for the efficient, safe and environmental protection mining of mines.