Numerical Simulation On The Caving Of Jointed Rock Mass Roof At Different Buried Depth

It is affected seriously for the safety of mine production by the roof fall hazard of roadway and mined area. The law of gob caving which is accurately predicted is the desire of scientific and technical workers for a long time. The continuity and integrity of the rock is destroyed and the mechanical behavior of rock mass structure is seriously impacted by the presence of joints, it cannot be ignored for the complexity and randomness of the roof joints distribution, which is the factor of stability evaluation of roof fall. Therefore, it is important theoretical and practical significance for the work of the law of roof caving based on the uncertainty of jointed rock mass. Generally, the main work of paper is listed as following:(1) The law of gob roof caving, statistical distribution type of the joint occurrence and failure mechanism and research methods of jointed rock mass is generalized, and the development of Monte-Carlo simulation technique is summarized. A guideline is provided for the numerical representation of jointed rock mass roof.(2) Base on the joint network technique of Monte-Carlo, according to two-dimensional network of joint fissure by on-site exploration, characterization of jointed rock mass is achieved. The RPFA simulation of the rock mass elastic modulus and strength index is done by importing the generate grid data by ANSYS.(3) Aimed at the existing formula of critical caving span in mined area, using rock failure process analysis (RFPA), the numerical simulation is done and compared with existing theory analysis solution for the calibration procedures of RFPA. Then, based on the actual operation of a mine problem, by numerical simulation and theoretical calculation, the critical roof caving span is solved. It is useful for the actual work of the mine.(4) Base on the impact of joint of the numerical simulation method, the numerical simulation model with two different angle of jointed roof is constructed. It is calculated that the whole process of jointed roof caving for occurring separation, bending and fracture at the different depths and different conditions of joint strength. The critical jointed roof caving span and height under different conditions is obtained.