Numerical Simulation Study Of Impact Trend Of Coal And Rock System Model

Rockburst is one of the big disasters which threaten the safe manufacture of mines. Rockburst, also called coal burst, is a powerful and destructive phenomenon which will happen around roadway and workface if rock and coal destabilize sharply. When rockburst happens, the clastomeric energy of rock and coal is released suddenly and the roadway and workface are destructed catastrophically. To study the impact trend of rock and coal is an important part of the mechanism research of rockburst.By the way of systematic and complete concept, the relations of each subsystem such as the roof, coal seam, and floor are considered adequately, and the influence to the impact trend initiated by every factor and the whole effect is studied synthetically. According to the study above, the impact trend of rock and coal in the mine is revealed and judged scientifically in this paper.The theoretical analysis is conducted by the method of energy and rheological theory. On the premise of this analysis, we can say that the roof and floor have remarkable influence on the energy transmission, movement pattern, destruction, deformation and deformation velocity of the coal.The stress feature of the roof and floor strata is studied by the finite element analysis and numerical simulation, and the apparent difference between the roof and floor is found out which has the big influence to the stress and mechanical property of the coal. The sample model of the coal and rock system which can be studied easily and conveniently in the lab is established according to the different mechanic and physic features of the roof and floor. This sample model has been tested by the numerical simulation method that has the same stress states with the roof and floor on the spot.The rock and coal systematic models that have different lithological characters of the roof and floor are simulated by the RFPA (rock failure process analysis) numerical calculation software, and in the process of numerical simulation, the basic information including AE, energy, stress and failure process are acquired. After the comprehensive analysis proceeded from the factors that influence the impact trend, the changes of the impact trend of the system are studied systematically under different lithological characters of theroof and floor. The results of the study make some questions below clear:1.Every character of the impact trend of the system model will change if the strength of roof and floor changes participated by the roof and floor. The capacity of elastic deformation of the coal is enhanced significantly.2.The load-carrying capacity and the impact capacity of the model will increase nonlinearly with the increase of roof and floor strength, but the dilatancy dot stress, the accumulation capacity of the elastic energy and the energy used to destruct will decrease nonlinearly.3.The load-carrying capacity, the dilatancy dot stress and the impact capacity of the model will decrease nonlinearly when the strength of the roof and floor is increased, but the accumulation capacity of the elastic energy and the energy used to destruct will increase nonlinearly.According to the concept of systematic study, the impact trend of rock and coal system is the reflection of many physical and mechanic characters it has, and is the result of joint effect of many factors. When reflecting the process of accumulation energy and consuming energy, the systematic model of rock and coal is more effective than the single coal model. So, the system impact energy index u and the impact trend criteria are set up and they are tested and verified by the No.2 and No.4 coal seams in Suncun mine.