Research on Prediction of Instability Failure for Gassy Coal Sample in Different Confining Pressure Based on Microseism

According to the rock failure damage theories and the gas-solid coupling method, used RFPA2D-GasFlow soft code to study the characteristics of microseism in time and space for gassy coal sample in different confining pressure. It is shown that there is some microseism precursory before main shock. Basing on the characteristics of microseism precursory events amount in time can be warned in advance, and basing on the characteristics of microseism precursory events produced by tension stress in space,there is can divide potential failure danger zone. It is shown that the divided results for potential failure danger zone are exactly, and with the increment of confining pressure, the accuracy of divided results on potential failure danger zone become higher. It is found that the potential failure danger zone consistent with crack initiatory zone by contrasted potential failure danger zone to crack development process, and with the increment of confining pressure, the consistency become higher.