Simulation study on energy evolution and release of surrounding rock in stope

The strain energy of rock mass is a comprehensive physical quantity that integrates principal stress，elastic modulus and Poisson′s ratio，which can better explain the dynamic phenomena in mining process.In order to reveal the energy evolution process and release law of stope surrounding rock during mining process，a calculation method of energy evolution and releasing is derived based on rock mass strain energy theory.A numerical calculation model is established with No.3 of the Pingshuo Coal Mine as engineering background and the energy change of surrounding rock of the stope at different mining times were simulated.The results show：① The peak strain energy of the surrounding rock gradually moves forward as the working face advances，and the peak of coal seam energy is mainly concentrated within 8 m in front of the coal wall； The strain energy of the coal seam is relatively high，and the energy value in the hard rock layers of the top and bottom is relatively low；② After excavation，the energy release zone is above cut-eye，and the energy accumulation zone is in front and behind the cut-eye； In terms of local quality conditions，when the working face is in normal mining condition，the main energy release zone is within 8 m above the coal wall of the working face，the main accumulation zone of energy is within 2～8 m in front of the coal wall.Therefore，it is necessary to support the coal wall timely to prevent the roof falling caused by the rapid release of its energy，and to take measures to control the stress concentration in front of the coal wall with the tendency of dynamic disasters.