(1. Coal Mining and Designing Department,Tiandi Science and Technology Co.,Ltd,Beijing 100013,China; 2. Beijing Mining Research Institute,China Coal Research Institute,Beijing 100013,China;3. State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400030,China)
Abstract:Based on the triaxial stress thermal-hydro-mechanical coal containing gas system,unloading confining pressure experiments under different gas pressures and confining pressuresand speeds of unloading confining pressures,are carried out to study the influences of gas pressure,stress,speed of unloading confining pressure and their coupling conditions on the mechanical properties and the laws of roadway surrounding rock deformation and failure. The results show that:(1) The gas pressure has an obvious infulence on the coal elasticity modulus. The elasticity modulus decreases with the increase of gas pressure. (2) The confining pressure has an obvious infulence on the coal elasticity modulus. The elasticity modulus increases with the increase of confining pressure. (3) The speed of unloading confining pressure has an obvious infulence on the coal elasticity modulus. The elasticity modulus decreases with the increase of the speed of unloading confining pressure. (4) The time before deformation and failure increases with increase of confining pressure,decrease of gas pressure and the increase of speed of unloading confining pressure.
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