To accurately predict coal burst hazards and estimate the failure of coal pillars in underground coal mining systems,it is of great significance to understand the mechanical behavior of coal-rock bimaterial composite ...To accurately predict coal burst hazards and estimate the failure of coal pillars in underground coal mining systems,it is of great significance to understand the mechanical behavior of coal-rock bimaterial composite structures.This paper presents experimental and numerical investigations on the response of rock-coal,coal-rock,and rock-coal-rock bimaterial composite structures under triaxial compression.The triaxial compression experiments are conducted under confining pressures in the range of 0-20 MPa.The resulting inside fracture networks are detected using X-ray-based computed tomography(CT).The experimentally observed data indicate that the mechanical parameters of the rock-coalrock composites are superior to those of the rock-coal and coal-rock combinations.After compression failure,the coal-rock combination specimens are analyzed via X-ray CT.The results display that the failure of the coal-rock composite bodies primarily takes place within the coal.Further,the bursting proneness is reduced by increasing confining pressure.Subsequently,the corresponding numerical simulations of the experiments are carried out by using the particle flow code.The numerical results reveal that coal is vulnerable with regard to energy storage and accumulation.展开更多
基金This study was financially supported by Beijing Outstanding Young Scientist Program(BJJWZYJH01201911413037)National Natural Science Foundation of China(41877257+3 种基金5162240452009131)Shaanxi Coal Group Key Project(2018SMHKJ-A-J-03)Yueqi outstanding scholar Award Program by CUMTB。
文摘To accurately predict coal burst hazards and estimate the failure of coal pillars in underground coal mining systems,it is of great significance to understand the mechanical behavior of coal-rock bimaterial composite structures.This paper presents experimental and numerical investigations on the response of rock-coal,coal-rock,and rock-coal-rock bimaterial composite structures under triaxial compression.The triaxial compression experiments are conducted under confining pressures in the range of 0-20 MPa.The resulting inside fracture networks are detected using X-ray-based computed tomography(CT).The experimentally observed data indicate that the mechanical parameters of the rock-coalrock composites are superior to those of the rock-coal and coal-rock combinations.After compression failure,the coal-rock combination specimens are analyzed via X-ray CT.The results display that the failure of the coal-rock composite bodies primarily takes place within the coal.Further,the bursting proneness is reduced by increasing confining pressure.Subsequently,the corresponding numerical simulations of the experiments are carried out by using the particle flow code.The numerical results reveal that coal is vulnerable with regard to energy storage and accumulation.
