A two-dimensional numerical mine strata in the vicinity of seam 349 in model of a large （1 000 m× 200 m） section of Iongwall panel 802 in part B of the Murcki Colliery in the Upper Silesian Coal Basin, Poland, ...A two-dimensional numerical mine strata in the vicinity of seam 349 in model of a large （1 000 m× 200 m） section of Iongwall panel 802 in part B of the Murcki Colliery in the Upper Silesian Coal Basin, Poland, was built using the Universal Distinct Element Code UDEC. Longwall extraction of seam 349 with roof caving was simulated in the model over a length of 450 m. Mining-induced changes in displacements, strains and stresses in the mine strata were investigated. Under the assumptions that （1） methane-bearing strata occur 15.6 m beneath seam 349 and include seam 350 and the strata lying beneath, and （2） the methane reservoir pressure is equal to 2 MPa, a fully coupled mechanical hydraulic analysis was performed in which joint conductivity was dependent on the mechanical deformation and, conversely, the mechanical behavior of rock masses was affected by joint fluid pressure. It was shown that migration of methane from coal seams lying beneath the mined seam is possible under conditions where the floor strata deform to a great extent, undergo separation, fracture and break into blocks.展开更多
文摘A two-dimensional numerical mine strata in the vicinity of seam 349 in model of a large （1 000 m× 200 m） section of Iongwall panel 802 in part B of the Murcki Colliery in the Upper Silesian Coal Basin, Poland, was built using the Universal Distinct Element Code UDEC. Longwall extraction of seam 349 with roof caving was simulated in the model over a length of 450 m. Mining-induced changes in displacements, strains and stresses in the mine strata were investigated. Under the assumptions that （1） methane-bearing strata occur 15.6 m beneath seam 349 and include seam 350 and the strata lying beneath, and （2） the methane reservoir pressure is equal to 2 MPa, a fully coupled mechanical hydraulic analysis was performed in which joint conductivity was dependent on the mechanical deformation and, conversely, the mechanical behavior of rock masses was affected by joint fluid pressure. It was shown that migration of methane from coal seams lying beneath the mined seam is possible under conditions where the floor strata deform to a great extent, undergo separation, fracture and break into blocks.
