Mining-induced movement properties and fissure time-space evolution law in overlying strata

Mining-induced fracture zone will be produced in the overlying strata after the coal was mined. In this article, the mining-induced deformation of overlying strata and the time-space evolution law of fissure were studied by the methods of physical simulation and field measurement. The results show that bed separation fissure and vertical fissure will appear in the overlying strata above mining face, which form the wedge-shaped fissure zone. The open degree of fissure depends on the size of uncoordinated deformation between neighbor layers, and the absolute strata sinking controls both the width of bed separation zone and the open degree of vertical breakage fissure. At last, the calculating formula was deducted based on theoretical analysis.