Surface subsidence law caused by fully mechanized top-coal caving in shallow-buried extra-thick coal seam

GUO Wenyan; LI Jie; MENG Haixiang; LING Chunwei

doi:10.11799/ce202508019

Abstract：Aiming at the problems of complex deformation and failure of surface caused by fully mechanized top-coal caving in shallow buried extra-thick coal seam,and lack of measured research on surface subsidence law in Xialiyuan Mining area,the research methods that combined field measurements and theoretical analysis were used in the No.40201 working face,then the surface movement destruction forms and regional spatio-temporal characteristics were analyzed,and the surface subsidence law was summarized,moreover the prediction method of surface movement and deformation in shallow buried extra-thick coal seam mining was optimized.The results show that the surface movement deformation is severe in the mining of shallow-buried extra-thick coal seam,and the surface subsidence basin forms rapidly.And the subsidence basin can be divided into the dense area of step cracks in the middle of goaf,the tensile fracture area on both sides of the boundary,and the outer continuous deformation area,and along the advancing direction of the working face,the step fracture boundary lags behind the working face about 28 m,while the tensile fracture boundary is 5.7～18.4 m ahead of the working face.The deformation is severe,the duration is short in the active period of surface movement,and the subsidence accounts for 89%～94%of the total subsidence.The zonal probability integral method can be used to predict the surface movement and deformation of shallow buried extra-thick coal seam,which has shown good applicability.