Repeated Mining Overburden Strata Movement Laws in Lower Nearly Shallow Buried Coal Seam

Using numerical simulation and theoretical analysis method,the paper focuses on the movement laws of overburden strata in the mining process of lower seam.The research shows that when the upper mining coal seam has been mined,the masonry beam structure formed after the rupturing of the single key layer is relatively stable in the mining process of lower coal seam,and the lower seam overburden does not appear the condition of stage sinking,and ground depression is relatively slow,and the dynamic upload phenomenon is not obvious compared with the shallow coal seam.