Simulation analysis of strata movement characteristics of backfill-strip mining

For the problems of high backfill cost and the shortage of backfill material, a new concept of solid backfill-strip mining method is proposed on the basis of the three-step mining subsidence control, which combines the advantages of strip mining and back?lling mining. Through this mining technology, interval backfill mining is firstly conducted, then residual coal pillar is recycled, and eventually coupled body of the backfill materials and partition coal pillars are formed to support the overburden strata and achieve the goal of subsidence control. In this paper, the feasibility and principle of backfill-strip mining technology is presented firstly, then numerical simulation is applied to study strata movement characteristics in the backfill strip mining. Through numerical simulation method, the influence factors of surface subsidence control are analyzed specifically from several aspects including the size of partition coal pillars, the caving mining working faces and backfill mining working faces, and strata movement characteristics in different mining methods are compared and analyzed, including backfill-strip mining. The study can provides scientific technical reference for the safe mining engineering design and surface disaster protection for backfill-strip mining.