Abstract:

According to 845 workface in Datai of Muchengjian coal mine, this paper makes the similar simulation test of backfill mining in steep coal seam by gangue using polyethylene plastic foam board as backfill and taking the backfilling while mining in steep coal seam. It research on the overburden migration rule in the process of backfill mining in steep coal seam. It indicates that: rock stratum above the gob have two-zones (caving zone and fissure zone) in the process of backfill mining in steep coal seam, the caving of roof is not easy, eventually it forms the trapezoidal caving arch which is tilted and asymmetric; The blocks of polyethylene plastic foam can simulate the stacking of the loose gangue to support and yield for surrounding rock; The style of backfilling while mining can grasp the filling time to control the crack propagation and stress concentration of the roof and floor to avoid the burst of surrounding rock and given the test evidence to backfill mining in coal mine, it has perfected the mining method of the steep coal seam.

Key words: steep coal seam, backfill mining, overburden migration, similar simulation, gangue, polyethylene plastics