Study on Simulation Experiment of Overburden Strata Migration Law for Backfill Mining in Steep Inclined Seam

Based on No. 845 coal mining face in Datai Mine Shaft of Muchengjian Mine as a background,the application of polystyrene foam plastics as a backfill material,with a backfill after mining method,a similar simulation experiment was conducted on a coal refuse backfill mining process in a steep inclined seam and a overburden strata migration law of the backfill mining in the steep inclined seam was studied. The study showed that during the backfill mining process in the steep inclined seam,the roof was hard to fall down,there was a roof falling zone and crack zone in the upper strata above the goaf and finally an inclined asymmetric ladder- shaped falling arch was formed. The polystyrene foam plastics blocks could be well applied to simulate bulk coal refuse block piles and could play a support and yield function. The backfill mining method with a backfill after a mining could well handle a backfill time,could effectively control the cracking expanded and stress concentrated of the roof and floor,could reduce the deformation speed and deformation value of the roof and floor,could avoid the surrounding rock outburst and could improve the mining method of the steep inclined seam.