Mathematical Model And The Law Of Water Resisting Property In Partial Backfill Mining Of Shallow Seam

Water conversation mining is a important issue for sustainable development of coal and special water conversation mining is currently the technical and key problems of the mining sector in shallow seam. Using a partial backfill mining is an effective way to protect the roof of water resisting layer the special water preserved shallow seam mining. It is important to research and the establishment of mathematical models of water resisting layer in the local filling cracks in shallow seam,for determining a reasonable filling parameters guide the mining practice of partial filling is very important theoretical and practical significance.With the base of the tutor's project of study abroad repatriate person of ministry of educa- tion, according to special water conversation mining of classification the roof, by simulating model test in the basic of simulating different filling materials, it is conclude law of mined water resisting property, comparative analysis of "high" and "low" fill material the law of water resisting layer under the conditions of the stability the longwall 250m, and other space filling two bands,it found that a reasonable interval between filling and filling the width of the width of a direct impact on the development of a high degree "upward crack" and " downward crack ", and ultimately affect the stability of impermeable layer.Based on physical similar simulation, it proposed mathematical model of stability water resisting layer partial backfill mining in shallow seam, it determined the formula height of upward cracks and subsidence impermeable layer. It Reached a high degree of upward cracks is correlation to and filling the width of a positive interval, the height of downward crack is mainly determined to maximum subsidence of water resisting layer, maximum subsidence of water resisting layer is composed of subsidence of filling material above the supporting pillar of the subsidence bedrock confining layer. Among them, the subsidence of filling is positive related to ratio of filling width and filling the width of the interval,in the ratio of filling width and filling the width of the interval, the subsidence of filling is positive related to the corner with the rock collapse,above the support pillar and the influencing factors relations with the filling of the compression is similar to the amount of bedrock sinking impermeable layer impermeable layer and the bedrock negative correlation, with the filling width decreases, the impermeable layer of bedrock subsidence curves similar to the hyperbolic shape upward.It is showed that the result of mathmatics of water resisting layer is equal to physical similar simulation,which provid scientific theoretical basis for partial backfill in shallow seam.