Study On Overlying Strata Movement Law Of Fully-mechanized Caving Mining For Thick Coal Seam In Wangjialing Coal Mine

Based on the specific geological conditions of20105working face, aiming at theproblems in the process of the Wangjialing coal mine, theoretical analysis, numericalsimulation and similar simulation test and field measurement are carried out for theroof weighting law of2#coal seam and distribution of "three zones" after mining,and obtained the following results:（1）Combined with the mechanical model of roof breaking and the experienceformula of the "three zones". The results show that the first weighting interval of mainroof is54.3m,and its periodic weighting interval is28.5m. The height of “twozones” is about111.6~173.6m.（2）Numerical simulation software, UDEC, is used to simulate the overlyingstrata movement during the mining process of20105face.The results show that thefirst weighting interval of main roof is50m,and its periodic weighting interval is25to30m. The height of destroyed cover rock is about134to146m, which is21.6to23.5times of the mining thickness, thereinto,the caving zone height is about17to20m, and fractured zone height is114to129m.The strata fracture angle in the open-offcut is63°,and it is about66°on the stop line of working face.（3）The results of simulation test show that first weighting interval of mainroof is50.4m; and its periodic weighting interval is23~34m and28.5m onaverage; the caving zone height is about16.4to19.5m, and the maximum height offractured zone is115.6m.The strata fracture angle on the open-off cut is63°,and it isabout66°on the stop line of working face.（4）Through the online monitoring system on the roof and sight instrument, roofpressure behavior of20105face and growth altitude of "three zones" are measuredand analyzed. The results of in-situ measurement coincides with those of thetheoretical calculation, numerical simulation analysis and simulation test, providingcertain theoretical support for high-yield and high-efficient mining.