THREE-DIMENSIONAL PHYSICAL SIMULATION ON OVERLYING STRATA'S MOTION RULE IN SHALLOW SEAM

Through the simulation experiment of three dimensional similar materials, the law of overburden rock breaking in the working face of the shallow buried deep thin bedrock is mastered, which provides the basis for the green mining and safe production of the shallow coal seam. The results show that shallow buried thin bedrock coal seam mining process, overburden not prone to separation, only caving zone and fractured zone, the direct roof cave with mining; surface subsidence deformation curves exhibit asymmetry, the maximum subsidence point bias in the downhill, and with the increase of coal seam inclination deformation more obviously; broken roof block along the working face of coal wall cutting, appeared in the overlying strata and the loose layer step subsidence phenomenon, surface cracks, cut and stop mining sand inrush phenomenon near the line, the surface collapse pit; the maximum appeared in the surface subsidence area of central surface subsidence, the movement of overlying strata mainly with vertical displacement, a trapezoidal integral subsidence of overlying strata; in front of the coal wall was cut down the whole fracture collapse, surface loose layer of rock caving tight synchronization occurs near the sink; coal pillar overburden out The temporary arch structure, change of overlying strata displacement near the small coal pillar, measuring point away from the coal pillar on the change of overburden large displacement; roof rock breaking arc plate can be formed relatively complete.