Experimental Study on the Movement and Deformation of Rock Strata Between Coal Seams in the Coal Mining Above Gob Area

To guarantee safety and high productivity of the left-over coal seam mining above gob area,and considering the importance of the movement and deformation of rock strata between coal seams,we use similar simulation experiment to study the movement and deformation rules of rock strata in the same horizontal layer and vertical measuring position in the mining process.The results show that original three zones of the lower coal seam develop upwards and a controlling stratum presents duo to the mining operation of upper coal seam above gob area.Additionally,the deformed basins are formed among the rock strata,and the strata under the controlling stratum appear subsidence basin,while the strata above the controlling stratum appear fractal basin.Meanwhile,the subsidence of the strata in the same level moves asymmetrically as a whole as the working face advances.During the process of movement and deformation,the strata above the controlling stratrum move continuously,while the strata under the controlling stratum move discontinuously.