Analog Simulation Study on Deformation and Failure Laws of Overlying Strata of Full-mechanized Top-coal Caving Face with Large Mining Height in Extra Thick Coal Seam

In order to know well the movement pattern of overlying strata and the distribution of abutment pressure in the full-mechanized top-coal caving face with large mining height of the 4# coal seam of which thickness is form 14 m to 20 m,in Liuhuanggou coal mine of Xinjiang Hami Coal Industry(Group) Co.Ltd,physical simulation experiment and studies were carried out.The results showed that a stable arch structure can form in overlying strata of full-mechanized top-coal caving face with large mining height of extra thick coal seam,under the stable arch structure the fractured rock beam becomes a multi-span beam structure.The deformation and unstability of the structure in overlying strata of full-mechanized top-coal caving face with large mining height dominate the abutment pressure distribution and strata pressure behavior of coal mining face.