Laws of surface discontinuous deformation induced by steeply inclined coal seam mining in Majiagou Coal Mine of Tangshan

On the base of field survey results and measured data of steeply inclined coal seam mining in Majiagou Coal Mine,the distribution of discontinuous deformation of surface and development law is studied.The achievement shows that the steeply inclined coal seam mining generate surface cracks in the mine have a lot of functions.They control the division of the surface subsidence and confine the expansion of the mining induced effective owing to the distribution of the cracks in space and time.The cognition has a certain reference value for the similar conditions in steeply inclined coal seam coal mining under buildings,railways and water bodies.