The Study On Laws Of Overburden Failure And Ground Movement And Deformation Of Hongling Coal Mine In Different Mining Degree

Overburden rock damage and surface movement deformation under different degree of mining in Hongling coal mine were studied through the field measurement data analysis,analog simulation experiments and numerical simulation,depended on the specific mining geological conditions of Hongling coal.According to the field data analysis of surface movement observation station of Hongling coal mine,it could be concluded that: Surface subsidence rate present a "slight-intense-mild-stability" changes along the mining degree increase of trends and tendencies;In using probability integral method for the mining surface movement deformation fully expected,expected parameters must be correct,otherwise the expected results is unreliable;The distance of turning point is affected heavily by mining also.When in the condition of highly fully mining,the turning point is in the coal wall side,and along the mining degree increase,the turning point gradually transits to the gob side and stable at last.According to the simulation experiments,it could be concluded that: The overburden rock cave mildly and step by step order when the working face promotes gradually along the strike direction;The overburden rocks move severely along the inclined direction when mining faces are caved,and if coal pillar design is not reasonable,there is the risk of rock burst;The stress balance arch plays a key role in control the strata movement.The stress balance arch gradually expands the scope of the transverse and longitudinal direction with the increase of the mining degree,and when fully mining state is reached,the stress balance arch may extend to the surface.According to the numerical simulation,it could be concluded that: When in the insufficient mining,surface subsidence rate is not increased with the increase of mining thickness,and the relationship between mining thickness is not obvious;Loose bed thickness with the maximum subsidence and horizontal movement value of the surface is inversely proportional to relationship overall.