Study On Evolution Mechanism Of Fracture Field Of Mining Overburden Rock In West Ⅱ District Of Tiefa Xiaoqingkuang

With China’s coal output is growing in recent years,coal and gas outburst,rock burst,a large area of the roof collapsed,water inrush and other unexpected disasters frequent power in the coal mining,especially the problem of mine water inrush,and its occurrence often caused huge losses of people’s life and property.The distribution of shape and evolution mechanism of fracture field of mining overburden rock is the main factors that affects the water inrush disaster.In this paper,the West Ⅱ district of Tiefa Xiaoqingkuang water inrush problem as the starting point,the mechanism of evolution of overburden rock fracture field of mining is depth studied.Taking mining overburden in West Ⅱ district of Tiefa Xiaoqingkuang as the main research object,took theoretical analysis,numerical simulation analysis and measurement analysis as research methods,and studied on the distribution form and evolution mechanism of fracture field of mining overburden rock.Based on the theory of elastic-plastic and fracture mechanics,combined distribution theory"O" shape,analysis on mining overburden rock fracture propagation mechanism of fracture mechanics field,according to the distribution of mining overburden rock fracture zone will be mining overburden crack field into the area of fracture water turbulent channel,the area of fracture water transitional flow channol and the area of fracture water seepage channel.Different dimensions crack field development law,evolution mechanism for the overlying rock,using with finite element(FLAC^3D)from mining overburden stress and fractured zones form a different angle to the horizontal direction in different height of crack field development morphology analysis,and it reveals the fractured field development area by a rounded rectangle shape circle to circle round transition;discrete element（UDEC）is used to study the dynamic evolution of the dynamic evolution of the mining field along the strike direction from the perspective of the movement and deformation of the overlying strata,it reveals the mechanism of dynamic development and evolution of the law of crack field of mining,and obtained the mining overburden crack field evolution angle parameters.Combined with the actual distribution of overlying strata fissures statistics of West II district,theoretical analysis and numerical simulation analysis results verify the feasibility,and from mining overburden crack distribution patterns,evolution mechanism connecting the perspective of the mining area or mining face in production safety guidance.