Study On The Movement Law Of Top Coal And Its Overlying Strata In The First Mining Face Of West Block Of Zhao Zhuang Two Well

For a long time,coal as a industrial food plays a leading role in the disposable energy consumption.In China’s existing coal resources,the proportion of thick coal seam reserves is about 45% of the proven reserves,and the proportion of output is about 40% of the total output.As the main technical means to realize high yield and high efficiency under the safe production condition of thick coal seam,the fully mechanized caving mining technology is of great significance to the study of the movement law of top coal and roof under the mining method.This paper takes the 2314 fully mechanized face of Zhao Zhuang two as the research object,based on the theoretical analysis,the numerical simulation,the physical experiment and the field measurement as the technical means to study the stress distribution of the coal and rock mass in front of the work,the breaking and migration law of top coal and its overlying rock and the law of the ore pressure.The main results are as follows:(1)the physical and mechanical parameters of the top and floor of the 2314 working face are obtained by field investigation,physical and mechanical experiments combined with the peep of top plate boreholes,which lays a foundation for the subsequent numerical calculation and field measurement.(2)through numerical simulation,in the process of fully mechanized caving mining,the stress rises in front of the working face,and the middle of the working face falls ahead of the top and lower part of the working face.Under the condition of different working face length,the distribution of vertical stress is the same.It is symmetrical on the middle of the working face,the greater the length of the working face,the increase of the plastic zone,the larger the fall height,and the relative larger bearing pressure in the end of the end.The peak pressure peak in front of the working face becomes larger,the distance from the peak point to the working face becomes larger,the influence range of the forward support pressure becomes larger,and the stress concentration in front of the working face is aggravated.The cyclic pressure and roof caving height of the working face are basically consistent with the measured ones.(3)the field measurement shows that the displacement and deformation of the old top are affected by the displacement and deformation of the old top,and the deformation of the old roof is affected by the displacement and deformation of the old roof.The displacement and deformation of the measured points in the direct top and the top coal are finally displaced,and the displacement and deformation of the measured points in the old roof are the largest in the period of the observation period.In the normal recovery stage,the displacement and deformation of top coal and overlying rock are larger than that of subsided columns.