Analysis And Evaluation Of Coal Seam Mining Surface Subsidence Disaster In Loess Gully Region Of Yushenfu

The coal seam of Yushenfu mining area is a typical shallow coal seam.The mining thickness of the coal seam in this area is large,and it is easy to produce serious cracks on the surface after the coal seam mining.So when the coal seam is mined in the loess gully region of shallow coal seam,the surface subsidence disaster becomes more serious.Therefore,the paper analyzes and evaluates the surface subs.idence disaster of coal seam mining in loess gully region of Yushenfu.It is very important to realize the safe mining and subsidence disaster prevention in the loess gully region and similar mining geology.This paper takes the typical mine in loess gully region of Yushenfu as the research object.On the basis of summarizing the surface subsidence law of typical mine coal seams,the characteristics and classification of surface cracks of coal seam mining in loess gully region of Yushenfu are given.The main factors affecting the mining subsidence in the loess gully region of Yushenfu are obtained by combining the analysis of the surface and rock stratum movement parameters of coal seam mining in typical coal mines:the ratio of bedrock thickness to mining height(JC),the ratio of bedrock thickness to the thickness of the loose layer(JZ),and the slope stability(G).Through the similar material simulation experiment,the characteristics of overburden failure and the law of surface subsidence were analyzed by combining with,Jc,Jz,and G.The subsidence coefficient of upper and lower coal seams is 0.61 and,0.71 respectively,and the repeated mining coefficient is 1.16.When the upper and lower working face is arranged in the alternate distance,the surface subsidence and overburden damage can be effectively reduced.The location,width and fracture mechanism of ground crack in coal seam mining in loess gully region of Yushenfu were analyzed and studied,and a method for evaluating the surface subsidence of coal seam in loess gully region is given.Finally,the reliability of the evaluation method is verified by engineering examples.The research results provide a theoretical basis for the prevention and evaluation of surface subsidence disaster after coal mining in the loess gully region of Yushenfu and similar mining geological conditions.