Study On Surface Movement And Deformation Law Of Coal Seam Mining In Loess Gully Region

Yushen mining area is the key construction area of coal resources exploitation in China.Shallow coal seam is the main part of this area and there are large-scale loess gully region on,the surface.The surface movement and deformation caused by coal seam mining under loess gully condition,s are more complex than that under conventional mining conditions..To study the law of surface movement and deformation of coal seam mining in loess gully region of Yushen mining area,and to explore the law of surface movement and deformation of coal seam mining has important guiding significance for realizing green high-yield and high-efficiency production and preventing mining damage in mining area.Taking the shallow coal seam in the loess gully region of Yushen,mining area as the research object,through collecting and analyzing the measured data of typical mines,the main factors affecting surface subsidence are determined as,follows:slope stability,bedrock thickness,loose layer thickness and mining thickness,and slope stability is the first factor;According to the characteristics of surface damage,surface cracks can be divided into th,ree types:tension compression type,sliding type and collapse type.By transforming the surface movement and deformation mode of loess gully region into the combination of slope and flat land,the superposition formula of surface subsidence value in loess gully region is given.Based on the stability of slope,the order of influence degree is obtained:slope angle>internal friction angle>slope height>cohesion>soil density,and the expression of slope safety factor is given.Taking Ningtiaota Coal Mine as the simulation object,through numerical simulation study and similar material simulation study,the slip volume and movement deformation of surface slope are compared andi analyzed,and it is concluded that downslope mining is better than reverse slope mining.Combined with the above research results,the law of surface movement and deformation of coal seam mining in loess gully region of Yushen mining area is given from three aspects:surface duration,surface rock movement parameters and slope stability,and verified by engineering examples.The research results not only provide scientific basis for prediction of surface movement and deformation of coal seam mining in loess gully region of Yushen mining area,but also provide important reference value for realizing green coal mining and comprehensive ecological improvement in Yushen mining area.