Research On The Influence Of Gently Sloping Coal Seam Mining On Slope Deformation And Stability In Mountainous Areas

In recent years,the rich coal resources in the west of China have become the focus of development.The mining scale of gently inclined coal seam in the western mountainous area is expanding day by day.The mining leads to the instability of the mountainous slope,causing a series of geological disasters such as landslide and collapse,which poses a huge threat to the life safety of the people in the mining area and the development of the local economy.The field investigation shows that the slope deformation and failure caused by the mining of gently inclined coal seam in mountainous area are controlled by the overlying condition of coal seam,the mining mode of coal seam,the relative position of working face and slope and other factors.Different influencing factors will have different influences on the deformation and stability of mining slope.Through the impact on the mining slope deformation and stability of the study,can be summarized mining slope deformation law,understand the mining failure mechanism and the factors affecting the stability of the slope instability,provide a reference for similar mining area well versed in mining way,for the local economic development and environmental protection to find a balance,to reduce the mine geology disaster,The purpose of protecting the safety of life and property of people in mining areas.In this paper,the displacement,stress-strain characteristics and stability of the mining slope under the mining condition of gently inclined coal seam are calculated,and the influence of different influencing factors on the deformation characteristics and stability of the mining slope is analyzed and studied.Firstly,the stress distribution characteristics and deformation characteristics of overburden rock and slope of mining-induced slope in mining-induced goaf under the mining condition of gently inclined coal seam are summarized and analyzed.On the basis of the above analysis,the mining-induced slope near Baijiagou in mining area is selected as the research object.Midas/GTS NX finite element numerical simulation software was used to establish a threedimensional numerical model in combination with the geological conditions of the study area and the mining conditions of the coal seam.The study was carried out by combining numerical simulation and theoretical analysis.Finally,the Baijiagou area is taken as the prototype by changing the overlying condition of coal seam,the mining position of working face and the mining method of coal seam,and several three-dimensional models are established to simulate the displacement and stress-strain changes of the slope,calculate the stability of the mininginduced slope,and summarize the influence of different factors on the deformation characteristics and stability of the mining-induced slope.The results show that:(1)In addition to different coal seam occurrence conditions and other conditions of the same state,the down-dip coal seam mining is not conducive to the stability of mountain slope,the greater the inclination,the worse the stability,the reverse dip coal seam mining is conducive to the stability of mountain slope,the greater the inclination,the better the stability,the horizontal coal seam stability between the two.(2)The mining position of working face will affect the failure type and stability of mininginduced slope in mountainous area.In mountainous areas,when the working face is behind one side of the slope,the influence on both sides of the slope is small and the slope stability is better.When the mining slope is arranged under one slope and in the middle of the valley,the stability of the mining slope is poor and it is easy to be destabilized and slide failure occurs.The difference is that the failure type of the former is push-slide landslide,while the failure type of the latter is traction landslide,and affected by rainfall,the failure degree of push-slide landslide is often more serious than that of traction landslide.(3)Compared with the initial mining,the area affected by repeated mining on the slope surface increases,the surface subsidence increases,the shear failure at the foot of the slope intensizes,and the stability of the mining-induced slope decreases,which is not conducive to the stability of the mining-induced slope.