Safety Paste Filling Mining Technology Under High-steep Slope In Pangzhihua Coal Mine

There are many mountainous areas in Guizhou province and which is also a coal production base in south China,it is common for coal mining under high-steep slopes in Guizhou province.It is of great significance to protect the ecological environment and the safety of people's lives and properties in the mining area that how to maintain the stability of the surface slope while the coal resources are extracted safely.The topographic height difference in panzhihua coal mine area is large,where north and west is higher,east and south is lower.The overlying stratum forms tabular mountain with steep slope,the average slope Angle is 36 °,maximum gradient of slope is nearly90 °,which is easy to further aggravate geological disaster after coal seam mining.In view of the above problems,this paper adopts the method of combining theoretical analysis and numerical simulation to study the main factors affecting the stability of mining-induced slope and the deformation law of mountain slope.The result of research shows that the stability of mining-induced slope is mainly affected by the development depth of ground fractures,horizontal deformation and inclined deformation of the slope,and the above three factors were affected obviously by working face mining height.Therefore,the mining height under the steep slope has the greatest influence on the slope stability.The advantages,disadvantages and the applicable conditions of the existing subsidence reduction mining technology are analyzed,the mining method of paste filling mining under high-steep slope of panzhihua coal mine is determined,and the development of mining-induced fractures and side slope fractures during paste filling mining and caving mining is analyzed by numerical simulation method,which show that paste filling mining can effectively reduce the height of fracture zone and surface deformation.Finally,the paste filling system and coal mining technology are designed,the filling capacity of the main equipment of filling mining is calculated,and the surface deformation is monitored.The monitoring results show that the paste filling mining can not only safely extract the coal resources,but also effectively reduce the surface deformation,so as to ensure the slope stability above the working face.The study of this paper has some reference and practical significance for the mining of coal seamunder mountain slope with similar geology in guizhou province.