Numerical Simulation Of Surface Movement And Deformation With Land Slope And Dip Angle Of Coal Seam Changing

Coal is the important energy in China, coal industry is an important basic industry in our country.There are a series of security risks in the process of coal mining,transportation and utilization.The damage of surface subsidence caused by coal mining is particularly serious, and with a series of disastrous consequences.Such as the depletion of groundwater pollution, surface crack,road collapse ect.There are many factors that affect the surface movement and deformation caused by coal mining, this paper studies the influence of land slope and dip angle of coal seam on the surface movement and deformation caused by mining.In order to show the result of mining subsidence and show the surface movement in the space within the strata along the rock transfer rules,using numerical simulation software FLAC3 Dto build 3D model,on the basis of studying the basic theory of surface movement and the index of surface movement and deformation and referring to the geological and mining conditions of 23103 working face of a mine in Shanxi.Study the effection ofcoal seam dip angle on law of surface movement and deformation when land slope is 0?, coal seam dip angle is 0?, or 6?or 12?; Study the effection of coal surface slope on law of surface movement and deformation when coal seam dip angle is 6?,land slope is 6?, or 10?or 15?; then, analysis of the effection of land slope and coal seam dip angle on law of surface movement and deformation when coal seam dip angle and land slope are 0?or 6?or 12?.The dynamic process of surface movement and deformation is studied in 7 coal seam excavation(each time the coal excavation of 50 m), and the following conclusions are drawn:1. Effect of coal seam dip angle on law of surface movement and deformation :(1) in the second excavation(50~100m), movement and deformation began to spread to surface, and with the advancing of the working face, the influence range of the movement of the main section is gradually increasing, and the maximum sinking value is gradually increasing.(2) When the dip angle of coal seam increased(0?~12?), sinking plot of toward main section is consistent which shows multi-layer distribution symmetrical arch, the maximum subsidence is above the center of goaf; the symmetry of sinking and horizontal movement plot with tendency main section is getting worse and worse.uphill direction influence range is more than under the direction of the mountains, the maximum subsidence gradually to down shift; and maximum subsidence of the main section decreased.2. Effect of land slope on law of surface movement and deformation :When the surface slope increased(6?~15?), sinking plot of toward main sectionis consistent which shows multi- layer distribution symmetrical arch, the maximum subsidence is above the center of goaf; the symmetry of sinking and horizontal movement plot with tendency main section is getting worse and worse.The influence range of the uphill direction is more than the downhill direction, and the maximum horizontal moving value is less than the downhill direction,and maximum subsidence of the main section decreased.3. The land slope and coal seam inclination of surface movement and deformation of comprehensive effects:(1) with the dip angle of coal seam and surface slope increased, the main section of the maximum subsidence in the former three times during the excavation of the decrease trend, after three times during the excavation of the increasing trend.(2) with the dip angle of coal seam and surface slope increases, the tendency of main section nephogram and horizontal moving image symmetry more and more poor, the farther uphill migration; incline main section of the horizontal movement of the maximum value in the first three excavation has a decreasing trend in the post three times during the excavation of the increasing trend; every excavation incline main section on the level of mobile in the uphill downhill.