Numerical simulation of abutment pressure in coal for non-pillar mining

Abstract：Based on the theory that mining of coal seam causes wide range of overlying stratum’s movement and stress redistribution,especially the change of abutment pressure of coal around mining face by using ANSYS to simulate non-pillar mining,observeing that there is crack in three principal stress directions of the coal above the goaf in the process of mining and the crack develops along the working direction of the mining face,thus preliminaryly got the distribution and development situation of cracks in the coal above the goaf under the influence of mining.According to the numerical simulation results,figured out the stress environment curves of coal around the working face,namely the reduced pressure zone,pressure area and voltage stabilizing area.Through calculating,the range of abutment pressure concentration coefficient for non-pillar mining is 2.54~2.96.Meanwhile,through the relation between the width of small coal pillar and the stress concentration coefficient,it is found that under the same conditions,the greater the wide column is,the smaller the coefficient is,and the smaller the increment is.