深埋大采高沿空留巷柔模砼墙宽度优化研究OA

To address the problem of determining the appropriate width of flexible formwork wall in gob-side entry retaining under deep and large mining height conditions,the gob-side entry retaining of the 20203 working face at Dahaize Coal Mine was taken as the engineering background.A combined approach integrating theoretical analysis,numerical simulation,and engineering verification was adopted.A mechanical model of gob-side entry retaining with a flexible formwork concrete wall was established,and UDEC numerical simulations were conducted to reveal the evolution characteristics of surrounding rock deformation and stress under different wall widths(1.0 m,1.2 m,1.5 m,and 1.7 m).The results indicate that,with increasing wall width,surrounding rock deformation and stress concentration are significantly reduced,exhibiting a clear marginal effect.When the wall width increases from 1.0 m to 1.5 m,the maximum roof subsidence decreases by 21.05%,and the stability of the surrounding rock is markedly improved;when the width is further increased to 1.7 m,the improvement becomes noticeably less pronounced.Based on engineering parameter verification,the reasonable wall width is determined to be 1.5 m.Under this condition,the bearing capacity of the wall is 18 925.2 kN/m with a safety factor of 1.73,satisfying the safety and economic requirements of gob-side entry retaining under deep and large mining height conditions.