深井厚煤层沿空巷道掘采全过程应力分布及支护技术

Stress distribution and support technology in the whole process of gob-side entry driving and mining in deep thick coal seam

为解决反复加卸载作用下深井厚煤层沿空巷道围岩控制难题,以袁店一井煤矿1037工作面回风巷为工程背景,通过FLAC3D数值模拟,对反复加卸载沿空巷道全过程应力分布特征及演化规律进行了系统研究,提出了“锚带网索+帮部喷注浆+顶板非对称锚索梁补强+煤柱肩底角锚索梁补强”联合支护方案。研究结果表明:(1)上工作面采空区侧向支承压力峰值距煤壁12~13 m,其值约27.5 MPa,影响范围为60~70 m;(2)1037工作面风巷掘进后,垂直应力峰值向实体煤深部转移,距采空区煤壁约17 m处,约30.7 MPa,相比掘巷前,增大11.6%,小煤柱上垂直应力相比掘巷前,降低了约62.6%;(3)随着1037工作面的推进,工作面前方20 m处形成超前支承压力峰值,达到45.9 MPa,约为2.8倍原岩应力。现场观测结果表明,控制方案取得较好控制效果。

In order to solve the problem of surrounding rock control of gob-side roadway in deep and thick coal seam under repeated loading and unloading,the return airway of No.1037 Face of Yuandian Yijing Mine was taken as the engineering background,the whole process stress distribution characteristics and evolution law of gob-side roadway under repeated loading and unloading were systematically studied by FLAC3D numerical simulation.The combined support scheme of"anchor belt net cable+spray grouting on the side+reinforcement of asymmetric anchor beam in roof+anchor beam reinforcement at the bottom angle of coal pillar shoulder"was put forward.The results showed that:①The peak value of lateral abutment pressure in goaf at the upper working face was 12~13m away from the coal wall,which is about 27.5MPa.The influence range was 60~70m.②After excavation of air roadway at No.1037 Face,the vertical stress peak shifted to the deep of solid coal,about 17m away from the coal wall of goaf,about 30.7MPa,which increased by 11.6%compared with that before excavation,and the vertical stress on small coal pillar decreased by about 62.6%compared with that before excavation.③When No.1037 face was advanced,the peak abutment pressure reached 45.9MPa 20m ahead of the working face,which was about 2.8 times the stress of the original rock.Field observation results showed that the control scheme achieved a better control effect.