沿空留巷围岩受力变形特征及其支护优化设计

Characteristics of stress and deformation of surrounding rock in gob-side entry retaining and the optimized support design

针对高河煤矿W1309工作面沿空留巷煤炭开采率低、井下矿灾易发等工程问题,分析柔模支护下沿空留巷的围岩稳定性问题与变形破坏特征,建立力学悬臂梁结构模型,对比软弱顶板和厚硬顶板对沿空留巷覆岩应力分布区的影响,呈现不同类型的应力分布区。并利用FLAC3D软件对采动影响下沿空巷道围岩应力及变形特征进行计算,发现煤帮变形量与变形幅度均大于柔模帮相应值。通过理论分析与数值计算,提出采用非均称支护设计理念的巷道支护优化方案。

In order to solve the engineering problems such as low mining coefficient and frequent mining disasters in W1309 coal face using the gob-side entry retaining technology, the stability problems and deformation-failure characteristics of surrounding rock in gob-side entry retaining under the flexible formwork support were analyzed. The mechanical model of cantilever beam structure was established,and the influence of soft-weak roof and thick-hard roof on the stress distribution area of overlying strata in gob-side entry retaining was compared,and different types of stress distribution areas were presented finally. FLAC3 Dwas applied to calculate the stress and deformation characteristics of the surrounding rock of the gob-side entry under the mining influence,and we found that,the deformation and deformation amplitude of coal side are all greater than the corresponding values of the flexible formwork side. Through theoretical analysis and numerical calculation, the optimization scheme of roadway support with non-uniform support design philosophy was finally proposed.