倾斜煤层动压巷道围岩应力分布规律的数值分析

Numerical Analysis of the Stress in the Surrounding Rock of the Dynamic Pressure Tunnel with Inclined Seams

针对倾斜煤层巷道围岩应力分布规律问题,建立了不同岩层倾角的数值计算模型,计算分析了倾斜煤层在动压作用下的围岩应力变化过程。通过对计算结果的分析,得知在岩层倾角为30°～40°时,围岩集中应力区域向两帮顶角区域转移;50°～60°时,向下帮底角区域转移;70°～80°时,转移至下帮顶角区域;同时由40°开始,围岩开始显现较强的不对称性,并随岩层倾角的增大快速增大。在动压作用下,围岩不同位置处的应力随动压的增大近似同比例增大;当岩层倾角在10°～50°时,应力提高率处于0.5～2.3;50°～80°时,基本处于0.5左右。针对围岩应力分布的不对称系数分析得知,岩层倾角越大,不对称系数越大;在岩层倾角为30°～80°时,不对称系数在动压作用下基本保持不变,说明在动压作用下围岩应力会持续处于不对称状态。

In view of the problem of the stress of the surrounding rock in the tunnel with inclined seam, the numerical model for different inclined angle was established. The stress of surrounding rock under action of ground pressure in the inclined seam was calculated. It was concluded that the concentrate stress was shift to the up corner angle while the angle of seam was between 30° and 40°. And the concentrate stress was shift to the down corner angle while the angle of seam was between 50° and 60° ,and it was shift to the up corner of the down part. While the angle of seam was larger than 40° ,the asymmetry was clearly and it becomes larger when the angle is larger. The stress of surround rock enlarged linear with the angle. When the angle was between the 10° and 50° ,the enlarged factor was between 0. 5 and 2. 3. When the angle was between 50° and 80°, the factor was about 0. 5. To the factor of asymmetry,it was larger when the angle was bigger. When the angle was between 30° and 80° ,the factor of asymmetry was about constant and it can be concluded that the stress of surround rock was in the situation of asymmetry under the dynamic pressure.