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直角梯形巷道围岩应力非对称特征数值模拟研究

Numerical simulation study on asymmetric characteristics of surrounding rock stress in right angle trapezoidal roadway

  • 摘要: 针对石炭井二矿区倾斜煤层直角梯形巷道围岩出现非对称变形破坏,给巷道的稳定性控制和支护带来很大困难的问题,采用数值模拟方法,对该矿区巷道垂直应力、水平应力及水平位移进行了系统分析研究,给出了倾斜煤层直角梯形巷道围岩应力的分布规律及破坏特征。研究结果表明:巷道两帮、顶板及尖角处均呈现明显的非对称应力集中现象,主要表现为两帮应力集中峰值和距帮部侧壁的距离差异明显,并随着倾角和地应力增大而增大,当倾角为18°~27°,低帮应力集中峰值为高帮的1.07~1.33 倍,高帮到巷道帮部侧壁的距离比低帮大1.26~3.79 m。其次沿煤层倾角相同方向对称的两尖角处表现为明显的压应力区,而相反方向两尖角处则表现为明显的拉应力区,且压应力和拉应力的最大值均出现在巷道顶板的两尖角处,其破坏特征表现为低帮一侧及底板严重的变形破坏。

     

    Abstract: The asymmetric deformation and failure of surrounding rock of right angle trapezoidal roadway in the inclined coal seam of Shitanjing No.2 Mine resulted in much difficulty to the stability control and support of the roadway. Based on this, the numerical simulation method was adopted to make a systematic analysis of the vertical stress, the horizontal stress and the horizontal displacement of roadways and the distribution and failure characteristics of surrounding inclined coal seam right angle trapezoidal roadway were given. The results show that there are obvious asymmetric stress concentration phenomena in the two sides, roof and sharp corners of the roadway which features a sharp differences between the stress concentration peak distances of two sides and the distances from the sidewalls;the stress grows as the inclination and ground stress increase when the inclination angle is 18° to 27°, the peak stress concentration of the low side is 1.07 to 1.33 times higher than that of the high side and the distance from the high side to the side wall of the roadway side is 1.26 to 3.79 m higher than the distance from the low side. Next, the two symmetrical sharp corners along the same direction of the coal seam are characterized by obvious compressive stress zones; by contrast, the two sharp corners in the opposite direction show obvious tensile stress. The maximum values of compressive stress and tensile stress appear at the two sharp corners of the roof of the roadway and its failures are characterized by severe deformation and damage on the low side and the floor plate.

     

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