倾斜煤层区段煤柱变形破坏规律

Deformation and failure rule of segment coal pillar in inclined coal seam

煤层倾角是影响区段煤柱稳定性的关键因素之一.利用理论分析、相似模拟、数值模拟等方法研究了倾斜煤层开挖后倾向覆岩结构演化特征、煤柱变形及失稳破坏形式.研究结果表明,0～ 45°范围内随着煤层倾角增大,区段煤柱发生剪切失稳破坏的可能性增大;煤柱两侧覆岩结构呈现不对称分布,煤柱上侧砌体梁结构形成层位较低,煤柱下侧形成冒空区,砌体梁结构形成层位高于上侧;与水平煤层煤柱破坏以挤压变形为主不同,倾斜煤柱以沿着弱面剪切滑移破坏为主;不同倾角煤层煤柱围岩变形量呈不对称分布,煤柱下侧围岩变形量大于上侧,煤层倾角越大煤柱围岩变形量不对称分布趋势越明显.

The dip angle of a coal seam was one of the key factors affecting the stability of coal pillars. Theo- retical analysis, analog simulation and numerical calculation were employed to investigate the overlying strata structure evolution, deformation and failure of segment pillars after excavation in an inclined coal seam. The results showed that the possibility of shear failure of segment pillars increased with the increase of the coal seam dip angle in the range of 0 - 45°. The overlying strata structures on the two sides of segment pillars were asymmetrical, the voussoir beam structure was formed in a lower stratum in the upside of coal pillars, and in the downside of pillars, the vossoir beam structure was formed in an upper stratum compared with the pillar upside. The shear failure was a mail failure model in an inclined seam, different from compressional deformation in a horizontal seam. The deformation of pillar was also asymmetrical in two sides, the deformation in downside was bigger than upside, and the asymmetrical trend was in a direct proportion to the dip angle of a coal seam.