煤柱宽度对综放回采巷道围岩破坏场影响分析

Influenced of coal pillar width on deformation and fracture of gateway surrounding rocks in fully mechanized top-coal caving mining

为了研究综放回采巷道围岩破坏场随护巷煤柱宽度变化的特征,采用计算机数值模拟(FLAC3D)对不同煤柱宽度综放回采巷道围岩破坏进行了研究。结果表明:不同宽度煤柱的巷道围岩在回采期间破坏有很大差异,极窄小煤柱完全破坏,中等煤柱压应力较高,较大宽度煤柱内存在弹性区,但造成的煤炭损失大;巷帮实煤体的破坏主要以剪切破坏为主,而煤柱的破坏则主要是剪切、拉伸复合破坏。合理的护巷煤柱宽度应大于保证煤柱不被压垮、不发生裂隙向采空区漏风、诱发自燃的最小煤柱尺寸,同时最大煤柱宽度应避免煤柱承受较高应力而失去稳定性。

In order to study the deformation and fracture characteristics of gateway surrounding rocks influenced by coal pillar width in fully mechanized top-coal caving （FMTC）, the deformation and fracture are studied with different coal pillar widths by numerical simulation. The results show that the deformation and fracture of gateway surrounding rocks and pillars are diverse with different coal pillar widths during caving. Small widths are integrated deformation and fracture, middle widths support high pressure and wider present elastical area in coal pillar but the coal loss is more than other widths. The kind of coal entity fracture beside gateway is main cut, but pillar is mainly composite fracture of cut and pull-extend. The appropriate coal pillar width is more than the pillar that is preserved to be not collapsed, leaked and self-ignited but the max pillar avoids bearing more stress thus having less stability.