高瓦斯多巷系统回采巷道布置方法研究

为了解决高瓦斯煤层两进两回通风方法中外圈巷道维护困难的问题，综合应用理论分析、数值模拟和现场实测等方法研究分析了：① 巷道群及煤柱在掘巷、一侧采动、两侧采动后围岩应力演化规律和巷道变形特征；② 煤柱宽度对巷道围岩稳定的影响规律。揭示了在两侧采动条件下、煤柱内巷道及煤柱本身变形稳定机理，提出了一种高瓦斯、厚煤层两进两回回采工作面接续的巷道布置新方法，即：第1个工作面外圈巷道作第2个工作面内圈巷道使用，采用宽煤柱护巷；第1个工作面回采稳定后，在区段宽煤柱内沿采空区边缘布置第2个工作面瓦排巷，采用小煤柱护巷；新布置方法缩短了工作面外圈巷道的服务年限，显著改善了巷道围岩应力环境和维护状况，提高了资源回收率和巷道系统可靠性。现场应用效果表明，新的布置方法有效控制了两侧采动支承压力作用下煤柱内巷道围岩变形。

Investigation of multi entry gateroad layout in high gassy coal mines

In order to solve the maintenance difficulty of outer gateroad in “two intaks and two returns” ventilation mode in high gassy Longwall Top Coal Caving (LTCC)，theoretical analysis，numerical simulation and field trial were comprehensively applied to study in two respects：stress evolution and deformation characteristic of surrounding rock during drivage and retreating period；the relationship between gateroad performance and pillar width.On the basis of the stability mechanism of the gateroads and pillars subjected to dynamic loading two times in this project，an innovative approach to gateroad layout of highly gassy LTCC was put forward.An outer headgate of the 1st panel with wide pillar serves the 2nd panel as an inner tailgate.After the 1st panel is mined out，an outer tailgate of the 2nd panel is driven along the goaf with slender pillar in the barrier pillar of the 1st panel.This approach shortens the service life of outer tailgates，significantly improves loading environment and maintenance condition of gateroad，and increases coal recovery rate and gateroad system reliability.Field trial shows that the new approach effectively controls the gateroad deformation affected by the both sides dynamic loading，and meets the requirement for the tailgate cross sections in its service life.