深部特厚煤层综放沿空掘巷煤柱优化及巷道支护

Optimization of coal pillar and tunnel support for fully mechanized caving along gob in deep and extra thick coal seams

为研究深部大采高综放工作面窄煤柱沿空掘巷巷道矿压控制问题,以国能宁煤集团枣泉煤矿2^(-2)特厚煤层130203大采高综放工作面回风巷道为背景,基于实用矿山压力理论,建立了巷道围岩内、外应力场动态结构力学模型,运用理论计算和数值计算针对不同尺寸煤柱煤体应力对比分析,将原留设15 m护巷煤柱缩小至5 m进行了煤柱优化。结果表明:在稳定的内应力场掘巷有利于巷道的稳定性,避免了顶板事故及冲击地压相关灾害的发生,现场5 m小煤柱护巷工程应用中,130203回风巷道小煤柱侧变形量为1050 mm,实体煤帮变形量为400 mm,两帮呈现不对称性变形,底板局部底鼓量为1400 mm;深部特厚煤层综放开采沿空掘巷采用5 m小煤柱护巷方案设计正确,极大改善了巷道围岩的应力环境,整体设计满足生产要求,现场应用良好。130203工作面小煤柱沿空掘巷技术成功应用,为矿井开采提供了可靠的科学依据。

In order to study the control of mining pressure in narrow coal pillars along goaf roadway in deep high mining and fully mechanized top coal caving face,the return air roadway of 130203 high mining and fully mechanized top coal caving face in the 2^(-2)thick coal seam of Zaoquan coal mine of Guoneng Ning Coal Group is taken as the engineering object.Based on the practical mining pressure theory,a dynamic structural mechanical model of the internal and external stress fields in the surrounding rock of the roadway was established.Theoretical and numerical calculations were carried out to compare and analyze the stress of coal pillars of different sizes.The original 15 m protective roadway coal pillar was reduced to 5 m for coal pillar optimization.The results indicate that excavating tunnels in a stable internal stress field is beneficial for the stability of the tunnels,which avoids the occurrence of roof control and rockburst related disasters and accidents.Through the application of a 5m small coal pillar protection tunnel project on site,the deformation on the side of the small coal pillar in the 130203 return air tunnel is 1050 mm,and the deformation on the solid coal wall is 400 mm.The two sides show asymmetric deformation,and the local floor bulge on the bottom plate is 1400 mm.The design scheme of using a 5 m small coal pillar to protect the roadway along the goaf in deep and thick coal seam fully mechanized top coal caving mining is reasonable,greatly improving the stress environment of the surrounding rock of the roadway.It has been well applied on site,and the overall design meets the production requirements.The successful application of small coal pillar tunneling technology along the goaf in the 130203 working face provides a reliable scientific basis for the mining of mines.