浸水含瓦斯抽采钻孔煤柱稳定性研究及控制

Study on the stability and control of coal pillars in water-bearing gas extraction boreholes

窄煤柱护巷可有效提高煤炭资源采出率,改善采掘接替关系,但施工维护难度大,尤其是在采空区积水且矿井瓦斯含量较高的条件下,煤柱稳定性控制显得更为重要。基于石泉煤矿30108工作面沿空巷道掘进及支护的工程背景,结合钻孔可视化探测技术提出了一种基于MATLAB图像处理的钻孔裂隙定量表征方法。综合浸水煤柱力学模型和数值模拟,确定了合理煤柱宽度,提出了采空区疏水及“锚索网梁+窄煤柱侧索梁补强+窄煤柱侧注浆加固”的巷道高强非对称支护方案,并进行了工业性实践。研究结果表明:钻孔截面中裂隙面积占比随钻孔深度增加呈负对数减小趋势,煤柱宽度为10.00 m时正常区段及含瓦斯抽采钻孔区段的煤柱内部均存在较大范围的弹性区,具备较强的承载能力;相应支护方案控制效果较好,具有显著的经济效益。

Narrow-coal-pillar entryprotection can effectively increase the recovery rate of coal resources and improve the relationship between mining and replacement.However,there are problems in construction and maintenance,especially under the condition of water accumulation in goaf and high gas content in mine,it is important to the stability of coal pillar.Based on the engineering background of goaf side entry driving in 30108 working face of Shiquan Coal Mine,a quantitative characterization method of borehole crack based on MATLAB image processing was proposed in combination with the visual detection technology of drillings.On the basis of mechanical model and numerical simulation of immersed coal pillar,the reasonable width of coal pillar was determined,the drainage scheme of goaf and the high-strength asymmetric support scheme of roadway“anchor cable net beam+reinforcement of narrow coal pillar side cable beam+reinforcement of narrow coal pillar side grouting”were proposed and the industrial practice was carried out.The research results show that the proportion of fracture area in the borehole section decreases in negative logarithm with the increase of borehole depth.When the coal pillar width is 10.00 m,there is a large range of elastic zones in the coal pillar in the normal section and the gas drainage drilling section,which has a strong bearing capacity.The roadway control effect has remarkable control effect and significant economic benefits.