摘要
沿空掘巷可有效提高煤炭资源回收率,改善采掘接替关系,但存在施工维护难度大的难题。为了提高沿空巷道围岩稳定性并减少煤炭损失量,以布尔台煤矿42108辅运巷为研究背景,通过理论分析确定了巷道塑性区发育特征,建立数值模型综合确定了合理煤柱宽度并进行了工业性实践。研究结果表明:42108辅运巷掘出后在采动影响下具有帮部大变形特征,辅运巷塑性区呈非对称蝶形分布的形态,塑性区发育范围为1.8~2.7 m;结合极限平衡理论及数值模拟认为,煤柱宽度大于30 m时其内部出现明显的应力降低区,有利于巷道维护,同时考虑煤炭资源回收率,确定合理煤柱宽度为30 m;揭示了多次补强支护仍无法有效控制巷道变形量的原因为锚索易拉伸破断,在此基础上提出了柔性锚索支护方案,同时将帮部锚杆间排距减小至750 mm×750 mm,经现场实践后30 d内两帮最大变形量160 mm,围岩控制效果显著。
Roadway driving along goaf can effectively improve the recovery rate of coal resources and the mining replacement relationship,but it is difficult to construct and maintain.In order to improve the stability of surrounding rock of gob side entry and reduce coal loss,taking 42108 auxiliary haulage roadway of Bultai Coal Mine as the research background,the development characteristics of plastic zone of roadway are determined through theoretical analysis,a numerical model is established to comprehensively determine the reasonable width of coal pillar and industrial practice is carried out.The research results show that the 42108 auxiliary haulage roadway has the characteristics of large deformation of the side under the influence of mining after being excavated.The theoretical analysis results show that the plastic zone of the auxiliary haulage roadway is distributed in an asymmetric butterfly shape,and the development range of the plastic zone is 1.8-2.7 m.Combined with limit equilibrium theory and numerical simulation,it is considered that when the width of coal pillar is greater than 30 m,there is an obvious stress reduction area in its interior,which is conducive to roadway maintenance.At the same time,considering the recovery rate of coal resources,the reasonable width of coal pillar is determined to be 30 m.It is revealed that the reason why the tunnel deformation cannot be effectively controlled by multiple reinforcement support is that the anchor cable is easy to stretch and break.On this basis,a flexible anchor cable support scheme is proposed,and the row spacing between the side bolts is reduced to 750 mm× 750 mm,the maximum deformation of both sides within 30 days after field practice is 160 mm,and the surrounding rock control effect is significant.
作者
杨永亮
杨森
YANG Yongliang;YANG Sen(CHN Energy,Shendong Coal Group Co.,Ltd.,Shenmu 719315,China;CCTEG,Xi’an Research Institute(Group)Co.,Ltd.,Xi’an 710077,China)
出处
《中国矿业》
2023年第10期136-143,共8页
China Mining Magazine
关键词
大变形巷道
塑性区演化
数值模拟
柔性锚索
large deformation roadway
evolution of plastic zone
numerical simulation
flexible anchor cable
