软岩大变形巷道破坏机理与支护技术

(1.西安科技大学 能源学院,陕西 西安 710054; 2.西安科技大学 西部矿井开采及灾害防治教育部重点实验室,陕西 西安 710054; 3.陕煤集团韩城矿业有限公司 象山矿井,陕西 韩城 715400)

石门; 软岩; 变形规律; 破坏机理; 自稳平衡圈理论

Failure mechanism and support technology in soft rock large deformation roadway
HUANG Qing-xiang1,2,GUO Qiang1,2,CAO Jian1,2,QIAN Wan-xue3,HOU Ting3,ZHAO Xuan3

(1.College of Energy Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.Key Laboratory of Western Mine Exploitation and Hazard Prevention,Ministry of Education,Xi'an University of Science and Technology,Xi'an 710054,China; 3.Xiangshan Coal Mine,Shaanxi Coal Group Hancheng Mining Co.,Ltd.,Hancheng 715400,China)

cross-cut; soft rock; deformation characteristics; failure mechanism; theory of self-stable ring

备注

针对软岩大变形巷道围岩控制难题,以象山矿井南一石门为工程背景,采用现场取样、物理相似模拟和FLAC3D数值计算,分析了巷道围岩物理力学性质,掌握了巷道各阶段围岩基本变形规律,得出巷道变形表现为四周收敛,具有明显的软岩特征,变形速度达3~4 mm/d.研究发现:巷道底板极限平衡区最大深度为3.57 m,两帮极限平衡区最大深度为1.86 m,顶板极限平衡拱高度为4.26 m.基于上述分析,结合“自稳平衡圈理论”,提出合理的巷道支护方案,采用直墙圆弧拱带反拱优化断面,确定了全断面采用锚杆锚索+钢筋梯子梁+金属网喷浆支护,对围岩极其破碎阶段进行注浆,顶锚杆长度2.4 m,锚索长度6 m; 帮锚杆长度2.4 m,锚索长度4 m; 底板采用长度1.5 m的注浆锚杆,全断面采用金属网喷浆封闭。该研究方案已被矿区采纳。

With No.1 south crosscut in Xiangshan Coal Mine as an example,the physical and mechanical parameters of surrounding rock of roadway were measured through site sampling,physical simulation and FLAC3D numerical simulation,the physical and mechanical parameters based on the surrounding rock control of soft large deformation roadway,which revealed the deformation characteristics of surrounding rock at different stages of roadway.It can be found that deformation represents convergence all around the roadway,having obvious soft rock characteristics,and the deformation velocity reaches 3~4 mm per day.The results show that:the largest depth of limit equilibrium zone in roadway floor is 3.57 m,the largest depth of limit equilibrium zone in roadway ribs is 1.86 m,and the height of limit equilibrium arch in roadway roof is 4.26 m.Based on the analysis above,coupled with the “theory of self-stable ring”,the reasonable support scheme of roadway was put forward,straight wall circular arch with reverse arch was applied to optimize the roadway section,all section with the bolt and cable,steel beam and shotcreting with wire mesh was adopted in roadway support,and grouting was used in extreme broken stage of roadway.The length of roof bolt is 2.4 m,the length of cables is 6m,the bolts length of roadway rib is 2.4 m and the cable length is 4m,grouted bolt of 1.5 m is adopted in roadway floor,shotcreting with wire mesh was applied at all sections of roadway.The support scheme has been adopted by the coal mine.