摘要
以信湖煤矿典型深部软岩巷道为工程背景,依据巷道围岩应力变化趋势及围岩强度变化,按照深部软岩巷道四线段全应力-应变曲线划分围岩次生承载结构为"流动层-塑性软化层-塑性硬化层-弹性层"耦合承载层,塑性软化层、塑性硬化层组成塑性承载区。并根据巷道围岩承载层划分提出动态补强支护方案:一次支护采用锚网喷支护,二次补强选取浅、深孔注浆锚杆锚索联合支护,结合支护方案特点提出"层-双拱"承载结构力学模型,在极限平衡条件下对"层-双拱"承载结构进行受力分析得到其极限承载强度解析式,工程计算得到信湖煤矿一水平回风石门经"层-双拱"承载结构支护后极限承载强度可达29.30 MPa,理论验证了支护方案的可靠性。同时,现场监测结果表明:回风石门在动态补强支护后巷道围岩变形趋于平稳,巷道顶板最大下沉量仅为36 mm,两帮移近量为67 mm,巷道能够保持长期稳定。
Taking a typical deep soft rock roadway of Xinhu coal mine as the engineering background,the bearing structure of the surrounding rock is divided into fluid,plastic softening,plastic hardening and elastic layers according to the variations of stress and strength of the surrounding rock,and the plastic softening and hardening layers form a plastic bearing zone.A dynamic reinforcement support scheme is proposed which includes the first support of anchor net spray and the second reinforcement of shallow and deep hole grouting jointed bolts and cables,and a mechanical model of the layer-double arch bearing structure is proposed in combination with the characteristics of the support scheme.Under the limit equilibrium condition,the forces acting at the layer-double arch bearing structure are analyzed and a formula for calculating the ultimate bearing strength is obtained.The engineering calculation shows that the ultimate bearing capacity of the air returning cross-cut of Xinhu coal mine reaches 29.30 MPa after the surrounding rock is reinforced by the proposed support scheme and that the support scheme is reliable.The on-site monitoring results show that,after the dynamic reinforcement support,the surrounding rock deformation of the roadway tends to be stable with only 36 mm of the subsidence of the roadway roof and 67 mm of the displacement of roadway’s two side walls,and that the roadway can maintain long-term stability.
作者
李英明
赵呈星
刘增辉
孟祥瑞
彭瑞
LI Yingming;ZHAO Chengxing;LIU Zenghui;MENG Xiangrui;PENG Rui(School of Mining and Safety Engineering,Anhui University of Science and Technology,Huainan,Anhui 232001,China;Key Laboratory of Safe and Effective Coal Mining of the Ministry of Education,Anhui University of Science and Technology,Huainan,Anhui 232001,China;School of Safety Engineering,North China Institute of Science and Technology,Beijing 101601,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2020年第2期217-227,共11页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(51574006,51874002,51774008)。
关键词
岩石力学
深部软岩巷道
围岩应力
动态补强支护
工程实践
“层-双拱”承载结构
rock mechanics
deep soft rock roadway
surrounding rock stress
dynamic reinforcement support
engineering practice
layer-double arch bearing structure
