摘要
我国煤矿主要通过井工开采,每年新掘约12000公里的巨大巷道工程,90%以上的煤矿巷道采用锚杆、锚索支护。通过引入巷道临空面有限边界条件,基于应力叠加原理,提出矩形巷道顶板锚杆应力扩散模型,推导锚杆预紧力对围岩提供的附加应力计算公式,提出考虑预紧力作用的围岩强化力学模型,并通过FLAC^(3D)数值模拟验证所提模型的正确性,最后研究锚杆参数对围岩强化效果的影响。研究结果表明:锚杆群情况下,预紧力在围岩中产生的竖向附加应力最小值出现在两根锚杆中心位置,锚固体强度随着锚杆预紧力线性增加,随着锚杆间距的增加非线性降低,但随着锚杆长度呈现先增加后减小的趋势,不能通过盲目增加锚杆长度来提高围岩加固效果。
In China,coal mining primarily relies on underground extraction,resulting in the annual excavation of about 12000 kilometers of massive tunnels,with over 90%using rock bolts and cable bolts for support.This study introduces a stress diffusion model for rectangular tunnel roof rock bolts,considering finite boundary conditions and stress superposition principles.It derives formulas for additional stress from bolt pre-tension and proposes a mechanical model for rock mass reinforcement.FLAC^(3D) simulations validate the model,which is then used to study how bolt parameters affect reinforcement.Key findings show that in bolt groups,minimum vertical additional stress occurs between bolts,anchored body strength increases linearly with pre-tension,reinforcement decreases nonlinearly with increased bolt spacing,and exhibits a peak with bolt length,indicating that simply increasing length doesn't always improve reinforcement.
作者
张镇
林健
马彬
褚晓威
任硕
李中伟
郑允
ZHANG Zhen;LIN Jian;MA Bin;CHU Xiaowei;REN Shuo;LI Zhongwei;ZHENG Yun(Coal Mining and Designing Department,Tiandi Science and Technology Co.,Ltd.,Beijing 100013,China;CCTEG Coal Mining Research Institute,Beijing 100013,China;Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2024年第S02期3681-3689,共9页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(52004126,51774186)
中国科学院青年创新促进会(2022333)
关键词
采矿工程
应力扩散
强化机制
预紧力
黏聚力
mining engineering
stress diffusion
reinforcement mechanism
pre-tension force
cohesion
