摘要
【目的】以小浪底北岸灌区水利枢纽工程为研究对象,旨在探究局部洞段开挖支护后的大变形现象,分析强降雨条件下砂泥岩互层隧洞围岩侧向变形机制,并提出合理的隧洞开挖支护措施。【方法】运用现场调查、现场监测和数值模拟相结合的研究手段,对不同工况下隧洞围岩侧向变形、塑性区特征以及支护单元受力状况展开研究。【结果】结果显示,初始工况下隧洞侧壁最大位移量相对较小,围岩基本稳定。降雨工况下,隧洞底脚侧向变形较大,钢拱架等支护设备破坏。降雨加支护工况下,侧壁最大侧向位移量几乎可以忽略,支护效果良好。【结论】隧洞侧向变形为渐进过程。9^(#)隧洞围岩侧向变形机制如下:局部软弱岩层透镜体影响稳定性;强降雨入渗与农业灌溉致地下水位抬升,增加孔隙水压并降低围岩强度,致使原支护结构承载力不足,无法限制变形发展致其损坏并引发大变形。增设底部横向支撑可显著抑制围岩侧向变形,两侧底脚处效果明显,“增设底部横向钢支撑+沿洞周2 m注浆加固”的支护优化方案效果较佳。
[Objective]The water conservancy project in the north bank irrigation area of Xiaolangdi was taken as the research object,aiming to explore the large deformation phenomenon after excavation and support of local tunnel section,analyze the lateral deformation mechanism of surrounding rock of sand-mudstone interbedded tunnel under heavy rainfall conditions,and put forward reasonable tunnel excavation and support measures.[Methods]By means of field investigation,field monitoring and numerical simulation,the lateral deformation of tunnel surrounding rock,the characteristics of plastic zone and the stress state of supporting unit under different working conditions were studied.[Results]The results show that the maximum displacement of the side wall of the tunnel is relatively small under the initial condition,and the surrounding rock is basically stable.Under the condition of rainfall,the lateral deformation of the tunnel foot is large,and the supporting equipment such as steel arch is destroyed.Under the condition of rainfall and support,the maximum lateral displacement of the side wall can be almost ignored,and the support effect is good.[Conclusion]The lateral deformation of the tunnel is a gradual process.The lateral deformation mechanism of surrounding rock of 9^(#)tunnel is as follows:the lens of local weak rock layer affects the stability;heavy rainfall infiltration and agricultural irrigation caused the rise of groundwater level,increased pore water pressure and reduced the strength of surrounding rock,[Results]ing in insufficient bearing capacity of the original supporting structure,which could not limit the development of deformation and cause large deformation.Adding transverse support at the bottom can significantly inhibit the lateral deformation of surrounding rock,and the effect is obvious at the bottom feet on both sides.The support optimization scheme of‘adding transverse steel support at the bottom+grouting reinforcement along 2 m around the hole’is better.
作者
赵本超
苏昆琨
蔡茂泽
秦承志
刘海宁
裴书锋
刘亮
ZHAO Benchao;SU Kunkun;CAI Maoze;QIN Chengzhi;LIU Haining;PEI Shufeng;LIU Liang(Henan Haihe River Basin Water Resources Management Center,Xinxiang 453000,Henan,China;Henan Water Investment Group Xiaolangdi North Bank Irrigation Engineering Co.,Ltd.,Zhengzhou 450003,Henan,China;College of Earth Science and Engineering,North China University of Water Resources and Electric Power,Zhengzhou 450046,Henan,China)
出处
《水利水电技术(中英文)》
北大核心
2025年第6期149-161,共13页
Water Resources and Hydropower Engineering
基金
小浪底北岸灌区工程隧洞围岩变形失稳机理与高外水压力渗控关键技术研究与应用(20020183061)
2023年河南省重大科技专项(231100320100)
国家自然科学基金(42302276,52409157)。
关键词
软岩互层
隧洞
侧向变形
破坏机理
支护优化
监测模拟
soft rock interbedded
tunnel
lateral deformation
failure mechanism
support optimization
monitoring simulation
作者简介
赵本超(1989-),男,工程师,学士,主要从事工程管理方向研究。E-mail:594092595@qq.com;通信作者:蔡茂泽(2000-),男,硕士研究生,主要从事隧道工程研究。E-mail:cmz15769468544@163.com。
