软岩小净距公路隧道设计优化及稳定性研究  

Study on Construction Design Optimization and Stability of Small Clear Spacing Highway Tunnel in Weak Rock

作　　者：刘二强 LIU Er-qiang(Guangdong Transportation Planning and Design Institute Group Co.,Ltd,Guangzhou 510000,Guangdong,China)

机构地区：[1]广东省交通规划设计研究院集团股份有限公司,广东广州510000

出　　处：《广东交通职业技术学院学报》2023年第1期21-27,共7页Journal of Guangdong Communication Polytechnic

摘　　要：小净距隧道施工一直是工程建设中的难题,尤其是不良地质条件下的隧道开挖,施工灾害问题尤为突出。为确保软岩隧道的施工安全,以某小净距公路隧道为工程背景,通过计算模拟,基于现场试验,提出地表沉降控制技术,建立优化支护结构方案。现场监测数据分析结果表明:地表沉降变形的发展表现为变形快速发展阶段、变形缓慢发展阶段和变形平稳阶段,隧道开挖对近地表围岩变形的影响范围约为2.5倍洞径。深仰拱和锁脚锚杆技术在现场实施后,测得围岩拱顶沉降和水平收敛分别控制在97.33 mm和44.23 mm,约束围岩变形效果明显,最终结构受力也较为均匀。设计优化的成功实施可为类似隧道工程提供借鉴和参考。The small clear spacing tunnels has always been a challenge in tunnel construction,especially tunneling in unfavorable geological conditions,and construction disasters are particularly prominent.In order to ensure the construction safety of the small spacing tunnel constructed in weak surrounding rock,taking a small clear spacing tunnel as an example,combining the field test,the ground settlement control technology was proposed,and the supporting structure was optimized according to the site geological conditions.The measurement data indicated that ground settlement can be divided into rapid displacement stage,slow displacement stage and stabilization stage.The influence range of tunnel excavation on ground settlement is about 2.5 times the tunnel diameter.After the implementation of the deeper inverted arch and foot-lock bolts,the arch settlement and horizontal convergence were controlled within the 97.33 mm and 44.23 mm,respectively,which validates a significant constraint effect for surrounding rock deformation;in addition,the structural stress was relatively uniform.The successful application of these technologies in the case can provide technical support for the construction of similar small clear spacing tunnels.

关 键 词：软弱围岩 小净距隧道 施工技术优化 围岩变形与受力 监控量测 

分 类 号：U455.4[建筑科学—桥梁与隧道工程]