循环进尺对隧道洞口段施工动态稳定性影响研究  

Study on the Influence of Cycle Footage on the Dynamic Stability of Tunnel Portal Section Construction

作　　者：李文涛[1] 赵旭[1] 郭飞 陶连金[1] 黎若寒 Li Wentao;Zhao Xu;Guo Fei;Tao Lianjin;Li Ruohan(Faculty of Architecture,Civil and Transportation Engineering,Beijing University of Technology,Beijing 100124,China;Beijing Municipal Construction Co.,Ltd.,Beijing 100048,China;College of Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]北京工业大学城市建设学部,北京100124 [2]北京市政建设集团有限责任公司,北京100048 [3]同济大学土木工程学院,上海200092

出　　处：《市政技术》2024年第6期60-67,共8页Journal of Municipal Technology

基　　金：国家重点研发计划“高山峡谷工程区复合链生灾害风险推演关键技术”项目(2022YFC3004300)。

摘　　要：研究施工过程中隧道-围岩相互作用和破坏机理对维持结构稳定至关重要,采用有限元软件建立了福建省福州市罗汉山隧道计算模型,讨论了施工过程中围岩和结构位移及塑性区发展,基于强度折减法分析了考虑前切面和不同循环进尺下隧道模型的安全系数变化规律。通过分析可知,隧道洞口段围岩和边坡中塑性区贯通发育是其破坏的主要原因,塑性区贯通后边坡进入失稳状态,进而将荷载和变形传递给隧道结构;通过强度折减法获得了不同循环进尺下的安全系数,循环进尺越小隧道洞口段的边坡稳定性越高。研究成果可为隧道洞口段施工稳定性的估计和失稳预测提供理论依据。During the construction process,it is important to study the interaction and failure mechanism between tunnel and surrounding rock to maintain the stability of the structure.The calculation model of Luohanshan tunnel in Fuzhou,Fujian Province was established by finite element software.The displacement and plastic zone development of surrounding rock and structure were discussed.Based on the strength reduction method,the dynamic safety factor changes of the tunnel model considering the front section and different advance per round were analyzed.Through the analysis,it is found that the main cause of failure is the development of the surrounding rock of the tunnel entrance and the plastic zone of the slope.After the connection of the plastic zone,the slope appears to be unstable,and then the load and deformation are transferred to the tunnel structure;The strength reduction method is used to obtain the safety factor under different cyclic penetration,the smaller the cyclic penetration,the higher the slope stability of tunnel entrance section.The research results can provide theoretical basis for the construction stability estimation and instability prediction in tunnel entrance section.

关 键 词：隧道 洞口段 循环进尺 稳定性 强度折减法 安全系数 

分 类 号：U455[建筑科学—桥梁与隧道工程]