考虑围岩短期蠕变效应的隧道双层初期支护变形控制研究  

Study on deformation control of double-layered initial support in tunnels considering short-term creep effects of surrounding rock

作　　者：杨林霖 杨文波[1] 田浩晟 寇昊 张航 刘冲亮 杨侨伟 何川[1] YANG Linlin;YANG Wenbo;TIAN Haosheng;KOU Hao;ZHANG Hang;LIU Chongliang;YANG Qiaowei;HE Chuan(Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;Sichuan Highway Planning,Survey,Design and Research Institute Ltd.,Chengdu,Sichuan 610041,China;China Construction Infrastructure Co.,Ltd.,Beijing 100044,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,四川成都610031 [2]四川省公路规划勘察设计研究院有限公司,四川成都610041 [3]中国建设基础设施有限公司,北京100044

出　　处：《岩石力学与工程学报》2023年第7期1731-1742,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：四川省杰出青年科技人才项目(2022JDJQ0018)。

摘　　要：以华丽高速东马场1号隧道为工程背景,基于单轴压缩蠕变试验与现场监测,对泥质粉砂岩短期蠕变特征与蠕变参数进行分析,探究考虑围岩短期蠕变效应与施工扰动耦合影响下的隧道施工力学行为,在此基础上分析中台阶长度、第二层初期支护施作时机与初支封闭时间对隧道支护效果的影响以及敏感性。研究结果表明:不考虑围岩短期蠕变效应时,计算结果中拱底位移缩小了27.03%,塑性区面积缩小了16.91%;不同施工关键参数对隧道不同位置的变形控制效果存在差异;改变中台阶长度与第二层初期支护施作时机可以有效分配第一层与二层初期支护受力,初支封闭越早对支护结构受力越有利;敏感性分析结果:中台阶长度>第二层初支支护时机>初支封闭时间;可遵循“台阶增长、快支快封;台阶缩短、慢支慢封”的原则进行施工调控。Taking the Dongmachang No.1 tunnel of Huali Railway as the background,the short-term creep characteristics and creep parameters of muddy siltstone were analyzed by the uniaxial compression creep test and field monitoring,and the mechanical behavior of tunnel construction considering the coupling effect of short-term creep effect of surrounding rock and construction disturbance was explored.Then,the influence and the sensitivity of the mid-step length,the second layer of initial support installation timing as well as the initial support closure time on the tunnel support effects were analyzed.The results show that when the short-term creep effect of the surrounding rock is not taken into account,the displacement of the arch base is reduced by 27.03%and the area of the plastic zone is reduced by 16.91%in the calculation results.Different construction parameters have different effects on deformation control of each part of the tunnel.Changing the length of the mid-step and the timing of second layer initial support installation may efficiently distribute the support force of the first and second layers of the initial support;the earlier the initial support closure,the better the state of force in the tunnel.Sensitivity analysis results:mid-step length>second layer of initial support installation timing>initial support closure time.Construction control can be carried out according to the principle of“step growth,fast support and fast sealing;step shortening,slow support and slow sealing”.

关 键 词：隧道工程 短期蠕变 三台阶法 双层初期支护 施工关键参数 敏感性分析 

分 类 号：U45[建筑科学—桥梁与隧道工程]