垂直顶升作用下盾构隧道力学特性模型试验研究  

Experimental Study on the Mechanical Characteristics of Shield Tunnels under Vertical Jacking

作　　者：杨春山 徐世杨 魏立新 陈俊生[3] YANG Chunshan;XU Shiyang;WEI Lixin;CHEN Junsheng(Guangzhou Municipal Engineering Design&Research Institute CO.,Ltd,Guangzhou 510060;Guangzhou Metro Design&Research Institute Co.,Ltd.Guangzhou 510010;State Key Laboratory of Subtropical Building Science,South China University of Technology,Guangzhou 510640)

机构地区：[1]广州市市政工程设计研究总院有限公司,广州510060 [2]广州地铁设计研究院股份有限公司,广州510010 [3]华南理工大学亚热带建筑科学国家重点实验室,广州510640

出　　处：《现代隧道技术》2024年第5期210-218,共9页Modern Tunnelling Technology

基　　金：国家自然科学基金项目(51878192);广东省住房和城乡建设厅科技创新计划项目(2022-K4-094918);广东省普通高校特色创新项目(2023KTSCX261)。

摘　　要：垂直顶升法施工中,顶升反力作用于盾构隧道底部产生的影响是关乎土层结构安全、稳定的关键问题。为了探究盾构内垂直顶升施工对隧道力学特性的影响,依托典型工程,通过研制试验装置开展垂直顶升模型试验,揭示顶升过程扩散块反力的发展规律,探索顶升阶段盾构隧道衬砌结构与接头受力变形特性,并与理论计算进行对比分析。研究结果表明:顶升反力分布呈现出典型的非线性特征,主要经历土层破坏前的显增段、土层破坏后的显降段以及后期的渐降稳定段。管片收敛变形经历显著增加→快速减小→缓慢下降→趋于稳定4个阶段,影响范围为开口环与相邻两环,顶升过程变形控制应结合位移特征重点考虑竖向加固。顶升阶段隧道纵向弯曲变形,最大张开量出现在开口环间,且因纵向荷载突变错动,最大错台量出现在开口环与相邻环间。隧道管片环缝张开和错台沿纵向衰减很明显,位移主要由管片本体变形组成,接头变形贡献很小。顶升力作用下拱顶和底内侧分别受拉、受压,应力先增大后减小,拱腰上部表现为先压后拉,下部则受拉。顶升反力诱发管片应力扰动重分布,主要影响开口环以及相邻环,管片应力水平较低,结构未出现拉压损伤。In vertical jacking construction,the effect of jacking reaction forces applied to the bottom of shield tunnels is a critical issue concerning the safety and stability of the surrounding soil structure.To explore the impact of vertical jacking construction on the mechanical behavior of shield tunnels,a model test was conducted using a test apparatus developed for a typical project.The test aimed to reveal the development pattern of the reaction force distribution during the jacking process and to study the mechanical and deformation characteristics of the tunnel lining and joints during different jacking stages,comparing them with theoretical calculations.The results indicate that the distribution of jacking reaction forces exhibits a typical nonlinear pattern,characterized by a significant increase before soil failure,a notable decrease after soil failure,and a gradual stabilization phase.The convergence deformation of tunnel segments undergoes four stages:a sharp increase,rapid decrease,slow decline,and eventual stabilization,affecting the opening ring and adjacent two rings.Deformation control during the jacking process should prioritize vertical reinforcement based on displacement characteristics.Longitudinal bending deformation occurs in the tunnel during the jacking stage,with the maximum gap observed between the opening rings.Due to sudden longitudinal load shifts,the largest misalignment occurs between the opening ring and adjacent rings.The segment ring joint opening and misalignment decrease significantly along the longitudinal axis,with displacement mainly resulting from segment body deformation and minimal joint deformation contribution.Under jacking forces,the tunnel crown and inner base are subject to tension and compression,respectively,with stress initially increasing and then decreasing.The upper part of the tunnel waist experiences initial compression followed by tension,while the lower part is under tension.The jacking reaction force induces a redistribution of segment stress disturbances,primar

关 键 词：盾构隧道 垂直顶升 顶升反力 力学特性 模型试验 理论分析 

分 类 号：U456[建筑科学—桥梁与隧道工程]