超大直径盾构隧道管片结构力学行为与破坏特征研究  

Study on the Mechanical Behavior and Failure Characteristics of Ultra-large Diameter Shield Tunnel Segment Structures

作　　者：沐海星 封坤[1] 郭文琦 杨绍毅 张亮亮[2] MU Haixing;FENG Kun;GUO Wenqi;YANG Shaoyi;ZHANG Liangliang(Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu 610031;China Railway Siyuan Survey and Design Institute Group Co.,Ltd.,Wuhan 430063)

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,成都610031 [2]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《现代隧道技术》2025年第1期125-134,共10页Modern Tunnelling Technology

基　　金：国家自然科学基金(52078430).

摘　　要：为探明超大直径盾构隧道管片结构的力学行为与破坏特征,建立基于混凝土塑性损伤本构的管片结构三维精细化数值计算模型,研究极限荷载下管片结构整体竖向位移分布情况、接缝变形量、螺栓应力、钢筋应力、裂纹扩展及分布情况和承载力变化情况。研究结果表明:管片结构的整体位移分布呈漏斗状,中间环左右侧竖向位移分布不对称,结构单点竖向位移变化分为弹性阶段和弹塑性阶段,边环纵缝处竖向位移最大;结构破坏时,环缝最大张开量为0.075mm,最大错台量为0.308mm,纵缝最大张开量为4.92mm,最大错台量为3.58mm,但环向螺栓还未屈服,螺栓应力的变化过程可以分为线性减小、非线性增大和短暂下降3个阶段;结构破坏的主要特征为中间环内弧面先出现拉裂纹,裂纹更集中分布于中间环纵缝对应位置处,跨中处主筋屈服;当跨中主筋屈服时,截面安全系数为1.383,这说明用主筋屈服作为判断结构失效的依据是安全可行的。To investigate the mechanical behavior and failure characteristics of ultra-large diameter shield tunnel segment structures,a three-dimensional refined numerical calculation model of the segment structure based on con⁃crete plastic damage constitutive relations was developed.The study focuses on the distribution of overall vertical displacement,joint deformation,bolt stress,reinforcement stress,crack propagation and distribution,and changes in bearing capacity under ultimate load.The results show that the overall displacement distribution of the segment structure presents a funnel shape.The vertical displacement distribution on both sides of the middle ring is asym⁃metric.The change in single-point vertical displacement can be divided into two stages:elastic stage and elastoplastic stage,with the largest vertical displacement at the longitudinal joint of the side ring.When the structure fails,the maximum opening of the circumferential joint is 0.075 mm,the maximum misalignment is 0.308 mm,the maxi⁃mum opening of the longitudinal joint is 4.92 mm,and the maximum misalignment is 3.58 mm.However,the circum⁃ferential bolts have not yet yielded,and the bolt stress variation can be divided into three stages:linear decrease,nonlinear increase,and a brief drop.The main failure characteristic of the structure is the first appearance of tensile cracks on the inner arc surface of the middle ring,with cracks more concentrated in the corresponding position of the longitudinal joint.The main reinforcement at the mid-span yields.When the main reinforcement at the midspan yields,the safety factor of the section is 1.383,indicating that using main reinforcement yielding as a criterion for structural failure judgment is both safe and feasible.

关 键 词：超大直径 盾构隧道 管片结构 破坏特征 混凝土损伤塑性 数值模拟 

分 类 号：U451.4[建筑科学—桥梁与隧道工程]