基底泥岩非均匀膨胀作用的隧道仰拱变形规律分析  

Analysis of deformation law of tunnel inverted arch under non-uniform expansion of base mudstone

作　　者：许江波[1] 李强 刘一凡 程芳卉[2] 林晋海[2] 陈绍华[2] 詹皓辰 XU Jiang-bo;LI Qiang;LIU Yi-fan;CHENG Fang-hui;LIN Jin-hai;CHEN Shao-hua;ZHAN Hao-chen(School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China;China Railway First Survey and Design Institute Group Co.Ltd.,Xi'an 710043,Shaanxi,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]中铁第一勘察设计院集团有限公司,陕西西安710043

出　　处：《长安大学学报(自然科学版)》2025年第1期102-113,共12页Journal of Chang’an University(Natural Science Edition)

基　　金：青海省基础研究计划项目(2019-ZJ-7050)。

摘　　要：泥岩隧道仰拱在运营过程中常发生变形问题,基底围岩吸水膨胀后将直接影响仰拱的受力状态。为探究基底围岩非均匀膨胀作用下隧道仰拱的受力变形规律,依托兰新(兰州—新疆)高速铁路线路中的SJZ隧道,采用有限元软件ABAQUS对该泥岩隧道仰拱底鼓过程进行数值建模分析,采用热力学等效体积膨胀模拟基底围岩的不均匀膨胀,并结合现场围岩勘探数据和道面上拱监测数据,分析隧道仰拱底部病害的受力变形特征。研究结果表明:隧道仰拱结构的受力变形呈集中变化现象,隧道中部变形最大,并且向两端断面逐渐减小,隧道回填层表面的内力由膨胀中心区域向四周逐渐降低,仰拱底鼓量最大为28.2 mm,最大主应力为2.2 MPa,此时达到混凝土极限拉伸状态,导致隧道仰拱开裂;隧道仰拱不均匀底鼓与基底膨胀性围岩分布相关,围岩破碎引起的体积膨胀是导致隧道仰拱底鼓的主要原因;隧道仰拱在不均匀底鼓过程中,中心断面的最大主应力左侧为正,右侧为负,说明仰拱填充表面左侧受拉,右侧受压;仰拱回填层横向的竖向变形分为3段,靠近膨胀中心的轨道上方为主底鼓区,区内底鼓量基本一致,两侧底鼓为伴随性底鼓,且隧道底鼓量由中心沿两侧递减。研究结果可为泥岩隧道仰拱施工设计优化提供理论依据与技术参考。During the operation of mudstone tunnels,deformation issues are often experienced bythe inverted arch,and the stress state of the inverted arch is directly affected by the expansion ofthe base surrounding rock resulting from water absorption.To explore the stress-deformation lawof the tunnel inverted arch under the expansion of the base surrounding rock,based on the SJZtunnel of the Lanzhou-Xinjiang High-speed Railway,finite element software ABAQUS was usedto numerically model and analyzed the process of bottom heave of the mudstone tunnel invertedarch.The thermodynamic equivalent volume expansion model was used to simulate the non-uniform expansion of the base rock mass,and combined with on-site rock exploration data andarch monitoring data on the track surface,the stress and deformation characteristics of the tunnelarch bottom disease were analyzed.The results show that the stress anddeformation of the tunnel arch structure exhibit a concentrated variation phenomenon,with thedeformation in the middle of the tunnel being the largest and gradually decreasing towards the twoend sections.The internal force on the surface of the tunnel backfill layer gradually decreasesfrom the expansion center area to the surrounding areas.The maximum deformation amount of thearch bottom is 28.2 mm,and the maximum principal stress is 2.2 MPa.At this point,the concretereaches the ultimate tensile state,leading to cracking of the tunnel arch.The uneven bottomheave of the tunnel arch is related to the distribution of expansive surrounding rock at the base,and the volume expansion caused by rock fragmentation is the main reason for the bottom heaveof the tunnel arch.During the uneven bottom heaving process of the tunnel arch,the maximumprincipal stress on the center section is positive on the left and negative on the right,indicatingthat the filling surface of the arch is under tension on the left and compression on the right.The horizontal vertical deformation of the backfill layer of the inverted arch is divided into threesections.Th

关 键 词：隧道工程 仰拱底鼓 数值模拟 变形规律 

分 类 号：U451[建筑科学—桥梁与隧道工程]