盾构下穿引起无砟铁路轨道变形的计算方法  

Calculation Method for Calculating Rail Deflection of Ballastless Railway Caused by Tunnelling Underneath

作　　者：张茂斌 张丙强 ZHANG Maobin;ZHANG Bingqiang(Fujian Zhangzhou Highway Traffic Engineering Co.,Ltd.,Zhangzhou 363001,Fujian,China;School of Civil Engineering,Fujian University of Technology,Fuzhou 350118,China)

机构地区：[1]福建省漳州公路交通工程有限公司,福建漳州363001 [2]福建理工大学土木工程学院,福州350118

出　　处：《科技和产业》2025年第7期88-93,共6页Science Technology and Industry

基　　金：福建省自然科学基金(2023J01344)。

摘　　要：考虑无砟铁路路基沉降可能诱发轨道支承层与基层产生分离问题,提出下穿隧道盾构施工诱发无砟铁路轨道变形的计算方法。将无砟铁路道床板和支承层简化为叠合梁,并忽略扣件对叠合梁变形的影响,提出盾构下穿诱发无砟铁路叠合梁变形的简化方程。接着,将叠合梁分为脱空区和接地段,基于弹性地基梁理论求出盾构下穿诱发无砟铁路叠合梁变形解析解。然后,将钢轨视为通过线性弹簧联系在叠合梁上的Euler梁,推导出叠合梁变形引起钢轨变形的计算公式。在此基础上,通过与既有文献数值模拟和理论解析结果对比,验证提出的盾构下穿引起无砟铁路轨道变形简化方法的正确性。最后,对盾构下穿引起无砟铁路轨道变形进行参数敏感性分析,包括隧道施工引起周围地层损失率、叠合梁抗弯刚度、扣件刚度和轨道抗弯刚度。研究表明:忽略无砟铁路支承层局部脱空效应,将导致盾构下穿引起钢轨变形计算结果偏大;减小隧道施工引起周围地层损失率、加固叠合梁和加固钢轨均能控制钢轨变形,但加固扣件刚度却增大轨道变形不平顺度。Considering the effect of the separation between the supporting layer and the base layer of the ballastless railway caused by foundation settlement,a simplified method was proposed for calculating the rail deformation of the ballastless railway to tunnelling underneath.Firstly,the track slab and the supporting layer were supposed as a composite elastic beam,and a simplified equation for the deformation of ballastless railway composite beams induced by shield tunneling was proposed by ignoring the influence of fasteners on the composite beam deformation.Afterwards,the composite beam was divided into a void zone and a joint zone,and the analytical solutions for the deformations of the composite beams caused by tunnlling underneath were proposed based on the elastic foundation beam theory.Furthmore,the rail was regarded as an Euler beam connecting with the composite beam by the dispersed spring,and the equations for the rail deformation caused by the composite beam deformation were derived.Based on the above,compared with the numerical simulation and theoretical results in the existing literature,the proposed simplified method of the ballastless railway caused by tunneling underneath was validated.Finally,the influences of model parameters on the rail deformation to tunnelling underneath were discussed,including the tunnelling induced ground loss rate,the composite beam bending stiffness,the fastener stiffness,and the rail bending stiffness.The results indicate that the theoretical calculation results were overestimated by neglecting the local suspension effect of the supporting layer.Reducing the tunnelling induced ground loss rate,strengthening the composite beams and rails can control the rail deformation of the ballastless railway caused by tunnlling undercrossing,but strengthening the fasteners stiffness may increase the unevenness of rail deformation.

关 键 词：轨道变形 隧道下穿 无砟铁路 叠合梁 理论方法 

分 类 号：U25[交通运输工程—道路与铁道工程]