重载铁路非饱和路基三维动力响应分析  

Three-dimensional Dynamic Response Analysis of Unsaturated Subgrade in Heavy-haul Railways

作　　者：杜业峰 崔新壮[1,2] 包振昊 李向阳 郝建文 张圣琦 DU Yefeng;CUI Xinzhuang;BAO Zhenhao;LI Xiangyang;HAO Jianwen;ZHANG Shengqi(School of Civil Engineering,Shandong University,Jinan 250061,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China)

机构地区：[1]山东大学土建与水利学院,山东济南250012 [2]重庆大学土木工程学院,重庆400045

出　　处：《铁道学报》2025年第3期118-125,共8页Journal of the China Railway Society

基　　金：国家自然科学基金(52027813,52178429,51778346);山东省自然科学基金(ZR2020ME242)。

摘　　要：基于扩展Biot孔隙理论,建立交通荷载作用下轨道-轨枕-道砟-非饱和路基耦合三维动力学模型;利用双重Fourier变换得到频域内路基土三维动力响应的半解析解;采用数值积分方法得到土体动力响应时程曲线,并计算出土体的应力路径;在大秦重载铁路开展动应力现场测试,验证动力学模型的正确性,研究不同列车轴重、速度、土体饱和度等对非饱和路基三维动力响应和应力路径的影响。结果表明:列车速度对水平正应力σ_(x)和σ_(y)影响显著,而对竖向正应力σ_(z)和剪应力τ_(xz)的影响并不明显;各项动力响应参数均随着列车轴重的增加而等比提高;随着深度的变化,各项动力响应曲线的波形也会随之变化,深度越深,曲线峰值个数越少;移动列车荷载会引起路基土单元应力主轴旋转,随着深度的增加,应力路径逐渐由四圈缩减为一圈。该研究对重载铁路路基结构设计与服役性能提升具有重要理论价值。A three-dimensional dynamic model of track-sleeper-ballast-unsaturated subgrade coupling under traffic stresses was constructed based on the extended Biot pore theory.Using the dual Fourier transform,a semi-analytic solution was found for the three-dimensional dynamic response of subgrade soil in the frequency domain.The numerical integration approach was used to obtain the time history curve of soil dynamic response,and estimate the stress route of soil.The Datong—Qinhuangdao Heavy Haul Railway was subjected to dynamic stress field tests where the correctness of the dynamic model was verified and the effects of various train axle loads,speeds,and soil saturation on the three-dimensional dynamic response and stress path of an unsaturated subgrade were investigated.The results show that the influence of train speed is significant on horizontal normal stressesσ_(x) andσ_(y),but minor on vertical normal stressσ_(z) and shear stress τ_(xz).With an increase in train axle load,all dynamic response parameters increase correspondingly.The waveforms of various dynamic response curves alter as the depth changes.The lower the peak values of the curves,the deeper the depth.The moving train load will cause the stress axis of the subgrade soil element to rotate.The stress route gradually decreases from four circles to one circle as the depth increases.This study shows important theoretical value for the design and service performance improvement of heavy-haul railway subgrade structures.

关 键 词：重载铁路 三维动应力 现场测试 理论计算 应力路径 

分 类 号：U211.4[交通运输工程—道路与铁道工程]