基于双层梁理论的隧道下穿诱发无砟铁路变形计算方法  

Theoretical Method for Calculating Rail Deformation of Ballastless Railway Caused by Tunnel Undercrossing Based on Dual Beam Model

作　　者：雷鸣 张丙强 刘海 黄志斌 LEI Ming;ZHANG Bingqiang;LIU Hai;HUANG Zhibin(School of Civil Engineering,Changsha University,Changsha 410022,China;School of Civil Engineering,Fujian University of Technology,Fuzhou 350118,China;Fujian Railway Construction Co.,Ltd.,of China Railway 24th Bureau Group,Fuzhou 350013,China)

机构地区：[1]长沙学院土木工程学院,湖南长沙410022 [2]福建理工大学土木工程学院,福建福州350118 [3]中铁二十四局集团福建铁路建设有限公司,福建福州350013

出　　处：《西南交通大学学报》2024年第3期646-652,669,共8页Journal of Southwest Jiaotong University

基　　金：福建省自然科学基金(2020J01882,2023J01344);湖南省教育厅重点项目(19A044)。

摘　　要：为研究隧道下穿无砟铁路轨道时板底部脱空对轨道变形的影响,提出一种改进的隧道下穿引起无砟铁路变形的计算方法.首先,将无砟铁路轨道结构简化为双层地基梁模型,建立隧道下穿施工引起无砟铁路变形的控制方程;然后,将无砟铁路分为中间脱空段和两端接地段共三部分,推导隧道下穿施工诱发无砟铁路变形的计算式,对比路基不均匀沉降引起无砟轨道变形的理论计算值与数值模拟结果,验证了理论计算方法的正确性;最后,探讨了新建隧道埋深、隧道下穿施工引起周围地层的损失率,以及既有铁路与隧道间的水平夹角对无砟铁路轨道变形的影响.研究结果表明:当隧道从铁路下方6 m处垂直穿越既有铁路时,轨道中点变形将达到最大值;隧道施工引起周围地层损失率从0.25%增大到2.50%时,轨道中点变形和轨道板底部脱空区宽度将分别增大4.0倍和2.2倍.To analyze the effect of a void under the track slab on the rail deformation of a ballastless railway caused by tunnel undercrossing,an improved calculation method was proposed to predicate the tunnel undercrossing-induced rail deformation of the ballastless railway.Firstly,the rail of the ballastless railway was simplified as a dual subgrade beam model,and the governing equation was established for the rail deformation of ballastless railway caused by tunnel undercrossing.Then,the ballastless railway was divided into three parts including the middle section above a void and the two sections connecting with the subgrade,and the formulas for the rail deformation of the ballastless railway caused by tunnel undercrossing were derived.The proposed theoretical calculation method was verified by comparing the theoretically calculated and numerically simulated results of rail deformation of the ballastless railway caused by uneven settlement of the subgrade.Finally,the influences of parameters on the rail deformation of the ballastless railway were discussed,including the burial depth of the new tunnel,the ground loss rate caused by tunnel undercrossing construction,and the intersection angle between the railway and the tunnel.The results show that when the undercrossing tunnel is 6 m below the railway,the deformation at the midpoint of the rail reaches the maximum.When the ground loss rate caused by tunnel undercrossing construction increases from 0.25%to 2.50%,the deformation at the midpoint of the rail and the width of the void under the track slab increase by 4.0 and 2.2 times,respectively.

关 键 词：轨道变形 隧道下穿 双层梁模型 WINKLER地基 理论方法 

分 类 号：U211.1[交通运输工程—道路与铁道工程]