冻融循环作用对隧道浅埋段的稳定性影响研究  

Study on the Stability Influence of Shallow Buried Section of the Tunnel Under Freeze-Thaw Cycle Effect

作　　者：高勇 GAO Yong(China Railway 19th Bureau Group 6th Engineering Co.Ltd.,Wuxi Jiangsu 214028,China)

机构地区：[1]中铁十九局集团第六工程有限公司,江苏无锡214028

出　　处：《铁道建筑技术》2025年第2期162-164,192,共4页Railway Construction Technology

基　　金：中铁十九局集团有限公司科技研究开发项目(23-A03)。

摘　　要：以四川省红原2号隧道为研究对象,采用COMSOL Multiphysics有限元软件对冻融循环作用对隧道浅埋段的稳定性影响进行研究。结果显示:隧道浅埋段在冻融循环期间,外界环境温度的波动直接导致其表层温度发生显著变化,整个过程最大冻结深度达2.98 m;冻结过程中,土体产生冻胀力使隧道浅埋段发生冻胀变形,整体稳定性有增加趋势。通过有限元强度折减法计算常温及融化条件下隧道浅埋段安全稳定系数,前者明显高于后者;冻结过程中,随冻结深度增加,安全稳定系数随之变大,而融化过程随融化深度增加,安全稳定系数逐渐减小。对隧道浅埋段地表沉降进行自动化监测,发现隧道中线部位测点沉降变化大,中线两侧测点沉降变化幅度逐渐减小,属下穿隧道典型地表沉降变化态势。This article takes the Hongyuan No.2 Tunnel in Sichuan as the research object,and uses COMSOL Mutiphysics finite element software to study the stability influence of the shallow buried section of the tunnel under freeze-thaw cycle effect.The results show that during the freeze-thaw process,the surface temperature of the shallow buried section of the tunnel changes most significantly with the change of external environmental temperature,and the maximum freezing depth is 2.98 m throughout the entire process.During the freezing process,the soil generates frost heave force,causing frost heave deformation in the shallow buried section of the tunnel,and the overall stability of the shallow buried section of the tunnel tends to increase.The finite element strength reduction method is used to calculate the safety and stability factors of the shallow buried section of the tunnel at room temperature and the melting process.The results show that the former is significantly higher than the latter.In freezing,as the freezing depth increases,the safety and stability coefficient also increases.During melting,as the melting depth increases,the safety and stability coefficient gradually decreases.Automated monitoring of surface settlement in the shallow buried section of the tunnel revealed significant changes in settlement of the measurement points at the tunnel centerline,while the amplitude of settlement changes on both sides of the centerline gradually decreased.This indicates a typical trend of surface settlement changes of underpass tunnels.

关 键 词：冻融循环 隧道浅埋段 稳定性 有限元 变形监测 

分 类 号：U452[建筑科学—桥梁与隧道工程] U456.3[交通运输工程—道路与铁道工程]