大型盾构隧道火灾高温特性及力学行为研究  

Research on Thermal Properties and Mechanical Behaviors of Large Shield Tunnel in Fire

作　　者：章庭瑞 ZHANG Tingrui(Shanghai Municipal Engineering Design Institute(Group)Co.,Ltd.,Shanghai 200092)

机构地区：[1]上海市政工程设计研究总院(集团)有限公司,上海200092

出　　处：《现代隧道技术》2022年第5期202-211,共10页Modern Tunnelling Technology

摘　　要：由于空间环境封闭,隧道火灾常具有升温快、持续时间长、温度分布不均匀等特点,极易造成隧道衬砌受热损伤破坏,导致结构力学性能大幅衰减,严重影响隧道运营的安全性及可靠性。针对该问题,以某大直径盾构隧道工程为背景,建立了三维精细化有限元模型,研究了不同火灾场景下隧道内温度场分布规律及结构变形、内力随时间发展规律。结果表明:(1)受到热边界条件的影响,火灾发生后隧道内温度场分布出现明显的分区现象;(2)火灾工况下衬砌圆环的变形模式由荷载效应及热膨胀效应共同决定,两种因素的作用效果受火灾规模及火灾时间的影响;(3)火源影响区域内各管片内外两侧受力较大,衬砌内侧钢筋对结构受力贡献较大,但随着火灾发展,管片及钢筋的应力分布均出现显著变化。Due to the closed space,tunnel fires have the characteristics of rapid temperature rise,long duration,uneven temperature distribution and so on.It is very easy to cause thermal damage to the tunnel lining,resulting in significant attenuation of structural mechanical properties,which seriously affects the safety and reliability of tunnel operation.In order to solve this problem,a three-dimensional finite element model is established based on a large diameter shield tunnel project,and the temperature field distribution,structural deformation and internal force under different fire scenarios are studied.The study concluded that:(1)Under the influence of thermal boundary conditions,the distribution of temperature field in tunnel appears obvious partition phenomenon in fire;(2)The deformation mode of the lining ring in fire is determined by load effect and thermal expansion effect,and the two factors are affected by fire scale and fire time;(3)In the area affected by the fire source,the stress on both sides of each segment is large,and the inner rebar makes a great contribution to the mechanical performance of structure.However,with the development of fire,the stress distribution of segments and rebars changes significantly.

关 键 词：大直径 盾构隧道 火灾 热力耦合行为 有限元分析 

分 类 号：U452[建筑科学—桥梁与隧道工程]