摘要
以某大直径桥墩基坑施工为例,分析桥墩施工对邻近区间隧道变形与结构强度的影响。结果表明:当桥墩基坑开挖至基底时,区间隧道的水平位移急剧增大;当桥墩承台基坑处于回筑阶段时,区间隧道水平位移出现微量回弹。随着桥墩承台基坑开挖的推进,相邻区间隧道的竖向位移(上浮)持续增大,当开挖至基底时,竖向位移急剧增大并达到最大值;当桥墩承台基坑处于回筑阶段时,相邻区间隧道的竖向位移急剧回弹(下沉),表明承台基坑开挖卸载与回筑加载对相邻区间隧道的竖向变形影响显著。桥梁上部结构施工对相邻区间隧道的水平位移影响较小,但对竖向位移影响明显。基于桥墩全工况施工分析,研究成果可为类似工程提供参考。
Taking the foundation pit construction of a large-diameter bridge pier as an example,the research analyzes the influence of the pier construction on the deformation and strength of the adjacent section tunnel.The research finds that the horizontal displacement of the section tunnel increases sharply when the pier is excavated to the base;when the foundation pit of the pier cap is in the backfill stage,the horizontal displacement shows slight rebound.For the vertical displacement of the section tunnel,the vertical uplift displacement(floating)of the adjacent section tunnel increases continuously with the advance of the foundation pit excavation of the pier cap.When the excavation reaches the base,the vertical displacement increases sharply and reaches the maximum value;when the pile cap foundation pit of the bridge pier is in the backfill stage,the vertical displacement of the adjacent section tunnel rebounds sharply(sinks),indicating that the unloading and backfill loading of the pile cap foundation pit excavation have a strong impact on the vertical deformation of the adjacent section tunnel.During the construction of bridge superstructure,the horizontal displacement of adjacent section tunnels is basically not affected;the vertical displacement of adjacent section tunnels is more significant.Based on the construction analysis of bridge pier under all working conditions,the research results can provide reference for similar projects.
作者
李晓雷
LI Xiaoei(China Railway 18th Bureau Group Fifth Engineering Co.,Ltd.,Tianjin 300450,China)
出处
《现代交通技术》
2025年第5期35-39,52,共6页
Modern Transportation Technology
关键词
桥墩承台
区间隧道
基坑开挖
回筑
桥梁上部结构
pier cap
section tunnel
foundation pit excavation
backfill
bridge superstructure
