超大直径盾构下穿河流桥段影响研究  

Reserch on Influence of Super-diameter Shield Tunnel Underpassing the River Bridge

作　　者：姚晓励 刘飞 张伟 Yao Xiaoli;Liu Fei;Zhang Wei(Beijing General Municipal Engineering Design&Research Instituti Co.,Ltd.,100082,China)

机构地区：[1]北京市市政工程设计研究总院有限公司,100082

出　　处：《特种结构》2022年第3期33-39,共7页Special Structures

摘　　要：依托某超大直径泥水平衡盾构下穿河流桥段工程,通过建立三维有限元模型,模拟分析了盾构下穿河流桥段时对地层、既有箱涵以及桥梁桩基的影响。研究发现,盾构掘进引起的最大地层沉降集中在隧道拱顶,最大地表沉降发生在桥梁桩基所处河床面。盾构通过后,桥梁承台及箱涵竖向位移呈现对称性,对称轴为隧道轴线。掘进过程中,桩基最大压应力逐渐增大至盾构通过,最大为8.57MPa,桥梁基础承台最大沉降和最大水平位移分别为7.34mm和2.31mm;箱涵最大压应力为2.52MPa,位于最北端截面_上部,最大沉降为5.55mm,且箱涵两端发生3.38mm的隆起。研究可为类似大直径泥水盾构下穿河流桥段提供借鉴和参考。Based on a super-diameter slurry shield underpassing a river bridge section,a three-dimensional finite element model was established to simulate and analyse the impact of the shield underpassing the river bridge on the ground stratum,existing box culvert and bridge pile foundation.It was found that the maximum ground settlement caused by the shield tunneling concentrated in the tunnel vault,and the max imum surface set-tlement occurred at the river bed surface where the bridge pile foundations were located.After the passage of the shield,the vertical displacement of the bridge bearing platform and box culvert showed symmetry with the axis of symmetry overlaping the tunnel axis.During the tunneling process,the maximum compressive stress in the pile foundation gradually increased until the shield passed,and the maximum was 8.57MPa.The maximum settle-ment and maximum horizontal displacement of the bridge foundation bearing platform were 7.34mm and 2.31mm respectively.The maximum compressive stress in the box culvert was 2.52MPa and located at the up-per part of the northernmost section.the maximum settlement of the box culvert was 5.55mm and a 3.38mm bulge occurred at both ends of the box culvert.The study can provide reference for similar diameter slurry shield underpassing river bridge.

关 键 词：超大直径盾构 河流桥段 三维有限元 既有箱涵桥梁 桩基 

分 类 号：U455.43[建筑科学—桥梁与隧道工程] U443.15[交通运输工程—道路与铁道工程]