双线盾构隧道开挖对临近桥桩的影响规律研究  

Analysis of influence of double-line shield tunnel excavation on adjacent bridge piles

作　　者：梁涵[1] LIANG Han(China Railway First Survey and Design Institute Group Co.,Ltd.,Xi'an 710043,Shaanxi,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,陕西西安710043

出　　处：《建筑科学与工程学报》2024年第2期134-142,共9页Journal of Architecture and Civil Engineering

基　　金：中铁第一勘察设计院集团有限公司科技研究开发计划项目(19-42)。

摘　　要：为了研究盾构隧道近距侧穿既有桥桩产生的影响,基于呼和浩特地铁1号线侧穿鼓楼立交桥桩工程实例,借助ABAQUS进行数值建模,采用Mohr-Coulomb弹塑性理论,对桩长、桩径、隧道埋深和桩顶荷载等影响因素进行了对比分析。结果表明:在隧道开挖土体扰动的影响下,随着桩长、桩径和桩顶荷载的增加,3根桩的水平位移都逐渐降低,Ⅰ号桩和Ⅲ号桩的桩身弯矩都逐渐增加;因Ⅱ号桩位于双线隧道之间,在开挖过程中桩身弯矩受到左右两线隧道开挖产生的叠加效应而相互抵消,使其桩身弯矩不呈规律性变化;随着隧道埋深的增加,3根桩的水平位移均未产生规律性变化,但桩身弯矩显著增加,且桩身弯矩最大值位于隧道埋深范围内;当隧道埋深较浅时,其开挖影响范围较小,对临近桩的影响也较小;注浆加固可有效控制隧道开挖过程中桩基的水平位移和地面沉降,但桩基水平位移的控制效果随着盾构隧道与桩基间净距的减小而逐渐降低。In order to study the influence of shield tunnel crossing the existing bridge pile closely,based on the engineering example of Hohhot metro line 1 crossing the drum tower overpass pile,the numerical model was established by ABAQUS,and the Mohr-Coulomb elastic-plastic theory was used to compare and analyze the influence factors of pile length,pile diameter,tunnel depth and pile top load.The results show that under the influence of soil disturbance in tunnel excavation,with the increase of pile length,pile diameter and pile top load,the horizontal displacement of the three piles are gradually reduced,and the bending moment of pile I and pile III are gradually increased.Since the pile II is located between the two tunnels,the bending moment of the pile is offset by the superposition effect of the left and right tunnels during the excavation,so that the bending moment of the pile does not change regularly.With the increase of the buried depth of the tunnel,the horizontal displacements of the three piles do not change regularly,but the bending moment of the piles increase significantly,and the maximum bending moment of the piles is within the range of the buried depth of the tunnel.When the buried depth of the tunnel is shallow,the excavation influence range is small,and the influence on the adjacent piles is small.Grouting reinforcement can effectively control the horizontal displacement of pile foundation and ground subsidence during tunnel excavation,but the control effect of horizontal displacement of pile foundation decreases with the decrease of net distance between shield tunnel and pile foundation.

关 键 词：盾构隧道 侧穿桩基 影响因素 数值模拟 

分 类 号：TU311.2[建筑科学—结构工程]