盾构隧道下穿既有隧道保护方案优化分析  

Optimization Analysis of Protection Schemes for Shield Tunnel Undercrossing Existing Tunnel

作　　者：龚云强 张委定 杨巧玲 GONG Yunqiang;ZHANG Weiding;YANG Qiaoling(North China Municipal Engineering Design and Research Institute Co.,Ltd.Tianjin 300074,China;Tianjin Municipal Engineering Design and Research Institute Co.,Ltd.Tianjin 300051,China;Tianjin Tianshi College Tianjin 301700,China)

机构地区：[1]中国市政工程华北设计研究总院有限公司,天津300074 [2]天津市政工程设计研究总院有限公司,天津300051 [3]天津天狮学院,天津301700

出　　处：《广东土木与建筑》2025年第1期108-112,共5页Guangdong Architecture Civil Engineering

摘　　要：盾构下穿既有隧道会产生明显的扰动影响,存在较大施工风险,需要进行控制保护。依托某近距离下穿既有隧道的盾构隧道工程,建立了MJS水平加固、管棚注浆加固、地面袖阀管注浆加固3种方案的三维有限元模型,分析了不同加固方案下既有隧道的水平位移、竖向位移变化特征,并从变形控制、工法缺点、可实施性、费用方面进行了比较分析,确定了最优加固方案。研究结果表明:既有隧道以竖向位移为主,是变形控制关键指标;MJS水平加固对既有隧道位移控制效果最有利,地面袖阀管注浆加固效果最差;综合多方面因素,管棚注浆加固为最优保护方案;加固处理后土体强度得到改善,右线盾构隧道施工对既有隧道最大位移量和位置影响不大;双线开挖面距离在2.5倍洞径以上,施工扰动性可一定程度降低。结论可为相似下穿工程提供借鉴与参考。The construction of shield tunnel has an obvious effect on the upper tunnel.There are significant construction risks and control and protection should be carried.Based on one shield tunnel undercrossing the existing tunnel,three-dimensional FEM models of three reinforcement schemes,which are MJS horizontal reinforcement,pipe-shed grouting reinforcement and ground sleeve valve pipe grouting reinforcement,are built.The horizontal and vertical displacement characteristics of the existing tunnels under three reinforcement schemes are analysed in detail.And a comparative analysis was conducted from the aspects of deformation control,construction method shortcomings,feasibility,and engineering costs to determine the optimal reinforcement scheme.Some conclusions have been drawn.Firstly,the displacement of existing tunnels is mainly vertical displacement,which is the key index for tunnel deformation control.Secondly,displacement control of existing tunnels,the scheme of MJS horizontal reinforcement is the best and ground sleeve valve pipe grouting reinforcement has the worst effect.Thirdly,based on four factors,the scheme of pipe-shed grouting reinforcement.Fourth,the soil strength has been improved after reinforcement treatment and the of the right tunnel construction has little effect on the size and position of maximum displacement.Finally,with the distance between the excavation faces of double tracks is more than 2.5 times the tunnel diameter,the construction disturbance can be reduced to a certain extent.The conclusion can provide reference for similar undercrossing project.

关 键 词：新建隧道 既有隧道 加固 MJS水平加固 管棚 袖阀管 

分 类 号：U459.3[建筑科学—桥梁与隧道工程]