闹市区复杂环境下大直径盾构小净距下穿运营地铁隧道的应对措施及分析  

Countermeasures and analysis of large diameter shield tunneling under operating subway tunnel with small clear distance in downtown complex environment

作　　者：涂智溢 郭洪雨 孙飞 钟方杰 郑浩龙 张哲 TU Zhiyi;GUO Hongyu;SUN Fei;ZHONG Fangjie;ZHENG Haolong;ZHANG Zhe(Zhejiang Institute of Communications Co.,Ltd.,Hangzhou 310030,Zhejiang,China)

机构地区：[1]浙江数智交院科技股份有限公司,浙江杭州310030

出　　处：《隧道与地下工程灾害防治》2021年第4期75-84,共10页Hazard Control in Tunnelling and Underground Engineering

基　　金：浙江省自然科学基金资助项目(LGF19E08005);浙江省交通运输科技计划资助项目(2021027)。

摘　　要：环城北路-天目山路快速路采用大直径(13.46 m)盾构下穿既有运营地铁隧道,根据既有地铁隧道的长期监测结果,结合上软下硬的复杂地层分布特征及快速路大盾构与地铁隧道的空间位置关系,分析近距离下穿的可行性,提出采用全方位高压喷射(metro jet system,MJS)桩从地面对既有地铁隧道周边地层进行加固、洞内注浆加固等措施,利用FLAC^(3D)有限差分软件对整体应对措施的有效性进行验证,对现场实施及实际监测结果进行分析。实践证明:大直径盾构在上软下硬地层中小净距下穿既有地铁隧道的方案可行,采用MJS地面加固既有隧道周边地层、洞内注浆加固等应对措施有效,可为类似工程施工提供借鉴。The large diameter(13.46 m)shield was used to undercross the existing metro tunnel on the North Ring Road-Tianmu Mountain Expressway.This paper started with the long-term monitoring results of the existing metro tunnel,and combined the distribution characteristics of the upper and soft and hard complex strata and the spatial position relationship between the large shield and the subway tunnel,the feasibility of short distance underpass was analyzed,the MJS(Metro Jet System)columns was used to reinforce the surrounding strata of the existing subway tunnel and grouting reinforcement in the tunnel from the ground was proposed.The effectiveness of the overall response measures was verified by the finite difference software FLAC^(3D),and the field implementation and the actual monitoring results were analyzed.The practice showed that the scheme of large diameter shield tunneling under the existing subway tunnel with small clear distance in the upper soft and lower hard stratum was feasible,and the measures of MJS ground reinforcement of the surrounding stratum of the existing tunnel and grouting reinforcement in the tunnel were effective,which could provide reference for similar engineering construction.

关 键 词：大直径盾构隧道 既有运营地铁隧道 上软下硬复合地层 小净距 应对措施 

分 类 号：U457[建筑科学—桥梁与隧道工程]