基坑开挖方式对既有下卧地铁隧道变形的影响研究

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【中图分类号】：TU753 【文献标志码】：A 【文章编号】：1008-3197（2025）04-21-04

【DOI编码】：10.3969/j.issn.1008-3197.2025.04.006

The Influence of Foundation Pit Excavation Methods on Deformation of Existing Underlying Subway Tunnel

LI Yongbo¹， ZHANGJiawei²，ZHAO Xin²，XU Shaoyun1

（1.JiangsuClegolooa；.iaialEggi&s Co.，Ltd.，Tianjin300392，China）

【Abstract】：To investigate the influenceof foundation pit excavation methods on the deformationof existing underlying subway tunnels，a three-dimensional strata-tunnel-foundation pit analysis model was established using the MIDAS GTS NX finite element software，focusing on a proposed deep and large foundation pit excavation directly above a shield tunnel in Tianjin.By comparing two excavation schemes-conventional excavation without ground reinforcement and excavation with depth zoning combined with portal-type reinforcement using cement-mixing piles—the study analyzes the effects offoundationpit excavation onthe horizontal and vertical deformationaswellaslongitudinal differential setlementof the tunnel.Theresults indicate that conventional excavation without reinforcement caused tunnel deformations exceeding control limits，while the reinforcement scheme effectivelled controls tunnel deformations，ensuring compliance with requirements.

【Key words】： shield tunnel; foundation pit excavation； stratum reinforcement

随着投入运营的城市轨道交通线路增多，在既有隧道结构附近施工的基坑工程案例亦逐渐增多，由基坑开挖引起的土体卸载对隧道结构和地铁运营安全的影响越来越引起人们重视[1-3]。（剩余3187字）