超大直径盾构始发井端头复合地层加固施工技术  

Construction technique of strengthening compound stratum at the starting end of super-large-diameter shield tunneling jacking shaft

作　　者：张振 Zhang Zhen(Shield Tunneling Division,Shanghai Tunnel Engineering Co.,Ltd.,Shanghai 200127,China)

机构地区：[1]上海隧道工程有限公司盾构工程分公司,上海200127

出　　处：《工程勘察》2025年第5期43-47,共5页Geotechnical Investigation & Surveying

摘　　要：随着盾构隧道朝着大直径方向发展,超大直径盾构在跨海越江大直径、长距离盾构隧道方面应用越来越多;盾构隧道直径的增大使得端头加固成为了难题。本文以妈湾跨海通道工程海域段盾构隧道始发工程为依托,采用现场施工参数数据结合后期取芯验证的方式,对工作井端头加固方式合理性及安全性展开研究。研究结果表明:三轴搅拌桩在黏土、残积土、全—强风化层中是可以钻进的,且成桩效果较好;在海水水质中,三轴搅拌桩成桩时间尽量在盾构始发前三个月完成,以确保水泥土完全硬化;在砂性地层中,三轴搅拌桩应调整水灰比为0.45;在全—强风化层中,水泥浆沿岩层裂隙劈裂压注,容易造成整体取芯不佳,应降低搅拌桩的钻进速度与提升速度,严格控制每一幅搅拌桩的施工时间。With the increasing diameter of shield tunnels,their use in cross-sea and long-distance projects is becoming more common.The increase in the diameter of shield tunnels has made the end reinforcement a challenging issue.This paper studies the feasibility and safety of end reinforcement in the marine area section of the Mawan Cross-Harbour Tunnel Project.By combining on-site construction parameter data with later coring verification,the study assesses the reasonableness and safety of the reinforcement.The research finds that triaxial mixing piles can be drilled in various soil types,including clay,residual soil,and completely and highly decomposed layers,with a more pronounced effect in seawater.To ensure complete hardening of the cemented soil,the pile formation should be completed three months before the shield launching.In sandy strata,the water-cement ratio should be adjusted appropriately.In completed decomposed layers,cement grout should be pressed along rock cracks to avoid poor coring.Additionally,the drilling and lifting speeds of the mixing pile should be reduced,and the construction time of each pile should be strictly controlled.

关 键 词：盾构隧道 大直径 三轴搅拌 复合地层 端头加固 

分 类 号：TU472[建筑科学—结构工程]