粉细砂层盾构隧道施工掌子面坍塌及处理研究  

Study on Tunnel Face Collapse and Corresponding Treatment Measures in Shield Tunnelling in Silty-fine Sand Layer

作　　者：李子锋 段保亮 LI Zifeng;DUAN Baoliang(CCC First Highway Engineering Group Co.,Ltd.,Beijing 100024;CCCC Tunnel Engineering Co.,Ltd.,Beijing 100024)

机构地区：[1]中交一公局集团有限公司,北京100024 [2]中交隧道工程局有限公司,北京100024

出　　处：《现代隧道技术》2023年第4期237-245,共9页Modern Tunnelling Technology

摘　　要：泥水盾构机在粉细砂地层掘进时,容易造成掌子面坍塌、刀盘难以脱困以及恢复掘进困难等问题。以南京和燕路过江隧道施工为例,通过对粉细砂层掌子面坍塌过程进行分析,从泥水舱压力控制、泥浆性能调整、掘进参数控制等方面入手,研究超大直径盾构机脱困处理方法,总结有效遏制掌子面坍塌风险,并迅速恢复为正常工况的工程经验。同时结合气泡舱压力平衡原理、掘进参数变化情况等,得出如下结论:(1)泥水盾构机在粉细砂层段掌子面坍塌前掘进参数以排泥密度、切口水压的变化最为明显,排泥密度多次异常增大和切口水压不稳定可作为事故征兆;(2)掌子面发生坍塌后,应遵循“低转速、大贯入度、多次短停”的原则恢复掘进。When the slurry shield machine is used for excavation in the silty-fine sand layer,it is easy to cause problems such as the collapse of tunnel face,difficulty in cutterhead releasing,and difficulty in recovery of advance.Taking the construction of the Heyan Road River Crossing Tunnel in Nanjing as an example,by analyzing the collapse process of tunnel face in the silty-fine sand layer,specifically focusing on such aspects as the control of slurry chamber pressure,slurry performance adjustment,and tunnelling parameter control,the cutterhead releasing method for the extra-large diameter shield machine is studied and the engineering experience of effectively controlling the risk of tunnel face collapse and quickly restoring to the normal working condition is summarized.At the same time,based on the principle of bubble chamber pressure balance and the changes in tunnelling parameters,the following conclusions are drawn:(1)Before the collapse of tunnel face in the silty-fine sand layer,the tunnelling parameters of the slurry shield machine vary most significantly in the discharged slurry density and water pressure at cutting face.Multiple abnormal increases in the discharged slurry density and unstable water pressure at cutting face can serve as accident signs.(2)After the collapse of the tunnel face,the principle of"low rotation speed,large penetration and many times of short-time stops"should be followed to resume tunnelling.

关 键 词：泥水盾构机 粉细砂层 掌子面坍塌 掘进参数 刀盘脱困 处理方法 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]