适用于高水压的顶管进出洞止水装置研究

Study on Sealing Devices of Pipe Jacking for Entering and Exiting Tunnel under High Groundwater Pressure

顶管是一种利用掘进机头挖掘隧道，利用千斤顶顶推管道进入设计位置的施工方法。随着人类活动范围的不断扩大，顶管工程逐渐向大埋深的特点发展。由于此类隧洞大部分位于水位线一下，在顶管进出洞（即工作井）过程中，如果未设置洞口密封装置或者洞口密封装置设置达不到工程要求，就会造成减阻泥浆流失、顶力上升，乃至地下水涌入工作井，导致施工环境恶化。本文在总结现有顶管进出洞止水装置的基础上，利用一套大型顶管密封试验装置，对港珠澳大桥珠海连接线拱北隧道暗挖段顶管施工所采用的出洞止水装置和套管接收装置进行了室内密封试验。验证了此套设计适用于高水压的顶管进出洞止水装置的可靠性，总结了施工过程中的应用情况。为今后的类似工程提供了很好的借鉴。

As a method to lay pipes into designed underground place, pipe jacking usually uses heading machine to tunnel, following by latter pipes jacked by oil cylinder. As the range of motion of human expanding depth of pipe jacking increases, the lack of sealing devices or the failure of it may result in loss of slurry, increasing of thrust force and injection of groundwater into working shaft. This article, based on summary of existing sealing devices for entering and leaving tunnel, proves dependability of sealing device for entering tunnel and casing receiving device for leaving tunnel which are both used on pipe jacking construction of Gongbei Tunnel of HK-Zhuhai-Macao Bridge through laboratory test. The application of these devices is also presented. The devices and practical experience can be referred in similar engineerinz.