穿黄隧洞大型超深竖井结构加固与防水设计  

Structural reinforcement and waterproof design for extra-depth shaft well of tunnel crossing Yellow River

作　　者：谢向荣 石裕 符志远 

机构地区：[1]长江水利委员会长江勘测规划设计研究院,湖北武汉430010

出　　处：《人民长江》2011年第8期21-30,共10页Yangtze River

基　　金："十一五"国家科技支撑计划项目"复杂地质条件下穿黄隧洞工程关键技术研究"(2006BAB04A11)

摘　　要：穿黄隧洞采用盾构法施工。其南岸工作井位于主河床,北岸竖井位于低漫滩,工程施工直接受黄河来水影响。工作井采用逆作法施工,以地下连续墙作为基坑开挖时的支挡结构。其中北岸工作井为盾构始发井,上部地层为粉细砂,地下水位高,地下连续墙深76.6 m,井内挖深50.5 m,为超深竖井。地下连续墙施工时存在槽孔坍塌、槽段开衩、槽段间夹泥等问题;在内衬施工过程中,地下连续墙存在抗踢脚稳定、槽段间漏水等问题;工作井进出洞部位外侧水头高,地层为铁板砂,盾构进出洞封水问题突出;地下连续墙与基岩之间为透水中砂层,基坑下部防渗依托层厚度不足,工作井在盾构机施工期抗浮稳定难以满足要求;内衬在盾构进出洞处结构受力复杂。为此,在对工作竖井展开全面的结构加固与防水研究后,提出了地下连续墙下接帷幕、墙外灰浆墙、井底适时加固、槽段间辅助防渗、局部槽段槽壁加固、洞口加固、水封等一整套综合措施,为工程成功建成发挥了重要作用。The tunnel crossing Yellow River is constructed with shield machine method.The south-bank shaft well is located in the main riverbed and the north one is in the lower floodplain.The south-bank shaft well is built with inverse construction method and underground diaphragm wall is designed for retaining structure in foundation pit excavation.The north-bank shaft well is the starting well for shield machine.For the north-bank shaft well,its upper layer is of fine sediment with a high underground water level,the underground diaphragm wall is 76.6m in depth and the internal excavation depth of the shaft well is 50.5m,which is a extra-depth shaft well.In the construction,there exist the following problems such as trough collapsing,slitting,and mud mixing between them and so on;wall foot instability,leakage between trough sections of underground diaphragm in the construction of internal lining;high outside water head,hard sediment of the strata,water-sealing at the starting and ending locations;due to the pervious middle-size sand layer between underground diaphragm wall and foundation rock,insufficient thickness of lower support layer of pit and anti-buoyancy capacity of shaft well,which can not meet the design requirement in shield machine construction;complicated force bearing of internal lining at entrance and exit locations.Therefore,an overall research on structural reinforcement and water-proof for the shaft well is conducted and the corresponding comprehensive measures are put forward,such as underground diaphragm wall connecting curtain,mortar wall outside the shaft wall,timely reinforcement for well bottom,auxiliary seepage prevention between troughs,reinforcement for partial trough walls,reinforcement for entrance and exit locations,water-sealing and so on.These measures play an important role in the successful completion of construction.

关 键 词：超深竖井 地下连续墙 结构加固 防水设计 南水北调中线工程 

分 类 号：TV67[水利工程—水利水电工程]