上海长江隧道工程盾构水中进洞施工技术

Shield Break-in in Water Construction Technology of Shanghai Yangtze River Tunnel Construction

上海长江隧道工程盾构水中进洞段的覆土最薄处为6.187m,属于超薄覆土盾构施工,给地面沉降控制增加了难度,同时极有可能出现隧道"上浮"现象;由于正面压力的减少,易造成管片之间的松动。介绍了该隧道工程所采用的盾构水中进洞的过程,分析并探索了为防止地下水进入工作井,采用井点降水、水中进洞以及洞门封堵等保证盾构进洞安全的技术措施。

The minimum depth of soil covering at the shield break-in section of Shanghai Yangtze River Tunnel is 6.187m.The extra-thin embedment increases the shield construction difficulty:difficult to control the ground settlement and resulting in tunnel 'floating',and resulting in the looseness between segments due to the pressure decrease at the shield face.The paper describes the process of shield break-in in water and analyzes the technical measures which ensured the shield break-in safely.These measures include dewatering,break-in in water and blockage of soft-eye.