复杂地层超深地下连续墙设计与施工关键技术

Key Technologies for Design and Construction of Ultra⁃deep Diaphragm Wall in Complex Strata

以上海软土地区某挖深达45.5m的矩形超深基坑工程为依托,针对深度约90m的超深地下连续墙的设计和施工关键技术展开了系统研究。提出了适用于超深基坑工程的墙体分幅设计、止水措施、混凝土配合比、钢筋配置、垂直度要求等一系列设计参数。正式施工前进行了复杂地层的成槽试验及首件施工验收,确定其施工能力、施工工效以及施工参数,并针对超深地下连续墙容易出现的施工质量通病提出了系统的施工控制措施。在此基础之上完成了该工程超深地下连续墙的正式施工,墙体质量的超声波检测及开挖验证结果均达到设计要求,坑外地下水监测数据验证了悬挂帷幕的承压水控制效果,顺利通过了基坑开挖和结构回筑的服役过程。

Based on a rectangular ultra⁃deep foundation excavation project with a depth of 45.5m in a soft soil area in Shanghai,the key technologies of the design and construction of an ultra⁃deep diaphragm wall with a depth of about 90m are systematically studied.A series of design parameters,such as wall framing design,water stop measures,concrete mix ratio,steel bar configuration and verticality requirements suitable for ultra⁃deep foundation excavation engineering,are proposed.Before the formal construction,the grooving test of complex strata and the first construction acceptance were carried out to determine the construction capacity,construction efficiency and construction parameters,and systematic construction control measures were put forward for the common construction quality problems that are prone to occurrence in the ultra⁃deep underground continuous wall.On this basis,the formal construction of the ultra⁃deep underground continuous wall of the project was completed.The ultrasonic detection and excavation verification results of the wall quality meet the design requirements.The groundwater monitoring data outside the pit have verified the control effect of the confined water of the suspended curtain and have successfully passed the service process of foundation excavation and structural reconstruction.