Application of Semi-closed Curtain of Diaphragm Wall in Deep Foundation Pit Adjacent to Subway

In the area of first terrace of the Yangtze River, the design of deep foundation pit is faced with problems such as poor soil quality and abundant groundwater. The design of foundation pit adjacent to the subway is often provided with a vertical water-stopping curtain. A foundation pit is close to the Fanhu Station of Wuhan Metro Line 2. The semi-closed curtain and semi-suspended diaphragm wall was used as a vertical retaining structure and also as a water-stopping curtain. Two layers of concrete ring supports were set up, supplemented by dewatering in the foundation pit. During the operation of the foundation pit, there was no adverse impact on the surrounding roads, subways and other structures. Compared with the closed curtain (or diaphragm wall), the economic benefits are significant, which can be used as a reference for similar projects.