English：

Aiming at the problems of low construction accuracy and long⁃term waterproof difficulty ofprefabricated diaphragm wall joints in urban subway foundation excavation engineering, based on theentrance and exit project of Zhoucun Station of Qingdao Metro, the technical scheme of prefabricatedcast⁃in⁃place interphase diaphragm wall is proposed. The lightweight structure form of the prefabricatedwall, the vertical and horizontal connection structure of the segment and the composite waterprooftechnology were studied, and a complete construction technology system from factory prefabrication to on⁃site mechanized hoisting was constructed. The results show that with the increase of excavation depth, thedisplacement and influence range of soil behind the wall increase, and the minimum influence range isabout 3 times the excavation depth. The scheme effectively avoids the construction and waterproof risk ofdirect splicing of precast wall, and improves the engineering safety and construction efficiency.