The Zhangjiawan Depot entry/exit line section is 130 meters long, 21-33 meters wide, and 11-14 meters deep, located 650 meters in a straight line from the Yangtze River. It serves as the shield launching shaft for the first section of Phase III of Wuhan Metro Line 11.


　　Construction Technology

　　The retaining structure of the entry/exit line adopts a system of bored cast-in-place piles + concrete struts + steel struts, constructed using the open-cut method. The main structure is a one-story underground reinforced concrete rectangular frame structure with a fully enveloping waterproof layer. The maximum height of the formwork support for the main structure of the entry/exit line section is 9.32 m, using ringlock scaffolding. The side wall formwork adopts integral large steel forms, which offer the advantages of fast turnover and smooth, flat concrete appearance. The construction of the foundation pit waterproof curtain adopted the TRD process (continuous cement-soil mixing wall) for the first time in Wuhan Metro construction, and as the first demonstration project of this process, it has been visited by Wuhan Metro Group for observation on multiple occasions.


　　Construction Progress

　　During construction, the project successively withstood the tests of the COVID-19 pandemic and flood-season emergencies, and overcame difficulties such as poor soil quality in foundation pit excavation, restricted earthwork transport, and high difficulty in structural waterproofing construction. The project department actively optimized the construction organization plan and worked two shifts around the clock to rush progress. On December 21, 2020, the project department ultimately completed the work 7 days ahead of the original schedule, laying a solid foundation for the shield launching of the first section of Phase III of Line 11. At the same time, the successive early completion of key milestone targets greatly boosted the morale of frontline builders and demonstrated the company's strong contract performance and production organization capabilities.