Abstract: The Shenzhen-Zhongshan immersed tunnel project (hereinafter Shenzhong Link) faces significant technical challenges, including high-water pressure, hazardous back-silt issues, long-span structural design, and high construction requirements. To ensure the project′s safety and durability during construction and operation periods, a novel steel-shell concrete combination structure is adopted. For the Shenzhong Link steel-shell concrete immersed tunnel, the techniques of structure selection, cross-sectional design, longitudinal segment division, special structure, and detailed steel-shell structure, as well as the manufacturing, assembling, and transportation techniques for steel-shell, self-compacting concrete-casting technique, and advanced void detection method for steel-shell concrete are introduced. The key techniques for designing, manufacturing, and constructing immersed tunnels are summarized. Additionally, some optimization suggestions are made for the design of the steel-shell concrete shear connector, steel plate connection structure, and concrete void detection method, based on the characteristics of Shenzhong Link.

Key words: Shenzhen-Zhongshan link, steel-shell immersed-tube, design, manufacturing