Abstract: To improve digital design quality and efficiency for immersed-tube tunnels, a combined approach of standard formulation and software programming is used to develop a digital design system for the civil structure of immersed-tube tunnels. First, the authors summarize and analyze practical experiences in immersed-tube tunnel design, distilling the critical requirements for digital design processes, leading to the formulation and establishment of the Standard for Delivery of Immersed Tunnel Digital Design. Subsequently, utilizing this standard as a reference, the authors proceed to develop a digital design system for the civil structure of immersed-tube tunnels, which is tested and validated through implementation in multiple real-world engineering projects. According to the digital design process, the digital design system for the civil structure of immersed-tube tunnels is divided into three modules: digital design module, calculation and analysis module, and information addition module. The digital design module analyzes the design parameters entered by users and automatically generates models, drawings, and engineering quantity tables. The calculation and analysis module has built-in formula verification functions such as anti-floating and freeboard calculation, and establishes a data linkage relationship between the design parameters in the digital design module and the existing finite element calculation software for immersed-tube tunnels, thereby improving calculation efficiency. The information addition module integrates the classification coding and information addition rules of the model into the software, achieving rapid addition of classification coding and information.

Key words: immersed-tube tunnel, civil structure, digital design