Abstract: Traditional three-dimensional (3D) forward design for shield tunnels faces challenges such as the disconnect between geological and structural models, low modeling and simulation efficiency, and significant data loss across systems. Thus, the authors propose a 3D stratigraphic modeling method that utilizes automated stratigraphic sequence definition and sub-borehole recursion to enable differentiated geological models for different tunnel regions. This approach includes a coupling method for aligning 3D geological and structural tunnel models through Boolean operations and virtual borehole probes, alongside methods for automated extraction of geometric boundaries and finite element mesh reconstruction. A twodimensional(2D) automatic mapping process based on 3D refined geometrical models and contour picking is also introduced. The developed unified platform integrates these methods into a comprehensive shield tunnel 3D parametric design system, termed FDP-ST3D. FDP-ST3D supports 3D geological modeling, structural design, numerical analysis, and automated drawing. Applied successfully in projects including the Jinan metro line S1, the Suzhou rail transit line S1, the shield section of Shenzhen Mawan cross-sea tunnel, and the Sutong GIL utility tunnel, FDP-ST3D demonstrates high data transfer accuracy and reusability, reducing 2D tube sheet drawing time to only 15 min, which significantly improves the design efficiency and accuracy compared with the manual work.

Key words:

shield tunnel segment, three-dimensional parametric, geologic model, numerical analysis, two-dimensional drawing