Abstract: Currently, most embedded channels in shield tunnel sections are calibrated in a full-ring configuration, thereby ensuring construction stability and convenience. However, this approach may result in excessive vacancies and increased costs. Thus, to reduce the number of embedded channels in shield tunnel segments and minimize project costs, the authors introduce building information modeling (BIM) technology and propose an improved algorithm for a shield tunnel segment layout based on channel optimization. Using BIM as a support platform, an optimization scheme is developed based on the contact network ring and a single channel in the bottom track area, tailored to the project′s actual characteristics. First, considering the contact network layout pattern, the double-channel embedded ring at the top is optimized. Second, the single-ring layout is refined using the minimum fitting error method to determine the optimal position.Third, the single-channel ring is optimized for the bottom track area by establishing rules for segment layout and point selection. This further enhances the layout algorithm. Finally, based on these algorithms, a prototype system is designed to enable the three-dimensional automatic layout of the shield tunnel within the designed interval line and generate an analytical report. This method is applied to specific engineering cases where the output results guide segment production and on-site layout. The application results demonstrate that this method achieves a 14.59% optimization rate for embedded channels in tunnel segments. Moreover, the BIM-based approach generates a three-dimensional visual model of the segments and embedded channels, thereby facilitating a visual review and verification mechanism for the optimization scheme.

Key words: metro, optimization, building information modeling, shield segment, embedded channel