Laser Scanning-Aided Virtual Trial Assembly and Assembly Conflict Detection of Welded Box-Type Steel Arch Ribs

Physical trial assembly (PTA) of large-scale welded steel structures under complex field conditions still relies on conventional measurement methods such as total stations, making it difficult to continuously capture the boundaries of assembly end-faces and analyze assembly deviations. To address this issue, this study proposes a VTA method based on point cloud data for box-section steel arch ribs, in which end-face boundaries and assembly corner points are extracted to quantitatively evaluate the assembly feasibility between adjacent segments. Based on the extracted assembly features, a VTA framework is further established to perform virtual reconstruction of the spatial assembly poses of welded steel structures and validate structural alignment consistency. Furthermore, the proposed method is validated through an engineering case study. The results demonstrate that the proposed framework can effectively reconstruct the spatial assembly poses of welded box-section steel arch ribs, while enabling quantitative assessment of assembly compatibility and identification of assembly conflicts and weld gap anomalies. Compared with conventional total station-based PTA, the proposed method reduces overall resource consumption and assembly time by approximately 90% and 60%, respectively, demonstrating strong potential for virtual engineering of large-scale steel structures.