Virtual Trial Assembly of Welded Box Type Steel Structures Assisted by Terrestrial Laser Scanning

Abstract Abstract：During physical trial assembly (PTA), conventional measurement methods such as total stations have limited capability in capturing continuous geometric deviations and rely heavily on manual operation. In addition, the PTA process requires substantial resources. This study develops a virtual trial assembly (VTA) method for welded box type steel components using high accuracy point cloud data acquired via terrestrial laser scanning (TLS). The method establishes a segmentation framework operating at the component scale, integrating multi-scale filtering with clustering to reliably isolate individual components. A proxy bounding box is further introduced to identify assembly regions and support subsequent feature extraction. To meet the engineering requirement for reserved welding gaps in welded assemblies, a VTA strategy based on a virtual control plane is developed. Case studies based on steel box girder components and consecutive arch rib segments are conducted to validate the feasibility of the proposed TLS based VTA method for steel bridge construction.