BIM-Integrated Parametric Modelling of Existing Box Girder Bridges Using Point Cloud Data

Bridge digitalization increasingly relies on scan-to-BIM techniques to generate accurate as-built models from point-cloud data; however, existing approaches mainly focus on geometric reconstruction or standardized model export, providing limited support for engineer-controlled and editable infrastructure modelling workflows. This paper presents a parametric scan-to-BIM framework for existing box-girder bridges that combines automated geometric extraction with interactive modelling and real-time BIM generation. The proposed workflow starts from drone-based photogrammetric point-clouds and reconstructs bridge components through parametric modelling, where cross-sectional geometry and longitudinal arrangement are controlled by structured parameters stored in a spreadsheet environment. A live synchronization mechanism enables real-time transfer of the parametric model to the BIM platform, while a dedicated user interface allows non-expert users to generate and verify bridge models through guided input of engineering parameters. Unlike previous reconstruction-oriented methods, the approach prioritizes controllable modelling, editability, and practical usability, enabling rapid generation of information-rich as-built models suitable for rehabilitation and asset management applications. The results demonstrate reduced manual modelling effort, improved consistency, and enhanced adaptability compared to traditional modelling workflows, supporting the integration of existing bridges into digital-twin-oriented infrastructure management processes.