Integrated data model for bridges with 3D geometry and maintenance information

The Japanese government has been promoting construction information modeling initiatives, following the example of building information modeling, which has been widely adopted in the construction sector of Western countries. However, progress in preparing and utilizing 3D data for existing structures, which are primarily subject to maintenance and management, has been limited. Previous studies have proposed methods to automatically generate 3D models by capturing the three-dimensional structure and dimensions of target objects from point clouds obtained through laser scanners. However, these studies do not address the interoperability of various data, and international standard data schemas such as Industry Foundation Classes (IFC) by the International Alliance of Interoperability and CityGML by the Open Geospatial Consortium (OGC) do not define schemas that encompass maintenance and management information, such as inspection results. Therefore, this study proposes a one-source, multi-use data schema capable of comprehensively managing both structural and maintenance information for bridges. The proposed data schema complies with international standards by integrating IFC-Bridge into CityGML, a standard developed by the geospatial information standardization organization OGC. A validation experiment was conducted using drawings, inspection records, and point clouds of bridges in Shizuoka City, demonstrating that the schema can be applied to 20 bridges of four types for three different use cases.