3D Reconstruction from 2D Plans Exemplified by Bridge Structures

Due to increasing traffic on roads and railways, the maintenance of bridges is becoming more and more important. Building Information Modelling (BIM) provides the perfect basis to efficiently plan these maintenance activities. However, for historic bridges, which moreover require intensive maintenance, there is no BIM available. The demand to digitize these bridges is correspondingly high. Further, to the already existing measurement methods (laser scanning, photogrammetry, etc.), a novel workflow for the digitalization of bridges from 2D plans is presented. Based on image processing for corner detection, 3D point cloud reconstruction of parts and fusion of reconstructed parts can be used create a 3D object to scale. The point cloud can serve as a supplement to as-built laser scanning or camera data. The presented method was evaluated based on three bridges over the Dreisam river in Freiburg, Germany.