Concrete bridges 3D photogrammetry modelling for crack localisation and virtual reality visualisation

Cracks are common defects in concrete structures and could lead to structural failure. This study provides a solution to support Structural Health Monitoring of concrete bridges from 2D images to a 3D model and then to Virtual Reality (VR) visualisation. To accomplish this, two concrete bridges in the Mediterranean Sea region were inspected, and image data were collected. This data was subsequently annotated manually for cracks through the VGG tool and then analysed via the 3DF Zephyr software. From a Sparse point cloud to a Dense point cloud and then a 3D mesh, all were smoothly constructed using the mentioned software, with better visualisation of the annotated cracks in the final 3D model of the bridges. In the end, the 3D model .ply file was converted to .glb format, which is supported by the majority of the VR glasses apps, making the virtual inspection possible through mobile devices.