Automatic Detection of Delamination on Tunnel Lining Surfaces from Laser 3D Point Cloud Data by 3D Features and Support Vector Machine

 A completely automatic and accurate detection algorithm for the delamination on tunnel concrete lining surfaces from laser 3D point cloud data is proposed. A Mobile Mapping System (MMS), which mounts laser sensors and a positioning system, is utilized to measure the geometry of tunnel lining surfaces highspeed. The proposed algorithm consists of 4 steps: removal of tunnel profile components, detection of peaks of anomalies, localization of anomaly areas, classification of delamination and appendages. On tunnel linings, there are many appendages such as cables, lights, signs, and water guides to mask the features of delamination. In the article, a novel 3D feature was introduced to realize the accurate classification. An automatic SVM algorithm was developed using real tunnel lining data and manual inspection results, showing an accurate delamination map.