Detection and Evaluation of Surface Defects in Bridges by Terrestrial Laser Scanning

Abstract

There are some factors that may cause bridge damages such as the heavy traffic and aggressive environmental conditions. It's important to assess the current status of the bridge to decide on the future steps for rehabilitation. This is due to their impact on landscape where they are built to satisfy the public safety in bridge structural capacity. Despite, the actual bridge techniques demands hard works and lots of subjective visual analysis to decide the state of the bridge. Light Detection and Ranging (LiDAR), also named as Terrestrial Laser Scanning (TLS) is a remote sensing technique that could assist to minimize the variability of results and cover bigger areas, allowing for accurate determination of defects and precise allocation of appropriate funding. The main aim of this research is to develop an easy system to register laser remote sensing data of as-built model, with BrIM (Bridge Information Model) for constructed bridge and compare between them to detect the geometric discrepancies and defects. Mohamed Fawzy Bridge (which is located in Maadi Ring Road, Cairo, Egypt) has been selected as the scenery of this experimental investigation to approve this technique, focused on monitoring structural damages. The scanned data is used to evaluate the status of the selected bridge, its surface defects, vertical clearance, cracks length and width by using the basic software. This data is compared with its corresponding data extracted from the bridge design or drawing. The results of comparison indicate that the used equipment and technique achieved the required tasks with good accuracy.