Enhancing Reinforced Concrete Bridge Health Monitoring: A Case Study on the Integration of InSAR, GPR, and LiDAR within 3D GIS Environment

Abstract. This work presents a preliminary case study on assessing reinforced concrete pedestrian bridge conditions in A Coruña (Galicia, Spain), employing a novel integration of non-destructive testing (NDT) technologies. The research aims to refine the health monitoring process of pedestrian bridges by adopting a top-down approach, leveraging the data-fusion concept to enhance the analysis of structural defects. A data-fusion methodology that integrates interferometric synthetic aperture radar (InSAR), ground penetrating radar (GPR), and light detection and range (LiDAR) technologies is introduced. Then, the data are visualized within a 3D Geographical Information System (GIS) environment. The MT-InSAR technique is used at the network level to identify bridges requiring detailed inspections. Subsequently, selected bridges undergo thorough examinations using GPR and LiDAR technologies from fieldwork between 2021 and 2023. A comparative analysis of three different LiDAR devices and two GPR setups is conducted to evaluate their effectiveness in capturing detailed structural data. The study also explores the integration challenges and solutions for combining diverse data formats and the possibility of using advanced digital technologies, such as Building Information Modelling (BIM), to facilitate a seamless transition from traditional NDT approaches to a digitized, model-based inspection framework. The findings highlight the advantages of each NDT method, address specific data acquisition challenges, and propose strategies for overcoming issues related to data integration, visualization, and the accuracy of spatial localization. Integrating these NDT technologies within a georeferenced 3D GIS environment facilitates a detailed understanding of the bridge's condition and enhances decision-making processes for maintenance and rehabilitation efforts.