Investigations into the use of distributed fibre optic sensors for detecting traffic-induced strain conditions in road structures

Monitoring strain conditions in road structures is crucial for maintaining their integrity and extending their lifespan. However, traditional methods often fall short in providing continuous, real-time data. This study investigates the potential of fibre optic sensors, specifically distributed fibre optic sensing (DFOS) technology (OFDR, DAS, DTS), for detecting strain conditions in road structures. Experiments conducted at the duraBASt test site and a pilot application on an in-service motorway demonstrate the feasibility of using DFOS to measure strain and detect vehicle crossings with high spatial resolution. The results show a close correlation between externally applied loads and internally measured strain values, indicating the technology's promise for monitoring road structures under various traffic conditions. The scope of this work extends beyond general traffic monitoring and load measurements to specifically address the accuracy and the repeatability of determining vehicle position, speed, and weight, ensuring precise spatial and temporal localization of individual vehicles. With its ability to provide continuous monitoring, fibre optic sensing technology offers a significant advancement in road construction and maintenance, enabling more accurate assessments of road condition and more efficient maintenance scheduling. Future applications could include integrating this technology into smart road systems for real-time traffic monitoring and structural health assessment.