Experimental validation of continuous pavement surface deflection measurement using embedded geophones and accelerometers

Pavement response monitoring (PRM) supports infrastructure management by evaluating pavement performance and optimizing maintenance strategies. This study experimentally validates a continuous PRM system using embedded geophones and accelerometers to measure pavement surface deflections under real traffic loads. The system is designed as a cost-effective and easy-to-install solution for continuous pavement deflection monitoring. Field experiments were conducted on the E16 Motorway in Borlänge, Sweden, a cold-climate region, where sensor signals were collected from passing heavy vehicles. Geophones and accelerometers measured pavement vertical vibration velocity and acceleration, respectively. Signal processing methods, including filtering, integration, and transformation, were applied to derive vertical pavement surface deflections. Measured deflections were compared with theoretical values calculated using the multilayer elastic response software ERAPave, showing low normalized root mean square error (NRMSE). Both sensor types accurately captured pavement surface deflections; however, geophones performed better, with an average NRMSE of 9.87% compared to 11.92% for accelerometers. Geophone measurements also showed close alignment between measured and calculated peak deflections, achieving an R² of 80%. This validation confirms the potential of embedded geophone and accelerometer setups as scalable, low-cost solutions for continuous PRM to support roadway maintenance and infrastructure durability.