Novel Assessment Method for Support Conditions of Concrete Pavement under Traffic Loads using Distributed Optical Sensing Technology

Abstract

Loss of support is a common concrete pavement distress that may affect pavement performance directly. Previous studies have proved that vibration-based methods have the potential for detecting loss of support in a more efficient way but this is limited by loading conditions. This paper presents a further study concerning the effects of moving loads and proposes a novel method for assessing support conditions of concrete pavement under traffic loads using distributed optical vibration sensing technology. First, finite element analysis and laboratory tests were conducted to investigate the impact of loss of support on pavement vibration induced by moving loads with reference to the frequency spectrum. The impact of loading conditions, including loading position and speed, was also studied using the same methods. The results indicate that both loss of support and loading characteristics have a considerable effect on the distribution of the frequency spectrum. It is proved that weighted frequency can be utilized for assessment of support conditions under a specific loading condition. It is suggested the loading position needs to be close to the measurement point (distance < 0.3 m) to obtain stable and reliable data for assessment of support conditions. In addition, the loading speed should be adequately fast and steady (4 to 5 m/s) to ensure the significance of the effect of loss of support. A field test was conducted in an airport, and the novel assessment method was validated by comparing it with a conventional deflection-based method. The novel method proved to be reliable for implementation in practice.