Prestress Loss Identification Based on Dynamic Vehicle Responses

How to detect the prestress loss of the bridge in a fast and economical way is still a challenging problem for bridge engineers. Although some sensors have been developed to monitor the prestress, it is usually difficult and expensive to install, maintain, and monitor these sensors. Drive-by inspection, using vehicle response to identify the prestress loss, could be a good alternative. In this paper, an earlier-developed prestressed bridge vehicle interaction model has been modified to account for the influence of effective rigidity and the gravity load. Both half and quarter vehicle models were adopted in the study. Numerical simulations were conducted to show that light, low-frequency vehicles moving at low speeds have a better performance in detecting the bridge prestress loss than the heavy, high-frequency vehicles with high speeds. Also, the maximum vertical acceleration of vehicles could correlate with the prestress loss very well.