HEAVY TRAFFIC DETECTION USING ACCELEROMETRIC AND DISPLACEMENT SENSORS

This paper deals with the results of a dynamic monitoring system installed on a three span bridge of the Italian road network. The setup includes accelerometers, inertial displacement sensors, and displacement transducers. The main objective is to evaluate the dynamic re-sponse of the deck under normal traffic conditions, with particular attention to the identifi-cation of heavy vehicle transits. The proposed methodology combines the joint analysis of acceleration and displacement measurements recorded during traffic induced events. In ad-dition, relative movements at the expansion joints are investigated to assess the consistency of the overall structural behaviour under service conditions. The study also aims to assess the possibility of detecting heavy traffic events by means of threshold values applied to the measured dynamic accelerometric and displacement quanti-ties. The identification of vehicle transits is particularly relevant for bridges located in re-mote areas, where simple and low power monitoring systems may provide useful information on the operational conditions of the infrastructure without requiring continuous video based traffic surveillance. The proposed approach is intended to provide useful indicators for the identification of traffic induced loading conditions and for the assessment of the operational behaviour of the bridge under service conditions.