Vehicle-based health monitoring system for short and medium span bridges

In this paper, one practical solution to the problem for condition assessment of short and medium span bridges is discussed. It uses vehicle-based measurements with a public bus as part of a public transit system. The system, named as bus monitoring system, is introduced along with safety indices and data analysis methods. It is shown that the bridge vibration response can be extracted from the measured vehicle response, and so called characteristic deflection to be calculated. Characteristics deflection is found to be relatively free from the influence of varying parameters like vehicle speed, bus overall weight and roughness of the road surface. It could therefore be used as structural performance indicator of the bridge. The system is operating in Ube-city, Japan, that is dealt as a case study.