Highway structures such as bridges are subject to continuous degradation primarilydue to ageing, loading and environmental factors. A rational transport policy mustmonitor and provide adequate maintenance to this infrastructure to guarantee therequired levels of transport service and safety. Increasingly in recent years, bridges arebeing instrumented and monitored on an ongoing basis due to the implementation ofBridge Management Systems. This is very effective and provides a high level ofprotection to the public and early warning if the bridge becomes unsafe. However, theprocess can be expensive and time consuming, requiring the installation of sensorsand data acquisition electronics on the bridge. This paper investigates the use of aninstrumented 2-axle vehicle fitted with accelerometers to monitor the dynamicbehaviour of a bridge network in a simple and cost-effective manner. A simplifiedhalf car-beam interaction model is used to simulate the passage of a vehicle over abridge. This investigation involves the frequency domain analysis of the axleaccelerations as the vehicle crosses the bridge. The spectrum of the accelerationrecord contains noise, vehicle, bridge and road frequency components. Therefore, thebridge dynamic behaviour is monitored in simulations for both smooth and rough roadsurfaces. The vehicle mass and axle spacing are varied in simulations along withbridge structural damping in order to analyse the sensitivity of the vehicleaccelerations to a change in bridge properties. These vehicle accelerations can beobtained for different periods of time and serve as a useful tool to monitor thevariation of bridge frequency and damping with time.
展开▼
