A computer-based analytical model has been developed which will enable predictions to be made of vehicle-bridge interaction. In particular, the deformation of the bridge can be obtained when the predicted moments are in the nonlinear range of the bridge moment-curvature relationship. The analytical model allows for successive passages of vehicles and can be used to predict if the bridge will attain a permanent deformation or if the deflections will increase without bound.
The vehicle component of the model can be used to simulate the behaviour of many of the commercial vehicles presently in service. Experimentally obtained hysteretic nonlinear force-deformation laws are adopted for the vehicle springs and tyres. The vehicle response allows for varying road roughness and a definition of vehicle forward motion.
The response of the bridge is obtained by considering the path-dependant nonlinear constitutive laws of steel and concrete. The dynamic equations of motion of the vehicle and bridge are solved allowing for interaction between the vehicle tyres and bridge deck.
Verification of aspects of the model have been performed using available field observations and predictions obtained from other analytical research.
A comprehensive series of analyses have been undertaken to consider the effects of road roughness, vehicle velocity and number of vehicle passages on the performance of a bridge. Based on the results obtained empirical laws, which can be used to predict if the moments in the bridge will exceed its ultimate moment capacity, have been derived.