Influence of Surface Irregularities on the Dynamic Response of Minor Highway Bridges

In the present paper the effect on the dynamic application factor of bridge response from the surface irregularities is investigated. A numerical 3D model has been formulated for a 48t Scania truck. Further, a characteristic minor highway bridge has been selected, and a numerical FEM-model has been formulated. Based on measured data, a 2D spectral description of the road roughness is established which models the deterministic trends in transversal (wheel tracking) as well as longitudinal direction (some long-waved tendency). Further, the bumps/ expansion joints at the approaches to the bridge are included into the model. Based on a Monte Carlo simulation study the mean value and the variational coefficient of several dynamic amplification factors have been calculated assuming the parameters describing the vehicle and the bridge deterministic at characteristic values. The overall conclusion from this study is that the most important impact on the magnitude of the dynamic amplification factor stems from short waved bumps.