Closure of "Bridge Vibrations Due to Vehicle Moving Over Rough Surface"

The dynamic response of a simply supported box girder bridge due to a vehicle moving across the span is presented. The effect of the randomly varying dynamic force generated by the vehicle moving over a rough bridge deck is considered in the analysis. A comparison is made of results obtained by modeling the vehicle and vehicle-pavement interaction as a single unsprung mass and as a concentrated time-dependent force. A statistical analysis of the results shows that peak impact factors for deflection, moments, and shear are considerably greater than those normally prescribed in bridge codes, especially when the vehicle is moving at high speeds. The effect of vehicle mass is also more significant at higher speeds.