Dynamic Analysis of Steel Curved Box Girder Bridges

The impact of seven three-span continuous single box girder bridges, with overall span lengths ranging from 76.2 to 213.36 m (250–700 ft), due to vehicles moving across rough bridge decks is analyzed. The box girder is divided into a number of thin-walled beam elements. Both warping torsion and distortion are considered in the study. The analytical vehicle is the HS20-44 truck included in the American Association of State Highway and Transportation Officials specifications and simulated as a nonlinear vehicle model with 11 degrees of freedom. Truck parameters include the body, suspensions, and tires. The bridge deck surface is assumed to be good and was simulated using a stochastic process (power spectral density function). The analytical results show that the impact factors of torque and distortional torque for the curved single box girder bridges could be very high, while those of the other responses are generally less than that of corresponding straight box girder bridges. The proposed impact equations can be used in the design of continuous curved single box girder bridges.