Dynamic Impact Factors for Simply-Supported Bridges Due to Vehicle Braking

Previous studies have shown that the dynamic impact factors of bridges caused by vehicle braking may exceed those prescribed in the bridge design codes. While simple vehicle and bridge models were used in most of the previous studies, a three-dimensional vehicle-bridge coupled model was developed in this paper to study the dynamic impact factors for bridges due to vehicle braking. This model is able to deal with more complex bridge structures than most of the existing models in the literature and can produce more reasonable results. Considerable dynamic effects were observed on the bridge responses as well as on the contact forces between the bridge and the vehicle due to vehicle braking. The effects of several important parameters, including the vehicle braking position, deceleration rate, initial vehicle speed, and road surface condition, on the dynamic impact factors were studied. In addition, a comparison was made between the dynamic impact factors caused by vehicle braking and acceleration.