Vehicle-bridge coupled vibration analysis and calculation of dynamic impact factor for the PC box-girder bridge with corrugated steel webs

As a new type of steel-concrete composite structure, the pre-stressed concrete (PC) box-girder bridges with corrugated steel webs(CSWs)have been widely used in bridge engineering all over the world because of their excellent mechanical performance and light weight. Research on the dynamic response and dynamic impact factor (IM) of this new structure are limited, and no standard file has yet been established. In order to determine the IMs of the simple supported PC box-girder bridges with CSWs scientifically and reasonably, the two systems of motion equations for the vehicle and bridge are coupled through the contact condition between the vehicle wheels with bridge deck. Considered the random excitation effects of road surface profile, the vibration responses of the bridge nodes can be obtained by using the MATLAB program to solve the dynamic equation of vehicle-bridge system and the IMs of simple supported PC box girder-bridge with CSWs can be obtained. The obtained numerical IMs are compared to IMs obtained from the General Specifications for Design of Highway Bridge and Culverts JTG D60-2015 and IMs based on the formula of fundamental frequency proposed by the author. The results show that under the average road surface conditions, the IMs calculated using the proposed formula of fundamental frequency are in good agreement with IMs based on the fundamental frequency calculated by the finite element method suggested by the JTG D60-2015 and the IMs from numerical simulations, while have significant differences with the IMs calculated using estimation formula of the fundamental frequency suggested by the JTG D60-2015. The conclusions can provide a good reference for dynamic response analysis and determining the dynamic impact factors of PC box-girder bridges with CSWs. © 2016, Nanjing Univ. of Aeronautics an Astronautics. All right reserved.