Local dynamic response in deck slab of a concrete box girder bridge

Abstract

With the effect of vehicle-bridge coupling considered, the local dynamic response in deck slabs of concrete box girder bridges was analyzed under the condition of vehicle-bridge coupling vibration. The mathematical model assumed a finite element representation of the slabs with shell elements. The vehicle simulation used a 3 dimensional linear vehicle model with 7 independent degrees of freedom. A well-known power spectral density of road pavement profiles was used to define the road surface roughness as Perfect, Good and Poor roads, respectively. Response data were produced on concrete highway bridge decks made of straight box section girder. In this way, a parametric study was conducted to analyze the effects of factors such as road surface roughness, vehicle speed, and bridge damping on the bridge dynamic amplification factors (DAFs). The analytical results suggested that the local DAFs in different locations of the slab or in the same location but made of different response vary widely. It is irrational to account for the impact effect of vehicles on the slab with a single DAF. Road roughness is the most important parameter affecting the dynamic behaviour of deck slabs. There is no critical speed or clear relationship between the DAFs and speed.