Vibration characteristics and load-carrying capacity of multiple steel plate girder bridges with corroded girder ends

Abstract

This study investigates the effects of corrosion on the vibrational characteristics and load-carrying capacity of steel plate girder bridge ends, which are extensively used in many bridges. First, eigenvalue and static analyses were performed using the finite element method, and the following main parameters were considered: the number of main girders, corrosion locations, and corrosion levels. The correlation between the results of the eigenvalue analysis and load-carrying capacity was examined; furthermore, to serve vibration-based health monitoring purposes, the selected parameters were investigated. The results indicated that the natural frequencies of the torsion-transverse coupling mode changed considerably as the corrosion ratio increased in the case of the corroded girder end and double-sided pin-bearing conditions. Additionally, a correlation between the natural frequency and load-carrying capacity was observed regardless of the number of main girders, indicating that the natural frequency and maximum load factor were related. In conclusion, the load-carrying capacity of corroded girder bridges can be estimated by measuring the transverse mode using an acceleration sensor installed on the upper flange and slab.