Characterization of damage to steel bridge girders subjected to over-height vehicle collision

Abstract

Bridge structures that span roads and highways are often at the risk of over-height vehicle collision. Such collisions can cause structural damage to bridge girders, adversely affecting the bridge's safety and functionality, while posing an immediate hazard to traveling motorists. To ensure the structural integrity of the bridge girders, it is imperative to evaluate them in response to the loading demand induced by over-height collisions. However, current specifications and codes do not have the details necessary to predict the impact forces that steel bridge girders can experience during such collisions. To address this gap, a comprehensive investigation was conducted in this study to (i) determine impact force characteristics, (ii) evaluate various impact-induced structural response measures, and (iii) identify design parameters in need of attention to minimize the extent of impact-induced damage to steel girders. For this purpose, nonlinear finite-element models were developed and validated with experimental tests and field surveys. The structural performance of the steel bridge girders was then investigated, in terms of damage patterns, girder displacements and rotations, shear forces and bending moments, and impact forces, during a range of over-height collision scenarios. Based on the obtained results, predictive equations were developed to estimate the mean impact force. This was to facilitate the impact-resistant design of steel girders commonly used in bridge structures.