Refined analysis of steel girder bridges for computation of live load distribution factors considering effects of freight and emergency vehicles

Recent revisions to federal guidelines require state departments of transportation (DOTs) to rate bridges in their inventory with special hauling vehicles (SHVs) and emergency vehicles (EVs). In this research, refined analysis method was used to compute live load distribution factors of steel girder bridges considering the impacts of SHVs and EVs on the live load distribution behavior. To determine the live load distribution factors for interior and exterior girders under different lane loading conditions, finite element models of twenty-one steel girder bridges from the state of Virginia were developed and then analyzed. The effects of vehicle type and transverse position on the results of the refined analysis were evaluated. The results were comparatively evaluated with those obtained using AASHTO LRFD equations. The live load distribution factor of steel girder bridges with various geometrical parameters were predicted using a series of linear regression models that were built using the data from the numerical simulations. The developed models can be used to identify bridges whose rating factors will be improved through refined analysis when these bridges are susceptible to posting.

Automated summary

Recent revisions to federal guidelines require state DOTs to rate bridges with SHVs and EVs. This research used refined analysis to calculate live load distribution factors of steel girder bridges considering the impacts of SHVs and EVs. Finite element models of 21 steel girder bridges from Virginia were used to determine the distribution factors under different lane loading conditions. The developed models can identify bridges that can be improved through refined analysis.