Computer Modeling and Weight Limit Analysis for Bridge Structure Fatigue Using OpenSEES

Abstract

With the increasing demand in freight transportation, truck overloading has become a common issue worldwide. Overloaded trucks pose great challenges for transportation administration in that they can jeopardize the safety of bridges and even lead to bridge collapse. Traditionally, vehicle-induced damage on bridges was estimated based on the line-girder analysis, as suggested by bridge design codes. These analysis methods have been criticized to overly underestimate the bridge capacity. In this study, the fatigue damage (FD) of a typical composite girder bridge under truck overloading was investigated using the OpenSEES framework. The bridge system was regarded as a series-parallel system composed of concrete deck slab and a steel girder subsystem. A method for determining rational vehicle weight limits for highway bridges to achieve the desired service life was proposed considering the FD of bridges. The proposed method could also be used for estimating the FD of bridges caused by truck overloading. Numerical simulation results obtained from this study have shown that the cumulative FD of bridges under severe overloading conditions could increase rapidly, and it may threaten the safety of bridges, which underscores the importance of enforcing truck weight regulations on highway bridges.