Different Techniques for the Modeling of Concrete Box Girder Bridges

This paper presents a comparison between response of post-tensioned concrete box-girder bridges analyzed by using different modeling techniques. Each type of modeling technique requires a certain set of assumptions to simplify the problem and thus results obtained from these techniques vary according to the assumptions made. In this study, a typical concrete box-girder bridge is analyzed using commercially available finite element software for two analysis cases, static and modal. Static analysis is used to study the responses of the bridges for dead load, moving load and post-tensioning load cases whereas modal analysis is used to study modal dynamic responses of the bridge. Finally, response of the bridge is compared in terms of natural time periods, mode shapes, support reactions, deformations, and internal forces. This study shows that with proper assumptions, similar results can be achieved from different modeling techniques.