ABSTRACT Title of Thesis: ANALYSIS AND BEHAVIOR INVESTIGATIONS OF BOX GIRDER

Due to efficient dissemination of congested traffic, economic considerations, and aesthetic desirability horizontally curved steel box girder bridges have become increasingly popular nowadays in modern highway systems, including urban interchanges. Although significant research has been underway on advanced analysis for many years to better understand the behavior of all types of box-girder bridges, however, the results of these various research works are scattered and unevaluated. Hence, a clear understanding of more recent work on straight and curved box-girder bridges is highly desired. The non-composite steel section must support both the fresh concrete and the entire construction loads hence steel box girders are at their critical stage during construction. In the current study, non composite straight and curved steel boxes are analyzed with beam and shell elements using the three dimensional finite element analysis and their behavior is investigated. The present research addresses comparison using beam and shell element models of the straight and curved box girder bridge. This task involves examining the stress patterns obtained using static three-dimensional finite element modeling. Comparisons are made between stresses obtained for the straight and curved box girder bridges, from the beam element model and shell element model for each. Further, the finite element results are compared to the BEST center program DESCUS-II results. Finally, the parametric investigations are performed on the curved steel box model to evaluate the effects of several important parameters on the behavior of the girder