Overload Behavior of Composite Steel-Concrete Bridges

This study is concerned with the overload behavior of composite steel-concrete highway girder bridges. The post-elastic behavior is investigated, and the effect of some design parameters on bridge response is studied. This paper describes a nonlinear finite element analysis procedure permitting the determination of the state of stress and deformation under given levels of overload. The nonlinear behavior of the structure due to the various sources of nonlinearity: crack propagation, concrete yielding and crushing, and yielding of the reinforcing steel and girder steel is reproduced through the use of appropriate constitutive laws. A shear retention factor is introduced to account for aggregate interlock and dowel action. An analysis of the effects of discretization and of some material properties on bridge response in the post-cracking range is included, and numerical examples are presented to confirm the validity of the developed numerical solution procedure.