Nonlinear response of composite steel-concrete bridges

Abstract This paper is concerned with the overload behavior of a composite beam-slab type highway bridge consisting of steel stringers supporting a cast-in-place reinforced concrete slab. A nonlinear finite element analysis is used to determine the complete state of stress and deformation at any level of overload. A layered model together with an incremental iterative procedure is employed to determine the response of the bridge in the post-elastic range. The results of this analysis are compared with available experimental results for the case of a simply supported bridge. The bridge response under overloads is investigated, and the effects of some major design parameters are studied. Among these parameters are: beam size, torsional constant, slab thickness, Poisson's ratio, yield stress of steel girders and the ratio of transverse to longitudinal stiffness of the slab. The results obtained from this computer analysis compare favorably with experimental results in the elastic and the post-elastic range.