Inelastic analysis of beam-slab bridges, July 1975

This dissertation describes an analysis scheme to predict the overload response of simple-span, right or skewed, beam-slab type highway bridge superstru~tureswith a reinforced concrete deck slab and reinforced or prestressed concrete beams. As a subset of the overall investigation, analytic models for both the individual beam and slab components of the bridge supe rstructure are presented. The analysis scheme employs the finite element displacement method. The bridge superstructure is discretized into beam and slab fi~ite elements. These finite elements are allowed to defonn in both bending and in-plane displacement modes. To allow for the initiation and propagation of material nonlinearity du-ring ove.rl·oading, the beam and slab finite elements are divided' into a ser"iesof ,layers through their depth. Nonlinear stressstrain laws are employed on a layer by layer basis. Each layer is assumed to be in the plane state-of-stress. Beam concrete, prestressing steel, and beam arrd slab mild steel reinforcement are assumed to be stressed-, uniaxially. J~ biaxial s tress field is used' for the slab concrete. In a,ddition to the inelastic stress-strain behavior, nonlinearities including cracking and crushing of the concrete and yielding of the steel are also considered. In order' to solve for the