NONLINEAR-ANALYSIS AND COLLAPSE LOAD OF P/C CABLE-STAYED BRIDGES

An analysis is described that models the behavior of planar prestressed concrete cable-stayed bridges up to failure taking into account geometric and material nonlinearities. The geometric nonlinearities arise from cable sag, large deformations of the system, and from the shift of the centroid of the deck section caused by the material or by cracking of the concrete. The effect of the axial forces on the stiffness of the members is also considered. Material nonlinearities are encountered when one or more of the structure components, namely the stay cables, prestressing tendons, the reinforcement, or the concrete, exceed their elastic limits. Parametric studies are made on cable-stayed bridges with the following cable arrangements: fan, semifan and harp-type cable arrangement. To demonstrate the influence of the different types of nonlinearity on the internal forces and reactions three analyses were performed—namely elastic, geometric nonlinear, and geometric and material nonlinear analyses—and the results are compared. © ASCE.