A MATERIALLY NONLINEAR FINITE-ELEMENT MODEL FOR THE ANALYSIS OF CURVED REINFORCED-CONCRETE BOX-GIRDER BRIDGES

A layered finite element model with material nonlinearity is developed to trace the nonlinear response of horizontally curved reinforced con crete box-girder bridges. Concrete is treated as an orthotropic nonlin ear material and reinforcement is modeled as an elastoplastic strain-h ardening material. Due to the fact that the flanges and webs of the st ructure are much different both in configuration and in the state of s tresses, two types of facet shell elements, namely, the triangular gen eralized conforming element and the rectangular nonconforming element, are adopted to model them separately. A numerical example of a multi- cell box-girder bridge is given and the results are compared favourabl y with the experimental results previously obtained.