Finite element analysis of box-girder bridges

This thesis presents an efficient numerical method for the structural analysis of box-girder bridges. The box-girders are assumed to behave as thin spatial plate structures, for which the finite element method is shown to provide an accurate mathematical model when quadrilateral shaped thin planar shell elements, with a linear variation of thickness and the three translational and rotational degrees of freedom at each vertex, are employed. Three dimensional beam elements with eccentric nodes are incorporated to model the kerbs, stiffeners, and piers of bridges. This finite element approach was used to perform linear elastic analyses of an extensive range of box-girder and slab bridges, the results of which are compared with published experimental or prototype measurements. The method was extended to enable the geometrically nonlinear response of imperfect flat plates and stiffened plate girders to be computed. Results are compared with analytical solutions, and experimental results where these are available.