Analysis of box-girder bridges by macro-element substructural method.

Abstract

An efficient macro-element substructure method for static analysis of straight box-girder bridge structures is successfully developed. The structure is considered as an assemblage of macro-element substrates. All of these macro-element substructures are identical in geometry. Each substructure is derived by applying the principle of static condensation in solving its equilibrium equations. Stiffness and load matrices of each substructure are assembled by rectangular flat shell elements which are composed of 8 degrees of freedom membrane stress and 12 degrees of freedom plate bending elements. This special purpose macro-element substructure method provides considerable efficiency in practical designs of straight box-girder bridges. A computer program is developed in which the proposed procedures are implemented, and several numerical examples are presented which compare the proposed method with other numerical methods. Good agreement is found in all these examples.