INFLUENCE OF TRANSVERSE MEMBERS ON STRUCTURAL BEHAVIOUR OF GIRDER BRIDGES

Abstract

Girder bridges are the most suitable form of bridge construction for short and medium span range. With rapid urbani-zation it is difficult to avoid skew. Stiffness matrix method as applied to grillage analogy is the most popular computer method among designers. This has been adopted for tae present study work. The entire bridge deck which consist of longitudinal girders, cross beams, intermediate cross beams or diaphragms and slab, behaves as one integrated unit. It is pertinent to study the contribution of slab stiffness in distributing imposed loading. The study has been carried out to find out the influence of slab stiffness on the structural behaviour of girder bridge. Cross members may be in the form of cross beams or diaph- ragms. Now-a-days emphasis is more on diaphragms. The study has been done to compare the efficiency of diaphragms to that of cross beams in transverse distribution of imposed loading. The transverse load distribution in girder bridges is dependent on the number of intermediate cross beams. For a typical bridge of 25 m span, 30° skew a study has been made as to how many intermediate cross beams should be provided for the structure to behave in a best efficient manner.