DESIGN OF BOX GIRDER BRIDGES

Abstract

Reinforced concrete box girder bridges, single or multi-celled, are being used more and more in the modern highway construction for long and medium spans owing to their aesthetic appearance and their structural efficiency. The typical box girder bridge (Fig..) consists of top and bottom concrete slabs monolithically connected by vertical webs to form a cellular or box—like etruoture. The central portion of concrete which is least efficient as a structural carrying medium in the longitudinal direction has been removed resulting in considerable reduction of the self weight of the bridge but only a small reduction of longitudinal stiffness. The voids thus created complicate the transverse structural action of the bridge section. These voids on the other band could be used for services.