Investigations on the behaviour of concrete box girder bridges

Abstract

A bridge is a structure built to span physical obstacles without closing the way newlineunderneath for the purpose of providing passage over the obstacle. Bridges can be newlinecategorized in several ways namely, based on the type of structural elements used, kind newlineof cross-sections, by what loads they carry, whether they are fixed or movable, and the newlinematerials used. newlineIn the family of long span bridges, concrete box girder bridges are widely used newlinethroughout the world. This is because of their high structural efficiency as well as better newlineaesthetics compared to open-web type cross-sections. The single and multi-cell box newlinegirders made of reinforced or prestressed concrete with vertical or inclined webs, are newlinepreferred as the most economic and aesthetic solutions for over crossings, under newlinecrossings, viaducts etc. The present trend in concrete box girders is to use thinner webs newlineand flanges in order to reduce the self-weight. However, the presence of eccentric loading newlinemakes the structural interactions complex in thin-walled closed cross-sections. A typical newlinebox girder behaves like a beam where the longitudinal flexural action is accompanied by newlinetransverse bending along with the effects of warping and distortion. newlineThe fast growing traffic has led to the emerging need in the expansion of highway newlinenetwork which includes the construction of bridges. The new trend in highway newlineengineering is to use larger carriage way width to accommodate this increased traffic. newlineThis leads to the construction of more multi-cell box girder bridges. But it is found that newlinewith the increasing number of cells, the complexity involved in construction increases. newlineBecause of this there is an increase in the demand to construct twin-cell box girder bridges newlinewhere multi-cell box girder bridges are necessary. In review of literatures, it was found newlinethat most of the work has been reported in single-cell box girder bridges whereas, studies newlinein twin-cell box girder bridges are limited. newlineSimplified methods are available for the design of box girder bridges.