ANALYSIS OF BOX-GIRDER BRIDGES USING FINITE ELEMENT METHOD

Abstract

An efficient transport system is a basic infrastructural facility required in any country for movement. To ensure all-weather transport system, bridges have special importance. In todays fast modern world the ever increasing demand for expansion of highway network, to cater for increased traffic, has thrown challenges on researchers and designers to provide best innovative bridge structures. It has led to many changes in the development of various kinds of bridges. Box girders, often used as a basic component in modern bridge structures made of steel or prestressed concrete, are . _ attributed to their better stability, serviceability, economy, aesthetic appearance and structural efficiency due to high torsional stiffness. Box girders usually prove to be economical in the span range of 20 m to 40 m in case of reinforced concrete bridges and in the span range of 40 m to 100 m in case of prestressed concrete bridges. Beyond 100 m span, cable stayed box girder bridges are becoming popular [Heins and Lawire 1984]. Use of box girder in bridges has become popular during last three decades.Box girder bridges were initially used in road bridges but, since past 20-25 years, these are mostly7tr the flyover bridges in the urban area. Initially, reinforced concrete bridges and linear methods of analysis were employed in bridge design but in recent years since 1977 the emphasis has shifted to prestressed concrete bridges alongwith non linear methods of analysis [Yilmaz and Wasti 1984]. The Deformation of thin walled box sections and associated longitudinal warping produce distortional stresses which are influenced by factors such as section