Analysis and Design of Cable Stayed Bridge

Abstract

Man has achieved a lot in field of Structural Engineering as it is most evident in the World's largest bridge spans, tallest structures etc. In the recent years cable stayed bridges have received more attention than any other bridge mainly, in the United States, Japan and Europe as well as in third-world counties due to their ability to cover large spans. Cable-stayed can cross almost 1000m (Tatara Bridge, Japan, Normandie Bridge, France) In India few of the cable stayed bridges are constructed and a couple of them are underway. Like Bandra-Worli sea link, Second Hoogly Bridge are the finest example of application of cable stayed bridge in India. Cable stayed bridges for road over bridge in Bangalore and Chennai have come up and a cable stayed road over bridge is proposed in various smaller emerging cities. There is still place for innovation in Cable-stayed bridge techniques Here detail study of the cable stayed bridge is done. Historical facts, various compo- nents of the bridges, types of the pylon arrangements, type of the cable configuration arrangements has been done to give a brief idea about cable stayed bridge from the various literature surveyed. For validation of the software used an example solved in a technical paper has taken and verified. Cable stayed bridge of 200m span having 100m central span with H type pylon shape and with semi-harp type cable configuration has been taken for analysis in SAP2000. The cable stayed bridge is modeled with proper technique from the guidance of various literature surveyed. Then study for the behavior under various loading is undertaken. Live load was taken according to IRC 6:2000. IRC Class A and Class 70R vehicle load along with Aerostatic wind loads was undertaken. A Dynamic analysis in the form of linear Time-History is also carried out to investigate dynamic response of the Cable-stayed Bridges and various response quantities such as Bending-moment, Shear-force, Torsion and Axial force are represented. Then a Parametric Study has been carried out by varying the shape of the pylon and the central span of the bridge. The shapes here taken for study are H shape, A shape, Diamond shape, Delta shape, Inverted Y shape. The span taken for study varied from 200m,400m,600m,800m. The linear and dynamic case has been compared for the response quantities. The result of study is represented in graphical form for various response quantities like Bending-moment, Shear-force, Torsion and Axial force. The performance of different shape are better for different response quantities so it cannot be merely concluded form analysis which is better so a detailed cost comparison can only give the better shape suitable by designing each shape and components. Design of the cable stayed bridge is performed for 200m H type Cable stayed bridge. The cable are designed by taking maximum axial force acting on it and the providing the number of cables required for resisting the force. Pylon are designed as slender column with biaxial moment and axial force. Box Girder is designed as Pre-Tensioned three cell Box Girder. Pile foundation is provided as foundation.