Non-Linear Analysis of Cable Stayed Bridges

Abstract

The concept of cable-stayed bridges dates back to the seventeenth century. Due to their aesthetic appearance, efficient utilization of material, and availability of new construction technologies, cable-stayed bridges have gained much popularity in the last few decades. After successful construction of the Sutong Bridge, a number of bridges of this type have been proposed and are under construction, which calls for extensive research work in this field. Nowadays, very long span cable-stayed bridges are being built and the ambition is to further increase the span length using shallower and slender girders. In order to achieve this, accurate procedures need to be developed which can lead to a thorough understanding and a realistic prediction of the bridge’s structural response under different load conditions.In the present study, an attempt has been made to analyze the seismic response of cable stayed bridges with single pylon and two equal side spans. This study has made an effort to analyze the effect of both static and dynamic loadings on cable-stayed bridges and corresponding response of the bridge with variations in span length, pylon height and pylon shape. Comparison of static analysis results have been made for different configuration of bridges - their mode shapes, time period, frequency, pylon top deflection, maximum deck deflection; and longitudinal reaction, lateral reaction and longitudinal moment at pylon bottom. Time history analysis results have been investigated for different configuration of bridges under the effects of three earthquakes response spectrum (Bhuj, El Centro and Uttarkashi) - axial forces in stay cables, deck deflections and stress diagrams at maximum peak ground acceleration of the above mentioned earthquakes.