EVOLVING SEQUENTIAL CONSTRUCTION FOR UNEQUAL SPAN CABLE STAYED BRIDGES

Abstract

The techniques and methods of erecting cable-stayed bridges are varied and numerous. The erection method not only affects the stresses in the structure during erection but may also have an effect on the final stresses of the completed structure. Calculations for stages of the erection are aimed, in the first place, at proving that the stress conditions set up during construction are less than those used in the dimensioning. They may also be used as a basis on which to decide the actual method of erection. The cable-stayed road over bridge being constructed across the Bangalore-Chennai railway line near Krisimarajapurarn Railway Stations considered fare for the calculation of the erection stages. The bridge is being erected by the c:antiiever erection method. The Backward substitution method is adopted, which consists of assuming the structure to be completed, and showing, in the calculations, how it is Effected at the various stages, working backwards from completion. Only. the method of corbelling out on stays, which rr►-akos an immediate use of the presence of the stays, is touched on here. In this construction method, the erection calculations are also aimed at determining, at every stage of construction, the forces required in the stays and the consequent successive deformations, likely to be revealed in the final longitudinal profile of the roadway. The analysis was carried out with the commercially available package STAAD-111.