ANALYSIS OF LONG SPAN BRIDGE

Abstract

Cable stayed bridges have come a long way in being recognized as indicators of the development of a country and adding to its touristic value. The safety of cable stayed bridges has been of great concern to engineers ever since the failure of the famous Tacoma Narrows Bridge in 1940. Cable stayed bridge is highly indeterminate structure and its behavior is very complex. Initial shape finding is most important task in cable stayed bridges which is greatly influenced by cable pretensions. Cable pretensions are calculated by different methods gives different results and some methos does not works for particularly for long span bridges bridge. Suitable methos for calculations of pretensions for large span bridge is discussed in this thesis. Linear analysis of cable stayed bridge done for dead load, superimposed dead load and live load. Though the material behavior is linear in cable stayed bridge, its overall behavior becomes nonlinear. Nonlinear analysis also performed for bridge under consideration using MIDAS CIVIL 2022 and ABAQUS software. The given bridge was analyzed for moving load along with the dead load. Moving loads are applied as per Indian standard specification and code of practice for road bridges IRC:6-2017, Section-II. Analysis done to check serviceability condition and strength criteria. Structural deformation is very important in serviceability conditions and its dependence on temperature variation is quite complex. The thermal actions continuously impose loading on the bridge structure. For the given bridge temperature effect is applied as per IRC:6-2017. The temperature gradient in the deck is applied as per IRC:6-2017. Construction stage analysis of cable-stayed bridges is the analysis of the bridge at different erection stages. There are various methods of construction of bridges depending upon the type of bridge, geometry, span, cable spacing, type of deck, the height of substructure, and site conditions. Construction stage analysis is also very important for construction of bridge with suitable method and achieving expected profile of deck during construction and postconstruction. Balanced cantilever method is used for construction stage analysis. The development of advanced software’s and improved computational capabilities of the 21st century has greatly aided the study of these types of analysis of cable stayed bridges.