Reliability Assessment of Incheon Bridge for Accidental Rupture of Stay Cables

Abstract

In this paper, DAF important examination variable in cable rupture for cable bridges is calculated through time history analysis and reliability assessment of structural is performed for load combination and resistance strength used in reliability based limit state design method for accidental cable rupture. The DAF is calculated by simulating the cable rupture by applying external force to the ruptured cable to maintain the initial equilibrium state and by applying the external force as a ramp load as a function of time. Here, 2% damping ratio was used for Rayleigh-Damping and direct integration method using Newmarks method for time history analysis. For dynamic analysis of cable elements, the initial cable tension is calculated using the elastic catenary cable static analysis and then cable elements are approximated as an equivalent truss element, suggested by Ernst. Reliability assessment of cable rupture is done using the load combination and resistance strength from the Korean highway bridges design code (limit state design) using AFOSM. Reliability assessment is performed for required resistance strength of ULS1 that governs the cable and stiffened girder cross-section design and load combination of ALS3 for examination of cable rupture.