Reliability Assessment of Tie-Down Cables for Cable-Stayed Bridges Subject to Negative Reactions: Case Study

Abstract

Abstract This paper presents a reliability assessment for tie-down cables of cable-stayed bridges subject to negative reactions. The advanced first-order second-moment reliability method (AFOSM) is used to evaluate the reliability indexes. The strength of a tie-down cable and load parameters are selected as random variables. A Newton-type solution scheme with double iteration loops is used to solve the minimization problem defined in the AFOSM. Reactions at supports are calculated through the stiffness equation formed by a finite-element model, and the sensitivities of the reactions with respect to the random variables are obtained by the direct differentiation of the stiffness equation. The reliability indexes of the tie-down cables are evaluated for two cable-stayed bridges in service in Korea: the Second Jindo Grand Bridge and Incheon Grand Bridge. Three limit states on the pretension, required strength, and design strength are considered for the load combination of the Strength I limit state in LRFD b...