Determination of Dynamic Amplification Factor and Reliability Assessment for Accidental Rupture of Cables

Abstract

In this study, Dynamic Amplification Factor(DAF) is determined for the results of quasi-static analysis to reproduce the results of dynamic analysis properly and the safety of the adjacent cables is confirmed when the cable ruptures. There are two methods to check the safety of cables about cable rupture: Quasi-static analysis

Dy-namic analysis. Dynamic analysis is the exact method relatively between two meth-ods and the results of quasi-static analysis should reproduce the results of dynamic analysis. Therefore, it is important to determine exact DAF in order to use quasi-static analysis. In this study, not the meaning of DAF term itself but the similarity of the results which are obtained by two analyses is focused. First of all, dynamic analysis is performed and the result is set up as the standard. The results of quasi-static analysis are compared with that of dynamic analysis altering DAF. Prototype cable-stayed bridge, Incheon bridge and 2nd Jindo bridge which have various lengths of main girder are used as the examples of cable-stayed bridge and Yisunshin bridge, Ulsan bridge and New Millennium bridge are used as the examples of suspension bridge. Tension of the cables and moment of the girders are used as the standard of comparison and DAF is determined when the error between the results of two anal-yses is minimized. In addition, the reliability assessment about tension of the other cables is performed when the cable ruptures. The same examples which are used for the determination of DAF are identically selected for the reliability assessment. The cross-sectional area decreases using the simple Target Configurations Under Dead loads to design the cables suitable for Korean Highway Bridge Design Code(Limit State Design)-Cable Supported Bridge(2015) and the reliability assessment is per-formed about the tension of the cables.