Probabilistic Seismic Sensitivity Analyses of High-Speed Railway Extradosed Cable-Stayed Bridges.

Featured Application: This study is aimed at sensitivity of seismic fragility demand parameters caused by structural uncertainty of high-speed railway extradosed cable-stayed bridge considering the Yuanjiang extra-large bridge on Huaihua–Shangyang–Hengyang Railway in China. Based on the probability distribution and correlation of random parameters, a sampling analysis method is proposed herein. Furthermore, a dynamic 3D finite element model of the employed bridge is established by using OpenSEES nonlinear software with full consideration of the randomness of structural parameters using sampling analysis. Based on these findings, some important conclusions were drawn. We believe that our study makes a significant contribution to the literature because although existing studies have focused on static parameter sensitivity analyses and have provided evidence for the design and construction control of cable-stayed bridges, the dynamic sensitivity studies especially for the structural parameter uncertainty of high-speed railway extradosed cable-stayed bridges have not been extensively studied. Further, we believe that this paper will be of interest to the readership of your journal because our analysis employs innovative research techniques, and our findings have the potential to provide guidance for the seismic fragility analysis of high-speed railway extradosed cable-stayed bridges. This manuscript has not been published or presented elsewhere in part or in entirety and is not under consideration by another journal. We have read and understood your journal's policies, and we believe that neither the manuscript nor the study violates any of these. There are no conflicts of interest to declare. It is known that the extradosed cable-stayed bridge, a hybrid bridge, possesses the virtues of both classic cable-stayed bridges and girder bridges in mechanical behaviors. In this paper, the sensitivity of seismic fragility demand parameters (SFDP) of a high-speed railway extradosed cable-stayed bridge is studied systematically along with the consideration of structural parameter uncertainty. Based on the probability distribution and correlation of random parameters, the Latin hypercube sampling method is adopted herein. The dynamic 3D finite element model of the employed bridge is established by using powerful and attractive OpenSEES nonlinear software. A nonlinear incremental dynamic analysis is performed to consider the randomness of structural parameters using sampling analysis. Some important conclusions are drawn indicating that the structural design parameter uncertainty predominantly has influence on the SFDP for fragility analysis of bridge structures. The design parameters of extradosed cable-stayed bridges are categorized and identified as primary, secondary and insensitive parameters. The high sensitivity parameters of extradosed cable-stayed bridges for fragility analysis include friction coefficient of bearing, concrete bulk density, damping ratio, peak compressive strength of confined concrete, component size and peak strain of confined concrete. Additionally, the strength and strain of unconfined concrete cannot be ignored. Furthermore, the uncertainty of structural design parameters fails to be responsible for the cable force responses due to larger girder stiffness. The structural design parameter uncertainty has a significant influence on the responses of extradosed cable-stayed bridges for seismic fragility analysis. [ABSTRACT FROM AUTHOR]