Nonlinear dynamic analysis of long-span cable-stayed bridges with train\u2013bridge and cable coupling

Zhihui Zhu,Anand Patil,Michael T Davidson,Lidong Wang,Issam E Harik

doi:10.1007/s40091-019-0229-1

Abstract

Span lengths of newly constructed cable-stayed railway bridges continue to show increases relative to those of older bridges. Accompanying such increases is the importance of ensuring that vibrations of long-span cable-stayed bridges satisfy both safety and serviceability requirements, particularly for bridges that support train passages. In contrast to modern design of bridges that support roadway vehicles, current methods for analyzing cable-stayed railway bridges do not yet typically account for coupling effects that may occur between cables and the surrounding bridge structure during train passages. This paper presents a computational framework for the nonlinear dynamic analysis of railway bridges based on a coupled train–bridge analytical model and investigates the significance of accounting for cable-related coupling effects. A case study is then carried out, where coupled dynamic responses of cables, towers, and girders of an in-service railway bridge are computed and compared to those obtained using an uncoupled approach. These comparisons demonstrate the merits of accounting for coupling phenomena when computing dynamic characteristics of cable-stayed railway bridges and highlight benefits of the coupled analysis approach in bridge design applications.

Highlights

Considerations for the vibrations of long-span cable-stayed bridges that are produced during train passages are increasingly recognized as important components of modern design practice
The objectives of this study are to: (a) present a computational framework for calculating nonlinear dynamic responses of long-span cable-stayed bridges subjected to moving trains, where train–bridge coupled vibrations— including those of the cables—are taken into account; and (b) identify advantages of the proposed approach relative to the one element cable system” (OECS) model
This study proposed a computational framework to analyze nonlinear dynamic responses of long-span cable-stayed bridges subjected to moving train loads, on the basis of a train–bridge coupled system

Summary

Introduction

Considerations for the vibrations of long-span cable-stayed bridges that are produced during train passages are increasingly recognized as important components of modern design practice. Characterization of dynamic behaviors that arise during train passages across long-span cable-stayed bridges is essential to upholding design constraints for safety and economy. The importance of accounting for local vibrations as contributors to global dynamic response of cable-stayed bridges has been consistently recognized in previous studies (AbdelGhaffar and Khalifa 1991; Warnitchai et al 1995; Caetano et al 2008; Zárate and Caicedo 2015). The effects of cable vibrations on bridge deck and pylon responses (e.g., nonlinearities associated with beam–column effects; the initial equilibrium state; and large-displacement kinematics effects) are neglected (Cai and Aref 2014)

Objectives

14 Cable number

80 C39-G 60 40 20

Findings

Conclusions