Ultimate Behavior of Steel Cable-Stayed Bridges During Construction

Abstract

This paper presents an investigation of the ultimate behavior of steel cable-stayed bridges under construction. In general, cable-stayed bridges are subjected to quite large compressive forces induced by stayed cables, and may become unstable due to these excessive compressive forces, especially while under construction because of the characteristics of the general construction method. To investigate the ultimate behavior of steel cable-stayed bridges under construction, a three-step analysis, consisting of initial shape analysis, construction stage analysis and external load analysis, is proposed and used with considering various geometric and material nonlinearities of the structure, such as the cable-sag effect, beam-column effect of the girder and mast, large displacement effect and gradual yield effect. By performing extensive analytical study, the general ultimate behavior and mode are found and described in detail. Also, the effects of various geometric parameters on the ultimate behavior and load carrying capacity are studied, such as the cable-arrangement types, girder-mast flexural stiffness ratio and sectional area of stay cables.