An Investigation into the Impact of Time-Varying Non-Conservative Loads on the Seismic Stability of Concrete-Filled Steel-Tube Arch Bridges

• Published in: Buildings (Basel) Vol. 14; no. 9; p. 2739
• Main Authors: Han, Xu, Han, Bing, He, Yikuan, Li, Pengfei, Xie, Huibing
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2024
• Subjects: Arch bridges; Bridge decks; Bridge loads; Bridges; Concrete; concrete-filled steel tube; Conservatism; Deformation effects; Design; Dynamic stability; Earthquake loads; Finite element analysis; Force distribution; Ground motion; Investigations; non-conservative force effect; Resonant frequencies; Seismic activity; Seismic stability; Steel columns; Steel pipes; Steel tubes; Stiffness; Stress distribution; suspender; time-varying behavior; Waveforms; Yield stress; China
• DOI: 10.3390/buildings14092739
• ISSN: 2075-5309

When the arch rib of the mid-bearing through and lower-bearing through arch bridges undergoes out-of-plane deformation, it is usually subject to the resilience force provided by the flexible hanger, which is known as the “non-conservative force effect” of the suspender. In contrast to the static condition, in the dynamic scenario, the time-varying non-conservative force exerted by the flexible suspender becomes more complex due to dynamic changes in external load. Moreover, the difference in fundamental frequency and vibration period between the bridge system and arch rib may influence the stress distribution within the arch rib during ground motion. This paper investigates the impact of time-varying non-conservative forces on the dynamic stability of arch ribs in concrete-filled steel tube (CFST) bridges under seismic loads. Specifically, it examines the influence of different seismic waveforms, frequency disparities between bridge slabs and arch ribs, and suspender stiffness on the non-conservative effect. The results reveal significant disparities in the impact of non-conservative forces exerted by the suspender during seismic events with identical intensity but varying frequency characteristics. The influence of non-conservative forces on the dynamic stability of bridges escalates as deck stiffness increases, while it remains relatively unaffected by changes in suspender stiffness.