Abstract
This paper investigated the nonlinear seismic performance of an existing cable-stayed bridge longitudinally subjected to a set of simulated near-fault ground motion pulses. An elaborated non-linear finite element model of the bridge was established which particularly considered cable sag effect, material nonlinearity of the tower and the deck. Through non-linear dynamic response analyses, seismic responses of the tower, deck and cables were evaluated at the yield and ultimate state of the structure. In particular, the yield and ultimate state of the structure were defined in the text based on damage levels of the structure and structural integrity requirement. It is revealed that the pulse period (Tp), by determining the relative contribution of multiple modes of the structure, strongly affected the damage process of the structure. As Tp was close to the period of first vertical vibration of the deck, the responses of the deck and cables were largely excited so that the deck might yield prior to yield of the tower, the cables failed prior to the ultimate state of the tower, and the deck suffered most of the damage despite of the yielding of the tower.
Highlights
During recent decades, cable-stayed bridges have gained worldwide popularity, owing to aesthetical appearance, structural efficiency and short construction period
Cable-stayed bridges are normally able to remain nearly elastic under the design seismic action which satisfies the recommendation of seismic codes like Eurocode 8 (De Normalisation 1998) and Chinese code (MCPRC 2008) and the reinforcement ratio of the tower legs is designed within economical range according to the design purpose
Chadwell and Fenves (2003) conducted analytical studies to investigate the seismic damage of Chi-Lu Bridge and speculated that ground motion pulses from near-field ground motions at bridge site might lead to the damage of the structure
Summary
Cable-stayed bridges have gained worldwide popularity, owing to aesthetical appearance, structural efficiency and short construction period. By exciting the model transversely, damage characteristics of the bridge model were observed including severe damage at upper strut, repairable damage at tower bottom and middle part, and minimal damage at lower strut Another shake table test was carried out on 1/20 scale model of a single-tower cable-stayed bridge which revealed the vulnerability of the tower, the cable and the bearings of the cable-stayed bridge under near-field ground motions (Yi and Li 2017, 2019). There is a clear need to associate the vulnerable components of a cable-stayed bridge with the characteristics of ground motions to have a good understanding of the seismic damage process of this type of bridges To this end, this study firstly established an elaborated non-linear finite element model of a real cable-stayed bridge in which several nonlinear responses including cable sag effect, material nonlinearity of the tower and the deck were carefully considered. The damage process of the structure affected by pulse periods was analyzed
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have