Analysis of time-varying seismic fragility of rigid frame pier of offshore bridge

Abstract

PurposeAlthough mechanical behavior of rigid frame pier has been clearly recognized, their time-varying seismic performance are yet to be well characterized due to some offshore piers that are eroded by chloride ion and located in earthquake-prone area. In this study, the time-variant seismic fragility analysis was conducted to evaluate seismic performance of rigid frame pier under four damage states with considering the time-varying characteristics of the material.Design/methodology/approachThis paper establishes the nonlinear finite element model for the investigated offshore reinforcement concrete (RC) pier with considering the time-varying durability damage of the materials and defines the damage state, damage position and damaged index of the offshore RC pier. It also analyzes the time-varying seismic fragility of the offshore RC pier by using the capacity demand ratio method in the whole life cycle.FindingsThe results show that chloride induced corrosion has a significant effect on the rigid frame pier and bending capacity of top section is less than that of bottom section. The rate of decline accelerates after the service life reaching 30 years under the coupling of the earthquake and the environmental erosion. In the early years of service, the seismic fragility of the structure changed slowly.Originality/valueThis paper analyzes the influencing factors of seismic performance of rigid structure pier, and analyzes the seismic capacity and seismic performance of rigid structure pier under different service periods.

Time-varying seismic resilience analysis of coastal bridges by considering multiple durability damage factors

“…2.4.2 Carbonation of concrete. At present, the influence of carbonization on the strength of concrete materials is mainly considered in the research on the time-varying seismic performance of bridges (Liang et al, 2021(Liang et al, , 2022Yan et al, 2022;Zhong et al, 2023), while the influence of chloride ions on concrete materials is ignored. Therefore, this paper analyses the change in concrete properties caused by carbonization concerning the existing research.…”

A reliability-based design and optimization strategy using a novel MPP searching method for maritime engineering structures

“…Design optimization method based on safety factor is widely used in the design of maritime engineering structures (Motlagh et al ., 2021; Amin et al ., 2021; Gong et al ., 2018; Liang et al ., 2022; Liu et al ., 2017, 2019; Hegseth et al ., 2020; Zhu et al ., 2021; Bhardwaj et al ., 2023). Motlagh et al .…”

“…Design optimization method based on safety factor is widely used in the design of maritime engineering structures (Motlagh et al, 2021;Amin et al, 2021;Gong et al, 2018;Liang et al, 2022;Liu et al, 2017Liu et al, , 2019Hegseth et al, 2020;Zhu et al, 2021;Bhardwaj et al, 2023). Motlagh et al (2021) performed design optimization based on safety factor for offshore jackets using genetic algorithms.…”