@article{9dffcbec603b47e8aea24d0cdafe9c0e,
title = "Seismic behaviors of PCIC piers-supported bridge structures to spatially varying ground motions",
abstract = "Damages to bridge piers were repeatedly observed in many previous strong earthquakes, resulting in disruptions to traffic and impairing the functionality of road network. Extensive studies have been carried out to improve the seismic resistance of bridge piers so as to enhance the seismic performances of bridge structures. In a recent study, an innovative pendulum-type column-in-column (PCIC) system was proposed to reduce seismic induced vibrations of bridge piers. This study extends the previous study on investigating the seismic performances of PCIC piers-supported bridge structures subjected to spatially varying ground motions (SVGMs). Three-dimensional (3D) finite element (FE) models of a typical 5-span continuous bridge supported by the conventional piers and PCIC piers are developed in the ABAQUS software in the present study, and numerical simulations are performed to evaluate the dynamic responses of bridges with conventional and PCIC piers. It is demonstrated that the PCIC piers can effectively mitigate the seismic responses of bridge structures. The SVGMs tend to amplify seismic responses of bridges, therefore need be considered when evaluating the seismic responses of multi-span bridges. The results demonstrate the great potentials of the applications of PCIC piers for seismic-resistant design of bridge structures.",
keywords = "Numerical simulation, PCIC system, PTMD, Spatially varying ground motions, Vibration control",
author = "Xiaojun Fang and Kaiming Bi and Hong Hao",
note = "Funding Information: Recently, a sliding-type column-in-column system (SCIC, Fig. 1(e)) [35] was proposed by the authors to mitigate the seismic induced vibrations of engineering structures. The idea of this novel column system is to separate a conventional solid or hollow column into an exterior and an interior column, while keeping the total elastic axial stiffness and axial loading capacity of the column-in-column system the same as the original one. Therefore, while the axial loading capacity of the SCIC system is not compromised and the construction cost is not significantly increased as compared to the conventional monolithic column [35], under transverse dynamic loads (e.g. earthquake and wind), the interior column with the interconnected springs and dampers to the exterior column can act as an unconventional TMD system [ 36–38] to mitigate structural vibrations. By simplifying the SCIC system to a double-beam system [39], the authors conducted theoretical analyses and derived analytical solutions to investigate the vibration characteristics of the system based on the Euler-Bernoulli beam theory [40]. Experimental and theoretical studies [41] were also performed to study the compressive behaviors of the SCIC system, demonstrating that the exterior and interior column could work together to provide a nearly equal axial load-bearing capability as the original column, and the construction material and cost would not be significantly changed. However, the control effectiveness of the SCIC system reduces when the system supports a very large superstructure [35]. To overcome this drawback, the authors further proposed a pendulum-type CIC system (PCIC, Fig. 1(f)) [42], in which the sliding-type interior column of the SCIC system was modified into a pendulum TMD (PTMD). In other words, instead of using the sliding device at each end of the interior column in the SCIC system, a roller and a hinge were installed on the bottom and the top of the interior column, respectively, for the connection with the exterior column. Without compromising the load-bearing capability of the column, the pendulum-type interior column could rotate inside the exterior column acting as a PTMD to attenuate the adverse vibration of the structures under earthquake excitations. As presented in Ref. [42], the design formulae were derived for calculating the optimum parameters of the PCIC system and the results obtained from sensitivity analyses and numerical simulations both demonstrated that the PCIC system showed a better control performance and robustness than the SCIC system for structural vibration mitigation. This study extends the previous research [42], adopting the PCIC system as the bridge pier for seismic response mitigation of bridge structures.It should be noted that the present study only investigates the influences of the SVGMs on the PCIC pier-supported bridges. The soil-structure interaction (SSI) is not considered in this paper so as to more clearly evaluate the effect of the SVGM on the seismic responses of bridges supported by PCIC piers. The SSI would also affect structural responses, which have been well revealed in many published articles (e.g. Refs. [ 66–70]). The influences of the SSI on the seismic responses of bridge structures supported by PCIC piers will be further investigated and clarified in the future. Moreover, shaking table tests are going to be carried out in the near future to further demonstrate the control effectiveness of the PCIC system in mitigating seismic induced vibrations. Publisher Copyright: {\textcopyright} 2022 Elsevier Ltd",
year = "2023",
month = jan,
doi = "10.1016/j.soildyn.2022.107594",
language = "English",
volume = "164",
journal = "Soil Dynamics and Earthquake Engineering",
issn = "0267-7261",
publisher = "Elsevier BV",
}