Journal of the Earthquake Engineering Society of Korea (한국지진공학회논문집)

Earthquake Engineering Society of Korea (한국지진공학회)
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Considerations for the Generation of In-Structure Response Spectra in Seismically Isolated Structures

면진구조물 내 층응답스펙트럼 작성을 위한 고려사항

  • Lee, Seung Jae (Department of Civil Engineering, Pusan National University) ;
  • Kim, Jung Han (Department of Civil Engineering, Pusan National University)
  • 이승재 (부산대학교 토목공학과) ;
  • 김정한 (부산대학교 토목공학과)
  • Received : 2021.10.15
  • Accepted : 2022.02.04
  • Published : 2022.03.01
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Abstract

In order to evaluate the earthquake safety of equipment in structures, it is essential to analyze the In-Structure Response Spectrum (ISRS). The ISRS has a peak value at the frequency corresponding to the structural vibration mode, but the frequency and amplitude at the peak can vary because of many uncertain parameters. There are several seismic design criteria for ISRS peak-broadening for fixed base structures. However, there are no suggested criteria for constructing the design ISRS of seismically isolated structures. The ISRS of isolated structures may change due to the major uncertainty parameter of the isolator, which is the shear stiffness of the isolator and the several uncertainty parameters caused by the nonlinear behavior of isolators. This study evaluated the effects on the ISRS due to the initial stiffness of the bi-linear curve of isolators and the variation of effective stiffness by the input ground motion intensity and intense motion duration. Analyzing a simplified structural model for isolated base structure confirmed that the ISRS at the frequency of structural mode was amplified and shifted. It was found that the uncertainty of the initial stiffness of isolators significantly affects the shape of ISRS. The variation caused by the intensity and duration of input ground motions was also evaluated. These results suggested several considerations for generating ISRS for seismically isolated structures.

Keywords

Acknowledgement

이 논문은 2019년도 정부(교육부)의 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업(No. 2019R1I1A3A01058812) 및 산업통상자원부(MOTIE)와 한국에너지기술평가원(KETEP)의 지원을 받아 수행한 연구과제(No. 20181510102410)입니다.

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