Seismic Fragility Analysis of Multi-Modes Structures Considering Modal Contribution Factor

모드기여도를 고려한 복수모드구조물의 지진취약도분석

  • 조양희 (인천대학교 토목환경시스템공학과) ;
  • 조성국 (인천대학교 토목환경시스템공학과)
  • Published : 2002.08.01


In the course of seismic probabilistic risk assessment(SPRA), seismic fragility analysis(SFA) is utilized as a tool to evaluate the actual seismic capacity of structures. This paper introduces a methodology of SFA and its evaluation procedures, especially focusing on the basic fragility variables. A new definition of the response spectrum shape factor as one of the most critical basic variables is suggested. The new factor is expressed as a term of linear algebraic sum using the modal contribution factor. The efficiency of new response spectrum shape factor is evaluated and validated to use in practice through the case study of the nuclear power plant structures. The case study results show that the proposed method can be effectively applicable to multi-mode structures with composite modal damping.


probabilistic seismic risk assessment;seismic fragility analysis;basic variable;response spectrum shape factor;modal contribution factor


  1. Ravindra, M. K., “Seismic individual plant examination of external events of US nuclear power plants: insights and implications,” J. Nuclear Engineering and Design, Vol. 175, 1997, pp. 227-236.
  2. Kennedy, R. P. et. al., “Probabilistic seismic safety study of an existing nuclear power plant,” Nuclear Engineering and Design, Vol. 59, 1980, pp. 315-338.
  3. USNRC, “Individual plant examination of external events (IPEEE) for severe accident vulnerabilities,” Generic Letter No. 88-20, Supplement 4, US Nuclear Regulatory Commission, 1991.
  4. Wilson, E. L., Three Dimensional Dynamic Analysis of Structures with Emphasis on Earthquake Engineering, Computers and Structures, Inc., Berkeley, California, 1997.
  5. Reed J. W. and Kennedy, R. P., “Methodology for developing seismic fragilities”, EPRI TR-103959, Electric Power Research Institute, Palo Alto, California, 1994.
  6. Ravindra, M. K., “Seismic probabilistic risk assessment and its impaction on margin studies,” J. Nuclear Engineering and Design, Vol. 107, 1988, pp. 51-59.
  7. 윤철호, “지진손상특성을 고려한 원전구조물의 취약도 해석”, 박사학위논문, 서울대학교, 1994.
  8. Chopra, A. K., “Modal analysis of linear dynamic systems : Physical interpretation,” J. Structural Engineering, ASCE, Vol. 122, No. 5, 1996, pp. 517-527.
  9. 이성노, “철근콘크리트 구조물의 지진손상평가 및 취약도해석”, 박사학위논문, 서울대학교, 1992.
  10. Kennedy R. P. and Ravindra, M. K., “Seismic fragilities for nuclear power plant risk studies,” J. Nuclear Engineering and Design, Vol. 79, No. 1, 1984, pp. 47-68.
  11. USNRC, “Procedural and submittal guidance for the individual plant examination of external events(IPEEE) for severe accident vulnerabilities,” NUREG-1407, US Nuclear Regulatory Commission, 1991.
  12. 조양희등, “원자력발전소의 지진안전성평가를 위한 지진 취약도분석”, 기술개발 최종보고서, KOPEC/90-T-004, 한국전력기술주식회사, 1990.
  13. Lee, N. H. and Song, K. B., “Seismic capability evaluation of the prestressed/reinforced concrete containment, Younggwang nuclear power plant units 5 & 6,” J. Nuclear Engineering and Design, Vol. 192, 1999, pp. 189-203.
  14. KOPEC, “Yonggwang Units 5 and 6 Containment Design Report,” No. 9-310-C460-003, Korea Power Engineering Company, 1999.
  15. USNRC, “Design response spectra for nuclear power plants,” Regulatory Guide 1.60, Rev. 1, U.S. Nuclear Regulatory Commission, 1973.
  16. USNRC, “PRA procedures guide - A guide to the performance of probabilistic risk assessments for nuclear power plants,” Final Report, Vol. I & Vol. II, NUREG/CR-2300, US Nuclear Regulatory Commission, 1982.
  17. 조성국, 조양희, 박형기, 황규호, “복합모드감쇠를 고려한 구조물의 지진취약도분석”, 2001년도 추계 한국지진공학회 학술발표회 논문집, Vol. 5, No. 2, 2001. 9, pp. 200-207.
  18. Newmark, N. M. and Hall, W. J., “Development of criteria for seismic review of selected nuclear power plants,” NUREG/CR-0098, 1978.
  19. 조양희, 박형기, 조성국, “핵심 구조물의 확률론적 지진 취약도 분석 : 기술현황”, 2000년 춘계 한국지진공학회 학술발표회 논문집, 2000. 3, pp. 226-232.