This study presents a seismic fragility assessment methodology incorporating the cumulative damage effects of repeated seismic loading on structures. Conventional seismic fragility assessment methods typically focus on single earthquakes across multiple structures; however, seismic events often occur in sequences, with each event adding cumulative damage that can amplify the overall damage. Ignoring the effects of repeated earthquakes in fragility assessments may lead to underestimating seismic risk. This study proposes a simplified but efficient fragility assessment method that accounts for repeated earthquake effects using probabilistic combinations of each damage state. This procedure applied the capacity spectrum method to consider capacity degradation from displacement caused by prior earthquakes. Applying various earthquake scenarios, this study analyzes the effects of damage accumulation from earthquake occurrence sequences, structural behavior types, and seismic design levels on the fragility of structures under repeated earthquake events.

A B S T R A C T
1. 서 론
2. 반복지진취약도
    2.1 지진취약도곡선
    2.2 구조 유형
    2.3 내진설계 수준
    2.4 단일지진 손상확률
    2.5 반복지진 손상확률
3. 역량스펙트럼법
    3.1 요구스펙트럼
    3.2 역량곡선
    3.3 수정역량곡선
    3.4 구조물 비선형성
    3.5 역량스펙트럼법을 이용한 구조물 응답 산정
    3.6 구조물 손상을 반영한 응답 산정
    3.7 반복지진취약도 산정
4. 지진 시나리오별 지진취약도
    4.1 반복지진 고려 영향
    4.2 지진발생순서 영향
    4.3 구조물 거동 유형과 내진설계 수준 선택 영향
5. 결 론
감사의 글
REFERENCES

• 변영준(부산대학교 사회환경시스템공학과 석사과정) | Byun Young Jun (Masteral Student, Department of Civil Engineering, Pusan National University)
• 김시영(부산대학교 사회환경시스템공학과 박사과정) | Kim Si Young (Ph. D Student, Department of Civil Engineering, Pusan National University)
• 김정한(부산대학교 사회환경시스템공학과 부교수) | Kim Jung Han (Associate Professor, Department of Civil Engineering, Pusan National University) Corresponding author