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Title |
Development of a Cyclic Loading Protocol for RC Moment Frames based on Domestic Seismicity
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Authors |
김민성(Min-Seong Kim) ; 전나경(Na-Kyung Jeon) ; 김성현(Sung-Hyun Kim) ; 강수민(Su-Min Kang) |
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DOI |
https://doi.org/10.4334/JKCI.2026.38.4.549 |
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Keywords |
내진 성능; RC 모멘트골조; 주기 반복하중 프로토콜; 비선형 시간이력해석; 누적 손상 효과 seismic performance; RC moment frame; cyclic loading protocol; nonlinear time history analysis; cumulative damage effect |
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Abstract |
Conventional cyclic loading protocols (e.g., ACI 374.1 and FEMA 461) were developed based on earthquake records from high-seismic regions and therefore impose excessive cumulative damage demands when applied to structures in moderate-seismic regions such as Korea. In this study, 25 input ground motions were selected for Sc and Sd site conditions in each case while considering the shear wave velocity, magnitude, source-to-site distance, significant duration, and dominant frequency to reflect the short-period characteristics of Korean seismic environments. A total of 200 nonlinear time-history analyses (=25×2 site conditions×2 structural models×2 directions) were conducted for 3- and 5-story reinforced concrete moment frames using the selected ground motions. Repeated deformation cycles were extracted from the interstory drift responses of the critical floor through rainflow cycle counting. The cumulative damage characteristics of actual seismic responses were quantitatively evaluated using the Cumulative Distribution Function (CDF) and Cumulative Damage Effect (CDE), and loading protocols were developed based on these characteristics. Compared to the ACI 374.1 standard protocol, the proposed protocols required approximately 33?41 % (median), 53?67 % (84th percentile), and 91?116 % (98th percentile) of the cumulative damage effect. The 98th percentile protocols showed a cumulative damage demand comparable to that of ACI 374.1. The proposed protocol can provide an appropriate seismic performance evaluation method for reinforced concrete moment-resisting frames by reflecting the cumulative damage characteristics of actual seismic responses in Korea.
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