TY  - EJOU
AU  - Zhang, Yantai 
AU  - Shi, Yongan 
AU  - Sun, Baoyin 
AU  - Wang, Zheng 

TI  - Estimation of Aleatory Randomness by <i>S</i><sub><i>a</i></sub>(<i>T</i><sub>1</sub>)-Based Intensity Measures in Fragility Analysis of Reinforced Concrete Frame Structures
T2  - Computer Modeling in Engineering \& Sciences

PY  - 2022
VL  - 130
IS  - 1
SN  - 1526-1506

AB  - Based on the multiple stripes analysis method, an investigation of the estimation of aleatory randomness by <i>S<sub>a</sub></i>(<i>T</i><sub>1</sub>)-based intensity measures (IMs) in the fragility analysis is carried out for two typical low- and medium-rise reinforced concrete (RC) frame structures with 4 and 8 stories, respectively. The sensitivity of the aleatory randomness estimated in fragility curves to various <i>S<sub>a</sub></i>(<i>T</i><sub>1</sub>)-based IMs is analyzed at three damage limit states, i.e., immediate occupancy, life safety, and collapse prevention. In addition, the effect of characterization methods of bidirectional ground motion intensity on the record-to-record variability is investigated. It is found that the damage limit state of the structure has an important influence on the applicability of the ground motion IM. The <i>S<sub>a</sub></i>(<i>T</i><sub>1</sub>)-based IMs, considering the effect of softened period, can maintain lower record-to-record variability in the three limit states, and the <i>S<sub>a</sub></i>(<i>T</i><sub>1</sub>)-based IMs, considering the effect of higher modes, do not show their advantage over <i>S<sub>a</sub></i>(<i>T</i><sub>1</sub>). Furthermore, the optimal multiplier <i>C</i> and exponent <i>α</i> in the dual-parameter ground motion IM are proposed to obtain a lower record-to-record variability in the fragility analysis of different damage limit state. Finally, the improved dual-parameter ground motion IM is applied in the risk assessment of the 8-story frame structure.
KW  - RC frame structure; intensity measure; fragility analysis; record-to-record variability; softened period; risk assessment

DO  - 10.32604/cmes.2022.016857