Based on the multiple stripes analysis method,an investigation of the estimation of aleatory randomness by S_(a)(T_(1))-based intensity measures(IMs)in the fragility analysis is carried out for two typical low-and med...Based on the multiple stripes analysis method,an investigation of the estimation of aleatory randomness by S_(a)(T_(1))-based intensity measures(IMs)in the fragility analysis is carried out for two typical low-and mediumrise reinforced concrete(RC)frame structures with 4 and 8 stories,respectively.The sensitivity of the aleatory randomness estimated in fragility curves to various S_(a)(T_(1))-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 S_(a)(T_(1))-based IMs,considering the effect of softened period,can maintain lower record-to-record variability in the three limit states,and the S_(a)(T_(1))-based IMs,considering the effect of higher modes,do not show their advantage over S_(a)(T_(1)).Furthermore,the optimal multiplier C and exponentαin 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.展开更多
On the 2011 off the Pacific Coast of Tohoku Earthquake, gymnasium buildings exhibited the unexpected structural damages, which prevented a use as evacuation shelters in during- and post-disaster periods. The major fai...On the 2011 off the Pacific Coast of Tohoku Earthquake, gymnasium buildings exhibited the unexpected structural damages, which prevented a use as evacuation shelters in during- and post-disaster periods. The major failure occurr<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ing</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> on the connection between the RC column top and steel roof as well as the cracks in the RC column base w</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">as</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> observed during the emergent inspection. According to the earlier studies, it was implied that the presence of the slotted hole possibly deteriorates the seismic capacity;however, the length of slotted hole was fixed at a certain value. Facing this concern, this research attempts to clarify the influence of the slotted hole length through a comprehensive parametric study by pushover and seismic response analyses. In conclusion, it has been discovered that the slotted hole deteriorates the seismic capacity for the connection failure up to almost 50% of that without slotted hole. Moreover, the discrepancy of characteristics obtained by the static and dynamic analyses is originated by means of the presence of slotted hole. This slotted hole effect should be noted by structural engineers and researchers to provide the adequate seismic diagnosis and strengthening.</span></span></span>展开更多
基金the Jiangsu Youth Fund Projects(SBK2021044269)the National Natural Science Foundation of China Youth Fund(52108457,52108133)+4 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(20KJB560014)Fundamental Research Funds for the Central Universities(B210201019)High-level Talent Research Fund of Nanjing Forestry University(163050115)Nanjing Forestry University Undergraduate Innovation Training Program(2021NFUSPITP0221,2020NFUSPITP0352 and 2020NFUSPITP0373)Jiangsu Undergraduate Innovation Training Program(202110298079Y).
文摘Based on the multiple stripes analysis method,an investigation of the estimation of aleatory randomness by S_(a)(T_(1))-based intensity measures(IMs)in the fragility analysis is carried out for two typical low-and mediumrise reinforced concrete(RC)frame structures with 4 and 8 stories,respectively.The sensitivity of the aleatory randomness estimated in fragility curves to various S_(a)(T_(1))-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 S_(a)(T_(1))-based IMs,considering the effect of softened period,can maintain lower record-to-record variability in the three limit states,and the S_(a)(T_(1))-based IMs,considering the effect of higher modes,do not show their advantage over S_(a)(T_(1)).Furthermore,the optimal multiplier C and exponentαin 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.
文摘On the 2011 off the Pacific Coast of Tohoku Earthquake, gymnasium buildings exhibited the unexpected structural damages, which prevented a use as evacuation shelters in during- and post-disaster periods. The major failure occurr<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ing</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> on the connection between the RC column top and steel roof as well as the cracks in the RC column base w</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">as</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> observed during the emergent inspection. According to the earlier studies, it was implied that the presence of the slotted hole possibly deteriorates the seismic capacity;however, the length of slotted hole was fixed at a certain value. Facing this concern, this research attempts to clarify the influence of the slotted hole length through a comprehensive parametric study by pushover and seismic response analyses. In conclusion, it has been discovered that the slotted hole deteriorates the seismic capacity for the connection failure up to almost 50% of that without slotted hole. Moreover, the discrepancy of characteristics obtained by the static and dynamic analyses is originated by means of the presence of slotted hole. This slotted hole effect should be noted by structural engineers and researchers to provide the adequate seismic diagnosis and strengthening.</span></span></span>