长持时地震作用下多层框架结构的抗倒塌性能评估

Assessment on the anti-collapse performance of multi-story frame structure under long duration earthquakes

依据"等效频谱"的原则筛选出86组频谱匹配的长持时和短持时强震记录,建立了考虑结构强度刚度退化和P-Δ效应的精细化结构模型。通过IDA分析和易损性分析,系统评估了长持时和短持时地震作用下框架结构的平均抗倒塌能力。结果表明:在地震振幅和频谱接近的条件下,传统选择的短持时地震记录会明显高估结构的抗倒塌能力;同时持时不仅对结构的累计损伤有影响,而且对结构的峰值变形(如最大层间位移角)也会产生不可忽略的影响。

Based on the principle of "equivalent spectrum", 86 sets of long and short duration strong earthquake records are selected through the spectrum matching. The refined structural model is constructed considering the strength degradation, stiffness degradation and P-Δ effect. Through the IDA and seismic vulnerability analysis, the anti-collapse capacity of the frame structure is assessed systematically under the long and short duration records, respectively. The results show that the traditional short duration earthquake records could significantly overestimate the anti-collapse capacity of the structure under the similar amplitude and spectrum;Meanwhile, the duration not only influences the cumulative damage of the structure, but also the peak deformation (such as the maximum story drift angle) of the structure.