近断层地震作用下RC框排架结构易损性研究

Seismic Vulnerability Analysis of RC Frame-Bent Structures Subjected to Near-fault Ground Motions

摘要:

为研究近断层地震作用下框排架结构破坏的可能性，以某钢筋混凝土框排架结构为原型建立有限元非线性分析模型，选取16条近断层地震波及8条远场地震波，采用增量动力分析方法绘制易损性曲线。结果表明：对于远场地震，8度多遇地震及基本地震时，结构正常使用、基本使用、修复后使用、生命安全及防止倒塌五个极限状态均未超越，满足"小震不坏，中震可修"的抗震要求；8度罕遇地震时，仅超越正常使用极限状态的概率为2.08%，满足"大震不倒"的抗震要求。而近断层地震时，在8度多遇地震时结构前四个极限状态均被超越，基本地震时结构超过修复后使用的极限状态概率为16.62%，有2.40%的概率达到生命安全的极限状态，罕遇地震时接近倒塌的概率为15.4%。研究结果可为近断层地区框排架结构地震风险评估提供参考。

Abstract:

To study the failure possibility of frame-bent structures under near-fault earthquake, the nonlinear finite element analysis model was established based on a reinforced concrete frame-bent structure. 16 near-fault and 8 far-field seismic waves were selected, and the incremental dynamic analysis method was used to draw the vulnerability curves. The results showed that for far-field ground motions, five limit states of the structure (normal use, basic use, use after repair, life safety, and collapse prevention) are not beyond under 8-degree frequent and basic earthquakes, thus meeting the seismic requirement of "no damage under minor earthquake, repairable under moderate earthquake"; the probability of exceeding limit state of normal use under 8-degree rare earthquake is 2.08%, thus meeting the seismic requirement of "no collapse under major earthquake". For near-fault ground motions, the first four limit states are exceeded under 8-degree frequent earthquake; under 8-degree basic earthquake, the probability of exceeding the limit state of use after repair is 16.62%, and the probability of reaching the limit state of life safety is 2.40%; the probability of approaching collapse under 8-degree rare earthquake is 15.4%. The research results can provide reference for seismic risk assessment of frame-bent structures in near-fault area.