基于材料性能劣化的RC框架结构抗震性能评估及易损性分析

为了提高钢筋混凝土(reinforced concrete, RC)框架结构的使用寿命，明晰长期服役后的材料劣化对结构抗震性能和易损性的影响程度，建立了考虑材料性能劣化的RC框架结构的有限元分析模型。选取材料性能未劣化(100%)以及分别劣化至90%,80%和70%时的4种工况(依次表示为flsc-100,flsc-90,flsc-80和flsc-70)进行抗震性能评估，同时绘制地震易损性曲线，并分析其在不同地震强度作用下的易损性。结果表明：1)随着材料劣化程度的加剧，RC框架结构在不同地震波下的抗震性能明显降低。罕遇地震作用下，flsc-70的层间位移角比flsc-100增大了80%;2)随着结构刚度及承载力的降低，RC框架结构在不同破坏状态下的超越概率均有显著提升。罕遇地震作用下，flsc-90,flsc-80和flsc-70发生严重破坏的超越概率比flsc-100分别增大了75%,300%和975%。因此，在既有结构抗震性能评估中考虑材料性能劣化的影响十分必要。研究结果可以帮助预测材料性能劣化的RC框架结构在地震发生时的损伤程度，为结构的加固及修复提供参考依据。

Seismic performance evaluation and vulnerability analysis of

In order to improve the service life of reinforced concrete (RC) frame structures, a finite element analysis model of RC frame structures considering material degradation was established to clarify the influence degree of material degradation on seismic performance and vulnerability of RC frame structures after long-term service. Four scenarios based on the deteriorations of material performance at 100%, 90%, 80%, and 70% (denoted as flsc-100, flsc-90, flsc-80, and flsc-70, respectively) were selected seismic performance. Simultaneously, seismic fragility curves were plotted to analyze the vulnerability of the structure under different levels of seismic intensity.The results show that: 1) The seismic performance of RC frame structures under different seismic waves decreases obviously with the increase of the deterioration degree of materials. Under rare earthquake action, the interlayer displacement angle of flsc-70 increases by 80% compared with flsc-100. 2) With the decrease of structural stiffness and bearing capacity, the exceedance probability of RC frame structures under different failure states is significantly increased. The exceedance probability of serious damage in flsc-90, flsc-80 and flsc-70 increased by 75%, 300% and 975%, respectively, compared with flsc-100. Therefore, it is necessary to consider the effect of material degradation in the seismic performance evaluation of existing structures. The research results can help predict the damage degree of RC frame structures with deteriorating material properties during earthquake, and provide a reference for structural reinforcement and repair.