基于性能的钢框架结构地震易损性分析

Performance-based Seismic Fragility Analysis of Steel Frame Structures

结合我国2010版抗震规范,根据结构极限状态定义结构整体地震需求参数的损伤状态极限限值和性能水平,提出基于性能的有效评估结构抗震性能的易损性分析方法。以一钢框架结构为例,考虑地震动输入的不确定性,基于增量动力分析(IDA)获得结构地震需求参数与地震动强度指标之间的关系,回归最大层间位移角与地震动峰值加速度的对数函数关系式,得到结构的易损性曲线,由此确定结构在不同地震作用下处于不同性能水平下的失效概率。并与传统的破坏标准的地震易损性分析结果进行比较,结果表明:不同破坏标准下易损性分析结果不同;规范的各种破坏状态偏于保守;在大震作用下,结构倒塌风险小。为钢框架结构抗震设计、地震灾害损失评估和未来地震的损失预测提供参考依据。

Combined with the specified limits of performance levels, based on the performance-based fragility analysis method, ultimate damage states and performance level limits of seismic demand parameters for entire structure are proposed according to the ultimate damage states of the structures based on 2010 seismic code. Considering the randomness of input ground motions, a method for solving the limit values of the four performance levels is put forward. Based on the results of incremental dynamic analysis （IDA） , the relationship between the two seismic demand parameters and ground motion intensity indicators is obtained. The performance-based seismic fragility analysis is carried out by this method, and fragility curves are derived to assess and compare the seismic performances under different IM parameters and different ground motions. According to the actual seismic demand of the structure, it can determine the damage states from the sense of probability, and provide a reference for future seismic damage prediction.