【摘要】 传统的地震倒塌易损性分析中通常只考虑地震动不确定性的影响。在结构临近倒塌时,通常处于高度非线性状态,会出现结构不确定性与地震动不确定性的耦合放大现象。针对这一问题,将平均值一次二阶矩方法(MVFOSM)与逐步增量动力分析(IDA)相结合,提出了一种可以考虑结构不确定性的基于MVFOSM的随机IDA方法。以五层三跨钢筋混凝土框架结构为例,采用基于MVFOSM的随机IDA方法对其进行了地震倒塌易损性分析,并利用"龙卷风图"方法对结构抗地震倒塌能力的灵敏度进行了分析。研究表明:结构不确定性的存在使得结构抗地震倒塌能力的对数标准差增加了70%,因此有必要在地震倒塌易损性分析中考虑结构不确定性的影响。更多还原

【Abstract】 In general,conventional seismic collapse fragility only incorporates the uncertainties in earthquakes.When a structure is near to collapse,it will illustrate highly nonlinear behavior.Structural nonlinearity may be then coupled with structural uncertainty,resulting in magnified influences on structural seismic collapse capacity.This study presents a MVFOSM-based(mean value first order second moment) random IDA(incremental dynamic analysis) approach,which combines the MVFOSM with IDA.A five-story and three-bay RC frame structure designed according to Chinese codes was used to conduct seismic collapse fragility analysis using the proposed MVFOSM-based random IDA approach.The sensitivities of the considered structural random parameters were illustrated through ‘tornado diagram’.The results show that the standard deviation of the seismic collapse capacity is increased by 70 percent due to structural uncertainties.Therefore,it’s reasonable to consider structural uncertainty in seismic collapse fragility analysis.更多还原