多维性能极限状态下基于模糊失效准则的结构概率地震风险分析

Structure probabilistic seismic risk analysis based on fuzzy failure criteria under multidimensional performance limit states

考虑了结构多维性能极限状态的模糊不确定性,建立基于模糊失效准则的概率地震风险分析方法。综合考虑结构和非结构构件的抗震性能,建立多维性能极限状态方程。选择三种隶属函数描述极限状态的模糊性,包括降半梯形分布、降岭型分布和二次抛物型分布,基于地震烈度概率模型,建立基于模糊失效准则的概率地震风险分析表达式。基于SAP2000建立RC框剪结构模型进行分析。研究表明:基于二次抛物型分布的年平均超越概率会随着隶属区间的扩大而减小,而基于降半梯形分布和降岭型分布的年平均超越概率会随着隶属区间的扩大而增大;若隶属区间相同,三种隶属函数的年平均超越概率,从大到小依次为降半梯形分布、降岭型分布、二次抛物型分布;忽略不同工程需求参数性能极限状态的相关性会使年平均超越概率偏低。

A probabilistic seismic risk analysis method based on fuzzy failure criteria and multidimensional performance limit state is established.Three membership functions are selected,including half-trapezoidal distribution,descending-ridge distribution,and quadratic parabolic distribution.An integral formula for probabilistic seismic risk analysis is established.A RC frame-shear wall structure based on SAP2000 is established.The results show that the annual average transcendental probability based on the qua-dratic parabolic distribution decreases with the expansion of the membership interval,while the annual average transcendental prob-ability based on the halved trapezoidal distribution and the ridged distribution increases.Under the same membership interval,the annual mean transcendental probability of three membership functions is descending trapezoidal distribution,descending ridge distri-bution,and quadratic parabolic distribution in a descending order.If the correlation of the performance limit state under different en-gineering requirement parameters is ignored,the seismic risk probability will be lower.