不确定性参数对梁桥地震易损性影响的量化

为定量研究梁桥中常见的不确定性参数对结构地震易损性的影响程度,以三跨混凝土连续梁桥为例,引入重要性测度分析方法考虑不确定性参数之间的交互效应,量化不确定性参数对桥梁地震易损性的影响水平。通过Monte-Carlo抽样构建地震动-桥梁样本并采用Open Sees平台进行非线性时程分析,提出基于地震易损性的矩独立重要性测度指标并基于非参数核密度估计对其进行数值积分求解。结论:支座剪切模量及上部结构质量对梁桥地震易损性的影响明显大于其他参数;基于地震易损性的重要性测度指标能够考虑不确定性参数之间的交互效应,准确量化不确定性参数对梁桥地震易损性的影响水平。

Quantification of the Influence of Uncertain Parameters on the Seismic Fragility of Girder Bridges

A three-span concrete continuous girder bridge was used as an example to quantify the influence of uncertainties the seismic fragility of girder bridges. The importance measure analysis method was introduced to quantify the influence of uncertain parameters on the seismic fragility of the bridge and the interaction effect between uncertain parameters was considered. A series of ground motion-bridge probability samples were developed with Monte-Carlo sampling. The nonlinear time-history analysis was performed in the OpenSees platform. An independent moment-importance measure based on seismic fragility was proposed and calculated with numerical integration combining nonparametric kernel density estimation. The results show the influence of shear modulus of the bearing and superstructure mass on the seismic fragility of the bridge is obviously greater than other parameters. The importance measure based on seismic fragility accurately quantify the influence of uncertainty parameters on bridge seismic fragility by considering the interaction effect between parameters.