论文标题
改善概率的地震需求强度关系：异性恋方法
Improved probabilistic seismic demand-intensity relationship: heteroskedastic approachs
论文作者
论文摘要
作为评估结构的地震性能不可或缺的一部分，概率地震需求强度关系已得到广泛研究。在这项研究中，系统地研究了概率地震需求模型中异质性的现象。本文介绍了对异质性的定义，诊断和常规处理的简要回顾，并基于此，提出了两种对单变量和多元病例的更广泛的方法。对于典型的四跨跨度的吉尔德桥，通过多个条纹分析进行了一系列非线性时间历史分析，以确定其地震需求强度，可以用作样品集。对于单变量和多元病例，概率地震需求模型是根据贝叶斯回归框架下的上述两种方法开发的，并使用线性回归方法比较了拟合的结果并与常规模型进行了分析。在存在异质性的概率地震需求的情况下，可以有效地表征非恒定方差或协方差的模式，并且可以提供比同型模型更好的预测区域。彻底讨论了异质性现象和随后的解决方案的原因。分析程序可以进一步嵌入地震脆弱性和风险评估中，从而为无性抗害决策提供了更准确的基础。
As an integral part of assessing the seismic performance of structures, the probabilistic seismic demand-intensity relationship has been widely studied. In this study, the phenomenon of heteroscedasticity in probabilistic seismic demand models was systematically investigated. A brief review of the definition, diagnosis, and conventional treatment of heteroscedasticity is presented herein, and based on that, two more generalized methods for both univariate and multivariate cases are proposed. For a typical four-span simply supported girder bridge, a series of nonlinear time history analyses were performed through multiple stripe analysis to determine its seismic demand-intensity that can be employed as a sample set. For both univariate and multivariate cases, probabilistic seismic demand models were developed based on the two aforementioned methods under the Bayesian regression framework, and the fitted results were compared and analyzed with the conventional models using linear regression approaches. In the presence of probabilistic seismic demand considering heteroscedasticity, the patterns of non-constant variance or covariance can be characterized effectively, and a better-calibrated prediction region than that of homoscedastic models can be provided. The causes of the heteroscedasticity phenomenon and subsequent solutions are thoroughly discussed. The analysis procedures can be further embedded in seismic fragility and risk assessment, thus providing a more accurate basis for aseismic decision-making.
