| 引用本文: | 张鹏辉,郭军军,冯睿为,袁万城.连续梁桥的矢量地震动强度指标选取[J].哈尔滨工业大学学报,2020,52(3):68.DOI:10.11918/201812166 |
| ZHANG Penghui,GUO Junjun,FENG Ruiwei,YUAN Wancheng.Selection of vector-valued ground motion intensity measures for continuous girder bridges[J].Journal of Harbin Institute of Technology,2020,52(3):68.DOI:10.11918/201812166 |
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| 摘要: |
| 为了在不显著增加计算量的前提下,简化地震动强度指标的选取流程,减小概率地震需求模型的变异性,提出针对特定场地条件和结构类型的矢量地震动强度指标选取方法. 首先基于候选的20个标量地震动强度指标（IM）,通过方差扩大因子法剔除能被其他IM线性表示的不重要IM,消除IM间的多重共线性；然后从线性无关的IM中按偏决定系数选取与工程需求参数具有显著相关性的IM作为矢量地震动强度指标的分量；同时以邯郸市南环路东延的一座预应力混凝土三跨连续梁桥为例,进行6折交叉验证. 结果表明:在训练数据集和测试数据集上,采用两步筛选后得到的矢量地震动强度指标[Sa0.2,Sa1.0,Tm]建立回归模型的离散性较采用标量地震动强度指标Sa1.0建立的回归模型分别减小13.67%、17.07%,且不存在过拟合现象. 研究结果可以为特定场地条件下的连续梁桥选取合适的矢量地震动强度指标. |
| 关键词: 矢量地震动强度指标 回归分析 多重共线性 方差扩大因子 偏决定系数 |
| DOI：10.11918/201812166 |
| 分类号:P315.9 |
| 文献标识码:A |
| 基金项目:国家自然科学基金(9,1) |
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| Selection of vector-valued ground motion intensity measures for continuous girder bridges |
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ZHANG Penghui,GUO Junjun,FENG Ruiwei,YUAN Wancheng
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(State Key Laboratory of Disaster Reduction in Civil Engineering (Tongji University), Shanghai 200092, China)
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| Abstract: |
| To simplify the process of selecting ground motion intensity measures and further reduce the variability of probability seismic demand models without significantly increasing computational cost, a vector-valued intensity measure selection model for specific site conditions and structure types was established. First, based on 20 scalar-valued intensity measures (IMs) candidates, the variance inflation factor method was used to eliminate the unimportant IM which can be linearly represented by other IMs, thereby eliminating the collinearity among IMs. Then, non-collinearity IMs which have significant correlation with engineering demand parameters were picked out as components of vector-valued intensity measure based on partial determination coefficient. Meanwhile, a three-span prestressed concrete continuous girder bridge, located on the east Nanhuan Road of Handan city, was taken as an example to verify the validity of the proposed method. Results of 6-fold cross-validation show that the variability of the regression model established by vector-valued IM [Sa(0.2),Sa(1.0),Tm] on training dataset and test dataset was reduced by 13.67% and 17.07% respectively, compared with the regression model established by scalar-valued IM[Sa(1.0)], and no overfitting phenomenon was observed. The research results can be utilized to select appropriate vector-valued intensity measures for continuous girder bridges under specific site conditions. |
| Key words: vector-valued ground motion intensity measure regression analysis collinearity variance inflation factor partial determination coefficient |
