高速铁路梁桥建模参数敏感性分析  

Sensitivity analysis of modeling parameters of high-speed railway girder bridges

作　　者：胡章亮 魏标[1,2] 蒋丽忠 李姗姗[1,2] HU Zhangliang;WEI Biao;JIANG Lizhong;LI Shanshan(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center of High-speed Railway Construction Technology,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]高速铁路建造技术国家工程研究中心,湖南长沙410075

出　　处：《铁道科学与工程学报》2023年第2期393-404,共12页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51778635,U1934207,51978667)。

摘　　要：平衡模型建立效率和确保模型计算结果的准确性一直以来都是高速铁路梁桥概率地震需求分析所面临的挑战。鉴此,首先,以典型高速铁路简支梁桥和连续梁桥为工程背景,罗列建模相关不确定性参数及其概率分布;其次,采用分式析因设计方法,基于OpenSees建立的有限元模型生成了32组考虑15种建模不确定性参数的计算工况;最后,通过方差分析得到的p值确定不同建模参数对构件地震响应的影响程度,从而筛选出高速铁路梁桥建模时需考虑的重要参数。分析结果表明:不同构件地震响应对建模参数的敏感性差异明显,但地震波加载方向、支座摩擦因数、混凝土密度和结构阻尼比这4个建模参数以及混凝土弹性模量和混凝土抗压强度的交互作用均显著影响2种梁桥的地震响应,在进行高速铁路梁桥概率地震需求分析时不可忽略;简支梁桥和连续梁桥在建模时还应分别关注滑动层初始刚度和桩基础平动刚度的不确定性。在高速铁路梁桥概率地震需求分析中考虑重要建模参数的不确定性,可以在确保构件地震响应预测准确的同时提升建模效率。Balancing the efficiency of simulation and ensuring the accuracy of model calculation results has always been a challenge for probabilistic seismic demand analysis(PSDA) of high-speed railway girder bridges(HRGBs). Therefore, by taking the typical high-speed railway simply supported girder bridge and continuous girder bridge as the engineering background, the uncertain parameters and their probability distribution related to the modeling were collected. Subsequently, based on the finite element model established by OpenSees, 32groups of calculation cases considering 15 modeling uncertainty parameters were generated by employing the fractional factorial design method. The influence of different modeling parameters on the seismic response of components was then determined through the p value in terms of variance analysis. The results indicate that the sensitivity of different component responses to modeling parameters is obviously different, with the four parameters, including the inducing direction of ground motions, the friction coefficient of bearings, concrete density and structural damping ratio, as well as the interaction of concrete elastic modulus and concrete compressive strength, all significantly affecting the seismic responses and thus not being able to be ignored in the PSDA of HRGBs. Additionally, the uncertainties of the initial stiffness of the sliding layers and the translational stiffness of the pile foundation should also be paid attention to in the modeling of the simply supported girder bridges and the continuous girder bridges. Considering the uncertainty of important modeling parameters in the PSDA of HRGBs can not only ensure the accuracy of seismic response prediction, but also improve the modeling efficiency.

关 键 词：高速铁路梁桥 建模参数 分式析因设计 地震响应 方差分析 概率地震需求分析 

分 类 号：U24[交通运输工程—道路与铁道工程]