基于绝对位移法的曲线梁桥多维多点弹塑性随机响应分析  

Multidimensional and multipoint elastic-plastic stochastic response analysis of curved beam bridges based on the absolute displacement method

作　　者：李喜梅[1,2] 赵廷龙 陶铖 LI Ximei;ZHAO Tinglong;TAO Cheng(Western Engineering Research Center of Disaster Mitigation in Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Institute of Earthquake Protection and Disaster Mitigation,Lanzhou University of Technology,Lanzhou 730050,China;JOC Foreign Economic-Technical Cooperation Co.,Ltd.,Nanjing 210019,China)

机构地区：[1]兰州理工大学西部土木工程防灾减灾教育部工程研究中心,兰州730050 [2]兰州理工大学防震减灾研究所,兰州730050 [3]江苏海外集团对外经济技术合作有限公司,南京210019

出　　处：《振动与冲击》2024年第10期164-173,共10页Journal of Vibration and Shock

基　　金：国家自然科学基金(52268028)。

摘　　要：针对当前地震动空间效应下曲线梁桥地震反应分析多采用确定性激励输入且忽略桥梁非线性的情况,采用了多维多点非平稳随机激励对曲线连续梁桥进行弹塑性响应分析。建立非线性有限元模型并降维解耦非平稳地震动非平稳演化功率谱(energy power spectral density,EPSD)矩阵,采用绝对位移法对桥梁进行非线性时程分析。考虑不同视波速、场地条件、相干性以及平稳与非平稳地震激励,综合分析了曲线连续梁桥的随机响应及其频域特性和时域特性。结果表明,地震动空间效应和地震动的非平稳性对曲线梁桥随机响应影响很大,其中地震动空间效应对桥梁随机响应大小及其频域分布有显著影响,而非平稳性会对随机响应大小及其时变响应趋势产生重要影响。因此,在曲线连续梁桥抗震分析中需充分考虑地震动空间效应和地震动非平稳性,以避免错误估计桥梁抗震性能。提供了全面的分析结果,对加强曲线连续梁桥的抗震设计和评估,从而提高其抗震性能和可靠性具有重要意义。The seismic response analysis of curved continuous beam bridges considering the spatial effects of seismic motion often employs deterministic excitation inputs while neglecting the nonlinearity of the bridges.In this study,an elastic-plastic response analysis was conducted on curved continuous beam bridges under multidimensional and multipoint non-stationary random excitations.A nonlinear finite element model was established,and the nonstationary seismic motion’s energy power spectral density(EPSD)matrix was reduced and decoupled through dimensionality reduction.The nonlinear time history analysis of the bridges was carried out using the absolute displacement method.Different apparent wave velocities,site conditions,coherence,and stationary/non-stationary seismic excitations were considered to comprehensively analyze the random response,frequency-domain characteristics,and time-domain characteristics of the curved continuous beam bridges.The results indicate that the spatial effects and the non-stationarity of the seismic motion have a significant impact on the random response of the curved beam bridges.The spatial effects of seismic motion have a notable influence on the magnitude and frequency-domain distribution of the bridge’s random response,while the non-stationarity affects both the magnitude and the temporal response trend of the random response.Therefore,it is essential to fully consider the spatial effects and the non-stationarity of seismic motion in the seismic analysis of curved continuous beam bridges to avoid inaccurately estimating the seismic performance of the bridges.The comprehensive analysis results provided in this study are of great significance for strengthening the seismic design and evaluation of curved continuous beam bridges,thereby improving their seismic performance and reliability.

关 键 词：曲线连续梁桥 多维多点 虚拟激励法 非平稳激励 绝对位移 非线性 地震动空间效应 

分 类 号：TU352.1[建筑科学—结构工程] U441.3[建筑科学—桥梁与隧道工程]