单索面固结体系斜拉桥在非一致激励下的地震响应
|
摘要
基于非平稳随机地震动场理论,研究地震动空间变化对单索面固结体系斜拉桥地震响应特征的影响。建立非一致激励功率谱模型,根据大桥地质勘查资料和区域地震标准分别合成主塔、桥墩桩基基底的非一致地震波。运用在基底处增加大质量质块的方法,将地震加速度转化为地震力,实现对单索面固结体系斜拉桥的多点激励。分析结果表明,与一致地震激励相比,非一致激励下的桥梁位移与内力均可有数量级的增大,并且不会出现塔顶相对水平位移和塔根截面弯矩减小的现象。因此,对于单索面固结体系斜拉桥,不考虑非一致激励的抗震分析是偏不安全的,地震动空间变化造成的影响必须予以足够的重视。
Based on non-stationary random theory of earthquake motion field,the response characteristics of single-plane cable-stayed rigid frame bridge were analyzed with respect to the spatial variability effects of ground motion.Non-uniform earthquake waves on the bottoms of main tower base were composted with nonuniform excitation power spectrum model based on geological exploration data of bridges and earthquake standards.Through increasing basal mass block of great quality at the basement,earthquake acceleration will be converted into earthquake force,which can bring about the multi-point excitation on the single-plane cable-stayed rigid frame bridge.The analysis results reveal that the bridge displacement and internal force caused by non-uniform excitation can be increased by magnitudes compared with the same seismic excitation,and the reduction of the relative horizontal displacement on top of the tower and the cross-section moment at the root of the tower don't come out.Therefore,as for this bridge-type,it tends to be unsafe for the seismic analysis without considering about the nonuniform excitation.Hence,the results suggest that great attention should be attached to the impact caused by spatial variation of ground motion.
Based on non-stationary random theory of earthquake motion field,the response characteristics of single-plane cable-stayed rigid frame bridge were analyzed with respect to the spatial variability effects of ground motion.Non-uniform earthquake waves on the bottoms of main tower base were composted with nonuniform excitation power spectrum model based on geological exploration data of bridges and earthquake standards.Through increasing basal mass block of great quality at the basement,earthquake acceleration will be converted into earthquake force,which can bring about the multi-point excitation on the single-plane cable-stayed rigid frame bridge.The analysis results reveal that the bridge displacement and internal force caused by non-uniform excitation can be increased by magnitudes compared with the same seismic excitation,and the reduction of the relative horizontal displacement on top of the tower and the cross-section moment at the root of the tower don't come out.Therefore,as for this bridge-type,it tends to be unsafe for the seismic analysis without considering about the nonuniform excitation.Hence,the results suggest that great attention should be attached to the impact caused by spatial variation of ground motion.
引文
[1]秦权,孙晓燕,贺瑞,等.苏通桥对非一致地震地面运动的反应和人工波质量的讨论[J].工程力学,2006,23(9):71-83,188.
[2]刘洪兵,朱日希.大跨度斜拉桥多支承激励地震响应分析[J].土木工程学报,2001,34(6):38-44.
[3]范立础,王君杰,陈玮.非一致地震激励下大跨度斜拉桥的响应特征[J].计算力学学报,2001,18(3):38-44.
[4]张翠红.大跨度斜拉桥多点激励效应研究[D].南京:东南大学,2004.
[5]项海帆.斜张桥在行波作用下的地震反应分析[J].同济大学学报,1983(2):1-9.
[6]陈幼平,周宏业.斜拉桥地震反应的行波效应[J].土木工程学报,1996,29(6):61-68.
[7]Nazmy A S,Abdel-Ghaffar A M.Effects of Ground Motion Spatial Variability on the Response of Cable-stayed Bridges[J].Earthquake Engineering and Structural Dynamics,1992,21(1):1-20.
[8]Kiureghian A D,Neuenhofer A.Response Spectrum Method for Multi-support Seismic Excitations[J].Earthquake Engineeringand Structural Dynamics,1992,21(8):713-740.
[9]李宏男.结构多维抗震理论设计方法[M].北京:科学出版社,1998.
[2]刘洪兵,朱日希.大跨度斜拉桥多支承激励地震响应分析[J].土木工程学报,2001,34(6):38-44.
[3]范立础,王君杰,陈玮.非一致地震激励下大跨度斜拉桥的响应特征[J].计算力学学报,2001,18(3):38-44.
[4]张翠红.大跨度斜拉桥多点激励效应研究[D].南京:东南大学,2004.
[5]项海帆.斜张桥在行波作用下的地震反应分析[J].同济大学学报,1983(2):1-9.
[6]陈幼平,周宏业.斜拉桥地震反应的行波效应[J].土木工程学报,1996,29(6):61-68.
[7]Nazmy A S,Abdel-Ghaffar A M.Effects of Ground Motion Spatial Variability on the Response of Cable-stayed Bridges[J].Earthquake Engineering and Structural Dynamics,1992,21(1):1-20.
[8]Kiureghian A D,Neuenhofer A.Response Spectrum Method for Multi-support Seismic Excitations[J].Earthquake Engineeringand Structural Dynamics,1992,21(8):713-740.
[9]李宏男.结构多维抗震理论设计方法[M].北京:科学出版社,1998.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心