主塔基础形式对超大跨斜拉桥抗震性能的影响
|
摘要
以泰州过江超大跨斜拉桥为例,就主塔分别采用高桩承台基础和沉井基础两种形式,对比研究桩基础大质量承台参与结构高阶水平向振型的质量参与系数分布、周期分布等特点,输入人工地震动参数,针对两种主塔基础方案采用线性时程分析方法计算桥梁结构控制部位地震反应并进行比较,再就桩基础方案中大质量承台对承台底水平反力的贡献进行时域和频域分析。研究表明,与沉井基础相比,主塔桩基础大质量承台参与结构高阶振动对超大跨斜拉桥动力特性和地震反应有重要影响,特别对主塔基础水平反力有显著的倍增效应,增大了超大跨斜拉桥的地震易损性。
Based on a super-span cable-stayed bridge over Yangtze River,which is planned with two optional pylon foundation forms: caisson and pile,modal participating mass ratio distribution and modal period distribution of free structural vibration modes involving distinct horizontal participation of the under-pylon huge-mass pile caps are studied by contrast.Artificial ground motions are applied in linear time-history analysis to calculate the controlling seismic responses of the bridge structure with caisson-form pylon foundations and alternative pile-form ones,then the results of the two cases are compared at the same structural locations;and in the horizontal directions the contribution of the under-pylon huge-mass pile caps to the cap bottom seismic reactions are analyzed in time domain as well as frequency domain.The research indicates that participation of the under-pylon huge-mass pile caps in high-order structural vibration modes essentially influences the dynamic properties and seismic responses of the super-span cable-stayed bridge,and sharply magnifies the horizontal seismic foundation reactions at the pylon cap bottoms compared with the case of caisson-form pylons foundations,which increases the seismic vulnerability of the super-span cable-stayed bridge.
Based on a super-span cable-stayed bridge over Yangtze River,which is planned with two optional pylon foundation forms: caisson and pile,modal participating mass ratio distribution and modal period distribution of free structural vibration modes involving distinct horizontal participation of the under-pylon huge-mass pile caps are studied by contrast.Artificial ground motions are applied in linear time-history analysis to calculate the controlling seismic responses of the bridge structure with caisson-form pylon foundations and alternative pile-form ones,then the results of the two cases are compared at the same structural locations;and in the horizontal directions the contribution of the under-pylon huge-mass pile caps to the cap bottom seismic reactions are analyzed in time domain as well as frequency domain.The research indicates that participation of the under-pylon huge-mass pile caps in high-order structural vibration modes essentially influences the dynamic properties and seismic responses of the super-span cable-stayed bridge,and sharply magnifies the horizontal seismic foundation reactions at the pylon cap bottoms compared with the case of caisson-form pylons foundations,which increases the seismic vulnerability of the super-span cable-stayed bridge.
引文
[1]闫冬,袁万城.大跨度斜拉桥的抗震概念设计[J].同济大学学报,2004,32(10):1344-1348.
[2]叶爱君,胡世德,范立础.超大跨度斜拉桥的地震位移控制[J].土木工程学报,2004,37(12):38-43.
[3]叶爱君,范立础.附加阻尼器对超大跨度斜拉桥的减震效果[J].同济大学学报,2006,34(7):859-863.
[4]梁智垚,李建中.大跨度公铁两用斜拉桥阻尼器参数研究[J].同济大学学报,2007,35(6):728-733.
[5]叶爱君,胡世德,范立础.斜拉桥抗震结构体系研究[J].桥梁建设,2004(4):1-4.
[6]邹立华,赵人达,陈兴冲.桩-土-独塔斜拉桥相互作用地震响应分析[J].计算力学学报,2006,23(2):242-246.
[7]宋晓辉,邓凡,刘建达.斜拉桥动力反应桩基础影响分析[J].山西建筑,2007,33(5):266-267.
[8]JTJ 024—85,公路桥涵地基与基础设计规范[S].
[9]Wilson E L.Three Dimensional Static and Dynamic Anal-ysis of Structures:a Physical Approach with Emphasis onEarthquake Engineering(4thEdition)[M].Berkley,Cali-fornia:Computers and Structures,Inc.,2002.
[10]胡聿贤.地震工程学(2版)[M].北京:地震出版社,2006.
[2]叶爱君,胡世德,范立础.超大跨度斜拉桥的地震位移控制[J].土木工程学报,2004,37(12):38-43.
[3]叶爱君,范立础.附加阻尼器对超大跨度斜拉桥的减震效果[J].同济大学学报,2006,34(7):859-863.
[4]梁智垚,李建中.大跨度公铁两用斜拉桥阻尼器参数研究[J].同济大学学报,2007,35(6):728-733.
[5]叶爱君,胡世德,范立础.斜拉桥抗震结构体系研究[J].桥梁建设,2004(4):1-4.
[6]邹立华,赵人达,陈兴冲.桩-土-独塔斜拉桥相互作用地震响应分析[J].计算力学学报,2006,23(2):242-246.
[7]宋晓辉,邓凡,刘建达.斜拉桥动力反应桩基础影响分析[J].山西建筑,2007,33(5):266-267.
[8]JTJ 024—85,公路桥涵地基与基础设计规范[S].
[9]Wilson E L.Three Dimensional Static and Dynamic Anal-ysis of Structures:a Physical Approach with Emphasis onEarthquake Engineering(4thEdition)[M].Berkley,Cali-fornia:Computers and Structures,Inc.,2002.
[10]胡聿贤.地震工程学(2版)[M].北京:地震出版社,2006.
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