【摘要】 为研究斜拉-悬吊协作体系桥的抗震性能,以一座主跨1 400m的斜拉-悬吊协作体系桥方案为背景进行分析。采用MIDAS Civil建立桥梁三维有限元模型,采用地震反应谱和时程分析方法进行水平和竖向地震作用下结构的地震反应分析以及结构非线性对地震反应的影响分析,并通过与相同主跨悬索桥和斜拉桥方案地震反应的对比,探讨斜拉-悬吊协作体系桥在超大跨度桥梁中的适用性。结果表明:在水平地震作用下,斜拉-悬吊协作体系桥塔、梁结合处的主梁和塔柱以及塔底截面产生最大内力,应重视这些关键截面的抗震设计;斜拉-悬吊协作体系桥的抗震性能介于斜拉桥与悬索桥之间,更偏向于悬索桥,比斜拉桥优越,适用于主跨超千米的大跨度桥梁。更多还原

【Abstract】 To study the seismic performance of the combined cable-stayed and suspension bridge,aproposed bridge of the same kind with a main span of 1 400 m was taken as an example and was analyzed.The three-dimensional finite element model for the bridge was set up by the MIDAS Civil,the structural seismic responses of the bridge under the horizontal and vertical seismic action and the influence of the structural nonlinearity on the seismic responses were analyzed by the seismic response spectrum and the time-history analysis methods.Through comparison of the seismic responses of the bridge to those of a suspension bridge and a cable-stayed bridge having the same main spans,the adaptability that the bridge was to be used as the super long span bridge was studied.The results of the study show that under the horizontal seismic action,the greatest internal forces may occur in the main girder at the connections of the towers and girder and in the cross sections of the tower columns and tower footings of the bridge and therefore,special attention should be paid to the seismic design of these critical locations and cross sections.The seismic performance of the bridge is between that of the cabled-stayed bridge and suspension bridge,is closer to that of the suspension bridge,is superior to that of the cable-stayed bridge and is applicable to the long span bridge having span length over 1 000 m.更多还原