【摘要】 以一座大跨斜拉桥为工程背景,基于sap2000有限元软件,建立了考虑群桩-土动力相互作用的三维有限元模型,分别计算了分离式承台与哑铃型承台两种承台形式下大跨斜拉桥的振动特性与地震响应,探讨了主塔基础承台形式对大跨斜拉桥抗震性能的影响.分析结果表明:主塔基础承台形式的变化对结构纵桥向抗震性能的影响不大,而对结构横桥向抗震性能影响较大;对于本桥而言,主塔基础承台形式采用分离式承台时对主塔结构的抗震性能有利,而采用哑铃型承台时对主塔基础的抗震性能有利,因此,应综合考虑并予以选择承台形式.更多还原

【Abstract】 In combination with a long-span cable-stayed bridge,based on sap2000program,the threedimensional finite element mode which can consider pile-soil dynamic interaction was developed.Vibration characteristics and seismic response of the long-span cable-stayed bridge using separation type pile-cap or dumbbell type pile-cap were analyzed.And effects of main-tower′s pile-cap structure form on seismic performance of the long-span cable-stayed bridge was discussed.The conclusion of the study shows that the change of main-tower′s pile-cap structure form has little influence on the longitudinal seismic response,but has significant influence on the transverse seismic response.For this bridge,when using the separation type pile-cap,the transverse seismic response of the bottom of the pylon will be reduced obviously,but when using the dumbbell type pile-cap,the seismic capacity demand ratio of pile foundation will be improved and so it is of benefit to seismic performance of the bridge foundation.Therefore,it should be taken comprehensive consideration to choose the suitable form of main-tower′s pile-cap structure.更多还原