【摘要】 本文以一座试设计的主跨1 400 m斜拉桥为例,采用弹塑性分析方法并以Park损伤指数作为评价指标,研究了斜拉桥典型结构体系顺桥向和横桥向的地震损伤与破坏模式;在此基础上,进一步研究了不同频率成分地震动对其地震损伤与破坏模式的影响。结果表明:地震作用下主塔和桥墩属于易损构件,需重点关注;主塔顺桥向、桥墩顺桥向和横桥向发生典型的单塑性铰破坏模式,而主塔横桥向则发生双塑性铰破坏模式;主塔和桥墩的地震损伤受输入地震频率成分的影响非常显著,且低频成分越丰富,其地震损伤越严重,但不会改变其破坏模式。更多还原

【Abstract】 Elasto-plastic analyses were carried out to investigate seismic damage and failure patterns by employing Park damage indices for a trial designed cable-stayed bridge,which has a central span of 1400 m and is excited by ground motions with various intensities. In addition,the influences of earthquake input including different frequency components on structural seismic damage and failure patterns were further investigated. The results show that the pylon and piers are subjected to damage under earthquake input; the top and bottom regions of the pylon are simultaneously subjected to severe damage under extreme earthquake input,indicating that the pylon experiences an unexpected failure patterns with double plastic hinges,whereas the piers experience a typical flexural failure pattern,with only one plastic hinge concentrated at the bottom region to the pier in the transverse direction; the piers and pylon experience a typical flexural failure pattern,with only one plastic hinge concentrated at the bottom region of them in the longitudinal direction; the influences of earthquake input including different frequency components on the seismic damage to the cable-stayed bridge are very noticeable,and the structure suffers from more severe damage when earthquake input includes more lower frequency components. However,different earthquake inputs cannot change the failure patterns of the cable-stayed bridge.更多还原