摘要
为深入了解高墩大跨矮塔斜拉桥主梁的地震响应规律,探讨高墩P-Δ效应与行波效应对主梁地震响应的影响,以某高墩5跨矮塔斜拉桥为例,建立有限元静、动力分析模型,对比分析在地震激励下和活载作用下主梁的动力响应情况,并在此基础上,通过改变墩高,对比分析不同P-Δ效应对主梁地震响应的规律,最后引入行波效应,分析其对主梁地震动响应的影响。结果表明:1)地震作用对大跨高墩桥梁的影响明显大于活载效应;2)当P-Δ效应使结构基本周期变化超过2%,且变化位于地震波位移谱剧烈增长阶段或卓越周期内时,设计中须考虑P-Δ效应的影响;3)行波效应会显著增大主梁的竖向位移和弯矩,且视波速越小影响越大。
To obtain the response law of the main girders of high pier and large span bridges under seismic effects,and to explore the influence law of P-Δ effect and traveling wave effect on the seismic response of the main girders of high piers.In this paper,a high pier five-span extradosed cable-stayed bridge was used as the engineering background,and a finite element static and dynamic analysis model was established to compare and analyze the dynamic response of the main girder under seismic excitation and live load.On this basis,the law of different P-Δ effects on the seismic response of the main beam was compared and analyzed by changing the pier height,and finally,the traveling wave effect was introduced to analyze its effect on the ground vibration response of the main beam.The results show that:1) Tthe impact of earthquake action on long span and high pier bridges is significantly greater than the live load effect;2) When a change in the basic period of the structure exceeds 2% caused by P-Δ effect,and the change is in the stage of rapid growth or predominant period of the seismic wave displacement spectrum,the impact of P-Δ effect must be considered in the design.;3) The traveling wave effect will significantly increase the vertical displacement and bending moment of the main beam,and the smaller the apparent wave velocity,the greater the impact.
作者
柯亮亮
刘亚
苗建宝
冯威
KE Liangliang;LIU Ya;MIAO Jianbao;FENG wei(Xi′an Highway Research Institute Co.,Ltd.,Xi′an 710065;Hunan University,Changsha 410082)
出处
《公路交通技术》
2023年第5期95-103,112,共10页
Technology of Highway and Transport
基金
国家自然科学基金项目(51978257)
陕西省交通科技项目(20-40K,17-19K)。
关键词
桥梁工程
高墩大跨
矮塔斜拉桥
地震动响应
有限元分析
bridge engineering
high pier and long span
extradosed cable-stayed bridge
seismic response
finite element analysis
