|
Journal of Zhejiang University SCIENCE A
ISSN 1673-565X(Print), 1862-1775(Online), Monthly
2014 Vol.15 No.5 P.351-363
Seismic response study on a multi-span cable-stayed bridge scale model under multi-support excitations. Part I: shaking table tests
Abstract: With the rapid development of bridge engineering in China, multi-span cable-stayed bridges have become one of the main structures of modern highways and railways for crossing rivers or straits. In this study, a 1:100 scale model of a three-tower cable-stayed bridge was tested using a shaking table array system. The mechanism associated with the seismic response of the scale model under uniform and non-uniform excitations was clarified. The results from the tests indicated that: (1) the strong vibration responses of the main girder and towers under four different horizontal earthquake wave excitations were identified, and the seismic responses of the scale model were most evident under uniform Jiangxin (JX) wave excitation; (2) the seismic performances of the main girder and towers of the scale model were adversely affected by traveling wave effects, especially when the wave velocity exceeded 616 m/s, which suggests that traveling wave effects should be considered in the seismic design of multi-tower cable-stayed bridges; (3) when the peak acceleration value of the El Centro (EC) wave reached 4.0 m/s2, shear failure of the bearing of the middle tower first appeared. This kind of shaking table tests will help to improve our understanding of dynamic performance, and will be especially useful in the design process and numerical simulation of multi-span cable-stayed bridges with large span subjected to spatially varying earthquake ground motions.
Key words: Multi-span cable-stayed bridge, Earthquake shaking table tests, Uniform excitations, Non-uniform excitations, Traveling wave effect, Shear failure of bearing
创新要点:1.建立了地震模拟振动台多台阵试验方法,并首次将其应用于多塔斜拉桥全桥比例缩尺模型的地震响应分析之中;2.通过地震模拟振动台试验,揭示了多塔斜拉桥在多点一致激励和多点非一致激励的地震响应特性并提出了多塔斜拉桥在强震下的破坏模式。
研究方法:1.基于动力相似理论,设计与制作了多塔斜拉桥的全桥比例缩尺模型(图2);2.利用地震模拟振动台多台阵试验,根据在不同地震波作用下和考虑行波效应后多塔斜拉桥模型的主梁和主塔响应,分析了多塔斜拉桥在多点一致激励和多点非一致激励的地震响应特性
(图5~图8);3.根据在地震波不同强度作用下多塔斜拉桥模型的主梁和主塔响应,分析了多塔斜拉桥在强震下的破坏模式和地震响应(图9)。
重要结论:1.江心波作用下该多塔斜拉桥的地震响应大于其他三种地震波;2.多塔斜拉桥在抗震设计时需要考虑行波效应的影响;3.在El-Centro波的加速度峰值高达4.0 m/s2时,多塔斜拉桥模型出现了支座破坏。
关键词组:
References:
Open peer comments: Debate/Discuss/Question/Opinion
<1>
DOI:
10.1631/jzus.A1300339
CLC number:
U448.27
Download Full Text:
Downloaded:
4462
Download summary:
<Click Here>Downloaded:
2829Clicked:
12293
Cited:
0
On-line Access:
2024-08-27
Received:
2023-10-17
Revision Accepted:
2024-05-08
Crosschecked:
2014-04-22