Structural behaviour and design criteria of under‐deck cable‐stayed bridges subjected to seismic action
Structural behaviour and design criteria of under‐deck cable‐stayed bridges subjected to seismic action
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DOI：
10.1002/eqe.2251
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发表时间：
2013-05
影响因子：
4.5
通讯作者：
A. Camara;A. Ruiz-Teran;P. Stafford
中科院分区：
文献类型：
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作者：
A. Camara;A. Ruiz-Teran;P. Stafford
桥面下斜拉桥是一种非常有效的结构体系，在活荷载作用下，斜拉索的强大贡献允许设计非常细长的桥面，以适应持续和瞬态荷载情况。本文研究了它们在地震激励下的行为，并提出了一套设计准则，涉及轴承的类型和布置、支柱的数量和配置以及斜拉索的横向分布。这些桥梁在受到近场和远场加速度时的非线性行为已经通过使用增量动力分析进行了彻底的研究。提出了一种反映几种振动模式激活时对响应的相关贡献的强度测量方法，并证明该方法对这种结构类型的分析是有效的。当桥梁受到非常强烈的地震激励时，桥下斜拉索系统对减少响应有非常积极的作用。在这种情况下，当使用预应力混凝土桥面时，由于裂缝形成而导致桥面刚度的降低，可以调动缆索系统并提高系统的整体性能。符合欧洲规范8规定的自然加速度也被应用于提出一套在地震易发地区的这种桥梁类型的设计标准。特别注意概述轴承部署的最佳策略。版权所有©2012 John Wiley & Sons， Ltd。
Under‐deck cable‐stayed bridges are very effective structural systems for which the strong contribution of the stay cables under live loading allows for the design of very slender decks for persistent and transient loading scenarios. Their behaviour when subjected to seismic excitation is investigated herein and a set of design criteria are presented that relate to the type and arrangement of bearings, the number and configuration of struts, and the transverse distribution of stay cables. The nonlinear behaviour of these bridges when subject to both near‐field and far‐field accelerograms has been thoroughly investigated through the use of incremental dynamic analyses. An intensity measure that reflects the pertinent contributions to response when several vibration modes are activated was proposed and is shown to be effective for the analysis of this structural type. The under‐deck cable‐stay system contributes in a very positive manner to reducing the response when the bridges are subject to very strong seismic excitation. For such scenarios, the reduction in the stiffness of the deck because of crack formation, when prestressed concrete decks are used, mobilises the cable system and enhances the overall performance of the system. Sets of natural accelerograms that are compliant with the prescriptions of Eurocode 8 were also applied to propose a set of design criteria for this bridge type in areas prone to earthquakes. Particular attention is given to outlining the optimal strategies for the deployment of bearings. Copyright © 2012 John Wiley & Sons, Ltd.