华南理工大学学报(自然科学版) ›› 2025, Vol. 53 ›› Issue (4): 13-21.doi: 10.12141/j.issn.1000-565X.240076

• 土木建筑工程 • 上一篇    下一篇

基于随机场的大跨悬索桥挠度可靠度评估方法

程进1,2, 孙克荻1, 袁义1   

  1. 1.同济大学 土木工程学院,上海 200092
    2.同济大学 土木工程防灾减灾全国重点实验室,上海 200092
  • 收稿日期:2024-02-08 出版日期:2025-04-25 发布日期:2024-11-08
  • 通信作者: 孙克荻(2000 —),男,硕士生,主要从事大跨桥梁研究。 E-mail:13521523833@163.com
  • 作者简介:程进(1971—),男,博士,研究员,主要从事大跨桥梁研究。E-mail: chengjin@tongji.edu.cn
  • 基金资助:
    国家重点研发计划项目(2021YFB1600300)

Deflection Reliability Assessment Method of Long-Span Suspension Bridge Based on Random Field

CHENG Jin1,2, SUN Kedi1, YUAN Yi1   

  1. 1.College of Civil Engineering,Tongji University,Shanghai 200092,China
    2.State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China
  • Received:2024-02-08 Online:2025-04-25 Published:2024-11-08
  • Contact: 孙克荻(2000 —),男,硕士生,主要从事大跨桥梁研究。 E-mail:13521523833@163.com
  • About author:程进(1971—),男,博士,研究员,主要从事大跨桥梁研究。E-mail: chengjin@tongji.edu.cn
  • Supported by:
    the National Key R & D Program of China(2021YFB1600300)

摘要:

大跨度悬索桥造价高,通行量大,扮演着交通网络的关键角色。作为控制性工程,目前主要采用有限元方法等确定性的分析方法对其安全可靠性进行计算和分析。但是实际工程中的结构参数具有不确定性,同时在空间上还存在变异性和相关性,故引入随机场因素的影响。采用数值分析方法,结合随机场理论与可靠度理论,提出了基于随机场的大跨度悬索桥可靠度评估方法。方法主要包括3方面内容:采用中心点法和相关函数处理随机场;采用有限元方法进行结构数值分析;采用一次二阶矩法中的验算点法进行结构可靠度指标计算。介绍了方法的具体实现流程,编写了与之对应的分析程序,通过若干数值算例验证了方法和程序的准确性和适用性。最后以三塔四跨悬索桥——温州瓯江北口大桥为工程实例,考虑桥梁结构参数的不确定性及其在空间上的变异性和相关性,在正常使用极限状态下对其挠度可靠度进行评价,分析了考虑随机场对温州瓯江北口大桥挠度可靠度指标的影响。结果表明:该文提出的方法适用于大跨度悬索桥的可靠度评估。考虑随机场相比不考虑随机场计算得到的正常使用极限状态下的挠度可靠度指标偏小。这说明,忽略大跨度悬索桥结构参数在空间上的变异性和相关性,会导致过高估计结构在正常使用极限状态下的挠度可靠度。

关键词: 悬索桥, 随机场, 一次二阶矩法, 有限元分析, 可靠度指标

Abstract:

Long-span suspension bridges are costly to construct but play a crucial role in transportation networks due to their ability to handle high traffic volumes. As a control engineering project, the safety and reliability of long-span suspension bridges are primarily assessed using deterministic analysis methods, such as the finite element method, for calculation and analysis. However, in practical engineering, structural parameters exhibit uncertainty and simultaneously variability and correlation exist in spatial distribution. Hence, the influence of random field factors was incorporated. By adopting numerical analysis methods and integrating random field theory with reliability theory, a reliability assessment method for long-span suspension bridges based on random fields was proposed. This method primarily consists of three components: the use of the center-point method and correlation functions to handle random fields; the application of the finite element method for structural numerical analysis; and the use of the first-order second-moment method, specifically the design point method, to calculate structural reliability index. The specific implementation process of the method was introduced, and corresponding analysis programs were deve-loped. Several numerical examples were used to verify the accuracy and applicability of the method and the program. Finally, taking the three-tower four-span suspension bridge, the Wenzhou Oujiang North Bridge, as an engineering case, the reliability of its deflection under normal operating limit states was assessed considering the uncertainty of structural parameters as well as their spatial variability and correlation. The impact of random fields on the deflection reliability index of the Wenzhou Oujiang North Bridge was analyzed. Results indicate that the proposed method is suitable for the reliability assessment of long-span suspension bridges. When considering the random field, the deflection reliability index under the normal use limit state is found to be smaller compared to the calculation that ignores the random field. This indicates that neglecting the spatial variability and correlation of the structural parameters in a long-span suspension bridge leads to an overestimation of the deflection reliability under normal use limit state.

Key words: suspension bridges, random fields, first-order second-moment method, finite element analysis, reliability index

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