王草, 李全旺. 考虑非平稳车载过程的在役桥梁时变可靠度分析[J]. 工程力学, 2016, 33(3): 18-23. DOI: 10.6052/j.issn.1000-4750.2014.05.0451
引用本文: 王草, 李全旺. 考虑非平稳车载过程的在役桥梁时变可靠度分析[J]. 工程力学, 2016, 33(3): 18-23. DOI: 10.6052/j.issn.1000-4750.2014.05.0451
WANG Cao, LI Quan-wang. TIME-DEPENDENT RELIABILITY OF EXISTING BRIDGES CONSIDERING NON-STATIONARY LOAD PROCESS[J]. Engineering Mechanics, 2016, 33(3): 18-23. DOI: 10.6052/j.issn.1000-4750.2014.05.0451
Citation: WANG Cao, LI Quan-wang. TIME-DEPENDENT RELIABILITY OF EXISTING BRIDGES CONSIDERING NON-STATIONARY LOAD PROCESS[J]. Engineering Mechanics, 2016, 33(3): 18-23. DOI: 10.6052/j.issn.1000-4750.2014.05.0451

考虑非平稳车载过程的在役桥梁时变可靠度分析

TIME-DEPENDENT RELIABILITY OF EXISTING BRIDGES CONSIDERING NON-STATIONARY LOAD PROCESS

  • 摘要: 近年来,我国有大批桥梁得以新建。与此同时,日益增加的车辆荷载使得在役桥梁面临着更大的服役风险。在已有研究中,桥梁结构的可靠度评估将车载随机过程看作平稳泊松过程,且假定荷载效应概率模型在评估期内独立同分布。历史数据表明,我国的汽车荷载存在明显的逐年增加的趋势,随时间不再服从同一分布,已有方法也不再适用。为此,该文改进了已有方法,提出了考虑非平稳车载过程的在役桥梁时变可靠度评估新方法。算例表明,改进的方法简便易行,结果准确。已有方法可看作是该文改进方法的特例。随后,利用这一方法研究了结构可靠度对车载随机过程参数的敏感性。结果表明,车载随机过程参数对结构可靠度的影响显著。在20年的评估期内,均值每年增加1.1%或标准差每年增加1.3%,都会造成结构的失效概率增大两倍。

     

    Abstract: A large number of new bridges have been built in China during the past decades, and now many of them are suffering greater risk of serviceability from ever-increasing traffic loads. In previous studies, when evaluating structural reliability for existing bridges, the loading process is assumed as a stationary Poisson process and all loads follow the same distribution. However, significant tendency of increasing is observed from recorded traffic data of our country in the past years, thus the existing methodology is not valid when load change occurs. In this paper, an improved method is proposed to calculate the time-dependent reliability with non-stationary load process. Illustrative examples demonstrate the accuracy and effectiveness of the proposed method. The existing method is a special case of the proposed one. By means of the proposed method, the sensitivity of structural reliability is investigated to the parameters of stochastic traffic load process. It is shown that the traffic load change has great impact on structural reliability; the increment of mean load by 1.1% per year, or the increment of standard deviation of load by 1.3% per year results in a twice failure probability in a service period of 20 years.

     

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