Abstract The scope of this paper is to evaluate different approaches for the prediction of the probability of failure of uncertain railway bridges subjected to high-speed trains. The peak acceleration of a bridge, which is commonly the governing response quantity for dynamic bridge design and failure, depends strongly on the type of train and the train speed. Since in many cases the critical speeds related to response maximums are below the design speed and failure, and during operation the speed varies up to the design speed, the assessment of the probability of failure is not straightforward. In this contribution, several more sophisticated measures of the probability of failure of the bridge-train interaction problem are proposed, considering the peak acceleration as a function of the speed in a certain interval and the distribution of the actual train speed. These measures are tested on two random test bridges, taking into account the main sources of uncertainty, i.e. damping, track irregularities, and the environmental impact. The mechanical model used for the prediction of the dynamic bridge response is composed of a beam bridge crossed by a planar mass–spring damper model of the train. In this simplest approach that considers explicitly dynamic bridge-train interaction, random irregularity profiles capture the effect of track irregularities. It is shown that in certain speed intervals the predicted probability of failure strongly depends on the underlying measure of the probability of failure. In the first example bridge, whose response is governed by a pronounced resonance peak, exceedance of the serviceability limit state is predicted by all measures at virtually the same speed. The second example problem, where track irregularities lead to considerable response amplifications, only some of the measures predict failure. The results of this study may serve as an impulse for a more in-depth discussion on the appropriate prediction of the probability of failure of bridge-train interaction.

中文翻译：

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高速列车桥梁失效概率预测方法

摘要 本文的范围是评估预测高速列车下不确定铁路桥梁失效概率的不同方法。桥梁的峰值加速度通常是动态桥梁设计和破坏的控制响应量，在很大程度上取决于列车类型和列车速度。由于在许多情况下与响应最大值相关的临界速度低于设计速度和故障，并且在运行期间速度随设计速度变化，因此对故障概率的评估并不简单。在这个贡献中，提出了几种更复杂的桥梁-列车相互作用问题的失效概率度量，考虑峰值加速度作为一定区间内速度和实际列车速度分布的函数。这些措施在两个随机测试桥上进行测试，考虑到不确定性的主要来源，即阻尼、轨道不规则和环境影响。用于预测动态桥梁响应的力学模型由横过梁桥的列车平面质量-弹簧阻尼器模型组成。在这种考虑明确动态桥梁-列车相互作用的最简单方法中，随机不规则剖面捕捉轨道不规则的影响。结果表明，在某些速度区间内，预测的故障概率很大程度上取决于故障概率的基本度量。在第一个示例桥中，其响应由明显的共振峰控制，所有措施都以几乎相同的速度预测超过使用极限状态。第二个示例问题，其中轨道不规则导致相当大的响应放大，只有一些措施可以预测失败。这项研究的结果可能会推动更深入地讨论桥梁与列车相互作用的失效概率的适当预测。