Statistical, risk, and reliability analyses of bridge scour
Statistical, risk, and reliability analyses of bridge scour
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DOI：
10.1061/(asce)gt.1943-5606.0000989
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发表时间：
2014-02
影响因子：
3.9
通讯作者：
J. Briaud;P. Gardoni;Congpu Yao
中科院分区：
文献类型：
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作者：
J. Briaud;P. Gardoni;Congpu Yao
桥梁冲刷是由于水在桥梁支撑物周围流动而造成的土壤流失。冲刷一直是美国桥梁破坏的头号原因，平均每年有22座桥梁因严重变形而倒塌或关闭。本文讨论了与桥梁冲刷有关的三个主题。首先，使用一组数据库来量化与预测和测量的码头冲刷深度之间的散点相关的统计参数，以及确定性预测的码头冲刷深度将超过的概率。这些数据库还用于提供当前预测中的偏差因素。其次，利用这些统计参数建立了基于可靠性的浅、深基础冲刷荷载与阻力系数设计。目标是提供一种设计程序，其中基础的可靠性无论有无冲刷都是相同的。可靠性只涉及成功的概率，因此也就涉及失败的概率。最后，通过使用定义为失败概率乘以结果价值的风险概念，扩大了讨论范围。在第三部分中，与桥梁冲刷相关的风险被量化，并与其他工程结构相关的风险进行了比较。可接受风险的目标值被建议作为结论的一部分。
Bridge scour is the loss of soil by erosion because of water flowing around bridge supports. Scour has been the number one cause of bridge failure in the United States with an average annual rate of 22 bridges collapsing or being closed owing to severe deformation. This paper addresses three topics related to bridge scour. First, a set of databases was used to quantify the statistical parameters associated with the scatter between the predicted and measured pier scour depth, as well as the probability that a deterministically predicted pier scour depth will be exceeded. These databases also were used to provide the bias factors in current predictions. Secondly, these statistical parameters were used to develop a reliability-based load and resistance factor design for shallow and deep foundations subjected to scour. The goal was to provide a design procedure where the reliability of the foundation is the same with or without scour. Reliability only addresses the probability of success and, therefore, of failure. Finally, the discussion was broadened by using the concept of risk defined as the probability of failure times the value of the consequences. In this third part, the risk associated with bridge scour was quantified and compared to risks associated with other engineering structures. Target values of acceptable risk were recommended as part of the conclusions.