Abstract Structural deterioration poses a substantial threat to the safety, serviceability, and functionality of bridges. Since bridges are connected in transportation networks, their failure can dramatically alter traffic flow, causing immense social consequences such as large-scale traffic delay and additional vehicle operating cost. In this paper, a novel method is proposed for life-cycle management of deteriorating bridge networks. The proposed method aims at minimizing network-level risks associated with deterioration-induced bridge failure. To combat the deficiencies of existing Monte Carlo simulation-based risk assessment methods, the proposed method adopts a non-simulation approach that relies on risk bounds of deteriorating bridge networks. In particular, this method uses system reliability analysis to determine the occurrence probabilities of various bridge failure scenarios in a network. For each failure scenario considered, traffic assignment is conducted to predict the traffic flow in the damaged network and the network-level consequences. The upper and lower bounds of the network-level risk are then formulated, allowing for efficient and accurate risk assessment with only a few traffic assignment operations. Estimated by the average value of its upper and lower bounds, the network-level risk is used as the optimization objective in a metaheuristic search procedure to obtain optimal life-cycle maintenance plans including the maintenance schedule and the investment on each maintenance action. The proposed method excels in its ability to account for the impacts of unlikely, yet high-impact events, as well as its ability to obtain optimal or near-optimal life-cycle maintenance plans that can more effectively reduce risks than those obtained using simulation-based methods.

中文翻译：

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具有网络级风险界限和系统可靠性分析的恶化桥梁网络的生命周期管理

摘要 结构退化对桥梁的安全性、适用性和功能性构成了重大威胁。由于桥梁连接在交通网络中，它们的故障会极大地改变交通流量，造成巨大的社会后果，如大规模交通延误和额外的车辆运营成本。在本文中，提出了一种新的方法来对不断恶化的桥梁网络进行生命周期管理。所提出的方法旨在最小化与恶化引起的桥梁故障相关的网络级风险。为了克服现有的基于蒙特卡罗模拟的风险评估方法的不足，所提出的方法采用了一种依赖于不断恶化的桥梁网络的风险界限的非模拟方法。特别是，该方法使用系统可靠性分析来确定网络中各种桥梁故障场景的发生概率。对于考虑的每个故障场景，进行流量分配以预测损坏网络中的流量和网络级后果。然后制定网络级风险的上限和下限，只需少量流量分配操作即可进行有效和准确的风险评估。通过其上下限的平均值估计，网络级风险作为元启发式搜索过程中的优化目标，以获得最佳的全生命周期维护计划，包括维护计划和每个维护行动的投资。所提出的方法在考虑不太可能的影响的能力方面表现出色，