Abstract Highway bridges are a class of important infrastructure components in transportation networks. Highway bridges will inevitably deteriorate over time due to various external impacts, such as traffic loads and corrosion. In seismic-prone areas, seismic hazard is another critical factor that threatens the normal operation of ageing highway bridges. To ensure adequate safety of ageing highway bridges under potential earthquake shocks, it is imperative to perform proper maintenances during their service life. This paper aims at optimizing the life-cycle maintenance strategies for highway bridges under the combinatorial threats of progressive deterioration and sudden earthquakes. Driven by the distinct characteristics of the two threats, we have proposed a novel hybrid Markov decision process model that integrates a discrete-time Markov decision process model for dealing with progressive deterioration and a continuous-time Markov decision process model for dealing with sudden earthquakes into a unified framework. The proposed model is further reduced into the form of a discrete-time Markov decision process model with an equivalent state transition matrix and an equivalent discount factor, which can be easily solved by dynamic programming. A ternary state space that collectively describes corrosion initiation, corrosion damage cumulation, and seismic damage cumulation is defined. A gamma process and a Poisson process are adopted to model bridge corrosion and earthquake occurrences, respectively. To demonstrate the application of the proposed framework, a numerical example is conducted, in which the optimizations with respect to the maintenance strategy, inspection interval, and design performance level of a hypothetical highway bridge are carried out successively.

中文翻译：

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基于混合马尔可夫决策过程模型的地震灾害公路桥梁全生命周期维护优化策略

摘要 公路桥梁是交通网络中一类重要的基础设施组成部分。由于各种外部影响，例如交通负荷和腐蚀，公路桥梁将不可避免地随着时间的推移而恶化。在地震多发地区，地震灾害是威胁老化公路桥梁正常运行的另一个关键因素。为了确保老化公路桥梁在潜在地震冲击下的足够安全，必须在其使用寿命期间进行适当的维护。本文旨在优化公路桥梁在渐进性退化和突发地震的组合威胁下的全生命周期维护策略。在这两种威胁的不同特征的驱动下，我们提出了一种新颖的混合马尔可夫决策过程模型，它将处理渐进式恶化的离散时间马尔可夫决策过程模型和处理突发地震的连续时间马尔可夫决策过程模型集成到一个统一的框架中。将所提出的模型进一步简化为具有等效状态转移矩阵和等效折扣因子的离散时间马尔可夫决策过程模型，可以通过动态规划轻松求解。定义了共同描述腐蚀开始、腐蚀损伤累积和地震损伤累积的三元状态空间。分别采用伽马过程和泊松过程来模拟桥梁腐蚀和地震发生。为了证明拟议框架的应用，