Long-span spatial structures are susceptible to cumulative fatigue damage over their lifespan due to prolonged exposure to wind loads. The degradation in material properties resulting from fatigue can impact the structure's performance to resist earthquakes. However, previous studies and current design specifications do not address the issue of wind-induced fatigue in long-span spatial structures, making it difficult to evaluate the multihazard risk of the facilities under the combined action of fatigue and earthquakes. In this study, an assessment framework for the lifetime multihazard fragility of long-span spatial structures subjected to fatigue and earthquakes is developed to address this issue. The innovation of the proposed wind-induced fatigue analysis is that the influence of wind direction can be considered. Multihazard fragility surfaces are established with a mixed exponential model to assess the seismic fragility of the structure with different service times. The proposed method is applied to the seismic analysis of a typical single-layer Kiewitt-8 reticulated dome (SK8RD) to verify its feasibility. The results demonstrate that after 47 years of service, the ultimate bearing capacity of SK8RD decreases by 45.5% due to the wind-induced fatigue, while its collapse probability increases by 25.3% under the seismic action. Neglecting wind direction randomness and focusing solely on a single direction can lead to an overestimation of wind fatigue damage by more than twofold. Utilizing the probabilistic multihazard demand model based on the mixed exponential function enhances the regression accuracy by 12.9%, facilitating a more precise assessment of multihazard fragility for the SK8RD subjected to seismic and long-term wind fatigue. The proposed framework offers a valuable tool for evaluating multihazard risk considering the wind-induced fatigue for in-service long-span spatial structures.

中文翻译：

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考虑风致疲劳效应的大跨空间结构寿命地震易损性分析

由于长期暴露在风荷载下，大跨度空间结构在其使用寿命期间很容易受到累积疲劳损坏。疲劳导致的材料性能下降会影响结构的抗震性能。然而，以往的研究和现行的设计规范并未解决大跨度空间结构的风致疲劳问题，导致难以评估疲劳和地震联合作用下设施的多灾风险。在本研究中，开发了一个针对疲劳和地震作用下大跨度空间结构的生命周期多灾害脆弱性的评估框架来解决这个问题。所提出的风致疲劳分析的创新之处在于可以考虑风向的影响。采用混合指数模型建立多灾种易损性面，评估不同使用时间结构的地震易损性。将所提方法应用于典型单层Kiewitt-8网状穹顶（SK8RD）的抗震分析，验证了其可行性。结果表明，使用47年后，SK8RD的极限承载力因风致疲劳降低了45.5%，而在地震作用下倒塌概率增加了25.3%。忽视风向随机性并仅关注单个方向可能会导致风疲劳损伤高估两倍以上。利用基于混合指数函数的概率多灾种需求模型，回归精度提高了12.9%，有利于更精确地评​​估SK8RD在地震和长期风疲劳作用下的多灾种脆弱性。所提出的框架为评估多灾种风险提供了一个有价值的工具，考虑到在役大跨度空间结构的风致疲劳。