Utility poles would collapse by their structural instability as well as time-dependent material deterioration. Particularly, the moment carrying capacity of leaning poles would be dramatically reduced during extreme wind events. In this paper, we regard leaning poles as warning signs of potential failures that can affect the power distribution network performance and estimate the failure probability of leaning poles. To analyze the moment behavior of leaning poles, we propose a new probabilistic framework for computing three types of loads by wind pressure, overturning force, and conductor tension. A set of fragility curves of utility poles with given ages and leaning angles are presented to assess the impact of leaning on the probability of failure. The proposed analytics are tested through a case study on the parts of the power distribution network in Houston, TX. By examining the progress of failure in the network, this method enables to analyze potentially vulnerable utility poles that are likely to threaten the power distribution system reliability under varying wind speed. Thus, this research has the potential to support risk-informed decision-making for power distribution infrastructure systems and ultimately enhance the urban community resilience to blackouts caused by the power distribution system disruption in extreme weather.

电线杆会因其结构不稳定性以及随时间变化的材料劣化而倒塌。特别地，在极端风事件期间，倾斜杆的力矩承载能力将大大降低。在本文中，我们将倾斜杆视为可能影响配电网络性能的潜在故障的警告信号，并估计倾斜杆的故障概率。为了分析斜杆的力矩特性，我们提出了一个新的概率框架，用于计算风压，倾覆力和导体张力三种类型的载荷。给出了一组给定使用年限和倾斜角度的电线杆的脆性曲线，以评估倾斜对失效概率的影响。通过对德克萨斯州休斯顿的配电网络各部分进行案例研究，对提出的分析进行了测试。通过检查网络故障的进展，该方法可以分析潜在的易受攻击的电线杆，这些电线杆可能会在风速变化时威胁配电系统的可靠性。因此，这项研究有可能支持配电基础设施系统的风险决策，并最终增强城市社区对极端天气下配电系统中断所造成的停电的抵御能力。