Lifeline infrastructure systems such as a power transmission network in coastal regions are vulnerable to strong winds generated during tropical cyclones. Understanding the fragility of individual towers is helpful in improving the resilience of such systems. Fragility curves have been developed in the past for some regions, but without considering relevant epistemic uncertainties. Further, risk and resilience studies are best performed using the fragility curves specific to a region. Such studies become particularly important if the region is exposed to cyclones rather frequently. This paper presents the development of fragility curves for high-voltage power transmission towers in the state of Odisha, India, based on macro-level damage data from 2019 cyclone Fani, which was obtained through concerned government offices. Two types of damages were identified, namely, collapse and partial damage. Accordingly, fragility curves for collapse and functionality disruption damage states were developed considering relevant aleatory and epistemic uncertainties. The latter class of uncertainties included that associated with wind speed estimation at a location and the finite sample uncertainty. The most significant contribution in the epistemic uncertainty was due to the wind speed estimation at a location. The median and logarithmic standard deviation for the 50th percentile fragility curve associated with collapse was close to that for the functionality disruption damage state. These curves also compared reasonably well with those reported for similar structures in other parts of the world.
翻译:了解个别塔塔的脆弱性有助于提高这些系统的抗御能力。过去曾为某些区域开发过易变曲线,但没有考虑到相关的隐性不确定性。此外,风险和复原力研究最好使用一个区域特有的脆弱曲线进行。如果该区域经常遭受气旋,这种研究就变得特别重要。本文件介绍了印度奥迪沙州高压电源传输塔的脆弱曲线的发展,其依据是通过有关政府部门获得的2019年飓风法尼的宏观级损害数据。确定了两种类型的损害,即崩溃和部分损害。因此,为崩溃和功能破坏破坏而开发的脆弱曲线是考虑到一个区域特有的脆弱性曲线和感性不确定性。后一类的不确定性包括与某一地点的风速估计和有限的抽样不确定性有关。印度奥迪沙州高压电能传输塔的脆弱曲线的形成,其最显著的贡献是某个地点的风速估计。所报告的50 % 与50 %其他州性结构的中位和对等标准曲线的破坏程度,这些与50 %的临界值的临界值和对50 %的临界值。