Semester of Graduation
Fall 2024
Degree
Master of Civil Engineering (MCE)
Department
Department of Civil and Environmental Engineering
Document Type
Thesis
Abstract
Recent hurricanes (e.g., Hurricanes Laura, Ida, Ian, and Francine) have caused extensive damage to power distribution systems, leaving hundreds of thousands of residents without power. Extreme windstorm-induced power outages have become a key factor affecting community resilience. Structural vulnerability assessments and resilience enhancements of power distribution infrastructure is becoming increasingly important as the electric power grid infrastructure in the United States (and particularly in the Southeastern portion of the U.S.) continues to age. To assess the structural vulnerability, existing references analyzed the failure of the wooden poles mainly considering bending failure caused by wind loads. However, it is worth noting that the wooden poles may suffer from multiple failure mechanisms, including pole bottom fracture and excessive tilting due to foundation softening. Also, the poles may be affected by combined wind and surge/wave loads during major hurricanes. Comprehensive vulnerability analysis of the poles suffering from multiple failure mechanisms under combined wind-surge-wave loads is missing in the existing literature.
To address these limitations, this study focuses on the vulnerability assessment of typical power distribution poles experiencing bottom bending failure and excessive foundation tilting under wind, surge, and wave loading. To analyze the pole’s structural response, the open-source software OpenSees is used to build a 2-D model and run in parallel. A comprehensive finite element model was created considering the elastic deformation of the timber, the taper of the poles, the resistance and deformation of soil, and the P-Delta effects caused by the weight of the pole, transformers, and wires. The fragility curves/surfaces of the poles are computed under two loading conditions: a pure wind case and a wind-surge-wave case where combined wind-wave loads are applied. The vulnerability of the poles is evaluated using the Monte Carlo method. It is found that the depth of the pole’s embedment, and the strength of the soil it is embedded in, has a significant impact on the overall reliability of the pole. Additionally, the vulnerability of timber pole’s is heavily affected by wind- generated waves and storm surge, even in relatively shallow waters.
Date
11-17-2024
Recommended Citation
Taylor, Noah C., "Vulnerability Assessment of Power Distribution Systems Subjected to Winds, Surge, and Waves" (2024). LSU Master's Theses. 6061.
https://repository.lsu.edu/gradschool_theses/6061
Committee Chair
Sun, Chao