Wind Performance of Short Utility Pole Structures

Abstract

Most utility engineers in the United States use the National Electrical Safety Code (NESC) to determine minimum structural loading requirements for the design of transmission and distribution pole structures. The NESC specifies two weather loadings—combined ice and wind loading (rule 250B) and extreme wind loading (rule 250C). However, the current NESC excludes poles with heights above ground of 60 ft or less from the extreme wind loading (rule 250C) design requirement. ASCE 7-98 prescribes extreme wind load requirements for the design of buildings and other structures and contains no extreme wind load exclusion provision for short structures. This paper reviews the adequacy of the current NESC 60 ft exclusion provision for the design of poles located in the 90–140 mph 3 s gust wind speed based on ASCE 7-98.