Self-supported Wood Pole Fixity at ANSI Groundline

Most utility engineers in the United States use the American National Standard for Wood Poles, American National Standards Institute (ANSI) 05.1, to determine the dimensional properties of different species of wood poles. ANSI 05.1 defines a groundline distance from the butt for each pole height for use when a definition of groundline is necessary in order to apply requirements relating to scars, straightness, and likewise. In addition, the groundline distance is used to determine the horizontal load capacity of each class of pole. This paper reviews the adequacy/fixity for different pole heights and species with setting depths based on the ANSI 05.1 groundline location in soils with different properties. The effects on the pole setting depths of backfill diameter and strength as well as groundline forces are also discussed.