Signature frequencies for buried soil anchors

Abstract

Soil anchors with their guy lines are employed in a wide variety of applications. Anchor support for utility poles is the focus of the present study. A nonintrusive measuring system is proposed to monitor the integrity of such guy line ground anchors. The natural longitudinal frequency of the partially buried anchor rod with a terminal buried plate attached can be measured periodically with an accelerometer. An increase in this frequency over time would indicate a possible corrosion-induced loosening of the ground anchor from its buried terminal plate, and the need for anchor replacement. A case study involving an aging and failed utility pole anchor illustrates the need for such frequency monitoring.