Structural health assessment techniques for in-service timber poles

Abstract

Timber utility poles are widely used in power distribution and telecommunication networks. Wood is subjected to deterioration with time, and routine condition assessment works are carried out for in-service timber poles to identify potential defects and their extent for renewal planning. These condition assessment methods need to be reliable and accurate to represent the actual status of poles. Incorrect interpretations regarding the structural integrity of poles may lead to premature pole replacements due to misdiagnosed defects or pole failures due to overlooked defects. The aim of this paper is to provide a state-of-the-art review of various condition assessment techniques for in-service timber poles. The paper reviews the conventional pole inspection methods, semi-destructive techniques and recent developments in non-destructive testing (NDT) techniques. The performance of these techniques is compared and their relative advantages and shortcomings are discussed. Further, the timber deterioration modelling techniques are outlined along with the probabilistic approaches for the condition assessment of timber poles. Finally, potential research gaps that need to be addressed in the future to overcome the issues related to the condition assessment of timber poles are discussed.