Condition based serviceability and reliability assessment of wood pole structures

New procedures have been developed to assess serviceability of existing wood pole structures. Above or below groundline decay is measured using an instrumented drill and mapped using a customised computer program. Pole structures that contain localised mapped decay are analysed using either deterministic or probabilistic finite element approaches to establish a factor of safety regarding strength and/or probability of survival of the structure. If the poles are involved in an uprating/upgrading/life extension project, additional data is obtained to determine the number of survived years, the acceptable level of reliability, and appropriate inspection intervals. The uniqueness and the benefits of the new methodologies are discussed through examples and a case study.