Reliability-Based Inspection Protocols for Mast-Arm Sign Support Structures

Abstract

There have been numerous examples of poor in-service performance of welded, tube-to-transverse plate connections within mast-arm sign support structures in the last several decades. A considerable amount of research has been devoted to identifying structural response characteristics of these sign support systems and identifying how these connections may be repaired, retrofitted, or designed to facilitate longer service lives. Little attention has been given to using a systematic reliability-based approach to assess the probability of fatigue-induced crack initiation for in-service structures. The present research effort focuses on quantifying sources of uncertainty and formulating a reliability-based approach for prescribing inspection intervals corresponding to user-specified levels of probability of fatigue-induced crack initiation. The results indicate that implementation of reliability-based assessment procedures can be used to assign inspection intervals based on this probability, and the engineering community can use the results to establish inspection intervals that better align inspection needs with limited fiscal and human resources.