Performance Evaluation of Light Pole Structures Through SHM

Lighting pole structures are susceptible to structural damage due to environmental factors such as wind-induced vibrations, particularly as they approach or exceed their design life. Current ASCE/SEI 72 standard practices recommend periodic visual inspections including nondestructive evaluation of welds inspections. Though commonly accepted, this approach can be a time-intensive and expensive inspection solution to asset management. The focus of this chapter is the performance evaluation of a large portfolio of light poles with structural health concerns. The light poles experienced multiple recorded incidents of excessive vibrations which were visually characterized as being the effect of vortex shedding in higher-order modes. The frequent occurrence of the observed events prompted the deployment of potentially unnecessary remediations. Prior to moving forward with the installation of damping systems on each pole, a data-driven, structural health monitoring (SHM) approach to intelligent asset management was investigated as a potential alternative solution for other portfolios. Five pairs of light poles, each pair with the same loading and geometry, were selected for the study. Each pair of light poles was outfitted with SHM equipment to continuously measure vibration responses to wind loading over 6 months. Only one light pole from each pair had dampers installed to adequately compare the performance of the original and remediated light pole configurations. Accounting for specified project constraints, the SHM system chosen was a single package, ruggedized sensor that was easy to install in a way that did not damage or physically alter the existing pole. This chapter presents the SHM program and the primary elements of the data analysis approach implemented to evaluate the pole performance. The chapter demonstrates that SHM is a viable alternative to traditional asset management.