Intelligent Infrastructure Systems personnel were called to the Henry Hudson Bridge to provide structural health monitoring services following concerns over the in-service performance of new light fixtures installed on the bridge as part of an overall improvement project.
The concerns expressed by the engineer-of-record included vibration amplification of the light pole and vibration induced stresses at the interface between the light pole and luminaire assembly. The effort by IIS included the design and installation of a temporary structural health monitoring (SHM) system aimed at capturing ambient accelerations and strains due to traffic and wind inputs on the bridge over a 24 hour period.
Intelligent Infrastructure Systems’ staff carried out strict screening procedures to confirm that data captured over the 24 hour period was of high quality and error-free. The data was processed into the natural frequencies and modeshapes of vibration for the light pole and luminaire assembly, strain rainflow histograms of fatigue-prone details, and live load-induced demands on critical locations of the light pole.
The results were summarized into a report detailing the methods and findings of the temporary monitoring study to the engineer-of-record.