Moderated by: Dr. Dante Fratta, U of Wisconsin
Distributed acoustic sensing: on-going research and data visualization
Presented by: Meghan Quinn, P.E. U.S. Army Corps of Engineers
Use of distributed acoustic sensing is increasing in geophysics and civil engineering communities. While rapid improvement in interrogator technology and data processing has accelerated potential applications of the technology, many research basics remain such as day-to-day performance and long-term performance. To study this, two field-testing programs (in different geographic areas) were established in 2019. At both locations, a new portion of fiber optic cable was spliced into an existing array installed ten years earlier. New portions of array were installed in various methods and in various materials in trench sections. A calibrated source was used at set locations to excite the DAS arrays periodically, and surrounding significant weather events. Performance variance and changes over time were documented and will be discussed.
Civil infrastructure monitoring using distributed interferometric measurements
Presented by: Peter Hubbard, UC Berkeley
The development of quantitative distributed acoustic sensing (DAS) has paved the way for extremely sensitive dynamic displacement and strain measurements of civil infrastructure. When coupled to the system of interest, an inert fiber optic cable can be used to measure deformations on the order of the wavelength of laser light being passed through the fiber. In this webinar, two demonstrations of coupled DAS for civil infrastructure monitoring are presented. First, a model wind turbine is monitored for how its dynamic structural behavior changes when flange bolts loosen. Second, a hot-mix asphalt roadway is monitored for its dynamic strain behavior when events occur on the road surface decreasing in size from a pickup truck to a small dog.