DesignSafe Radio Natural Hazards Engineering Research Infrastructure

In our final episode with FIU meteorologist Erik Salna, we learn about the Wall of Wind Challenge, an annual event for high school students. NHERI researchers provide a specific wind mitigation challenge. Student teams design and build a protective structure, and then get the chance to test their designs in the Wall of Wind. It’s an exciting competition, which is judged by engineers who are Wall of Wind alums! See below for links to the 2024 event and Salna’s template for conducting this popular STEM competition for high schools.

FIU-based meteorologist and educator Erik Salna relates some unusual but important WOW experiments to test the effects of wind loading on civil infrastructure such as construction cranes and electrical power towers. One unique project used flying debris in the wind tunnel to derive an algorithm for determining wind speeds in video captures.

Meteorologist and educator Erik Salna provides nitty-gritty details on the gigantic, NSF-funded wind research lab called the Wall of Wind, or WOW. Located at Florida International University in Miami, the WOW facility is part of the NSF-funded NHERI network. Each of WOW’s 12-fans are six feet in diameter and weigh nearly 15,000 pounds. Powered up together, the 720HP electric motors can reproduce category 5 hurricane wind speeds, 157MPH.

UC Davis professor Alejandro Martínez is moving his bio-inspired snakeskin piles into industry practice. The novel pile-surface employs “frictional directionality” characteristic of snakeskin. Field trials provided better than expected results, and Martínez is now working to get his new design into the hands of practicing geotechnical engineers. Much of his NSF-supported research took place at the NHERI at UC Davis Center for Geotechnical Modeling; the project is part of the NSF-funded Engineering Research Center, the Center for Bio-mediated and Bio-inspired Geotechnics, CBBG, at Arizona State University.

UC Davis professor Alejandro Martínez explains how biogeotechnical engineers leverage solutions from lifeforms like worms, trees, and bacteria. It starts with fundamental, cross-disciplinary work with biologists. Then, at the UC Davis Center for Geotechnical Modeling (CGM), centrifuge tests fill an important gap between laboratory ideas and full-scale field tests. For instance, by replicating ground stress and increased gravity in a centrifuge, geotechs can model and test designs at greater soil depths and across soil types. The NHERI CGM facility functions as a testbed for the NSF-funded Engineering Research Center (ERC) called the Center for Bio-mediated and Bio-inspired Geotechnics, CBBG, based at Arizona State University.

Geotechnical engineer Alejandro Martínez joins us to discuss a new and multidisciplinary engineering subfield called biogeotechnics. “Bioinspired” research examines and mimics ways that plants, animals and bacteria successfully interact with soil. For example: how tree roots successfully resist wind loads. “Biomediated” research uses biological elements to improve soil. For example, byproducts of certain bacteria can cement and desaturate soil — potentially preventing liquefaction in susceptible areas.