INEEL and University Collaborators Gather for Hurricane Research Conference
Wind and earthquake researchers gathered in Idaho Falls, Idaho, to share recent developments in natural disaster hazards mitigation research. Members of the Partnership for Natural Disaster Reduction (PNDR) met March 23 to discuss their PNDR-funded research.
The PNDR is a program created at the Department of Energy's Idaho National Engineering and Environmental Laboratory to better understand the forces behind natural disasters and to systematically design affordable housing that can withstand them. Plans for a large-scale extreme wind research facility are included in the PNDR HomeSaver project. PNDR funds come from public sources such as the DOE and private sources such as the manufactured housing industry.
Planned months ago, the second annual PNDR Collaborators Meeting brought together civil and mechanical engineers, computer scientists, architects and hurricane chasers for a day-long conference. The researchers hailed from local regions such as Washington and Wyoming and as far away as Texas, Mississippi, Georgia, South Carolina, and Florida. Three insurance companies also sent representatives to the meeting.
Hurricanes, tornadoes and storm surges cause billions of dollars in damage and claim hundreds of lives annually in the U.S. However, only several million dollars are spent annually to research ways to reduce or prevent that damage. The PNDR program recognizes the need for a concerted, nationwide research effort in natural disaster hazards mitigation.
The program not only funds such research but also brings together distinct groups of scientists and engineers who wouldn't normally meet. The researchers discuss and collaborate on projects aimed at understanding extreme weather and the response of structures such as housing and highways to hurricanes, tornadoes and earthquakes. The program plans to use the information to better design housing in an affordable manner.
Natural disaster hazards mitigation spans a wide gamut of research efforts. Among about a dozen projects presented at the meeting were studies on the response of a full-scale manufactured house to static pressures, meant to simulate a heavy wind load; measuring the sound put out by stressed structural joints to nondestructively to measure any internal damage; attempts to study the effectiveness of shutters on houses faced with extreme weather; and the development of laser-based sensors that determine the 3-dimensional structure of wind.
To capture data on the wind structure of violent storms, teams of researchers from INEEL, Clemson University in South Carolina, and Texas Tech University followed hurricanes around last summer. Armed with 30-foot-tall towers laden with meteorological instrumentation, the teams positioned themselves in the middle of the storms to collect data. While engineers from the universities and INEEL reported on data they collected, INEEL engineer Tom Larson described some of Hurricane Georges' damage he witnessed.
"We all had hardhats on," Larson said, as he pointed out precautions to take while chasing hurricanes. Showing a slide of a crumpled metal shed, he said, "Parts of it looked like a piece of licorice that had been twisted up."
INEEL engineer Jim O'Brien presented some of the first data generated at the 1/14 Scale Windstorm Center, the hurricane wind-simulator built at the INEEL as a model for the large-scale windstorm center. A manufacturer of dome homes donated a Barbie doll-sized, 1/12-scale fiberglass model of a one-story dwelling. Constructed as hemispheres, these homes have been known to be left standing as hurricanes devastated traditional housing around them.
O'Brien took advantage of the Scale Windstorm Center's "32-channel high speed electronic pressure scanning system" to measure the air pressure created by wind around the 1/12-scale dome home. The system consists of 32 tubes attached to holes on the model, which transmit pressure to electronic sensors. Overlaying this information on a computer image of the home revealed the areas on the dome that were subjected to more or less air pressure.
Overall, the researchers learned the biggest risk for damage is if the home is improperly secured to the earth. Referring to the computerized image, O'Brien said, "You can see the large negative pressure near the top, so the dome actually wants to lift off the ground. And we verified that experimentally."
In another study, civil engineer Chris Pantelides and colleagues at the University of Utah reinforced with carbon fibers a concrete highway bridge built in the 1960s. They wrapped the fibers -- a composite of carbon fibers and epoxy -- around the joints and the columns of a section of Interstate-15 overpass in Utah that was about to be demolished. Then they pushed on the bridge to see how much force and movement the joints and columns could withstand. They also tested an already damaged joint in the same way.
According to Pantelides, the healthy highway bridge wrapped with the composite fibers could handle twice as much movement as an unwrapped joint. On the damaged joint, they were able to recover 90% of its original movement and strength by wrapping it. Pantelides said they are planning on reinforcing the joints on Interstate-80 in Utah as part of an infrastructure upgrade in preparation for the 2002 Olympics.
PNDR program manager Cheryl O'Brien reported that customers are expressing interest for both the 1/14 scale windstorm center and the full-scale facility, including steel-roofing companies and one housing manufacturer that is ready to ship a 26-foot-by-32-foot structure to the INEEL as soon as a large enough facility is built for testing.
Addressing the recent National Research Council review committee's recommendation to not build the full-scale research facility at this time, PNDR program director Barry Short emphasized the importance of wind research and that a facility could be constructed with enough flexibility to accommodate future research findings. Noting that the committee's recommendation for construction was "Not yet" instead of "Not at all," he agreed more wind data will be useful in operation of the facility. Both data collection and construction take time, though, and hurricanes won't wait. "We're an engineering lab. We know it'll take three years to build a large-scale facility. Do we want to do it in parallel [with research] or in series?"
And pointing out that with or without the large-scale facility under construction, the research that PNDR promotes is important, Short said, "We're going to continue with our research agenda and will continue to build collaborations with other national stakeholders."
INEEL celebrates its 50 year anniversary in 1999. The national laboratory is operated for the U.S. Department of Energy by Lockheed Martin Idaho Technologies Company.
Note to Editors: More information on the PNDR program, which includes an artist's rendering of the full-size windstorm facility, can be found at http://www.inel.gov/homesaver/index.html.