One of the research team's surprising conclusions: when it comes to the damage they wreak, hurricanes and tsunamis can bring surprisingly similar forces to bear.
"A lot of the hurricane damage along the Mississippi coastline came from storm surges -- not from high winds or levee flooding that occurred in the New Orleans area," said Yin Lu "Julie" Young, an assistant professor of civil and environmental engineering at Princeton University. "Storm surges result in very different mechanisms. When it comes to forces on a structure, what happens in a storm surge is very similar to what happens in a tsunami."
During a storm surge, structures that were built to withstand the downward force of gravity now must cope with a totally different force: the upward and lateral push of water. In addition, buildings have to withstand assaults from debris caught up in the surge.
"Eighteen-wheeler containers, freed floating barges, and boats can all become projectiles that will strike objects in their path," said Young. "Large debris may also become lodged between structural elements like columns and lead to complete collapse of the structures."Young's collaborators are Ronald Riggs and Ian Robertson, professors at the University of Hawaii at Manoa, and Solomon Yim, a professor at Oregon State University. The team members will publish their work in an upcoming special edition of the Journal of Waterway, Port, Coastal and Ocean Engineering.
One of Young's favorites is a photograph of a stack of delicate unchipped china that survived the storm completely unharmed. All that remains of the church where the china was used is a bent steel frame. "You have to appreciate the irony of nature," Young said. "Most of the time, the scenery is tragic, ironic, and beautiful all at the same time."
One of the group's interesting research findings from the Mississippi work has to do with a phenomenon better known for occurring in neither hurricanes nor tsunamis but, rather, earthquakes. That is something known as "liquefaction." As the storm surge recedes, the sudden decrease in downward pressure on the saturated soil causes the sand to liquefy and flow out like a heavy slurry. This can lead to the eventual collapse of buildings, highways, or bridge abutments, as well as gigantic potholes along coastal roads.
The team was award a NSF NEES-SG grant to study the effect of tsunamis on engineered structures. The final goal of the project is to develop design recommendations to enhance the safety of coastal infrastructures subject to tsunamis.
"If you consider the gravitation, wind, seismic and wave forces, as well as the surrounding soil composition, a building can be designed such that it should be available for immediate occupancy after a minor event, and be able to remain structurally intact to allow for safe evacuation during a Category 3 hurricane like Katrina," said Young.
Understanding how to build hurricane-resistant buildings is one thing; getting society to implement that knowledge is quite another, Young said. "Politics and human values come into play," she said. "People are resilient and have short memories and think that if another hurricane comes along they can just rebuild. I admire their strength but at the same time there is a certain stubbornness about not learning from past mistakes. People like to do what they did before because it's easier than fixing the root of the problem."
Last week, Young gave a presentation on her research at the Massachusetts Institute of Technology. She will also be giving presentations at the Oregon State University, California Institute of Technology, the University of Southern California, and the University of California at Berkeley. "We hope to present our findings widely so that engineers can learn from this and modify future design codes to minimize damage," she said.
Teresa Riordan | EurekAlert!
Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
18.10.2017 | Materials Sciences
18.10.2017 | Physics and Astronomy
18.10.2017 | Physics and Astronomy