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!
Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main
Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy