Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cargo container research to improve buildings' ability to withstand tsunamis

06.02.2013
Anyone who has seen the movie "Impossible" or watched footage from the Japanese tsunami has learned the terror that can strike with little warning. In those cases, when there is no time to flee, there may still be time to reach higher ground, called vertical evacuation.

But as you race to the third floor, how do you know if the building will hold up? Walls of water are not the only danger. Another potentially lethal challenge is water-driven debris - such as 60,000-pound fully loaded cargo containers - transformed into projectiles. Often pulled behind semi-trucks on highways, these containers that line port areas well exceed the telephone-pole-size 1,000-pound default log assumed by most U.S. building-design guidelines.



A multi-university team lead by Ronald Riggs, a structural engineer at the University of Hawaii, has determined just what the impact could be and will present findings at an international conference in June. The goal is to supply structural engineers with information to design buildings in areas vulnerable to tsunamis.

Currently there are no scientifically tested guidelines. And, as those who survived the Japanese tsunami that swept thousands to their deaths can attest, no one had planned for such force.

"Most structural systems are designed to defy gravity, not a side kick from a shipping container," Riggs says. "An engineer can build what it takes to withstand the karate chop, but first the engineer has to know what forces to expect."

This knowledge is vital not only for the buildings into which people might flee, but also for coastline storage tanks that could spew chemicals or other pollutants if damaged.

Riggs first began thinking about the problem as he examined damage to bridges and buildings following Hurricane Katrina. He noticed the cargo containers and barges that had been flung onto land in areas such as Biloxi, Miss. On another scientific excursion to Samoa, he says he saw a shipping container "whacked against a meeting hall - and there was no port anywhere nearby."

"These shipping containers are surprisingly ubiquitous," Riggs says. The point was further brought home on TVs across the world that played and replayed footage from Tohoku, Japan, as tsunami-fed waters dragged cars, trucks and shipping containers as much as six miles inland and then back out to sea in the drawdown.

"They may have been moving only about 10 miles an hour, but given their weight, this is a significant load for a structure not made for it."

His colleagues and he proposed research to analyze several pieces of the puzzle with the help of the George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES), a distributed laboratory with 14 sites across the country funded by the National Science Foundation. The network, which also funded Riggs' research, provides access to highly specialize, sophisticated and expensive equipment.

For Riggs, two NEES sites were needed. One is at Lehigh University in Bethlehem, Pa., which specializes in real-time multi-directional testing for earthquake simulation of large-scale structural systems. The other is a wave flume longer than a football field at the Tsunami Research Facility at Oregon State University. At the Lehigh site, they swung full-scale wooden poles and shipping containers through the air on a pendulum to determine the force of impact at various velocities. At Oregon State, they ran similar tests at a 1:5 scale, but this time in its large flume wave to see if that made a difference.

His basic assumptions held true, but there were two surprises. First, when the speed of the projectile was the same, the water did not have a significant impact.

"We thought the fact that it was in water would increase the load, but it did not, at least not substantially," Riggs says. "The impact is so short, on the order of a few milliseconds, that in some ways the water doesn't have time to increase the force."

The second surprise was that the weight of the shipping container's contents also did not matter as much as he would have expected. The container itself, which is roughly 20 feet long and weighs about 5,000 pounds empty, could weigh as much as 60,000 pounds when fully loaded. Yet, its load when striking a building was not significantly greater than that of the empty container.

The reason is the same as for the water, Riggs says.

"Unless the contents are rigidly attached to the frame of the container, which they usually are not, the contents also don't have time to increase the force during the very short duration of impact."

The next step for Riggs and his team is to use the preliminary findings to better define building guidelines and policy.

"It's especially important for areas like Japan and the Cascadia area on the West Coast of the United States where tsunamis are most likely to strike with little warning, making vertical evacuation essential," Riggs says. "Or in Waikiki where the population density would make horizontal evacuation (trying to outrun the tsunami) problematic."

Riggs will present the team's findings at the 32nd International Conference on Ocean, Offshore and Arctic Engineering, sponsored by the Society of Mechanical Engineers ASME to be held June 9-14 in Nantes, France. His colleagues are Clay Naito, associate professor at Lehigh University; Dan Cox, professor at Oregon State University; and Marcelo Kobayashi, associate professor at the University of Hawaii.

Contact:
Ronald Riggs, 808-956-6566, riggs@hawaii.edu

Writer:
Jeanne Norberg, 765-491-1460, jnorberg@purdue.edu

Jeanne Norberg | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Architecture and Construction:

nachricht Smarter window materials can control light and energy
23.07.2015 | University of Texas at Austin

nachricht University of Cincinnati, industry partners develop low-cost, 'tunable' window tintings
11.06.2015 | University of Cincinnati

All articles from Architecture and Construction >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Increasingly severe disturbances weaken world's temperate forests

Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.

"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease...

Im Focus: OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.

The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...

Im Focus: What would a tsunami in the Mediterranean look like?

A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).

Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...

Im Focus: Self-healing landscape: landslides after earthquake

In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.

These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...

Im Focus: FIC Proteins Send Bacteria Into Hibernation

Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.

For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

Large agribusiness management strategies

19.08.2015 | Event News

 
Latest News

Production research by Fraunhofer IAO honored with three awards at the ICPR 2015

31.08.2015 | Awards Funding

Single-Crystal Phosphors Suitable for Ultra-Bright, High-Power White Light Sources

31.08.2015 | Materials Sciences

Manchester Team Reveal New, Stable 2D Materials

31.08.2015 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>