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: Quantum Matter Stuck in Unrest

Using ultracold atoms trapped in light crystals, scientists from the MPQ, LMU, and the Weizmann Institute observe a novel state of matter that never thermalizes.

What happens if one mixes cold and hot water? After some initial dynamics, one is left with lukewarm water—the system has thermalized to a new thermal...

Im Focus: On the crest of the wave: Electronics on a time scale shorter than a cycle of light

Physicists from Regensburg and Marburg, Germany have succeeded in taking a slow-motion movie of speeding electrons in a solid driven by a strong light wave. In the process, they have unraveled a novel quantum phenomenon, which will be reported in the forthcoming edition of Nature.

The advent of ever faster electronics featuring clock rates up to the multiple-gigahertz range has revolutionized our day-to-day life. Researchers and...

Im Focus: Superfast fluorescence sets new speed record

Plasmonic device has speed and efficiency to serve optical computers

Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.

Im Focus: Unlocking the rice immune system

Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight

A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...

Im Focus: Smarter window materials can control light and energy

Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.

By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Euro Bio-inspired - International Conference and Exhibition on Bio-inspired Materials

23.07.2015 | Event News

Clash of Realities – International Conference on the Art, Technology and Theory of Digital Games

10.07.2015 | Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

 
Latest News

Tool making and additive technology exhibition: Fraunhofer IPT at Formnext

31.07.2015 | Trade Fair News

First Siemens-built Thameslink train arrives in London

31.07.2015 | Transportation and Logistics

California 'rain debt' equal to average full year of precipitation

31.07.2015 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>