Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

‘Shaky’ Plan: Quake Experiments May Lead to Sturdier Buildings

17.12.2010
Cold-formed steel has become a popular construction material for commercial and industrial buildings, but a key question remains: How can these structures be designed so that they are most likely to remain intact in a major earthquake?

To help find an answer, Johns Hopkins researchers have been awarded a three-year $923,000 National Science Foundation grant to study how seismic forces affect mid-rise cold-formed steel buildings, up to nine stories high.

The work will include development of computer models, as well as testing of two-story buildings placed atop full-size “shake tables” that replicate forces up to and greater than those of any modern-day earthquake.

Lead researcher Benjamin Schafer of the university’s Whiting School of Engineering said there is a critical need for the data these experiments should yield.

“We do have a conservative framework for how to build cold-formed steel structures to withstand earthquakes, but we don’t have all of the details,” said Schafer, the Swirnow Family Scholar Professor and chair of the Department of Civil Engineering. “Beyond avoiding complete collapse, we don’t know how a lot of building materials will be damaged when certain levels of earthquakes occur. Information gaps exist for a lot of building materials, but the gaps for cold-formed steel are really big. We’re trying to fill in some of those gaps in knowledge.”

The cold-formed steel pieces that are commonly used to frame low- and mid-rise buildings are made by bending about 1-millimeter-thick sheet metal, without heat, into structural shapes. These components are typically lighter and less expensive than traditional building systems and possess other advantages. For example, cold-formed steel pieces are more uniform than wooden components and do not share wood’s vulnerability to termites and rot. Cold-formed steel also is considered a “green” material because modern producers use 100 percent recycled metal.

Structural engineers who design cold-formed steel buildings need more information about how the material will perform during earthquakes, Schafer said, in part because of revised thinking in the construction industry.

“The old approach was to just make sure the building didn’t fall down in an earthquake, even if it was no longer safe or was too badly damaged to be used afterward,” he said. “Now, we’re focusing on what you can do to bring it up to a higher level of performance to make sure that the building can still be used after an earthquake, when desired.”

Some of the motivation for this is coming from the insurance companies and business owners who are economically tied to such structures. If a critical warehouse or a major customer service center can continue to operate after an earthquake, the business owners will likely incur lower losses.

“For this reason, a sturdier building can lead to lower insurance rates and provide a level of business confidence for certain owners,” Schafer said.

But how can a business owner or insurance company predict how well a cold-formed steel building will stand up to an earthquake? Current estimates rely on a technique that tests how quake-like forces affect a single portion of a wall. Schafer’s study, in contrast, will treat the structure as a full system that includes complete walls, floors, roofs, interior walls and exterior finishes, all of which can contribute to how well the building stays intact when severe shaking occurs.

To compile this data, Schafer and his colleagues will test building components in a structural engineering lab at Johns Hopkins. They will also develop computer models aimed at predicting how well these building components and structural designs will resist earthquake forces. In the third year of the study, the researchers will conduct full-scale building experiments at the Network for Earthquake Engineering Simulation equipment site at the University at Buffalo, State University of New York. This site has full-size shake tables that will allow the researchers to mimic the effect of an earthquake on various configurations of multi-story cold-formed steel framed buildings.

“We will attempt to ‘fail’ the buildings,” Schafer said, meaning that the level of shaking will increase until the buildings collapse. The goal will be to find structural designs that hold up at the level of the most severe modern-day earthquakes.

“The ultimate purpose of this project,” he said, “is to give structural engineers better tools to make predictions about what will happen to cold-formed steel buildings in an earthquake. That will give them more flexibility to design the whole building and will give them the validation to know that it will stand up to a certain magnitude of earthquake forces.”

Schafer’s collaborators in the study include Narutoshi Nakata, an assistant professor of civil engineering at Johns Hopkins; a Bucknell University team led by Stephen G. Buonopane, an associate professor of civil and environmental engineering who earned his civil engineering doctorate at Johns Hopkins; researchers from McGill University in Canada; and professional engineers from Devco Engineering, based in Oregon. Additional funding and support will be provided by the American Iron and Steel Institute and by Bentley Systems, a developer of engineering software.

As part of an outreach effort, students from Johns Hopkins, Bucknell University and Baltimore Polytechnic Institute also will take part in the research project.

Related links:
Research Project website: http://www.civil.jhu.edu/cfsnees/
Benjamin Schafer’s website: http://www.ce.jhu.edu/bschafer/
Narutoshi Nakata’s website: http://www.ce.jhu.edu/nakata/
Department of Civil Engineering: http://www.civil.jhu.edu/

Phil Sneiderman | Newswise Science News
Further information:
http://www.jhu.edu

More articles from Architecture and Construction:

nachricht Smart buildings through innovative membrane roofs and façades
31.08.2017 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

nachricht Concrete from wood
05.07.2017 | Schweizerischer Nationalfonds SNF

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: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

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...

Im Focus: Breaking: the first light from two neutron stars merging

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....

Im Focus: Smart sensors for efficient processes

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...

Im Focus: Cold molecules on collision course

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>