Featured Research

from universities, journals, and other organizations

Mimicking fish and tailoring radar to warn of bridge peril

Date:
September 1, 2010
Source:
Case Western Reserve University
Summary:
Researchers have built a pair of sensors to provide real-time risk assessments of bridges during flooding -- the largest cause by far of bridge failure.

Floods cut down more bridges than fire, wind, earthquakes, deterioration, overloads and collisions combined, costing lives and hundreds of millions of dollars in damage.

The speed and turbulence of an overflowing stream scours away the river bottom that provides the support for a bridge foundation, causing more than 60 percent of bridge failures in the U.S. in the last 30 years.

Currently, "there is no way to determine risk during these crucial events," said Xiong "Bill" Yu, an assistant professor of civil engineering at the Case School of Engineering.

To change that, Yu has begun designing what he calls smart infrastructure: underwater sensors that relay real-time information about how much river bottom has been stripped away and how stable, or unstable, the supports of a bridge remain. His work is being funded by a $450,001 CAREER grant received from the National Science Foundation in 2009.

"We don't fully understand how scouring takes place," Yu said. Water passing a bridge support forms vortices, which erode the river bottom. But how and at what rate scour occurs is complex. River bottoms usually consist of sand, clay, shale or sandstone or a mix, and each material acts a little differently in a strong current, he explained.

To characterize each vortex, Yu's lab is building flow sensors based on tiny, hair-like sensors that salmon have on the sides of their bodies. Researchers have found the fish determine flow direction by the direction the hairy cells move and speed by the time delay as turbulence passes different sensors. Yu's lab built sensors comprised of micro pillars made with piezoelectric fibers mounted on flexible copper rods. The fibers produce electric signals reflecting flow direction and speed. These have proven sensitive and accurate; the lab is now developing arrays for real-time flow and turbulence sensing.

To determine the amount of sediments being scoured away, his lab has built sensors that constantly measure the topography where the water meets the river bottom around the bridge supports. These sensors employ a technology called time domain reflectometry, in which radar is fired along waveguides installed at critical ground locations. The electromagnetic waves return at different speeds depending on the materials they strike and distance traveled. The waves are analyzed with an algorithm developed by Yu's lab to reveal minute changes in the depth and density of the substrate sediments.

The sensors proved durable, sensitive and accurate when tested on bridge supports 10-20 feet below the surface. The next step is to determine the maximum depth and flow conditions under which the sensors provide accurate and immediate information.

Yu's lab is also investigating sensors that can monitor the stability of the bridge structure itself.

The package of sensors will provide warnings not currently available and enable Yu's lab to develop computational scouring models and effective scouring countermeasures.


Story Source:

The above story is based on materials provided by Case Western Reserve University. Note: Materials may be edited for content and length.


Cite This Page:

Case Western Reserve University. "Mimicking fish and tailoring radar to warn of bridge peril." ScienceDaily. ScienceDaily, 1 September 2010. <www.sciencedaily.com/releases/2010/09/100901091947.htm>.
Case Western Reserve University. (2010, September 1). Mimicking fish and tailoring radar to warn of bridge peril. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2010/09/100901091947.htm
Case Western Reserve University. "Mimicking fish and tailoring radar to warn of bridge peril." ScienceDaily. www.sciencedaily.com/releases/2010/09/100901091947.htm (accessed July 23, 2014).

Share This




More Matter & Energy News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins