Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mimicking fish and tailoring radar to warn of bridge peril

01.09.2010
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.

Kevin Mayhood | EurekAlert!
Further information:
http://www.case.edu

More articles from Information Technology:

nachricht Ultra-precise chip-scale sensor detects unprecedentedly small changes at the nanoscale
18.01.2017 | The Hebrew University of Jerusalem

nachricht Data analysis optimizes cyber-physical systems in telecommunications and building automation
18.01.2017 | Fraunhofer-Institut für Algorithmen und Wissenschaftliches Rechnen SCAI

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>