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Rensselaer Civil Engineers Help Destroy Test Levee in The Netherlands

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Engineers Collect Data to Inform and Validate
New Suite of Technologies for Assessing the Health of Levees
and Dams

Civil engineers from Rensselaer Polytechnic Institute
were part of an international research team that collapsed a
full-scale dike this week in The Netherlands. The test dike was
embedded with advanced sensors and traditional measurement
instruments, and results of the study are expected to help
validate powerful new technologies for monitoring the health of
aging flood-control infrastructure.

The dike was situated in a specially constructed basin,
which the researchers filled with water. The slow addition of
water into the basin increased the pressure on the dike. Water
forced its way into the dike, and eventually softened the
bottom of the dike and shifted the earth underneath, prompting
the overall structure to collapse. The study was led by Dutch
research institute Deltares, in partnership with Rensselaer and
14 other companies and universities from around the world. It
was the research team’s third full-scale levee test collapse
this summer. The full results of the tests will be presented at
the Flood Risk Conference in November 2012 in Rotterdam, The
Netherlands.

“The failure of flood-control infrastructure is very real,
and can lead to catastrophic flooding as we unfortunately
witnessed in 2005 during Hurricane Katrina,” said Tarek Abdoun,
associate dean for research and graduate programs in the School of Engineering and
the Judith and Thomas Iovino ’73 Career Development Professor
in the Department of Civil and
Environmental Engineering at Rensselaer. “A large-scale
test like this can help supply us with invaluable data to
inform and validate our efforts to create a long-term,
real-time monitoring system that can assess the health of
levees and help identify the vulnerability of levee or dam
sections before they fail.”

Rensselaer Research Assistant Professor Victoria Gene
Bennett and Associate Professor Mourad Zeghal are
collaborating on the project with Abdoun. Their participation
in the Deltares project was funded as part of a three-year
grant from the U.S. Department of Homeland Security’s Science
and Technology Directorate. Abdoun, Bennett, and Zeghal are
faculty members of the Rensselaer Center for Earthquake
Engineering Simulation (CEES), which is a part of the George E. Brown, Jr. Network for
Earthquake Engineering Simulation (NEES) Program of the National Science
Foundation.

The collapsed dike was fit with a large number of different
sensors, including SAPP (shape-acceleration-pore pressure)
arrays that were developed through a partnership between
Rensselaer and industrial collaborator Measurand. SAPP sensor
arrays are designed to be installed into the ground, beneath
and around levees and dams. The cost-effective arrays
accurately measure soil deformation, vibration, and pore
pressure at critical points of a flood-control system.

These SAPP arrays are a critical part of an ongoing
Rensselaer-led research project to create an integrated suite
of technologies and methods for ensuring the reliability and
safety of flood-control infrastructure. The project, funded by
the U.S. National Institute of Standards and Technology’s
Technology Innovation Program, pairs SAPP measurements with GPS
and InSAR, or satellite-based interferometric synthetic
aperture radar measurements. Accurate down to the millimeter,
InSAR captures and analyzes high-resolution satellite images of
levees and dams, and measures how far these structures have
shifted or sunk due to environmental changes such as rain,
floods, tremors, or even aging. To bridge the gap between InSAR
satellite data and below-ground SAPP measurements, the
researchers will augment the framework with a network of
high-resolution GPS sensors to track the physical movement of
structures and the ground surface.

“Through our joint venture partnership with Geocomp Corp., a
dense grid of instruments including SAPPs, GPS, and radar
reflectors has been installed at the London Ave. Canal in New
Orleans. The real-time data collected from this site, and
others in the New Orleans area, will make performance
information available during this and upcoming hurricane
seasons, in addition to providing calibration data for health
assessment algorithms,” Bennett said. Led by Zeghal, this
project is a collaboration with Bennett, Abdoun, and Birsen
Yazici, professor in the Department of Electrical,
Computer, and Systems Engineering and the Department of Biomedical
Engineering at Rensselaer.

Data collected from the SAPP, InSAR, and GPS systems are
integrated into an automated “smart network” that provides a
long-term continuous assessment of the health of levee systems
from both underground and aerial perspectives. In the case of a
levee failure, data collected by the automated monitoring
system will be used to organize a quick emergency response to
repair levees and minimize the extent of flooding. Collected
data is also being paired with computational simulation
techniques to build accurate, predictive models of how
different levees will react to different environmental
conditions. These models help inform plans to mitigate levee
damage and respond to disasters, and provide quantitative
assessments that will better allow federal and local
governments to prioritize where infrastructure repairs are most
needed.

In the United States, the national flood-control
infrastructure is aging and its structural health is
deteriorating, Abdoun said. The system is comprised of more
than 5,600 km of levees, and 43 percent of the U.S. population
lives in counties with levees designed to provide some level of
protection from flooding. Some of these levees are as old as
150 years. In 2009, the American Society of Civil Engineers
Report Card for America’s Infrastructure gave the condition of
the nation’s dams a grade of D, and levees a grade of
D-minus.

For more information on Abdoun’s research at Rensselaer,
visit:

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