PITTSBURGH (Jan. 27, 2020) — The
Commonwealth of Pennsylvania maintains over 25,000 bridges, and the average
age of those bridges is 50 years, with a significant portion of them in poor
condition. Making sure these bridges are safe is a vital job, but it’s also a
dangerous one: Every year, an
estimated average of 23 bridge
inspectors of state Departments of Transportation (DOTs) lose their lives on
the job, highlighting the need for an automated inspection method that is safe,
accurate and efficient.
Amir Alavi, PhD, assistant professor of civil and
environmental engineering at the University of Pittsburgh’s Swanson School of
Engineering is undertaking a $200,000 project sponsored by the Impactful
Resilient Infrastructure Science and Engineering (IRISE) Consortium at Pitt for
work that will improve bridge assessment. IRISE is a public-private consortium
focused on solving infrastructure durability problems. Its members are Allegheny County, Golden Triangle
Construction, Michael Baker International, the Pennsylvania Department of
Transportation and the Pennsylvania Turnpike.
Alavi’s research will integrate three bridge assessment
techniques: structural health monitoring (SHM), non-destructive evaluation
(NDE) and visual inspection using unmanned aerial vehicles (UAVs), or drones.
The study will establish a data fusion framework to identify the synergies among
bridge degradation, remaining service life, and the SHM, NDE and UAV-collected
data.
Though using UAVs is an emerging civil infrastructure
inspection method, it is presenting its own challenges. In the arena of bridge
inspection, one of the unanswered questions is how DOTs can integrate the UAV
systems with NDE techniques to additionally track deterioration at a higher
temporal resolution, or the frequency at which data is collected, improving
service-life models forecasting.
“We have tons of systems collecting different type of information
about the condition of the civil infrastructure systems and, in particular, our
bridges. However, the problem is how to combine this information to give
inspectors a more descriptive picture of the health status of the bridge,” says
Alavi. “While one method can offer a better temporal information, the other may
provide better spatial resolution, giving more visual detail but less
frequently. One of our primary goals is to identify the level of unique
information provided by each data modality and then fuse the data with various
levels of spatial and temporal resolution to help bridge inspectors make better
decisions more efficiently.”
To pursue this research, Alavi and his team will collaborate
with the Center
for Advanced Infrastructure and Transportation (CAIT) at Rutgers University,
along with industry partner Wiss, Janney,
Elstner (WJE) Inc. It will leverage the data collected by Rutgers’ Bridge Evaluation
and Accelerated Structural Testing (BEAST) facility, the world’s first
full-scale accelerated testing facility for bridges.
The team at the BEAST will monitor a multi-girder steel
composite bridge that is 30 by 50 feet. They will expose the bridge to rapid-cycling
environmental changes and extreme traffic loading to speed up the bridge’s
deterioration, even undergoing simulated winter road maintenance treatments.
Over the nine- to 12-month period, the bridge will go through the equivalent of
15 to 20 years of wear and tear. Alavi’s team will evaluate the resulting data to
look for correlations between the SHM, NDE and UAV-collected data through the
full-life cycle of bridge performance from the first day of service until to
the point that the bridge will be functionally deficient and out of service. The
team plans to build a layered heat map, stacking the data from each method to
provide a more efficient picture of the bridge’s health and potential issues.
The goal of the research is for PennDOT and the other IRISE public
partner agencies to implement the framework, gaining valuable information that
will inform how—and how often—bridge inspectors should use the various
modalities to monitor bridge health.
“Understanding bridge condition is a critical aspect of
infrastructure durability,” says Julie Vandenbossche, PhD, director of IRISE
and William Kepler Whiteford professor of civil and environmental engineering
at Pitt. “We’re pleased that Dr. Alavi’s work will improve the state-of-the
practice in how those conditions are assessed.”
The team will address the reliability of the UAV-based
assessment as compared to the commonly-used NDE methods.
“The autonomous robotic inspection is the future of bridge
inspection, and UAVs play a key role in this game. The problems we are facing for
a wide application of UAVs are basically technological issues,” says Alavi. “There
are solutions, it’s only a matter of time and research, and our research is a step
in the right direction for an effective UAV implementation for bridge inspection
in Pennsylvania and beyond.”
Maggie Pavlick, 1/27/2020
Contact: Maggie Pavlick