Student uses ground penetrating radar to text thickness of concrete in downtown Lowell Image by Tzuyang Yu
UMass Lowell graduate student Tek Dhant, center, uses a ground penetrating radar (GPR) device to test the thickness of the concrete slabs on Central Street in Lowell for the city on April 23. Undergraduates Yaneliz Garcia Ruiz, left, and Tiana Robinson, right, assist.

05/18/2021
Lowell Sun
By Amy Sokolow

LOWELL — UMass Lowell Civil Engineering Professor Tzuyang Yu tells his students that our infrastructure — our bridges, our roads and our buildings — are like engineers’ “unconscious patients,” he says. “We create them, we ought to be taking care of them.”

That’s why his class, “Inspection and Monitoring of Civil Infrastructure,” teaches students how to use sophisticated tools to monitor infrastructure, and he uses the city of Lowell as his laboratory.

“Traditionally, civil engineering students are only prepared for design and analysis of structures,” he said. “That means we are the creator of these infrastructure systems, but to some point, we don’t understand how they deteriorate, and we don’t know how to manage these infrastructure systems in their lifecycle.”

The impetus of the course arose when Yu was working on a project using sensors to monitor infrastructure with the Department of Transportation. Once he finished the project, the agency asked him to apply the technology to structures around him in his neighborhood. Yu then approached the City of Lowell with the idea to volunteer his services, and the team at the city’s engineering department was excited to have a volunteer for this work.

Yu has now done several projects, funded by organizations like DOT, the National Science Foundation and the National Institute of Science and Technology, to analyze structures in Lowell and beyond.

Yu uses a variety of technologies to do this work, including ultrasonic waves, thermal infrared sensors and electrical sensors. He has also used drones to take photos of bridges on the Lowell Connector, which were then used in 3D models by DOT to track the condition of other bridges. Most cities, and even some states, don’t have access to the technologies he uses. He added that his volunteer work circumvents the need for service contracts, which can take years to fund and execute for cities.

As an academic, Yu said it’s easy to get caught up in theory rather than reality. While he was more interested in learning about the composition of the concrete slabs he was measuring for the city, its engineers were simply interested in the thickness of the slabs, which in turn signals how urgently repairs are needed.

Although Yu said that his research interests can sometimes be at odds with the city’s needs, “the bottom line is, I want to make sure that our research efforts can be … useful to the city and to the public,” he said, and added that he’s learning from the city’s needs as well.

Yu doesn’t work on this monitoring alone. Students from his “Inspection and Monitoring” class, as well as students from his research group, the UMass Lowell Structural Engineering Research Group, are helping out.

The group has worked on several projects, including monitoring the Lowell Connector and Plain Street bridges, as well as measuring the thickness of some of the concrete slabs on the city’s sidewalks, including on Central Street.

The group has used tools including ground penetrating radar (GPR) to test the thickness of various concrete slabs, and ultrasonic radar, similar to what pregnant women use at the doctor’s office, to gather information about what types of objects may be underground.

When the group was scanning an area outside Central Street late last month, they noticed that a corner of one of the slabs was missing, exposing the hollowness underneath. When Yu asked the owner of the abutting shop about it, he said it was likely a coal vault underground, which was used to transport coal beneath the snowy roads over 100 years ago. If Yu gets the shop owner’s permission, he said he wants to take a specialized camera underground to see what’s left of the system under the shop.

The undergraduate and graduate students learn how to apply the skills they’ve learned outside of the classroom, which comes with its own set of challenges. Often, there’s litter or other debris on the ground, or the surface isn’t clean. Yu then teaches students how to work on the fly and adapt to the situation in front of them.

“They told me that they actually like doing this kind of thing outside because it’s civil engineering — they get to see the real structure, they get to meet people,” he said. “The only problem with bringing students to the field is that they don’t want to come back!”

The students agree that this has been an invaluable experience for them as they prepare for the workforce.

Tek Dhant, a recent graduate from the civil engineering master’s program who’s originally from Nepal, said he didn’t get to do field work of this nature as an undergraduate student.

Dhant called it “extraordinary” that the group was able to detect small natural cracks in infrastructure with GPR, which he said has never been done before with the device he used. Other researchers previously made artificial cracks to conduct their testing. In his testing, he said the data the group gathered mostly matched their expectations.

As he looks for jobs in New England, he’s hopeful this experience will boost his resume to the top, given the U.S.’s aging infrastructure.

“I really like that I can gain that experience and learn how to use (that equipment) because I might use them in my future job,” said Yaneliz Garcia Ruiz, a civil engineering major, originally from Salem, N.H., who will be a junior in the fall.

She said she was able to share this experience when she was interviewing for internships, and will be working at the Lowell location of Niche Engineering this summer. (Garcia Ruiz also runs the research group’s Instagram account, @uml.serg, which stands for the UMass Lowell Structural Engineering Research Group.)

She said this experience has also been particularly helpful during the pandemic to get out of the virtual classroom and into the real world. She added that she enjoys working where she lives. “By giving back to the city, I’m giving back to UMass Lowell, she said.

“It’s just making… a better, safer city for everybody to come and study,” she said.