Collaborative effort explores moving power lines from overhead to underground

Nearly 12 years ago, an intense windstorm with a funky name – derecho – blew through the eastern part of the United States, including Southwest Virginia.

The storm killed 22 people across seven states, created widespread destruction to homes and businesses, and left more than 4 million people without electricity. In all, the storm caused nearly $3 billion in damages.

Joe Vantassel thinks he, a few of his colleagues, and several other collaborators have a way of keeping the power on while, in turn, significantly reducing those damages when violent storms occur.

An assistant professor in the Charles E. Via Jr. Department of Civil and Environmental Engineering, Vantassel and his team recently were selected to receive a $2.5 million grant from the U.S. Department of Energy through the Advanced Research Projects Agency-Energy to test more efficient ways of burying power lines underground in a safe, cost-effective manner.  

Leaders in many cities and towns already require electric wires to be buried. In fact, the Town of Blacksburg requires it for all new construction. Burying these lines often means using an underground directional boring machine that bores through the soil more than 3 feet deep. The process, called “undergrounding,” alleviates the issue of storms tearing down poles and lines and thus eliminates extensive power outages.

But boring presents challenges, not the least of which is the danger created when machine operators hit unseen existing power, water, and sewer lines.

“It’s not uncommon, unfortunately, to hit things,” Vantassel said. “These things can be other utilities like water mains or gas pipelines or things like that. … When contractors go to install these cables underground and do this horizontal drilling, they oftentimes hit those things. This is, of course, dangerous for the drilling crew, and it can also cause disruptions to other utility services.”

Hitting an existing line means stopping a project first to make repairs, which adds to the cost of the project. Then it requires further investigation to determine if other lines exist within the area, thus delaying a project while also adding to the cost.

So what is the answer to this problem? Well, what if equipment operators could see whatever lies in front of them?

A potential solution

Vantassel’s plan consists of putting sensors on the drill head of the underground directional boring machine and at the ground surface. These sensors capture data and when combined with an artificial intelligence predictive modeling, delivers a 3D view to the operator to see what the drill head sees.

Vantassel compared doing this to a person in the medical profession taking an X-ray or an MRI.

“You get an X-ray or you get an MRI if you're not feeling well because doctors need more information to decide what to do,” he said. “So how do they figure this out? Well, they take an image. In geotechnical engineering, where we're dealing below the ground surface, we have similar needs.

“My hope with my research more broadly is that we advance civil engineering and projects that we're working on just the way medical imaging has with medical science. Where would we be if we didn't have the ability to take an MRI? My hope with my work is that you can make imaging, geotechnical type problems or on the ground surface, just as accessible.”

The concept itself is simple – sensor data with artificial intelligence (AI) prediction rendering a 3D image of the ground for the operator to see. But integrating all the data collected by the sensors poses potential challenges, especially with the team using three modes of sensing. Vantassel hopes to leverage AI predictive modeling to combine the information from the sensing systems.

For additional expertise, he has enlisted a team of experts from the College of Engineering and Advanced Research Computing, including the following:

• Adrian Rodriguez-Marek, professor, geotechnical engineering
• Russell Green, professor, geotechnical engineering
• Rodrigo Sarlo, assistant professor, structural engineering and materials
• Erik Westman, professor, mining engineering
• Matthew Brown, computational scientist, Advanced Research Computing 

Collaborators external to Virginia Tech also will take part:

• Eileen Martin, assistant professor, geophysics and applied math and statistics, Colorado School of Mines
• Karl Warnick, professor, electrical and computer engineering, Brigham Young University

Collaboration with Virginia Tech Electric Service

Rather than spend money on a bunch of equipment to test out theories, Vantassel and his team approached the leadership within the Virginia Tech Electric Service about participating in the project. Virginia Tech Electric Service provides electricity to the campus and to certain parts of Blacksburg and owns an underground directional boring machine. It certainly gets plenty of use. Nam Nyugen, executive director of energy and utilities for Virginia Tech, said that more than 90 percent of campus power lines are underground.

“When they approached us, we were glad to be available to help,” Nguyen said. “We have a lot of stakeholders on campus, and where our experience and expertise are available, we certainly want to collaborate.”

The two parties met, with two linemen from Virginia Tech Electric Service showing several members of Vantassel’s team how the boring machine worked. It features an alarm that goes off when an object is in the area and subsequently shuts down the machine, which prevents the hitting of vital lines. Workers must take the time to find the obstacle, though, and come up with a way to avoid it, either by removing it, boring around it, or boring under it.

The members of Vantassel’s team provided information from their perspectives at this meeting as well, explaining to the linemen what exactly they wanted to do and how to do it – and more importantly, how it could aid everyone.

“With their technology, they were talking about having a virtual view of the area to let the operator see ahead of time and quickly manipulate around obstacles and objects versus having to have two-way communication with someone else or another instrument,” Matt Salmon, engineering manager for Virginia Tech Electric Service, said. “It’ll make things more efficient for us to operate the machine.”

The two sides collectively agreed on the project’s potential and to put their expertise into it.

“If they're going to advance the technology, sure, we’re happy to help,” Chris Cooper, Electric Service supervisor, said. “You're always looking for better things.

“Boring is a challenging job, and it only gets worse as the years go on. You get more utilities underground, so there's more obstacles to clear. Every year, somebody else is putting something in the ground, and it's just something else that you’ve got to avoid if you're trying to do a boring job.”

Next steps

The project is slated to begin in August, which allows the team several months to recruit graduate students to help with tasks. Vantassel and his team plan to use most of the grant money to pay the graduate students.

Vantassel expects the project to last three years. At the conclusion, the group plans to conduct lab-scale testing of the different sensing modalities in the Center for Autonomous Mining.

In summary, Vantassel wants to make undergrounding a safer, more cost-effective process, and in turn, create a more reliable, resilient electrical grid for American consumers.

“If we can bring the cost down to undergrounding, it should be a much easier decision to say, ‘OK, we're going to get a more reliable, a more resilient grid if we underground, and if we can bring the price down sufficiently, then we can compete with overhead lines that need to be constantly prepared and replaced in the long term,’” Vantassel said. “That's really what we're hoping for. I think that advantages everybody.”