Civil engineering students help design
replacement for storm-damaged bridge
© Dec. 16, 2011, Norwich University Office of Communications
Thomas Hornstein, an enlisted Marine studying civil engineering at Norwich University, visited the Fairgrounds Bridge in Northfield, Vt., as Tropical Storm Irene began to wane. He lives just up the road.
The bridge, like hundreds after the Aug. 28, 2011, storm that devastated parts of New England, was swamped. Water from the raging Dog River poured over the decking and tunneled behind the concrete abutments, pulling them away from the riverbanks. He immediately assumed the flat, wood-decked bridge was a goner. The flooding was simply too intense.
“There’s no way you can design for that,” Hornstein recalled thinking.
Three months later, however, he is part of a team of students trying to do precisely that. Hornstein and two other seniors are making recommendations to Northfield about the best way to approach a replacement. While the town will hire a professional engineer, it is the students’ hope their assistance will save money, give the town a better sense of its options, and perhaps even result in a final bridge design.
It doesn’t have an answer in the back of the book.
Civil Engineering professor
“It’s going to potentially be our design that’s built,” said Felicia Desorcie, a Westford, Vt., senior who is working with Hornstein and Frank Donato.
The Fairgrounds Bridge crosses the river close to a secondary state highway. It is not an ideal spot for a bridge, but it provides the only access for dozens of homes, and therefore needs to be replaced. A temporary replacement was constructed shortly after the storm, but town employees are worried it won’t hold for long.
“If we get high water, it’s hard to say what will happen,” said Tim Davis, highway foreman for Northfield.
Time is of the essence, but funding is still in question and Northfield employees don’t expect to put construction out to bid until spring 2012. In the meantime, there were questions about the types of abutments, decking material and the bridge design that will work best. At a November 2011 meeting, a major question was whether to keep it in the same location.
“Is there one site you think is the best option?” asked Desorcie, introducing three potential locations they had been working on to two of Northfield’s highway supervisors.
Hornstein piped in that the current bridge location will keep costs down, but may not be the best long-term option. Factors such as usability for trucks and trailers, plowing, ease and speed of construction and whether abutments would “pinch” water flow on the Dog River should be considered.
As the town foremen, students and two Norwich professors probed deeper into the discussion, charts and printouts began to fill the table in front of them. The conversation jumped back and forth between what was best and what was realistic. Eventually, they separated with the location pared down to two possibilities and plans to reconvene later in the winter.
“It’s impressive what you’ve done to date,” said Pete Demasi, Northfield’s highway manager.
Desorcie said she was a bit frustrated they did not settle on a site, which would allow the students to proceed and make better cost estimates. They’re also in limbo until the town has data from soil borings. Working with a client and the realities of municipal projects, she said, has been one of the big challenges of the project.
“There’s definitely been a lot of learning along the way,” she said, “stuff that hasn't been covered in class.”
Hornstein added that as student engineers, they are often confused about when and where it is appropriate to make assumptions. The sheer importance of providing a working bridge, he said, adds an element of pressure and drives home the responsibility to be honest about their limitations.
Civil engineering Prof. Edwin Schmeckpeper said students are often surprised by the constraints they encounter in real projects. It is also the reason that Norwich’s David Crawford School of Engineering works hard to find opportunities for its students to get involved with local service projects.
“It doesn’t have an answer in the back of the book,” he said.
Schmeckpeper said the department immediately looked for ways students could use their senior projects to help the local community following Irene. As many professors pass the Fairground Bridge on their way to work—scarcely a mile from the campus of Norwich, the country’s oldest private military college—this was an obvious possibility. The town seemed eager to collaborate.
“It’s a small enough project that the students have a good chance of coming up with something that is useful,” he said.
Students added it was gratifying to use their skills in a way that may translate into real benefits for a town hard-hit by the storm.
“You can actually feel the effects and help people in a real way,” said Hornstein.