Many of this year’s graduates in the UVM civil and environmental engineering program faced an added degree of difficulty in their senior capstone course: designing renovation projects without actually seeing the existing structures.
The COVID-19 pandemic this year made it impossible for students to make site visits. But engineers, after all, are trained to be problem solvers.
Working with photos, historical records and self-constructed computer models students developed design solutions that may one day save a historic covered bridge from the next tropical storm, or preserve and repurpose a long-abandoned structure with an iconic presence in a northern Vermont village.
Professor of Practice John Lens, instructor for the course, says the senior capstone not only gives students a chance to tackle a real-world challenge, but results in projects that actually get built.
“There’s a strong service-learning component to the course,” Lens explains. “Our students work with clients—town managers or non-profit leaders or citizen groups—that are looking for design solutions.”
Students provide clients with an engineering study, plans and cost estimates of alternatives, which the clients can then use for hiring a professional engineering firm to draft a fully developed set of construction plans.
This year Lens drew on his extensive connections in the state and from the UVM Office of Community-Engaged Learning (CELO) to identify community partners. Seven of the 13 student projects in this year’s course involved preserving historic structures.
“Naturally the students were disappointed not being able to visit the sites,” Lens said. “But we were fortunate this year, especially with these historic projects, that there was strong community interest. As a student, you can see how you can make an immediate contribution that’s very appreciated and very tangible.”
Bridge over troubled water
One of oldest, still intact covered bridges in Vermont straddles the Mad River in the town of Warren. The bridge is listed on the National Register of Historic Places but it nearly met its demise in the flooding that followed Tropical Storm Irene in 2011.
“It’s a queen post bridge built in 1880,” explained Sam Langeleh, a civil engineering graduate. “The goal of the project was to mitigate the flood risk and prevent the overtopping that was seen in Tropical Storm Irene from happening again.”
She teamed up with fellow seniors Ashlie Mercado (civil engineering), Linh Nguyen (civil engineering), Colin Palmer (civil engineering) and Reed Winter (environmental engineering). The group’s design solution had to thread the needle between structural viability and maintaining the historic character of the bridge.
J.B. McCarthy ’79, bridge preservation engineer for the Vermont Agency of Transportation, served as one of the consultants on the project. McCarthy sits on the UVM civil and environmental engineering department’s board of advisors and has helped provide many students with internships at VTrans.
“The issues with the Warren bridge have had to do not so much with the structure itself—the bridge is still in pretty good shape—but with the Mad River,” McCarthy said. “Bridges with a short span like this tend to narrow the river’s flow.”
The original bridge abutments on both banks were built far out into the water, narrowing the channel which factored into high flood waters during Irene. The increased water velocity over the years has also eroded the stability of the abutments.
The students settled on a design that calls for building new abutments closer to each bank, effectively widening the river at the bridge. New cantilever beam supports reaching to the existing bridge from each abutment will hold the structure further away from each side.
“Hydraulicly the bridge is 14 feet narrower than the river’s natural channel width,” Winter reported in the group’s final presentation. “Changes to the width of the waterway opening at the abutments would drop the water surface elevation by six feet and assure that the river would not overtop the bridge deck.”
The group’s final cost estimate for the project was $1,204,000, well north of the town’s current budget of $375,000 for the bridge’s replacement. But grants from the Preservation Trust of Vermont or FEMA's Environmental & Historic Preservation program could potentially fill that gap.
“I think the plan does a great job balancing the need to keep the bridge structure itself unchanged, while accounting for flooding that will likely increase in the future,” McCarthy said.
Second life for Hardwick granite shed
Vermonters are well versed in the history of the granite industry centered around quarries in the Barre, Vt., area. Granite was also a major industry in the town of Hardwick, about 30 miles to the north. Hardwick granite was used to build dozens of prominent buildings including the Pennsylvania capitol building in Harrisburg and Chicago City Hall.
The granite industry eventually dried up, leaving behind granite shed number 4, a 100-year-old wooden structure 40 feet wide and 350 feet long. The shed was a sheltered construction space and trains ran through the length of the building to transport the granite along the old Lamoille Valley railroad.
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Though long abandoned, the building’s long, low profile has become a familiar part of Hardwick’s built landscape.
Local residents like Bethany Dunbar, community programs manager for the non-profit Center for an Agricultural Economy (CAE) in Hardwick, sought input from other local stakeholders holders to figure out potential uses for the building.
“Hardwick used to be known for granite. Now it is known as a hub for local food, food access and farm viability,” she explains. CAE acquired the shed in 2008 and Dunbar foresees an exciting future for the structure as a farmer’s market and a venue for recreational activities.
But the building needs help.
Matt Smrtic, a graduate on UVM’s civil engineering program, summed up the restoration challenges this way: “The shed is deteriorating and unstable as it sits now. The framing is rotted, the foundation is not suitable, and current design does not withstand the loads expected in the ever-changing environment in the northeast.”
“There isn’t a straight line in the place,” noted Lens.
Another complication is that the building lies in a flood plain, a cause of much of the wood rot.
Like their counterparts working on the Warren project, students couldn’t get a first-hand look at the structure due to COVID-19 travel restrictions. Collaborating online, Smrtic and his fellow civil engineering majors Oliver Anderson, Brennan O’Neil and Paula Statskey developed a restoration plan that retains the shed’s integrity while providing repairs and upgrades that the students say will give the building a long second life.
Foundation repairs include installation of concrete piers under each wall post to provide support and prevent shifting. Flood vents will regulate the flow of water under the building during high water events. Granite blocks making up the original foundation have sunk or shifted over the years. These will be leveraged back into place between concrete piers to recreate the original appearance.
The students recommended adding more natural light by adding four more barn doors, two on each side, and filling empty window casings with double-hung windows. Interior lighting will be powered by a solar panel array installed on the roof, making the building energy self-sufficient.
The students ballparked a total price tag of materials at about $300,000. Dunbar and her CAE colleagues can’t wait to get started on the fundraising phase to make the vision a reality.
“This project has helped so much in putting us on a faster track,” she said. “The students showed us how to rehabilitate the structure in such a way that makes it functional for years to come without sacrificing its character.”
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UVM Civil and Environmental Engineering Senior Capstone Design Projects, Spring 2021
Waitsfield Bridge Flood Hazard Mitigation: Mitigating the flood hazard to this historic covered bridge and adjacent village area (Waitsfield)
Warren Covered Bridge Flood Hazard Mitigation: Mitigating the flood hazard to this historic covered bridge and adjacent village area (Warren)
Otter Creek Wetland Restoration: Restoring former farmland to riverside shrub-scrub wetland by altering drainage ditches (Brandon)
Randolph Meetinghouse Sustainability Design: Protecting this 220-year-old timber frame with structural, site and foundation drainage, and improvements (Randolph)
EPA Campus Rainworks-Stormwater, Blue Team: Master planning for sustainable stormwater mitigation for 100-acre main (north) campus (Burlington)
EPA Campus Rainworks-Stormwater, Aqua Tea: Sustainable stormwater design for the Redstone Green area, the last UVM campus parcel without stormwater mitigation (Burlington)
Kent's Corner Barn Sustainability Design: Protecting this historic timber frame for structure and fire resiliency and more active use (Calais)
Kent's Corner Inn and Store Sustainability Design: Historic structure improvements for accessibility, sustainable energy use, and preserving the timber framing from interior moisture (Calais)
Aldrich Sawmill Early Water Power Demonstration Project: Designing site and penstock for demonstrating an early horizontal turbine powered sawmill without stream impacts (Calais)
Microplastics pollution mitigation: Mitigating microplastic pollution in water as generated through washing synthetic fabrics
Atkins Field Granite Shed Reuse Design: Restoring a 150-year-old timber granite manufacturing shed for community use in a flood hazard area (Hardwick)
Atkins Field Community Building and Parking Design: Designing a community center building with expanded parking in a flood hazard area (Hardwick)
Forested Multi-Use Trail Design: Designing a sustainable multiple-use trail through rugged forested terrain (Burlington)