How do you protect older downtown Corvallis buildings from a catastrophic earthquake? How do you do the retrofit without destroying the historical integrity of the building? Is there a way to do the work using new technology such as cross-laminated timber? And how can a success here be replicated somewhere else?
That’s what a team of engineers, architects, contractors, preservationists and Oregon State University faculty and students is trying to figure out.
Using a $98,000 grant that the Downtown Corvallis Association received from Oregon Main Street plus private matching funds and in-kind services, the group is targeting the Harding Building at the corner of Southwest Madison Avenue and Third Street — the home of the Footwise shoe store.
Recently, the Gazette-Times received a tour of the building as group members brainstormed their first major objective, a mock-up for how the project goals can be accomplished. And because one of their goals is to record the twists and turns of the project so that others can benefit from the process, videographers Austin and Garrett Baker were weaving their way through the tour with their camera lights on.
“We have to mock it up in a way that doesn’t impact the structural integrity of the building,” said contractor Warren Lisser.
Peter Wendel, the building’s owner, called the task a chicken-and-egg challenge. “It’s not a proven technology,” he said. “We’re trying to be the guinea pig.”
Using cross-laminated timber, an engineered wood product that involves gluing boards together at perpendicular angles to increase structural strength, in such a project is a whole new ballgame.
Architectural historian Roz Keeney and OSU Professor Andre Barbosa said that it is the first time the technology has been tried in the United States on unreinforced masonry (URM) buildings.
Barbosa, who also works with Cascadia Seismic Strategies, has studied the impact of large earthquakes on URM buildings and presented some of his data at a Corvallis City Club meeting in March 2017 on a panel that also included Lisser.
“Hopefully,” said project manager Sue Licht, “we’ll have a system design for this building, we’ll know the costs and whether it will be a good fit for historic structures. This is really new.”
The team then moved into a heavily windowed section of the vacant second floor of the building and began problem-solving. How will they work around the URM piers? How will they keep the building in “balance,” as it is put by engineer Reid Zimmerman of KPFF Engineers.
“We’re still developing ideas and concepts,” Zimmerman said. “This is a little bit like sausage being made.”
The team also discussed whether mass plywood panels, another new engineered-wood product, could play a role. Both mass plywood panels and cross-laminated timber have received a strong boost from research and partnerships involving OSU.
Zimmerman also noted that some of the work the project likely will require involves “technology that wood framers aren’t used to doing.” Materials storage might be an issue. How do you get large pieces of cross-laminated timber and mass plywood panels into the building and in place? The team discussed the possibility of using the building’s windows to bring in materials.
“It’s more complicated to do mock-ups than the real thing,” Zimmerman said. “The goal is to show that it can be done. It doesn’t have to be functional.”
Licht estimates that the team will start the actual physical mock-up this spring, with final completion of the project, which might require more grants, at least two years away.
The group also said it is keeping the economic development piece in mind.
“We want the building to be here after a quake,” Keeney said. “The core needs to be saved if at all possible and rebuilt after a big event.”