Passing through Newport, you can hardly miss the tall crane and “deep soil mixing drill” injecting cement 100 feet deep under the soon-to-be-poured foundation for Oregon State University’s new Marine Studies Building. Hatfield Marine Science Center Director Bob Cowen said the subsoil strengthening is just one of many reinforcements to help the large, three-story building endure the Big One, a worst-case offshore earthquake.
“We’re looking at having the building survive not only the shaking of a 9.0 [magnitude quake] but also the potential of a tsunami coming through,” Cowen said. “The building has to remain anchored so that the wave doesn’t wash it away.”
As construction progresses next year, you’ll notice a big, broad ramp leading up the outside of the building to a tsunami safe-haven on the roof for up to 900 people. The roof will be at a height of 47 feet, safely above the predicted maximum tsunami height at the Yaquina Bay shoreline.
Cowen said interior stairwells will have extra reinforcement and an elevator shaft will be hardened to an exceptional degree. The elevator will have a dedicated emergency generator so that disabled or injured building occupants can get to the roof to escape a tsunami after a major earthquake.
“In Oregon at least, this is the most comprehensive design that I have seen,” said OSU Dean of Engineering Scott Ashford.
He noted the new $50 million building was designed to remain standing even if the battering by a tsunami took out one of its concrete and steel support columns. Ashford chaired an oversight committee that reviewed the building plans.
Ashford said the deep cement mixing technique now observable at the Newport construction site is a commonly used mitigation strategy around the world where liquefaction presents a threat. Liquefaction is a technical term for when the solid ground turns to jello in an earthquake.
Only one other new building on the Pacific Northwest coast incorporates an engineered, elevated tsunami refuge. It’s on the roof of the Ocosta Elementary School gym in Westport, Washington.
This summer, the Shoalwater Bay Tribe on Washington’s Willapa Bay received a $2.2 million FEMA grant to design and build a tsunami evacuation tower for people on the vulnerable Tokeland peninsula. This could end up being the third engineered tsunami evacuation structure on the Northwest coast.
There was controversy in 2015 when OSU decided to locate its new marine science building in the tsunami zone on soft, sandy soil subject to liquefaction. The state geologist and other experts wrote to the university president at the time to urge OSU to build outside the tsunami zone. The university determined a location away from the rest of the HMSC campus would be impractical, which led to the current beefy building design.
The construction of these vertical evacuation structures does not change the standard advice from emergency managers for coastal residents and visitors to run to natural high ground if possible after the shaking from a major earthquake subsides. People who evacuate to a vertical platform may find themselves trapped and isolated by the surrounding destruction after a tsunami. However, that may be the best option available if natural high ground is too far away to reach quickly on foot.