A major seismic event is predicted to hit the Oregon Coast any year now, which has transportation planning experts asking, “Is Oregon prepared?”

OTREC seismic expert and Portland State University Associate Professor of Civil and Environmental Engineering Peter Dusicka recently spoke at a May 13 symposium titled, Next Big Earthquake In Oregon: Are We Ready? Along with five other PSU professors, the Maseeh College-sponsored symposium addressed the state’s preparedness in terms of emergency response and infrastructure. Dusicka’s talk focused on the ability of Oregon’s bridges to perform in a major earthquake.

“We depend on our network of bridges for anything from immediate emergency response to transportation of goods and services,” Dusicka said. “There is no doubt that there is an inventory (of bridges) within Oregon of a certain vintage where we know there will be issues.”

The ability of a bridge to withstand a seismic event can depend on the type of bridge, when it was constructed and how it’s supported in terms of a foundation, Dusicka said. OTREC recently worked with ODOT to examine several hundred bridges in Oregon for seismic deficiency. The most telling trait, Dusicka said, is age.

“Over time, we’ve learned the ways we’ve designed and built bridges are not the best for resisting earthquakes,” Dusicka said. “The challenge with remediation today is, do we have the knowledge to do this effectively, and if we do, do we have the funds to execute solutions?”

Further complicating matters, Oregon’s type of earthquake will behave differently than well-studied and documented earthquakes in places like California. Because it will be a subduction zone event, the earthquake will last longer and effect a much larger area than a typical earthquake. The methods for retrofitting bridges to withstand this type of earthquake will also be different, Dusika said.

OTREC is currently funding an ODOT project to look at the vulnerability of a common bridge type in Oregon, the multi-column reinforced concrete bent bridge.  Though this bridge is frequently used in the state, there has been little research into how this bridge will perform in a seismic event. In the meantime, more funding is needed at the state level to implement bridge retrofits to guarantee a stable transportation system in the case of a major seismic event.

“ODOT does the best they can with the funds they have,” Dusicka said. “Whenever they have a project on a bridge, they perform a phase one retrofit. It's inadequate when you look at the scale of inventory and the scale of potential problems, but currently, there is no dedicated state funding to do seismic retrofits for bridges.”