How a hospital withstood a 9.0 quake with nary a broken window
This story is part of an Oregon Public Broadcasting series on how well the Northwest is prepared for the magnitude 9.0 earthquake that scientists say will hit along the Cascadia Subduction Zone just off the Pacific Coast.
In this report, OPB's Ed Jahn follows Jay Wilson of the of the Oregon Seismic Safety Policy Advisory Commission, paleo-seismologist with Oregon State University Chris Goldfinger and geotechnical engineer Allison Pyrch to learn how a hospital withstood a magnitude 9.0 quake with nary a broken window. Read the full series: Unprepared: Will We Be Ready for the Megaquake?.
Vans deliver a stream of patients to the front door of the Ishinomaki Red Cross Hospital. The five-story, 402-bed hospital functions today just as it did before, during and immediately after the 2011 earthquake and subsequent tsunami that struck the east coast of Japan.
The massive building rises like a beacon on a short incline in Ishinomaki City, several miles from Kadonowaki, which was severely affected by the tsunami; homes and businesses were reduced to rubble. The hospital was constructed in 2006 to replace another that used to be located along the waterfront. Experts concluded that the old hospital was vulnerable to a tsunami, so they closed it.
When the tsunami struck, a wall of water and debris destroyed nearly 46 percent of Ishinomaki City. The old hospital, which had been converted to a nursing school, was inundated to the ceiling of the first floor.
Dr. Iwao Kaneda works at the new hospital. He's busy today, with a lobby full of patients. Many are still undergoing treatment for lingering psychological trauma from the earthquake that killed more than 3,000 in the Ishinomaki area alone.
Dr. Kaneda makes it clear to Wilson that he only has time to talk for the 30 minutes he's allotted in his schedule. But the doctor — who was on duty at the hospital on the day of the earthquake — is eager to tell Wilson a success story from the tragedy.
On March 11, 2011 the hospital shook hard for about three minutes. Video from that day shows staff bracing against desks as doors swing back and forth and windows rattle uneasily.
"No staff were hurt and none of the important medical equipment was damaged," said Dr. Kaneda. No broken windows. No collapsed ceilings. No flooding from the tsunami that stopped miles from the hospital's doors.
The hospital wasn't wrapped in a magic bubble — its emergency water supply proved inadequate and its emergency generators provided only half the electricity staffers were accustomed to. But within an hour, the intact building was accepting patients and acting as a refuge for throngs of survivors who'd lost everything.
The Ishinomaki Red Cross hospital treated nearly 4,000 patients within the first seven days after the disaster. Normally, the hospital treats about 60 patients a day.
"If you are expecting the same kind of tsunami disaster we experienced, you have to build medical facilities in the areas the tsunami can't reach," Dr. Kaneda said.
He added that the building was engineered with large earthquakes in mind, then asked, "Have you seen our basement?"
Engineering Is the Key
Hiraku Abe, an engineer with Ishinomaki Red Cross, leads Jay Wilson of the of the Oregon Seismic Safety Policy Advisory Commission, paleo-seismologist Chris Goldfinger and geotechnical engineer Allison Pyrch down the stairs to the basement. It surrounds the building like a moat. The building floats above the basement on spring-like structures, made of rubber and steel. It's as if the building is balancing on over a hundred massive pogo sticks.
Prych gasps. "This is geotechnical engineering…" Pyrch hesitates before going for the word, "Porn!"
It's a feat of engineering called base isolation. After a series of technical exchanges with Abe, Prych explains that the system provides shock absorbers that cushion the five-story hospital above.
"The ground motions actually don't reach the structure. The building has a much calmer movement," Pyrch said. Pyrch is captivated by the design. This is not the way hospitals are built in Oregon.
Next, Abe shows Pyrch a large metal stylus suspended from the ceiling that reaches down to a metal plate bolted to the basement floor. During the earthquake, the stylus skipped and bounced, marking the plate like an Etch-A-Sketch.
"It bounced horizontally 26 centimeters and the other side also moved about the same distance," Abe said.
The stylus rendered in graphic form the ease with which the hospital weathered a 9.0 earthquake that ripped apart the surrounding countryside. The hospital rocked and rolled, then settled back into place. Engineers estimate the hospital can sustain several more earthquakes of equal magnitude without needing to replace the base isolation "springs."
Oregon's Earthquake Standards Far Weaker than Japan's
Pyrch, a member of an American Society of Civil Engineers group that examines seismic engineering throughout the world, says there's nothing like the Ishinomaki Red Cross hospital in Oregon.
That's because current state seismic standards only require new buildings to be safe enough for occupants to escape after an earthquake.
Japan's long history with earthquakes has created a different culture. "They design to make sure that the infrastructure is useable afterwards" Pyrch said.
In Oregon, even so-called seismically engineered buildings may have to be torn down if they sustain even one earthquake as large as the one that shook Ishinomaki.
"When I drive through Japan and I see all the bridges and overpasses I'm like, 'Wow, base isolation! Base isolation!' " Pyrch said. "I see something that's up and running and standing. And that's not the case when you drive through Oregon."
Chris Goldfinger, the paleo-seismologist, has absorbed this engineering show-and-tell in his own quiet way. He's used to talking in terms of great tectonic plates. He beats the drum of preparedness in Oregon because he knows the underlying science tells us we're due for a big quake.
He was in Japan during the 2011 earthquake and knows what it's like to be caught in a building as it shakes for what he says were four long minutes. But in the basement of the Ishinomaki Red Cross Hospital he is surrounded by humankind's answer to that natural phenomenon.
"I work on earthquakes in my office … and it's a bit abstract. But here in Japan it's not abstract. You see exactly how the earth interacts with people and that's where it departs from the science and becomes a societal issue," Goldfinger said.
To Chris Goldfinger, the science is in. Why wouldn't Oregon build like this?
How prepared is Oregon for a magnitude 9.0 quake? Read the full story: Japan Earthquake Holds Lessons For Oregon Coast
Listen to the report:
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And view the rest of the series, Unprepared: Will We Be Ready For The Megaquake?