Jim Imbrie was about to summit Mount Adams on May 18, 1980, the day the volcano Mount St. Helens blew its top.
He was 18 years old, and the event changed his life. He went on to become a geologist, then a geotechnical engineer, and later founded Tigard-based GeoPacific Engineering.
As he retells the story, however, he doesn't stress the upward blast that threw 540 million tons of ash into the sky. Nor even the sideways explosion that preceded it from the bulge on the side of the mountain. Imbrie was captivated by the landslide that happened seconds before all of that, as rock and mud swamped Spirit Lake.
He and his best friend and that friend's brother Bruce Poulin were climbing Adams when they watched what they thought was just another in a string of eruptions from St. Helens that had been going on for months. Bruce Poulin even managed to take six photos of it at the end of his roll of film. It was only when the electrical storm hit them that they retreated.
GeoPacific Engineering has been around for 20 years now and has 19 employees, six of whom are partners. It was born when the company he worked for, Adapt Engineering, was bought out. The new owners only wanted a portion of the firm in Seattle, so Imbrie was offered the chance to buy the remaining part and run it.
GeoPacific Engineering focuses on the area from Longview, Washington down to Eugene, and to the coast. The job is a bit like being a home inspector: you call one in before buying a house to assess its fair value. Just as you need to know if you are purchasing a fixer-upper, a developer needs to know the land is as stable as possible and won't be a costly nightmare.
A lot of Imbrie's work is testing the soil for suburban development, which can range from 10 to 200 homes.
"We're trying to identify all of the things wrong with the soils and geology," he told the Business Tribune. "A lot of our clients hire us before we even purchased the property. They want us to look at it and see what's wrong with it. So if we can identify those extra costs due to shallow groundwater, landslides, hard rock, liquefiable soils, expansive soils…"
With that data, the developer can determine what's a fair price to pay for the project, fix those problems, and safely build homes on it.
You might think the state would have all this geological data already, but they don't. Cities and counties keep it, to varying degrees.
"The City of Portland is meticulous record keeping, but some other cities or counties are not so meticulous," says Imbrie.
A lot of clients will take a current study and have GeoPacific redo it, just to be sure.
Work begins by taking a backhoe and digging pits 12 to 15 feet deep to analyze the soil. Sometimes they use a larger excavator if there are hard rock concerns and underground utilities. If there are "slope concerns," which means the potential of landslides, they use a drill rig and do deeper borings, down to 80 feet.
It's not just greenfield in suburbia: the company has tested the ground for many apartment buildings in the Portland area that are still being built.
He compares 2020 favorably to the Great Depression of 2009.
"This time, the residential market isn't saturated with an oversupply of homes, and they've lowered interest rates. It's actually going fairly strong right now. It seems counterintuitive, but we have a low inventory for new homes and existing homes."
The more challenging work for Imbre's company, he says, is assessing landslides. Builders need to know if they have to be avoided or remediated. Soil flows downhill, as does the rock beneath it, if it's loose.
"The more you know about them, the more you realize how difficult it is to predict. I'd say I knew more about landslides when I was 30 than I do now!"
Civil engineers are used to building roads across places with potential landslides. For example, a large part of the new Sellwood Bridge cost went to shoring up the land on the west end. But the houses are more critical. "People are more careful when they build buildings," says Imbrie.
Portland is covered by a thick layer of both catastrophic flood deposits and higher up in the hills, windblown silt, or loess deposits. "They're so thick they make it more difficult to see what's underlying them. The West Hills has a number of slides, and most of them are loess."
Often, the company measures soil compaction, making sure any soil being moved is adequately compacted.
When Imbrie and his pals were up Mount Adams, at 9,600 feet, they witnessed the updraft of the explosion pull in air from 360 degrees around the crater. This brought with it whole tree branches which caught fire in the air and then were deposited minutes later as fall out — right on top of the climbers. They were 35 miles away from Mount St. Helens.
"The landslide was mostly fractured rock and ice and probably a little water," he said of that formative earth movement. "It likely took a little time after the landslide for the glaciers to melt and send the lahar of ashen mud, trees, and rock down the Toutle River drainage."
Meanwhile, on Mount Adams, "We had gravel-sized pellets that were saturated in sulfuric acid raining out of the sky, along with flaming tree branches," he says.
As they scrambled down the mountain, the air was thick with ash. "The concentration of ash in the air caused electrical storms. There were orange and red lightning bolts that were striking the ground around us continuously." (People on airplanes confirmed these electrical storms.)
"The people who were on the mountain ahead of us said they had seen St. Elmo's fire on their ice axes."
They had been up since 1 a.m. and at 8 a.m. were still hoping to ascend Adams. Imbrie had no idea if they would live. "We blindly stumbled down the mountain in the dark. We had handkerchiefs over our mouths and noses."
Bruce Poulin had spent the night before, in the tent, telling them about the eruption of Vesuvius, which buried ancient Pompeii, so they all feared they might be going the same way. Imbrie put on ski goggles to make it back down to the lunch counter, a flat area where climbers camp before their ascent.
The electronic news media said that all 18 climbers on Mount Adams had been killed, and since there were no cell phones, Imbrie's parents thought he was dead until he let himself in at 11 o'clock that night.
Vocation, vocation, vocation
After high school, he studied engineering at Oregon State University, took a geology class, and was hooked.
Most technical staff have degrees in geology or engineering.
"We have a low turnover," Imbrie says.
It's also a hybrid white-collar, blue-collar job. "A lot of our technicians, even the degreed geologists, are learning in the field about geology before they graduate to doing office work." This means they have to put the hours in muddy fields before they can do more theoretical work.
On smaller projects, they sometimes work for structural engineers. On larger projects, maybe for the architects or also just directly for the owner.
"Portland lets the architect lead the project. I don't know why, but that's the way it is."
Another part of what they do is inspecting construction sites to ensure that when the foundation is being dug, the retaining walls and tiebacks are up to strength and are not likely to collapse on workers. Risk management is a key part of construction management.
"You could spend a whole lot of money and make something very safe. Or you could spend very little money and build something that's unsafe. But you have to find the happy medium. The big gray zone of geotechnical engineering and geology is trying to find that happy medium to make the city happy and the developer happy."
Construction was simpler in the 1980s, and Oregon was poorer. When he was looking for a job in 1984, there were only two or three geotechnical firms in Portland. Now there's 40 or 50.
Today as a manager, he prefers to focus on people as much as science.
"From my experience, businesses that are run by professionals, like geologists or engineers, are not very good businesses to work at. They don't treat their employees very well. They're thinking about calculations and they think, 'You should be just grateful that you're working for somebody as knowledgeable as me.'"
Imbrie is comfortable looking ahead.
"We're in a really good place right now. That's why I'm more optimistic than I probably have ever been, no matter what the economy does."
Reporter, The Business Tribune
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