PACIFIC NORTHWEST EDITION
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April 7 2024 Vol. VIII • No. 7
“The Nation’s Best Read Construction Newspaper… Founded in 1957.” Your Pacific Northwest Connection – Sharon Swanson – 1-760-518-4336 – sswanson@cegltd.com
Advanced Excavation Makes Repairs After Oregon Collapse By Lori Tobias CEG CORRESPONDENT
Four months after heavy Oregon rains washed out a coastal road, Sandlake Road is open to one lane and engineers are considering the best of two permanent repairs. A 175-ft. section of road connecting the destination town of Pacific City and residential village north of Tierra Del Mar slipped from the headlands the first week of December. “There was just a lot of ground saturation and the hillside just collapsed on itself,” said Chris Laity, Tillamook County public works director. “There was stack of soil and that was on top of sandstone, so it had a hard layer. As the water would seep its way down through the soil, it would hit sandstone. The water sliding across it caused a slip plane and that caused the road to fail.” While the road is not heavily traveled, it is the route residents in Tierra Del Mar take to do business in Pacific City, including picking up mail at the United States Post Office. While one lane remained intact, Laity and experts didn’t trust it to hold, so they barricaded off the existing lane. That meant a normally 10-min. drive from Tierra Del Mar to Pacific City suddenly became one of 45 minutes and that grew old fast. So, some took matters in their own hands. “People moved barricades,” Laity said. “They cut chains, cut the cables. It was a little bit of a fight on that one.” By February, Geostabilization International, headquartered in Colorado, moved in with specialized equipment to build a soil nail wall. Advanced Excavation, based out of Garibaldi, Ore., is serving as the general contractor. “You have rods that are drilled into the soil, about 30 feet in and they’re about one inch in diameter,” Laity said. “There’s about 200 of them and once they are drilled into the soil, there’s a thick welded wire mesh that goes over the top of the nails and then it’s basically a ginormous washer with a bolt that is screwed onto the nails. You’ve got the wire mesh and all the nails supporting the weight of the soil and then it's all shotcrete. They spray concrete on it and that seals
Advanced Excavation photo
Officials are contemplating the best solution after a 175-ft. section of road in Tillamook, Ore., connecting the destination town of Pacific City and residential village north of Tierra Del Mar, slipped from the headlands.
up everything from corrosion.” Now that one lane of Sandlake Road is open to traffic, Laity and county and state officials must decide on the best permanent repair. One option is the placement of a mechanically stabilized vertical wall, while the other is a slope. Both involve the layering of geogrid and soil and both are considered stable and good options, but there are differences, Laity said. see OREGON page 6
ODOT photo
One option is the placement of a mechanically stabilized vertical wall, while the other is a slope. Both involve the layering of geogrid and soil and both are considered stable and good options.