SR 530 Emergency Reconstruction Project Earns ACEC 2015 Engineering Excellence Award

ARLINGTON, Wash. - Atkinson, along with project design team members, Jacobs Engineering Group Inc., GeoEngineers, Inc., and Site Development Associates have earned the 2015 Engineering Excellence Honor Award for the successful completion of the SR 530 Emergency Roadway Reconstruction project.

The Oso landslide destroyed dozens of homes, and spread 10 million cubic yards of mud, trees, and debris over a half-mile area in the Stillaguamish River Valley. It also demolished a one-mile section of Washington State Route 530, leaving a string of rural Cascade Mountain foothill communities isolated and economically paralyzed for four months. 

During the design phase, Atkinson worked closely alongside the design team to develop unique geotechnical engineering solutions. The team's efforts proved successful, and the roadway reopened a few short months after the deadliest landslide in U.S. history.

The project team incorporated geotechnical innovations, including horizontal slope drains and slope stabilization. These tactics allowed portions of the new roadway to be constructed over the soft, unstable landslide deposits. Crews also raised the road profile as much as 20 feet in elevation to account for the new flood plain.

The road was completed with unprecedented speed, opening just 13 weeks after construction began, and exactly six months to the day of the Oso landslide.