Logsden Road Slide Repair | Lincoln County, Oregon

Logsden Road Slide Repair | Lincoln County, Oregon

DESCRIPTION:  Unusually heavy rainfall in mid-January 2012 caused a series of landslides in Lincoln County, Oregon.  During that time, a section of unpaved roadway failed on Logsden Road at about MP 18.3.  The failure was apparently triggered by runoff from the road surface and a partially blocked culvert.  A large volume of soil, rock, trees and debris flowed down to an existing timber road.  The resulting near-vertical headwall closed Logsden Road, which provides access to county residents and local timber trucks.

SERVICE:  Foundation Engineering evaluated the failure and concluded a rock buttress would be the most practical, cost-efficient method to quickly repair the landslide and re‑open the road.  Working with the engineering team and a contractor selected by the County, Foundation Engineering developed guidelines in the field for keyway construction, fill slopes, and drainage.  The landslide was repaired within two weeks using ±8,800 tons of large riprap and jaw-run quarry rock.  Additional improvements included regrading the roadway, installing additional culverts, and repairing adjacent slopes that had been damaged by erosion.