Quick action was required to prevent an imminent release of refuse to the marine environment from a landfill perched atop a rapidly eroding high coastal bluff above the Straits of Juan de Fuca. We met the challenges posed by the site’s complex geometry with design elements including: aggressively steep cut and fill slopes (2.5H:1V) in refuse and a 110-foot-high mechanically reinforced earth buttress to stabilize the seismically unstable slope, a new cover system with a bentonite-amended low-permeability soil layer below a synthetic turf cap, and shoreline stabilization seawalls and revetments. Successfully accelerated, the project was completed in about half the time typical of similar projects.
For more than a decade, Aspect has provided ongoing geotechnical engineering and construction services for the landslide-damaged Rockaway Beach Road site. Aspect’s local knowledge of the geology and on-going erosion processes provided the basis for the development of the roadway repair. The repair included a shoreline revetment wall, mechanically reinforced earth slope, and re-built roadway shoulder. Aspect provided expedited support and recommendations for design changes that occurred late in the project and responsive field support during construction.