The objective of the study was to provide alternatives called soil bioengineering methods for slope and shallow rapid landslide stabilization along different roadside environments. Additional objectives were to educate WSDOT personnel in site selection, soil bioengineering techniques, and construction; to provide soil bioengineering decision-making skills.
Three study sites were selected: based upon the following criteria: safety, visibility, accessibility, representation of disparate moisture conditions, climate, and erosion types, illustration of different techniques, availability of additional funding, and WSDOT input. Three different combinations of soil bioengineering techniques were used to stabilize upland slopes on the roadside.
Results indicate soil bioengineering is an effective means of upland slope stabilization on erosional slopes and shallow rapid landslides and is practical and economical. Composted biosolids improved soil workability and enhanced the native plant community during the first year.
Source: Washington State Department of Transportation
Authors: Lisa Lewis | Sandra L. Salisbur | Shannon Hagen