The landslides included shallow slipouts, deep-seated landslides and shallow block failures. Landslide geometries range from 30 to 270 feet in length and 50 to 140 feet in width. Failures occurred both above and below the roadway prism.

Shannon & Wilson is responsible for geotechnical explorations, laboratory testing and providing conceptual preliminary designs and subsequent final designs for landslide repair. We also researched and presented a CalRecycle grant opportunity for additional funding to use a lightweight tire-derived aggregate for soldier pile wall backfill and reconstructed embankments.

We are completing soldier pile wall and embankment design and collaborating with CalRecycle on preliminary engineering for the tire-derived aggregate lightweight fill. Some landslides will use lightweight backfill embankment reconstruction to reduce driving forces where remediation of the landslide is not economically feasible. Drainage improvements will include trench drains, horizontal drains, and improved surface drainage.