In The Mix, 2nd Edition

Volume 2 | November 2020

Leveling Landslides: Rescues & Resilient Repairs CNCA is in the business of helping solve some of California and Nevada's most pressing infrastructure challenges. While never visible at the end of these projects, a variety of cement solutions have a strong track record of stabilizing slopes in danger of collapse and in repairing mudslides to create resiliency against future challenges.

Rescuing a Canyon Hillside in Laguna Beach

In the 15 years since this dramatic landslide, recovery was made possible through the innovative use of soil cement shear keys and other geotechnical improvements.

Deep Assurance in Dramatic Rebuild Nathan Forrest, CNCA Technical Director

In the early morning hours of June 1st, 2005, residents of Bluebird Canyon in Laguna Beach awoke to a bang as an electrical transformer exploded and cut off power to the area. What happened next must have felt surreal; over the next several hours, the earth slowly slid downward moving approximately 50 feet vertically and 100 feet laterally, destroying 17 homes and seriously damaging 11 more.

For some longtime residents, this must have been a familiar feeling – a landslide in the same area in 1978 destroyed or damaged over 50 homes. In the aftermath, it was determined that the 2005 landslide had most likely been caused by unusually heavy winter rains, just as the 1978 landslide had been.

The ground had been saturated for many months following those rains and, for unknown reasons on that day, exceeded its limit of stability causing the earth to slide.

The extensive repair and recovery of this slide featured two soil-cement shear keys in conjunction with a series of cassion/tieback wall systems, surface and subdrain system, underground utilties and new roads.

Reopening in late 2007, Bluebird Canyon property owners began the process of rebuilding on reestablished lots. While not all landslides are this dramatic, these steps can be used to ensure resiliency in future developments and

infrastructure projects.

Contact CNCA's Nathan Forrest

Rescuing a Roadway - Faster, Lighter, Stronger

Lightweight Cellular Concrete is placed in a mudslide repair to provide the strength to raise the grade, pave the road, and quickly open to traffic.

After the Slides: Reinforcing Essential Roads Tyler Bodnar, CNCA Director of Geotechnical Markets

The scenic west coast road network can provide some of the most beautiful driving views in the country. Our roads wind and bend along the ocean front, inland waterways, and take you through the forest and into the thin air of the mountain regions. It is our precious infrastructure that allows us to have access to and enjoy these places. Every year, portions of these roads are affected by the geology that surrounds us as embankments slip and landslides expose the volatility of our built environment.

We have long worked to support resilient infrastructure that can withstand the elements. This effort also includes a focus on how we quickly re-build the

roads that get us to our destination. Numerous examples have shown how lightweight cellular concrete (LCC) can help expedite the reconstruction of lost embankments and slope repairs. A low-density, flowable, self-compacting material is ideal for rapidly raising grade and bringing our roads back to function. Designers, local agencies, and Caltrans have embraced LCC for use as embankment fill and all recognize the many benefits it provides.

Contact CNCA's Tyler Bodnar

Contact CNCA'sClay Slocum

Click To Learn More About LCC