Winter storms in late 2005 and early 2006 resulted in an embankment slide along Lakeshore Drive just north of San Joaquin Avenue. The embankment slide resulted in the loss of the paved shoulder in the outboard edge of the roadway.
Coastland completed design services for the City of Clearlake to repair the landslide. The federally funded Emergency Restoration (ER) project included widening the inside northbound lane by cutting into the existing embankment to create a uniform curve approximately 475 feet in length. The widening also included providing a drainage ditch along the uphill side of the road and an AC berm along the downhill side of the road to reduce surface water from migrating onto the downhill slope embankment.
To further reduce the potential for future slipping of the roadway, launched soil nails were used to reinforce the slope. The installation of the launched soil nails incorporated a reinforced shotcrete cap and were inserted into existing soil masses by high-pressure air.
In addition to design services, Coastland provided bid support and construction design support services. The project also required extensive coordination with Caltrans to meet funding requirements.