Used automobile tires were recycled for a retaining wall to stabilize the slope below Gibraltar Road in the mountains above Santa Barbara.
Heavy rainfall during January 2005 saturated a cliff below the road, washing out the soil and removing part of the surface. The $90,000 project was constructed in two weeks during October 2008. The tire-anchor wall contains 280 tires of various sizes, arranged in 14 vertical layers. Sand backfill was placed between each row of tires to fill any air voids. Each tire is tied to the next with polypropylene rope.
After a wildfire singed the wall in 2011, the contractor returned in October of that year to apply a wire mesh and shotcrete for protection against damage from future fires.
Key Players
Owner: County of Santa Barbara, Dept. of Public Works, Santa Barbara
Contractor: Tierra Contracting, Santa Barbara
Lead Design: County of Santa Barbara
Highway and Street Construction: Nye & Nelson Construction, Ventura
Drill Rig: Javier’s Construction, Oxnard
Submitted by County of Santa Barbara, Dept. of Public Works
