The city of Murrieta, Calif., is famous for its Murrieta Diamond gem-shaped logo. The logo adorns street signs, city hall and—because of a 3-D erosion control system—the new interstate interchange just outside the town.
The city wanted the “Superman-like” gem crest to greet visitors from I-215 as they come into town. The logo and surrounding embankment are filled with decorative rock. The difficulty in using decorative stone is that it is subject to gravity and will slide down a slope. Murrieta and California Department of Transportation designers searched for a stabilizing solution and found Slopetame2 erosion control system. This system, manufactured by Invisible Structures, is a specialized erosion control geosynthetic with a combination geotextile fabric injection that is molded (not glued) to a 3-D ring-and-grid structure. It is manufactured in large, interconnecting rolls. The rolls are anchored to a hillside with a combination of rebar and specialized anchors.
Completed in June 2014, the main diamond shape was outlined in concrete, with Slopetame2 placed inside and outside of the logo. Different-colored decorative stone filled different areas of the embankment and the logo, creating the gem effect the city was looking for.
The system was chosen for its 1-in.-high structure and specific design that would prevent stone movement. The 1-in.-high fill meant less decorative stone than would be required for a 4-in.-high geocell, translating to savings on installation costs. Its integrated geotextile fabric meant that the decorative stone would not work its way below the structure, forcing the system to pop up. The fabric backing on Slopetame2 also added to the immediate erosion control protection of the embankment.