On a roadside in Greendale, Wis., GEOWEB 3D geocells were integrated along a half-mile section of roadway designed to support the weight of rolling vehicles that might venture off onto the shoulder. R.A. Smith National, Inc.—the village of Greendale’s engineer—was tasked with designing a stabilized green roadway along the asphalt pavement that could safely support water loading, yet offer infiltration of highway runoff. Past problems included cars coming off the edge of the pavement and causing severe rutting.
Performance and stormwater benefits provided by 3D geocells compared to traditional crushed aggregate shoulder stabilization:
- Erosion and rutting in wet soil areas eliminated through strengthening of permeable fill confined in the system’s 3D structure.
- Sheet flow runoff infiltrates immediately at the point of contact to mitigate ponding and flooding issues.
- Stormwater quality improved through filtering of contaminants.
- Sealed pavements protected from deterioration and edge breaks.
A reduction in maintenance when compared to the many problems the village had experienced with maintaining aggregate shoulders in this area was an additional benefit.
Six-inch-deep GEOWEB sections fabricated 6 ft wide were expanded on both sides of the roadway to create ‘structural road shoulders’ to eliminate low and soft shoulder problems. The correct mixture of 65%, ¾-in. limestone chip stone and 35% topsoil was mixed and then placed into the GEOWEB sections. Werner Brothers Inc. of Ixonia, Wis., performed the shoulder work as a subcontractor to Black Diamond Group of Oak Creek, Wis.
After infilling the GEOWEB sections, an extra 2 in. of topsoil overfill was added for sustaining grass growth. With this plan, if a vehicle drives off the roadway, the wheels could only rut the upper 2 in. of unprotected topsoil. The 2-foot asphalt shoulder and 6-foot vegetated shoulder created an 8-foot shoulder that allowed any type of vehicle to leave the pavement without sinking. Once fully vegetated, the GEOWEB protection system is not visible, and the turf is stable years after placement.
Editor's Note: Scranton Gillette Communications and the SGC Infrastructure Group are not liable for the accuracy, efficacy and validity of the claims made in this piece. The views expressed in this content do not reflect the position of the Roads & Bridges' Editorial Team.
