Pinnacle Retaining Wall and Erosion Control Systems

Tensar Sierra^® Slope Retention System


n		MSE Segmental Retaining Walls (SRW)
n		MSE Berm
n		MSE Panel Walls
n		Vegetated MSE Slopes
n		Stone Faced MSE Walls
n		MSE Pressure Relief Walls
n		Cast-In-Place (CIP) Concrete Walls
n		Gravity Retaining Walls
n		Soil Nail Walls
n		Piling Walls
n		Gabion Structures
n		Above and Underground Stormwater Detention Structures
n		Composite Wall Systems
n		MSE Green Retaining Walls
n		Retaining Wall Repair

Wal-Mart's decision to enlarge its Walker Springs/I-40 store in Knoxville, Tennessee to a Wal-Mart Supercenter presented contractors with construction challenges and a civic opportunity.

The retailer's plans called for doubling the building's square footage and expanding the parking lot by building out from the back of the store. The parking lot expansion required construction of a 45-ft. retaining wall fronting protected wetlands-a series of forested springs designated to include the 10-Mile Creek Greenway, part of the nature/biking trail system linking west Knoxville to downtown.

Good-bye Gabions

"A gabion wall was originally specified, but we knew we could expedite construction and provide a more cost-effective and attractive value-engineered solution with the Sierra^® Slope Retention System," commented Joe Harris, President of Pinnacle Design/Build.

The Sierra System from Tensar Earth Technologies (TET) is a mechanically stabilized earth (MSE) retention system with a number of advantages over conventional retaining walls. A veteran of thousands of projects, the Sierra System can save up to 60% over concrete walls; installs quickly and easily without specialized equipment or labor; and is free from the cracking, leaning, bulging, and defacing that concrete walls typically endure. It also supports a number of facing options-from erosion blankets to natural vegetation to available fill.

Pinnacle and its project partner, J. Hicks Excavating of Kingston, Tennessee, and Superior Drainage Products of Knoxville, Tennessee, presented their Sierra System proposal to Site, Inc., civil engineers for all site construction excluding the building, as well as the Knox County Parks and Recreation Department. Following approvals, Hicks Excavating prepared the site foundation with layers of shot rock and graded crushed stone over bedrock.

The installed Sierra System features a tiered network of welded-wire baskets with granular crushed stone backfill (the available fill, a silty, high-plastic clay, was insufficient, according to Randy Neuhaus of S&ME, a geotechnical consulting firm). Tensar uniaxial (UX) and biaxial (BX) geogrids, key components of many TET engineered solutions, provide the soil reinforcement. The three-month construction took place from February through April of this year.

And the county's reaction to this sloping retaining wall? David Robinette, President of Site, Inc., described it as "ecstatic."

"It's a beautiful piece of construction-and pretty dramatic," commented Susan Kerr, Knox County Parks and Greenway Coordinator. "My main concerns were preservation and aesthetics-we had six springs and wetlands with mature trees to protect in the area. It's probably the best job I've ever seen building right up to the edge of a wetlands without disturbing anything-a 'win-win' for all of us."

Source: Tensar Corporation - Sierra Slope Retention System: A "Win-Win" Solution for Knoxville Wetlands and Wal-Mart

Tensar Sierra® Slope Retention System

Tensar Sierra^® Slope Retention System