How It Works

Excavation:

Benches are cut in lifts of typically 4-6 feet.

Nails:

Holes are drilled into the excavated face. Each drill hole is filled with cement grout and a nail is inserted. The grout binds the nail to the surrounding soil and provides corrosion protection. A steel plate attached to the protruding end of each nail helps transfer forces from the wall to the nail and soil.

Drainage:

Horizontal and vertical drain strips are installed onto the face to eliminate hydrostatic pressure and control seepage.

Facing:

A facing, constructed from shotcrete reinforced by welded wire mesh or reinforcing bar mats, provides structural integrity.

The shotcrete can be smooth troweled for a finished appearance or sculptured for an architectural look to resemble the local geology.

Continuing Construction: After each lift is completed, excavation continues to the next bench and the process is repeated to completion.

Advantages of Soil Nailing:

• With the right soil and site conditions, a rapid and economical means of constructing earth retention support systems and retaining walls.
• Allows foundation construction in limited areas.
• Works through different soil strata.
• Constructed from the top down.
• Shorter drill holes.
• Smaller diameter bars at shorter lengths.
• Retaining walls are secured laterally into the soil, eliminating piles and foundation footers.
• Excavation for the building and wall construction can proceed simutaneously, saving schedule time.
• Not prestressed, saving labor costs and time.
• Grouting only once is required, saving time and labor.
• Requires only cohesive soil or broken rock, does not need to be anchored in competent rock.
• Drainage system included eliminates hydrostatic forces on facing.
• Hard face shotcrete is applied and can be finish-troweled.
• Forming and placing concrete wall not necessary, saving time, materials, labor.
• Soft facing can be applied for soil retention or slope protection.

Articles

Better Roads Publication - "Soil Nailing - DOTs Warm Up to New Technology"

Project: Omaha I-80 Realignment

Judy Company was the Soil Nail Wall subcontractor for this project

The Roadrunner Magazine - Nebraska Department of Roads - Page 5 Article "Aesthetic Wall Provides Impressive New Eastern Gateway into Nebraska"