How It Works
Benches are cut in lifts of typically 4-6 feet.
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.
Horizontal and vertical drain strips are installed onto the face to eliminate hydrostatic pressure and control seepage.
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.
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"