Soil nailing is used primarily for excavation support or slope stabilization. This process involves the installation of closely spaced soil nails drilled near horizontal and the application of a facing material such as reinforced shotcrete or structural mesh. The soil nails themselves tend to be small in diameter, typically 4″ to 6″, and consist of a center reinforcing bar surrounded by grout. Soil nail spacing usually ranges from 4′ to 6′ on center vertically and horizontally with the top row of soil nails generally being placed in the upper two feet of the excavation or slope.
From a design standpoint, soil nailing is a passive system attempting to place enough anchorage into the adjacent soil so it acts as a “reinforced block” to resist overturning. The load demand on each nail tends to be fairly low as they are intended to act as a group. In the case of excavation support, the facing is usually designed to take little load but more so tie the system together. In the case of slope stabilization, the facing may be designed to take more load and the nails may be post tensioned.
•Soil nailing is generally faster and more cost effective than other excavation support methods.
•Nail locations can easily be adjusted in the field if obstructions are encountered.
•Soil nailing can be designed for temporary or permanent applications.
•Shotcrete facing can be carved and stained to provide decorative finish options.
•Soil nailing can be installed with relatively small equipment
•Soil nailing is not well suited for applications below the ground water table
•Soil nails may require permanent underground easements
•Adjacent underground utilities can be a problem
•Soil nail walls are less rigid than other methods and therefore may require underpinning of adjacent structures
•Temporary excavation support
•Permanent excavation support
This technique is available through Axiom Foundations. Contact us for more information on soil nailing!