Soil nails are drilled and grouted bars (normally threaded steel bar or reinforcement, but may be fibreglass). Installed on a regular grid pattern the nails are passive (non-stressed) elements and typically secure a facing support of shotcrete and/or mesh with a nut and plate or cogged end.

Soil nail walls are particularly well suited to excavation applications for ground conditions that require vertical or near-vertical cuts, and have been proven to be ideal for the following temporary and permanent applications:

• Road & rail cuttings.
• Road & rail widenings beneath existing bridges.
• Access for loading docks into warehouse/retail on sloping sites.
• Repair and reconstruction of existing retaining structures.
• Temporary or permanent excavations in urban environments.

As a general rule of thumb, soil nailing is economically attractive and technically viable when:

• The excavated soil batter can stand unsupported at vertical or near vertical to a height of 1-2m for one to two days.
• All soil nails within cross section are above groundwater table.