The use of soil nails works best in soils that are sandy but with sufficient clay to allow unsupported cuts of up to 7 feet to stand temporarily. This system is not advisable to use next to buildings. Their strength is derived from the fact that the wall displaces slightly and the steel tendons stress and induce increased shear strength to the soil.
The soil nails are typically closely spaced and a 4″ thick shotcrete facing is applied to the earth face after the nails are drilled. One of the advantages of soil nails is that only a small percentage (5-10%) of the nails are tested which reduces the cycle time between rows. This method can result in cost-effective top-down construction.