As soil nail construction requires temporary stability in both the staged excavation and also the drilled hole stability, any soils with sufficient temporary self-support of about 2m sub-vertical height for minimum of 1 to 2 days and hole stability for minimum four hours are considered suitable ground for soil nailing. With the above criteria, the following soil types would be suitable for soil nailing:

i. Stiff fine/cohesive soils

ii. Cemented granular soils

iii. Well graded granular soils with sufficient apparent cohesion of minimum 5kPa as maintained by capillary suction with appropriate moisture content

iv. Most residual soils and weathered rock mass without adverse geological settings (such as weak day-lighting discontinuities, highly fractured rock mass, etc) exposed during the staged excavation

v. Ground profile above groundwater level

Soil nailing can still be considered suitable for certain soil types or ground conditions if proper drilling equipment and flushing agent are carefully selected.

The major impacts to soil nailing works in the unsuitable ground conditions are mostly :

i. Loss of grout though the fractured rock mass, open joints and cavities

ii. Collapse of drilled-hole

iii. Poor nail-to-soil interface resistance due to disturbance of drilled-hole

iv. Localized face stability