Soil Nail Testing

Soil nail testing is performed to establish the bond stress within the stable zone of a slope. Typically, no more than 5% of the nails are selected for testing. Nails are incrementally loaded during testing.

Tests performed can include:

• Ultimate tests (sacrificial) where nails are tested until failure occurs.
• Proof tests can be performed on sacrificial or production nails.
• Creep tests are generally conducted during proof or sacrificial testing. Acceptance criteria should be based on allowable movements of the wall over its life span.
• Since hollow bar nails are fully grouted, it is necessary to establish the influence of the wedge zone bond on the total load. This will determine a more accurate assessment of the test load in relation to bond length.
• Test load is measured with a pressure gauge incorporated in the hydraulic jacking system. Nail movement is recorded by a dial gauge mounted on an independent stand.