This test method will provide a relationship between time to failure, creep rate, and displacement to failure for specific failure loads at specific test temperatures as well as a relationship between creep rate and applied load at specific test temperatures for loads less than failure loads.

Pile design for specific soil temperatures may be controlled by either limiting long-term stress to below long-term strength or by limiting allowable settlement over the design life of the structure. It is the purpose of this test method to provide the basic information from which the limiting strength or long-term settlement may be evaluated by geotechnical engineers.

Data derived from pile tests at specific ground temperatures that differ from the design temperatures must be corrected to the design temperature by the use of data from additional pile tests, laboratory soil strength tests, or published correlations, if applicable, to provide a suitable means of correction.

For driven piles or grouted piles, failure will occur at the pile/soil interface. For slurried piles, failure can occur at either the pile/slurry interface or the slurry/soil interface, depending on the strength and deformation properties of the slurry material and the adfreeze bond strength. Location of the failure surface must be taken into account in the design of the test program and in the interpretation of the test results. Dynamic loads must be evaluated separately.

Note 3—The quality of the results produced by application of this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.

1.1 These test methods cover procedures for testing individual vertical piles to determine response of the pile to static compressive load applied axially to the pile. These test methods are applicable to all deep foundation units in permafrost that function in a manner similar to piles regardless of their method of installation. This standard is divided into the following sections: