Standard Test Method for Mechanical Cone Penetration Testing of Soils

Importancia y uso:

4.1 Tests performed using this test method provide a detailed record of cone resistance that is useful for evaluation of site stratigraphy, engineering properties, homogeneity and depth to firm layers, voids or cavities, and other discontinuities. The use of a friction sleeve can provide an estimate of soil classification, and correlations with engineering properties of soils. When properly performed at suitable sites, the test provides a rapid means for determining subsurface conditions.

4.2 This test method provides data used for estimating engineering properties of soil intended to help with the design and construction of earthworks, the foundations for structures, and the behavior of soils under static and dynamic loads.

4.3 This method tests the soil in-situ and soil samples are not obtained. The interpretation of the results from this test method provides estimates of the types of soil penetrated. Soil samples from parallel borings may be obtained for correlation purposes, but prior information or experience may preclude the need for borings.

4.4 Electronic cone data (D5778) is generally more reliable and reproducible. Mechanical cone equipment may prove useful when penetrating strong or rocky soils that might damage electronic cone equipment. Mechanical cone equipment typically requires less operator expertise to operate and to properly maintain than electronic cone equipment. However, mechanical cone equipment is not recommended for liquefaction investigations or investigations where a high level of quality assurance must be obtained.

4.4.1 There are many local and regional design guides based solely on mechanical CPT data for estimating engineering properties. It should be remembered, however, that mechanical cone data differ from electrical cones (D5778) because of the geometry of the cone and friction sleeve sections: large differences in R_f (which affects estimated soil type) and smaller differences in tip resistances. Users of these test data are cautioned that engineering property correlations for electronic cones are not to be used with data from mechanical cones.3

Note 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it and the suitability of the equipment and facility used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some, but not all, of those factors.

Subcomité:

D18.02

Referida por:

D5434-25, D5195-21, E2060-22, D5778-20, D6151-25

Volúmen:

04.08

Palabras clave:

cone penetration test; CPT; Dutch Cone; end bearing; field test; In-situ test; penetrometer; point resistance; site exploration; sleeve friction; soil investigation;