Значение и использование

This practice, or Practice D3550 with thin wall shoe, is used when it is necessary to obtain a relatively intact specimen suitable for laboratory tests of engineering properties or other tests that might be influenced by soil disturbance.

Note 2—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 facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective sampling. Users of this practice. 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.

TABLE 2 Suitable Thin-Walled Steel Sample Tubes^A

Outside diameter (D_o): in.
mm2
50.8 3
76.25
127 Wall thickness: Bwg181611 in.0.0490.0650.120 mm1.241.653.05 Tube length: in.
m36
0.91 36
0.9154
1.45 Inside clearance ratio, %<1 <1<1

^A The three diameters recommended in Table 2 are indicated for purposes of standardization, and are not intended to indicate that sampling tubes of intermediate or larger diameters are not acceptable. Lengths of tubes shown are illustrative. Proper lengths to be determined as suited to field conditions.

Область применения

1.1 This practice covers a procedure for using a thin-walled metal tube to recover relatively intact soil samples suitable for laboratory tests of engineering properties, such as strength, compressibility, permeability, and density. Thin-walled tubes used in piston, plug, or rotary-type samplers should comply with Section 6.3 of this practice which describes the thin-walled tubes.

Note 1—This practice does not apply to liners used within the samplers.

1.2 This Practice is limited to soils that can be penetrated by the thin-walled tube. This sampling method is not recommended for sampling soils containing gravel or larger size soil particles cemented or very hard soils. Other soil samplers may be used for sampling these soil types. Such samplers include driven split barrel samplers and soil coring devices (D1586, D3550, and D6151). For information on appropriate use of other soil samplers refer to D6169.

1.3 This practice is often used in conjunction with fluid rotary drilling (D1452, D5783) or hollow-stem augers (D6151). Subsurface geotechnical explorations should be reported in accordance with practice (D5434). This practice discusses some aspects of sample preservation after the sampling event. For information on preservation and transportation process of soil samples, consult Practice D4220. This practice does not address environmental sampling; consult D6169 and D6232 for information on sampling for environmental investigations.

1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.4.1 The tubing tolerances presented in Table 1 are from sources available in North America. Use of metric equivalent is acceptable as long as thickness and proportions are similar to those required in this standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

1.6 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process.

TABLE 1 Dimensional Tolerances for Thin-Walled Tubes

Nominal Tube Diameters from Table 2^A Tolerances Size Outside
Diameter2
in.50.8
mm3
in.76.2
mm5
in.127
mm Outside diameter, D_o+0.007 +0.179+0.010+0.254+0.0150.381 -0.000-0.000-0.000-0.000-0.000 -0.000 Inside diameter, D_i+0.000 +0.000+0.000+0.000+0.000+0.000 -0.007-0.179-0.010-0.254-0.015 -0.381 Wall thickness±0.007±0.179±0.010±0.254±0.015±0.381 Ovality 0.0150.3810.0200.5080.030 0.762 Straightness0.030/ft2.50/m0.030/ft 2.50/m0.030/ft2.50/m

^A Intermediate or larger diameters should be proportional. Specify only two of the first three tolerances; that is, D_o and D_i, or D_o and Wall thickness, or D_i and Wall thickness.