ASTM D4428/D4428M : 25

1.1 These test methods are limited to the determination of the low strain (<10^–4 %) velocity of two types of horizontally travelling seismic waves in soil materials; primary compression (P-wave) and secondary shear (S-wave) waves. The standard assumes that the method used to analyze the data obtained is based on first arrival times or interval arrival times over a measured distance.

1.2 Various applications of the data are addressed and interpretation procedures and equipment, such as seismic sources, receivers, and recording systems are discussed. Other items addressed include borehole spacing, drilling, casing, grouting, deviation surveys, and actual test procedures.

1.3 These test methods are primarily concerned with the actual test procedure, data interpretation, and specifications for equipment which will yield uniform test results. Data reduction and interpretation are limited to the identification of various seismic wave types, example computations, use of Snell's law of refraction, and assumptions.

1.4 There are several devices that can be used to generate high-quality P-waves or vertically polarized S-waves (SV-waves) or both and horizontally polarized S-waves (SH-waves). Several types of commercially available receivers and recording systems can also be used to conduct a crosshole survey.

1.5 All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026.

1.6 Units—The values stated in either SI units or inch-pound units [given in brackets] are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method.

1.7 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.