ASTM D5777-00(2006)
(Guide)Standard Guide for Using the Seismic Refraction Method for Subsurface Investigation
Standard Guide for Using the Seismic Refraction Method for Subsurface Investigation
SIGNIFICANCE AND USE
Concepts:
This guide summarizes the equipment, field procedures, and interpretation methods used for the determination of the depth, thickness and the seismic velocity of subsurface soil and rock or engineered materials, using the seismic refraction method.
Measurement of subsurface conditions by the seismic refraction method requires a seismic energy source, trigger cable (or radio link), geophones, geophone cable, and a seismograph (see Fig. 1).
The geophone(s) and the seismic source must be placed in firm contact with the soil or rock. The geophones are usually located in a line, sometimes referred to as a geophone spread. The seismic source may be a sledge hammer, a mechanical device that strikes the ground, or some other type of impulse source. Explosives are used for deeper refractors or special conditions that require greater energy. Geophones convert the ground vibrations into an electrical signal. This electrical signal is recorded and processed by the seismograph. The travel time of the seismic wave (from the source to the geophone) is determined from the seismic wave form. Fig. 2 shows a seismograph record using a single geophone. Fig. 3 shows a seismograph record using twelve geophones.
The seismic energy source generates elastic waves that travel through the soil or rock from the source. When the seismic wave reaches the interface between two materials of different seismic velocities, the waves are refracted according to Snell's Law (4, 8). When the angle of incidence equals the critical angle at the interface, the refracted wave moves along the interface between two materials, transmitting energy back to the surface (Fig. 1). This interface is referred to as a refractor.
A number of elastic waves are produced by a seismic energy source. Because the compressional P-wave has the highest seismic velocity, it is the first wave to arrive at each geophone (see Fig. 2 and Fig. 3).
The P-wave velocity Vp is dependent upon the bulk modulus, the sh...
SCOPE
1.1 Purpose and Application—This guide covers the equipment, field procedures, and interpretation methods for the assessment of subsurface conditions using the seismic refraction method. Seismic refraction measurements as described in this guide are applicable in mapping subsurface conditions for various uses including geologic, geotechnical, hydrologic, environmental (1), mineral exploration, petroleum exploration, and archaeological investigations. The seismic refraction method is used to map geologic conditions including depth to bedrock, or to water table, stratigraphy, lithology, structure, and fractures or all of these. The calculated seismic wave velocity is related to mechanical material properties. Therefore, characterization of the material (type of rock, degree of weathering, and rippability) is made on the basis of seismic velocity and other geologic information.
1.2 Limitations:
1.2.1 This guide provides an overview of the seismic refraction method using compressional (P) waves. It does not address the details of the seismic refraction theory, field procedures, or interpretation of the data. Numerous references are included for that purpose and are considered an essential part of this guide. It is recommended that the user of the seismic refraction method be familiar with the relevant material in this guide and the references cited in the text and with appropriate ASTM standards cited in 2.1.
1.2.2 This guide is limited to the commonly used approach to seismic refraction measurements made on land. The seismic refraction method can be adapted for a number of special uses, on land, within a borehole and on water. However, a discussion of these other adaptations of seismic refraction measurements is not included in this guide.
1.2.3 There are certain cases in which shear waves need to be measured to satisfy project requirements. The measurement of seismic shear waves is a subset of seismic refraction. ...
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D5777 – 00 (Reapproved 2006)
Standard Guide for
Using the Seismic Refraction Method for Subsurface
1
Investigation
This standard is issued under the fixed designation D5777; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope of these other adaptations of seismic refraction measurements
is not included in this guide.
1.1 Purpose and Application—This guide covers the equip-
1.2.3 There are certain cases in which shear waves need to
ment, field procedures, and interpretation methods for the
be measured to satisfy project requirements. The measurement
assessment of subsurface conditions using the seismic refrac-
of seismic shear waves is a subset of seismic refraction. This
tion method. Seismic refraction measurements as described in
guide is not intended to include this topic and focuses only on
this guide are applicable in mapping subsurface conditions for
P wave measurements.
various uses including geologic, geotechnical, hydrologic,
1.2.4 Theapproachessuggestedinthisguidefortheseismic
environmental (1), mineral exploration, petroleum exploration,
refraction method are commonly used, widely accepted, and
and archaeological investigations. The seismic refraction
proven; however, other approaches or modifications to the
method is used to map geologic conditions including depth to
seismic refraction method that are technically sound may be
bedrock, or to water table, stratigraphy, lithology, structure,
substituted.
and fractures or all of these. The calculated seismic wave
1.2.5 Technical limitations and interferences of the seismic
velocityisrelatedtomechanicalmaterialproperties.Therefore,
refraction method are discussed in D420, D653, D2845,
characterization of the material (type of rock, degree of
D4428/D4428M, D5088, D5730, D5753, D6235, and D6429.
weathering, and rippability) is made on the basis of seismic
1.3 Precautions:
velocity and other geologic information.
1.3.1 It is the responsibility of the user of this guide to
1.2 Limitations:
follow any precautions within the equipment manufacturer’s
1.2.1 This guide provides an overview of the seismic
recommendations, establish appropriate health and safety prac-
refraction method using compressional (P) waves. It does not
tices, and consider the safety and regulatory implications when
address the details of the seismic refraction theory, field
explosives are used.
procedures, or interpretation of the data. Numerous references
1.3.2 If the method is applied at sites with hazardous
are included for that purpose and are considered an essential
materials, operations, or equipment, it is the responsibility of
part of this guide. It is recommended that the user of the
the user of this guide to establish appropriate safety and health
seismic refraction method be familiar with the relevant mate-
practices and determine the applicability of any regulations
rial in this guide and the references cited in the text and with
prior to use.
appropriate ASTM standards cited in 2.1.
1.4 This standard does not purport to address all of the
1.2.2 This guide is limited to the commonly used approach
safety concerns, if any, associated with its use. It is the
to seismic refraction measurements made on land. The seismic
responsibility of the user of this standard to establish appro-
refraction method can be adapted for a number of special uses,
priate safety and health practices and determine the applica-
onland,withinaboreholeandonwater.However,adiscussion
bility of regulatory limitations prior to use.
1.5 This guide offers an organized collection of information
1
or a series of options and does not recommend a specific
ThisguideisunderthejurisdictionofASTMCommitteeD18onSoilandRock
and is the direct responsibility of Subcommittee D18.01 on Surface and Subsurface
course of action. This document cannot replace education or
Characterization.
experienceandshouldbeusedinconjunctionwithprofessional
Current edition approved July 1, 2006. Published August 2006. Originally
judgment. Not all aspects of this guide may be applicable in all
approved in 1995. Last previous edition approved in 2000 as D5777 – 00. DOI:
10.1520/D5777-00R06. circumstances. This guide is not intended to represent or
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D5777 – 00 (2006)
FIG. 1 Field Layout of a Twelve-Channel Seismograph Showing the Path of Direct and Refracted Seismic Waves in a Two-Layer Soil/
Rock System (a = Critical Angle)
c
replace the standard of
...
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