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1.1 Purpose and Application:
1.1.1 This guide summarizes the equipment, field procedures, and
interpretation methods for the assessment of sub surface materials
using the impulse Ground Penetrating Radar (GPR) Method. GPR is
most often employed as a technique that uses high-frequency
electromagnetic (EM) waves (from 10 to 3000 MHz) to acquire
subsurface information. GPR detects changes in EM properties
(dielectric permittivity, conductivity, and magnetic permeability),
that in a geologic setting, are a function of soil and rock
material, water content, and bulk density. Data are normally
acquired using antennas placed on the ground surface or in
boreholes. The transmitting antenna radiates EM waves that
propagate in the subsurface and reflect from boundaries at which
there are EM property contrasts. The receiving GPR antenna records
the reflected waves over a selectable time range. The depths to the
reflecting interfaces are calculated from the arrival times in the
GPR data if the EM propagation velocity in the subsurface can be
estimated or measured.
1.1.2 GPR measurements as described in this guide are used in
geologic, engineering, hydrologic, and environmental applications.
The GPR method is used to map geologic conditions that include
depth to bedrock, depth to the water table (Wright et al (1)2 ),
depth and thickness of soil strata on land and under fresh water
bodies (Beres and Haeni (2)), and the location of subsurface
cavities and fractures in bedrock (Ulriksen (3) and Imse and Levine
(4)). Other applications include the location of objects such as
pipes, drums, tanks, cables, and boulders , mapping landfill and
trench boundaries (Benson et al (6)), mapping contaminants
(Cosgrave et al (7); Brewster and Annan (8); Daniels et al (9)),
conducting archaeological (Vaughan (10)) and forensic
investigations (Davenport et al (11)), inspection of brick,
masonry, and concrete structures, roads and railroad trackbed
studies (Ulriksen (3)), and highway bridge scour studies (Placzek
and Haeni (12)). Additional applications and case studies can be
found in the various Proceedings of the International Conferences
on Ground Penetrating Radar (Lucius et al (13); Hannien and Autio,
(14), Redman, (15); Sato, (16); Plumb (17)), various Proceedings of
the Symposium on the Application of Geophysics to Engineering and
Environmental Problems (Environmental and Engineering Geophysical
Society, 1988-1998), and The Ground Penetrating Radar Workshop
(Pilon (18)), EPA (19), and Daniels (20) provide overviews of the
GPR method.
1.2 Limitations:
1.2.1 This guide provides an overview of the impulse GPR method. It
does not address details of the theory, field procedures, or
interpretation of the data. References are included for that
purpose and are considered an essential part of this guide. It is
recommended that the user of the GPR method be familiar with the
relevant material within this guide and the references cited in the
text and with Guides D 420, D 5730, D 5753, D 6429, and D 6235.
1.2.2 This guide is limited to the commonly used approach to GPR
measurements from the ground surface. The method can be adapted for
a number of special uses on ice (Haeni et al (21); Wright et al
(22)), within or between boreholes (Lane et al (23); Lane et al
(24)), on water (Haeni (25)), and airborne (Arcone et al (25))
applications. A discussion of these other adaptations of GPR
measurements is not included in this guide.
1.2.3 The approaches suggested in this guide for using GPR are the
most commonly used, widely accepted, and proven; however, other
approaches or modifications to using GPR that are technically sound
may be substituted if technically justified and documented.
1.2.4 This guide offers an organized collection of information or a
series of options and does not recommend a specific course of
action. This document cannot replace education or experience and
should be used in conjunction with professional judgements. Not all
aspects of this guide 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 projects 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.
1.3 Precautions:
1.3.1 It is the responsibility of the user of this guide to follow
any precautions in the equipment manufacturer's recommendations and
to establish appropriate health and safety practices.
1.3.2 If this guide is used at sites with hazardous materials,
operations, or equipment, it is the responsibility of the user of
this guide to establish appropriate safety and health practices and
determine the applicability of any regulations prior to use.
1.3.3 This guide does not purport to address all of the safety
concerns that may be associated with the use of the GPR method. It
is the responsibility of the user of this guide to establish
appropriate safety and health practices and to determine the
applicability of regulations prior to use.
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