May/June 2023 - 89

results, and the ways geophysical data
can be better presented to be more
easily incorporated into the geotechnical
baseline and data reports.
To that end, the group has underCollecting
data from an electrical resistivity survey (credit: J.W. Ramp Photography)
last 5 years at Delft University of
Technology in the Netherlands. This last
topic was suggested during the group's
last meeting in 2022, which focused on
what the group can do better and should
focus on in the year to come.
One of the objectives of the group is
to encourage the use of the design
methods that apply CPT data as direct
design inputs. While this design
methodology is widely applied abroad,
here in the U.S. its use is still very
limited, albeit that certain DOTs have
now issued design manuals that
describe this approach.
Another group activity is the
development of an E-Circular that will
serve as a comprehensive resource to
those that are considering performing
CPT themselves. As such it will focus on
the aspects associated with the selection
of the appropriate CPT rig and cones.
Geophysics Users Group
Geophysics involves the generally noninvasive
investigation of subsurface
conditions by measuring, analyzing and
interpreting the contrasting physical
properties of subsurface materials from
the ground surface or through an
existing borehole. Geophysical surveys
for geotechnical investigations are
conducted to detect/identify materials in
the ground from a few inches to more
Seismic refraction testing (credit: J.W. Ramp
Photography)
than 100 ft (30 m) below the ground
surface. Typical objectives of geophysical
surveys for geotechnical investigations
are determining the depth and
configuration of the bedrock surface,
determining the depth of ground water,
mapping buried debris and fill,
detecting, and locating subsurface
utilities and other buried metal objects,
as well as many other objectives.
The Geophysics Users Group
initially targeted state DOT peer-to-peer
discussions due to the public sector
nature of the A-GaME audience but has
gradually extended out to include other
civil works. The group currently meets
bi-monthly to discuss pertinent topics
in geophysics as they relate to both
transportation and nontransportation
topics including the correlation of
geophysical measurements with
geotechnical parameters, discussions
of the limitations and accuracy of
taken two significant initiatives. The
first is the Data Interchange for Geotechnical
and Geoenvironmental Specialists
(DIGGS) for Geophysics project. This
initiative, currently in its second phase,
will contribute to the ASCE/DIGGS XML
schema by incorporating geophysical
data formatting. The proposed schema
extensions should allow for the storage
and transfer of most any kind of
processed geophysical data that occurs
within a spatial domain. The initial
phase is complete and should significantly
improve data exchange and
interoperability among the geologic,
geotechnical engineering and geophysical
communities to support geoengineering
analysis, design, planning,
construction, data visualization and data
archiving. The ambitious goal of the
overall project is to develop a fully
functional geophysical module in
DIGGS, in partnership with the ASCEGeo
Institute's Engineering Geology and
Site Classification Committee.
The second, multi-year initiative
being undertaken, with support from
DFI and the TRB Standing Committees
on Soil and Rock Properties and Site
Characterization, is to update and
modernize a geophysics webtool
platform, originally developed from a
2003 FHWA manual on geophysics, to
create a reference website for both practitioners
and end users of geophysical
methods, data and model results based
on objectives. The purpose of the
webtool is to provide geotechnical
engineers, contractors and owners with
a basic knowledge of geophysics and
nondestructive test (NDT) methods for
solving specific engineering problems
during geotechnical investigation and
construction. The webtool is intended to
assist in the selection and use of suitable
geophysical and NDT techniques to
evaluate problems for design, planning,
construction or remediation efforts.
DEEP FOUNDATIONS * MAY/JUNE 2023 * 89
May/June 2023

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