May/June 2023 - 88

* MWD: the technique that relates the
data obtained during drilling such as
torque, rotation speed and downward
pressure with information on
the in-situ soil and rock stratigraphies
and properties.
For all three methods there is (and has
been) a vast body of knowledge in
numerous books, scientific papers and
articles; however, this hasn't resulted in
these methods being commonly applied
for subsurface soil and rock investigations.
It was, therefore, decided to set
up users groups for these three A-GaME
methods. These groups provide an open
forum, irrespective of experience level,
where people interested in a subject
matter, e.g., as manufacturers, users or
decision makers, can come together and
exchange ideas regarding each of these
methods. In addition, and possibly more
importantly, these groups bridge a wide
range of organizations, as they have
been created in cooperation with the
FHWA, American Society of Civil
Engineers (ASCE) Geo-Institute, departments
of transportation (DOTs), DFI and
Transportation Research Board (TRB)
Committees AKG20 (Standing Committee
on Soil and Rock Properties and
Site Characterization) and AKG60
(Standing Committee on Geotechnical
Instrumentation and Modeling).
The structure of these groups is
i n t e n d e d t o e n s u r e t h a t t h e
membership is (or at least can be) all
encompassing, but it also provides a
reminder of how these subsurface
investigation techniques should be
applied in practice. Just as the members
in the individual users groups
compl ement each o ther, when
integrated, these site investigation
techniques do the same. Together, each
with their own benefits and limitations,
they are part of a wide range of tools
that provide, either by themselves or in
combination, a more effective site
characterization that is required to
avoid schedule delays and cost
overruns that affect not just major
infrastructure project delivery, but all
construction projects in general.
In 2021, these three users groups got
started and since then have been
involved with a wide range of activities.
Cone Penetration Testing
(CPT) Users Group
During CPT, a cone is advanced through
the soil at a constant rate of 20
mm/second (0.78 in/second). The force
on the cone tip required to penetrate the
soil is measured, and the cone tip
resistance is then calculated by
dividing that force by the cone base
area. Behind the cone tip there is a
friction sleeve and the force exerted on
the friction sleeve is also measured. The
friction sleeve resistance is then
calculated by dividing that shear force
by the surface area of the friction
sleeve. These days, most cones are
capable of registering porewater
pressure induced during advancement
of the cone as well.
The CPT users group meets monthly
to discuss specific topics to provide a
better understanding of the planning
and execution of this soil investigation
technique as well as the interpretation
of the data that are generated during its
use. These presentations are given by a
wide range of speakers, representing
state DOTs, academia, service providers
and equipment manufacturers. Taken
toge t he r t hey p rov i de an a l l -
encompassing overview with the
objective that this method, which was
first developed more than 90 years ago,
is no longer viewed as a new technology
that needs to be proven, but as one than
can be and is applied more widely. At the
same time new insights are shared, for
example, during a recent presentation
by Peter Robertson, Gregg Drilling &
Testing, where he shared a new
approach to identify peat from the CPT
data based on research performed in the
Cone penetration testing (credit: J.W. Ramp Photography)
88 * DEEP FOUNDATIONS * MAY/JUNE 2023
Collecting data (credit: J.W. Ramp Photography)
May/June 2023

Table of Contents for the Digital Edition of May/June 2023
