January/February 2023 - 62

expected this year. The second research project deals with p-y
curves in both sand and clay soils with the goal of updating
the p-y curves embedded in LPILE and other software based
on results from high-quality lateral load tests at well-defined
sites and subsequent back-calculation of performance. Kyle
Rollins, Ph.D., at Brigham Young University, along with his
students, are also contributing to this effort and final
deliverables are expected this year as well.
A task force of dedicated volunteers from our committee
have developed a consensus document regarding the
simultaneous mobilization of side and base resistance in
most drilled shaft rock sockets. Aspects of thorough site
characterization, informed design, quality construction
practices and detailed inspection are integral to the
conclusion that, in most cases, the mobilization of side and
base resistance in a rock socket occur at compatible
displacements. Exceptions in some unique geologic settings
do exist (e.g., in karst), but are the exception in a national
sense rather than the norm based on review of available bidirectional
load test data where quality site investigation,
construction, clean out and inspection were performed and
documented. The task force has responded to all comments
received during the open review period in which all
members of DFI could review and provide comments. This
marks the final review step in the process of publishing a DFI
consensus document and our committee eagerly awaits
publication by DFI.
Finally, in combination with the European Federation of
Foundation Contractors (EFFC), DFI's research on both support
fluids and working platform safety is ongoing. Regarding
support fluids, the principal investigators are still seeking
access to three additional construction sites in the U.S. where
a few specialty tests could be conducted on bentonite- or
polymer-supported drilled shafts or diaphragm walls. The
specialty testing will be performed by the research team and
very little is needed aside from a short amount of time on your
jobsite. If you are interested in helping by simply allowing
access, please reach out to our committee and we will
coordinate with the research team. Regarding working
platform safety, four methods are available for field personnel
use to evaluate the competency of the working platform upon
mobilization to a job site. The principal investigators
encourage contractors to utilize the four available tools and
provide feedback on the ease of use and effectiveness of the
various methods for adequately assessing the condition of the
working platform. Again, if you are interested in helping by
simply trying the devices, free of charge, please reach out to
our committee and we will coordinate with the research team.
New potential projects on the committee's radar include:
1. Use of air track drilling, possibly in combination with
measurement while drilling technology to aid in the characterization
of bedrock conditions, as well as potentially
avoiding the need for down-the-hole personnel entry for
inspection.
2. Like the consensus document on rock sockets currently
being published, develop a consensus document detailing
the simultaneous mobilization of side and base resistance
in most drilled shafts bearing in soil.
3. Consideration of adjacent ground displacement due to
drilled shaft installation and whether geotechnical
engineers should include estimates for the magnitude of
displacement that may occur in their reports so owners
can be better informed.
As you can see, it is a busy time for the Drilled Shaft
Committee, but we are fortunate and happy to have so many
relevant topics to investigate; it is also wonderful and
humbling to have the volunteers willing to do the work!
CO-CHAIRS SCOTT JACOBS, P.E., AND TERENCE HOLMAN, PH.D., P.E.,
Working Platforms Industry-Wide Working Group
Since the publication of the Recommended Industry Practices for
Safe Working Platforms for Construction Equipment in 2020, the
group has been reaching out to various industry groups to gain
awareness of the document. These groups include the
Association of General Contractors, Occupational Safety and
Health Administration, the National Institute for
Occupational Safety and Health, the Mine Safety and Health
Administration and insurance companies.
The International Association of Foundation Drilling
Dallas. This will be a two-day, interactive
class that details the best ways for drilled
foundation contractors to implement the
recommendations outlined in the
guidance document.
The Federation of Piling Specialists
(ADSC), as a partner in the joint working group, will be
providing an implementation seminar on the Recommended
Industry Practices for Safe Working Platforms for
Construction Equipment Guide scheduled for March 8-9, in
62 * DEEP FOUNDATIONS * JAN/FEB 2023
Jacobs
(FPS) updated its track pressure calculation
spreadsheet in fall 2022. This is a
valuable tool to calculate specific track
pressures for crane or piling equipment
for use in working platform design per
guidelines set out in Building Research
Establishment Report BR470. The tool is available for free from
Holman
January/February 2023

Table of Contents for the Digital Edition of January/February 2023
