DFI Magazine March/April 2020 - 69

TECHNICAL ACTIVITIES

New Co-Chair for Seepage Control Committee
Join DFI in welcoming Gregg Batchelder Adams, P.E., U.S. Army
Corps of Engineers (USACE), as the new co-chair of DFI's Seepage
Control Committee. He joins CoChair Michael Kynett, P.E., MBK
Engineers.
Batchelder Adams has close to 40
years of experience in civil and
geotechnical engineering. He is
currently a lead civil engineer for the
USACE Risk Management Center
located in Colorado. Batchelder
Adams has worked for a building
contractor, a state highway agency,
two globally focused engineering
consulting firms, and for the U.S. Department of the Interior and
Department of Defense. For the past 30 years, he has focused on the
evaluation, inspection, design, construction and risk assessment of
dams and levees throughout the U.S. and abroad. He has a Bachelor's

Mary Ellen Bruce Large, P.E., D.GE
Director of Technical Activities
melarge@dfi.org

degree in civil engineering from the University
of Vermont and a Master's degree in civil
engineering from the University of New Hampshire.
DFI and federal and state agencies established the Seepage
Control Committee as a collaborative forum to discuss industry best
practices for seepage cutoff and foundation improvement of water
infrastructure projects. The goals of the group are to promote mutual
understanding of technologies, appropriate specification models,
responsible contracting and procurement processes and effective
quality assurance/control. This owner and practitioner group is
aimed at improving communication, aligning expectations, and
defining common goals to generate the ultimate benefits of improved
safety and quality and reduced construction risk and project cost.

COMMITTEE CHAIR JONATHAN HUFF, P.E.

Augered Cast-in-Place and Drilled Displacement Pile Committee
Considering Large-Diameter ACIP Piles
Oftentimes in the design of deep foundations for a structure, a
single deep foundation element is included under building
columns. Perhaps the most commonly used single support element
is a drilled shaft. However, with the continued advancement of
drilling equipment capabilities, the use of a single, high-capacity,
large-diameter augered cast-in-place (ACIP) pile is becoming more
and more common. ACIP pile diameter capabilities have increased
to as large as 48 in (122 cm), and often make for a highly effective
single support element under a column. However, a commonly
perceived roadblock in the design of these single ACIP pile
supports is sometimes encountered: Is a single pile stable without
lateral support from grade beams?
The International Building Code (IBC) makes recommendations
regarding the stability of deep foundations in Section 1810.2.2. The
code states that "deep foundation elements shall be braced to provide
lateral stability in all directions." This can be done with the use of (a)
grade beams, (b) pile groups under a cap, or (c) a single deep
foundation element of sufficient diameter to be considered
adequately braced on its own. The code further details the requirements of option (c) by stating, "Isolated cast-in-place deep

foundation elements without lateral bracing
shall be permitted where the least horizontal
dimension is no less than 2 ft (0.61 m),
adequate lateral support in accordance with
Section 1810.2.1 is provided for the entire
height and the height does not exceed 12 times
the least horizontal dimension."
Since ACIP piles are often quite long with respect to their
diameter, some engineers will say, "Look! Your pile is longer than
12 times the diameter! You don't meet the requirements of the
isolated deep foundation element! You have to use pile groups
instead of a single pile." This evaluation seems so perfectly
counterintuitive. Is a pile somehow less stable laterally when it is
drilled deeper than 12 times its diameter? Why did the code writers
choose the word "height" instead of "length" or "depth"? Why are
drilled shafts not held to this same requirement?
In an effort to further understand this code requirement and
ensure that deep foundations are designed in a manner that meets
the intent of the building code, the ACIP/DD Pile Committee is
performing research and will write a white paper on this topic. The
paper is expected to be finalized in 2021, so stay tuned!

DEEP FOUNDATIONS * MAR/APR 2020 * 69

DFI Magazine March/April 2020

Table of Contents for the Digital Edition of DFI Magazine March/April 2020