September/October 2023 - 96

Cutoff wall completion
the required hydraulic conductivity of
-6
1x10 cm/s. The average unconfined
compressive strength was within the
50-250 psi (345-1,725 kPA) range, and
no specimen was either below 30 psi
(207 kPA) or above 275 psi (1,896 kPA), as
required by the specifications. Horizontal
elevation cuts of the wall generated
in 10 ft (3 m) vertical intervals demonstrated
the continuity of the cutoff wall.
All 22 verification borings drilled along
the wall confirmed the continuity of the
wall and proved its homogeneity.
The jet grouting barrier met all
specification requirements, too. The
total of just over 160 overlapping columns
produced a curtain that reached
the minimum required width of 30 in
(760 mm). All wet grab samples tested
at least one order of magnitude lower
t h a n t h e r e q u i r e d h y d r a u l i c
-5
conductivity of 1x10 cm/s. A 3D model
of the installed columns proved the
continuity of the jet grouting barrier,
confirmed in the field by 11 verification
borings, each one drilled at the
center of a cluster of three columns. The
integrity of the utilities was maintained
throughout the whole process and no
significant movement was recorded.
Conclusion
The project faced several challenges
throughout its whole duration. Some
challenges were expected such as the
technical complexity, due to several
factors such as the depth of the wall, the
hardness of the bedrock and the design
of the jet grout curtain; or the logistical
complexity, due to the presence of many
utilities. Some challenges were due to
worse than anticipated conditions, like
the high slurry overconsumption
caused by the higher-than-expected
permeability of the gravel layer. Other
ones were unforeseeable, like the
COVID-19 pandemic that directly
affected the lives of millions of people,
disrupted supply chains and transportation,
and made planning extremely
difficult; or like the anomalous severe
weather events that impacted project
operations. Nevertheless, the contractor
was able to produce a high-quality final
product and the project was completed
on time and within budget, to the
satisfaction of USACE.
Matteo Bertoni is a preconstruction manager
for Bauer Foundation. He was the East St.
Louis Deep Cutoff Wall project manager
from November 2019 to September 2021
and from August 2022 to project completion.
Eric Piel, P.E., is a project engineer and
contracting officer representative for the U.S.
Army Corps of Engineers. He was the
contracting officer representative for the
East St. Louis Project.
Amr Ragy is vice president of strategy
and preconstruction for Bauer Foundation.
He was the East St. Louis Deep Cutoff Wall
project executive.
Osvaldo Valdez is a project manager for
Bauer Foundation. He was the East St. Louis
Deep Cutoff Wall project manager from
October 2021 to July 2022.
Col. Kevin Golinghorst visits the jobsite during the COVID-19 pandemic
96 * DEEP FOUNDATIONS * SEPT/OCT 2023
September/October 2023

Table of Contents for the Digital Edition of September/October 2023
