provided by Innovative Compactor
of Koppers Company, Inc’s Superfund Site at the Feather River
Plant in Oroville, California was awarded to Baldwin Contracting Company.
However, the Chico, California – based contractor ran into significant
challenges in the construction of the retention basin. The project involved
constructing a clay liner for an RCRA-equivalent hazardous waste cell,
and the site was comprised of extremely hard Lincoln Clay, making compaction
quite difficult. According to Robert May, Baldwin’s general superintendent,
this phase of the project presented considerable difficulty.
said May, “required a three-foot clay liner over a four –acre
site, compacted to 93 percent minimum compaction with very tight moisture
tolerances on a modified proctor. We tried using several compactors
including, a heavy self-propelled sheepsfoot, a vibratory pad drum,
a 20 ton rubber tire, and a double drum sheepsfoot. We were unable to
achieve passing tests with any consistency using any of these types
of compactors and our cost was considerably over budget.”
Since the very tight
moisture window rendered the existing equipment on the project ineffective
at compacting the hard clay, May was forced to find an alternate method
as quickly as possible. “I remember seeing the Impactor 2000 at
ConExpo in the spring”, May recalled. After several test pads
and intensive trials with an Impactor 2000, and favorable results, the
equipment and method was approved for use.
According to the
senior project engineer, Julio Badel, of TRC Environmental Solutions
Inc., “Once we became familiar with this piece of equipment, operations
resumed effectively, yielding excellent production rates and good field
and laboratory test results. Measured permeability values of the clay
liner were less than 1.0 centimeters per second as specified.”
For soil compaction,
the Impactor is equipped with a leveler on the rear so that it can smooth
or seal. Teeth are used to create a good bond between lifts. Manufacturer’s
sources rate the system’s output at approximately six-times that
of conventional compactors.
its attention-grabbing square wheel, the Impactor 2000 was referred
to on this project as the “Fred Flintstone-mobile”,”
informed May. But the real attention was generated by the machine’s
ability to achieve the compaction window specified to meet shear strength
and permeability requirements.
“Once we proved
the Impactor 2000, we parked all of the other compaction tools and we
were able to complete the job on time,” concluded May.
compaction, the Impactor 2000 has proven to be very beneficial for over-excavation
type projects. In normal over-excavation, 2 to 3 foot of earth is removed
and placed back in 6-inch lifts. Each lift is individually adjusted
for moisture and then compacted. With the Impactor method the soil is
not moved. Instead, it is ripped to a depth of 2 to 3-feet. Following
the ripping process, the soil is adjusted to its optimum moisture. After
grading the surface smooth, it is compacted using multiple passes of
the Impactor 2000 to achieve the required density. Quite often 6 to
8 passes will achieve 95% or greater. The Impactor 2000 method has been
proven to provide huge cost savings in this application alone.
Impactor 2000 also provides an economical solution for pavement breaking.
It can be used to break concrete for removal, rubblization, bar debonding,
and “crack and seat”. According to company representatives
it can break a mile of two-lane concrete highway in three and a half-hours
with the largest debris being around 16-inches.
– the ability to use one system for both soil compaction and concrete
breaking – is certainly an added plus for many construction firms.
And like Baldwin Construction Company discovered, when certain applications
for deep lift soil compaction prove too difficult for the more traditional
soil compactors, the Impactor 2000 will provide the solution.