Solutions provided by Innovative Compactor
The construction 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.
“One phase,” 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.
“Because of 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.
Besides multi-lift 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.
The multi-talented 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.
This versatility – 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.