ERDC forensic study saves Corps big money

28 May 2008 -- Vicksburg, Miss. -- ERDC-GSL researchers Ron Wahl and Reed Freeman, recently saved USACE $60 million after providing forensic data and expertise in a lawsuit between USACE and the Daewoo Corp. over a project in the Republic of Palau.

In 2003, USACE's Pacific Ocean Division's (POD) Honolulu Engineering District (HED) began constructing a 53-mile, two lane roadway for the Republic of Palau under a project titled, "Palau Compact Road." The Daewoo Corp. served as the general contractor of the project and Gela's Inc. provided design and project specifications.

Delays in construction

The combination of the high in-situ moisture content of the soil in Palau and the wet climate caused severe delays in roadway embankment construction for the project. To achieve the specified soil density, the contractor was required to dry the soil to a moisture content of about 50 percent. However, the soil could only be dried to this condition with several days of consecutively dry weather.

To expedite construction, USACE representatives, with cooperation by Daewoo and consultation by Tensar Earth Technologies Inc., investigated the possibility of constructing geosynthetically reinforced embankments with soil densities lower than originally specified. The concept of the design was to compensate for lost soil strength with embedded horizontal sheets of geogrid reinforcement. This investigation included the placement of an experimental embankment, which was approximately 300 feet long, 35 feet high and included $40,000 worth of geosynthetic material. HED called upon GSL to provide an independent analysis of the problem and to offer potential solutions.

Wahl and Freeman visited the construction site in Palau to monitor construction and study soil reports. The researchers used measured soil properties and traditional embankment stability analyses to demonstrate that the embankments could be constructed at lower densities and without the geosynthetic reinforcement, resulting in substantial cost savings over the entire length of the roadway.

Wahl and Freeman proposed a method of construction termed "controlled rate construction," which would allow the placement of soil at lower densities with subsequent consolidation of soil (i.e. increasing density and strength over time), provided that the rate of construction was maintained at a pace that would not "over-stress" the soil at any point in time. Because the soil in Palua is silt, as opposed to clay, it consolidates relatively quickly, making the "controlled rate construction" process viable. In addition, because this process would minimize the need for drying soil prior to compaction, it would improve the overall construction rate. Wahl and Freeman formalized these conclusions in a written report and briefed findings of the forensic study to USACE representatives in both Palau and the POD in Honolulu prior to returning to the continental United States.

Wahl and Freeman stressed the importance of constructing an additional experimental embankment using procedures that they detailed in writing. This embankment would contribute to the final roadway alignment, so it would not impose a serious burden on the construction schedule. Soil was to be compacted at densities lower than originally specified and the soil would be tested in accordance with the detailed plan offered by Wahl and Freeman. The plan included soil sampling, testing and simple embankment instrumentation. Upon completion of GSL's report, Daewoo began directing construction and testing associated with the experimental embankment. While Daewoo was still investigating the possible advantages of using geosynthetic reinforcement, they were also considering the option proposed by GSL.

Minimizing future cost

GSL's investigation and proposal had potential for saving the POD construction costs on the order of several hundred thousand dollars and perhaps more than one million dollars. These savings would be in terms of minimizing future costly construction delays due to rainy weather. Also, Wahl and Freeman's plan would eliminate the need for costly materials needed for the original geosynthetic reinforcement design.

In 2004, Daewoo attempted to sue the federal government for faulty specifications. Both Wahl and Freeman provided formal depositions for the U.S. Department of Justice. In 2005, Freeman represented USACE in court for the proceedings of this particular lawsuit. The following year, Brian Smith, past Department of Justice counsel and present chief counsel for POD, informed ERDC that Daewoo lost its attempt to sue USACE for $60 million.

Dr. David Pittman, GSL director, recently met Brian Smith at the POD Senior Leaders Conference in Korea and Smith expressed his sincere gratitude for the work and support that Wahl and Freeman provided in the Palau project and lawsuit.

According to Dr. Gary Anderton, chief of GSL's Airfields and Pavements Branch, "Ron and Reed's excellent work in a forensic study we conducted a few years ago ended up paying huge dividends for the Corps in the courtroom. This is a different kind of success story that should inspire others to realize that ERDC's work has the potential to have a tremendous impact in ways we don't commonly think of."