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• Samples obtained from the exploratory holes were examined and clazsified in the laboratory by the <br />project engineer. Laboratory testing was performed on these samples to determine their classification, <br />moisture content, dry density, and strength. Results of the laboratory testing are shown in Figures 5 <br />through 11 and summarized in Table 1. The testing was conducted in general accordance with <br />recognized test procedures, primarily those of the American Society Cor Testing and Materials <br />(ASTM). <br />Index Properties: In order to identify soils and classify them into categories of similar engineering <br />properties, the Unified Soil Classification System (ASTM D-2487) was used. This system is based on <br />index property tests, including the determination of natural water content (ASTM D-2216), liquid <br />limits (ASTM D-423), plaztic limits (ASTM D-424) and grain size distribution (ASTM D-422). Results <br />of the moisture content, dry density, Atterberg limits and the percent of soil pazsing tfte U.S. No. 200 <br />sieve have been summarized in Table 1. In addition, the test results are shown on the logs of ttte test <br />holes at the depths at which the samples were taken. <br />Triaxial Shear Tests: Triaxial shear testing was performed on relatively undisturbed samples of the <br />overburden materials, and performed on remolded materials from the proposed embankment azeaz. <br />• The test consisted of subjecting a cylindrical specimen to an all-around pressure and an axial load <br />varied independently of the all-around pressure. The all-around pressure was applied in a Iluid-filled <br />chamber and the axial load was applied by means of a piston passing through the chamber top. <br />Porous discs were placed against the bottom of the sample which was wrapped in a watertight <br />membrane and [he discs were connected [o the outside of the chamber by tubing. The water pressure <br />in the pores of the sample can be measured through these tubes when drainage from the sample is not <br />permitted. When (low is permitted, the quantity of water passing into or out of the sample upon <br />loading can be measured. <br />Consohdated, undrained triaxial shear testing waz performed on selected samples. The samples were <br />saturated and the chamber pressure raised incrementally. The samples were allowed to consolidate <br />under the applied chamber pressure until no excess pore pressure remained. Valves on the porous <br />tubes were then closed and axial load was applied to the sample. The axial stress and strain within the <br />sample were meazured az the axial load was increased to failure. The consolidated, undrained test is <br />called the R-test. The rate of strain selected was based on an estimate of the coruolidation <br />characteristics of the material. Results of the strength tests are shown in Figures 12 to 14. <br /> <br />lob No. 91-562 Ground Engineering Consultants, Inc. _ Page 3 <br />