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Bulldog Mine TailinRS Ponds Evaluation <br />_ -t.0 GEOTECHNICAL ANALYSES <br />d.l Geotechnical Laboratory Testing <br />Geotechnical laboratory testing was performed on selected samples to assess the physical <br />characteristics of the tailings in the Upper and Lower Tailings Ponds. More specifically, testing <br />was performed on relatively undisturbed Shelby tube and acrylic tube samples to assess the <br />degree of saturation, hydraulic properties, and consolidation state of the tailings. A summary of <br />the schedule of samples selected for geotechnical testing is shown on Table 4.1. <br />Laboratory testing was performed by Advanced Terra Testing in Denver, Colorado under the <br />direction of SMI. This testing included moisture content (ASTM D2216) and density (ASTM <br />D2937) measurements, consolidation testing with time-deformation measurements (ASTM <br />D2435) and without time-deformation measurements, mechanical grain size analyses (ASTIvI <br />D422), Atterberg Limits (Liquid and Plastic Limits) determination (ASTM D4318), and <br />measurement oY the specific gravity of solids (ASTM D854). Laboratory measurement of the <br />vertical permeability of two samples was made in a flexible walled triaxial cell using back <br />pressure saturation procedures and a flow pump to provide a constant flow of water through the <br />specimen (ASTM D5084). In addition, the neaz-surface tailings density and moisture content <br />was measured at two locations, one neaz each of the oxygen profile and flux measurement sites. <br />The moisture content of the samples obtained during these two tests, together with moisture <br />contents of other tailings samples obtained during the supplemental field investigations, were <br />measured by Landmazk Engineering, Ltd. of Loveland, Colorado under the direction of SMI. <br />Geotechnical laboratory test results aze summarized on Table 4.1. Detailed test results aze <br />included as Appendix B of this report. <br />4.2 Tailings Moisture/Saturation Conditions <br />The degree of saturation of the tailings samples were calculated from the laboratory <br />measurements. Laboratory test results for the bulk dry density, moisture content and specific <br />gravity of solids of relatively undisturbed Shelby tube and acrylic tube samples were used in <br />these calculations. Table 4.1 summarizes the estimated degree of saturation calculations. Seven <br />of the eight samples tested exhibited high degrees of saturation (in excess of 75 percent), with <br />Homesrake d~Itnmg Compm4' Slreplrerd bLller. /rte <br />p~ir*-unn„n~g..pr 1J ,~pnl ll. /99r <br />