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January 15, 2008 <br />2.0 LABORATORY TESTING <br />Page 6 <br />As each borehole was drilled, selective core samples were collected for lab testing. <br />Ninety-six samples were shipped to AAI testing facilities in Grand Junction, Colorado. A total <br />of 71 tests were conducted: 19 unconfined compression tests (UCS), 4 triaxial compressive <br />strength tests (TCS), 32 point load tests (PL), 7 Brazilian tensile strength tests (Brazilian), and <br />9 fracture direct shear strength tests (DS). Samples were tested in three batches. Test results for <br />each set of tests are presented in the Appendix. <br />Previous lab tests had been performed on cores from several boreholes located within the <br />landslide area.7 A projection of these pre-landslide characterization boreholes (05-G1-CCR <br />through 05-G6-CCR) are shown in Figure 3. The new testing was performed for the following <br />reasons. <br />Previous testing only had one test from the weak layer just above the main L-Seam <br />thought to contain the slide plane. Strength tests of this mudstone would help confirm <br />this being the suspect layer. <br />Tests on post-landslide samples would provide data on current strength state of layers and <br />their variations. <br />Testing could confirm differences between peak and residual strengths since the stability <br />analysis suggested this to be important for the failure mechanism. <br />Results from the recent laboratory testing are summarized in Table 1. The results suggest <br />significant difference in strengths of the mudstone layer and carbonaceous shaley-mudstone <br />layer just above the Main. L-Seam (referred to as L-Roof rocks). Both layers show wide <br />variations in strengths, but the carbonaceous shaley-mudstones are about 30% lower in strength. <br />Comparing data from the pre-landslide test results to the post-landslide test results from Table 1 <br />confirms that the weak carbonaceous shaley-mudstones are about 501/o weaker than originally <br />thought. <br />Table 1 also indicates that the Q-Floor mudstone is at least as weak as or weaker than the <br />weak carbonaceous shaley=mudstone in the L-Roof. From visual observations at the mined <br />highwall face in G-Strike Pit,s the Q-Floor and L-Roof mudstone layers are of similar character, <br />and these tests confirm that they are of similar strength properties. Both the weak Q-Floor <br />mudstone and weak L-Roof carbonaceous shaley-mudstone will be referred to hereafter as weak <br />mudstones layers. <br />7 Agapito Associates, Inc. (2006), "Trapper Mining Inc. (Trapper Mine)-Rock Mechanics Core Testing Results," <br />prepared for Trapper Mining Inc., February 6. <br />8 Agapito Associates, Inc. (2005), "Letter Report - G Pit Highwall Failure 9/15/05 Site Visit," prepared for Trapper <br />Mining Inc., September 27. <br />Agapito Associates, Inc.