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• GHMXSIopeEvaluation <br />1. INTRODUCTION <br />Cripple Creek & Victor Mining Company (CC&V) is proposing to undertake the Globe Hill Mine <br />Expansion (GHMX) by re-mining the existing backfill in the former Globe Hill Mine, and deepening <br />and expanding mine to access ore-grade material at depth (Plate 1). The mine is located in an historic <br />mining district, which has been mined since the 1890s. The original Globe Hill mine was developed in <br />the period 1995-1997, and was backfilled by 2003. <br />This report presents the available geotechnical information for the GHMX project. Using this <br />information a slope design has been performed, using the Hoek and Brown slope design method (Hoek <br />and Brown, 1997; Hoek, 2001) for the rock slopes, and a frictional analysis for the slopes that will be <br />largely in highly fractured and weathered material. The report presents the analysis and the proposed <br />design of the slopes in the GHMX. <br />2. ROCKMASS <br />2.1 Information <br />The slopes in the GHMX will be excavated in the Cripple Creek volcanics, predominantly Cripple <br />Creek breccia. Detailed investigation of these materials has been performed by the drilling of a total of <br />• 26 coreholes into the material that will form the walls of and be excavated by the GHMX. The locations <br />of the coreholes are shown on Plate 1, and the logs of the core holes are provided in Attachment 1. <br />The coreholes were drilled in three campaigns: <br />1. 1990/1991 Geotechnical Drilling Program. A total often geotechnical boreholes (GHC-1 <br />through GHC-10) were drilled as part of the original design of the Globe Hill Mine. The <br />geotechnical logs of these holes provide varied geotechnical information. However, no strength <br />testing data from this program appears to have survived. All of the holes were drilled within <br />what is now, or will become, excavated material. <br />2. 2006/2007 Metallurgical Drilling Program. A total of 14 metallurgical core holes (GHC-06-595 <br />through GHC-07-607) were drilled in 2006-2007 to evaluate expansion of the Globe Hill mine. <br />The holes were drilled predominantly to the west of the prior excavation, and some penetrated <br />the expected wall rock of the GHMX. The material recovered was logged, photographed, point <br />load tested, and then crushed for assay and chemical analysis. <br />3. 2007 Geotechnical Drilling Program. Two geotechnical core holes (GHT-07-O1 and GHT-07- <br />02) were drilled through the potential east wall of the GHMX, to check the apparently very <br />weak and disturbed material that will make up that wall. The material recovered has been <br />logged, photographed, tested (predominantly by direct shear methods), and sent for assay and <br />chemical analysis. <br />• <br />Report1385E.20071126 <br />