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Material Facility y(pcf) (deg) C(psf) Citation <br /> Overburden SGOSA 125 39 0 AMEC, 20114 <br /> Ore SGVLF 110 40 0 AMEC,20115 <br /> Overburden ECOSA 115 39 0 Adrian Brown' <br /> Similarly, unconsolidated foundation materials have been modeled in past engineering <br /> evaluations as the following: <br /> Material Facility y(pcf) (deg) C(psf) Citation <br /> Foundation AGVLF 120 40 0 SWC,2008 <br /> Foundation SGOSA 125 39 0 AMEC, 2011 <br /> Foundation SGVLF 150 40 0 AMEC, 2011 <br /> Colluvium ECOSA 120 29 0 Adrian Brown <br /> To complement the existing data, NewFields obtained bulk samples of overburden and <br /> colluvium materials at the ECOSA for characterization and strength testing. Direct shear <br /> tests were run in an 8-inch square shear box under saturated conditions. To comply with <br /> ASTM D3080 test standards that provide recommendation on maximum particle size as <br /> a function of the shear box size, only minus 3/4-inch material was used for the test. The <br /> measured strength of the materials were: <br /> Sample ID Friction Angle Cohesion <br /> (deg) (psQ <br /> Overburden 42.1 65 <br /> Colluvium 40.1 0 11 <br /> It is our opinion that the strength of both the overburden and colluvium found at the site <br /> are well constrained by historic information and the recent test data, and thus the lower <br /> prescribed factors of safety from DRMS' Table 1 are appropriate. <br /> • Potential for saturated colluvium. Studies have shown an often overlooked weakness in <br /> overburden stockpile stability is the interface between the overburden and the <br /> underlying native material. Furthermore,the recent fresh water pipeline failure under <br /> the ECOSA and statements in the Hydrogeochemistry Evaluation(Vol I1, paragraph <br /> 3.6.6)"under high infiltration conditions, some of the infiltrating precipitation water <br /> will flow along the surface of the boulder till, and emerge at the northern downhill tow <br /> [sic] of the ECOSA" suggest a likelihood of a saturated colluvium. Please factor this <br /> into the slope stability analyses. <br /> AMEC Earth and Environmental(2011). "Cripple Creek& Victor Gold Mining Company Squaw Gulch Overburden <br /> Storage Area Including Mill Platform Stability Evaluation",January 5. <br /> 5 AMEC Earth and Environmental(2011). "Cripple Creek& Victor Gold Mining Company Squaw Gulch Valley <br /> Leach Facility Design", September 1. <br /> 'Adrian Brown(2012). "Cresson Project, East Cresson Overburden Storage Area Evaluation,"Project No. 1385E, <br /> February 24. <br /> Page 19 of 30 <br />