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Hitch Rack Ranch Pit Wall Geotechnical Assessment—Supplemental CDRMS Response <br /> NORWEST 65018 <br /> March 2 ,218 <br /> COR PORAT ION Paget <br /> slope to the groundwater level was evaluated as part of Norwest's analyses by varying the defined <br /> groundwater level during the stability analyses. Norwest evaluated a conservative case which <br /> included the assumption of full saturation of the pit slopes as discussed in a later section. <br /> 2.2. Structure <br /> This section describes the major structural information available forthe portion of the HRR property <br /> north of South Turkey Creek. Limited data is available for the proposed pit area, but some aspects <br /> of the structural conditions are expected to be similar to the areas north of the creek given the <br /> similar rock mass conditions, however additional drilling will be required to characterize the <br /> structure of the ultimate quarry pit footprint. <br /> 2.2.1. Faulting <br /> The current understanding of major fault structures in the area is based on surface <br /> mapping, borehole intercepts and regional information.Surface traces of major faults are <br /> shown on Figure 1. Regional information and the intercept from borehole HCO03-15 <br /> indicate that these faults dip near vertical, except the easternmost fault which exhibits a <br /> listric(curved)type orientation with high angles encountered within the proposed mining <br /> pits followed by gradual shallowing of dip to around 35 degrees dip at lower elevations <br /> east of the proposed mining area.Steeply dipping faults that do not undercut the pit walls <br /> are not expected to lead to large scale slope failures.The rock within these fault zones is <br /> generally more broken (RQD< 50%) with slickensides and some clay infill present on the <br /> discontinuity surfaces. <br /> Several seams of sand-like material were intercepted in HCO04-15 at varying depths.These <br /> zones ranged from 0.2 up to 2ft in thickness. It is possible that these seams are related to <br /> unmapped, shallower-dipping faults. Borehole HCO04-15 is located north of Little Turkey <br /> Creek where no mining will occur; however, if similar seams were encountered in the <br /> southern quarry area they could impact interim or overall pit slopes. Additional mapping <br /> and drilling is a requirement as the quarry design is advanced in order to confirm the <br /> orientation and quality of these seams/potential faults and their effect on pit wall design <br /> through the various pit phases. However, given the Phase 1 pit configuration (relatively <br /> shallow highwalls during initial mining of Phase 1 as shown in the cross-section inset in <br /> Figure 1) it is expected that adverse dips can be addressed by adjusting the mining <br /> sequence and direction. <br /> 3. OVERALL SLOPE STABILITY <br /> A Limit Equilibrium "L-E" analysis has been carried out for a cross-section for the highest section of the <br /> Phase 1 pit wall which is approximately 200ft in height. The analysis was carried out using GeoStudio <br /> software SLOPE/W Version 8.4 to evaluate the static and pseudo-static factor of safety for a pit wall <br />