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1 wedge failures that develop when the plunge of the line of intersection, of two intersecting <br /> joint sets, daylights in the floor of the quarry. This condition should be expected to <br /> icontinue during future mining operations; however, the quarry imposed 50 feet safety <br /> zone should serve to diminish the negative impacts associated with these small wedge <br /> ' failures and the ravelling condition as well. <br /> CONCLUSIONS <br /> The results of the structural geology evaluation of the Spec-Agg quarry, which included <br /> ' field observations, geologic mapping, and stereographic analysis of structural geology <br /> data, indicate that the current quarry configuration is stable. Figure 12 is a plot of the <br /> results of each stereographic analysis relative to the corresponding quarry wall. These <br /> results corroborate the successful performance history, and effectiveness of the overall <br /> mining plan. The evaluation showed that the current orientations and slopes of the quarry <br /> walls with respect to major structural features including faults, shear zones, and foliation <br /> ' planes are favorable for stability. This is enhanced by the absence of hydrostatic <br /> pressures and the current reclamation process. Localized ravelling and small wedge <br /> failures, as depicted in the photographs, and as described herein are likely to continue to <br /> occur. Current operation practices of maintaining the 50 foot wide safety zone and timely <br /> ' reclamation help to minimize the impact of these operations, as will ongoing attention to <br /> minimizing overbreak during blasting. <br /> The prospects for continued stability of the Spec-Agg Quarry are considered excellent <br /> rprovided that none of the factors which maintain the existing equilibrium are altered. <br /> Adherence to current, sound mining practices is important, but natural forces including <br /> hydrostatic pressure and erosion must also be monitored and the analysis re verified if any <br /> significant changes occur. Seismic loading could also have a negative impact, but both <br /> the probability and magnitude of possible seismic shaking are extremely low. <br /> 23 <br />