2006-12-12_REPORT - M1974004 - Laserfiche WebLink

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However, all of the wedges indicate that sliding will not occur unless friction angles are less than 33°, therefore showing that they are stable for the existing 45° slope angle. I Foliation plane F-3 intersects joint P-5 within the daylighting envelope and ' therefore, if this foliation is located in the eastern wall area sliding could occur. The stereonet plot also shows that F-1, F-2 and F-3 intersect, resulting in a ' plunge of line of intersection less than the angle of the slope face and thus indicating the potential for sliding, although it is questionable at this time if the ' foliations would occur in the same place to allow for this relationship to occur ' The emergence of F-2 and F-3 as definitive discontinuity sets have been identified only over the past three years as a result of the 2003 geotechnical investigation, the 2004-2005 field mapping efforts, and the current 2006 mapping effort. To date, not enough data have been collected to define the extent of the ' F-2 or F-3 discontinuity sets or to delineate if all of the foliation discontinuities occur in the same location simultaneously. Or if localized faulting within the ' quarry has resulted in "structural blocks", or regions where the dominant foliation sets occur separately, although more data are required to fully support this hypothesis. Until further data are collected, the intersection of the foliation planes (F-1, F-2 and F-3) will not be evaluated in the wedge stability analyses presented herein. ' For the nearly vertical bench face (prior to reclamation), additional potential wedges may exist due to the steep overall slope angle. These wedge failures ' have been observed occasionally on the east wall and are localized in extent. The development and size of these wedge failures will be controlled by the ' discontinuous nature of the discontinuities mapped in the quarry. -19-