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' operation(south-facing slopes with south dipping, da li htin Joints), <br /> CAMAS modified mining in the North Quarry to east to west to create <br /> ' interim active mining slopes that are more east-facing and, therefore, more <br /> stable with respect to the prevailing south dipping joints in this area. <br /> ' Based on the conditions observed with the present exposures, the rock mass at <br /> the northeast area of the North Quarry is tentatively classified as "poor" in <br /> terms of the previously-established baseline conditions. This classification is <br /> ' based primarily on the adverse orientation of the primary joint set along <br /> foliation which dip out of the slope (daylight). Additionally, the rock mass <br /> within the weathered zone is classified as "poor" based primarily on the low <br /> ' unconfined compressive strength of the parent rock material. The large joint <br /> feature noted above is a direct result of this situation. In addition to this <br /> condition, other localized areas of instability were observed and are expected <br /> ' to be of continued concern during further development in this area. <br /> Based on these conditions and on comparisons with baseline conditions for the <br /> analyses, slopes at the east end of the North Quarry are presently being <br /> excavated at an inclination of approximately 1H:1V or flatter. This <br /> classification and excavation geometry may change as additional or different <br /> ' rock is exposed in this area and as additional observations are made. <br /> At present, work in the North Quarry is not at the ultimate limit of the <br /> ' planned excavation, therefore, precision blasting techniques are not presently <br /> being used. When excavation occurs at the proposed quarry walls and if the <br /> slopes are to be excavated with an overall inclination exceeding 1H:1V, <br /> ' precision blasting techniques are planned. <br /> ' 17 G:\PROJECTS\20200\002\96ANNRPT.WPD <br /> •® a <br />