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and the dip angles of the foliation joint surfaces will vary based on this <br />undulation. <br />The concern for future movement of the slide will be warranted upon <br />removal of the next bench. The failure surfaces (i.e. the surfaces along <br />which movement has occurred) remain at a "residual strength" and <br />therefore are less resistant to additional loading. Although the current slope <br />configuration appears to be stable, the failure mechanism could be <br />reactivated, resulting in movement of additional material. It is also possible <br />that the dip angle of the foliation may change such that no further instability <br /> occurs. <br /> <br /> 11) The highwall and the area above the highwall of the asphalt plant was <br />' visually inspected as part of the field inspections performed on March 20 <br />' and 22, 2002. Unlike the highwalls for the areas currently being mined, the <br />ll <br />f <br />l <br /> bedrock in the highwa <br />the asphalt p <br />o <br />ant is sedimentary in origin, <br />' consisting of shales and sandstones upturned to near vertical orientations. <br /> The asphalt plant is currently in the process of being upgraded with <br />' significant structural and foundation work being performed. It appeared that <br /> some excavation of the small slope to the north of the plant had been <br />' performed which resulted in a reduced slope angle and exposed the shale <br /> (Photo 10). The exposed shale is expected to deteriorate over time due to <br />' the wet-dry and freeze-thaw cycles. It also appears that a slab of <br /> weathered shale had been removed from the main highwall immediately <br />' west of the plant. (Photo 11). Neither of these modifications are believed to <br /> decrease the stability of the slopes. No other significant changes in the <br />' condition of the highwall were noted and no major cracks, settlement, or <br /> ponding areas were noted in the ground surface above the highwall, leading <br />' us to conclude that the asphalt plant highwall is stable under the current <br />' conditions. <br />' 2002 Spec-Agg Annual Report Page 11 <br />