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<br />Aggregate Industries Morrison Quarry GEI Consultants, Inc. <br />Geotechnical Addendum, 2016 Annual Report 15 January 2017 <br />The additional loading from the mining material on the instability area increases the <br />possibility of additional movement/failure of the bench. As such, GEI advises AI to monitor <br />and mitigate any additional loading of Bench 6820 caused by waste rock from mining at <br />uphill highwalls. <br />In areas inspected for the 2016 Geotechnical Addendum, no conditions were observed that <br />could lead to large-scale slope failures. There is likely a low probability of large wedge or <br />toppling failures due to the joint and foliation orientation and RMR values observed in the <br />rocks. Additionally, there is likely a low probability of large plane failures along foliation <br />surfaces that can occur when the foliation surface dips into the highwall face at angles of <br />38 degrees or greater. There are areas where the unfavorable foliation conditions were <br />observed or where small-scale wedge or toppling failures could occur, but the resulting <br />blocks are anticipated to be relatively small and contained on the benches. Most of the <br />unfavorable foliation orientations will likely change during mining operations due to the <br />highly variable nature of the foliation planes; however, small-scale toppling or wedge <br />conditions are likely to persist during mining. Kinematic analysis utilizing data obtained <br />during the 2016 review supports the above conclusions. The results and associated stereonets <br />are provided in Appendix B. <br />4.1 North Quarry <br />Observations in the North Quarry on January 12 and January 13, 2017 indicate: <br /> No major failures occurred last year; <br /> Minor, localized sloughing and raveling occurred; <br /> Nearly all localized rockfall was contained on the benches. <br /> Continued observation of the localized rockfall areas and the reclaimed bench near <br />mine office for signs of slope instability is recommended for 2017. <br />4.2 Central Quarry <br />Observations in the Central Quarry on January 12 and January 13, 2017 indicate: <br /> No major failures occurred last year; <br /> Minor, localized sloughing and raveling occurred; <br /> Nearly all rockfall was contained on the benches. <br /> The stabilized slope in the northeast section of the Central Quarry did not exhibit <br />any instability or large erosional features; <br /> A small groundwater seepage area is visible on the west (east facing) side of the <br />Central Quarry. This seepage should be monitored periodically during 2017. If the <br />condition of the area worsens, engineering consultation is recommended.