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mining method utilizes a high-pressure water jet cutting machine and diamond wire saws. <br /> Neither of these machines cause fracturing to the surrounding rock while rock is being <br /> excavated. <br /> The included Gallery Map, found in Appendix 2, shows the existing gallery as compared to the <br /> currently submitted proposed DRMS plan. It should be noted that pillars proposed in the <br /> submitted DRMS plan are currently partially excavated. This is not a safety concern due to the <br /> excessive safety factor in the design. The 25' x 25' pillar design is included in Gallery Map, <br /> Appendix 2. This design is easily achievable under the current conditions. Recommendations to <br /> the Operator include to leaving the rock between the surface and Pillar A intact similar to the <br /> currently submitted DRMS plan. Future pillars are now located on the Gallery Map Appendix 2. <br /> Only Pillar D has been reached by mining at this point. Pillar D is now shifted to the northwest <br /> to catch a set of intersecting fractures. Typically, it is ideal to intercept fractures within a pillar. <br /> This reduces the potential for small wedge failures related to intersecting fractures. <br /> In most underground mines and quarries, to ensure safe working conditions and to prevent <br /> subsidence, underground support methods such as rock bolt and shotcrete are used to supplement <br /> the support that may be provided by rock mechanic designs of the openings. In most mines and <br /> quarries, excavation is advanced by the use of drilling and blasting techniques. Such methods <br /> cause near-surface fracture damage to the walls of such openings. These blasting induced <br /> fractures over time can propagate and ultimately cause masses of rock to cave into the <br /> underground openings. To avoid this rock bolts,timber supports and shotcrete linings may be <br /> used; however, in this case none of these preventive measures are necessary. <br /> The Rose Red quarry is one of the rare cases where no additional support is required to safely <br /> maintain the integrity of the openings for long periods of time. To show this is the case, a RMR <br /> (Rock Mass Rating) classification factor was estimated for the rock mass of the Rose Red <br /> Quarry. The Rock Mass Rating system was developed by Bieniawski in 1989 to provide a <br /> statistical method to classify the required underground support methods needed for underground <br /> openings. It considers rock strength, percent core recovery, discontinuity characteristics and <br /> ground water conditions. The Rose Red Quarry RMR is estimated at 92. A RMR classification <br /> number between 81 and 100 indicate that no underground support is required. The Rose Red <br /> Quarry has a very high RMR and with no further blasting in or near the underground workings, <br /> Rose Red Quarry Geotechnical Report 18 <br />