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4.3 Model Results - "C" Seam <br /> As part of this investigation the "C" seam was modeled assuming room and <br /> pillar mining, a 50 percent extraction ratio, and an extraction height of 6 ft. <br /> As has been mentioned previously, it would appear from the monitoring data that <br /> many portions of the mine have not undergone any subsidence to date. In fact, <br /> with an extraction ratio as low as 50 percent, much of the mine would likely <br /> demonstrate long tern stability. However, even in areas which have not subsided <br /> to date due to the very thin interburden between the "B" and "C" seams, we would <br /> anticipate that "B" seam minim and the subsidence associated with the "B" seam <br /> would, in any event, trigger subsidence associated with the "C" seam. <br /> Results of the modeling has indicated that subsidence within the "C" seam is <br /> likely to reach a maximum value on the order of 2.0 ft. <br /> As mentioned previously, we have identified four monitoring sites which <br /> appear to have undergone subsidence associated with "C" seam mining. Table 1 <br /> shows the monument number, its north and east coordinates, and manes the <br /> calculated subsidence at that location with the actual measured subsidence. As <br /> can be seen from this table the correlation is, in general, quite good. <br /> 4.4 Model Results - "B" Seam <br /> Subsidence for the proposed "B" seam mining was modeled utilizing an <br /> extraction height of eight feet and an in panel extraction ratio of 65 percent. <br /> The maximim, calculated subsidence for the "B" seam is on the order of 3.4 feet. <br /> This maxiTmim value occurs in many of the panels that border the outcrop barrier <br /> pillars in the northwest portion of the mine. In the more southerly array of <br /> k <br />