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Tonia Perkins <br />July 31, 2024 <br />Page 23 <br />Agapito Associates, Inc. <br />array of panels in the South M Seam, each having 10 entries. Mining in the Q Seam was excluded <br />from this analysis. <br />To assess potential block sliding conditions, a strength reduction factor of 2.5 was applied to the <br />coal in the M Seam, which was shown to induce failure of the web pillars in the previously <br />described models. With support from the barrier pillar, the model came to a state of equilibrium, <br />meaning the panel and slope remained stable. <br />Figure 23 shows the final vertical displacements, with magnitudes on the order of 0.025 ft, or 0.3 <br />inches above the center of the panel. Figure 24 shows yield through a cross section of the pillars. <br />In this plot, it is evident that the web pillar at the center of the panel is fully yielded while the <br />barrier pillar is intact. <br />Figure 25 shows horizontal displacements toward the pit, which are on the order of 0.0075 ft, or <br />0.09 inches, and considered negligible. The model illustrates that even with web pillar failure <br />initiating at the center of the panel beneath the deepest cover, the barrier pillar prevents the failure <br />from spreading laterally along strike of the slope, and the reduced depth of cover on the pillars <br />nearest the slope face provide web pillars with a higher factor of safety that prevents failure from <br />spreading laterally toward the pit. The likelihood of block sliding failure along the coal seam is <br />interpreted to be relatively low.