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improvements in capabilities of the mining equipment planned for the Dove Gulch area <br />(Stewart 2005). <br />5.3 Surface Deformation <br />Figure 14 presents surface subsidence over the analyzed five longwall panel block, <br />Upper B Seam, Dove Gulch. Predicted maximum subsidence is 9 ft within the longwall <br />panel areas and less than 4 ft over the gate pillars. Based on similarities in geologic and <br />mining plans for the Upper D and Upper B seam longwall blocks, surface movement in <br />Dove Gulch are expected to be similar to that experienced in the Dl-D9 panel areas. <br />Maximum subsidence is expected to be 15% higher as influenced by the higher extraction <br />height presently planned for Dove Gulch. <br />Predicted tensile strains along two north-south cross sections of interest (A and B <br />passing through two sets of springs) are presented in figures 15 and 16, respectively. In <br />these figures, we have presented horizontal strain patterns while accounting for variations <br />in topographic and mining conditions. Figure 15 clearly shows final compression within <br />the center of the panels and tension near the gate pillars. Tensile strains are significantly <br />reduced at location B to the east of longwall extraction area. Over the extracted portion of <br />the panels, however, surface strains are generally higher at lower elevations. This <br />indicates a greater potential for surface fracturing over shallow cover to the east of the <br />reserve. Some fracturing is also possible at higher topographies as indicated by regional <br />experience. <br />Using a criterion suggested by Singh and Bhattacharya (1984), calculated strains <br />reach levels that may cause surface fractures (figure 15). Fracturing is more likely to <br />occur over panel boundaries and gate roads, particularly to the east under shallow cover. <br />Many of the fractures forming in front of the face should heal due to compression and <br />settling of the surface, but some of the fractures in tensile zones over the gate roads and <br />near panel boundaries may remain open for a short time. Subsequent movements over the <br />gateroads caused by long-term pillar failure may reduce strain and heal some of the <br />fractures formed above the gateroads. <br />Maleki Technologies, Inc. Page 32