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2004 Geologic Hazard Field Observations <br />South of Divide Mining Area <br />• Maximum vertical displacement of 11.2 feet is expected within the azea of mining <br />influence of the northern limit of longwall panel E9 in the landslide azea. <br />7.1.2 Maximum Tilt <br />Maximum tilt (Mm) is calculated from differential vertical displacements that were measured at <br />the West Elk Mine monitoring network in terms of the ratio of maximum vertical displacement <br />to overburden depth to the seam being mined (S,~/d) (Table 1). <br />• Panels El to E8: Maximum tilt in these panels is projected to range from 0.007 to 0.037 <br />(0.7 to 3.7 percent) where 8 feet of coal is extracted, from 0.013 to 0.044 (1.3 to 4.4 percent) <br />where 12 feet of coal is mined, and from 0.013 to 0.064 (1.3 to 6.4 percent) where a 14 foot <br />thickness of coal is mined (Table 1). Maximum tilt of 6.4 percent is expected to occur within <br />the azea of mining influence above the western limit of longwail panels EZ and E3 should I4 <br />feet of coal be extracted. <br />• Panel E9: Maximum tilt in this panel is predicted to range from 0.034 to 0.044 (3.4 and 4.4 <br />percent), where 12 feet of coal is mined and from 0.039 to 0.052 (3.9 to 5.2 percent) where <br />14 feet of coal is produced. Maximum tilt of 5.2 percent feet is expected within the area of <br />mining influence of the northern limit of longwall panel E9 in the landslide area. <br />7.1.3 Maximum Horizontal Strain <br />The curves projected for tensile and compressive strain in the South of Divide Mining Area, <br />based on the West Elk Monitoring Network and the National Coal Boazd of the United Kingdom, <br />aze shown in Figure 5 of Exhibit 60B (November, 2004). The tensile strain values obtained from <br />these curves are considered to be conservative for the South-of-Divide mining Area. Tensile and <br />compressive horizontal strains aze calculated, using the values obtained from the West Ells <br />Monitoring azea, as adjusted for the values observed in the Apache Rocks Mining Area, aze listed <br />in Table 1. These numbers aze believed to be conservative, based on annual observations over <br />the last six yeazs in the Apache Rocks Mining Area. <br />C~ <br />831-032.621 Wright Water Engineers, Inc. Page 14 <br />November 2004 <br />