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• previously carried by the coal in a caved area is transferred <br />over some finite distance into the adjacent, uncaved areas. This <br />finite distance is considered to be the load transfer distance. <br />To prevent this loading from impacting the pillars in Panel C, a <br />barrier pillar must be sized to support both the normal <br />overburden load plus a portion of the load transferred out of the <br />adjacent caved area. <br />This load transfer distance is related to the overburden depth <br />and the strength of the overburden strata. Experience at Cyprus <br />mines in western Colorado indicates that this distance is from <br />0.25h to 0.4h, where h is equal to the overburden depth. Larger <br />values reflect increasing strength of the overburden strata. <br />Given the lack of strong sandstone units in the overburden above <br />Panel B in the Steven's Gulch area, a value of 0.3h is used in <br />the analyses for this study. Wilson (1982b) recommends using a <br />value of 0.3h. <br />• <br /> <br />Cyprus Orchard Valley Mine March 12, 1992 <br />Panel C Pillar Analysis page 5 <br />