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A digitizer was used to balance the cut and fill volumes of material needetl to create the above-described <br />topography. A swell factor of 15.3 percent was utilized for the adjacent and back 2 spoils based on previous • <br />studies. A swell factor of 25 percent was used for the blasted highwall. The two adjacent spoils would be <br />dozed into the open pit and the two back (furthest from the pit) spoils would be graded into the adjacent v's <br />created by the spoil (see appropdate worksheets in Attachment 13-3). <br />Highwalls will be reduced and sloped towards the open pit. This would be accomplished by drilling and <br />shooting the highwall (see Worksheets WC-4 and WA-4) and then dozing/ripping the blasted material into <br />the open pit. See Table 13-2-3, Attachment 13-2 for a wmplete listing of volumes to be dozed into the open <br />pit. <br />A Caterpillar computer program called EMF was used to determine dozer production. This program utilizes <br />information given in the Caterpillar Handbook. All tables and charts have been computerized to simulate <br />production for track type equipment. See various worksheets for production and costs. <br />The premining and postmining topography maps were compared for material movement. Although a specific <br />postmine topography map is not available fora 1994 mine closure, drainage patterns will generally remain <br />the same as the planned final topography. Due to the fad that the topographic highs and lows will generally • <br />be located in the same area after mining as they were prior to mining, it is not anticipated that wheel type <br />earthmovers will be needed to backfill the final pit. <br />Ramp grading estimates are included with spoil grading. It was assumed that ramps will be graded at the <br />same time as two spoils are pushed into the pit and, therefore, additional cost is not estimated for this <br />project. <br />Topsoil Replacement. Topsoil replacement volumes were based on the volume of material in stockpiles at <br />the end of year 1994. Tha estimated volume in each stockpile was based on topsoil salvage depth per soil <br />type over a particular area (acres). In an effort to ardve at realistic stockpile volumes, topsail densities were <br />measured in the field. According to Caterpillar, the swell factor for this type of topsoil would be around 35 <br />percent from BCY to LCY. The material density, as measured in the stockpile, was 2518 Ibs/cy. Assuming <br />this material was compacted to 90 percent of its original density, the original density would have been 2518 <br />Ibs/cy divided by .90 = 2800 IbsBCY. To ardve at the LCY density, take 2800 Ibs/BCY divided by 1.35 = <br />2075 Ibs/LCY. Table 13-2-5 is based on this density for replacement purposes. FPC printouts in <br />Attachment 13~ list the production time assoclated with each topsoil stockpile. • <br />TR-37 13.50 Revised 04/05 <br />