2009-11-13_PERMIT FILE - C1982056 (3)

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• The sub -base and road base materials should be compacted to a minimum of 95 percent of the maximum modified Proctor density, as determined by ASTM D 1556. We recommend that the roadway areas be prepared by scarifying, moisture conditioning and re- compacting the existing soils to provide uniform support for the roadway section and help control differential movement. We recommend that the subgrade areas be scarified to a depth of at least 12 inches; the exposed materials be moisture conditioned by bringing the scarified soils to within +/ -2 percent of the optimum moisture content; and then recompact the properly moisture treated soils to at least 95% of the maximum standard Proctor density determined in accordance with ASTM D698. After the subgrade soils have been properly moisture treated and recompacted, the subgrade should be proof rolled with a heavily loaded pneumatic tired vehicle and any areas which deform excessively under the wheel loads should be removed and replaced or stabilized prior to paving operations. Areas of soft and saturated soils may be encountered near subgrade elevations in some areas. Removal and replacement of these materials may be required and should be evaluated at the time of construction. Any additional fill materials placed under the pavement areas should be uniformly placed and compacted in 6 to 8 inch loose lifts to at least 95 percent of the maximum standard Proctor density and within +/- 3 percent of the optimum moisture content. The materials removed from cut areas can be used for subgrade fill materials, after any boulder sized fragments are removed. Drainage ditches will be constructed along the new haul road to provide drainage away from the road section. Approximate locations of the culverts to be installed across the new haul road are presented in Figure C -103 and may have to be modified at the time of construction. Culvert sizes are shown on Figure C -103 and outlined in the Surface Water Management Plan. The road base materials should be shaped to drain away from the roadway to the drainage ditches. Drain Construction The underdrain location is shown in Figure C -101 and typical cross - sections and material requirements are presented in Figure C -301. The drain materials will not require compaction. The drain materials can be loose dumped to the minimum dimensions shown. The drain materials should be protected from excessive contamination by the use of two layers of filter materials. The filter materials must meet the specifications noted and be constructed to the minimum thickness shown in the cross - sections. Coal Waste Placement and Compaction Regulation 4.10.4.3 require the coal refuse materials be placed in lifts of 24 inches maximum and be compacted to a minimum of 90 percent of the maximum dry density as determined by AASHTO T -99. However, we recommend that the coal refuse materials be placed in lifts of 12 inches or less and be compacted to a minimum of 90 percent of the maximum Standard Proctor density, within 3 percent of the optimum moisture content, as determined by AASHTO T -99 /ASTM D698. • Job Number: 08 -7915 NWCC, Inc. Page 9 Revised 10/12/09