2015-12-03_GENERAL DOCUMENTS - M1974070 (5)

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Lined Pit Guide I 1 September 2000 3H:1 V, horizontal benches shall be excavated into the slope to allow fill to be placed in horizontal lifts and to eliminate potential weak interfaces between the fill and native ground. Embankment material shall be continuously benched and keyed into the existing material a minimum of 2 feet. Fill Placement— ✓ The distribution of materials shall be.such that the fill is free from voids, lenses, pockets, streaks, or layers of material differing substantially in texture or gradation from the surrounding material. ✓ The fill surface shall be at or near the same elevation at all times during construction; the maximum permissible difference in elevation between fill surfaces shall be 3 feet. At all times during construction, the surface of the fill shall be graded to prevent ponding of water and maintained for storm water drainage. ✓ Fill placement shall occur by routing the hauling and spreading units approximately parallel to the axis of the fill. As far as practical, hauling units shall be so routed that they do not follow in the same paths, but split their tracks evenly across the surface of the fill to enhance compaction. ✓ Water required for moisture conditioning shall be applied on the fill or in the.borrow areas using water trucks with spray bars for even distribution of water. Adjustments in moisture content shall be made principally in the borrow area. Fill materials shall be maintained within the moisture,content range required to permit proper compaction to the specified density with the equipment being used. The moisture content of the fill materials, prior to and during compaction, shall be uniform throughout each layer of the material. Mixing of wet and dry material on the fill to obtain the proper moisture content shall not be allowed— _ ✓ After each layer of fill has been placed, spread, and moisture conditioned, the layer shall be compacted by passing compaction equipment over the entire surface of the layer a sufficient number of times to obtain the required density. Prior to placement of subsequent lifts, the previous lift shall be thoroughly scarified to a depth of 2-inches to provide good bonding between lifts. Scarification shall be accomplished by discing, raking with a grader, or approved alternative method. ✓ Soil liner fill shall be placed and compacted to achieve a coefficient of permeability of less than 1x10.6 cm/sec. ✓ Compact the soil liner fill to at least 95 percent of the maximum dry density as determined by the Standard Proctor density test (ASTM D 698) at a moisture content between 1 percent below and 3 percent over the optimum moisture content. ✓ In order to resume soil liner fill placement or other operations following an occurrence of inclement weather, unsuitable material shall be removed and dried. ✓ Desiccation and crusting of the soil liner lift surface shall be avoided as much as possible. Cracked areas and swelling, heaving, or other similar conditions shall be replaced or reworked to remove such defects. I