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Sri <br />The material shall be placed in the embankment in <br />layers not exceeding six inches thick and layers shall be <br />horizontal in the direction of the axis of the embankment <br />and slope slightly downward from the boundaries toward the <br />center line. The placing of layers shall begin in the lower <br />part of the foundation and layers gradually lengthened out <br />in filling in the lower portions of the embankment. If it <br />is found that layers thicker than 6 inches can be readily <br />compacted, the engineer may instruct in writing that <br />thicker layers may be used. <br />The earth shall be moist enough to compact well but <br />not too wet. Lefore any layer is placed, the surface ahead <br />of it shall be wet but not muddy; and the layer when rolled <br />shall be moist enough to pack thoroughly. care must be <br />exercisers to see that a thorough bond is made between <br />successive layers. <br />Each layer must be kept in a moistened condition <br />until compacted. Should any layer become too hard on the <br />surface to thoroughly bond with the succeeding layer, it <br />shall be scarified. <br />Proper moisture and compaction shall be checked by <br />laboratory tests using the modified Proctor method for <br />90% compaction. <br />. Each layer shall be sprinkled, pulverized by <br />harrowing if necessary, and then rolled with a sheep <br />foot, power driven, roller of not less than 50 lbs. per <br />square inch pressure with penetration of the projections. <br />Variations in the pressure up to the amount required for <br />proper compaction shall be accomplished ?,y adding weight <br />to the roller. Rolling shall be in the direction parallel <br />with the axis of the embankment. After each test the <br />number of passes of the roller shall be fixed. <br />Such portions of the embankment as are inaccessible <br />to the roller shall be thoroughly compacted by ramming with.- <br />power driven tampers. This applies-especially to the areas' <br />under and around pipes and the filling of pipe trenches and <br />against any other structures. Any layers, streaks or <br />pockets of sand or undesirable material shall be-carefully <br />avoided. <br />At the time of completing the embankment, the outer <br />slope shall be covered with one foot thickness of soil and <br />shaped up ready for seeding as directed by the Lngineer. <br />The top of the embankment shall slope to drain toward the <br />downstream side. <br />.The intent of these specifications is to procure a <br />homogeneous, compact, water tight embankment, and it is <br />believed that the methods specified herein.will give the <br />E. <br />R