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• - 14 - <br /> <br />The proposed da*~ section is shown or. Fig. 7A. The orincinal <br />features include a 3:1 upstream slcpe and 2.5:1 downatre~ slope with <br />an essentially r:bdified hoso?eneous embankment. FeRroval of some of the <br />upper soils in the center of the drainage will be necessary t~ i:~prove <br />foundation characteristics which will also allow for the steeper down- <br />strea;~ slope. Selective place,T2nt of coarse.sandstcne will be requircy? <br />at the downstream toe. Underlying the dam on the ao~.anctrcam toe will <br />be a blanket drain. The location of the drain and the overexcavation <br />are shown on Fig. 7. The upstream face •aill be protected by a rirrap <br />layer 19 incises thick. Placement of e-ha.Ncnont material ~aill rec?uire <br />benching into the natural :oils and sore dewataring in the middle of <br />• the drainage. Compaction should be to 933 +;adified Proctor density. <br />Foundation Conditions: Test Floles 29 to 33, shocm on Figs. 12 and 13, <br />show the subsoil conditions disclosed by our test holes. Ir. general, <br />the subsoil conditions are fairly similar to those retorted for the dam <br />upstream, shalla~ bedrocY. on the sides of the valley anc: about 20 feet <br />of soft to ~~edium stiff clay soils in the bottom of the valley. Ground <br />water level occurs in the alluvium overlying bedrock. A generalized <br />profile along the centerline of the enbanlc;ent is shown on Fig. 7d. <br />Consolidation tests on the soils underlyirt3 the errtbanl¢nent are <br />shown on Figs. 25 and 20. These indicate rioderate consolidation under <br />the 'proposed load. Cn Figs. 28 through 30 are shown gradation analyses <br />of the soils and bedrock. The clays contain a high nnrcerrage of fines <br />. and have a low density, high moisture content and are :moderately <br />.: <br />