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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />Natural density and moisture content tests, together with standard Proctor <br />moisture-density relationships, Indicate the in-place density of the original <br />embankment is approximately 90 pe~cent of the standard Proctor maximum <br />density. Thi s i ndi cates poor compacti on, whi ch is consi stent wi th the SPT <br />values obtained from the bore hole explorations. In-place density tests of <br />the materi a1 added to the downstream toe in 1972 show it to be only about 85 <br />percent of maximum densi ty i ndicati"g it was not compacted at the time of <br />constructi on. <br /> <br />Shear strength values of the dam materials were obtained using consolidated - <br />undrained triaxial compression tests. The tests indicated high effective <br />angl es of internal fri cti on from 39 to 44 degrees wi th mi nimal cohesi on. <br />These values appeared reasonable for the material tested, but probably do not <br />represent the dam as a whol e si nce the boreho1 es reveal ed thi n 1 ayers of <br />fi ne-grai ned materi a1 that woul d have lower strength. The coeffi ci ent of <br />permeabil ity of embankment samples ranged from 10-5 to 10-7 cm/sec; The <br />materi a1 used in 1972 to f1 atten thE! downstream slope and supposedly provi de <br />drainage yielded a lower permeability value than the original dam materials. <br /> <br />Potenti al rE!servoi r borrow area materi a1 s for use as concrete aggregate, <br />impervious material, and shell material were generally classified as clayey <br />sand with gravel, with the clay typically comprising 10 to 20 percent of the <br />material. The material had a high compacted dry density, well-graded grain <br />size distribution, and low coefficient of permeability, all favorable <br />character; stics for a strong and semipervious to impervious fill material, <br />strong shell zone, or soil cement aggregate. <br /> <br />Concrete aggregate quality testing of the material indicated satisfactory <br />properties, with good specific g~avity. absorption, and sodium sulfate <br />soundness values, and marginal Los Angeles abrasion and organics test <br />results. A roller compacted concrete (RCC) trial mix was prepared using the <br />borrow area material. After proceSSing to meet the recommended RCC gradation <br />band, si x test cy1 i nders were cast usi ng a cement content of 150 1 b/cy. <br />Compressi ve strength tests were schedu1 ed for 7, 28, and 56 days; Strength <br />test resul ts to date are encouragl ng comparab1 e wi th other materi al s tested <br />and used for RCC by MKE on past projects. <br /> <br />-49- <br />