Laserfiche WebLink
<br /> <br /> <br />1. Soils investigation to determine the characteristics of <br />the core material in the dam. This will require test <br />holes and laboratory anaIysis of the existing core materiaI. <br />It will include such items as triaxial shear tests, plastic <br />limits, gradation and soils classifications, porosity and <br />other pertinent soils data. <br /> <br />2. Survey data on crest and toe to establish, if possible, the <br />degree of movement. <br /> <br />3. Hydrological analysis on the watershed to determine adequacy <br />of the spillway. <br /> <br />4. Inspection of the outlet tube to determine structural adequacy. <br />Only the downstream portion to be inspected at this time. <br /> <br />S. DeveIop alternative designs for the repair of the dam to include: <br />spillway, embankment, and outlet works. <br /> <br />6. Develop a cost effective analysis to determine the most feasible <br />solution to the existing conditions, i. e. , a) Iower maximum water <br />level and increase spillway; b) retain maximum water level and <br />improve spillway; c) eliminate dam and storage to a much smaller <br />storage facility, or d) some combination of the above. <br /> <br />FieId data was gathered for soils, hydrology, and surveyed <br />sections . <br /> <br />S u rve y <br /> <br />Centerline stationing and cross sections were obtained of the dam. <br />This data is presented on Sheet 2 and Sheet 3 of the drawings. On Sheet 2 <br />the cross sections indicate subsidence of the downstream face localized in <br />two areas, the same areas where high seepage flows occur. During the <br />survey, two spots were found where trickling water could be heard within <br />the downstream rock slope. These locations are at Stations 1 + 92 and <br />6 + 37 and exist in the major subsidence areas of the downstream face. <br />Both areas were observed frequently through the summer and at different <br />levels of water storage. At high water levels, levelS equaI to spillway <br />eIevation, the cascading sounds were strong; at levels six (6) feet below the <br />spillway the cascading sound diminished to a hard to ascertain noise, but <br />still existing. <br /> <br />The cross sections tended to verify the upstream and downstream <br />slopes as presented on the archive drawings. The centerline of the dam <br />does not match the archive drawings in either dam length, alignment or <br />Iocation of spillway. However, Iength of dam and spillway location do not <br />materially effect this anaIysis, but do illustrate variation from design to <br />as-built conditions. <br /> <br /> <br />IlI-2 <br />