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<br />I <br />, <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />J <br />I <br />I <br />I <br />I <br />I <br />I <br />~ <br /> <br />I <br />I <br /> <br />serious nature of the seepage condit Ion. Although the total seepage loss fs <br />not critical to the economical operation of the reservoir, seepage fs a <br />serious concern from the standpoint of dam safety. <br /> <br />Inspection of the outlet works and wet well showed them to be In fair <br />condition. A few Inches of sand and gravel covering the conduit Invert, minor <br />cracks, pin-hole seeps, and minor erosion of the concrete at construction <br />joints were the main defects noted. Patching of surface defects over the <br />years seems to have been effective, with no evidence of deterioration. The <br />tlet well was In good shape with the exception of a cold joint about 15 feet <br />above the Invert where seepage was evident. The bottom of the wet well was <br />full of sand and gravel, with cobbles having been deposited In the recess for <br />the steel guides of the slide gate, nlaklng It Impossible to close the gate. <br /> <br />Inspection of the auxiliary spillway and dike revealed them to be In goorl <br />condition. The rlprap protection In the overflow section, however, appeared <br />to be too small, and the downstream slope too steep to resl st erosion from the <br />desl gn fl Oil durl ng overtoppl ng. <br /> <br />A geotechnical investigation tlas conducted In the field and laboratory to <br />evaluate the materials that comprise the dam, foundation, and reservoir. The <br />resul ts of this evaluation were Input Into stability and seepage analysis, and <br />were utilized to assess the properties of the local materials In order to <br />formulate alternatives for rehabilitation of the observed deficiencies. <br /> <br />The field work consisted of surficial geologic mapping and subsurface <br />exploration by four rotary boreholes, 13 test pits, and 1150 11near feet of <br />seismic refraction survey. Field tests of permeability, penetration <br />resistance, and In-place density were performed In the boreholes and test <br />pits. laboratory testing of samples obtained from the boreholes and test pits <br />consisted of visual classification, sieve analysis, plasticity <br />characterl za tl on, shear strength, and permeabl 11 ty. In addition, tes ts for <br />durability were performed on samples of material with potential as concrete <br />aggregate. A trial mix of roller compacted concrete was also prepared and <br />tested. <br /> <br />Iv <br />