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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 />inch thick downstream shotcrete face is to help prevent further temperature <br />deterioration, and to complete the new composite arch. Bolts protruding through <br />the downstream shotcrete will act to bond it to the existing dam. <br />Grouting <br />The dam would be grouted from the crest through vertical holes drilled at <br />least five feet into the foundation rock. Primary holes will be drilled and <br />grouted on ten-foot centers. A secondary row of holes, splitting the spacing of <br />the primary holes, would be drilled and grouted on ten-foot centers. Tertiary <br />holes would be drilled and grouted as necessary. We envision a total of 40 <br />holes and 1,400 linear feet of grout holes. Selected holes would be cored and <br />selected cores tested to gather information on concrete conditions before, <br />during, and after grouting. <br />We envision the use of a thick cement grout (one to one ratio of water to <br />cement by volume) and low pressures (about 1/2 psi per foot depth). Grouting <br />would be performed contemporaneously with shotcreting. Grouting will fill any <br />internal voids, cracks or poorly cemented zones. Grouting will increase the dam <br />mass, reduce stress concentrations in the dam by making the concrete more homo- <br />genous, and decrease the dam permeability, especially at the dam-rock interface. <br />Tensi oned Bolts <br />We envision a total of 140 one-inch diameter, continously threaded, No.8 <br />bolts with bearing plates, and nuts placed throughout the dam. These would be <br />placed in a staggered pattern of 8-foot horizontal centers and 4-foot vertical <br />centers. The bolts would be angled at 450 from horizontal and 450 from radial <br />arch lines. In general, the bolts will be angled towards the right abutment <br />when placed right of the dam maximum section and towards the left abutments when <br />placed left of the dam maximum section. The bolts will be fully grouted with <br />cement and tensioned after placement of eight inches of shotcrete on the <br />upstream face and four inches of shot crete on the downstream face. After ten- <br /> <br />-26- <br /> <br />".~:',.,;~,;/' <br />- . <br />::..:~.. '.. <br />; '. ~ *'.~~~~\}: f'"; <br /> <br />." <br />