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<br />~t.:.c.:.~~~,"_,,-..C'-'-'_~"-'-'-C_~'~_""''--'-'-~C.-'~-''_'-:i:'-',C,C..:.__.,...C_"-',..-'-C."-_.._~... ....~,.---""~::;;.=;=- <br /> <br /> <br />, ( ') -- <br /> <br />seepage analyses shall be carried out for the feasibility design on each <br />Project. The stability evaluation shall be performed for steady state, <br />seismic and rapid drawdown loading COnditions. <br /> <br />Computerized stability programs shall be used that emPloy the modified Bishop <br />method. These programs provide a search for the most critical circle for the <br />conditions selected. Variables of embankment and foundation strengths, <br />seepage flow lines, draw down conditions, and seismic loads shall be selected <br />and incorporated into the stabi 1 i ty computati ons duri ng the process of refi n- <br />ing the prelimina~ designs on the selected alternative for each Project. The <br />same type of computational process shall be used in less detailed scope to <br />provide guidelines and evaluation data for the initial alternatives pre- <br />sented. The geotechnical analyses shall also consider the future needs for <br />instl"Ulllentation or measuring devices to monitor performance after rehabilita- <br />tion. Roller Compacted Concrete (ReC) may be a viable tool for constl"llcting <br />auxi1ia~ spillways to meet design flood requirements at one or more of the <br />sites. Therefore, MJ<E shall make a field reconnaissance of potential con- <br />stl"llction materials during the taSk 2 site visit and select one or more <br />sources for sampl ing of potential RCC aggregate at each site. The samples <br />shall be subjected to a batte~ of laborato~ tests as specified in Section <br />7.2.4 of this Document' to determine their physical characteristics. In <br />addition, at least one trial RCC l1lix shall be made and cylinders cast for <br />determination of compressive streng~. and' freeze-thaw durability. <br /> <br />The following ;s a site by site dE!scription of the geotechnical exploration <br />program for each of the three dams. <br /> <br />7.2.1 Comanche Dam <br />Over the years a total of 19 bore holes have been drilled through the dam and <br />downstream of the dam. While these holes have described the material encoun- <br />tered in the embankment and foundation, ve~ few samples were taken, and the <br />laborato~ testing performed on theSe samples did not correspond to the visual <br />description. In addition, no in-I)lace permeability tests of the dam and <br /> <br />-8- <br />