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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 />,-- <br /> <br />Temperature Studies <br />The concrete temperature has a significant effect on the concrete stress <br />in an arch dam and thus there are three possible inputs for temperature loading <br />which include: 1) Uniform temperature across the arch, 2) Linear temperature <br />change across the arch, and 3) Linear temperature change across the arch and <br />variation of this along the length of the arch. In this study is was assumed <br />that there would be a uniform temperature across the arch; however, the tem- <br />perature will vary for each arch. Temperature studies were performed on the dam <br />using U.S. Bureau of Reclamation procedures (Townsend 1965) which have been <br />adapted into a computer program called OS HEAT. The data required for the ana- <br />lyses are the average air and water temperatures over the period of a year, the <br />dam grouting temperature and diffusivity of the concrete. Diffusivity is an <br />index of the facility of the concrete to undergo temperature change. <br />The program determines the concrete temperatures at points across each <br />arch section over a specified time interval and a number of yearly cycles. In <br />this analysis the program determined temperature effects for a three-year cycle <br />and concrete temperatures across each arch were printed out at six-day inter- <br />vals. The yearly maximum and minimum average concrete temperatures obtained <br />from this analysis were used in the ADSAS program. Baseline air temperatures <br />were obtained from the Allenspark, Colorado weather station modified for dif- <br />ferences of elevation at the Bluebird Dam site. Water temperature estimates <br />were obtained from the Grand lake weather station modified for differences in <br />the air temperatures at the two sites. <br />Two temperature studies were conducted, one study for the existing dam <br />and another study for the rehabilitated section. In summary, results of the <br />temperature study for the repaired dam cross section indicated that the minimum <br />concrete temperatures would be a critical period for temperature induced tensile <br />stresses and that these minimum temperatures would occur on approximately <br />-16- <br />