Formation of the stress-strain state of the dam at the Sayano-Shushenskaya HPP during 2010 filling of reservoir

Abstract

Translated from Gidrotekhnicheskoe Stroitel 'stvo, No. 4, April 2011, pp. 2 -6. Results of intentional action on the temperature field of the dam, which had been supercooled during the winter of 2009/10, to improve its stress-strain state by regulation of the reservoir-filling regime, are presented.The Sayano-Shushenskii hydroproject is situated on the Yenisei River. Its component parts include an arch-gravity dam with a height of 242 m, crest length (at elevation 542 m) of 1074 m, and width of 105 m along the base, and a neardam type of powerhouse containing ten hydraulic generating sets. As a result of the technogenic emergency that had occurred August 17, 2009, all generating sets had been taken out of service. In the post-emergency period, the temperature regime of the dam differed appreciably from the usual regime, particularly after the severe winter of 2009/10 [1, 2].During the reservoir's filling in 2010, the "dam -bed" system was operated in an unscheduled mode characterized by continuous operation of the service spillway (sections 38 -48), and by a dry water-supply run in seven of the 10 hydraulic turbines, including their penstocks that extended outward onto the downstream face of the even-numbered sections of the powerhouse dam (sections 16 -36).By 1 May 2010, the reservoir had been drained to a minimum elevation of 499.99 m. At that time, the stress-strain state of the dam, which had been supercooled during the winter of 2009/10, was characterized by additional displacements and inclines of the dam toward the tailrace. The deflections at the crest of the dam exceeded the 2009 values by up to 9 mm, and the turn angles within the limits of the repaired zone of the thrust face (elevation 344 -359 m) up to 3.4 sec (Fig. 1). The stress-strain state of the supercooled dam with a reduced design modulus imposed a number of requirements regarding the reservoir's filling regime. The following were recommended for its warming:-intake flow rates of up to 2700 m 3 /sec were to be passed through the structure with the upper-pool level retained at elevation 500 m;-flows exceeding 2700 m 3 /sec were to be passed with the upper-pool level maintained at elevation 507.3 m until 1 June; and,-an upper-pool elevation of 533 m be attained no earlier than 1 July.It was recommended that the maximum level of the upper pool be established with consideration that normal operation of four generating sets at the Sayano-Shushenskaya HPP (GS-3 was scheduled to be placed under load in December 2010), and the three generating sets at the Main hydroproject be ensured, and also with the consideration that water usage in population centers situated downstream on the Yenisei River be limited to an upper-pool elevation of 537.5 m.In 2010, the reservoir-filling regime was defined by characteristics of the hydrologic regime of the Yenisei River, and by regulation of idle drawdowns into the tailrace with

On Providing an Assessment Monitoring System for Especially Essential Structures

“…Monitoring the condition of such buildings and structures was provided by systems that were installed during construction. But over time, these systems partially failed [4] or became obsolete. This situation reduces the monitoring system reliability and may lead to delayed response during emergencies.…”