The behavior of a dam during initial filling of its impounded reservoir, which can be characterized not only by the ascent of the water level, but also by warming of the bed of the dam and change in its physico-mechanical properties during filling of the reservoir as a result of its contact with the water, is analyzed. It is demonstrated in this period that it not so much the hydrostatic pressure of the water as the change in the temperature regime in the near-surface zone of the bed that has a major determining effect on deformation of the near-contact zone of the bed.When constructing water-development works in regions of permafrost propagation, it is necessary in the initial filling of the reservoir to consider the possibility of pronounced changes in the phsyico-mechanical characteristics of their rock beds. Serving as the basic factor for the heat transfer of positive temperatures into the rock bed of the dam, the water of the reservoir will, as a result of warming of the bed, contribute to its increased deformability, increase in porosity, and fissuring, and reduction in strength. Moreover, all this will occur over time in the process of warming, making it impossible to previously construct a geomechanical model for prediction of the behavior of the structure during initial filling of the reservoir.The first filling of the reservoir at the Boguchany HPP, when despite the increase in hydrostatic pressure on the body of the rock-fill dam, its displacements were recorded in the direction of the upper pool, and an increase in settlements was noted as the air temperature rose with the upper pool at an essentially constant level, may serve as one of the characteristic examples of such behavior [1].The rock-fill and concrete dams at the Boguchany HPP were constructed under complex natural-climatic conditions, which have exerted a considerable influence on the condition of the structural components of the dam. The maximum temperature differential at the damsite during initial filling of the reservoir was of the order of 50°C (from +20 to -30°C), just at that time when the temperature of the bed in the near-contact zone prior to start of filling of the reservoir fluctuated from +1 to +5°C.The first pronounced increase in the temperature of the bed of the dam was noted after the start of the initial filling of the reservoir on 16 April 2013 (Fig. 1); here, it was noted not immediately after the start of ascent of upper-pool level, but after approximately one month, during which warming of the near-contact zone of the bed of the concrete dam, which is comprised of a dense dolerite, was initiated. Temperatures of the bed were measured by PTS-60 string temperature transducers in holes. Figure 2 shows diagrams of the temperature rise in the bed of Section No. 14 of the concrete dam and the concurrent increase in its settlement. It is obvious that penetration of reservoir water into the bed of the dam had caused the temperature to rise in its near-contact zone, exerting a significant influence on the behavior of the concr...

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Results of investigations of the earthquake resistance of structures are analyzed.The detailed design of the Boguchany HPP was developed in the 1990s when the seismicity of the region was evaluated at six points. The stress-strain state (SSS) of the basic structures had not been analyzed for a six-point seismic event in conformity with Construction Rule and Regulation II-59-74 "Riparian water-development works. Basic design positions," which was in force at that time.In 1999, the seismicity at the construction site of the Boguchany HPP was elevated, and is currently seven points with a repeatability of once every 5000 years (I norm = 7) according to the OSR-97-S map in Construction Rule and Regulation II-7-81* "Construction in seismic regions" [5].In 2000 -2002, the Center for Geodynamic Observations in the Power-Generation Industry (CGOPGI), Institute of the Earth's Crust, Siberian Division of the Russian Academy of Sciences (IEC SD RAS), and the Altai-Sayano Experimental and Seismological Party (EMSP) conducted seismological investigations in the area of the hydroproject's construction. As a result of the investigations, the level of the design intensity of earthquakes for the region of the Boguchany HPP was established at six points (I in = 6) based on the OSR-97-S map (i.e., with a design period of repeatability of the maximum design earthquake (MDE) of once in 5000 years), and up to five points based on the OSR-97-C map (with a design period of repeatability of the design earthquake (DE) of once in 1000 years) [7].According to the "Design rules for water-development works in seismic regions" [2], Construction Rule and Regulation II-7-81* "Construction in seismic regions" [5], and Construction Rule and Regulation 33-03 "Water-development works in seismic regions" [6], water-development works are not subject to analysis of seismic loads in a region with a six-point seismicity.In various organizations of the Krasnoyarsk Kray, doubts have been voiced concerning grounds for substantiation of the lowering of the level of the design seismicity, and, accordingly, the earthquake resistance of basic structures of the Boguchany HPP. To put these doubts to rest, the staff responsible for the construction charged the Institute Gidroproekt to conduct verification studies of the earthquake resistance of the concrete and rockfill dam (RFD), powerhouse, and service and production building (SPB) under an assigned seven-point seismicity (I in = 7). (Candidates of Technical Sciences A. V. Deineko and D. A. Krutov, and engineers L. D. Solov'eva and A. A. Yakushev participated in the studies).To utilize the design positions stated in Rules [2], and Construction Rules and Regulations [5] and [6], we conditionally worsened the seismic conditions at the construction site by a factor of two:-increased the initial seismicity from six to seven points (I in = 7) with a design period of once in 5,000 years; and, -lowered the class of the soils in the bed of the structures at the Boguchany HPP from Class I to Class I -II.The maximum peak ...

A design is proposed for a stepped spillway.A detailed design of the Boguchany HPP with a rated capacity of 3000 MW (nine generating sets each with a capacity of 330,000 kW and a reservoir at elevation 208 m was approved in 1979 by order of the Council of Ministers of the USSR in an agreement reached with the State Committee on Construction. In 1982, the first cubic meter of concrete was placed in the basic structures of the hydroproject. From 1993 through 2005, construction proceeded at extremely low rates on structures of the hydroproject. After the decision was made to resume construction on the BoHPP in 2006, the institute Gidroproekt (Moscow) was commissioned to render a partial adjustment to technical solutions of the 1979 design. Basic premises for partial revision of the technical solutions were:-a change in basic positions of the regulatory base for the design of water-development works;-a deficiency of carrying capacity of the spillway structures at the hydroproject in periods of permanent and temporary service; and, -the need to ensure operational reliability of the spillway structures, and the possibility of performing their running repairs.Agricultural and water-power analyses performed in compliance with requirements of the Construction Rules and Regulations indicated that the carrying capacity of the hydroproject in the periods of temporary and permanent service is lower than that required for passage of the spring flood and high water of the summer and fall. To retain the design values for the maximum water level in the upper pool, and ensure reliable passage of flows into the lower pool, it was necessary to increase the carrying capacity of the hydroproject by installing a second spillway (No. 2) in addition to the existing and partially constructed No. 1 spillway.In the design, the No. 2 spillway is to be placed in the segment containing the unfinished No. 20 -22 sections of the concrete dam alongside the partially constructed No. 1 spillway using the pit opened for resumed construction of generating sets No. 10 -12 of the powerhouse (a decision to cancel construction of these sets was made after the pit had been opened). Three alternate construction schemes of the No. 2, spillway, which are distinguished one from the other primarily by the method used to dissipate the energy of the discharge flow, are called for in the design. In two of the alternate schemes, it is specified that the energy of the flow be dissipated in a tow basin, and a scheme whereby the flow is discharged into the lower pool beyond the limits of the structures being erected is called for in the third.In hydrotechnical construction, problems associated with effective dissipation of excess flow energy, and erosion control of the surface of the water-passing structures determine their design for the most part. Preliminary analysis indicated that the installation of a stepped overflow face for the No. 2 spillway will ensure: -operation of the spillway in a cavitation-free regime by reducing the velocities of the flow, and its vi...

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