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The experience of carrying out grouting works during construction of high concrete dams attests to a substantial change in the stress state of adjacent columns under the effect of a comparatively small pressure on the surface of the joint between the columns [1]. In this connection the authors as early as the stage of working out the specifications for suppressing seepage through the stretched zone of concrete of the Sayano-Shushenskoe hydrostation dam gave special attention to possible consequences (positive and negative) of injecting grouts into seeping cracks at pressures considerably greater than those observed during grouting of the joints between columns and sections of the same Sayano-Shushenskoe dam during its construction. The firm approved to carry out the grouting works was supposed to inject comparatively viscous grouts of the "Rodur" type, as on other objects in past years, at a pressure exceeding 40 MPa at the pump outlet, which rapidly dropped on advancing along the injection path with a length of 15-20 m and at the mouth of the crack varied within 6-8 MPa with a 3 x 3-m arrangement of the holes and delivery of the polymer material through two holes. Only such a pressure made it possible to provide high-quality and continuous filling of the cracks with grout even with a small opening.During approval of the specifications specialists of the firm asserted that the effect of the grout pressure was limited to a small zone near the hole and additional opening of the cracks would not exceed the compressive strains from the unique press plate, which in cross sections with through cracks usually did not exceed 1 mm.Different regularities of additional opening of cracks that partially disturbed continuity of a cross section about 80 m high to a depth of 15-17 m ought to be expected in the particular case of grouting. The more so as grouting was to be done at upper pool levels (UPLs) close to the normal pool level (NPL), when the cracks without additional interference were in an equilibrium state.In the first years of normal operation it was established during drilling of exploratory holes and inspecting the walls by means of TV cameras that cracks were prevalent in the mass in the form of numerous small disturbance of the solidity of the concrete in zones 1.5-5.6 m high. Exploratory drilling before the start of grouting in 1996 showed the presence in each section of one to three zones with several cracks with a comparatively small opening. According to the readings of long-base deformometers, the openings of the cracks immediately before the start of industrial grouting at an UPL close to elevation 540 m were from 0.33 to 0.98 mm. At the dead storage level all cracks were practically closed. A plan was drawn up for grouting 40 zones in 24 sections to fill the main and small, intensely seeping cracks with grout into the depths of the mass. During grouting one could not assume penetration of cracks into the depths of the mass of the dam in connection with the fact that calculations established a zone of tensi...

The Sayano-Shushenskoe hydroelectric station is a unique, in size and complexity of construction, hydropower structure on the Enisei River and is part of the Sayan hydropower complex, which also includes the counter-regulatlng Maine hydropower development. The hydrostation will become the power base of the developing Sayan territorial industrial complex.Construction of the Sayano-Shushenskoe hydrostation required the large-scale organization of research and development 4nsuring the creation of reliable, economical, and operationally convenient structures and equipment. The complexity of the problem necessitated a broad approach to the solution of scientific--technical problems arising during design and construction of the hydrostation and manufacturing its equipment. An important place in the organizational and technical solution of this problem is being played by a new mass form of socialist competition--an agreement on creative scientific--technical collaboration among Leningrad organizations participating in the creation of the Sayano-Shushenskoe hydrostation, which is aimed at the most rapid solution of scientific--technical problema and their introduction into production. The main purpose of the agreement is to shorten the construction time of the station with a high quality of work by accelerating the start-up of its units, reducing the consumption of materials and cost of construction, creating the latest equipment, and improving construction technology.This initiative of the Leningraders, supported by the station's builders, was approved and recommended for wide introduction by the Central Committee of the CPSU and highly praised by its General Secretary, Comrade L. I. Brezhnev. "The Agreement of the 28" became the progenitor of a new form of interbranch organization of the combined development and creation of large national-economic installations.The Sayano-Shushenskoe project includes a gravity-arch dam more than 240 m high with a crest length of 1066 m, containing about 8.5 million m s of concrete; flood works intended for a discharge of 13,500 m3/sec; hydroelectric station with a total installed capacity of 6400 MW with i0 units capable of developing up to 720 MW each at heads greater than the designed; 500-kW outdoor electrical equipment.The Sayan reservoir, with a volume of 31 billion m s, will extend 300 km upstream and will cover a series of rapids in the river. The vast power potentialities of the Sayano-Shushenskoe hydrostation due to the 15 billion-m s drawdowuprism predetermines its leading role in the integrated power system of Siberia as a daily and annual regulator of power withan ample reserve. Creation of the Sayan reservoir will make possible water transport of freight and passengers in the Tuva ASSK. In the future, after constructing a ship lift, through navigation on the upper Enisei from Krasnoyarsk to Kyzyl will be possible.The station, regulating flood discharges, will greatly reduce flood damages. In order to ensure operation of the Sayano-Shushenskoe hydrostation to cover the wint...

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