Basic directions in the improvement of hydropower construction techniques

Abstract

Over the years of the Soviet regime, hydropower has grown from the stage of the firstlings of hydropower construction, such as the V. I. Lenin-Volkhov, Boz-Sui, and Zemo-Avchalsk plants, to the unique hydraulic developments of the present time, which have the world's highest dams: the embankment dam of the Nurek plant, and the concrete arch dam of the Inguri plant. This became possible thanks to the development of new methods of structural analysis using electronic computers, introduction of modern, highly efficient methods of construction, and extensive experience acquired during construction of large Soviet hydraulic developments, both on plains rivers with soft foundations and on mountain rivers.It is especially important to point out the advanced experience acquired from year-round construction in the Far North and permafrost regions.At the present time, concrete is being placed over a wide front at the startup construction projects of the Tenth Five-Year Plan --the Sayano-Shushenskoe and Inguri hydroelectric plants. Also, construction is being started on the Kolyma, Kurpsa, Rogun, Bureya, and Boguchany hydroelectric plants, most of which are of the multipurpose type, as well as on the Zagorsk and Kaishyadoris pumped-storage plants. Along with improvement of the constructional solutions for the main structures, in the near future the basic trend in the improvement of hydrop0wer construction will continue to lie in the introduction of better methods of building them.A significant share in the improvement of the effectiveness of construction work lies in the reduction of labor costs. Thanks to the use of integrated mechanization, a high labor productivity has been achieved at several construction projects.At the massive Toktogul dam a method was worked out and introduced for layer-by-layer placement of concrete in large blocks by applying a special, fully mechanized technique which makes it possible to increase the concreting labor productivity to 11-13 mS/man-day as against the previously achieved figure of 4-5 mS/man-day.At the Chirkey arch dam, through delivery of the concrete by 25-ton cableways and use of integrated mechanization the labor productivity was brought up to 10-11 mS/man-day.The use of heated forms, tents, and various other measures made it possible to place concrete during an entire cold winter in the Ust-llim and Zeya dams. The successful construction of hydraulic developments in the Far North regions has been considerably aided by the new methods of year-round construction of embankment dams, developed by the Gidroproekt Institute jointly with the constructors, which have made it possible to successfully build the impervious elements of the Vilyui, Ust-Khantaika, and Serebryansk dams during the winter. Still wider possibilities for construction of hydraulic developments on large rivers have been offered by the passing of flows during construction over the uncompleted rock--earth Ust-Khantaika dam. A new improved technology made it possible to achieve great successes in the construction of th...