The aim of research was dam subsidence assessment of Magnitogorsk hydraulic waterworks on the river Ural Chelyabinsk region as well as time stabilization determination of its body and foundation based on long-term observations. In the process of research using a systematic approach, data of field observations carried out from December 1938 (before Magnitogorsk waterworks structures were launched) till September 2016 were analyzed. To monitor the dam subsidence consisting of earth-and-rockfill and concrete gravity parts, 14 benchmarks-makes and two benchmarks in landfalls were set on the crest. Lately H-05 level and a set of inventory three-meter rails were used. Benchmaking survey was carried out once in two years. Elevations points of working (deformation) benchmarks, located on the hydroelectric dam, were determined by the method of leveling class III. The period of body and base stabilization as well as quantitative subsidence data by year were found out. The subsidence process occurs mainly in the area of earth-and-rockfill dam by consolidation body structure. The subsidence of the dam body was 71 years, as a whole for the operation period (77 years) maximum subsidence was 342 mm, which is considerably higher than for other known dams listed in the work. At the same time the vertical deformation of the concrete part of the dam is 2.0 mm, which is within the similar values of the known concrete structures.
Keywords: vertical dam deformation, body and base of dam, earth-and-rockfill dam, concrete dam, field studies, subsidence stabilization, subsidence assessment.
