Interaction of Waves with a Loose Bank Slope
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Vol. 54, No. 4, November, 2020
INTERACTION OF WAVES WITH A LOOSE BANK SLOPE A. V. Ostyakova1 Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 5, May 2020, pp. 30 – 35.
Expressions for the surge and swash heights on the loose sloping bank of a reservoir, the swash velocity for a wind wave, the maximum bottom velocity, and the pressure on the loose bank are presented. Based on studies by different authors, the pressure distribution over the slope, the nonstationarity of the flow resistance, the transport rate of suspended and stream sediments are assessed experimentally. Keywords: bank transformation; bank stability; surge height; wave pressure on bank slope; unsteady flow resistance; sediment transport.
abroad. There are models and procedures for analysis of the hydrology, thermal and ice conditions of reservoirs, models of the dynamics of ice-covered flows, the dynamics of nonfreezing and sea shores [1, 2] based on mathematical and physical modeling. A few full-scale observations of the transformation of banks caused by wind waves are complicated. There are results of such observations, but they are mainly qualitative. The analysis of bank transformation depending on the effect of waves is based on the statistical processing of available records over 30 to 100 years, which do not often include the last two or three decades during which the climate has undergone an intensive change. Laboratory studies of the complex, multifactore mechanism of the effect wind waves exert on loose banks are few [3] and often disregard some factors. Factors Affecting the Stability and Causing the Collapse of Reservoir Bank Slopes Subject to Wave Action. A change in the hydrological regime of a river or a reservoir is closely related to the transformation of its loose bank slope, while a change of the bank condition, in turn, affects the hydraulic and hydrological regime of the reservoir bed, banks, and adjacent areas. Mutual changes in reservoirs, as well as in rivers, are caused by factors of different nature and strength. Bank transformation is caused by the following factors [4, 5]: — level fluctuations of different nature, such as regime phenomena, floods, surges, seiches, wind waves, ship-generated waves, and storm waves; — erosion caused by currents of different nature; — ice processes, intensive thermal abrasion; — the geological structure of banks, including the fineness and inhomogeneity of the soil of bank slopes, bank vegetation, the ingressiveness of banks of various soils;
The climate changes and increased man-induced impact on the environment in the last decades have increased the risk of catastrophic phenomena and accidents in thawing permafrost regions, including banks. Almost half of the emergency situations (48%) results from changes in the hydrological conditions of water bodies caused by bank transformation, anomalous bank deformations, collapse/silting of banks, and deterioration of navigation and operation of hydraulic structures. Therefore, it is important to study the dynamics of the bank slopes of rive
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