| Popis: |
Improving methods and technologies for calculating and designing floodplain transverse dams, taking into account the interaction of floodplain and riverbed flows to protect the banks from erosion and regulate riverbeds is one of the most important tasks. At the same time, the priority remains the transverse blind dams made of local soil with the attachment of their head. Their construction on rivers with two-sided asymmetric floodplains has its own characteristics, which consist in the need to take into account the morphology, the different roughness of the floodplain and the channel, the interaction of floodplain and channel flows, the asymmetry of the constraint. The physical picture of flow spreading was established on the basis of experimental studies carried out on a model 11 m long, channel width 30 cm, floodplain width 42.5 cm and 85 cm. and downstream whirlpools, asymmetric spreading of the flow behind a compressed section of different lengths. The distribution of velocities in the interaction zones and zones of intense turbulent movement, and in this case, obey the theoretical Schlichting–Abramovich relationships. The planned dimensions in the spreading area are established theoretically by applying an integral relation that characterizes the law of conservation of momentum in the flow recorded separately for the left and right floodplains. Dependences are proposed for determining the length of the whirlpool zones behind the compressed section and , which depend on the parameters of the channel and the floodplain of the zones of interaction between channel and floodplain flows. A comparison of the calculated and experimental data shows their satisfactory matches. The difference does not exceed 5%. |
