Over the last hundred years, shaft spillways have become widely used in hydraulic engineering practice due to their undeniable advantages: high discharge capacity, maximal water consumption per one cubic meter of concrete, point structure compactness. The modern theory of hydraulic calculations was formed based on works on the study of the operation of a circular spillway with a sharp edge carried out by Wagner in 1954. Although numerous hydraulic studies have not proved many of the statements Wagner's calculation methodology was based on, the materials of his studies have been presented in special hydraulic literature for hydraulic calculations up to date. The accepted design conditions of the drainage surface of the spillway shaft, which is round-cylindrical in the cross-section and in the form of a convex parabolic line in the longitudinal section, do not correspond to the possibilities of work. As a result, the drainage surface is replaced by a system of truncated cones, the joints of which cause flow separation from the drainage surface and the formation of vacuum zones. It results in approximate hydraulic calculations. To eliminate these disadvantages of hydraulic calculations and bring design developments in line with technological possibilities of works, it is possible to replace a round-cylindrical cross-section of the inner surface of the shaft with a polygonal one. In this case, the drainage surface will consist of a system of longitudinal wedges with one-dimensional curvature, for which the formwork can be made of flat sheets. This paper presents materials on the calculation and design of a shaft spillway of a hydroelectric complex with a dodecagonal cross-section for Algeria, and four shafts with an octagonal cross-section and two shafts with a tetragonal cross-section for Syria. The receiving hopper head is round-cylindrical, and the drainage surface is elliptical, which allows adapting the drainage surface to any initial design parameters of shaft spillways.
In the given materials there is given an analysis of the operation of existing constructions of devices for dissipation of excess energy of idle water discharges at hydraulic engineering facilities. The most applied design for dissipation of fl ow energy in the practice of hydraulic building in the world is stilling basins with straight axis made in prismatic or trapezoidal shapes which is appealing in their simplicity. The main disadvantage of these stilling wells in case of their using together with tubular spillways, especially having several strings, is practical impossibility to provide uniform distribution of specific discharges at the outlet from the spillway. This is connected with the fact that with several strings it is difficult to provide uniform distribution of specific discharges in the inlet section of the stilling well, it causes appearance of unstable regimes during operation of the stilling basin, especially in case of spillway operation with incomplete front which makes them inapplicable exactly for multi-point tubular spillways. At the same time, by deforming the stilling basin well flow in the form of a spiral, it is possible to reduce the length of the spilling basin by creating the possibility of the planned symmetric spreading of the flow in the output section in the diversion channel of the stilling basin, allowing using it if necessary to repeatedly expand the flow behind the spillway.
Inverted siphons and aqueducts are the most common methods of designing the intersections of canals with natural streams.
The textbook outlines the basics of calculation and design of reinforced concrete and stone structures in accordance with published normative documents SP 63.13330.2012 "Concrete and reinforced concrete structures. Basic provisions "and SP 15.13330.2012" Stone and armokamennye design". It considers the physical and mechanical properties of concrete, rebar, stone materials, reflects the modern classes of reinforcement used in construction, their characteristics and range. Much attention is paid to the calculation and design of water facilities, as well as environmental structures and structures in contact with the soil, such as retaining walls, underground concrete tanks for drinking water, reinforced concrete pipelines. The textbook reflects the long-term experience of teaching the authors of the discipline " Engineering structures "section" reinforced Concrete and stone structures". With this in mind, it provides many illustrations and explanations, and there are examples of calculation in the annexes. The textbook is written in accordance with the requirements of GEF VPO three plus and can be recommended for use in the educational process for the preparation of bachelors in areas 08.03.01 — "Construction", 20.03.02 — "environmental management and water use", 20.03.01 — "Technosphere safety" profile "environmental Engineering".
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