RU2623047C1 - Flood spillway for dams and other water supply facilities - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: device contains a pipeline consisting of a water intake 3, an inclined 4 and a water outlet section 5. The water intake section 3 is laid on the coastal slope of the dam, and the outlet 5 is located in the downstream. A horizontal platform 8 is formed on the inclined pipe segment 4 to form the sand insert 10. Above the platform 8, a loading aperture 9 with a lid 11 is provided, the lower surface of which fits snugly against the sandwich insert 10. The water outlet section 5 of the pipeline is mounted with respect to the horizontal platform 8 with an upward lift, in turn, the platform 8 is provided with a geotextile grid and communicates via a drainage channel 13 with a water well 14.

EFFECT: invention increases the discharge capacity of the spillway and ensures the activation only when the critical level is reached.

4 cl, 6 dwg

Description

The present invention relates to objects of hydraulic engineering, in particular to closed tubular spillways for dams and structures of this type, and is intended for the safe discharge of water during emergency floods.

There are known flood spillways containing a pipeline, the inlet head of which is laid in the upper pool, and the outlet in the bottom, while the heads are closed from the ends by gates with slotted openings for water intake and water outlet (see "Siphon spillway" according to AS USSR No. 1571123 A1, IPC E02B 7/18, publ. 06/15/1990.).

The disadvantage of the device is the actuation of the gates in the absence of emergency floods, with a slight excess of the water level relative to the normal retaining level (NPU).

Known devices in which the discharge rate of water depending on the water level is regulated using jumpers with sand or other eroded inserts ("Reserve spillway" according to US Pat. RU No. 2050433, IPC E02B 8/06, publ. 10.12.2005; "Flood spillway for dams "according to Pat. RU No. 2049195, IPC E02B 8/06, publ. 10.12.1995). The specified spillway, as a rule, is triggered by the threat of overflow of water through the crest of the dam. A spillway works together with it, which ensures discharge of water of small or medium floods at a water level slightly higher than the NPU (“Reserve spillway of soil dam” according to Pat. RU No. 2498007, IPC E02B 8/06, publ. 10.11.2013; “Reserve spillway "According to Pat. RU No. 2573328, IPC E02B 8/06, publ. 01.20.2016).

The disadvantage of this device is the low throughput of this culvert because of the small pressure on the crest of the structure.

Of the known devices, the closest analogue of the proposed solution for the technical nature and purpose is the flood spillway according to US Pat. RU No. 2265695, IPC E02B 8/06, publ. 12/10/2005.

The device includes a siphon spillway, the inlet head of which is laid in the upper pool, and the outlet in the lower pool above the low-water level, while the ends of the heads are closed with loose gates with slotted openings for water intake and outlet. The presence of slit openings at the inlet and outlet of the pipeline allows for a minimum excess of the forced level (FPU) over the normal-retaining level (NPU) of water in the upper downstream and to ensure dispersion of the flow at the outlet in the lower downstream.

The prototype works as follows. When the water level in the upper pool rises above the NPU, water begins to overflow through slotted holes in the inlet head and flow down the pipe laid with a slope to the outlet head. The spillway begins to work in a non-pressure mode when the section is partially filled. At the peak of the flood at the forced level (FPU) of water in the upstream, the spillway will operate in a siphon mode with a maximum open section.

The disadvantages of the prototype are the low throughput of the culvert, triggering at non-critical water levels, as well as the inability to arrange such a spillway on existing high-pressure structures.

The technical result from the use of the invention is to increase the throughput of the spillway and the operation of the device only when it reaches a critical level.

To achieve the specified technical result, the following set of essential features is used: in the flood spillway for dams and other water structures, containing, like the prototype, a pipeline consisting of a water intake, inclined and outlet sections, in contrast to the prototype, formed on an inclined section of the pipeline horizontal platform for the formation of a sand insert, with a loading hole with a lid being made above the platform, the lower surface of which fits snugly insert, while the water outlet of the pipeline is mounted in relation to the site with an upward rise, in turn, the site is equipped with a lattice with geotextiles and communicates through a drainage channel with a water well. To avoid filtering in the upper zone of the sand insert, a rotary damper is installed on the lower edge of the loading hole from the side of the inclined section of the pipeline. To use the device in low-pressure structures, a horizontal platform is mounted at the end of the inclined section of the pipeline. To use the device in high-pressure structures, a horizontal platform is mounted in the gap of the inclined section of the pipeline and is limited by a protrusion located in front of the end part of the specified section.

The essence of the proposed technical solution is to create a spillway with a high throughput capacity and triggered only during emergency floods by establishing a sand insert in the pipeline along the water flow path, which is eroded when critical values of the flow parameters are reached.

A comparison of the proposed invention and the prototype showed that the task is solved as a result of a new set of features, which proves the compliance of the invention with the patentability criterion of "novelty."

In turn, the information search in the field of hydraulic engineering did not reveal individual distinctive features of the claimed invention, which allows us to conclude that it meets the criterion of "inventive step".

The invention is illustrated in the drawing, where

in FIG. 1 presents a plan of a waterworks with a spillway according to p. 3,

in FIG. 2 longitudinal section along the axis of the spillway according to claim 3,

in FIG. 3 presents a plan of a waterworks with a spillway according to p. 4,

in FIG. 4 longitudinal section along the axis of the spillway according to claim 4,

in FIG. Figures 5 and 6 show figures explaining the choice of sizes of the sand insert depending on the critical value of the flood water level.

The proposed device is constructed (Fig. 1) on the coastal section of the dam dam 1 and includes (Fig. 2) a pipeline 2 with a water intake 3, an inclined 4 and a water outlet 5 sections. In the head of the water intake section, a trash holding grid 6 or slotted water intake is installed. The inclined section 4 can pass through the tunnel 7, cut down in the coastal rock mass. A horizontal platform 8 was mounted between the inclined 4 and outlet 5 sections of the pipeline. A device with the indicated location of the horizontal platform is intended for use in low-pressure structures. Above the platform 8, a loading hole 9 is made for loading the sand insert 10, which is closed after the operation is completed with the cover 11. The lower surface of the cover 11 is adjacent to the sand insert 10, which creates a reliable plug for non-critical water pressure. A rotary damper 12 is located on the lower edge of the loading hole 9 from the side of the inclined section 4 of the pipeline. A grill with geotextiles is installed in the center of the platform 8, through which the pipe 2 communicates with the drainage channel 13, which discharges water into the water well 14. To ensure a stable position of the sand insert the water outlet 5 of the pipeline is mounted in relation to the platform 8 with the rise up. This design solution allows you to form a funnel around the site 8, the side walls of which hold the insert 10 from erosion at non-critical water levels. In addition, the indicated position of the pipeline section 5 ensures the dispersion of the jet in the downstream, which avoids dangerous erosion of the bottom in the immediate vicinity of the outlet. In devices intended for use in high-pressure structures, platform 8 is mounted in the gap of the inclined section 4 of the pipeline (Figs. 3, 4) and is limited by a protrusion 15 located in front of the end part of the specified section and holding the insert 10 from erosion when water heads do not reach critical values.

The proposed device operates as follows.

Before the onset of the flood, sand is loaded into the pipeline through the hole 9, after which it is tamped and closed with a lid 11. As a result, a dense sand insert 10 of conical shape is formed in the path of the water flow. With small floods, the water level in the reservoir rises above the NPU, but does not reach a critical value. As the water level rises, the spillway is filled with water. When a critical level is reached, the water entering the pipeline under pressure produces an intensive erosion of the sand material, freeing the device from the sand insert. The rotary damper 12 is rotated with the flow, without interfering with the passage of the flood flow. Intensive discharge occurs to the design level of the reservoir, after which the device stops working.

Spillway capacity is calculated by the formula:

,

,

where μ is the flow coefficient;

ω is the cross-sectional area of the tubular spillway, m ² ;

g = 9.81 m / s ² - acceleration of gravity;

H is the water head at the spillway, measured from the critical water level to the center of the outlet of the spillway.

The following is a calculation of H _crit. (see also Fig. 5, 6), at which erosion of a sand insert with a ridge width (b _g ) of 4.0 m begins; height (h in _. ) 4.0 m, length (L) 21.3 m and slope angle (α) 20 °. The insert is designed for use in a spillway device of a high-pressure structure. Using the method of electrohydrodynamic analogies (EGDA method) for many profiles of sand inserts with different geometric characteristics, the position of the lines of equal pressure is determined: 0.8h ... 0.2h, where h is the unit design pressure applied to the side surface of the sand insert.

The streamlines plot the output filtering gradients for this insert. Output gradients are determined by the formula:

where l is the length of the streamline section between the equal pressure line 0.2h and the external slope of the sand insert. Required head H _crit. depends on the critical output filtering gradient J _cr. therefore, in the formula, the unit design head h can be replaced by the critical head H _crit. and the output filtering gradient J is the critical output filtering gradient J _cr. .

According to SP 39.13330.2012 “Dams from soil materials”, the value of critical average pressure gradients for fine sand is 0.75, for medium sand - 1.0. Thus, for insertion of medium sand with a crest width of 4.0 m; 4.0 m high and a slope angle of 20 °, the value of N _crit. = 9.5 m.

The described device was developed by specialists of the Department of Hydrotechnical Structures, Structures and Hydraulics FSBEI HE "State University of the Sea and River Fleet named after Admiral S.O. Makarova "as part of research work. Calculations were made that showed the possibility of using the device according to claim 3 on low-pressure navigable waterworks of the Volga-Baltic, Volga-Don waterways; and under item 4 at high-pressure hydroelectric facilities: Zeya hydroelectric station, Bureyskaya hydroelectric station, Krasnoyarsk hydroelectric station.

The above allows us to conclude that the invention meets the criterion of "industrial applicability".

Claims (4)

1. A flood spillway for dams and other water-retaining structures, comprising a pipeline consisting of a water intake, inclined and water outlet sections, the water intake section being laid on the coastal slope of the dam inset, and the water outlet in the downstream, characterized in that a horizontal line is formed on the inclined section of the pipeline a platform for forming a sand insert, and a loading hole with a lid is made above the platform, the lower surface of which fits snugly against the sand insert, while the outlet The second section of the pipeline is mounted with respect to a horizontal platform with a rise upward, in turn, the horizontal platform is equipped with a lattice with geotextiles and communicates through a drainage channel with a water well. 2. The flood spillway according to claim 1, characterized in that a rotary damper is installed on the lower edge of the loading hole from the side of the inclined section of the pipeline. 3. The flood spillway according to claim 2, characterized in that the horizontal platform is mounted at the end of the inclined section. 4. The flood spillway according to claim 2, characterized in that the horizontal platform is mounted in the gap of the inclined section of the pipeline and is limited by the protrusion located in front of the end part of the specified section.

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