RU2375520C1 - Open spillway on non-rock foundation - Google Patents

Abstract

FIELD: construction industry, water engineering.

SUBSTANCE: invention refers to water engineering and can be used for erecting low pressure or medium pressure open spillway on non-rock foundation. Spillway includes head part made from concrete, discharge part made in the form of tray with rapid longitudinal slope and water-jet walls at its bottom, which provide formation of hydraulic jumps, end part made in the form of water-jet, at least two pipes providing the passage of low water stream flows, and natural or artificial drain element provided at the tray bottom. Bottom, side and water-jet walls of the tray are made from gabions filled with stones and connected to each other with wire and forming solid flexible gabion structure of the tray, which is enclosed from below and on sides in waterproof membrane. Pipes are made from metal, located along the tray on gabions of its bottom along one side wall of the tray. Inlet pipe section crosses the weir body of head part and is attached to that weir. Gabions of water-jet wall are located on upstream side, in relation to water flow direction, from rigid cross element and are adjacent to that cross element.

EFFECT: invention improves reliability and repairability of spillway.

8 cl, 8 dwg, 2 ex

Description

The invention relates to hydraulic engineering and can be used in the construction of low-pressure or medium-pressure open spillway on a rock-free basis, both of natural origin (coastal spillway) and artificial (spillway soil dam).

Known spillway [1, p. 414-418], containing the head, discharge (quick flow in the form of a tray) and end (water) parts made of cast concrete. Such a spillway is usually located ashore on rocky or non-rocky natural soil, which has sufficient strength, including filtration, and a drainage element is provided under the bottom of the tray.

The disadvantages of this technical solution are:

- high costs due to the large volume of concrete work;

- the rigidity of the design of the tray adversely affects its operation, therefore, the spillway may be destroyed as a result of the dynamic impact of the water flow (the same reduced flow);

- spillway is not applicable on weak and subsiding soils. Known spillway [1, p. 384-388], which differs from the previously described in that the bottom of the tray is made of thin wedge-shaped reinforced concrete slabs on the reverse drainage filter. Such slabs are staggered from bottom to top on the lower slope of the dam with the inlet of the upper row on the lower row, which forms a flexible coating of the spillway of the soil dam, which is attached to the blind parts of the dam by fixed side slopes or retaining walls.

The disadvantage of this relatively economical technical solution is its lack of reliability due to the following reasons:

- due to the high permeability of the bottom of the tray, the bottom prism of the dam is saturated with moving water, which increases the requirements for the material of the drainage filter and to drain water from it, and also leads to a more gentle execution of the overflow slope of the dam;

the dynamic effect of the flow on the tray causes uneven deformation of the flooded slope of the dam, which can disrupt the mutual engagement of the plates and damage the tray;

- in the case of water passage through the spillway throughout the year, the downstream slope of the dam is constantly saturated with water, which reduces the maintainability of the spillway, and in severe climatic conditions, frost can form on the spillway, which is unacceptable under operating conditions.

Known spillway [2], which has the form of rapid flow (the same - the tray) of a trapezoidal cross-section, the fastening of which is an integral flexible design made along the entire length of the semi-cylindrical gabions interconnected on the inverse filter. At the same time, gabions are stacked with their ridges upward with an orientation transverse to the longitudinal axis of the flow, the space formed between the semi-cylindrical gabions is filled with concrete, forming a coating with expansion joints along the gabion ridges, and the inlet part of the current and its outlet part are embedded into the ground by gabions.

In rapid flow, gabions and split concrete cladding work together to create a seamless, flexible structure. However, such a combined fast-current mount formed by split concrete cladding, gabions and a reverse filter is strongly permeable in all directions, which leads to the following disadvantages of this technical solution:

- at water levels in front of the inlet part of the quick-flow above the sole of the mount (the same above the sole of the inverse filter), the water moves inside the mount, and in a turbulent mode, and saturates the base, which increases the requirements for the materials of the inverse filter and base and to drain water from them, and also causes a more gentle longitudinal slope of the rapid current;

- the concrete coating does not provide a sufficient rate of quenching of the flow energy within the discharge part of the flow, which limits the scope of such a flow relative to its height (difference in water levels in the downstream waters), longitudinal slope and specific water flow rate;

- in the winter season, water from the mount will pour onto the surface of the concrete cladding and form ice, which complicates the operation of the spillway.

The closest technical solution is a spillway gabion dam [1, p. 409, 410], the body and the water part of which is a masonry of interconnected wire mesh gabions filled with stone and forming a solid gabion structure, mating with the deaf parts of the dam. In this case, the head part of the spillway gabion dam contains concrete or asphalt concrete lining, and the discharge (spillway) part of it is made stepwise or fleeting. An anti-filtration element in such a dam is a top prism made of soil or a waterproof lining of the top face of the dam.

The disadvantages of this technical solution are the high costs, the limited scope of application relative to the height of the spillway dam and the specific consumption of water, insufficient reliability and low maintainability, which are due to the fact that:

- the volume of gabion masonry rapidly increases with increasing dam height;

- low rate of quenching of the flow energy within the discharge part of the dam at high specific water flow rates, which leads to high dynamic loads on the gabion structure, increasing with increasing height of the dam;

- insufficient strength of the gabion structure;

- the perception of the entire shear hydrodynamic effects of the flow is carried out only by the gabion structure and its base.

- when water passes, water saturation of the lower prism of the dam occurs, including partially its deaf part, which causes the effect of volumetric filtration forces directed towards the downstream in the entire lower prism of the dam;

- carrying out repair work without completely stopping the passage of water through the spillway is difficult;

- there is icing of the discharge part in the winter season.

The problem to which the invention is directed, is

cost savings, expanding the scope of open spillway with

discharge part of gabions, increasing reliability and maintainability

spillway.

The technical result from the use of the invention is that;

- reduced the volume of the gabion structure;

- increased rate of quenching of energy flow within the discharge part;

- increased reliability of the gabion structure;

- reduced transmission of shear hydrodynamic effects of the flow from the gabion structure to the base of the discharge part;

- prevented filtering in the base of the discharge

parts;

- flooding of the gabion structure of the dam was prevented when small low-flow water flows were passed through the spillway;

- when skipping high costs in the tray, the specific costs of the open water flow are reduced.

This problem is solved, and the technical result is achieved by the fact that the open spillway on a non-rocky base contains a head part made of concrete, a waste part made in the form of a tray with a transient longitudinal slope and with water-borne walls at its bottom, which ensure the formation of hydraulic jumps, the end part made in the form of a water hole, at least two pipes that allow the passage of small low-flow water flows, and a natural or artificial drainage element at the base of the tray. The bottom, side and water walls of the tray are made of gabions filled with stones, connected by a wire and forming an integral flexible gabion structure of the tray, which is enclosed in a waterproof membrane from below and from the sides. The pipes are made of metal, located along the tray on the gabions of its bottom, one at a side of the side wall of the tray, while the inlet section of the pipe crosses the body of the overflow threshold of the head part and is attached to this threshold. The gabions of the watering wall are located on the upper side with respect to the direction of water flow from the rigid transverse element attached to the pipes and are adjacent to this transverse element.

Additionally:

- the longitudinal slope of the bottom of the tray is constant or increases in the direction of flow;

- the average value of the longitudinal slope of the bottom of the tray icp, a fraction of one, satisfies the condition:

0.33> i _cp >0.20;

- the waterproof membrane is made of a polymer film enclosed in geotextiles;

- gabions adjacent to the pipe are attached to it;

- gabions adjacent to the head are attached to it;

- the rigid transverse element is a metal I-beam located sideways on the pipes and abutting against the gabions of the side walls of the tray by means of additional elements;

- the outlet pipe section is located within the end part of the spillway, is equipped with a flat supporting element and a hydraulic nozzle directing the water stream leaving the pipe from the base.

Exactly:

- the implementation of the tray in the form of an integral flexible gabion structure allows to reduce the volume of gabion masonry;

- execution in the tray of gabions watering walls provides intensive quenching of energy flow;

- pipes and rigid transverse elements increase the reliability of the gabion design of the tray;

- transfer of a part of the shear hydrodynamic effect of the flow from gabions by means of rigid transverse elements and pipes to the concrete head of the spillway increases the shear stability of the entire gabion design of the tray in the direction of flow, while the dynamic action on the head part improves the quality of soil pairing with the concrete structures of the head part;

- the conclusion of the gabion design of the tray in a waterproof membrane completely prevents the filtering effect of water at the base of the discharge part;

- the use of pipes to pass small low-flow water costs prevents icing of the spillway and simplifies the repair work on the spillway;

- when high flow rates of water are passed through, pipes operating in pressure mode at high speeds of water in them reduce the specific flow rates of water in an open tray.

The analysis of the existing patent and scientific and technical literature showed that the proposed set of features to achieve the specified new technical result is not currently known, which allows us to conclude that there is both novelty and inventive step.

The invention is illustrated by drawings.

Figure 1-6 shows an open spillway in the form of a spillway (spillway) soil dam, example 1, namely: figure 1 shows a spillway plan; figure 2 is a longitudinal section of a spillway; in Fig.3 is a section aa in Fig.2; figure 4 is a section bB in figure 2; figure 5 is a section CC in figure 2; Fig.6 is a section DD in Fig.2. Figures 7 and 8 show a coastal spillway, Example 2, namely: Fig. 7 shows a spillway plan; on Fig-section EE in Fig.7.

Example 1. The reservoir 1 is created by a soil dam, which consists of two deaf parts 2 and a spillway 3 (figure 1). The lower prism 4 of the spillway part 3 of the dam and powder 5 to it are made of gravel and pebble soil and form a drainage base 6 of the open spillway 7, consisting of a head part 8, a discharge part 9 and an end part 10.

The head part 8 is made of concrete and contains a spillway threshold 11, which is located on the crest of the core 12 of the spillway part 3 of the dam. The discharge part 9 is made in the form of a tray 13, which has a transient longitudinal slope and water walls 14 at its bottom 15, and the end part 10 is made in the form of an expanding water well 16.

The bottom 15, the side walls 17 and the water walls 14 of the tray 13 are made of gabions 18 filled with stones, connected by a wire and forming an integral flexible gabion structure of the tray 13, enclosed in a waterproof membrane 19 from below and from the sides, which is made of a polymer film and enclosed in geotextiles.

The spillway 7 contains two pipes 20, which are low consumption, made of metal and are located along the tray 13 on the gabions 18 of its bottom 15, one at each side wall 17. The inlet section 21 of the pipe 20 intersects the body of the spillway 11 and is attached to this threshold 11 and coating 22. The output section 23 of the pipe 21 is located within the end part 10 of the spillway 7, is equipped with a flat supporting element 24 and a hydraulic nozzle 25.

Gabions 18 of the waterwall 14 with respect to the direction of the flow of water 26 (hereinafter referred to as the flow) in the tray 13 are located on the upper side of the rigid transverse element, which is an I-beam 27, is located sideways on the pipes 20 and is attached to them by means of a fastening element 28 (FIG. .6). The metal I-beam 27 abuts against the gabions 18 of the side walls 17 of the tray 13 by means of additional elements 29, and the gabions 18 of the water-boring wall 14 are adjacent to the I-beam 27.

Gabions 18 adjacent to the head part 8 are attached to it, and gabions 18 adjacent to the pipes 20 are attached to these pipes 20.

The longitudinal slope of the bottom 15 of the tray 13 in accordance with the operation of the pipes 20 in tension constant or increases in the direction of flow. At the same time, the longitudinal slope provides rapid (turbulent) movement of water in the tray 13, and its average value i _cp , a fraction of a unit, usually satisfies the condition: 0.33> i _cp > 0.20. This corresponds to laying the bottom 15 of the tray 13 as 3 <m <5. With a steeper slope, high tensile forces arise in the pipes 20, which are transmitted to the head part 8 of the spillway 7, while the execution of the tray 13 is complicated. With a more gentle slope, the length of the discharge part 9 increases and the efficiency of the pipes 20 decreases in terms of their perception of the shear the effects of flow on tray 13.

The drawing shows other elements of the spillway part 3 of the dam, namely:

30 - mount prism;

31 - geotextiles;

32 - stand;

33 - opener;

34 - berm;

35 - sloping mount;

36 - siphon branch;

37 - surface water table;

38 - walls of a water well;

39 - bottom of a water well;

40 - backfill;

41 - the basis of natural origin.

The spillway part 3 of the dam is erected simultaneously with the adjacent deaf parts 2 of the dam to a predetermined level of the lower prism 4, powder 5, core 12 and high prism 30. Then, on the prepared base 6, within the end part 10, geotextiles 31 are laid in two layers, and in within the discharge part, a membrane 19 is laid upwards. The gabion masonry of the water well 16 is performed and the gabion masonry of the tray 13 with the water walls 14 is successively bottom-up; pipes 20 and I-beams 27 are laid. The head part 8 is concreted: the overflow threshold 11 with abutments 32 (dock structure), openings 33 and fastening 22. Through the head part 8, a bridge is constructed (not shown in the drawings), the dusting powder 5 is completed, the berm 34 and the slant fastening 35 are completed. If necessary, a siphon branch 36 is attached to the pipe 20 .

Gabions 18 are made of boxed nets that are filled with stone material. Gabions 18 have a rectangular shape with dimensions taken, for example, in meters 1 × 1 × 2, and the diameter of the pipes 20 is taken to be 0.5 m. When masonry is performed, the gabions 18 are connected with a zinc-coated wire. The manufacture of gabions 18 and the execution of them masonry is carried out in accordance with standards [3-5].

Spillway 7 works in conjunction with the entire spillway dam 3 and as follows.

At all levels of water in the reservoir 1, the drainage base 6 provides a lowering of the surface of the groundwater 37 below the waterproof membrane 19, which prevents the weighing effect of water on the bottom 15 of the tray 13.

Small low-flow costs are passed through low-flow pipes 20, which prevents any impact of the flow on the gabion structure of the tray 13 within the discharge part 9 and does not interfere with the inspection and repair of the tray. The support element 24 prevents the twisting of the pipe 20, and the hydraulic nozzle directs the flow of water from the pipe 20 from the bottom 39 of the water well 16. In this case, the pipe 20, brought downstream beyond the end part 10, under favorable conditions allows pumping water to the consumer, and equipped with a siphon branch 36, this pipe allows for the operation of reservoir 1 for water supply. In this case, the mark of the bottom of pipe 20 (Fig. 2), which is located below the mark on ord 11 (▼ nop).

At high flow rates, the water in reservoir 1 can rise to its maximum level (max. ▼ HC). At the same time, most of the water moves along the tray 13, the water walls of which together with the I-beams 27 provide a differential form of the flow of water along the tray 13 with the formation of a jump in front of each water wall 14, which provides an intensive quenching of the flow energy. At the same time, through the I-beams 27 and pipes 20, part of the shear hydrodynamic effect of the flow from gabions 18 is transferred to all concrete elements of the head part 8 and to the dam soil involved, which increases the stability of the entire gabion structure of the tray 13 for shear in the direction of flow 26. Pipes 20 and I-beams 27 with additional elements 29 perceive lateral soil pressure transmitted to them by the side walls 17, which increases the stability of the walls 17.

When water moves along the tray 13, the waterproof membrane 19 prevents water saturation of the bottom prism 4 of the dam, which increases the shear stability of the entire gabion structure of the tray 13 in the flow direction.

The described spillway, like any spillway in the form of a drain soil dam, does not occupy new areas on the territory.

Example 2 (Fig.7 and 8). The coastal spillway 7 is located on a non-rocky base 41 of natural origin and further comprises a supply channel 42 and a discharge channel 43.

In order to more reliably lower the level of groundwater 37 in the base 41 below the permeable membrane 19 and increase the throughput of the spillway 7, it can be characterized by the following differences with respect to example 1.

1. The membrane 19 is located on the drainage layer 44, made on a prepared non-rocky base 41 of natural origin and equipped with drainage pipes 45.

2. The spillway 7 contains an additional pipe 46, which is located in the middle of the bottom of the tray 13 and thus converts the single-span tray 13 into a two-span, and with a larger number of additional pipes 46, into a multi-span tray 13.

3. The side walls 17 of the tray 13 are made of gabions 18 in the form of a sloping mount 47.

Such a coastal spillway in comparison with the spillway described in example 1 has the following advantages:

- works regardless of the dam;

- increased width of the spillway, therefore, its throughput;

- increased reliability and efficiency;

- the efficiency of the pipes 20 is increased, and their diameter, as well as the diameter of the additional pipe 47, does not require coordination with the dimensions of the gabions.

The invention allows to create an open spillway on a rocky base with a tray of gabion masonry at a construction height of 20-25 m and with a specific water flow rate of 10-12 m ³ / s per 1 m.

Information sources

1. Waterworks: Textbook. for universities: In 2 hours, Part 1 / L.N. Rasskazov, V.G. Orekhov, Yu.P. Pravdivtsev and others; Ed. L.N. Rasskazova. - M.: Stroyizdat, 1999.

2. Patent of the Russian Federation No. 2239021, cl. EBO 8/06, publ. 10/27/2004.

3. GOST R 52132-2003 Mesh products for gabion structures. Technical conditions

4. GOST R 51285-99 Twisted wire mesh with hexagonal cells for gabion structures. Technical conditions

5. GOST R 50575-93 Steel wire. Zinc coating requirements and coating test methods.

Designations:

1 - reservoir

2 - deaf part (dam)

3 - spillway (dam)

4 - bottom prism (dam)

5 - powder

6 - base (bulk)

7 - spillway

8 - head part (spillway)

9 - discharge part (spillway)

10 - end part (spillway)

11 - spillway threshold (head part)

12 - core (dam)

13 - tray (the same - discharge part)

14 - water wall

15 - bottom (tray)

16 - water well

17 - side walls (tray)

18 - gabions

19 - membrane

20 - pipe

21 - inlet section (pipes)

22 - coating

23 - output section (pipes)

24 - supporting element

25 - hydraulic nozzles

26 - water flow (hereinafter referred to as the flow)

27 - I-beam

28 - fastener

29 - additional element

30 - mount prism

31 - geotextiles

32 - stand

33 - opener

34 - berm

35 - sloping mount (stone)

36 - siphon branch

37 - surface water table

38 - walls of the water well

39 - bottom (water well)

40 - backfill

41 - base (natural origin) (Example 2.)

42 - inlet channel

43 - discharge

44 - drainage layer

45 - drainage pipe

46 - additional pipe

47 - sloping mount (gabions).

Claims (8)

1. An open spillway on a non-rocky base, characterized in that it contains a head part made of concrete, a discharge part made in the form of a tray with a transient longitudinal slope and with water walls at its bottom, which provide the formation of hydraulic jumps, the end part made in the form of a water hole, at least two pipes that allow the passage of small low-flow water flows, and a natural or artificial drainage element at the base of the tray, while the bottom, side and water walls of the tray are made of gabions filled with stones, connected by a wire and forming an integral flexible gabion structure of the tray, which is enclosed in a waterproof membrane from below and from the sides, pipes are made of metal, located along the gabion of its bottom one at a time from the side wall of the tray, and the inlet pipe section intersects the body of the spillway threshold of the head part and is attached to this threshold, the gabions of the watering wall are located on the upper side, in relation to the direction of the water flow, from the rigid transverse element and are adjacent to this transverse element. 2. The spillway according to claim 1, in which the longitudinal slope of the bottom of the tray is constant or increases in the direction of water flow. 3. The spillway according to claim 1, in which the average value of the longitudinal slope of the bottom of the tray i _cp , a fraction of one, satisfies the condition:
0.33> i _cf. > 0.20. 4. The spillway according to claim 1, in which the waterproof membrane is made of a polymer film enclosed in geotextiles. 5. The spillway according to claim 1, in which the gabions adjacent to the pipe are attached to it. 6. The spillway according to claim 1, in which the gabions adjacent to the head are attached to it. 7. The spillway according to claim 1, in which the rigid transverse element is a metal I-beam located sideways on the pipes and abutting against the gabions of the side walls of the tray by means of additional elements. 8. The spillway according to claim 1, in which the outlet section of the pipe is located within the end part of the spillway, equipped with a flat support element and a hydraulic nozzle directing the jet exiting the pipe from the base.

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