RU2474646C1 - Rock and earth dam - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: dam comprises a core from clayey soil, upper and lower transition zones from a non-cohesive soil, upper and lower prisms, at least the lower of which is made from rock riprap, a head of non-swelling soil, a retaining wall from concrete, a layer from an air-impermeable material and equipment required for operation of the dam. The dam head includes a heated reinforced concrete gallery, between external supports of which there is a section of free surface of the core comb arranged. The retaining wall has specified height, is installed in the dam base at the lower side of the core and adjoins it in a water impermeable manner. The retaining wall comprises in its body a footway on elevations that are not flooded at the side of the lower reach. The layer of the air impermeable materials covers the dam comb and its lower slope, at least within the height of the head and has dark colour. The upper wall of the gallery is made as water impermeable, and the lower wall of the gallery comprises air ducts, which provide for hydraulic connection of the gallery cavity with the pore space of the rock riprap of the head and the lower prism. The retaining wall comprises air ducts, which provide for hydraulic connection of the footway cavity with the pore space of the rock riprap of the lower prism in the place of its adjacency to the lower face of the retaining wall. Equipment may via the gallery cavity and the footway cavity provide for forced motion of warm atmospheric air along the rock riprap of the lower prism.

EFFECT: invention provides for positive temperatures near a comb and a lower face of a dam core, core freezing is prevented, and higher dam reliability during its operation.

12 cl, 2 dwg

Description

The invention relates to hydraulic engineering and can be used in the construction of stone and earth dams in the northern climatic zone.

Known stone-earthen dam containing a core of clay soil, the upper and lower transitional zones from incoherent soil, the upper and lower prisms (lateral) of the stone outline and the head of non-porous soil [1].

In such dams built in the northern climatic zone, the upper part of the core has already been frozen from the dam crest to a depth of 9 m or more - Vilyuyskaya 1-2-3, Ust-Khantayskaya, Kureyskaya, Kolyma and others.

As a result of soil self-compaction in the lower thawed part of the core, the frozen head of the dam hangs on the lateral prisms and, accordingly, the soil is decompressed directly at the interface between frozen and thawed soils. Such decompression is dangerous in the suffusion sense, especially in the case of using soils with a low, less than 7 plasticity number in the core — such clay soils prevail in the northern climatic zone. At the same time, during the erection of a stone-earthen dam in especially harsh climatic conditions, the lower prism can freeze and form a continuous waterproof ice-ground massif, which adjoins the permafrost base and the dam core. This occurs especially outside the channel talik at lower coastal sections of the dam. Under such conditions, the frozen bottom transitional zone cannot divert water filtered through the core. Therefore, thawed water-saturated areas preserved in the transition zone and in the lower prism operate in unpredictable extreme conditions, which can lead to emergency situations, as happened at the Kolyma hydroelectric dam when it was erected, where the average annual air temperature reaches minus 13 ° С [2 ].

A similar soil dam is known, which additionally includes a thermal curtain, which is placed in the cross section of the dam in the lower transition zone and is made in the form, for example, of a series of wells located in series along the length of the dam and its entire height [2 and 3]. In this dam, the transition zone and drainage at the base of the lower prism are located in the zone of positive temperatures created by the thermal curtain. However, the creation of a thermal curtain along the dam’s length through deep wells and the operation of this curtain are associated with high costs, while in the dam the upper part of the core and the drainage part of the drainage at the base of the dam are not protected from freezing in especially harsh climatic conditions, which reduces its reliability.

The reliability of such a dam will be enhanced if it is additionally equipped with a means to create a positive temperature in the upper part of the core, and the drainage part of the drainage provides unhindered access to the river, as provided in the source [4]. During operational fluctuations in the downstream of the river water levels in the drainage part of the drainage, positive temperatures are constantly maintained. This occurs due to the periodic entry and exit of river water into the pores of the stone outline of the drainage part of the drainage with an increase or decrease in the water level in the river. However, the costs of creating a thermal curtain in the dam and its operation, as well as maintaining positive temperatures in the upper part of the core remain high.

Known stone-earth dam containing a core of clay soil, the upper and lower transitional zones of incoherent soil, the upper and lower prisms of the stone outline and the head of non-porous soil, which accommodates a heated reinforced concrete gallery. A section of the free surface of the ridge of the core is located between the outriggers of the gallery, and the upper stack of the gallery is waterproof [5]. The heated gallery creates an efficient and reliably controlled heating of the upper part of the core. However, in such a dam, freezing of the lower prism and the lower transition zone and their freezing with the core in the middle and lower part of the dam is not prevented, which reduces the reliability of the dam.

A stone-earthen dam is known, containing a retaining wall made of concrete, which has a predetermined height, is located at the bottom of the dam on the bottom side of the core, is adjacent to the core waterproof, contains lost in its body on marks not flooded from the downstream side and is adapted to skip the spring flood during the construction of the dam [6]. In addition, for such a dam, the source [7] provides for the implementation in the retaining wall of the air ducts, which provide hydraulic connection of the cavity is lost with the pore space of the stone outline of the lower prism at the point of its abutment to the lower edge of the retaining wall. It also provides equipment that is able to provide forced movement of warm atmospheric air through a stone sketch of a lower prism through a cavity.

In such a dam, freezing of the lower prism and lower transition zone and their freezing with the core in the middle and lower part of the dam can be prevented, however, the upper part of the dam core remains unprotected from frost penetration (other protection means are required), which reduces the reliability of the dam.

The closest technical solution to the proposed solution is a stone-earthen dam [8, Figure 1], containing a clay soil core, upstream and downstream transition zones from incoherent soil, upstream and downstream prisms from stone outline, a screen made of airtight material, and a career cloak small things or sand and gravel soil and equipment necessary for the operation of the dam. The screen is located inside the bottom prism so that the screen and the bottom face of the core and the surface of the base or water in the channel part of the dam form an air duct in the rock outline along the dam near the transition zone, the entrance to which is on the crest of the dam, and the outlet on the lower part of its downhill . Moreover, the dam equipment is able through the cavity of the linear structure (hangar) to provide forced movement of warm atmospheric air along the stone outline of the air duct. In this case, the hangar is made on the crest of the dam above the entrance to the air duct, i.e. above the bottom prism, away from the crest of the core. This provides positive temperatures within the air duct, which increases the reliability of the dam.

The source [8] also reports that a similar technical solution was filed on 06/06/2010 for the invention No. 2010127897 “Dam from soil materials”. The content of this application to the applicant of the present invention is not yet known.

The disadvantages of this dam are as follows.

1. The airtight screen inside the stone outline and the hangar on the crest of the dam significantly complicate the design of the dam, which leads to an increase in the cost of its construction.

2. The location of the hangar above the entrance to the air duct, ie away from the ridge of the core, does not prevent freezing of the upper part of the core in the cold season, which reduces the reliability of the dam during its operation. In this case, the implementation of the hangar can lead to an increase in the width of the dam crest, which will increase the cost of erecting the dam.

The problem to which the invention is directed, is to reduce the cost of creating a dam and increase the reliability of the dam during its operation.

The technical result from the use of the invention is to simplify the design of the dam and prevent freezing of the core of the dam.

The problem is solved, and the technical result is achieved by the fact that the dam has a core of clay soil, top and bottom transition zones of incoherent soil, top and bottom prisms, at least the bottom of which is made of stone, the head is made of non-porous soil, retaining a concrete wall, a layer of airtight material and equipment necessary for the operation of the dam. The tip of the dam accommodates a heated reinforced concrete gallery, between the outriggers of which there is a section of the free surface of the core crest. The retaining wall has a predetermined height, is located at the bottom of the dam on the bottom side of the core and is watertight to it and contains a loss in its body on marks that are not flooded from the downstream side. A layer of airtight material covers the crest of the dam and its bottom slope, at least within the height of the tip. The upper wall of the gallery is made waterproof, and the lower wall contains air ducts that provide hydraulic connection between the gallery cavity and the pore space of the stone outline of the head and the lower prism. The retaining wall contains air ducts that provide a hydraulic connection between the cavity and the pore space of the stone outline of the lower prism at the point where it adjoins the lower face of the retaining wall. At the same time, the equipment is able to provide forced movement of warm atmospheric air through a stone sketch of the lower prism through the gallery cavity and the cavity are lost.

Additionally:

- the layer of airtight material has a dark color, and the value of its absorption coefficient of solar radiation (solar radiation, light) is not less than 0.8;

- the dam is equipped with hatches with closures that can isolate the gallery cavity and / or the cavity is lost from direct communication with the atmosphere;

- the dam is equipped with devices, each of which is capable of blocking the gallery cavity or the cavity is lost;

- a predetermined number of air ducts from among those providing the hydraulic connection of the gallery cavity and the cavity are lost with the pore space of the stone outline are provided with shutters, each of which is installed at the entrance to the air duct from the side of the cavity;

- a drainage is made at the base of the lower prism, which is located along the retaining wall and adjacent to it;

- the equipment is capable of supplying pressure to the gallery cavity by pressure;

- the equipment is capable of discharging air from the cavity by discharge;

- the equipment is capable of supplying pressure into the cavity;

- the equipment is capable of discharging air from the gallery cavity by discharge;

- a layer of airtight material is made of asphalt or asphalt concrete;

- drainage is made on the lower edge of the retaining wall.

Fulfillment of the heated gallery according to the indicated rules, and at the dam base — a retaining wall with a lost one, as well as covering the crest of the dam and partially downhill slope with an airtight layer made mainly of asphalt or asphalt concrete, ensures the achievement of the previously indicated technical result: simplification of the dam design and preventing freezing of the dam core.

It is the creation by means of equipment of a differential pressure in the cavity of the gallery and the cavity that is lost provides a directed movement of air over the entire height in the immediate vicinity of the core, which eliminates the internal airtight screen from the prototype dam. At the same time, the heated gallery prevents the freezing of the upper part of the core and functionally completely replaces the hangar.

The creation of directed air movement in the lower prism of the dam is not the main purpose of the gallery, nor lost. Moreover, even the air ducts in the retaining wall on the channel section of the dam are designed primarily for aeration of the flow when the water overflows through the unfinished dam. At the same time, highly effective directional air movement in the lower prism of the proposed dam can be created by means of equipment only if the gallery is simultaneously activated and lost in a given mode. Moreover, the effectiveness of their joint work over a period of time is significantly higher than the sum of the efficiencies of their separate (alternate) work for two consecutive such periods. Therefore, according to the applicant, the proposed invention meets the criterion of "inventive step".

The proposed dam is illustrated by drawings, where figure 1 shows the proposed dam, a cross section on the channel section; figure 2 is a transverse section on the coastal site.

The dam was erected on a rocky foundation 1, located on the channel section of the dam in a thawed state, and on the coastal sections - in a frozen state.

The dam has a core 2 of clay soil, filters 3 and 4 of incoherent soils forming the upper transition zone, filters 5 and 6 of incoherent soils forming the lower transition zone, the upper 7 and lower 8 prisms of the stone outline, head 9 of non-caked soils and retaining wall 10 of concrete.

The head 8 accommodates a heated reinforced concrete gallery 11, between the outriggers 12 of which there is a portion of the free surface of the ridge 13 of the core 2. The upper stack 14 of the gallery 11 is made waterproof, and the bottom wall 15 contains air ducts (hereinafter: channels) 16, which provide hydraulic communication between the gallery cavity 11 with the pore space of the stone outline of the head 9 and the bottom prism 8. The channels 16, all or part of them, are equipped with shutters 17, each of which is installed at the entrance to the channel 16 from the side of the gallery cavity 11, and Immediately after leaving each channel 16, a grating 18 is installed.

The gallery 11 is heated by, for example, electric heaters (not shown) or water pipes 19.

The retaining wall 10 has a predetermined height, is located at the bottom of the dam on the lower side of the core 2 and is adjacent to it waterproof and contains a loss of 20. The retaining wall contains air ducts 21 that provide hydraulic connection to the cavity. 20 with the pore space of the stone outline of the lower prism 8 in the place of its abutment to the lower face of the retaining wall. Channels 21, all or part of them, are equipped with shutters 22, each of which is installed at the entrance to the channel 21 from the cavity side, 20 are lost, and immediately after the exit from each channel 21, a grill 23 is installed.

Crest 24 of the dam, i.e. the head 9, and the bottom slope 25 of the dam, at least within the height of the head 9 is covered with a layer 26 of airtight material, such as asphalt or asphalt concrete. Such a layer 26 has a dark color, and the value of its absorption coefficient of solar radiation (solar radiation, light) is not less than 0.8. The middle part of the height of the bottom slope is 25, i.e. below layer 26, it is covered with a poorly permeable layer 27 of sand and gravel soil (ASG).

The height H _{st of the} retaining wall 10 is assigned in the channel part of the dam from the condition of exceeding the surface 28 of the overflow part of the dam and the conditions of non-flooding of the cavity are lost 20 from the downstream side with a maximum level of HC water in the downstream of the constructed dam. In the shore of the dam height H _article retaining wall 10 of prescribed conditions undrowned footway cavity 20, i.e. the duct 21 in the transverse section of the dam are always above the water level in the drain 29 (Fig.2). This drain 29 is made at the base of the lower prism 8, is located along the retaining wall 10 and is adjacent to it. It is advisable to place the drainage tray 30 on the lower edge of the retaining wall 10, and provide the loss 20 with heating means, for example, a water pipe 31, which will ensure positive temperatures in the drainage 29.

The dam has the equipment necessary for its operation in the form of fans, air ducts, pumps and a gate blocking the cavity (not shown). This equipment is able through the cavity of the gallery 11 and cavity lost 20 to provide during the warm period of the year forced air movement along the stone outline of the bottom prism 8, for example, by supplying pressure air to the cavity of the gallery 11 isolated from the atmosphere and removing air from the cavity lost by 20 discharge.

As a result of such ventilation between the core 2 and the temperature boundary 32, which is established in the lower prism between thawed and frozen soils, a highly permeable thawed air duct 33 is formed, mainly through which air moves in a downward flow.

In the drawings, the air movement is shown by lines 34, continuous within the air duct 33 and dashed within the weakly permeable frozen bottom prism 8. In addition, in Fig. 1, the elements provided by the source [9] are indicated: 35 - water collecting pan and 36 - water measuring tank.

The downward flow of air can be replaced by the opposite upward flow. To this end, under pressure, air is supplied into the cavity of the patterns 20, and by discharge, air is removed from the cavity of the gallery 11.

After creating a downstream prism 8 of the air duct channel 33, the efficiency of separate activation of the cavities of both the gallery 11 and the lost 20 is increased, both when creating a downward flow and an upward flow.

The peculiarity of the operation and operation of a real dam in harsh climatic conditions is as follows.

1. In the initial period of operation, the dam has a significant, 2 meters or more, excess of the mark of the crest 13 of the core 2 over the normal retaining level of the NPU, the whole water pressure at which is perceived by the core 2. At a higher forced level, the FU includes the upper wall 14 of the gallery 11 .

In the cavity of the gallery 11, a positive temperature is maintained year-round, which prevents freezing of the upper part of the core 2, the state of which is monitored both visually and using measuring instruments.

2. In the warm season, the tip 9 of the dam acquires a heat reserve due to the increased, against the usual, absorption of solar heat (solar radiation) with an asphalt layer 26.

3. During the operation of the dam, freezing of the bottom prism 8 can exceed the permissible limits and create a threat of freezing of the bottom filters 5 and 6. In this case, through the previously indicated equipment, through the cavity of the gallery 11 and the cavity lost 20, forced movement of warm atmospheric air through a stone sketch of the bottom prism 8. As a result, the temperature boundary 32 is set at a safe distance from the core 2 with the formation of a highly permeable melt air duct 33, than and prevent freezing of the bottom filters 5 and 6 and partially the bottom prism 8.

4. When warm air is injected into the cavity of the gallery 11, the air ducts 16 direct the air into the stone outline of the head 9. Then, first, the air is laid with an asphalt layer 26, and then below the ASG layer 27 is directed downward along the stone outline of the bottom prism 8, while most of it moves to earth 20, in the cavity of which a vacuum is created. This is facilitated by the fact that, as a result of infiltration into the lower prism of atmospheric precipitation and negative temperatures in the rock outline, the pores fill up with ice over time, which reduces the air permeability of the frozen rock outline [10]. From the cavity lost 20, cooled air is sent to the atmosphere.

5. The equipment allows you to change the direction of the air flow and use the cavity of the gallery 11 and lost 20 together or separately, and the gate valves 17 and 22 of the gate (not shown) allow you to create air flow in a separate area and adjust its intensity. All this allows, if necessary, to control the air flow in the lower prism 8 over a wide range, up to the direction of the air flow along the dam.

6. The longline of the dam erected during the cold period of the year along its entire cross section is usually in a frozen state for several years (drawing). Ventilation of the lower prism with warm air accelerates the transfer of the dam from the frozen state to a more reliable melt state (except for the outer part of the lower prism). To accelerate this process through the air ducts 16 of the bottom wall 15 of the gallery 11 in the stone outline of the head 9 can be supplied with warm water, for example, from water pipes 19.

The invention allows to reduce the cost of creating a dam and increase its reliability by optimizing the temperature control of a stone-earth dam in the permafrost zone by ventilating the lower prism with atmospheric air during the warm season. However, for the successful reproduction of the proposed dam, it is necessary to carry out theoretical, theoretical, model and field studies.

The proposed technical solution can be implemented using well-known structural elements and technologies, which determines, according to the applicant, compliance with his criterion of "industrial applicability".

Information sources

1. Waterworks (in two parts). Part 1: Textbook for university students / Ed. Grishina M.M. - M .: Higher. School. 1979. S. 506-516.

2. Pekhtin V.A. On the safety of dams in the northern climatic zone // Hydrotechnical construction. 2004. No. 10.

3. Pekhtin V.A. Soil dam on permafrost. RF patent No. 2250296 dated 04/20/2005.

4. Yagin V.P. Soil dam on permafrost. RF patent No. 2309220 dated October 27, 2007.

5. Yagin V.P. Soil dam. RF patent No. 2207428 dated 06/27/2003.

6. Yagin V.P. Dam. USSR copyright certificate No. 1562391, priority of 11/10/1985, publ. 05/07/1990.

7. Yagin V.P. Dams from soil materials erected in the northern climatic zone // Hydrotechnical construction. 1997. No3.

8. Gorokhov Mikhail Evgenievich. Regulation of the temperature regime of stone-earth dams by controlling convection of air in the lower prism. Specialty: 05.23.07 - Hydrotechnical construction. Abstract of dissertation for the degree of candidate of technical sciences. Moscow - 2011.

9. Yagin V.P. Dam. USSR copyright certificate No. 1749360 of 07.23.92.

10. Mukhetdinov N.A., Okruzhnov S.V., Burlakov V.M. The dynamics of the temperature and humidity regime of the stone and earthen dam of the Vilyuiskaya HPP 1-2 in the operational period // Energy construction. 1999. No. 10.

Designations

1 - base

2 - core

3 and 4 - top filters

5 and 6 - bottom filters

7 - mount prism

8 - grassroots prism

9 - tip

10 - retaining wall

11 - gallery

12 - outrigger (galleries)

13 - core comb

14 - upper wall (galleries)

15 - bottom wall (galleries)

16 - air duct

17 - shutter

18 - grill

19 - water pipe

20 - lost

21 - air duct

22 - shutter

23 - grill

24 - dam crest

25 - downstream slope (dam)

26 - layer of asphalt

27 - layer ASG

28 - surface of the overflow part of the dam

29 - drainage

30 - tray (drainage)

31 - water pipe (in torn)

32 - temperature boundary (between thawed and frozen soils)

33 - air duct (thawed)

34 - air movement

35 - drainage tray

36 - water meter tank.

Claims (12)

1. A stone-earthen dam, the design of which is able to provide positive temperatures at the ridge and at the bottom of the core of the dam, erected in the northern climatic zone, is characterized by the fact that it has a core of clay soil, upper and lower transition zones from incoherent soil, top and bottom prisms, at least the bottom of which is made of stone outline, a head made of non-porous soil, a retaining wall of concrete, a layer of airtight material and equipment necessary for the ex lautation of the dam, while the tip of the dam accommodates a heated reinforced concrete gallery, between the outriggers of which there is a portion of the free surface of the ridge core, the retaining wall has a predetermined height, is located at the bottom of the dam on the lower side of the core and is waterproof to it and contains in its body non-flooded on the downstream side, the marks will be lost, and a layer of airtight material covers the crest of the dam and its bottom slope, at least within the height of the head, and the top the gallery wall is made waterproof, and the bottom wall of the gallery contains air ducts that provide hydraulic communication between the gallery cavity and the pore space of the stone outline of the head and the bottom prism, the retaining wall contains air ducts that provide hydraulic communication between the cavity and the pore space of the stone outline of the bottom prism in the place of its adjoining to the lower edge of the retaining wall, and the equipment is able to provide a compulsor through the gallery cavity and the cavity are lost the new movement of warm atmospheric air along the stone outline of the lower prism. 2. The dam according to claim 1, characterized in that the layer of airtight material has a dark color, and the value of its absorption coefficient of solar radiation (solar radiation, light) is not less than 0.8. 3. The dam according to claim 1, characterized in that it is equipped with hatches with closures capable of isolating the gallery cavity and / or cavity lost from direct communication with the atmosphere. 4. The dam according to claim 1, characterized in that it is equipped with devices, each of which is capable of blocking the gallery cavity or the cavity is lost. 5. The dam according to claim 1, characterized in that the predetermined number of air ducts from among those providing the hydraulic connection between the gallery cavity and the cavity are lost with the pore space of the stone outline are provided with shutters, each of which is installed at the entrance to the air duct from the side of the cavity. 6. The dam according to claim 1, characterized in that a drainage is made at the base of the lower prism, which is located along the retaining wall and is adjacent to it. 7. The dam according to claim 1, characterized in that the equipment is capable of supplying air to the gallery cavity by pressure. 8. The dam according to claim 1, characterized in that the equipment is capable of discharging air from the cavity by discharge. 9. The dam according to claim 1, characterized in that the equipment is capable of supplying pressure into the cavity by pressure. 10. The dam according to claim 1, characterized in that the equipment is capable of discharge to remove air from the gallery cavity. 11. The dam according to claim 2, characterized in that the layer is made of asphalt or asphalt concrete. 12. The dam according to claim 6, characterized in that the drainage is made on the lower edge of the retaining wall.

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