RU2392376C1 - Hydrotechnical channel under conditions of permafrost soils of slope - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: channel comprises bed formed by bottom of channel and slopes of its boards and frost screen made of ice ground in bottom board of channel. With the help of upper and lower structure channel is joined with watercourse. Channel is equipped with two pipes arranged along channel near its bottom and covered by ground. One pipe is coated with heat-insulating material, within the limits of upper structure it is provided with water-receiving socket, and provides for watercourse water passage in volume corresponding to the beginning of cold season of the year. Other pipe is equipped with perforation, is enclosed into filtering material, is hydraulically joined to seasonally thawing layer of slope, and in cold season of the year it provides for drain of seasonally thawing layer of water, which may form ice crust in channel. Upper structure comprises water-lifting dam that obstructs watercourse and entrance head equipped with overflow weir, every of which with the help of frost curtain created by seasonal cooling devices is joined with permafrost soils in a water impermeable manner. Upper structure delivers water from watercourse into channel and into water-receiving socket of pipe. In case the channel is deepened into permafrost soils of slope, the first pipe adjoins bottom side of channel, and the second one - to upper one. In case channel bed is arranged over seasonal thawing layer of slope, both pipes are located nearby and adjoin bottom side of channel.

EFFECT: increased reliability of channel as a result of reduced thermal effect of water flow at bottom and side of channel and prevention of ice crust formation in channel.

5 cl, 6 dwg, 2 ex

Description

The invention relates to hydraulic engineering, and more specifically to the construction of channels on permafrost slope soils that have vein ice at the surface of the slope and periodically occurring deep ice cracks unfilled with ice, in particular, when creating a channel bypassing the industrial waste storage.

A hydraulic channel is known in conditions of permafrost soils of the slope, which discharges surface runoff water from a protected mountain object and contains a bed formed by the bottom and slopes of the sides of the canal buried in permafrost soils of the slope, and a frozen curtain made of ice ground in the downstream side of the slope channel. Through the upper and lower structures, the canal is interfaced with a watercourse [1, 2].

The disadvantages of the known channel are as follows.

1. In the permafrost zone during cooling during unilateral freezing of soils from above, occurring under conditions of continuous penetration of precipitation water into the frost-cracked and pores of the soil below the seasonal thawing of soils within the weathering crust, waterproof ice-crusted ice-crust (raincoat) was formed almost everywhere. Under this frozen crust, up to now, individual hollow stress cracks have been preserved, according to which in previous periods of freezing under the influence of slopes, water flowed out from under similar frozen crusts to the nearest discharge sites [3].

When performing the channel, the integrity of the frozen crust is often disturbed in places, which leads to the development of intensive filtration of water from the channel and, accordingly, an abnormally fast thawing of permafrost soils. This leads to unacceptable deformations of the canal, and water filtering from the canal in an unacceptable volume, often in the form of a breakthrough, flows into the protected mountain object: the tailing pond of the Nadezhda Metallurgical Plant in Norilsk [1], tailing pond No. 8 in the village of Aikhal in Yakutia and others.

2. The ice formed during the autumn-winter freezing on the slope of the seasonal thawing layer fills the canal from the side of its upper side, which prevents the freezing of the soils that form the canal, and complicates the passage of spring flood waters through the canal.

These shortcomings of the known channel cause its lack of reliability during operation. In this case, the shielding of the channel bed, for example, with polymer roll material is associated with high costs for performing a screen with valves and an anti-slip device.

In the case of the implementation of the channel in the embankment [4], the volume of earthwork increases, therefore, the cost. The reliability of such a channel may also be insufficient due to the thermal effect of water on the bottom and sides of the channel. At the same time, the flow of water prevents the intensive freezing of the soils forming the channel in the first half of the cold season, when the soils are not yet covered with a thick layer of snow.

The task, which is aimed by the claimed hydraulic channel, is to increase the reliability of the channel. The technical result achieved during the implementation of the invention is that in the cold (autumn-winter) period of the year, the thermal effect of the water flow on the bottom and sides of the channel is reduced and the formation of ice in the channel is prevented.

This problem is solved, and the technical result is achieved by the fact that in the hydraulic channel under conditions of permafrost soils of a slope containing a bed formed by the bottom of the channel and the slopes of its sides, a frozen curtain made of ice ground in the lower side of the channel relative to the slope, while the channel through the upper and lower structures is connected with the watercourse, according to the invention, the channel is equipped with two pipes located along the channel at its bottom and covered with soil. One pipe, of the two, is covered with heat-insulating material, is equipped with a water inlet within the upper structure and ensures water passage of the watercourse, at least in the amount of the beginning of the cold season. Another pipe is provided with perforation, enclosed in filtering material, hydraulically connected to the seasonally spreading layer of the slope and provides in the cold season the water can be drained from the seasonally spreading layer, which can form ice in the channel.

Additionally:

- the upper structure contains a water-lifting dam blocking the watercourse, and an inlet head equipped with a spillway threshold, while the upper structure directs water from the watercourse to the canal and the water inlet of the pipe, and the water-lifting dam and inlet head, each by means of permafrost curtains created by seasonal cooling devices waterproof mating with permafrost soils;

- in the case of deepening the channel into permafrost soils of the slope, the first pipe adjoins the lower side of the channel, and the second - to the upper;

- in the case of the channel bed over the seasonally spreading layer of the slope, both pipes are located nearby and are adjacent to the lower side of the channel;

- the permafrost curtain of the inlet head is created by means of a seasonally acting cooling device (SOU) with curved cooling pipes.

It is the passage of water of a watercourse through a thermally insulated pipe that reduces the thermal effect of the water flow on the soils of the channel bed during the most important initial period of freezing, when the soils are not yet covered with a thick layer of snow. At the same time, the removal of a perforated pipe from the seasonally flowing layer of the water slope prevents the formation of ice in the channel, which prevents the soil from freezing through the channel bed and complicates the passage through the spring flood channel. All this provides a solution to the problem and obtaining the previously specified technical result.

The authors are not aware of technical solutions containing a combination of features identical to the claimed one, which allows us to conclude that the proposed invention meets the criterion of "novelty." The given information, according to the authors, also confirms the compliance of the claimed invention with the criterion of "inventive step".

The invention is illustrated by drawings:

- figure 1 shows the hydraulic channel, bypassing the tailings in the conditions of permafrost slope soils, a schematic plan;

- figure 2 is a section aa in figure 1, a cross section of the channel, example 1;

- figure 3 - node I in figure 1, the plan of the horse structure;

- figure 4 is a section bB in figure 3, a section along the input end along the stream;

- figure 5 is a section CC in figure 3, a section along the inlet head across the stream;

- figure 6 is a section aa in figure 1, a cross section of the channel, example 2.

Example 1 (FIGS. 1-5)

Channel 1 (hereinafter: the channel) is an artificial channel of a seasonal watercourse 2 laid bypassing a functioning or decommissioned “typical” bulk gully-ravine tailing dump (sludge storage) 3, the soil capacity of which is formed by a channel dam 4 and a water-lifting dam 5, creating the same regulating capacity 6 on the watercourse 2. The tailing pond 3 is protected from surface runoff from the left-bank slope 7 by a ditch ditch 8, and from the right-bank slope 9 directly scarlet. The channel is interfaced with a watercourse 2 by means of an upper structure 10, including a water-lifting dam 5, and a lower structure, made in the form of a fast current 11.

The channel is buried in the permafrost soils of slope 9, is made in a semi-half-dredge and has a trapezoidal cross section. The channel includes a development 12, creating the bottom 13 of the channel and its horse, with respect to the slope 9, the side 14 with the uphill slope 15 of the channel, as well as the embankment 16, creating the downhill 17 with the bottom slope of the 18 channel. The lower side 17 of embankment 16 is frozen and it forms an ice-ground permafrost curtain 19, conjugated with permafrost soils of the right-bank slope 9. The bottom 13, the upper slope 15 and the lower slope 18 are all covered with a protective layer 20 made of incoherent filtering soil of a given grain composition, for example gravelly sand, and forming a channel bed. In addition, the channel is equipped with two pipes 21 and 22 located along the channel at its bottom 13 and covered with soil similar to the soil of the protective layer 20. The pipe 21 adjoins the lower side 17, is covered with a heat-insulating layer 23 made, for example, of their polystyrene foam, within the upper building 10 is equipped with a water intake bell 24 and provides water passage of the watercourse, at least in the volume of the beginning of the cold period of the year - a period of stable negative outside temperatures. The pipe 22 is adjacent to the upper board 14, provided with perforations, enclosed in a filter 25, by means of a protective layer 20 is hydraulically connected to the seasonally spreading layer 26 of slope 9 and provides for the removal of water from the seasonally spreading layer 26, which can form ice in the channel during the cold season.

The upper structure 10 comprises a water-lifting dam 5 made of soil materials and blocking the watercourse 2, and an inlet head 27 made of concrete and equipped with a spillway threshold 28. The water-lifting dam 5 and the inlet head 27 are each by means of a permafrost curtain 29 created by seasonal-acting cooling devices (СОУ ) 30 and 31, watertightly interfaced with permafrost soils. СОУ 30 contain vertical cooling pipes [5], and СОУ 31 - curved cooling pipes [6].

In the drawings, additional items indicate:

32 - moisturizing ditch;

33 - frozen crust (cloak);

34 - maximum water level;

35 - a viewing well;

36 - inspection pipe;

37 - input head tooth;

38 - an arrow indicating the direction of movement of water in the seasonally spreading layer;

39 - geomembrane (polymer film);

40 - mounting plate.

A feature of the creation of the channel is that, firstly, the bottom board 17 is frozen mainly by direct exposure to cold atmospheric air while moistening this side 17, for example, by means of a humidifying ditch 32, and secondly, the channel is fully prepared to withstand at least one cold season. The latter condition is necessary both for deep freezing of the bottom side 17 and for the restoration of the frozen crust 33, the water resistance of which could be impaired by the production of 12.

Excavation 12 changes the stress state of rocks mainly due to the fact that the upper layer of rocks, opened by excavation 12 and forming the bottom 13 of the channel, is first subjected to annual temperature fluctuations, which are many times higher than its previous household temperature fluctuations in its entire history. As a result, in the cold season, under the influence of temperature stresses in the rocks, existing cracks open and new cracks form. Typically, the formation of such cracks occurs within the frozen crust 33, which is not dangerous in the cold season before starting the operation of the channel, since the waterproofness of the frozen crust is quickly restored.

The mechanism for restoring the water tightness of the frozen crust 33 in the cold season before the first summer period of the channel’s operation is that water from the seasonally transmitting layer 26, without pressure, enters a hollow crack, where the water freezes in accordance with the heat balance and, therefore, forever fills a hollow crack the so-called re-vein ice.

The channel works as follows.

In the warm season, the permafrost curtain 19 of the bottom side 17 and the frozen crust 33 restored at the bottom 13, which were restored during the period of exposure, prevent the filtering of water from the channel around the entire perimeter of its live section. The water of the summer low water, heated in the regulating tank 6, enters the water intake socket 24 and moves only through the heat-insulated pipe 21, therefore there is no intensive movement of this water along the bottom 13 in the channel, which reduces the thawing rate in the frozen soil channel. Water that has spilled over the spillway threshold 28 of the inlet head 27 moves directly along the channel into the floods, usually for a short time and not more than 50-70 days, which is not dangerous.

In the cold season, all the water from the control tank 6 moves only through the heat-insulated pipe 21, and the water 38 from the seasonally flowing layer 26 of the right-bank slope 9, which can form ice in the channel, enters the perforated pipe 22 and is discharged into the watercourse 2 below the channel dam in rapid flow 11 4. This prevents the formation of ice in the channel, which is able to substantially prevent the freezing of the soil forming the channel and, therefore, is able to prevent the restoration of water resistance of the frozen crust 33 in the channel and is capable of skipping the channel complicate spring flood water.

The channel created in this way is economical and reliable. In the channel, the previously indicated technical result is fully achieved.

Example 2 (Fig.6)

The main difference between the channel and the one described in Example 1 is that the entire channel bed is located above the day surface 41 of slope 9, i.e. above the seasonally spreading layer 26. In such a channel, the lower side is formed by embankment 42, the upper side of the channel is partially or completely formed by day surface 41 of slope 9, and both pipes 21 and 22 are adjacent and adjoin embankment 42.

When executing the channel there is no violation of the integrity of the frozen crust 33, which increases the reliability of the channel during operation. Therefore, despite the increase in the volume of earthwork during the construction of embankment 42, under favorable local conditions, the creation of such a channel may be appropriate.

When implementing the claimed invention, the conditions of "industrial applicability" are fulfilled. Means embodying the invention in its implementation are intended for use in industry, namely in hydraulic construction; the possibility of carrying out the invention using the described or other means and methods known prior to the filing date of the application is confirmed; means embodying the invention in its implementation, are able to provide the specified technical result.

Information sources

1. Yagin V.P., Vaikum V.A., Povarenkin V.A., Davydov I.A., Neyland N.N. On the issue of placement of solid water-containing wastes of thermal power plants and other industries // Hydrotechnical construction. 1998. No. 6.

2. Hydraulic structures of the tailings of the NMZ. The second phase of construction. Drainage system. Drawings: No. 166-13-3, No. 166-13-15. Krasnoyarsk: Hydroproject, 1987.

3. Yagin V.P., Vaikum V.A. The basic hydrogeological scheme is the hypothesis of permafrost, taking into account the history of geocryological development of the territory and with regard to hydraulic engineering construction. Intellectual product. FGUP VNTIC is registered under the number 73200700080.

4. Waterworks: Textbook. for universities: In 2 hours, Part 2 / L.N. Rasskazov, V.G. Orekhov, Yu.P. Pravdivtsev and others; Ed. L.N. Rasskazova. - M: Stroyizdat, 1996.P.227, Fig. 26.9, d.

5. Building regulations. Dams from soil materials (SNiP 2.06.05-84) / Gosstroy of the USSR. - M: TsITP Gosstroy USSR, 1989. Damn 2.1.

6. Guidance on the design, construction and operation of artificial structures of roads on watercourses with ice / Voronezh Ing. builds, in. M .: Transport, 1989.P. 4.27, Fig. 18 and Appendix 9.

Designations

1 - channel

2 - watercourse

3 - tailing pond

4 - channel dam

5 - water-lifting dam

6 - regulating capacity

7 - left-bank slope

8 - upland ditch

9 - right bank slope

10 - horse structure (mating)

11 - rapid flow (lower construction)

12 - production

13 - bottom (channel)

14 - horse board (channel)

15 - riding slope

16 - embankment

17 - lower side (channel)

18 - downhill slope

19 - permafrost curtain (bottom board)

20 - protective layer

21 - pipe (thermally insulated)

22 - pipe (perforated)

23 - thermal insulation layer

24 - water intake bell

25 - filter

26 - seasonally spreading layer

27 - input tip

28 - overflow threshold

29 - permafrost curtain

30 - SOU with vertical cooling pipes

31 - SOU with curved cooling pipes

32 - moisturizing ditch

33 - frozen crust (cloak)

34 - maximum water level

35 - manhole

36 - inspection pipe

37 - input head tooth

38 - an arrow indicating the movement of water in the seasonally spreading layer

39 - geomembrane (polymer film)

40 - mounting plates

Example 2:

41 - day surface (slope)

42 - embankment

Claims (5)

1. The hydraulic channel in the conditions of permafrost soils of the slope, containing a bed formed by the bottom of the channel and the slopes of its sides, a frozen curtain made of ice in the lower side of the channel relative to the slope, while the channel through the top and bottom structures is connected to a watercourse, characterized in that it is equipped with two pipes located along the channel at its bottom and covered with soil, while one pipe is covered with heat-insulating material, equipped with a water-intake bell and a weight within the upper structure bakes the water passage of the watercourse at least in the volume of the beginning of the cold season, and the other pipe is provided with perforations, enclosed in filter material, hydraulically connected to the seasonally spreading layer of the slope and provides during the cold season the water can be drained from the seasonally flowing layer, which can form ice . 2. The channel according to claim 1, characterized in that the upper structure comprises a water-lifting dam blocking the watercourse and an inlet head equipped with a spillway threshold, while the upper structure directs water from the watercourse to the canal and to the pipe inlet, and the water-lifting dam and inlet the head, each by means of a permafrost curtain created by seasonally acting cooling devices, is waterproofly interfaced with permafrost soils. 3. The channel according to claim 1, characterized in that in the case of deepening the channel into permafrost soils of the slope, the first pipe is adjacent to the lower side of the channel, and the second to the upper. 4. The channel according to claim 1, characterized in that in the case of the channel bed above the seasonally spreading layer of the slope, both pipes are adjacent and adjacent to the lower side of the channel. 5. The channel according to claim 2, characterized in that the permafrost of the inlet head is created by means of a seasonally acting cooling device (SDA) with curved cooling pipes.

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