Method of draining flooded closed depressions

Abstract

FIELD: drainage.SUBSTANCE: invention relates to devices for draining surface water from closed, drainless depressions (saucers) and draining waterlogged and swampy soils. According to the invention, in the dry season, a trench 3 is dug from the lowest point 4 of the closed depression 2 to natural depressions in the area (narrow, ravines, hollows) or an artificial drainage and discharge channel 5. A perforated drainage pipe 6 wrapped with a thin-walled filter is laid with a slope from the central part of the closed depression to the open drainage and discharge channel 5 or to the natural depressions of the area. In the central part of the closed depression, a drainage water receiver 7 is installed, which is connected via a drainage pipe 6 to a drainage and discharge channel 5. Starting from the mouth, a small diameter pipeline 16, made hermetically sealed and waterproof, is placed inside the perforated drainage pipe 6. At the beginning of the pipeline 16 on the sun side, a suction vertical branch pipe 17 is installed with a hot-air temperature valve consisting of an elastic container 18 on which a disk 19 rests, and at the other end of the pipeline 16, an exhaust vertical branch pipe 20 is installed, the outlet of which is equipped with a deflector 21. In a closed depression 2 of the trench 3 before laying a multilayer filter 10, 11 12 in the central part above the drainage pipe 6, a filter in the form of a thin-walled horizontal plate 13 with longitudinal slots 14 is laid on top of the bedrock of the soil, which is covered from above with layers of at least two permeable geotextile fabric 15. The drainage pipe 6 is laid to a depth below the soil freezing layer for a given region. On top of the permeable geotextile fabric 15, a multilayer filter material in the form of gravel and coarse sand 10 is alternately placed, then sand 11 and the upper part of the trench 3 is covered with soil 12. The vertical suction pipe 17 with a hot-air temperature valve is covered from above with a light-permeable screen 23.EFFECT: drainage of surface water from field areas with closed, drainless depressions, and drainage of flooded and waterlogged heavy soils with low filtering capacity and close groundwater levels, unimpeded discharge of drainage water into an open discharge channel and year-round warm-air heating of the drainage pipe as well as earlier removal of excess moisture, which means that spring field work can be carried out earlier.4 cl, 2 dwg

Description

[0001] The invention relates to agricultural melioration and can be used to drain surface water from areas with closed, drainless depressions and drainage, flooded and waterlogged heavy soils with low filtering capacity, as well as with close groundwater levels and to ensure uninterrupted drainage operation during the winter period in ice-prone areas by year-round heating of the drain mouth using solar radiation.

[0002] A device for draining surface water is known, which includes a well buried in the soil and having a cover, communicating with a drain and equipped with perforated water-carrying pipelines located in depressions of the soil surface, each of which consists of a stationary part, hermetically secured with its lower end in the well cover, and removable sections connected to the stationary part with the possibility of changing both the number and the length of the removable sections depending on the level of surface water in the depression (Author's Certificate SU No. 1382909, E02B 11 / 00 dated 03 / 23 / 1988).

[0003] A disadvantage of this well-known device is its high operating costs due to the significant manual labor required for its maintenance. Furthermore, the presence of a drain does not protect the wellhead pipe from ice buildup and freezing of water within it, which prevents reliable operation in winter. This means the drain's operation and drainage effect are impaired, resulting in the wellhead becoming clogged with ice. The device also prevents warm air from reaching the end of the wellhead pipe during winter and early spring.

[0004] A surface water receiver is known, which includes a housing buried in the arable layer with a cover and water intake openings in it, while the side walls of the housing are made sloping with a variable slope coefficient, and in the lower part of the housing there is a branch pipe for draining water into a drainage network (Author's certificate SU No. 869790, E02B 11 / 00 dated 10 / 07 / 1981).

[0005] The disadvantage of this water intake system is its low efficiency due to the influx of contaminated water into the drainage system, which poses a risk of siltation and, consequently, a short service life. Furthermore, the device does not allow warm air to heat the end of the wellhead pipe, preventing ice buildup and freezing of water within it. This prevents reliable operation in winter, which means the drain and its drying action become blocked by ice plugs, and prevents warm air from heating the end of the wellhead pipe during winter and early spring.

[0006] It is known that when the air temperature is below freezing and the water flow from the drainage system is low, a winter low-water period occurs, and an icicle forms on the drainage system's outlet pipe. As a result of the influx of water, the icicle gradually increases in volume, clogging the cavity of the outlet pipe with an ice plug (Ignatok, F.V., "Closed Soil Drainage," Moscow: Kolos, 1965, pp. 36-37). As a result, the closed drainage system stops draining soil and groundwater. This cannot be allowed. It is known that in winter, under favorable conditions, closed drainage systems fed by atmospheric water discharge a small portion of the drainage flow volume. The formation of an ice plug in the outlet pipe at high drainage water flow rates is generally not observed.

[0007] The increase in the drainage of excess water in the winter period leads to an increase in the rate of formation of ice layers at the boundary of soil freezing and the rate of damage (erosion) of the root system of wintering plants, which does not contribute to earlier spring field work and high yields of cultivated crops.

[0008] A drainage system is known that includes a channel, a drainage collector, a well with holes, a filter column and a wellhead pipe that passes through the well and communicates with it through a recess in its upper part, made with lateral drains (Author's certificate SU No. 1427034, E02 B 11 / 00 dated 09 / 30 / 1988).

[0009] The well-known design of the drainage system provides for the mouth pipe to prevent the formation of an ice plug in it and ensures the smooth operation of the drainage system in winter.

[0010] A disadvantage of this device is that, with prolonged use, the bottom of the drainage well begins to gradually silt up with suspended soil particles. This is due to the fact that when water overflows through the spillway into the well, the flow rate through the holes in the bottom and the filter soil (filter column) drops sharply. The well itself can quickly fill with water, and its level can reach the spillway, which ultimately causes water backing up in the collector itself. At the same time, a buildup of ice forms at the end of the wellhead pipe, which means it becomes completely encased in ice, resulting in a delay in the collector's operation in the spring. Furthermore, overflow occurs over the top of the pipe, meaning the wellhead pipe itself becomes completely filled with water, creating a stagnant zone toward the collector.

[0011] A drainage system is known that includes drains, a collector, an open channel, a drainage well, from which a wellhead pipe with a valve comes out (Skripchiyskaya L.V. et al. “Agricultural hydraulic reclamation.” Kyiv, 1977, pp. 272, 343-344).

[0012] A disadvantage of this system is the delay in system startup in the spring due to ice plugs clogging the wellhead, the lack of automatic control when switching to "open" or "close," and the cessation of water discharge through the wellhead pipe. Furthermore, the system's design does not allow for heating the wellhead pipe to prevent ice plugs from forming.

[0013] A drainage system is known, including drains, a collector, and an open channel. A filter column is located in the channel slope, containing a wellhead pipe and a drainage well, with openings in the bottom and walls. The wellhead pipe and the collector in the drainage well are connected by a branch pipe, the lower part of which contains a drain hole with a valve (Author's Certificate SU No. 1366595, E02 B 11 / 00 dated January 15, 1988).

[0014] A disadvantage of this device is that the drain hole in the pipe opens with the onset of frost. This makes it difficult to determine the exact time of frost, which would require urgently closing the valve, limiting the time period when frosts occur. Furthermore, water stagnates in the drainage well itself due to poor filtration of the filter column, leading to overflow of the drainage well. This creates a backwater, and some water flows into the wellhead pipe, resulting in ice plugs at the wellhead. This, in turn, causes operational difficulties in determining when, in the spring, the valve must be manually closed again to initiate drainage earlier. This requires accelerated drying of the topsoil, which, in turn, should allow agricultural machinery to better prepare the fields for sowing within the optimal agronomic timeframe.The harvest of agricultural crops depends on these activities.

[0015] A method for draining closed depressions is known, containing an absorption well filled with filter material, vertical wells (Author's certificate SU No. 1169394, E02B 11 / 00 dated 02 / 29 / 1988).

[0016] A disadvantage of the known method is the removal of the topsoil from the depression surface, which leads to a decrease in soil fertility. Vertical wells filled with filter material are installed in a staggered pattern around the absorption well. These wells collect contaminated water from the closed depression and transfer it to the bedrock, which can be soils with high filtering properties. Water from the fields will contaminate the aquifers. Furthermore, the device is difficult to use, as solar heat can be used to heat the drainage outlet.

[0017] The closest in technical essence to the invention is a method for draining surface water from closed, drainless depressions (saucers) and draining waterlogged and swampy soils, containing unloading radial dead-end drains made from perforated pipes and equipped with air ducts combined with the atmosphere, a volumetric filter, a water-drainage pipeline, the above-ground part of which is wrapped with a thin-walled filter (Author's Certificate SU No. 1714036, E02 B 11 / 00 dated 02 / 23 / 1992).

[0018] A disadvantage of the known method of diverting surface water from closed endorheic depressions (saucers) and draining waterlogged and swampy soils is the high cost of materials and the need for construction work. Furthermore, its difficulty in use is also a drawback, as solar heat can be used to heat the drain mouths, and its use before the growing season has not been demonstrated.

[0019] The purpose of the invention is to develop a low-cost, simplified device for draining surface water from field plots with closed, drainless depressions and drainages, flooded and waterlogged heavy soils with low permeability, or with a close groundwater table. Furthermore, the design improves the operational design of the drainage drain mouth while maintaining the uninterrupted operation of the drainage system in winter and saturates them with warm air during the winter and early spring before the onset of summer.

[0020] The technical result of the invention is a new property, namely: the possibility of year-round hot-air heating of the mouth operation, ensuring an earlier start of drainage, which will allow agricultural machinery to better prepare fields for sowing, and complete sowing in optimal agrotechnical terms to increase the yield of agricultural crops grown on lands when water accumulates during the cold period of the year and leads to the death of winter crops, perennial grasses, and also delays spring field work.

[0021] The technical result is achieved in that the method for draining flooded closed depressions, including laying a perforated drainage pipe wrapped with a thin-walled filter, filling a trench in a depression with a filter material that includes a layer of gravel or coarse sand throughout the trench, on top of which a layer of sand and then soil is poured, according to the invention, is torn off in the dry season from the lowest place of the closed depression to natural depressions of the area or an artificial drainage and discharge channel, a drainage perforated pipe wrapped with a thin-walled filter is laid from the central part of the closed depression to an open drainage and discharge channel or to natural depressions of the area, in addition, starting from the mouth inside the perforated drainage pipe, a small-diameter pipeline is placed, made hermetically sealed and waterproof,in this case, from the mouth side at the beginning of the small diameter pipeline on the sun side, a suction vertical branch pipe with a warm-air temperature valve is installed, covered in the upper part with a translucent screen, and at the other end of the small diameter pipeline, an exhaust vertical branch pipe is installed and its outlet is equipped with a deflector, in addition, part of the trench in the depression from the central part of the closed depression is made a drainage water receiver, in the form of backfill with a filter material consisting of a layer of gravel or coarse sand, on top of which a layer of sand and then soil is poured along the depth of the drainage water receiver, while above the laying of the drainage pipe on the bedrock, a filter is laid in the central part of the bottom of the depression in the form of a thin-walled horizontal slab, which is a lattice slab with longitudinal slots, which is covered with the first layer, filter material, including at least two layers of permeable geotextile fabric,Moreover, the depth of the drainage pipe in the lowest point of the closed depression must be lower than the depth of soil freezing for the given area, so that water drainage can be carried out during the cold season, without interfering with plowing and crop care work.

[0022] In addition, the lower end of the vertical pipe is connected together with the laid perforated drainage pipe.

[0023] In addition, the suction vertical pipe from the mouth side in the upper part is made with air passage holes, at least two, in the side wall to admit additional warm air.

[0024] In addition, the suction vertical pipe in the drainage and discharge channel is connected to the channel slope by means of a fastening rod, the upper part of which is covered with a protective plate above the mouth of the perforated drainage pipe.

[0025] The invention is illustrated by a drawing: where Fig. 1 shows a diagram of a device for draining water from a closed depression and a diagram of the location of a heat-conducting pipeline at a high groundwater level; Fig. 2 shows a fragment in plan of a horizontal floor slab made in the form of a lattice slab with longitudinal slots.

[0026] The diagram shows: accumulated surface water 1 in a closed depression 2, a trench 3, the lowest point of the closed depression 4, natural depressions of the terrain (ravines, ravines, hollows) or an artificial drainage - discharge channel 5, a drainage pipe 6 wrapped with a thin-walled filter, part of the trench in the depression is arranged towards the mouth of the drainage water intake 7, connected by means of a drainage pipe 6 with a drainage - discharge channel 5, one wall 8 of which slope on the sun side has a fastening plate 9. The drainage water intake 7 is made by backfilling with a multi-layer filter material: the middle part with gravel or coarse sand 10, and the upper part with sand 11 and soil 12. In addition, below the arable layer above the drainage pipe 6, a thin-walled floor slab is laid on the bedrock, which is lattice plate 13 with longitudinal through slots 14.The lattice plate 13 with longitudinal through slits 14 is covered with the first layer from above, at least two, with a layer of water-permeable geotextile fabric 15, through which water from melt and rainfall then flows down through the filter layer along the depth of the trench into the inside of the drainage pipe, the upper part of which is filled with filter material from gravel or coarse sand 10, sand 11 and soil 12. The middle layer of the filter consists of coarse sand 10 (or gravel) with a thickness of 30-35 cm, the upper layer of sand 11 with a thickness of 35-40 cm, and a layer of soil 12 is filled with removed arable layer, with a thickness of 20-25 cm, without preventing the shift of the first (lower) row of the layer of geotextile material 15, laid on top of the lattice plate 13 with longitudinal slits 14, and other work on the care of agricultural crops.

[0027] This is how you can build a water-draining structure and remove quickly accumulated moisture from a closed depression.

[0028] The mouth on the side of the drainage and discharge channel 5 with the drainage pipe 6 at the end of which is additionally placed inside the underground drainage pipe 6, laid with a slope to the horizontal at the end, towards the drainage and discharge channel 5 and which is located at a high groundwater level, on the side of the sun of a small pipeline 16 of small diameter, made sealed and waterproof, which is also laid with a slope to the horizontal at the end. In this case, at the beginning of the end of the small diameter pipeline 16, from the mouth side, a suction vertical branch pipe 17 is installed with a hot-air temperature valve consisting of an elastic container 18, on which a disk 19 rests, and the body of the branch pipe 17 is reinforced together with the fastening plate 9 with the wall of the slope 8 of the discharge channel 5. At the other end of the small diameter pipeline 16, an exhaust vertical branch pipe 20 is installed, connected to the walls of the drainage pipe 6.The outlet of the exhaust pipe 20, connected hermetically to the small diameter pipeline 16, is provided with a deflector 21, and in the walls of the suction vertical pipe 17, air passage holes 22 are additionally made. The entire suction pipe 17 and part of the discharge channel 5 are closed from above with a translucent screen 23.At the junction of the suction pipe 17 with the air-passing opening 22 with a hot-air temperature valve consisting of an elastic container 18 and a disk 19, air is heated from the sunny side, which does not allow the formation of an ice build-up 24 at the very end of the mouth of the drainage pipe 6, and which creates a backwater of water, which is the beginning of the mouth pipe, in the winter period with small water flows, as well as during the period of winter floods, it is heated due to the creation of air heating by the sun, which rises along the small diameter of the pipeline 16, located inside the drainage pipe 6 towards the deflector 21 of the exhaust pipe 20 and draws heated air from the pipeline 16.

[0029] It should be noted that on a sunny day, the air under the translucent screen 23 is heated due to the increased heating surface with the mounting plate 9 with the soil slope 8, as well as due to the angle (about 45 degrees, when the sun is high above the horizon) of the heating surface inclination to the sun's rays. When the sun is low (February, March), a strip (not shown, for example, made of dark-colored plastic boards) is installed vertically under the translucent screen 23 at a large angle of inclination (from 45 to 90 degrees or more). The set air heating temperature at the suction pipe 17, located under the translucent screen 23, is calculated and depends on the area under the translucent screen 23, on the diameter of the opening and its configuration, the length and slope of the drainage pipe 6 and the small diameter of the pipeline 16, as well as on the existing soil temperature beneath the soil.As noted above, the heated air under the translucent screen 23 creates pressure, enters the cavity of the small pipeline 16, and moves along it, transferring heat to the walls of the drainage pipe 6 and the soil to accelerate the air movement in the cavity of the small pipeline 16. At the outlet, an exhaust pipe 20, consisting of a deflector 21 on top, is hermetically inserted into the opening of the small pipeline 16. In this case, the exhaust pipe 20, through which the accelerating air is released, creates the effect of a "water jet pump". The speed of movement of the heated air in the cavity of the pipeline 16, and therefore the heat exchange between the pipe body 6 and the filter layers, can be regulated by closing or opening the air vents 22 or by blocking the pipe of the exhaust pipe 20. In addition, heat affects not only the removal of ice buildup 24 at the end of the drainage pipe, but also the heating of the filter from above above the drainage pipe 6, and most of the length of the latter.

[0030] This design solution makes the device simple overall.

[0031] Example 1. Water from melt water and rainfall flows into a closed depression 2 and water 1 accumulates, flooding the surface, through a filter substrate 10, 11, 12 and a permeable geotextile material 15, then through a lattice plate 13 with longitudinal slots 14 it seeps down towards the drainage water receiver 7 to the drainage pipe 6 and is diverted into natural depressions or a drainage and discharge channel 5.

[0032] Calculation of the dimensions of the backfill with gravel or coarse sand with soil of the drainage water intake 7 is determined depending on the volume of the diverted part of the water (Q B , m 3) in a closed depression plus the volume of water from water-saturated soil to drain the topsoil to a depth of 1 m, the absorption rate of the geotextile filter material, at least two rows, then through the longitudinal slots of the intake slab, and through the filter of gravel, sand, and soil above the drain. Calculations are performed using known hydraulic methods, which take into account S yч - area of ​​the flooded closed depression (m 2 ); N з.п. - average water depth in the flooded depression (m); H уч . - the area of ​​the site for water drainage in a 1 m layer, under the flooded section of the drainage water intake plus adjacent waterlogged areas (S пp ), requiring drainage and bringing moisture reserves from 0.8 to 0.9 HB in a 1 m layer.

[0033] Example 2. The accumulation of water depends on the slope of the soil surface, for example, the area will be (water drainage area) H уч .=3×S yч ., where S yч- flooded area. Then we have the water reserve in the soil in the upper saturated layer of 1.0 m, and the amount that needs to be drained is determined by formula 3 в.п. = ППВ-(0.85-0.9)НВ, where ППВ is the total field moisture capacity (taken from a reference book or determined experimentally), m3 / ha; НВ is the smallest moisture capacity (taken from reference books or determined experimentally), m3 3 / ha; (0.85-0.9) - coefficient of the lower moisture threshold, equal to (0.85-0.9)HB.

[0034] Observations show that for a certain soil, in order to prevent the destruction of grain crops (winter crops) during the spring (cold) period, flooding should not exceed 10-15 days.

[0035] The dimensions of the layers of filtering surface materials made of gotextile, overlapping the lattice plate with longitudinal slots, are based on the fact that the thickness of the material is a thin fabric material with a density of 100 g / m 2 , thicker material with a density of 600 g / m 2It is made from environmentally friendly polymer materials. The rough surface of the geogrid-like material creates a certain resistance to the cell walls.

[0036] The use of permeable geotextile drainage sheets placed over a grid plate with longitudinal slots during production for filtration along the contour of the filter inlet provides flexibility and ductility, support, and excellent water intake and filtration properties. It is simple, cost-effective, odorless, and highly durable, with a service life of at least 30 years. The structure is rot-resistant and is impervious to moisture, heat, frost, and sunlight. Geotextile sheets are a new material, widely manufactured both domestically and internationally.

[0037] Example 3. The absorption rate inside a drainage inlet filled with sand (K) water absorption filter material in 1 hour can range from 500 to 1500 mm / hour. Translated as 1 ha = 5000 m 3 / ha in 1 hour it is possible to skip (according to calculation) 0.5 m 3 / (m 2 ⋅h). The backfill area is also related to the device with a covering area on top of a lattice slab 13 with longitudinal through-cuts 14 for support on the bedrock of the soil and a permeable material made of geotextile and a filter laid on top of it.

[0038] Therefore, without providing here all the hydraulic calculations according to the known formulas of hydromelioration, we note that with a water velocity in the drainage pipe of 0.2 m / s, we have the diameter of the drainage pipe: Thus, to drain water from a closed depression (for a period of 15 days) with a volume of approximately 8000 m, the pipe diameter in practice will be 100 mm, which can be washed when they become silted up. In addition, the diameter of the pipes can vary, or several drainage pipes are laid in parallel (for example, two drainage pipes laid side by side).

[0039] The condition for the absence of ice buildup (in the form of a plug) only if there is a drainage pipe 6 at its end is the purpose of the pipe mouth design (from freezing), when a sunny day is used and the air under the translucent screen 23 is heated due to the increased heating surface, i.e., depending on the state in the direction of the sun's rays. The specified air heating temperature at the suction pipe 17, located under the translucent screen 23, is calculated and depends on the area under the translucent screen 23 and the diameter of the suction pipe 17 with the air passage opening 22 and its configuration, as well as on the existing soil temperature beneath.

[0040] Heated air under the translucent screen 23 creates pressure, enters the small-diameter cavity of the pipeline 16 located inside the drainage pipe 6 and moves along it, giving off heat to the walls of the drainage pipe 6, as well as heat to the soil layer with a positive temperature that remains constant throughout the season. In general, this does not allow the multilayer filter to freeze, due to which the accumulated water from autumn, winter and early spring precipitation freely penetrates through the layers of the filter 10, 11, 12 and the geotextile 15, as well as through the lattice plate 13, is filtered, enters the pipe 6, and exits into the drainage and discharge channel 5. To accelerate the air movement in the small-diameter cavity of the pipeline 16, an exhaust vertical pipe 20 with a deflector 21 is inserted (connected) at the upward outlet.

[0041] The speed of movement of heated air through the small diameter pipeline 16, and, consequently, the heat exchange of the drainage pipe 6 in the ground, can be regulated by closing or opening the exhaust pipe 20.

[0042] In the spring, with the onset of snow melting, the drainage flow increases, and the water pressure in pipe 6 increases, the throughput also increases, which facilitates the free flow of water into the drainage and discharge channel 5. Ice build-up 24 (in the form of a plug) is absent at the end of the mouth of the drainage pipe 6, since warm air constantly enters from the outside into the small diameter of the pipeline 16.

[0043] This design solution will expand the functionality, make the device simple, adjustable and effective in conditions of frozen soil, and therefore is a prerequisite for obtaining higher yields of agricultural crops.

Claims

1. A method for draining flooded closed depressions, which includes laying a perforated drainage pipe wrapped with a thin-walled filter, filling a trench in the depression with a filter material, which includes a layer of gravel or coarse sand throughout the trench, on top of which a layer of sand and then soil is poured, characterized in that the trench is dug in the dry season from the lowest point of the closed depression to natural depressions of the area or an artificial drainage and discharge channel, the perforated drainage pipe, wrapped with a thin-walled filter, is laid from the central part of the closed depression to an open drainage and discharge channel or to natural depressions of the area, in addition, starting from the mouth, a small-diameter pipeline made hermetically sealed and waterproof is placed inside the perforated drainage pipe,in this case, from the mouth side at the beginning of the small diameter pipeline on the sun side, a suction vertical branch pipe with a warm-air temperature valve is installed, covered in the upper part with a translucent screen, and at the other end of the small diameter pipeline, an exhaust vertical branch pipe is installed and its outlet is equipped with a deflector, in addition, part of the trench in the depression from the central part of the closed depression is made a drainage water receiver in the form of backfill with filter material consisting of a layer of gravel or coarse sand, on top of which a layer of sand and then soil is poured along the depth of the drainage water receiver, while above the laying of the drainage pipe on the bedrock, a filter is laid in the central part of the bottom of the depression in the form of a thin-walled horizontal slab, which is a lattice slab with longitudinal slots, which is covered with the first layer of filter material, including at least two layers of permeable geotextile fabric,Moreover, the depth of the drainage pipe at the lowest point of the closed depression must be lower than the depth of soil freezing for the given area, so that water drainage can be carried out even during the cold season, without interfering with plowing and crop care work.

2. The method according to paragraph 1, characterized in that the lower end of the vertical branch pipe is connected together with the laid perforated drainage pipe.

3. The method according to paragraph 1, characterized in that the suction vertical branch pipe on the mouth side in the upper part is made with air passage holes, at least two, in the side wall for the admission of additional warm air.

4. The method according to paragraph 1, characterized in that the vertical suction branch pipe in the drainage and discharge channel is connected by means of a fastening rod to the slope of the channel, the upper part of which is covered with a protective plate above the mouth of the perforated drainage pipe.

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