RU2449078C2 - Method to erect erosion-preventive structure of biopositive design - Google Patents

Abstract

FIELD: construction, road engineering.

SUBSTANCE: invention relates to hydraulic engineering and nature conservation construction, and may be used as erosion-preventive structures used in piedmont and mountain areas of protected natural reserves. The method includes erection of a multi-stage drop. Structure stages are arranged in the form of bottom thresholds from rows of heavy fascines of biopositive design. Thresholds are laid across a channel and normally to direction of surface water flow. Thresholds from heavy fascines are arranged at a certain distance from each other along the entire washed section of the ravine, and are made of three or more rows laid tightly into a horizontal layer of heavy fascines. Along coastal slopes of the ravine above the fascine thresholds, light fascines are laid in parallel rows as one layer to the level of the matted ground surface and in direction of the water flow. A gabion net is tightened on top of the light fascines and is attached to slopes and to a metal net of heavy fascines.

EFFECT: higher efficiency of structure operation and recovery of ravines and other washed sections of eroded lands.

5 dwg

Description

The invention relates to hydraulic engineering and environmental construction and can be used to restore gullies and other eroded zones in the foothills and mountains of protected natural areas.

Known anti-erosion structure, made in the form of rapid flow, consisting of twigs, wooden stakes, stone and soil [1, p. 65-68]. The main disadvantages of this structure are the low efficiency and service life of the structure. Firewood and wood elements of the structure within a short period (3-5 years) rot and collapse. In addition, such a structure can only be used with a peak gully drop of up to 2 m.

Anti-erosion structures are also known, made in the form of a delta, consisting of reinforced concrete, stone, fascia steps [1, p. 73-75]. The main disadvantages of these technical solutions are the low efficiency and biopositiveness of the structure, as well as the high material consumption of the structure.

The purpose of the invention is to increase the efficiency of the structure and the biopositiveness of the structure and reduce material consumption.

This goal is achieved by the fact that in the method of erecting an anti-erosion structure, including a multi-stage drop, the steps of the structure are arranged in the form of bottom thresholds from the rows of heavy fascines of a biopositive structure, which are laid across the channel and normal to the direction of the surface water flow, thresholds from heavy fascines are placed at a certain distance from each other throughout the eroded section of the ravine, and consist of three or more rows densely laid in a horizontal layer of heavy fascines, and along the coastal open ravine wasps above the top of the fascin thresholds in parallel rows in one layer to the level of the sodded surface of the earth and in the direction of the water flow light fascines are laid, on top of which they tighten the gabion net and attach it to the slopes and to the metal net of heavy fascines.

Figure 1 shows a cross section of an erosion control structure along the axis of the strip of rows of heavy fascines; figure 2 is the same in plan; figure 3 shows a longitudinal section along the axis of the structure; figure 4 - heavy fascia with a cut in a perspective view; figure 5 is a light fascin of reeds.

The erosion control structure consists of heavy and light chutes of a biopositive structure combined in a ravine from the erosion line 1 to the level of the sodded surface of the earth 2. Heavy chutes 3 are made of soil aggregate and flexible shells, while the filler is made of bags 4 filled with fertile soil with the addition of seeds of perennial grasses and shrubs, and the shell of heavy fascia is made up of a dense layer of light fascia 5 and a flexible gabion net 6, wrapped around a layer of light fascia 5. In places of ligation of heavy fascia 3 mounting loops are provided 7. In the ravine at a certain distance from each other along the cross-section line bottom sills 8 are arranged from dense rows of horizontally laid heavy fascines 3. Along the coastal zones of the ravine above the top of the borders of the bottom sills 8, there are sloping fastenings 9 on the left and right banks from the rows of light fascines 5, laid in parallel rows in the direction of the flow of water, and under the gabion net. Sloping mounts 9 along the upper line of the fascin rows are nailed to the surface of the earth with the help of stakes 10.

The method of construction of an erosion control structure of a biopositive structure is carried out and works as follows.

First, the required amount of heavy 3 and light 5 fascines is made. Then, in the ravine along the line of the eroded zone 1, places for bottom rapids 8 are planned, where, in turn, they are laid in tight rows and mounted heavy fascias 3. The number of bottom rapids 8 and the distance between them are selected depending on the geomorphological conditions of the ravine and the hydrological characteristics of the maximum surface water flow . In any case, the number of thresholds 8 should be at least two, and the number of rows of heavy fascines in one threshold should be at least three. Further along the coastal zones the eroded surface of the slopes is cleared and planned above the borders of the top of the fascin thresholds 8. Light fascines 5 are laid in parallel rows in one layer to the level of the top of the sodded surface of the earth 2. A gabion net is wrapped on top of the dense rows of light fascias 5 and attached to the earth's surface along the line the upper row of light fascines 5, and in the lower part - to the gabion net 6 of heavy fascines 3. Thus, flexible slope mounts 9 are made of light fascines 5 on the left and right banks of the ravine. To attach these flexible sloping fasteners to the surface of the earth, wooden or metal stakes 10 are used, which are clogged at a certain distance from each other along the upper fastening line. After the construction is completed, it is advisable to water heavy fascines in order to sprout seeds and plants faster.

The anti-erosion structure of the biopositive structure has a high degree of flexibility and water permeability, and works in this way. The main hydrodynamic loads of the surface runoff of water are perceived by bottom sills 8 from heavy fascines 3 and evenly distributed over the entire cross section of the ravine due to the design flexibility. In this case, a partial quenching of the excess energy of the water runoff occurs, and between thresholds 8, a sharp drop in the longitudinal runoff velocities occurs, thereby preventing possible erosion of the bottom of the ravine. In addition, due to the permeability of heavy fascia 3 and light fascia 5 and the flexibility of their design prevent possible filtering deformation (contact erosion) of the base soil. Siltation occurs between the bottom sills 8 and the overgrowth of the structure and the entire eroded surface of the ravine.

The use of reeds in heavy and light fascines provides not only water permeability and flexibility of the structure, but also helps to preserve moisture in the body of the structure for a long time, which creates good conditions for the germination of grass and shrubs at the bottom of the ravine and on coastal slopes. Over time, the entire fastening of heavy and light fascias will completely overgrow with grass and shrubs, and in a few years the entire structure will turn into a continuous turf, sprouted by the branches of plants up and roots down and in breadth.

Thus, the anti-erosion structure erected by the proposed method will turn into a biopositive engineering structure that does not interfere with the circulation of substances and energy, helps the development of nature and is included in the ecosystem of the territory, perceived by nature as akin to it.

The method of erecting an anti-erosion structure of a biopositive structure can most effectively be used on foothill and mountain areas of natural protected areas, as well as on coastal zones of rivers and reservoirs.

Information sources

1. P.M. Stepanov, I.Kh. Ovcharenko, P.S. Zakharov. Hydrotechnical anti-erosion facilities. - M .: Kolos, 1980, p. 65-68 and p. 73-75.

Claims (1)

A method of erecting an anti-erosion structure, including a multi-stage differential, characterized in that the steps of the structure are arranged in the form of bottom thresholds from the rows of heavy fascines of a biopositive structure, which are laid across the channel and normal to the direction of the surface water flow, while the thresholds from heavy fascias are placed at a certain distance from each other from each other over the entire eroded section of the ravine and made of three or more rows, tightly laid in a horizontal layer of heavy fascines, and along the coastal slopes of räga above the top fascine thresholds parallel rows in a single layer to a level ground surface matted and the direction of water flow lungs fascines laid on top of which adhesive qualities gabion mesh and attach it to the slopes and to the metal grid heavy fascines.

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