RU2319805C2 - Method for bio-positive spur dike erection - Google Patents

Abstract

FIELD: hydraulic and environment protective structures, particularly stream regulation and water conservation zone recovery.

SUBSTANCE: method involves mounting timber crib and laying gabion mats made as bags filled with vegetable soil and light-weight fascines, which are laid in alternating layers and placed in mesh shells of prismatic cells of crib structure frame. First of all solid layer of light-weight fascines are placed in each cell. The fascines located in base are horizontal and oriented in spur dike direction. Side fascines are vertical and connected to mesh. Cell interior is fully filled with tightly sealed bags containing vegetable soil and connected with each other. Solid light-weight fascines are laid on bag layer. Gabion mesh is stretched over fascines and connected to side mesh parts. Spaced apart timber piles are driven about head part of spur dike so that the piles are in immediate proximity to crib walls. The piles are connected with each other and with gabion mats by means of reinforcement wires secured to anchor built in bank slope. Bank slope is reinforced with gabion mats including light-weight fascines between spur dikes. Before spur dike mats laying bags of upper and side rows are filled with vegetable soil mixed with seeds of water-resistant plants having extended root systems.

EFFECT: increased usage efficiency, decreased material consumption and possibility to recover green plantations along river and canal banks.

Description

The invention relates to hydraulic engineering and environmental construction and can be used in the regulation of channels and the restoration of coastal water protection zones of rivers.

A known method of erecting a gabion mount [1], including laying along the banks of the channel on the base of a stone-filled gabion prismatic shape. Before laying the gabions on the base, the porous space between the stones is filled with fertile soil with the seeds of hygrophilous plants sown, and then they are kept in an aqueous or moist environment until the root system has fully germinated and reinforced, while the gabion itself is made with an inclined prismatic frame containing a hinge in the center, which connects the stretch marks with the hinges at the tops of the gabion. Gabions are laid in layers with a shift of transverse seams in the section of the channel, and between the layers seams of fertile soil are made. The disadvantages of this technical solution are:

- the complexity of the design and construction method;

- the need for a large amount of stone material;

- the plant soil between the gabions and their stones, as well as in the base, will be eroded during the wave action of the flood stream, additional costs will be required for drainage antifiltration measures.

Semi-dam and a method of its construction are also known [2], including a stepped reinforced concrete tray and a flexible head. The tray consists of L-shaped blocks arranged in a row in pairs against each other. In this case, the highest blocks are installed in the root part, cut into the shore, and relatively low - in front. Inside and sideways, adjacent blocks are rigidly interconnected; stiffeners are installed on top of the tray across the tray. The front tray is closed by a reinforcing grill, inside it is filled with gravel and pebbles. The flexible head of the structure is made of precast concrete blocks pivotally connected to each other and the reinforcing belt of the tray. The main disadvantages of this technical solution are:

- high material consumption of the structure;

- the impossibility of their construction on flat sections of rivers passing in easily eroded muddy soils.

The purpose of the invention is the reduction of material costs for the construction of structures and increase the efficiency and biopositivity of its design.

This goal is achieved by the fact that in the method of erecting a semi-dam of a biopositive design, including the installation of wooden robes and laying of gabion mattresses, the mattresses are made of bags with vegetable soil and light fascia, stacked in layers in the mesh shells of the prismatic cells of the structural framework of the structure. At the same time, a dense layer of light fascin is placed in each cell along the perimeter of the structure, with the base horizontally in the direction of the half-dam, and vertically on the sides with their attachment to the grid. The inner part of each cell is filled to the top with layers of bags of soil tightly bandaged and connected to each other, a continuous layer of light fascin is laid on top of the bags, on top of which a gabion net is stretched with its attachment to the side layers of the net. Around the head part of the half-dam close to the mantle walls and at a distance from each other, wooden piles are hammered together and with gabion mattresses using reinforcing wire, firmly attached to the anchor arranged in the coastal slope behind the structure. Before laying in mattresses, bags of the upper and side rows are filled with fertile soil with sowing seeds of perennial grasses and shrubs with a developed root system.

Figure 1 shows a section along the longitudinal axis of the half-dam; figure 2 is the same in plan; figure 3 shows a cross section of a half-dam; figure 4 - light fascia.

The semi-dam of the biopositive structure consists of wooden trellised ropes 1, forming a prismatic and cellular structure of the structure, inside of which gabion mattresses 2 are made, made of bags 3 with vegetable soil, layered in a flexible shell of light fascia 4, and a gabion net 5 stretched inside the muzzle cells of the half-dam. In one half-dam at least three cells are arranged, respectively, with three or more gabion mattresses 2, firmly connected to each other by means of a metal wire. Around the head of the half-dam, wooden piles 6 are clogged, firmly connected to each other and with gabion mattresses 2 using reinforcing wire 7 attached to anchors 8 located in the coastal slope above the mount. Half dams are located at a certain distance from each other. The coastal slope behind and between the dams is strengthened by gabion mattresses 9, the fillings of which are only light fascines 4.

The method of construction of semi-dams biopositive design is carried out and works as follows.

According to the proposed method, the required number of bags 3 with vegetable soil is pre-harvested, including bags with fertile soil with the addition of seeds of hygrophilous plants with a developed root system. At the same time, bags 3 with fertile soil are watered with water so that the plants overgrow faster. Together with them, light fascines 4 are prepared in advance from the reeds, the length of the fascines is 2-3 m, the diameter is 0.1-0.2 m. After that, a trench is developed under the semi-dam with a slope and direction against the current from the coast towards the river bed. The prefabricated elements of wooden trellised ropes 1 are mounted in the form of a rectangular prismatic frame, inside of which gabion grids 5 are stretched along the designated cells with each other and attached to the elements of the rods 1, so that the upper part of the frame remains open. Further, inside the skeleton of the half-dam, light fascines 4 are laid along the cells in the base and on the sides with the formation of dense single-layer rows. At the same time, the fascines 4 are laid horizontally in the direction of the structure, and vertically on the sides with their attachment to the gabion net 5. The inner part of the frame is filled with cells 3 from plant soil in cells in fascia shells, laid in layers in dense rows to the top, and on the sides of the string cells of the structure and its topmost layer are stacked from bags 3 with more fertile soil with the addition of seeds of hygrophilous plants. On the top of the bags, another row of light fascines 4 is laid so that they tightly overlap the entire upper row of bags 3. On top of the fascin layer, a gabion net 5 is stretched along the entire length of the half-dams with its attachment to the side sections of the net and to the elements of the robes 1. Around the head (head) of half-dams at a certain distance from each other, wooden piles 6 are hammered so that they closely adjoin the masonry walls of the structure. Wooden piles 6 are firmly connected with each other and with gabion mattresses 2 using reinforcing wire 7, which is tensioned to be attached to anchors 8 arranged in the coastal slope. The sections of the coastal slope between the half-dams and behind them are strengthened by gabion mattresses 9, the fillers of which are used only light fascines 4. Material for bags 3 is recommended to use a geotextile (geogrid), which allows water to pass through well and prevents the occurrence of filtration deformations of soils.

During operation, the main load of the flood flow is perceived by half-dams and provide damping and dispersal of it over a large area. Their location with a slope and a direction against the current contributes to the deviation of the surface (coastal) layer of water from the coast towards the river bed. Half-dams work both as spillways and as drainage devices. Wooden piles 6 and ridge 1 provide stability against shear hydrodynamic forces of the flood stream. The design flexibility prevents the concentration of these forces in narrow places, thereby increasing the strength of the structure. In the intervals between the half-dams, there are turbulence zones where sediment sedimentation and siltation take place. When the channel is eroded, erosion pits will form at the ends of the structures under the head parts of the half-dam and they will initially work as consoles. The erosion pits will periodically silt and erode, and over time the gaps between the piles will become clogged with brushwood and fin, after which the erosion pits will completely silt and overgrow with vegetation. In the case of the maximum possible erosion of the channel to the base of the piles, 6 half-dams will work reliably. In the formed deep erosion pits, the head parts of the half-dam will descend and will lie along the slope. When this happens, the tension of the reinforcing (anchor) wire 7, thereby arising the load on the gabion nets 5 are reduced and the strength of the mattresses 4 increases. Although the wooden elements of the towing structures 1 will be partially destroyed at the same time. The main load-bearing elements of structures are gabion nets 5 and reinforcing wires 7, and wooden ryazhenny constructions 1 are for the most part mounting structures than load-bearing ones. And so they collapse after 3-4 years. By this time, half-dams and the gaps between them will be overgrown with grass and shrubs. Every year, as the root system of grasses and shrubs in the body grows half-dammed and the coastal slope grows and develops, the strength and stability of the structures will increase. As a result, these structures will merge with the natural landscape of the coastal zone. At the same time, favorable conditions are created for the reproduction of fish; stagnant and vegetative zones are formed between the half-dams on the riverbed sections. As is known, fish fry feed on insect larvae found in green plants along the water edge.

Thus, the coastal fastener consisting of a semi-dam, erected by the proposed method, will turn into a biopositive engineering structure, which does not impede the circulation of substances and energy, helps the development of nature and is included in the river’s ecosystem, is perceived by nature as akin to it.

The proposed method of erecting a semi-dam of a biopositive design is intended to protect coastal water protection zones of rivers in their flat areas and partially in foothill areas with slopes i≤0.0015. This method most fully meets the modern requirements of environmental legislation and the law on the safety of hydraulic structures, provides at the same time flood protection and restoration of the natural environment.

Information sources

1. Patent for invention No. 2200790. MKI E02B 3/12, E02D 17/20. The method of erection of gabion mounts // Lamerdonov Z.G., Kurbanov S.O., Dyshekov A.Kh. /, 2003

2. Patent for invention No. 2076168, Cl. Е02В 3/00, 3/12 "Half-dam and the method of its construction" / Kurbanov S.O., Tutaev A.A. /, 1997

Claims (3)

1. A method of erecting semi-dams of a biopositive design, including the installation of wooden robes and laying gabion mattresses, characterized in that the mattresses perform a biopositive construction of bags with vegetable soil and light fascia, laid in layers in the mesh shells of the prismatic cells of the structural frame of the structure, while first laying on it the perimeter of the structure in each cell a dense layer of light fascin: to the base - horizontally in the direction of the half-dam, vertically on the sides with their attachment to the grid, and the inside Yu portion of each cell is filled up to the top layer of the bags with vegetable soil, tied tightly above and interconnected bags is placed on top of a continuous row of light fascines, on top of which is stretched gabion mesh with attaching it to the side portions of the grid. 2. The method of erecting a semi-dam of a biopositive construction according to claim 1, characterized in that around the head of the half-dam close to the mantle walls and at a distance from each other, wooden piles are hammered together and with gabion mattresses using reinforcing wire firmly attached to the anchor arranged in the coastal slope, and the coastal slope between the half-dams is strengthened with gabion mattresses, consisting of light fascines. 3. The method of erecting semi-dams of the biopositive structure according to claim 1, characterized in that before laying the mattress frame in the mattresses, the bags of the side and upper rows are filled with fertile soil with the addition of seeds of perennial grasses and shrubs with a developed root system.

Images