RU2270291C1 - Longitudinal through bank-protection structure - Google Patents

Abstract

FIELD: hydraulic and irrigation building, particularly to protect banks of rivers, channels, dam slopes and other structures against erosion.

SUBSTANCE: bank-protection structure consists of shafts fixed in gabions from lower ends thereof. The gabions comprise nets filled with stones and have cylindrical shapes built below eroded zone level. The shafts are vertically installed in the foundations in one or several rows. The shafts are spaced apart and installed in direction parallel to river flow. The shafts are trees or reinforced concrete posts fixed inside the gabion by stones. The cylindrical gabions are connected to net laid along river flow in horizontal plane. Space between vertical shafts and bank may be filler with trees or bushes. Cylindrical gabion tops may be covered with concrete.

EFFECT: increased efficiency of bank protection and extended service life of bank-protection structure.

6 cl, 5 dwg

Description

The invention relates to hydraulic engineering and land reclamation construction and can be used as shore protection structures in eroded riverbeds, canals, slopes of dams, designed for various purposes, and other structures.

A device for attaching a slope of an earth structure [1] is known, comprising a synthetic filter coating laid on the slopes, retaining elements and a layer of stone outline. The holding elements are made in the form of crossbars, racks with hinges, ropes, mesh and limiters. The stone sketch is made in the form of gravel. The lower ends of the uprights are pivotally attached to the crossbar, and their upper ends to the rope. A mesh is attached to the rope. One of the ends of the rope is attached to the crossbar, and their other free ends are stretched due to the application of force and rack, and the crossbar are connected by K-stops. Between the coating and the mesh, a layer of stone is laid. A layer of gravel protects the coating from dynamic wave action. In turn, it is reliably protected by a mesh held in place by ropes. The disadvantage of this technical solution is that:

- the mount is directly in contact with the fluid flow and entrained sediments and therefore can undergo rapid attrition and destruction in a short time;

- the design is a rather complicated technical solution, which makes it unreliable in operation and expensive in cost;

- the efficiency of fastening is significantly reduced when there are large fluctuations in the water level, fluctuations in speed and flow rate in the river or canal;

- this technical solution is ineffective for use in cases where the local building material is trees or shrubs.

The closest technical solution is a longitudinal through shore protection structure [2]. The disadvantages of this technical solution are:

- insufficient work efficiency and sedimentation sedimentation process;

- fastening in economic terms is not always an effective technical solution due to the use of industrial reinforced concrete structures.

The purpose of the invention is to increase the efficiency and reliability of protecting the banks of riverbeds from erosion and durability of the life of the shore protection structure.

The goal is achieved by the fact that on the protected eroded section of the river bank a pit is excavated along the direction of the flow to a depth exceeding the depth of erosion. Cylindrical gabions are being constructed in the pit. Cylindrical gabions consist of grids into which stones are filled. As a mesh, you can use woven mesh of wire with a thickness of 4 ÷ 5 mm or a hexagonal mesh with double torsion. The height of the cylindrical gabions is calculated and depends on the height of the installed columns and the hydrodynamic pressure on them. In cylindrical gabions, in a line from each other at some distance along the direction of flow of the river, vertical reinforced concrete pillars or trees are installed. When installing trees, it is desirable to preserve the root part, which will be covered with stones, to enhance the degree of their fixing in cylindrical gabions. Cylindrical gabions can be interconnected. Thus, an artificial through barrier is formed, which cuts off the main stream from the eroded shore. Part of the flow flows into the formed space between vertical reinforced concrete pillars or trees and greatly reduces the velocity of the longitudinal flow to a value that makes it possible to exclude the loss of suspended sediment. This speed depends on the density of the installation of vertical reinforced concrete pillars or trees and is selected depending on the fractional composition of river sediments. So when the sediment content is predominantly sand fractions, it is necessary to design speeds equal to 0.2-0.3 m / s. If fractions are less than sandy, then the speed should be less.

Vertical reinforced concrete pillars or trees can be installed in two or more lines at some distance along the direction of flow of the river. With this installation, the efficiency of quenching the high-speed flow of the river flowing behind a longitudinal through shore protection structure and the rate of sediment deposition to the bottom are greatly enhanced.

At the bottom, to increase the rigidity of the through shore protection structure, a grid can be laid on which cylindrical gabions will be installed. The mesh will increase the rigidity of the longitudinal through shore protection structure and prevent stones from falling out of cylindrical gabions.

To increase the rigidity of cylindrical gabions, the top can be covered with concrete 7-15 cm thick. Concrete coated gabions have a more rigid structure and are less susceptible to dynamic loads from the action of the water flow.

The space between reinforced concrete trunks or trees and the shore protected from erosion to fill the silting process can be filled with trees or shrubs. As a result of filling this space with trees or shrubs, the flow rates in this space are greatly reduced and the sedimentation process is greatly accelerated. As a result of this filling, the process of overgrowing of this space with shrubs and trees after siltation is greatly accelerated.

Figure 1 shows a plan of a river with a longitudinal through shore protection structure; figure 2 is a section aa in figure 1 with reinforced concrete pillars; figure 3 is a section aa in figure 1 with trees; figure 4 is a plan of the river with a longitudinal through shore protection structure installed in two lines; figure 5 - cylindrical gabions, axonometry.

On river 1 on eroded bank 2, a longitudinal through one-row shore protection structure 3 or two-row is installed 4. For this, at a depth greater than the depth of erosion, cylindrical gabions 5 are deepened, into which concrete columns 6 or trees are vertically installed 7. Cylindrical gabions 7 consist of a grid 8 filled with stones 9. A mesh 10 is laid under the cylindrical gabions 7. To improve the siltation of the space behind the vertical reinforced concrete pillars 6 or trees 7 and the eroded shore 2, it is filled with wood yami 12.

A longitudinal through shore protection structure is constructed and operates as follows. On the protected eroded section 2 of the bank of the river 1, a pit is excavated along the direction of the flow stream to a depth exceeding the erosion depth (Fig. 1). Cylindrical gabions 5 are constructed in the foundation pit. Cylindrical gabions 5 consist of nets 8 into which stones 9 are filled. In cylindrical gabions 5, vertical reinforced concrete pillars 6 or trees 7 are installed in a line from each other at some distance along the direction of the river flow direction (Fig. .2, 3). Thus, an artificial through barrier is formed, which cuts off the main flow from the eroded shore 2. A part of the flow flows into the formed space between the vertical reinforced concrete pillars 6 or trees 7 and greatly reduces the longitudinal flow velocity to a value that makes it possible to exclude the loss of suspended sediment. This speed depends on the density of the installation of vertical reinforced concrete pillars 6 or trees 7 and is selected depending on the fractional composition of the sediments of river 1. So, when the sediment content is mainly sandy fractions, it is necessary to design velocities of 0.2-0.3 m / s. If fractions are less than sandy, then the speed should be less.

Vertical reinforced concrete pillars 6 or trees 7 can be installed in two 4 or more lines at some distance along the direction of flow of the river (figure 4). With this installation, the efficiency of quenching the high-speed flow of the river 1, flowing behind the longitudinal through shore protection structure 4, and the rate of sediment deposition to the bottom are greatly enhanced.

At the bottom, in order to increase the rigidity of the through shore protection structure, a grid 10 can be laid in a horizontal plane on which cylindrical gabions 5 will be installed. The grid 10 will increase the rigidity of the longitudinal through shore protection structures 3 or 4 and prevent stones 9 from falling out of the cylindrical gabions 5.

To enhance the rigidity of cylindrical gabions 5, the top can be covered with concrete 12 (Fig. 5) 7-15 cm thick. Covered with concrete 12, cylindrical gabions 5 have a more rigid structure and are less susceptible to dynamic loads from the action of the water flow.

The space between reinforced concrete trunks 6 or trees 7 and the bank 2 protected from erosion to fill the siltation process can be filled with trees or shrubs 11 (Fig. 1). As a result of filling this space with trees or shrubs 11, the flow rate in this space is greatly reduced and the sedimentation process is greatly accelerated. As a result of this filling, the process of overgrowing of this space with shrubs and trees after siltation is greatly accelerated.

Flexibility is a huge advantage of this structure, since it is in the water and it is impossible to avoid deformations of the bottom and base, and this will entail the deformation of the structure, which is not dangerous for this type of coastal protection.

The proposed technical solution has several advantages over other previously known. In the proposed technical solution, you can use local building material, which is the cheapest and most affordable.

The proposed technical solution is cheaper than similar ones due to the use of local building material, as well as by reducing the required quantity. Moreover, the durability of these structures is greater than previously known similar technical solutions.

In environmental terms, this is the most favorable solution to the problem of protecting coasts from erosion.

Information sources

1.A.c. 1461821 USSR, MKI E 02 D 17/20. A device for fastening the slope of an earth structure / Shkundin B.M. and Novozhilov A.P. (USSR); Statement 04.03.87; publ. 28.02.89, Bull. No. 8 (analogue).

2. Altunina S.T. Regulation of channels, Moscow, "Selkhozgiz", 1956, p.102-103. (prototype).

Claims (6)

1. A longitudinal through shore protection structure, consisting of trunks, fortified from below in gabions, consisting of a net and stones, characterized in that the gabions are made in the form of cylindrical gabions, buried below the erosion depth, in which they are vertically installed in one or more lines at a certain distance trunks from each other along the direction of flow of the river.  2. The construction according to claim 1, characterized in that the vertical trunks are trees, the root part of which is fixed with stones in cylindrical gabions. 3. The construction according to claim 1, characterized in that the vertical trunks are reinforced concrete pillars, one end of which is fixed with stones in cylindrical gabions. 4. The construction according to claim 1, characterized in that the cylindrical gabions are attached to a grid laid along the flow in a horizontal plane. 5. The construction according to claim 1, characterized in that the space between the vertical trunks and the shore is filled with trees and shrubs.     6. The construction according to claim 1, characterized in that the top of the cylindrical gabion is covered with concrete.

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