RU2507340C1 - Method and device to prevent erosion of shore edge - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method consists in using a device to prevent erosion of a shore edge. The device comprises elements installed to form braces and arranged with a long side across the flow motion. Elements are netted webs made of flexible material having positive buoyancy. Netted webs are equipped with a float in the upper part and a weight in the lower part and are deepened into the shore edge with attachment to the bottom by means of pins, the length of which is selected to prevent tear-off of the lower edger of the netted web from the bottom with sharp increase of flow speed, variation of its direction or sharp increase of surface level. Netted webs are installed in rows. Side netted webs entering the row stretch from the central one to the opposite side. Rows of netted webs are arranged as different by height for availability of an upper edge on the surface of water and tracking of the profile of the lower edge bottom. The distance between rows is selected so that the distance between adjacent webs shall not be less than two heights of the netted web in this point. Due to flexibility of the netted web, loads are reduced at the structure and places of fixation.

EFFECT: prevented erosion of a shore edge and provides for the possibility of formation of a new shore line.

2 cl, 2 dwg

Description

Technical field

The invention relates to hydraulic shore protection structures.

State of the art

The following shore protection structures are known.

1. A transverse through-shore protection structure (description of the invention to patent No. 227092 of 02.20.2006), consisting of transverse spurs made of trunks, reinforced from below in gabions, consisting of mesh and stones, and gabions made in the form of gabion cylindrical foundations, recessed below erosion depths in which trunks are vertically installed in one or more lines at a certain distance from each other across the directions of the river flow. Trunks are trees or reinforced concrete poles fixed in cylindrical gabions. In this case, cylindrical gabions deepen with distance from the coast [1]. According to the principle of action: a decrease in the speed of the stream flowing through the rows of trunks or reinforced concrete pillars to values causing precipitation of fractional particles of the stream is an analogue of the proposed device “through shore protection structure” [1].

The main disadvantages of this structure are:

- a complex technical solution that causes unreliability in work;

- the fastening efficiency decreases with large fluctuations in the water level, flow rate.

2. Flexible combined cellular fastening (description of the invention to patent No. 2212496 from 09/20/2003), containing mesh and stones. The fastening consists of articulated reinforced concrete elements made in the form of slanting rods having reinforcement outlets with ring tips, the ring tips being fixed with axes on a solid carpet made of netting located along the long side across the flow, with the formation of unchanged interconnected triangular in terms of the shape of the cells, the inner space of which is filled with stone paving, and the mounts abut against the pile tooth, which adjoins the front A flexible apron forming the pile with the tooth shear stable T-shaped section [2].

The closest of the analogues to the proposed invention is patent No. 2212496 from 09/20/2003, which is selected as a prototype.

The disadvantages of this technical solution are:

- the presence of articulated reinforced concrete elements;

- the difficulty of attaching a mesh netting to reinforced concrete elements;

- stone paving inside the trihedral cells gives additional rigidity to the structure, which can be violated with frequent sharp fluctuations in speeds and flow levels.

The invention and its distinctive (from the prototype) features

The technical result is to prevent erosion of the coastal edge of reservoirs, increasing the durability of the life of shore protection structures, reducing the time and cost of their construction.

Common features of the claimed invention with the prototype is a device consisting of elements installed with the formation of braces and located on the long side transverse to the flow. To achieve the technical result of the present invention, protrusions perpendicular to the coastline are used, which reduce the flow velocity at the coastal edge to values causing precipitation of particles suspended in the flow, initially in the protrusion itself, and subsequently as it approaches it. The protrusions contain parallel vertical rows of net webs, the side net webs included in the row diverge from the central in the opposite direction. The rows of net webs are varied in height so that the top edge is on the surface of the water, and the bottom allows you to track the bottom profile.

All rows of net webs are attached to the bottom, the height and distance between which is set depending on the depth of the water flow, and the root part of the net cloth of the coastal edge is buried in the ground.

Mesh webs are made of flexible materials with positive buoyancy, equipped with additional melt in the upper part of the mesh and weight in the lower part, are attached to the bottom with studs, the deepening of which eliminates the separation of the lower edge of the mesh from the bottom with a sharp increase in the speed of the water flow, changing its direction or a sharp change in water level.

The protrusions are placed at a distance of at least two heights of the net web at a given point. With this arrangement of the net web with a minimum number of them, the phenomenon causing erosion of the coastal edge is eliminated or reduced.

Figure 1 shows the direction of flow and excitement of a water stream causing erosion of the coastal edge without a shore protection structure.

Figure 2 shows the changes in the directions and strength of the impact of the water flow on the coastal edge when applying a shore protection structure from net webs.

In figure 1 and figure 2 indicated: 1 - the old coastline; 2 - a new coastline that appears when applying a shore protection structure; 3 - protrusions from the rows of net fabric; 4 - direction and velocity of the water flow in arbitrary units; 5 - the direction of excitement of the water stream.

The invention is carried out as follows.

Along the coastal edge 1 protected from erosion, perpendicular to it, protrusions are created from the rows of the net web 3, which slow down the speed of the water stream 4, which carries out particles of the eroded coastal edge, to the value at which precipitated fractions fall out of the stream, while if in the stream that causes erosion, other fractions are found, then they also precipitate, increasing the amount of precipitated deposits, thereby preventing erosion of the coastal edge, and also forming a new coastline 2.

The protrusions from the rows of net fabric are constructed as follows.

A net web roll folded in such a way that its root end is on the outer side of the roll is started to be unwound, buried in the ground. Having reached the water's edge, the roll is loaded onto some swimming means (pontoon) and they start towing it to the depth, while unwinding the roll of net, attaching the melt and cargo to it. Based on the condition of the coastal strip, the lower selection of the net web can be buried in the soil or fastened to it with studs, the length of which is chosen so as to exclude the separation of the bottom edge of the net web from the bottom with a sharp increase in the flow velocity, change of its direction or a sharp change in the surface level.

In a similar manner, the next row of net is mounted based on the condition that it must be at a distance of at least two heights of net at this point. Lateral net webs included in a row diverge from the central in the opposite direction.

The use of mesh web is the main advantage, since its flexibility in the horizontal, vertical and longitudinal direction significantly reduces the load on it and the mounting location even with sharp changes in dynamic loads.

The proposed technical solution for the use of net web as the main regulator of changes in factors affecting the destruction of the coastal strip allows this to be carried out in a very wide range, changing the characteristics of the net web (pitch, thread diameter) and its spatial position relative to the operating factors.

This technical solution is cheaper than similar ones, since the load is reduced and the use of expensive materials, such as reinforced concrete, is not required.

The proposed technical solution is environmentally friendly, as mesh cloths are made from modern polymeric materials.

Information sources

1. Description of the invention to patent No. 227092 of February 20, 2006, “Transverse through shore protection structure”.

2. Description of the invention to patent No. 2212496 of 09/20/2009 "Flexible combined cellular fastening" - (prototype).

Claims (2)

1. A device for preventing erosion of the coastal edge, consisting of elements installed with the formation of braces and arranged with a long side transverse to the flow, characterized in that the elements are net webs made of flexible material having positive buoyancy and are provided with melt in the upper part and cargo in the lower part, are buried in the coastal edge with fastening to the bottom with studs, the length of which is chosen in such a way as to exclude separation of the lower edge of the net web from the bottom when cutting m increasing the flow velocity, changing its direction or a sharp increase in the surface level, moreover, the net webs are installed in rows, while the side net webs included in the row diverge from the central one in the opposite direction, the rows of net webs are made different in height to find the upper edge on the surface water and tracking the profile of the bottom of the lower edge, while the distances between the rows are selected so that the distance between adjacent webs should be at least two heights of the net fabric in this kyo. 2. A method for preventing erosion of the coastal edge, consisting in using the device according to claim 1.

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