RU2222666C2 - Riverside protecting installation - Google Patents

Abstract

FIELD: hydraulic engineering construction, prevention of bank cutting and re-formation of river beds for purposes of their control. SUBSTANCE: riverside protecting installation includes semi-dam of stepped structure made of reinforced concrete with height of steps growing towards bank. Semi-dam is divided by functional-deformation joints into blocks and has T- shaped cross-section with flange oriented downwards. Flange presents flexible foundation bordering on hollowed bottom. Flexible apron of rectangular shape in plan adjoining semi-dam on front includes functional-deformation joint and reinforcing net. Installation presents flexible stepped structure reinforced by net embedded in horizontal plane in body of semi-dam and divided by functional-deformation joints into intercoupled blocks of T-shaped cross-section joined with the aid of reinforcing net. Wall of semi-dam has width diminishing towards top. EFFECT: enhanced operational reliability, reduced labor input to building of riverside installation. 1 cl, 7 dwg

Description

 The invention relates to hydraulic engineering and can be used as a shore protection structure to prevent erosion of river banks and the reformation of river channels with a view to regulating them.

 A device is known for protecting the base of river bank protection structures from washing out [1], which is a continuous flexible design of an anti-erosion device that provides reliable protection of the bank protection structure in rivers, flood floods of which are characterized by high abrasive and conveying abilities. The device consists of gabion mattresses, horizontally laid out towards the riverbed, connected to the protected structure with the help of articulated joints and on top of which are disposed tire covers, interconnected by longitudinal and transverse reinforcing bars that form a connected grid and passing along and across the rows of tires through the middle of the tread parts of the tires by their diameter. When the channel erodes into the formed funnel, the mattress is self-immersed with a load, starting from its end.

The disadvantages of this technical solution are:
- a large mass of the structure and therefore large specific loads on the foundation soil;
- the complexity of the design caused by the presence of a large number of different materials, in particular the use of rubber, which is not always available and widespread in large quantities;
- insufficient design flexibility when using it in the front part of a half-dam, and with significant deformations a gap in the gabion net is possible;
- the proposed technical solution does not provide prevention from erosion of the wall along the entire length, since it is not a solid apron articulated adjacent to the retaining wall.

 The closest technical solution is a shore protection structure [2], which includes a semi-dam of a step structure made of concrete and reinforcement fixed to the coastal slope, with the step height increasing towards the shore and divided by structurally-expansion joints to interconnected blocks.

The disadvantages of this technical solution are:
- a possible washing away of the end of the base of the spur with stream jets flowing around the barrier, which is a spur and, as a result, deepening it down and violating the integrity of the structure;
- a large mass of the structure and therefore large specific loads on the soil of the base, contributing to the washing of the structure and lowering down;
- the relative complexity and inefficiency of the technical solution.

 The purpose of the invention is to increase operational reliability and reduce the complexity of construction.

 This goal is achieved by the fact that the upper slope of the dam is secured by half-dams, which have a T-shaped cross-sectional shape, and a shelf oriented downward. Semi-dams are installed transversely to the moving stream, and the distance between them depends on the length of the half-dams so that a stagnant zone is formed in the inter-dam space for the deposition of suspended particles, which begin to precipitate under the influence of their own weight. The shelf is a flexible foundation, broken by structural and expansion joints into blocks that are interconnected from all four sides with a reinforcing mesh. A flexible foundation allows you to reduce the specific load on the soil of the base from the action of the deadweight of the half-dam and thereby reduce the washout under the structures and the speed of deepening of the half-dam into the ground over time.

 On the front side of the half-dam adjoins a flexible apron, having a rectangular plan in plan and overlapping a possible erosion pit. The flexible apron is divided by structural expansion joints into enlarged aggregated blocks interconnected by a reinforcing mesh. When a flexible apron is deformed, the integrity of the structure is not violated due to the interconnection of each individual block from all four sides with a reinforcing mesh to adjacent blocks. A half-dam enters the horse slope of the dam and is fixed in it. On the front side of the half-dam, the flow rates flowing around it increase and the process of washing away the flexible apron begins, which, under the influence of its own weight, starts to sink down and prevent possible deformations of the half-dam itself. At the same time, the apron, sinking down during erosion, after a while begins to wilt and turns into an anchor. Possible deformation of the semi-dam structure does not violate structural integrity and does not affect its operation due to the presence of structural-expansion joints that make the structure of the structure flexible and changeable. The individual structural blocks are interconnected by a reinforcing mesh, which makes the construction of the semi-dam flexible.

 The block design of the half-dam increases its flexibility and variability. Semi-dams change the kinematic structure of the flow in such a way that stagnation zones are formed at the coastal part of the earth dam and the erosion process stops, and in the immediate vicinity of the contact between the dams and the dam, siltation begins on its lower side. Suspended and entrained particles under the influence of their own weight begin to precipitate due to a decrease in the weighing force caused by a decrease in the flow rate.

 The presence of a shelf, which serves as a flexible foundation, lowers the center of gravity of the cross section and makes the structure more resistant to possible static and deformation changes.

 Figure 1 shows a plan of a dam with shore protection structures; figure 2 is a longitudinal section of a shore protection structure; figure 3 is a section aa in figure 2 for the option when the shelf is formed by the connection of the two postcards; figure 4 is a section bb in figure 2 for the option when the shelf is formed by the connection of the two postcards; in FIG. 5 is a section AA in FIG. 2 for a variant where the shelf has a solid structure with a wall and a decreasing wall width up; in Fig.6 is a section bb in Fig.2 for the option when the shelf has a solid structure with a wall and a decreasing width of the wall up; 7 shows a perspective view of a shore protection structure.

 The shore protection structure consists of a bulk soil dam 1, in the uphill slope 2 of which a half-dam 3, consisting of blocks 4, is wedged. The cross-section of the half-dam 3 has a T-shape, the wall 5 of which is oriented upwards, and the shelf 6 is adjacent to the bottom of the base. Shelf 6 can also be formed as a result of the adjoining of two openings 7 to the wall 5, and between them a structural-expansion joint 8 can be provided. Half-dam 3 is divided by transverse structural-expansion joints 9 into blocks 4 interconnected by reinforcing mesh 10. In the shelf 6, which is a flexible foundation, a reinforcing mesh 11 is provided. A flexible apron 12 is adjacent to the front of the shelf 6.

 The shore protection structure is mounted and operates as follows.

On the upper slope 2 of dam 1, half-dams 3 are fixed, which have a T-shaped cross-sectional shape and a shelf 6 oriented downward. Semi-dams 3 are installed across the moving stream at an angle of 15-20 ^o to the transverse axis, and the distances between them depend on the length of the half-dams 3 so that a stagnant zone is formed in the inter-dam space for sedimentation of particles in suspension and which, under the influence of their own weight, begin to besieged. Shelf 6 is a flexible foundation broken by structural and expansion joints 9 into blocks 4, which are interconnected from all sides by reinforcing mesh 11. A flexible foundation 6 allows to reduce the specific load on the ground from the action of the dead weight of the half-dam 3 and wall 5, thereby preventing washing under the structure and the rate of deepening of the half-dam 3 into the ground over time during operation.

 A flexible apron 12 is adjacent to the front side of the half-dam 3, having a rectangular shape in plan and overlapping a possible erosion pit. The flexible apron 12 is divided by structural expansion joints 9 into interconnected large blocks interconnected by a reinforcing mesh 11. When the flexible apron 12 is deformed, the structural integrity is not violated due to the interconnection of each individual block from all four sides with the reinforcing mesh 11 to the adjoining blocks. Half-dam 3 enters the uphill slope 2 of dam 1 and is fixed in it. On the front side of the half-dam 3, the flow velocities flowing around it increase and the process of washing away the flexible apron 12 begins, which, under the influence of its own weight, starts to lower and prevent possible deformations of the half-dam itself 3. At the same time, the flexible apron 12, lowering down after erosion, after some time begins to stale and turn into an anchor. Possible deformations of the half-dam structure 3 do not violate structural integrity and do not affect its operation due to the presence of structural-expansion joints 9, which make the structure of the structure flexible and changeable. The individual structural blocks are interconnected by a reinforcing mesh 10, which makes the construction of the semi-dam flexible.

 The presence of the shelf 6, which is the foundation, shifts down the center of gravity of the T-section cross-section and increases the stability of the half-dam from possible deformative changes caused by the influence of the water stream.

 The block design of the half-dam increases its flexibility and variability. Semi-dams change the kinematic structure of the flow in such a way that stagnation zones are formed at the coastal part of the earth dam and the erosion process stops, and in the immediate vicinity of the contact between the dams and the dam, siltation begins on its lower side. Suspended and entrained particles under the influence of their own weight begin to precipitate due to a decrease in the weighing force caused by a decrease in the flow rate.

 The presence of a shelf, which serves as a flexible foundation, shifts down the center of gravity of the cross section and makes the structure more stable against possible static and deformation changes.

 The proposed design with a T-shaped cross-section will significantly save the building material used for construction of a semi-dam and will make the design more economical and reliable in operation.

 This shore protection structure can be used on mountain and lowland rivers and as a straightening structure for regulating river channels.

 The shore protection structure will provide reliable protection against erosion of the dam and flooding during flood expenses of settlements falling into this zone.

Sources of information
1. A. p. USSR 1583515, MKI E 02 3/12. A device for protecting the base of river bank protection structures from washing out (S.O. Kurbanov, V.V. Zmeeva, Z. A. Ozrokova and E.A. Torshin); application 04/05/88; publ. 08/07/90, Bull. 29.

 2. Patent of the Russian Federation 2076168, MKI E 02 B 3/12. Coastal protection / publ. 03/27/97.

Claims (2)

1. A coastal protection structure containing a half-dam of a stepped construction made of concrete and reinforcement, with a height of steps increasing towards the shore and divided by structural and expansion joints into blocks, characterized in that the half-dam has a T-shaped cross-section with a shelf oriented downward, which is flexible foundation adjoining it to the eroded bottom, and on the front side of the half-dam adjoins a flexible apron having a rectangular plan in plan, broken structurally-deformation seams on blocks interconnected on all sides by a reinforcing mesh, and the structure is a flexible step structure reinforced by reinforcing grids laid horizontally in the body of a half-dam, and broken by transverse structural-expansion joints on interconnected blocks of a T-shaped cross section, which are interconnected by reinforcing bars the grid. 2. Shore protection structure according to claim 1, characterized in that the half-dam wall is made with a width decreasing upward in its height.

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