Grid type scour prevention structure suitable for earth rock cofferdam

Abstract

The utility model belongs to the technical field of cofferdam protection, and particularly relates to a grid type anti-scour structure suitable for an earth rock cofferdam, which comprises a concrete tetrahedron and an anti-scour layer, the anti-scour layer consists of a bottom alloy mesh surface, an anti-scour material and a top alloy mesh surface in sequence from bottom to top, the concrete tetrahedron is arranged at the bottom of the cofferdam, the anti-scour layer is arranged on the slope surface of the cofferdam, and the anti-scour material is arranged on the slope surface of the cofferdam. The concrete tetrahedron at the bottom is used as a foundation, the bottom supporting and point location fixing effects are achieved, and the concrete tetrahedron at the bottom is used as a foundation, so that the concrete tetrahedron can be used for supporting the bottom and fixing point locations. The reserved lower thin steel cables and the reserved upper thin steel cables are used for laying and adjusting the bottom layer alloy net face and the top layer alloy net face, the bottom layer alloy net face and the top layer alloy net face wrap the anti-impact materials and cover the surface layer of the cofferdam, a flexible anti-impact structure is formed, and the integrity and the anti-scouring performance of the surface layer of the cofferdam are effectively improved.

Description

Technical Field

[0001] This utility model belongs to the field of cofferdam protection technology, and in particular relates to a grid-type anti-scour structure suitable for earth-rock cofferdams. Background Technology

[0002] Large-scale hydropower projects in China are located on major rivers with enormous flow rates. Construction diversion measures typically employ tall cofferdams to impound water. In phased diversion schemes, cofferdams often extend along the river. The upstream slope is significantly affected by river erosion, leading to instability of the upstream slope of the cofferdam. Common structural methods include filling with large stones, using concrete tetrahedrons, stacking reinforced gabions, stacking alloy mesh bags, or pouring concrete panels.

[0003] Conventional treatment methods have drawbacks such as incomplete underwater filling, large gaps in the filling, large lifting weight for stacking steel cages, and long extension of the crane boom required for lifting. In actual construction, it is difficult to accurately control the construction quality of the anti-scour structure, which leads to the gradual damage of the cofferdam from the water-facing side. In addition, mountain rivers are prone to sudden rises in water level, and the fluctuation of water level is difficult to predict accurately. Conventional protection methods require construction at a position close to the water surface, which increases the construction safety risks.

[0004] This invention designs a grid-type scour prevention structure suitable for earth-rock cofferdams to solve the above problems. Utility Model Content

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A grid-type scour protection structure suitable for earth-rock cofferdams includes a concrete tetrahedron and a scour protection layer. The scour protection layer consists of a bottom alloy mesh, scour protection material, and a top alloy mesh from bottom to top. The concrete tetrahedron is placed at the bottom of the cofferdam, and the scour protection layer is placed on the slope of the cofferdam. One end of the scour protection layer is located at the bottom of the cofferdam and in contact with the concrete tetrahedron. A lower thin steel cable is threaded through the three lower corners of the concrete tetrahedron, and an upper thin steel cable is threaded through the upper corner of the concrete tetrahedron. The lower thin steel cable passes through the bottom alloy mesh and extends to the top of the cofferdam, and the upper thin steel cable passes through the top alloy mesh and extends to the top of the cofferdam.

[0007] As a preferred embodiment, lower steel reinforcement rings are installed at the three lower corners of the concrete tetrahedron, through which thin steel cables pass. Upper steel reinforcement rings are installed at the upper corners of the concrete tetrahedron, through which thin steel cables pass.

[0008] As a preferred option, the length of the upper reinforcing ring is greater than the length of the lower reinforcing ring.

[0009] As a preferred option, the erosion protection material is stone chips.

[0010] As a preferred option, the particle size of the anti-impact material is larger than the aperture of the bottom alloy mesh and the top alloy mesh.

[0011] Compared with existing technologies, the advantages of this utility model are:

[0012] 1. This utility model uses a concrete tetrahedron at the bottom as a foundation, which serves as a bottom support and fixing point. The reserved lower and upper thin steel cables are used to lay and adjust the bottom and top alloy mesh surfaces. The bottom and top alloy mesh surfaces wrap the anti-erosion material and cover the surface of the cofferdam to form a flexible anti-erosion structure, which effectively increases the integrity and erosion resistance of the cofferdam surface.

[0013] 2. This utility model can reduce the use of large concrete tetrahedrons or large stones, increase the integrity of the water-facing slope structure, and the two bottom alloy mesh surfaces and the top alloy mesh surface further increase the erosion resistance of the cofferdam slope and improve the construction quality. At the same time, this structure does not require underwater construction, and workers and machinery can be far from the water surface, unaffected by water level fluctuations, thus ensuring construction safety. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the present invention.

[0015] Figure 2 This is a schematic diagram of the concrete tetrahedron of this utility model.

[0016] The labels in the diagram are as follows: 1. Concrete tetrahedron; 2. Shock-resistant layer; 3. Bottom alloy mesh; 4. Shock-resistant material; 5. Top alloy mesh; 6. Lower thin steel cable; 7. Upper thin steel cable; 8. Lower reinforcing ring; 9. Upper reinforcing ring. Detailed Implementation

[0017] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following embodiments or drawings are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0018] A grid-type scour control structure suitable for earth-rock cofferdams, such as Figure 1 and Figure 2 As shown, it includes a concrete tetrahedron 1 and an anti-scour layer 2. The anti-scour layer 2 is composed of a bottom alloy mesh 3, an anti-scour material 4, and a top alloy mesh 5 from bottom to top. The concrete tetrahedron 1 is set at the bottom of the dam, and the anti-scour layer 2 is set on the slope of the cofferdam. One end of the anti-scour layer 2 is located at the bottom of the dam and is in contact with the concrete tetrahedron 1. The lower three corners of the concrete tetrahedron 1 are threaded with lower thin steel cables 6, and the upper corners of the concrete tetrahedron 1 are threaded with upper thin steel cables 7. The lower thin steel cables 6 pass through the bottom alloy mesh 3 and extend to the top of the dam, and the upper thin steel cables 7 pass through the top alloy mesh 5 and extend to the top of the dam.

[0019] The bottom concrete tetrahedron 1 serves as the foundation, providing bottom support and fixing points. The reserved lower thin steel cable 6 and upper thin steel cable 7 are used to lay and adjust the bottom alloy mesh 3 and the top alloy mesh 5. The bottom alloy mesh 3 and the top alloy mesh 5 wrap the anti-erosion material 4, covering the surface of the cofferdam to form a flexible anti-erosion structure, effectively increasing the integrity and erosion resistance of the cofferdam surface.

[0020] This structure reduces the use of large concrete tetrahedrons or large boulders, increases the overall integrity of the upstream slope structure, and further enhances the erosion resistance of the cofferdam slope by the two bottom alloy mesh panels 3 and the top alloy mesh panel 5, thus improving construction quality. Simultaneously, this structure eliminates the need for underwater construction, allowing workers and machinery to operate at a greater distance from the water surface, unaffected by water level fluctuations, ensuring construction safety.

[0021] like Figure 2 As shown, lower steel rings 8 are installed at the three lower corners of the concrete tetrahedron 1, and lower thin steel cables 6 pass through the lower steel rings 8. Upper steel rings 9 are installed at the upper corners of the concrete tetrahedron 1, and upper thin steel cables 7 pass through the upper steel rings 9. The length of the upper steel rings 9 is greater than the length of the lower steel rings 8.

[0022] The anti-impact material 4 is stone slag, and the particle size of the anti-impact material 4 is larger than the aperture of the bottom alloy mesh 3 and the top alloy mesh 5.

[0023] Installation steps for a grid-type erosion control structure:

[0024] 1. First, throw the concrete tetrahedron 1 to the toe of the cofferdam slope. The lower thin steel cable 6 and the upper thin steel cable 7 are reserved at the top elevation of the dam. The upper thin steel cable 7 is used to adjust the orientation and placement of the concrete tetrahedron 1. Confirm that both the lower thin steel cable 6 and the upper thin steel cable 7 are in a movable state.

[0025] 2. Connect the head of the bottom alloy mesh 3 to one end of one of the lower thin steel cables 6. Use a winch or pull manually to make the lower thin steel cable 6 slide in the connected lower steel ring 8. The lower thin steel cable 6 drags the bottom alloy mesh 3 towards the bottom of the dam so that the bottom alloy mesh 3 is laid on the slope of the cofferdam. The remaining lower thin steel cable 6 passes through the bottom alloy mesh 3.

[0026] 3. The anti-erosion material 4 is filled from bottom to top on the shore by equipment such as long-arm backhoe excavators, and the slope surface is appropriately trimmed;

[0027] 4. Connect the head of the top alloy mesh 5 to one end of the upper thin steel cable 7. The other end of the upper thin steel cable 7 is also pulled by a winch or manually. The upper thin steel cable 7 slides in the upper steel ring 9 and drags the top alloy mesh 5 towards the bottom of the weir so that the top alloy mesh 5 is laid on the surface of the anti-erosion material 4.

[0028] 5. Tighten the lower thin steel cable 6 and the upper thin steel cable 7, and fix the lower thin steel cable 6 and the upper thin steel cable 7 to the top of the cofferdam.

[0029] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A grid-type scour protection structure suitable for earth-rock cofferdams, characterized by: It comprises a concrete tetrahedron (1) and a scouring prevention layer (2), the scouring prevention layer (2) is sequentially composed of a bottom alloy mesh surface (3), a scouring prevention material (4), and a top alloy mesh surface (5) from bottom to top, the concrete tetrahedron (1) is arranged on a weir bottom, the scouring prevention layer (2) is arranged on a cofferdam slope surface, one end of the scouring prevention layer (2) is located on the weir bottom and contacts the concrete tetrahedron (1), lower thin steel cables (6) are arranged at three end corners below the concrete tetrahedron (1), upper thin steel cables (7) are arranged at an upper end corner of the concrete tetrahedron (1), one end of the lower thin steel cables (6) penetrates through the bottom alloy mesh surface (3) and is fixed on a weir top, and one end of the upper thin steel cables (7) penetrates through the top alloy mesh surface (5) and is fixed on the weir top.

2. The grid-type scour protection structure according to claim 1, characterized in that: Lower steel reinforcement rings (8) are arranged at the three end corners below the concrete tetrahedron (1), the lower thin steel cables (6) penetrate through the lower steel reinforcement rings (8), and upper steel reinforcement rings (9) are arranged at the upper end corner of the concrete tetrahedron (1), the upper thin steel cables (7) penetrate through the upper steel reinforcement rings (9).

3. The grid-type scour protection structure according to claim 2, characterized in that: The length of the upper steel reinforcement rings (9) is greater than the length of the lower steel reinforcement rings (8).

4. The grid-type scour protection structure for earth-rock cofferdams according to claim 1, characterized in that: The scouring prevention material (4) is stone residue.

5. The grid-type scour protection structure according to claim 4, characterized in that: The particle size of the scouring prevention material (4) is greater than the pore size of the bottom alloy mesh surface (3) and the top alloy mesh surface (5).

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