Double-layer cofferdam for anti-scouring bridge

Abstract

The utility model discloses a double-layer cofferdam for an anti-scouring bridge, which comprises an inner cofferdam, an outer cofferdam positioned on the outer side of the inner cofferdam and at least one protection unit positioned on the outer side of the outer cofferdam and used for conveying silt on the downstream of the outer cofferdam to the upstream of the outer cofferdam, the outer cofferdam comprises a tip upper outer cofferdam plate facing the water flow direction, two side outer cofferdam plates connected with the tip upper outer cofferdam plate through positioning columns and a lower outer cofferdam plate connected with the two side outer cofferdam plates. According to the utility model, the problem of sediment loss caused by river scouring near the cofferdam is solved.

Description

Technical Field

[0001] This utility model belongs to the field of cofferdam technology, and in particular relates to a double-layer cofferdam for erosion-resistant bridges. Background Technology

[0002] The purpose of a cofferdam is to prevent water and soil from entering the construction site of a structure, facilitating drainage, excavation of foundation pits, and construction of structures within the cofferdam. It is primarily used in hydraulic engineering projects, and is generally dismantled after use unless it is part of a formal building. During the sinking and setting of a cofferdam, the massive cofferdam submerged in the water obstructs the smooth flow of water. Although the upper layer of water can be diverted to the sides after being obstructed by the cofferdam, the lower layer of water may impact the riverbed at the bottom of the cofferdam. Because flow can pass between the bottom of the cofferdam and the riverbed, the water flowing down the sides after impacting the cofferdam will cause scouring of the riverbed at the bottom. Significant scouring of the riverbed will create a large difference in elevation, resulting in a significant elevation difference after the cofferdam is set in place, leading to cofferdam misalignment, creating significant construction hazards, and affecting subsequent construction work.

[0003] Therefore, it is urgent to solve the above problems. Utility Model Content

[0004] Purpose of the utility model: The purpose of this utility model is to provide a double-layer cofferdam for erosion-resistant bridges, which solves the problem of sediment loss caused by river erosion near the cofferdam.

[0005] Technical solution: To achieve the above objectives, this utility model discloses a double-layer cofferdam for scour prevention bridges, including an inner cofferdam, an outer cofferdam located outside the inner cofferdam, and at least one protective unit located outside the outer cofferdam and used to transport silt downstream of the outer cofferdam to the upper part of the outer cofferdam. The outer cofferdam includes a pointed upper outer cofferdam plate facing the direction of water flow, two side outer cofferdam plates connected to the pointed upper outer cofferdam plate by positioning piles, and a lower outer cofferdam plate connected to the two side outer cofferdam plates.

[0006] Optionally, the protection unit includes a conveying bend with the sand inlet located downstream of the outer weir and the sand outlet located upstream of the outer weir, a support leg for supporting the conveying bend, a semi-circular end cap located at the end of the conveying bend, a conveying shaft with helical blades connected to the semi-circular end cap and passing through the conveying bend, and a self-driving component facing the water-facing surface of the outer weir plate at the tip and used to output power to drive the conveying shaft to rotate.

[0007] Optionally, the self-driving assembly includes a protective ring connected to the conveying bend via a bracket, a first propeller mounted within the protective ring via a first bearing bracket, a second propeller mounted within the conveying bend via a second bearing bracket and coaxially mounted with the conveying shaft, and a conveyor belt wound around the first and second propellers. The first propeller is rotated by the impact of the water flow, which drives the second propeller to rotate and drives the conveying shaft to rotate, conveying the sediment from the quicksand inlet to the quicksand outlet.

[0008] Optionally, two protective units are symmetrically arranged on the outer side of the outer perimeter weir.

[0009] Optionally, the outer perimeter weir plate is an L-shaped weir plate.

[0010] Optionally, the positioning pile has an opening for inserting the end of the L-shaped weir plate.

[0011] Optionally, the upper outer perimeter weir plate of the tip includes two inclined weir plates at a certain angle and a vertical weir plate connected to the inclined weir plates.

[0012] Optionally, the positioning pile has an opening for inserting the end of the vertical weir plate.

[0013] Optionally, the lower outer perimeter weir plate is a horizontal weir plate.

[0014] Optionally, the positioning pile is a pile body with a hollow cavity, the hollow cavity being filled with sealing filler.

[0015] Beneficial effects: Compared with the prior art, this utility model has the following advantages: The outer perimeter weir plate at the tip of this utility model helps to divert the scouring force of the river water, has high scouring resistance, and has excellent performance; This utility model adopts the principle of controlling flow with flow, which draws the silt impacted below the outer perimeter weir into the conveying bend pipe through the suction force and the impact inertia of the silt at the sand inlet, and then transports the silt downstream of the outer perimeter weir back to the upstream of the outer perimeter weir through the conveying shaft with spiral blades in the conveying bend pipe, achieving the effect of replenishment and balance. This solves the problem of varying degrees of local scouring during the construction period of the cofferdam, especially during the sinking process, and solves the problem of silt loss caused by river scouring near the cofferdam, thereby ensuring that the cofferdam can land stably and safely and that subsequent construction is safe. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the protective unit in this utility model;

[0018] Figure 3 This is a schematic diagram of the self-driving unit in this utility model. Detailed Implementation

[0019] The technical solution of this utility model will be further described below with reference to the accompanying drawings.

[0020] like Figure 1 As shown, a double-layer cofferdam for scour prevention bridges includes an inner cofferdam 1, an outer cofferdam, and at least one protective unit. The outer cofferdam is located outside the inner cofferdam, and the protective unit is located outside the outer cofferdam. The protective unit is used to transport silt downstream of the outer cofferdam to the upper reaches of the outer cofferdam. In this invention, scour occurs on the upstream side of the outer cofferdam, and siltation occurs on the downstream back side of the outer cofferdam.

[0021] The outer weir includes an upper outer weir plate 2 at the tip, positioning piles 3, a side outer weir plate 4, and a lower outer weir plate 5. The upper outer weir plate 2 at the tip faces the direction of water flow and includes two inclined weir plates 201 and two vertical weir plates 202 connected to each of the two inclined weir plates 201. The two inclined weir plates 201 form a certain angle, which can be obtuse, right, or acute. The inclined surfaces of the two inclined weir plates 201 are the water-facing surfaces of the outer weir. The positioning piles 3 have openings for inserting the ends of the vertical weir plates 202. The ends of the vertical weir plates 202 of the upper outer weir plate 2 are inserted into the openings of the positioning piles 3, and the upper outer weir plate 2 at the tip is fixedly connected to the positioning piles 3. The side outer weir plate 4 is an L-shaped weir plate. The positioning piles 3 have openings for inserting the ends of the L-shaped weir plates. The ends of the L-shaped weir plates are inserted into the openings of the positioning piles 3, and the side outer weir plate 4 is fixedly connected to the positioning piles 3. The lower outer weir plate 5 is a horizontal weir plate. The lower outer perimeter weir plate 5 is fixedly connected to both ends of the L-shaped weir plate. The positioning pile 3 is a pile body with a hollow cavity 21, which is filled with sealing filler 22. The upper outer perimeter weir plate 2, the positioning pile 3, the side outer perimeter weir plate 4, and the lower outer perimeter weir plate 5 form a ring, forming an outer perimeter weir. After the side outer perimeter weir plate and the upper outer perimeter weir plate are inserted into the opening of the positioning pile, the inside of the positioning pile is filled with sealing filler to achieve sealing and fixation of the outer perimeter weir; finally, the water inside the outer perimeter weir is pumped out by a pumping device. The outer perimeter weir with a pointed upper outer perimeter weir plate helps to divert the scouring force of the river water, resulting in excellent performance.

[0022] like Figure 2 As shown, two protective units are symmetrically arranged on the outer side of the outer weir. Each protective unit includes a conveying bend 8, support legs 9, a semi-circular end cap 10, a spiral blade 11, a conveying shaft 12, and a self-driving assembly 13. The quicksand inlet 6 of the conveying bend 8 is located downstream of the outer weir, and the quicksand outlet 7 is located upstream of the outer weir. The support legs 9 are used to support the conveying bend 8. The semi-circular end cap 10 is located at the end of the conveying bend. Both ends of the conveying shaft 12 are connected to the semi-circular end cap via bearings. The conveying shaft 12 passes through the conveying bend and has spiral blades 11 on it. The self-driving assembly 13 faces the water-facing surface of the outer weir plate 2 at the tip, and is used to output power to drive the conveying shaft 12 to rotate.

[0023] like Figure 3 As shown, the self-driving assembly 13 includes a bracket 14, a protective ring 15, a first bearing bracket 16, a first propeller 17, a first propeller 18, a second propeller 19, and a conveyor belt 20. The protective ring 15 is connected to the conveying bend 8 through the bracket 14. The first propeller 17 is set inside the protective ring 15 through the first bearing bracket 16. The second propeller 19 is set inside the conveying bend 8 through the second bearing bracket 18. The second propeller 19 is coaxially arranged with the conveying shaft 12. The conveyor belt 20 is wound around the first propeller 17 and the second propeller 19. The first propeller 17 is rotated by the impact of the water flow, which drives the second propeller 19 to rotate and drives the conveying shaft 12 to rotate, transporting the silt from the quicksand inlet to the quicksand outlet. The quicksand impacted by the water enters the conveying bend from the quicksand inlet and flows out through the quicksand outlet, returning to the silt scour area of ​​the outer weir. This invention solves the problem of sediment loss caused by river erosion near the cofferdam by transporting the sediment below the outer dam back to its original location, thereby ensuring that the cofferdam can be stably and safely placed and that subsequent construction is safe.

[0024] To avoid the potential hazards caused by water flow scouring the riverbed of the cofferdam, the double-layer cofferdam for scour-proof bridges provided by this utility model mainly utilizes the concept of controlling flow with flow. It intercepts the sediment impacted by the outer cofferdam and returns it to its original position. The conveying bend is a common stainless steel conduit made into an arc-shaped bend. The conveying bend is fixed to the riverbed by support legs. A quicksand inlet is opened at one end of the conveying bend, and a quicksand outlet is opened at the other end. In order to ensure the interception effect of sediment, the quicksand inlet is opened towards the outer cofferdam plate on the back side. In order to facilitate the discharge of sediment, the quicksand outlet is set near the outer cofferdam plate at the upper part of the tip on the front side. The quicksand enters the conveying bend from the quicksand inlet and flows out through the quicksand outlet, returning to its original position, thus achieving the immediate replenishment and balance of sediment below the outer cofferdam.

[0025] The silt and other materials impacted by the water flow downstream of the outer weir will enter the quicksand inlet under the influence of the water flow. They will be transported to the quicksand outlet through the spiral blades in the conveying bend and discharged back to the vicinity of the upper outer weir plate on the water-facing side, achieving a replenishment balance. During the sinking and settling process of the outer weir, the lower layer of water flow may impact the riverbed at the bottom of the outer weir. The double-layer cofferdam for anti-scour bridges of this utility model can achieve a replenishment balance, effectively solving the problem of varying degrees of local scour that occurs during the construction period of the cofferdam, especially during the sinking process.

Claims

1. A double wall cofferdam for scour protection of a bridge, characterized in that The invention relates to a sand control device, which comprises an inner weir (1), an outer weir located outside the inner weir, and at least one protection unit located outside the outer weir and used for transporting the sand downstream of the outer weir to the upstream of the outer weir.

2. The double wall cofferdam for a scour protected bridge according to claim 1, wherein The protection unit comprises a transporting elbow (8) with a quicksand inlet (6) located downstream of the outer weir and a quicksand outlet (7) located upstream of the outer weir, a supporting leg (9) used for erecting the transporting elbow, a semicircular end cover (10) located at the end of the transporting elbow, a transporting shaft (12) with helical blades (11) connected with the semicircular end cover and arranged in the transporting elbow, and a self-driven assembly (13) located towards the water surface of the tip upper weir plate (2) and used for outputting power to drive the rotating of the transporting shaft (12).

3. The double wall cofferdam for a scour protected bridge according to claim 2, characterized by, The self-driven assembly (13) comprises a protection ring (15) connected with the transporting elbow through a support (14), a first propeller (17) arranged in the protection ring through a first bearing bracket (16), a second propeller (19) arranged in the transporting elbow and coaxially arranged with the transporting shaft through a second bearing bracket (18), and a conveyor belt (20) arranged around the first propeller (17) and the second propeller (19), the first propeller (17) is rotated by the water flow, drives the rotating of the second propeller (19), and drives the rotating of the transporting shaft (12) to transport the sand from the quicksand inlet to the quicksand outlet.

4. The double wall cofferdam for a scour protected bridge according to claim 1, wherein Two protection units are symmetrically arranged outside the outer weir.

5. The double wall cofferdam for a scour protected bridge according to claim 1, wherein The side outer weir plate (4) is an L-shaped weir plate.

6. The double wall cofferdam for a scour protected bridge according to claim 5, wherein An opening is arranged on the positioning pile (3) and can be inserted by the end of the L-shaped weir plate.

7. The double wall cofferdam for a scour protected bridge according to claim 1, wherein The tip upper weir plate (2) comprises two inclined weir plates (201) at a certain angle and a vertical weir plate (202) connected with the inclined weir plate.

8. The double wall cofferdam for a scour protected bridge according to claim 7, characterized by, An opening is arranged on the positioning pile (3) and can be inserted by the end of the vertical weir plate (202).

9. The double wall cofferdam for a scour protected bridge according to claim 1, wherein The lower outer weir plate (5) is a horizontal weir plate.

10. The double wall cofferdam for a scour protected bridge according to claim 1, wherein The positioning pile (3) is a pile body with a hollow chamber (21), and the hollow chamber (21) is filled with a sealing filler (22).

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