Anti-scouring system for pile foundation

Abstract

The utility model discloses a pile foundation anti-scouring system which comprises a plurality of ring beams with a pile foundation as the center, the height of each beam ring is gradually increased from the periphery to the center to form a concave-convex sequentially-spaced local topography and landform, and the pile foundation anti-scouring system has the effects of dissipating energy and disturbing flow so as to weaken the flow field intensity and reduce the sand carrying capacity of water flow and achieves the anti-scouring purpose. Meanwhile, the fishing effect and the artificial fishing reef function are considered; in addition, the concave negative topography between the ring beams is beneficial to silt falling and deposition of suspended silt in a water body and beneficial to a seabed around the protection pile, and the bottom sealing geotechnical cloth is arranged at the bottoms of the ring beams, so that scour protection is further enhanced.

Description

Technical Field

[0001] This utility model patent relates to the field of marine pile foundation engineering, and in particular to a pile foundation anti-scour system. Background Technology

[0002] The seabed sediments in my country's coastal waters are mostly loose, fine-grained silt and sand, which are easily eroded and washed away by natural hydrodynamic forces such as waves and tides due to their weak interparticle cohesion. In this context, pile foundations are widely used in marine engineering due to their advantages such as high bearing capacity, strong adaptability, good stability, and convenient construction.

[0003] However, after the pile foundation is constructed, the movement of water particles caused by tidal currents and waves will be significantly affected. First, water particles collide with the pile foundation and move towards the seabed, forming a downwelling current and creating a horseshoe vortex in front of the pile foundation. Second, eddies (Kármán vortex streets) will form at the back of the pile foundation. Third, the streamlines on both sides of the pile foundation will contract. This change in local flow pattern increases the shear stress of the water flow on the seabed, thereby increasing the sediment-carrying capacity of the water flow. If the seabed is susceptible to erosion, scour pits will form locally around the pile foundation. Scour pits will affect the stability of the pile foundation, reduce its bearing capacity, and threaten the safe lifespan of marine engineering structures.

[0004] Scour prevention measures for offshore pile foundations include active and passive protection. Active protection weakens the flow field by altering its intensity, reducing its sediment-carrying capacity. Passive protection involves laying protective equipment on the seabed around the pile foundation to enhance its resistance to scour. Currently, most offshore pile foundation projects employ passive protection, primarily using methods such as riprap placement, sandbags, stabilized soil, and interlocking drainage systems. Additionally, there are methods that promote sedimentation, such as using biomimetic grass. However, in practical engineering applications, even with these passive protection methods, inadequate protection and secondary scour often occur due to improper construction management and difficulties in underwater monitoring, leading to localized scour around the pile foundation. Summary of the Invention

[0005] The purpose of this application is to address the aforementioned problems by designing and providing a pile foundation scour prevention system. The technical solution is as follows:

[0006] A pile foundation scour prevention system includes several ring beams centered on the pile foundation. The height of each ring beam gradually increases from the outer perimeter to the center, and a geotextile is installed at the bottom of the ring beam.

[0007] Furthermore, each ring beam can be either a separate unit or a single unit; if it is a separate unit, each ring beam is a concentric ring beam centered on the pile foundation; if it is a single unit, each ring beam is connected sequentially to form a vortex-shaped ring beam centered on the pile foundation.

[0008] Furthermore, the shape of the ring beam is determined based on the flow field characteristics of the sea area where the pile foundation is located: for reciprocating flow fields with concentrated flow direction, the ring beam shape is designed as an ellipse; for non-reciprocating flow fields with dispersed flow direction, it is set as a circle.

[0009] Furthermore, the number of ring beams is 3 to 10, depending on the length and width of the scour pit.

[0010] Furthermore, the ring beam can be made of reinforced concrete, steel, or membrane-bag concrete.

[0011] The technical solutions provided by the embodiments of this application may include the following beneficial effects:

[0012] 1. By using several ring beams of different heights in the pile foundation anti-scour system, the flow field around the pile is disturbed, thereby achieving the purpose of energy dissipation, weakening the flow field, reducing the sand-carrying capacity of the water flow, and thus preventing scour. At the same time, the "concave" negative topography between each ring beam is conducive to the sedimentation of suspended sediment in the water.

[0013] 2. The ring beam system itself has the effect of attracting fish while also serving the function of artificial reefs, thus having a certain degree of positive ecological benefits.

[0014] 3. The pile foundation scour prevention system adopts land prefabrication and overall hoisting in the sea, making the entire scour prevention system visible and avoiding difficulties such as underwater construction by divers and acceptance.

[0015] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] Figure 1 This is a side elevation view of an embodiment of a pile foundation scour prevention system.

[0018] Figure 2 This is a top view schematic diagram of a pile foundation anti-scour system (circular split type) according to an embodiment.

[0019] Figure 3 This is a top view schematic diagram of a pile foundation anti-scour system (elliptical split type) according to an embodiment.

[0020] Figure 4 This is a top view schematic diagram of an integrated pile foundation scour prevention system according to an embodiment.

[0021] In the diagram: 1. Pile foundation; 2. Ring beam; 3. Geotextile. Detailed Implementation

[0022] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application.

[0023] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0024] Combination Figures 1 to 4 As shown, this embodiment is a pile foundation scour prevention system, which may include several ring beams 2 centered on the pile foundation 1. The height of each ring beam gradually increases from the periphery to the center, forming a local topography with alternating concave and convex sections. This system has the functions of energy dissipation, flow disturbance, and weakening the flow field intensity and reducing the sediment-carrying capacity of the water flow, thereby achieving the purpose of scour prevention. At the same time, it also takes into account the fish-gathering effect and the function of artificial reefs. In addition, the concave negative topography between the ring beams 2 is conducive to the sedimentation of suspended sediment in the water, which is beneficial to the protection of the seabed around the pile. The bottom of the ring beams 2 is provided with a sealing geotextile 3 to further enhance scour protection.

[0025] Specifically, the shape of the ring beam 2 is determined based on the flow field characteristics of the sea area where the pile foundation 1 is located: it can be designed as a circle. Figure 2 ), oval ( Figure 3 For reciprocating flow fields with concentrated flow direction, the ring beam 2 is designed to be elliptical, with both ends of the ellipse aligned with the flow direction, which facilitates its guiding effect on the outer side of the streamline. For non-reciprocating flow fields with dispersed flow direction, it can be set to a circle.

[0026] Specifically, the number of ring beams 2 is 3 to 10, and in one embodiment there are 5 ring beams 2. In specific implementation, the number of ring beams 2 can be determined according to the length and width of the scour pit.

[0027] Specifically, ring beam 2 can be constructed using reinforced concrete, steel, or membrane-filled concrete. To increase its stiffness, reduce weight, and lower costs, reinforced concrete and membrane-filled concrete structures are recommended.

[0028] Specifically, each ring beam 2 can be either a separate unit or a single unit; if it is a separate unit, such as... Figure 2 and Figure 3 Then each ring beam 2 is a concentric ring beam 2 centered on the pile foundation 1, with each ring beam 2 having different dimensions but the same shape; if it is a single piece, such as Figure 4Then, each ring beam 2 is connected in sequence to form a vortex-shaped ring beam 2 centered on the pile foundation 1.

[0029] During construction, the ring beams 2 and geotextile 3 can be cast in a land-based processing yard and transported to the construction area by transport vessel, where they will be hoisted and laid by the construction vessel. A post-pile driving construction mode is recommended, where the pile foundation scour protection system is first hoisted to the designated position on the seabed, and then the pile foundation 1 is inserted through its pre-drilled central hole. Each ring beam 2 also serves as a guide frame for pile driving, guiding the steel pipe piles into place. The geotextile 3 and ring beams 2 are installed as a single unit on land, with the ring beams 2 also compacting the geotextile 3. Together, the geotextile 3 and ring beams 2 provide scour protection for the pile foundation 1. It should be noted that, to facilitate construction, reduce the number of hoisting operations, and improve construction efficiency, a method can be adopted... Figure 4 The integrated pile foundation anti-scour system shown is formed by integral casting, which enables one-time hoisting and placement during offshore construction, improving both operational efficiency and the accuracy of placement, thus facilitating subsequent pile driving.

[0030] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0031] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A pile foundation scour prevention system, characterized in that, It includes several ring beams centered on the pile foundation, with the height of each ring beam gradually increasing from the outer perimeter to the center, and a geotextile is installed at the bottom of the ring beam.

2. The pile foundation scour prevention system according to claim 1, characterized in that, Each ring beam can be either a separate unit or a single unit. If it is a separate unit, each ring beam is a concentric ring beam centered on the pile foundation. If it is a single unit, each ring beam is connected in sequence to form a vortex-shaped ring beam centered on the pile foundation.

3. The pile foundation scour prevention system according to claim 1, characterized in that, The shape of the ring beam is determined based on the flow field characteristics of the sea area where the pile foundation is located: for reciprocating flow fields with concentrated flow direction, the ring beam shape is designed as an ellipse; for non-reciprocating flow fields with dispersed flow direction, it is set as a circle.

4. The pile foundation scour prevention system according to claim 1, characterized in that, The number of ring beams ranges from 3 to 10, depending on the length and width of the scour pit.

5. A pile foundation scour prevention system according to claim 1, characterized in that, The ring beam can be made of reinforced concrete, steel, or membrane-bag concrete.

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