Flexible energy dissipation, flow diversion and anti-scour device and application method

Abstract

The present invention discloses a flexible energy dissipation and diversion anti-scour device and an application method, which is used for local scour protection of pile foundations, and includes a flexible sheath, a rigid guide plate and a flexible pad, wherein the flexible sheath is wrapped on the pile column, the rigid guide plate is arranged on the top of the flexible sheath, and the flexible pad is laid around the pile foundation. The present invention utilizes the flexible sheath to absorb the kinetic energy of the incoming flow and reduce the flow velocity of the incoming flow; utilizes the rigid guide plate to block and disinfect the submerged current from the water-facing surface of the pile foundation, changes its size and direction, forces the descending water flow to flow to both sides, and reduces the strength of the horseshoe vortex; utilizes the flexible pad to protect the bottom of the foundation, reduces the impact energy of the descending water flow, and makes the incoming flow energy at the bottom of the sea mainly act on the flexible pad, thereby avoiding the movement and erosion of the seabed soil by the incoming flow; and the flexible pad has good synergistic adaptability with different pile foundation seabeds, and can be applied to various complex seabed surfaces.

Description

Technical Field

[0001] The invention relates to a foundation protection device for a fixed structure above water and an application method thereof, in particular to a flexible energy dissipation, flow diversion and anti-scour device for a pile foundation, belonging to the technical field of marine engineering and water conservancy engineering. Technical Background

[0002] The pile foundation mentioned in the present invention mainly refers to the foundation part of the piers or piles driven into the seabed as support for bridges, docks, plank roads or fixed platforms. When building wind turbine foundations, bridges, jacket platforms, jack-up platforms and other fixed structures on the water in shallow seas and intertidal zones, the soil around the foundations will be scoured due to the action of tides and ocean currents, taking away the mud and sand around the piles and foundations, resulting in a reduction in the bearing capacity of the pile body. When the pile foundation is scoured and exposed to a certain extent, it may cause the foundation to tilt, and even have the serious consequence of the overall collapse of the structure. Therefore, in order to protect the safety of water buildings, scour protection measures must be taken for the pile foundations.

[0003] The presence of the foundation causes the acceleration of the water flow, causing the laminar boundary layer to be disturbed and separated, and generating vortices that carry away the surrounding sediments. The vortex is a complex integrated water flow structure, which includes the downward flow of the water on the water surface, the horseshoe vortex formed by the flow around the two sides near the bed surface, and the wake vortex formed by the separation of the boundary layers on both sides. Small vortices are released near the bed surface on both sides of the pile and behind the pile platform.

[0004] The existing pile foundation scour protection methods mainly include underwater riprap, expanded foundation protection, concrete sinking pad, pile body slit protection, pile front row protection and submerged sill protection. In practice, although underwater riprap, expanded foundation protection and concrete sinking pad have achieved certain scour prevention and control effects, solid objects such as underwater riprap are much more rigid than the seabed surface, and they still have serious scour on the sediment on the seabed, resulting in the emergence of the "secondary scour" problem on the seabed. The seawater continuously carries away the sediment, and the stones sink. After a period of time, the stones will sink below the mud surface and cannot play a protective role. Therefore, it is necessary to continuously riprap to maintain the mud surface elevation. To ensure that the scour does not develop to the foundation within the service life, a large area around the foundation needs to be treated, which is expensive and difficult to maintain later. Pile body slit protection, pile front row protection and submerged sill protection are limited by the flow direction of the water flow. They are mainly suitable for the scour protection of pile piers in rivers. In the offshore environment, the protection effect is not obvious, and it is laborious, time-consuming and requires a large amount of materials. Summary of the invention

[0005] In order to solve the deficiencies of the prior art, the present invention aims to provide a flexible energy dissipation and flow diversion anti-scouring device and an application method. The device can effectively protect the pile foundation from being scoured, and can be applied to rivers and offshore areas with complex flow fields.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A flexible energy dissipation, diversion and anti-scour device comprises: a flexible sheath, a rigid guide plate, a flexible pad, a short casing, an anchor rope and an anchor, wherein the flexible sheath is in a rectangular structure, two corresponding sides of the flexible sheath are overlapped to form a cylindrical structure, the rigid guide plate is composed of an annular protective ring and a short casing, the short casing and the flexible sheath are overlapped to form a cylindrical structure with the top forming a binding fit, the flexible pad is in a disc shape, the middle of the flexible pad has a hole which is the same as the cylindrical structure after the flexible sheath is overlapped, the inner edge of the flexible pad is overlapped with the flexible sheath to form a cylindrical structure with the outer periphery of the bottom fixedly connected, and the anchor is connected to the outer edge of the flexible pad through the anchor rope.

[0008] The above scheme further comprises:

[0009] The two corresponding overlapping edges of the flexible sheath are connected by nylon buckles or zippers, and the inner edge of the flexible pad is overlapped with the flexible sheath to form an outer periphery of the bottom of the tubular structure, which is connected by nylon buckles or zippers, sewing with strings, and binding with tying ropes.

[0010] The flexible protective pad is made of a whole piece or a plurality of pieces of flexible material which are overlapped and sewn together by nylon buckles or zippers or cords.

[0011] The flexible sheath and the flexible pad are both made of energy absorbing materials, including silicone rubber or polyurethane.

[0012] The zipper, cord, anchor rope and lashing rope are all made of UV-resistant, high-strength, corrosion-resistant and lightweight non-metallic materials.

[0013] An application method using the flexible energy dissipation and diversion anti-scour device described above, comprising: a flexible sheath is wrapped around a pile column through a nylon buckle or a zipper or a rope connection, a rigid guide plate is arranged on the top of the flexible sheath, a flexible pad is laid around the pile foundation, an inner edge of the flexible pad is connected to the flexible sheath through a nylon buckle, a zipper, a rope or is tied to the pile leg through a binding rope, one end of the anchor rope is connected to the flexible pad material near the outer edge, and the other end is set on the anchor, the anchor is driven into the seabed soil at a specified depth through an anchor grab, so that the outer edge of the flexible pad naturally droops and is perpendicular to the scour surface to form an umbrella-shaped protective net.

[0014] Another application method of the aforementioned flexible energy dissipation, diversion and anti-scour device includes: a flexible sheath is wrapped around a pile column through a nylon buckle or a zipper or a rope connection, a rigid guide plate is arranged on the top of the flexible sheath, a slope-shaped protective structure is filled around the pile foundation, a flexible pad is laid around the pile foundation, the inner edge of the flexible pad is connected to the flexible sheath through a nylon buckle, a zipper, a rope or is tied to the pile leg through a binding rope, one end of the anchor rope is connected to the flexible pad material near the outer edge, and the other end is set on the anchor, and the anchor is driven into the seabed soil at a specified depth through an anchor grab, so that the outer edge of the flexible pad naturally droops and is perpendicular to the scour surface to form an umbrella-shaped protective net.

[0015] The technical principle of the present invention is: through in-depth investigation of the internal mechanism of scour formation and development, starting from the disturbed water flow structure, using the energy dissipation concept, using porous soft energy-absorbing materials, so that it can absorb the kinetic energy of the incoming flow, weaken the intensity of the incoming flow, and effectively reduce the flow rate of the incoming flow; change the surrounding flow field distribution, prevent the water flow from moving downward, reduce the speed and energy of the submerged current, and change the flow direction of part of the incoming flow after passing through the guide plate; use flexible bottom protection materials with much smaller rigidity than the seabed surface, so that the wave and current force acts more on the protective device, reducing the scouring effect of the wave and current on the seabed, thereby avoiding the hollowing of sand and soil at the edge of the flexible protective pad. The present invention is a brand-new active protection device for pile foundation scour proposed on the basis of traditional treatment methods.

[0016] Due to the adoption of the above technical solution, the present invention has the following advantages compared with the prior art:

[0017] 1. The present invention has good anti-scour effect, and the dynamic characteristics of the structure will not change during service;

[0018] 2. The present invention can play a wave-breaking role regardless of the direction of the water flow. It is suitable for the scouring protection of pile piers in rivers, and can also be widely used in marine engineering structures under harsh marine environmental conditions, such as the scouring protection of pile foundations of oil platforms and bridges, wind power generation platforms, etc. in marine oil and gas exploitation;

[0019] 3. Good economic benefits. It can be used for the protection of new structures and the scouring and repair of existing structures. It requires a one-time investment, low subsequent maintenance costs, and is easy to maintain. According to monitoring conditions, when the material is damaged or aged, it can be easily replaced;

[0020] 4. It can reduce the number of platform scouring tests and improve the safety and stability of the structure;

[0021] 5. The present invention has a simple structure, convenient construction, low cost, and the flexible material is easy to transport and store.

[0022] The present invention reduces the incoming flow velocity acting on the pile column and the speed and energy of the downflow through the combination of a flexible sheath, a rigid guide plate and a flexible pad, thereby avoiding the start of sediment around the pile foundation, overcoming the shortcomings of the existing technology for pile foundation scour prevention, and providing a flexible pile foundation scour protection device that can be quickly and easily applied on both the seabed and the riverbed. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the cross-sectional structure of the flexible energy dissipation and diversion anti-scour device embodiment 1

[0024] Figure 2 is the elevation view of the rigid guide plate ( Figure 1 (Partial enlarged view)

[0025] Figure 3 Schematic diagram of the flexible pad

[0026] Figure 4 Schematic diagram of the cross-sectional structure of the flexible energy dissipation and diversion anti-scour device embodiment 2

[0027] Figure 5 Plan view of a rigid guide plate

[0028] The marks in the figure are as follows:

[0029] 1 flexible sheath, 2 rigid guide plate (including 4 annular guard ring, 5 short casing), 3 flexible pad, 6 nylon fastener, 7 anchor rope, 8 anchor, 9 pile leg, 10 seabed surface, 11 structural reinforcement ribs, 12 sloped protective structure. DETAILED DESCRIPTION

[0030] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the following embodiments.

[0031] Example 1, refer to the attached Figure 1-3 A flexible energy dissipation and diversion anti-scour device comprises: a flexible sheath 1, a rigid guide plate 2, a flexible cushion 3, an annular guard ring 4, a short casing 5, an anchor rope 7 and an anchor 8. The flexible sheath 1 is a rectangular structure, two corresponding sides of the flexible sheath 1 are overlapped to form a cylindrical structure, the rigid guide plate 2 is composed of an annular guard ring 4 and a short casing 5, the short casing 5 and the flexible sheath 1 are overlapped to form a cylindrical structure with the top of the cylindrical structure forming a binding fit, the flexible cushion 3 is a disc, the flexible cushion 3 has a hole in the middle that is the same as the cylindrical structure after the flexible sheath 1 is overlapped, the inner edge of the flexible cushion 3 is overlapped with the flexible sheath 1 to form a cylindrical structure with the outer periphery of the bottom fixedly connected, and the anchor 8 is connected to the outer edge of the flexible cushion 3 through the anchor rope 7.

[0032] Further:

[0033] The two corresponding edges of the flexible sheath 1 are connected by nylon buckle 6 or zipper, and the inner edge of the flexible pad 3 is overlapped with the flexible sheath 1 to form a tubular structure. The outer periphery of the bottom is connected by nylon buckle 6 or zipper, and the cord is sewn or tied with a binding rope.

[0034] The flexible protective pad 3 is made of a whole piece or multiple pieces of flexible material which are overlapped by nylon buckles or zippers or cords.

[0035] The flexible sheath 1 and the flexible pad 3 are both made of energy absorbing materials, including silicone rubber or polyurethane.

[0036] The zipper, cord, anchor rope and lashing rope are all made of UV-resistant, high-strength, corrosion-resistant and lightweight non-metallic materials.

[0037] Embodiment 2: An application method of the aforementioned flexible energy dissipation, diversion and anti-scour device, comprising: a flexible sheath is connected and wrapped on a pile column by means of nylon straps, zippers or cords, a rigid guide plate is arranged on the top of the flexible sheath, a flexible protective pad is laid around the pile foundation, an inner edge of the flexible protective pad is connected to the flexible sheath by means of nylon straps, zippers or cords or is tied to the pile leg by means of binding ropes, one end of the anchor rope is connected to the flexible protective pad material near the outer edge, and the other end is arranged on the anchor, the anchor is driven into the seabed soil at a specified depth by means of an anchor grab, so that the outer edge of the flexible protective pad naturally droops and is perpendicular to the scour surface to form an umbrella-shaped protective net.

[0038] Embodiment 3: An application method utilizing the aforementioned flexible energy dissipation, diversion and anti-scour device, comprising: a flexible sheath is wrapped around a pile column through a nylon fastener or a zipper or a rope connection, a rigid guide plate is arranged on the top of the flexible sheath, a slope-shaped protective structure is filled around the pile foundation, a flexible protective pad is laid around the pile foundation, an inner edge of the flexible protective pad is connected to the flexible sheath through a nylon fastener, a zipper or a rope, or is tied to the pile leg through a binding rope, one end of the anchor rope is connected to the flexible protective pad material near the outer edge, and the other end is arranged on the anchor, the anchor is driven into the seabed soil at a specified depth through an anchor grab, so that the outer edge of the flexible protective pad naturally droops and is perpendicular to the scour surface to form an umbrella-shaped protective net.

[0039] Example 4: Figure 1 As shown, the flexible energy dissipation, flow diversion and anti-scour device provided by the present invention is composed of a flexible sheath 1, a rigid flow guide plate 2 and a flexible protective pad 3.

[0040] The flexible sheath 1 is made of energy-absorbing materials such as silicone rubber and polyurethane with large deformation capacity, small rigidity, large damping coefficient and corrosion resistance. The two sides of the flexible sheath 1 are butt-jointed or overlapped on the pile legs 9 using the Velcro 6, and the top position of the flexible sheath 1 is fixed using a rigid guide plate 2. The function of the flexible sheath 1 is to absorb the energy of the incoming flow, reduce the speed of the incoming flow, and thus reduce the speed of the descending flow.

[0041] The rigid guide plate 2 is arranged on the top of the flexible sheath 1 to maintain structural stability under the action of marine environmental forces, such as Figure 2 As shown, the rigid guide plate 2 is composed of a combination of an annular retaining ring 4 and a short casing 5 welded together, and is arranged at the top of the flexible sheath 1 through the short casing 5, and the short casing 5 also plays the role of fixing the position of the flexible sheath 1. The function of the rigid guide plate 2 is to block the submerged current from the water-facing surface of the pile leg 9, change its size and direction, and force the descending water flow to flow to both sides.

[0042] like Figure 3 As shown, the flexible protective pad 3 is laid on the seabed 10 around the pile foundation. The flexible protective pad 3 can be made of energy-absorbing materials such as silicone rubber and polyurethane with large deformation capacity, small rigidity, large damping coefficient and corrosion resistance. The material can be the same as the flexible jacket 1, but the rigidity needs to be less than the rigidity of the seabed soil. The flexible protective pad 3 is composed of a whole piece or multiple pieces of flexible material. The multiple pieces of flexible material are arranged axially in a circular shape to form the flexible protective pad 3. The side of the flexible protective pad 3 can be connected or overlapped into a whole using Velcro 6, that is, a disc-shaped flexible protective pad 3 is formed. The inner edge of the flexible protective pad 3 is tied to the root of the pile leg 9 by a tying rope. The function of the flexible protective pad 3 is to protect the bottom of the foundation, prevent the fluid around the pile foundation from directly acting on the bottom of the pile foundation, and protect the mud and sand under the flexible protective pad 3 from being washed away. The flexible material can also reduce the scouring energy of the descending water flow, avoid the erosion vortex, horseshoe vortex formed by the pile leg 9 in the flow field, and the upper downward flow caused by the incoming flow direction, which will cause the pile leg 9 to contact with the seabed silt 10, weaken the vortex erosion, and play a role in scouring protection. Even if some silt is rushed up, in the case of forming a ring protection for the pile foundation, the silt is deposited around the flexible protective pad 3, preventing the silt from moving to other places from the flexible protective pad 3.

[0043] The anchor rope 7 is a rope made of UV-resistant, high-strength, corrosion-resistant and lightweight non-metallic material. One end of the anchor rope 7 is connected to the flexible cushion 3 near the outer edge, and the other end is set on the anchor 8. The flexible cushion 3 is not overturned by waves and currents through the pulling action of the anchor rope 7. The anchor 8 is driven into the seabed soil at a specified depth through the anchor gun. The outer edge of the flexible cushion 3 droops naturally and is perpendicular to the scouring surface to form an umbrella-shaped protective net.

[0044] Embodiment 5: Figure 4The embodiment 5 shown is improved on the basis of the embodiment 4. In order to further change the direction of the water flow at the bottom of the pile foundation, reduce the erosion vortex and horseshoe vortex formed by the pile legs in the flow field, reduce the strength of the wake and the wake vortex, and further reduce the effect of the incoming flow on the seabed soil, a slope-shaped protective structure 12 is formed around the bottom of the pile by prefabricated concrete or taking seabed soil from the surrounding area, and then a flexible protective pad 3 is laid on the slope-shaped protective structure 12. The rest of the composition and implementation of the protective device are similar to those of the embodiment 1.

[0045] Figure 5 The plan view of the rigid guide plate. The upper and lower ends of the annular retaining ring 4 are reinforced with reinforcing ribs 11.

[0046] The present invention is only described with reference to the above-mentioned embodiments. The structure, location and connection of each component may be changed. On the basis of the technical solution of the present invention, any improvement and equivalent transformation of individual components according to the principle of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A flexible energy dissipation and flow diversion anti-scour device, characterized in that include: A flexible sheath, a rigid guide plate, a flexible cushion, an anchor rope and an anchor, wherein the flexible sheath is in a rectangular structure, two corresponding sides of the flexible sheath are overlapped to form a cylindrical structure, the rigid guide plate is composed of an annular protective ring and a short casing, the short casing is overlapped with the flexible sheath to form a cylindrical structure with the top thereof forming a binding fit, the flexible cushion is in a disc shape, the middle of the flexible cushion has a hole identical to that of the cylindrical structure after the flexible sheath is overlapped, the inner edge of the flexible cushion is fixedly connected to the outer periphery of the bottom of the cylindrical structure formed after the flexible sheath is overlapped, and the anchor is connected to the outer edge of the flexible cushion through an anchor rope; the flexible cushion is composed of a whole piece or multiple pieces of flexible materials overlapped by nylon buckles or zippers, or stitched with strings; the flexible sheath and the flexible cushion are both made of energy-absorbing materials, including silicone rubber or polyurethane; the rigidity of the flexible cushion is less than that of the seabed soil; The two corresponding overlapping edges of the flexible sheath are connected by nylon buckles or zippers or strings, and the bottom outer periphery of the tubular structure formed by overlapping the inner edge of the flexible pad and the flexible sheath is connected by nylon buckles or zippers, string sewing, and binding rope binding.

2. According to claim 1, the flexible energy dissipation and flow diversion anti-scour device is characterized by: The zipper, cord, anchor rope and lashing rope are all made of UV-resistant, high-strength, corrosion-resistant and lightweight non-metallic materials.

3. An application method of the flexible energy dissipation, flow diversion and anti-scour device according to claim 1, characterized in that: The flexible sheath is connected and wrapped on the pile column through nylon buckles, zippers or ropes, the rigid guide plate is arranged on the top of the flexible sheath, the flexible pad is laid around the pile foundation, the inner edge of the flexible pad is connected to the flexible sheath through nylon buckles, zippers and ropes or is tied to the pile leg through lashing ropes, one end of the anchor rope is connected to the flexible pad material near the outer edge, and the other end is set on the anchor, and the anchor is driven into the seabed soil at a specified depth through an anchor gun, so that the outer edge of the flexible pad naturally droops and is perpendicular to the scouring surface to form an umbrella-shaped protective net.

4. An application method of the flexible energy dissipation, flow diversion and anti-scour device according to claim 1, characterized in that: The flexible sheath is connected and wrapped on the pile column through Velcro or zippers and ropes, the rigid guide plate is arranged on the top of the flexible sheath, the slope-shaped ring protection structure is filled around the pile foundation, the flexible pad is laid around the pile foundation, the inner edge of the flexible pad is connected to the flexible sheath through Velcro, zippers and ropes or is tied to the pile leg through binding ropes, one end of the anchor rope is connected to the flexible pad material near the outer edge, and the other end is set on the anchor, and the anchor is driven into the seabed soil at a specified depth through an anchor gun, so that the outer edge of the flexible pad naturally droops and is perpendicular to the scouring surface to form an umbrella-shaped protective net.

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