A fixed riprap device and protection method thereof

Abstract

The present invention relates to the technical field of riprap fixing equipment, and in particular to a riprap fixing device, which includes a riprap frame and a stretching net bag. The stretching net bag is provided at the bottom of the riprap frame. The riprap frame and the stretching net bag are in a trapezoidal cage structure. The riprap frame is a hollow structure. A stone throwing port is provided on the riprap frame. The stretching net bag is used to wrap a submarine cable. The stretching net bag is provided with a plurality of water-permeable holes. Based on the principle of the riprap protection method, stones are placed around the suspended submarine cable to fill the space and build it into a suitable shape to protect the submarine cable; stones are filled into the interior of the device, and the stretching net bag below wraps the submarine cable under the action of gravity. By filling the device with stones and tightly surrounding the suspended submarine cable with the device and stones, the cable no longer moves, thereby reducing loss and preventing it from being washed down by water. The dead weight and structure of the device can ensure that the cable is fixed in the ocean current for a long time, can be protected for a long time, and save costs and subsequent maintenance costs.

Description

Technical Field

[0001] The present invention relates to the technical field of riprap fixing equipment, and in particular to a riprap fixing device and a protection method thereof. Background Art

[0002] In actual projects, due to the existence of scouring, large sections of submarine cables will inevitably be suspended in the air. At this time, under the influence of water flow, the submarine cable will undergo vortex-induced vibration and bend. Under long-term bending movement, the surface and interior of the submarine cable will be worn and damaged. In addition, the suspended submarine cable is more strongly impacted by the water flow and is more likely to drive the movement of nearby submarine cables that are not suspended in the air, resulting in increased friction between the nearby submarine cables and the seabed, causing wear.

[0003] For protecting partially suspended or exposed sections of submarine cables, riprap is often used, sometimes with support and fixing. However, both methods present challenges. For areas where the seabed is too hard to bury, riprap is used to prevent damage to the cable. This method involves placing appropriately graded gravel around the cable using specialized equipment to form a protective layer. This is currently the most widely used method. Several variables must be considered when implementing riprap: variations in riprap layer thickness, rock characteristics, burial shape, burial extent, penetration of anchors of varying weights, and the initial penetration velocity of the anchor during the riprap process. Although this construction method is simple, if improper measures are taken and the pipeline is not well restrained, the pipeline will rub against the surrounding stones, causing more serious damage. Water will also flow into the gaps between the stones, forming a flow between the gaps, which will continuously wash out small sand or stones, eventually causing the protection measures to fail. At the same time, at the edge of the riprap layer, these stones will also be eroded, causing instability and deformation. Moreover, the shape or protective layer constructed by the riprap often collapses under the action of water flow, destroying the original shape and causing it to lose its effectiveness. Patent document with application number 201910895850.5 discloses a riprap protection method for protecting river-crossing pipelines, which also has the above-mentioned problem that the riprap protection is easily affected by water flow and collapses and fails.

[0004] Supported fixed protection: This type of device typically uses some device or structure to secure the cable underwater. This often involves underwater drilling or piling, which significantly increases costs and is difficult to implement on a large scale. It is also difficult to secure during severe storm surges, making it rarely used in practice. Non-piling methods use mud and sand to trap the cable, but this method is less effective and can fail in fast currents or after extended periods of operation. Summary of the Invention

[0005] In order to solve the above technical problems existing in the prior art, the present invention provides a fixed riprap device.

[0006] In order to achieve the above-mentioned purpose, the present invention proposes a fixed riprap device, comprising: a riprap frame and a stretching net bag, the stretching net bag is provided at the bottom of the riprap frame, the riprap frame and the stretching net bag form a trapezoidal cage structure, the riprap frame is a hollow structure, a slingshot is provided on the riprap frame, the stretching net bag is used to wrap the submarine cable, and the stretching net bag is provided with multiple water-permeable holes. By setting up a riprap frame and a stretching net bag, a stretching net bag is provided at the bottom of the riprap frame, the riprap frame and the stretching net bag are in a trapezoidal cage structure, the riprap frame is a hollow structure, a stone throwing port is provided on the riprap frame, the stretching net bag is used to wrap the submarine cable, and a plurality of water-permeable holes are provided on the stretching net bag. Based on the principle of the riprap protection method, stones are placed around the suspended submarine cable to fill the space and build it into a suitable shape to protect the submarine cable; stones are filled into the interior of the device, and the stretching net bag below is wrapped around the submarine cable under the action of gravity. By filling the device with stones and tightly surrounding the suspended submarine cable with the device and stones, it no longer moves. The lower support can reduce the local pressure on the submarine cable and reduce loss. It can achieve the ordinary riprap protection effect. The overall shape is restricted by the device, and the protection effect can be exerted for a long time without being washed away by the water flow. The dead weight and structure of the device can ensure that it is fixed in the ocean current for a long time, which can provide protection for a long time. It is easy to install and saves costs and subsequent maintenance costs. The purpose of hollowing out the riprap frame is to allow the incoming water to flow through the gaps, achieving a diversion effect, reducing the impact of the water flow on the device, and also contributing to the stability of the device.

[0007] As an optional embodiment, in the fixed riprap device provided by the present invention, the riprap frame includes a transverse frame and an inclined frame. The inclined frames are symmetrically arranged on either side of the transverse frame. The inclined frames are tilted downwardly away from the transverse frame at a 45° angle to ensure they are not overturned by water flow. The transverse frame and the two inclined frames form a trapezoidal structure. The provision of the transverse frame and the inclined frames increases the overall weight of the device and enhances its stability. The transverse frame and the two inclined frames form a trapezoidal structure, which provides greater stability and can also mitigate water erosion.

[0008] As an optional embodiment, in the fixed stone slinging device provided by the present invention, a connecting beam is provided on the transverse frame, and the stone slinging opening is provided on both sides of the connecting beam. The provision of the connecting beam divides the stone slinging opening into two sides, making it easier to fill the stone slinging opening with stones after the device is placed, thereby maintaining the device's balance and stability during stone slinging.

[0009] As an optional embodiment, in the riprap fixed device provided by the present invention, the tilting frame includes reinforcing crossbeams and reinforcing vertical beams, which are vertically connected to form a crisscross structure. The provision of these reinforcing crossbeams and vertical beams further enhances the stability of the device, and the crisscross structure formed by the vertical connection of the reinforcing crossbeams and vertical beams facilitates water permeability. The connecting beams, reinforcing crossbeams, and reinforcing vertical beams can be made of solid steel, with their diameters maximized to minimize breakage.

[0010] As an optional embodiment, in the fixed riprap device provided by the present invention, the front and rear sides of the stretching net are each provided with multiple circular water holes of the same diameter, and the bottom of the stretching net is provided with multiple square water holes. The circular water holes on the front and rear sides of the stretching net have a low porosity to increase its anti-extrusion ability and prevent stones from leaking out of the ends.

[0011] As an optional embodiment, in the fixed riprap device provided by the present invention, the stretch net bag is made of rubber or elastic plastic. By using a highly elastic rubber or plastic material to easily wrap around the submarine cable, the cable is protected from scouring and abrasion. The overall shape is limited by the device, ensuring long-term protection and preventing the cable from being swept away by water.

[0012] Furthermore, the present invention also provides a protection method based on the above-mentioned riprap fixed device, comprising the following steps:

[0013] S1: using an underwater detector to find out the specific location where the submarine cable is suspended, and using a crane to place the riprap fixed device into the sea;

[0014] S2: aligning the central axis of the riprap fixed device and the submarine cable;

[0015] S3: After alignment, throw stones into the slingshot above the riprap frame, and finally fill the device completely to form a riprap protective layer to wrap the submarine cable.

[0016] As an optional embodiment, in the method for protecting a fixed riprap device provided by the present invention, in step S3, fine stones are dropped into the riprap opening above the riprap frame. After the fine stones have completely surrounded and filled the submarine cable, larger-diameter stones are then added. Specifically, an underwater detector is used to determine the specific location of the suspended submarine cable. The device is then lowered into the sea using a crane on a construction vessel. Care must be taken to align the central axis of the device and the submarine cable when lowering it to the seabed. Stones are then added to the opening above the device, with smaller diameter stones being prioritized. This allows the net bag to deform to more completely enclose the submarine cable.

[0017] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: the fixed riprap device provided by the present invention is provided with a riprap frame and a stretching net bag, the bottom of the riprap frame is provided with a stretching net bag, the riprap frame and the stretching net bag form a trapezoidal cage structure, the riprap frame is a hollow structure, the riprap frame is provided with a stone throwing hole, the stretching net bag is used to wrap the submarine cable, and the stretching net bag is provided with multiple water-permeable holes. Based on the principle of the riprap protection method, stones are placed around the suspended submarine cable to fill the space and build it into a suitable shape to protect the submarine cable; stones are filled into the interior of the device, and the stretching net bag below is wrapped around the submarine cable under the action of gravity. By filling the device with stones and tightly surrounding the suspended submarine cable with the device and stones, it no longer moves. The lower support can reduce local pressure on the submarine cable and reduce loss. It can achieve the ordinary riprap protection effect. The overall shape is limited by the device, and the protection effect can be exerted for a long time without being washed away by the water flow. The weight and structure of the device can ensure that it is fixed in the ocean current for a long time, and can provide protection for a long time. It is simple to install and saves costs and subsequent maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0019] Figure 1 A schematic structural diagram of the fixed riprap device provided by the present invention;

[0020] Figure 2 A schematic structural diagram of a stretch-wrapped submarine cable of a riprap fixed device provided by the present invention;

[0021] Figure 3 This is a schematic diagram of the installation environment test of the riprap fixed device provided by the present invention;

[0022] Figure 4 A schematic diagram of the scour topography of the scour pit provided by the present invention;

[0023] Figure 5 This is a schematic diagram of the numerical simulation provided by the present invention.

[0024] [Description of Reference Numerals]

[0025] 1. Riprap frame; 11. Horizontal frame; 111. Connecting beam; 12. Inclined frame; 121. Reinforced horizontal beam; 122. Reinforced vertical beam; 2. Stretching net bag; 3. Riprap port; 4. Water hole; 5. Submarine cable. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] It should be noted that all directional indications in the embodiments of the present invention, such as first, second, up, down, left, right, front, back, etc., are only used to explain the relative position relationship, movement status, etc. between the various components in a certain specific posture as shown in the accompanying drawings. If the specific posture changes, the directional indication will also change accordingly.

[0028] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0029] The present invention provides a fixed stone riprap device, such as Figure 1-Figure 2 As shown, it includes: a riprap frame 1 and a stretching net bag 2, the stretching net bag 2 is provided at the bottom of the riprap frame 1, the riprap frame 1 and the stretching net bag 2 are a trapezoidal cage structure, the riprap frame 1 is a hollow structure, the riprap frame 1 is provided with a stone throwing port 3, the stretching net bag 2 is used to wrap the submarine cable 5, and the stretching net bag 2 is provided with multiple water-permeable holes 4. The invention provides a riprap frame 1 and a stretching net bag 2. The stretching net bag 2 is provided at the bottom of the riprap frame 1. The riprap frame 1 and the stretching net bag 2 form a trapezoidal cage structure. The riprap frame 1 is a hollow structure. The riprap frame 1 is provided with a stone throwing hole 3. The stretching net bag 2 is used to wrap the submarine cable 5. The stretching net bag 2 is provided with multiple water-permeable holes 4. Based on the principle of the riprap protection method, stones are placed around the suspended submarine cable 5 to fill the space and build a suitable shape to protect the submarine cable 5. Stones are filled into the interior of the device. The stretching net bag 2 below is wrapped around the submarine cable 5 under the action of gravity. By filling the device with stones and tightly surrounding the suspended submarine cable 5 with the device and stones, it no longer moves. The lower support can reduce local pressure on the submarine cable 5 and reduce losses. It can achieve the protection effect of ordinary riprap protection. The overall shape is restricted by the device, which can provide long-term protection without being washed away by the water flow. The deadweight and structure of the device can ensure that it is fixed in the ocean current for a long time, providing long-term protection. It is easy to install and saves costs and subsequent maintenance costs. The purpose of hollowing out the riprap frame 1 is to allow the incoming flow to flow through the gaps, thereby achieving a diversion effect, reducing the impact of the water flow on the device, and also contributing to the stability of the device.

[0030] like Figure 2 As shown, in the fixed riprap device provided by the present invention, the riprap frame 1 comprises a transverse frame 11 and an inclined frame 12. The inclined frames 12 are symmetrically positioned on either side of the transverse frame 11. The inclined frames 12 are tilted downward, away from the transverse frame 11, at a 45° angle to prevent them from being overturned by water flow. The transverse frame 11 and the two inclined frames 12 form a trapezoidal structure. The transverse frame 11 and the two inclined frames 12 increase the overall weight of the device and enhance its stability. The trapezoidal structure formed by the transverse frame 11 and the two inclined frames 12 provides greater stability and mitigates water erosion. The transverse frame 11 and the inclined frames 12 can be designed as solid steel structures, with their diameters maximized to minimize breakage.

[0031] like Figure 1 As shown, in the fixed stone slinging device provided by the present invention, the transverse frame 11 is provided with a connecting beam 111, and the stone slinging opening 3 is provided on both sides of the connecting beam 111. The provision of the connecting beam 111 divides the stone slinging opening 3 into two sides for stone slinging, making it easier to fill the stone slinging opening with stones after the device is placed, thereby maintaining the device's balance and stability during stone slinging.

[0032] Furthermore, in the riprap fixed device provided by the present invention, the tilting frame 12 includes a reinforcing crossbeam 121 and a reinforcing vertical beam 122, which are vertically connected to form a crisscross structure. The provision of the reinforcing crossbeam 121 and the reinforcing vertical beam 122 further enhances the stability of the device, and the crisscross structure formed by the vertical connection of the reinforcing crossbeam 121 and the reinforcing vertical beam 122 facilitates water permeability. Specifically, the connecting beam 111, the reinforcing crossbeam 121, and the reinforcing vertical beam 122 can be made of solid steel, with the diameter being maximized to minimize breakage.

[0033] Furthermore, in the fixed riprap device provided by the present invention, the front and rear sides of the stretching net 2 are each provided with a plurality of circular water-permeable holes 4 of the same diameter, and the bottom of the stretching net 2 is provided with a plurality of square water-permeable holes 4. The circular water-permeable holes 4 on the front and rear sides of the stretching net 2 have a relatively low porosity to increase its anti-extrusion capability and prevent stones from leaking out of the ends.

[0034] In addition, the stretching net bag 2 is made of rubber or elastic plastic. By using rubber or plastic material with good shrinkage to wrap the submarine cable 5, the submarine cable 5 is protected from scouring and wear. The overall shape is limited by the device, and the protective effect can be exerted for a long time without being washed away by water.

[0035] Furthermore, the present invention also provides a submarine cable protection method based on the above-mentioned riprap fixed device, comprising the following steps:

[0036] S1: Using an underwater detector to find out the specific location where the submarine cable 5 is suspended, and using a crane to place the riprap fixed device into the sea;

[0037] S2: Aligning the central axis of the riprap fixed device and the submarine cable 5;

[0038] S3: After alignment, stones are thrown into the slinghole 3 above the riprap frame 1, and the device is finally completely filled to form a riprap protective layer to wrap the submarine cable 5.

[0039] Furthermore, in the submarine cable protection method for a fixed riprap device provided by the present invention, in step S3, fine stones are dropped into the riprap opening 3 above the riprap frame 1. After the fine stones have completely surrounded and filled the submarine cable 5, larger-diameter stones are then added. Specifically, the specific location of the suspended submarine cable 5 is determined using an underwater detector, and the device is lowered into the sea using a crane on a construction vessel. Care must be taken to align the central axis of the device and the submarine cable 5 when lowering it to the seabed. Stones are then added to the opening above the device, with smaller diameter stones being preferred. This allows the net bag to deform to more completely enclose the submarine cable 5.

[0040] The design principle of the riprap fixed device provided by the present invention is to take into account the scouring environment around the suspended submarine cable 5, and to ensure that the device can be placed in the scouring pit without any unreasonable placement, such as if the size is too large and crosses the scouring pit, and to ensure that the device can function and remain stable without failure. The design size is determined by conducting experiments and numerical simulations. Figure 3 As shown, the submarine cable 5 is laid flat on the seabed. The upstream water flows vertically through the submarine cable 5 and flows downstream, forming a scouring pit around the submarine cable 5. After the scouring reaches equilibrium, the scouring pit profile data is measured to draw a dimensionless topographic map, as shown in Figure 4 As shown in Figure 2, considering that different water depths will also affect the scouring situation, the software is used to perform numerical simulations on working conditions with different water depths to obtain numerical simulation results, such as Figure 5 As shown, it can be seen that the depth and range of scour equilibrium do not change significantly with water depth. The impact of different water depths on scour is mainly reflected in the downstream. The deeper the water depth, the closer the downstream accumulation is to the submarine cable 5 and the higher the height is. When the water depth continues to increase, the change will become smaller and will eventually not change with the increase of scour depth. The accumulation behind H=3D and H=4D is basically the same. Considering the actual marine environment and engineering conditions, submarine cable 5 is mostly laid near the coast. The direction of water flow in the near coast will change forward and backward due to the influence of tides. Therefore, there is usually no accumulation around this part of submarine cable 5. The morphology on the left and right sides of the scour pit is similar to that of the submarine cable 5. Figure 4 The scouring pattern in the middle and upper reaches is the same. When designing the device, it should be designed according to this scouring pattern.

[0041] In order to make the device able to be placed in the scouring pit, and to facilitate the net bag to wrap the submarine cable 5 after the stone is put in, the bottom size of the net bag must be smaller than the scouring pit. Figure 4 The bottom length can be set to four times the diameter of the submarine cable 5; this allows the net bag to wrap around the submarine cable 5 after the stone is placed. To ensure stability, the device is designed to fit into the scouring pit, limiting its movement angle to 45°. This smaller angle ensures it will not be overturned by the current. The principle of overall protection is to stabilize the submarine cable 5 through the device's restraining and filling effects. To achieve a better restraining effect, in addition to the size and angle design mentioned above, the weight of the entire device needs to be increased as much as possible to achieve greater stability.

[0042] It should be understood that the above description of the specific embodiments of the present invention is merely for the purpose of illustrating the technical approach and features of the present invention. Its purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. However, the present invention is not limited to the above-described specific embodiments. Any changes or modifications made within the scope of the claims of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A fixed riprap device, characterized in that: The invention comprises a riprap frame (1) and a stretching net bag (2), wherein the stretching net bag (2) is provided at the bottom of the riprap frame (1), the riprap frame (1) and the stretching net bag (2) are in a trapezoidal cage-like structure, the riprap frame (1) is a hollow structure, a slinging hole (3) is provided on the riprap frame (1), the stretching net bag (2) is used for wrapping a submarine cable (5), and a plurality of water-permeable holes (4) are provided on the stretching net bag (2).

2. The riprap fixed device according to claim 1, characterized in that: The riprap frame (1) comprises a transverse frame (11) and an inclined frame (12). The inclined frames (12) are symmetrically arranged on both sides of the transverse frame (11). The inclined frames (12) are arranged obliquely downward in a direction away from the transverse frame (11). The transverse frame (11) and the two inclined frames (12) form a trapezoidal structure.

3. The riprap fixed device according to claim 2, characterized in that: A connecting beam (111) is provided on the transverse frame (11), and the slingshot (3) is provided on both sides of the connecting beam (111).

4. The riprap fixed device according to claim 2, characterized in that: The inclined frame (12) comprises a reinforcing crossbeam (121) and a reinforcing vertical beam (122), wherein the reinforcing crossbeam (121) and the reinforcing vertical beam (122) are vertically connected to form a well-shaped structure.

5. The riprap fixed device according to claim 1, characterized in that: The front and rear sides of the stretching net bag (2) are respectively provided with a plurality of circular water-permeable holes (4) of the same diameter, and the bottom of the stretching net bag (2) is provided with a plurality of square water-permeable holes (4).

6. The riprap fixed device according to claim 1, characterized in that: The stretching net bag (2) is made of rubber or elastic plastic.

7. The riprap fixed device according to claim 1, characterized in that: The riprap fixed device is placed in the scouring pit, and the bottom side length of the riprap fixed device is four times the diameter of the submarine cable (5).

8. A method for protecting a riprap fixed device according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: using an underwater detector to find out the specific location of the suspended submarine cable (5), and using a crane to place the riprap fixed device into the sea; S2: aligning the central axis of the riprap fixed device and the submarine cable (5); S3: After alignment, stones are thrown into the slingshot (3) above the riprap frame (1), and the device is finally completely filled to form a riprap protective layer to wrap the submarine cable (5).

9. The method for protecting a riprap fixed device according to claim 8, characterized in that: In step S3, fine stones are thrown into the stone throwing port (3) above the stone throwing frame (1), and after the fine stones have completely surrounded and filled the submarine cable (5), large-diameter stones are started to be filled.

Images