Anti-scour device and anti-scour method for crossing position of submarine pipe cable

Abstract

The invention discloses an anti-scour device and an anti-scour method for a crossing position of a submarine pipe cable, and belongs to the technical field of ocean engineering. The anti-scour device for the crossing position of the submarine pipe cable comprises an anti-scour protection cover, and a plurality of pile foundations are connected to the bottom face of the anti-scour protection cover. A plurality of rows of flow restraining plates are evenly distributed on the surface of the anti-scouring protective cover in the radial direction, and each flow restraining plate is composed of an annular flow restraining plate body and a radial flow restraining plate body which are perpendicularly connected. A plurality of pipeline penetrating holes are symmetrically formed in the edge of the anti-scouring protection cover. According to the invention, suspension caused by sediment scouring below the submarine pipe cable at the crossing point can be prevented, and suspension below the pipe cable around the crossing point of the submarine pipe cable can also be prevented. The device can be recycled, and is convenient to mount and dismount, green, environment-friendly, high in corrosion resistance and low in cost.

Description

Technical Field

[0001] The invention relates to the field of marine engineering technology, and in particular to an anti-scouring device and an anti-scouring method for a submarine pipe and cable crossing point. Background Art

[0002] After the submarine pipeline is laid on the seabed, the distribution of the submarine flow field will change, the local water flow velocity will increase, and the mud and sand around the submarine cable will be washed away to form a suspended span. When the length of the suspended span increases to a certain extent, the cable will lose its effective support function, which is very easy to cause vortex-induced vibration, causing fatigue damage to the cable, resulting in serious economic losses and environmental pollution. Especially at the intersection of the cable and the pipe, the general practice is to cover the lower cable with a layer of cement blocks, then lay the upper cable and pipe on top of it, and finally cover the upper cable and pipe with a layer of cement blocks. In this way, the height of the cable and pipe on the seabed surface is greater, and it is easier to form a suspended span caused by scouring. At present, the commonly used submarine cable and pipe scouring protection technologies mainly include riprap, filling sandbags, piling, concrete sinking pads, etc., but the common disadvantages of these methods are huge construction, high investment, and easy to have "secondary scouring" problems. In recent years, flexible protection technologies such as artificial grass and bionic seaweed have also been developed, but this technology is easy to fall under the action of strong water flow and has poor reliability.

[0003] Therefore, developing a device and method that can effectively suppress the scouring problem at the intersection of submarine cables and reduce the risk of suspension and vortex-induced vibration of cables at the intersection is of great significance to improving the safety of submarine cable operation. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an anti-scouring device and an anti-scouring method for a submarine cable crossing point.

[0005] In a first aspect, the present invention provides an anti-scouring device for a submarine cable crossing point, which is realized by adopting the following technical solution.

[0006] A scour prevention device for a submarine cable crossing includes an scour prevention cover, a plurality of pile foundations are connected to the bottom surface of the scour prevention cover; a plurality of rows of flow suppression plates are evenly distributed radially on the surface of the scour prevention cover, the flow suppression plates are composed of vertically connected annular flow suppression plates and radial flow suppression plates; and a plurality of pipeline perforations are symmetrically formed on the edge of the scour prevention cover.

[0007] Furthermore, the anti-scour protection cover is a spherical arc surface structure.

[0008] Furthermore, 8 rows of flow suppression plates are distributed on the surface of the anti-scour protection cover, and the angle between each two adjacent rows of flow suppression plates is 45°.

[0009] Furthermore, the annular flow suppression plate and the radial flow suppression plate have the same height.

[0010] Furthermore, the pile foundation is a cylindrical structure, with four piles in total, which are evenly distributed in the gaps between several rows of flow suppression plates.

[0011] Furthermore, a raised lifting lug is provided directly above the anti-scour protection cover.

[0012] In a second aspect, the present invention provides a method for preventing scouring at the crossing point of submarine cables and pipes, which is achieved by adopting the following technical solution.

[0013] An anti-scouring method using the above-mentioned anti-scouring device at the crossing point of submarine cables and pipes comprises the following steps:

[0014] S1. Determine the location of the intersection of submarine pipes and cables, use a crane to hook the lifting lug, and lower the anti-scour device to the intersection of submarine pipes and cables;

[0015] S2. Adjust the direction of the anti-scour device underwater so that the position of the pipeline perforation is just above the cross-cable;

[0016] S3. Pile insertion and stabilization: Use mud blowing equipment to blow mud in a small area at the pile foundation location. After the pile foundation is inserted into the seabed, level the entire device and finally backfill at the pile foundation location to stabilize the device.

[0017] The present invention achieves the following beneficial effects.

[0018] The anti-scouring device and anti-scouring method for the intersection of submarine pipes and cables of the present invention can effectively prevent the suspension caused by the scouring of mud and sand under the submarine pipes and cables at the intersection point; the annular flow suppression plate and the radial flow suppression plate of the present invention can block and slow down the bottom currents in all directions, thereby reducing the scouring effect of the bottom current on the mud and sand at the surrounding pipes and cables, and increasing the silting effect of the mud and sand entrained in the current, thereby preventing the formation of suspension under the pipes and cables around the intersection of submarine pipes and cables. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a front view of the present invention;

[0020] Figure 2 It is a top view of the present invention.

[0021] Among them: 1. Anti-scour protection cover; 2. Annular flow suppression plate; 3. Radial flow suppression plate; 4. Pile foundation; 5. Pipeline perforation; 6. Center point; 7. Lifting lug; 8. Seabed. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be clearly and completely described below through specific implementation methods.

[0023] like Figure 1-2As shown, an anti-scour device for the crossing of submarine pipes and cables includes an anti-scour protection cover 1, a flow suppression plate, a pile foundation 4, a pipeline perforation 5, and a lifting lug 7.

[0024] The anti-scour protection cover 1 is a spherical arc surface structure, which is fixed on the seabed 8 by inserting the pile foundation 4 into the seabed 8. Specifically, the pile foundation 4 is a cylindrical structure, with four piles in total, which are evenly distributed in the gaps between each row of flow suppression plates and vertically inserted into the seabed 8.

[0025] Preferably, the height of the anti-scour protection cover 1 of the present application depends on the total height of the submarine cable protruding from the seabed 8 at the crossing point, and should be at least 30 cm higher than the total height; the coverage radius of the anti-scour protection cover 1 on the seabed 8 depends on the radius of the submarine cable. The distance between the pile foundation 4 and the edge of the anti-scour protection cover 1 depends on the coverage radius of the anti-scour protection cover 1 on the seabed 8, preferably in the middle position close to the edge; the depth of the pile foundation 4 inserted into the seabed 8 depends on the soil conditions at the crossing point of the submarine cable, and the depth of mud in sandy soil is greater than that in clay soil.

[0026] The surface of the anti-scour protection cover 1 is evenly distributed with 8 rows of flow suppressors radially, and the angle between each two adjacent rows of flow suppressors is 45°; the number of flow suppressors in each row can be adjusted according to the size of the anti-scour protection cover 1 and the environmental conditions at the intersection of the submarine pipe and cable; the flow suppressors are distributed in the anti-scour protection cover 1 in a centrally symmetrical and axially symmetrical structure. Each flow suppressor is composed of an annular flow suppressor 2 and a radial flow suppressor 3, the annular flow suppressor 2 and the radial flow suppressor 3 are vertically connected and have the same height, and the height of the annular flow suppressor 2 and the radial flow suppressor 3 can be adjusted according to the environmental conditions at the intersection of the submarine pipe and cable. The distance between the flow suppressor and the center point 6 can be adjusted according to the length of the annular flow suppressor 2, and the center point 6 is located directly above the intersection of the submarine pipe and cable.

[0027] A plurality of pipeline perforations 5 are formed on the edge of the anti-scour protection cover 1. The pipeline perforations 5 are axially symmetrical elliptical arcs. The positions and sizes of the pipeline perforations 5 depend on the size of the crossing pipe cables and the crossing angle. The positions of the pipeline perforations 5 in the present application should avoid the positions of the annular flow suppression plate 2 and the radial flow suppression plate 3 as much as possible.

[0028] A raised lifting lug 7 is provided just above the anti-scour protection cover 1 so as to lift the anti-scour protection cover 1 .

[0029] The annular damping plate 2, radial damping plate 3, pile foundation 4 and lifting lug 7 of the present invention are welded to the anti-scour protection cover 1, and the material of the whole device is corrosion-resistant steel to extend its life on the seabed. The whole device can be prefabricated on land, and the submarine cables of similar sizes can use the same specification of the device of the present invention when the crossing angle is consistent. The device of the present invention can be recycled, easy to install and disassemble, green and environmentally friendly, highly corrosion-resistant, and low cost.

[0030] The present invention also provides an anti-scouring method using the above anti-scouring device for crossing submarine cables, comprising the following steps:

[0031] S1, determine the position of the intersection of the submarine pipe and cable: use a crane to hook the lifting lug 7 and lower the device of the present invention to the intersection of the submarine pipe and cable;

[0032] S2, adjusting the direction of the device: the diver adjusts the direction of the device underwater so that the position of the pipeline perforation 5 is just stuck above the cross pipe cable;

[0033] S3, pile insertion and stabilization: Use mud blowing equipment to blow mud in a small area at the pile foundation position. After the pile foundation 4 is inserted into the seabed, the entire device is leveled, and finally backfill is performed at the pile foundation position to stabilize the device;

[0034] S4, removal: if the pile foundation 4 is shallowly embedded in the mud, the device can be directly lifted by hooking the lifting lug 7 with a crane; if the pile foundation is deeply embedded in the mud, it is necessary to use a mud blowing device to first blow the pile foundation 4 to expose it, and then use a crane to hook the lifting lug 7 to lift the device;

[0035] S5, anti-scouring: when the incoming flow passes through the device of the present invention, the silt will be blocked by the anti-scouring device and accumulate, thus reducing the risk of scouring;

[0036] S5-1, the anti-scouring protective cover 1 can prevent the silt scouring under the submarine cable at the crossing point from causing suspension;

[0037] S5-2, the annular flow suppressor plate 2 and the radial flow suppressor plate 3 can block and slow down the bottom currents in all directions, thereby reducing the scouring effect of the bottom current on the sediment around the cables and pipes, and increasing the sedimentation effect of the sediment carried by the current, thereby preventing the formation of overhangs under the cables and pipes around the crossing points of the submarine cables and pipes.

[0038] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineering technicians in the field should fall within the protection scope of the present invention. The technical contents for which protection is sought in the present invention have been fully recorded in the technical requirements.

Claims

1. An anti-scouring device for crossing submarine cables, characterized in that: The invention comprises an anti-scour protection cover (1), wherein a plurality of pile foundations (4) are connected to the bottom surface of the anti-scour protection cover (1); a plurality of rows of flow suppression plates are evenly distributed radially on the surface of the anti-scour protection cover (1), wherein the flow suppression plates are composed of an annular flow suppression plate (2) and a radial flow suppression plate (3) connected vertically; and a plurality of pipeline through-holes (5) are symmetrically formed on the edge of the anti-scour protection cover (1).

2. The anti-scouring device for crossing submarine cables according to claim 1 is characterized in that: The anti-scour protection cover (1) is a spherical arc surface structure.

3. The anti-scouring device for crossing submarine cables according to claim 1 is characterized in that: The surface of the anti-scour protection cover (1) is provided with 8 rows of flow suppression plates, and the angle between each two adjacent rows of flow suppression plates is 45°.

4. The anti-scouring device for crossing submarine cables according to claim 1 is characterized in that: The annular flow suppression plate (2) and the radial flow suppression plate (3) have the same height.

5. The anti-scouring device for crossing submarine cables according to claim 1 is characterized in that: The pile foundation (4) is a cylindrical structure, with four piles in total, evenly distributed in the gaps between the rows of flow suppression plates.

6. The anti-scouring device for crossing submarine cables according to claim 1, characterized in that: A raised lifting lug (7) is provided directly above the anti-scour protection cover (1).

7. An anti-scouring method using the anti-scouring device for crossing submarine cables according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Determine the location of the intersection of the submarine pipe and cable, use a crane to hook the lifting lug (7), and lower the anti-scour device to the intersection of the submarine pipe and cable; S2. Adjust the direction of the anti-scour device underwater so that the position of the pipe perforation (5) is just stuck above the cross-cable; S3. Pile insertion and stabilization: Use mud blowing equipment to blow mud in a small area at the pile foundation location. After the pile foundation (4) is inserted into the seabed (8), the entire device is leveled, and finally backfill is performed at the pile foundation location to stabilize the device.

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