CN212480524U

CN212480524U - Ballast protection pad

Info

Publication number: CN212480524U
Application number: CN202020851101.0U
Authority: CN
Inventors: 王珏; 许福丁; 章泽; 张明杰; 张柏英
Original assignee: Maccaferri Changsha Enviro Tech Co ltd
Current assignee: Maccaferri Changsha Enviro Tech Co ltd
Priority date: 2020-05-20
Filing date: 2020-05-20
Publication date: 2021-02-05
Anticipated expiration: 2030-05-20

Abstract

The utility model discloses a ballast protection pad, which is characterized in that the ballast protection pad comprises a wrapping layer (1), a net cage (2) and a filler (3), wherein the filler (3) is filled in the net cage (2), and the net cage (2) and the filler (3) are both wrapped by the wrapping layer (1); the filler (3) comprises bitumen and/or asphalt mix. The ballast protection pad of the utility model has the advantages that the counterweight can greatly improve the hydraulic stability of the submarine pipeline, and ensure the stability of the submarine pipeline under the action of waves and ocean currents; the structure has good flexibility and integrity, can adapt to the change of pipelines and submarine topography, and simultaneously, the good hydrodynamic appearance of the surface of the protection pad can avoid the secondary scouring of the seabed around the pipelines; good impact resistance is able to withstand impacts from above the pipeline very well.

Description

Ballast protection pad

Technical Field

The utility model relates to a ballast protection pad belongs to seabed (underwater) pipeline protection technical field.

Background

With the exploitation of a large amount of offshore oil, the development and the use of engineering technologies such as offshore drilling platforms, submarine pipelines and the like are rapidly developed. A submarine pipeline, i.e., a pipeline system laid on the seabed for transporting offshore oil and gas, is an essential important component of an energy production system, called an "offshore lifeline", which is a main transmission mode in offshore oil and gas development and is widely used in marine engineering.

The ocean environment where the submarine pipeline is located is generally very severe, and under the coupling action of waves and currents, sediment at the bottom bed of the pipeline is easy to corrode and transport, so that the pipeline is suspended and unbalanced, and the pipeline is damaged. The pipeline accident is mainly caused by that the flow field and the pressure field around the pipeline change, so that the local scouring of the seabed below is caused, the pipeline is suspended and generates vibration under the hydrodynamic force to cause the fracture of the pipeline. In the initial stage of pipeline construction, a mechanical means is generally adopted to dig a pipe trench on a seabed and artificially bury a pipeline in the seabed so as to reduce the influence of waves or ocean currents on the pipeline. However, due to the complexity of the marine environment in which the pipeline is located, the risk of the pipeline being exposed to the sea bed in response to waves, currents, damage to the sea bed, and third party damage (such as anchor dropping, drag anchors, or other falling objects) remains.

In summary, subsea pipelines face three major categories of problems: firstly, elutriating; secondly, the problem of self stability; and thirdly, destroying by a third party. These three types of problems often do not occur individually, but rather overlap with each other. For example, panning may reduce the coverage of the pipeline, allow an unstable condition in an original stable pipeline due to a reduction in upper ballast, and allow the pipeline to be more vulnerable to third party damage due to a lack of upper ballast protection. The main solutions and disadvantages of the three problems are described below.

The main treatment modes for the elutriated pipeline at present are as follows:

1) and the back of the sea pipe in the non-stop state is trenched, so that the pipeline work is not influenced, and the exposed pipeline is buried into the seabed again and needs to be supported by large-scale equipment.

2) The bionic aquatic weeds are planted in areas with serious scouring, and the bionic aquatic weeds float under the action of buoyancy, so that the flow speed is reduced and silt deposition is accelerated. The bionic aquatic weed fixing device has the advantages of slow effect, high fixing difficulty of the bionic aquatic weed, consideration of influence on ships in sea areas with requirements on the ships, and unsuitability for areas with shallow water depth.

3) The flow blocking plate is added to enable the pipeline to sink automatically, and the principle is the same as that of the bionic grass; slow onset of action, need to be fixed on the pipe.

4) Reclamation of sea sand or burial with other ballast. The effect is not good, even if the original pipeline is buried, the scouring may occur again, and the pipeline buried again is easily exposed by the scouring again.

The main treatment mode for the pipeline with the self-stability problem is as follows:

1) and fixing the chain row by using a concrete pressing block. The disadvantages are that the joint is a weak point and the laying stability is poor.

2) And anchoring the pipeline. The disadvantage is that the construction difficulty is large.

3) And adding a pipeline counterweight. The method is determined to be basically not adopted for the operated pipeline, and the cost and the difficulty are high.

The main current treatment methods for preventing third party damage are as follows:

1) and burying the pipeline. The burial depth is generally adopted to prevent the third party from damaging, and the burial depth required by the third party is very deep, generally more than 2m, and the cost is relatively high.

2) And fixing the chain row by using a concrete pressing block. The disadvantages are poor energy absorption, poor structural durability and several weak points of protection.

In summary, the current solutions can only solve a single problem basically, and the solutions to the composite problem are basically the superposition of solutions or the simple combination of materials, such as the combination of interlocking blocks and bionic aquatic weed, for solving the corresponding problem. Firstly different materials and solutions have their own disadvantages, secondly the combination of different materials is critical for the integrity of the materials, and secondly materials and solutions cannot be combined correspondingly due to their uniqueness. Such combinations have a general disadvantage in that the integrity of the material is not strong.

SUMMERY OF THE UTILITY MODEL

In order to effectively deal with the destruction of elutriation and third party, for seabed (underwater) pipeline provides the long-term protection reliably, the utility model provides a ballast protection pad, concrete technical scheme as follows.

The ballast protection pad is characterized by comprising a wrapping layer, a net cage and fillers, wherein the filler is filled in the net cage, and the net cage and the filler are both wrapped by the wrapping layer; the filler comprises bitumen and/or asphalt mix.

By adopting the ballast protection pad, the net cage roughly determines the distribution space of the filler, determines the overall shape of the ballast protection pad, plays roles of fixing and framing, has certain flexibility, and the filler also has certain flexibility, so that the whole ballast protection pad has certain flexibility, and the wrapping layer is used for preventing the loss of the filler. When the ballast protection pad covers the underwater pipeline, the ballast protection pad is bent to a certain degree, and the ballast protection pad is arched. At the same time, the ballast protection pad has a greater weight and is able to provide ballast protection against elutriation. When the ballast protection pad suffers from the external impact of a third party, external force can be diffused to the whole ballast protection pad, so that the external force is dispersed to protect the pipeline.

Further, the wrapping layer is made of geotextile. Preferably, polypropylene geotextile, geotextile are as a traditional anti-filter material, and fine particles that prevent that can be fine move outward, and the ballast protection pad is pressed and is protected on the seabed at pipeline place, can also prevent to press and protect fine particles under the seabed and permeate through the parcel layer migration to reach the effect of anti-straining and scour prevention. And the effect is fast, and the ballast protection pad can achieve the anti-filtration and anti-scouring effects after being laid and installed.

Further, the net cage is hexahedron, and adopts steel wire net or polymer net. Preferably, the steel wire mesh is a steel wire mesh with double-twisted hexagonal meshes. The net cage plays the role of fixing and framing, has certain deformability, can be well adapted to various underwater stress states, and enables the structure of the ballast protection pad not to be damaged in the manufacturing, hoisting and using processes.

Further, the filler adopts asphalt mixture. The asphalt mixture is a conventional material and widely applied to expressways, and is a composite material mainly comprising asphalt, coarse aggregate, fine aggregate and mineral powder, and polymer and wood cellulose are added into the asphalt mixture. The asphalt mixture has good flexibility, and can be self-healed even if cracks appear, so that the ballast protective pad has excellent deformability, adaptability and stability.

Further, the top surface of the net cage is wrapped in the asphalt mixture. The asphalt mixture is poured to fill the inside of the net cage and is higher than the top surface of the net cage by a certain distance, so that the bonding strength of the asphalt mixture and the top surface of the net cage can be enhanced, the top surface of the net cage is prevented from being damaged in the using process, and the integrity and the stability of the whole ballast protection pad are improved. The asphalt mixture is wrapped in the wrapping layer, so that the asphalt mixture outside the net cage can not be lost.

Furthermore, the filler comprises a two-layer structure, wherein the lower layer is a stone layer, and the upper layer is an asphalt layer. The stone layer can ensure the whole weight of the ballast protection pad and can not influence the bending deformation of the ballast protection pad when the ballast protection pad is covered on the pipeline; the cost can be greatly reduced by adopting the stone layer.

Further, the top surface of the net cage is wrapped in the asphalt layer. The connection of pitch layer and box with a net top surface is comparatively firm like this, prevents that the box with a net top surface from taking place to destroy in the use, and the combination of pitch layer and parcel layer also can be very inseparable moreover, is favorable to promoting the wholeness and the stability that the ballast protected to fill up.

Furthermore, the ballast protection pad further comprises a plurality of hoisting structures, each hoisting structure comprises an anchor backing plate and a hoisting piece which are fixedly connected with each other, the anchor backing plate is located between the bottom surface of the net cage and the wrapping layer below the bottom surface, and the hoisting pieces penetrate through the top surface of the net cage and the wrapping layer above the top surface. The anchor backing plate is contacted with the net cage and the filling layer surface, so that the lifting force is dispersed, and the smooth operation of the lifting operation can be ensured.

Furthermore, the hoisting piece comprises a cylindrical barrel and a hoisting rope, the cylindrical barrel is fixedly connected with the anchor backing plate, the hoisting rope is fixedly connected with the cylindrical barrel, and the hoisting rope penetrates through the top surface of the net cage and the wrapping layer above the top surface.

Further, the hoisting part comprises an inverted U-shaped steel bar and a hoisting rope, the inverted U-shaped steel bar is fixedly connected with the anchor backing plate, the hoisting rope is fixedly connected with the inverted U-shaped steel bar, and the hoisting rope penetrates through the top surface of the net cage and the wrapping layer above the top surface.

Further, the density of the ballast protection pad is not less than 1.8t/m for cultivation. So as to achieve the effect of stable ground loading.

Further, the maximum bending angle of the ballast protection pad is not less than 120 ℃ in a temperature environment of 0-5 ℃.

The ballast protection pad of the utility model has the advantages that the counterweight can greatly improve the hydraulic stability of the submarine pipeline, and ensure the stability of the submarine pipeline under the action of waves and ocean currents; the structure has good flexibility and integrity, can adapt to the change of pipelines and submarine topography, and simultaneously, the good hydrodynamic appearance of the surface of the protection pad can avoid the secondary scouring of the seabed around the pipelines; the good impact resistance can well resist the impact from the upper part of the pipeline; the physical and chemical properties can adapt to unique environments such as seawater and the like, the structural durability is ensured, and the environmental protection performance of the structure meets the requirements.

The utility model discloses a ballast protection pad all has better effect to the condition (elutriation, pipeline self stability, third party destruction) of three kinds of submarine pipeline protection.

The elutriation often is because the velocity of flow of rivers is greater than the starting velocity of flow of base material and has caused the migration of base material, and outside parcel layer comprises geotechnological cloth, as a traditional anti-filter material, can be fine prevent the outward migration of fine particle, so flexible ballast protection pad is protecting on the seabed at pipeline place pressing, can prevent to press and protect the fine particle under the seabed and permeate the protection pad migration to reach the effect of anti-filtering and scour prevention. And the effect is fast, lay the installation and finish and can reach the anti-scour effect of straining.

The net cage and the filler are flexible filling materials, and the filling materials have higher density, can provide good ballast effect and maintain the stability of the pipeline; the flexible pipe can still keep flexibility in the low-temperature environment (0-5 ℃) of the ocean, can well adapt to the appearance of the pipeline and is attached to the pipeline; meanwhile, the flexible ballast protection pad can well adapt to the topography of the seabed, and can be better attached to an elutriation part when elutriation occurs at the edge of the flexible ballast protection pad, so that further expansion of elutriation is prevented. Meanwhile, the protection pad is a whole body (different from a chain row isodisperse body structure), and under the condition of external impact of a third party, external force can be diffused to the whole protection pad, so that the external force is dispersed to protect the pipeline. The hoisting structure ensures that the flexible ballast protection pad can meet the functions through simple hoisting, the construction machinery is simple, the construction efficiency is high, the pipeline is not required to be stopped for production and matched for construction, and the later-stage maintenance of the pipeline is also very convenient.

Drawings

Figure 1 is a schematic view of a ballast protection pad according to example 1 of the present invention;

figure 2 is a schematic view of the ballast protection pad of example 1 of the present invention covering a pipeline;

figure 3 is a schematic view of the ballast protection pad of example 1 of the present invention covering a pipeline;

FIG. 4 is a schematic cross-sectional view of the ballast guard mat of example 1 (hoisting structure not shown);

FIG. 5 is a schematic view of a lifting structure;

FIG. 6 is another schematic view of the lifting structure;

fig. 7 is a schematic cross-sectional view of the ballast guard mat of example 2 (hoisting structure not shown).

In the figure: the steel wire rope comprises a wrapping layer 1, a net cage 2, a filler 3, a stone layer 3.1, an asphalt layer 3.2, a hoisting structure 4, an anchor backing plate 4.1, a cylindrical barrel 4.2, a hoisting rope 4.3 and an inverted U-shaped steel bar 4.4.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example 1

Referring to fig. 1-4, the ballast protection pad comprises a wrapping layer 1, a net cage 2 and a filler 3, wherein the net cage 2 is filled with the filler 3, and the net cage 2 and the filler 3 are both wrapped by the wrapping layer 1; the filler 3 is asphalt mixture.

Preferably, the top surface of the net cage 2 is wrapped in a filler 3.

The wrapping layer 1 is made of geotextile. The wrapping layer 1 provides external wrapping and reverse filtration functions, and the geotextile can be divided into woven and non-woven by a manufacturing process. The material types are also various polypropylene fibers, terylene, chinlon, vinylon, polyethylene and the like. The polypropylene geotextile is preferably selected, the melting point of the polypropylene geotextile is similar to the temperature of the asphalt mixture during pouring, so that the geotextile can be better attached, and the integrity of the product is better.

The net cage 2 is used for forming a structural cavity, the net cage 2 is preferably a flat hexahedron, the hexahedron is preferably a cuboid or a cube with a smaller height, a steel wire mesh or other flexible net surfaces (such as a polymer net surface) are adopted, the physical and mechanical properties of the net cage can play a role of a flexible framework, and the structure of the protection pad cannot be damaged in the manufacturing, hoisting and using processes. It should be noted that: the net cage 2 can be a steel wire mesh with double-twisted hexagonal meshes, and can also be a net cage structure in other forms, for example, the net cage body is made of the steel wire mesh, and the net cage cover is made of glass fiber grids and the like.

The filler 3 is an asphalt mixture which is a conventional material and widely applied to expressways, and the asphalt mixture is a composite material mainly comprising asphalt, coarse aggregate, fine aggregate and mineral powder, and polymer and wood cellulose are added. The asphalt mixture has better flexibility, and can be self-healed even if cracks appear, so that the ballast protective pad has excellent deformation capacity, adaptability and stability; meanwhile, the asphalt mixture is friendly to water environment, and the release amount of pollutants is within the specified limit value.

Preferably, the ballast protection pad further comprises a hoisting structure 4. In one embodiment, as shown in fig. 5, the hoisting structure 4 comprises an anchor backing plate 4.1 and a hoisting member fixedly connected with each other, the hoisting member comprises a cylindrical barrel 4.2 and a hoisting rope 4.3, the cylindrical barrel 4.2 is fixedly connected with the anchor backing plate 4.1, the hoisting rope 4.3 is fixedly connected with the cylindrical barrel 4.2, and the hoisting rope 4.3 penetrates through the top surface of the net cage 2 and the wrapping layer 1 above the top surface. A through hole is formed in the cylindrical barrel 4.2, and the lifting rope 4.3 can penetrate through the through hole; or a bolt is fixed in the through hole, and the lifting rope 4.3 is fixed on the bolt. It should be noted that the lifting structure may be eliminated and other means (e.g., binding) may be used to lift the ballast protection pads.

In one embodiment of the hoisting structure, as shown in fig. 6, the hoisting structure 4 comprises an anchor backing plate 4.1 and a hoisting member fixedly connected with each other, the hoisting member comprises an inverted U-shaped steel bar 4.4 and a hoisting rope (not shown), the inverted U-shaped steel bar 4.4 is fixedly connected with the anchor backing plate 4.1, the hoisting rope is fixedly connected with the inverted U-shaped steel bar 4.4, and the hoisting rope penetrates through the top surface of the net cage 2 and the wrapping layer 1 above the top surface. The hoisting structure 4 can ensure the smooth hoisting operation without large deformation in the hoisting process.

In the above solution, the top surface of the net cage 2 is wrapped in the filler 3, but it can be understood by those skilled in the art that the top surface of the net cage 2 may not be wrapped by the filler 3.

The utility model discloses a ballast protection is filled up preferably will have following effect and performance requirement:

1) carrying out thin-wall high-speed dry-rolling and high-speed dry-rolling on the flexible ballast protection cushion to obtain a stable ground load effect;

2) the ballast protection pad has the maximum bending angle of not less than 120 degrees at the temperature of 0-5 ℃, and can be well covered on a protection pipeline;

3) the flexible ballast protection pad should resist the impact of a submarine falling object (such as an anchor or other heavy objects) without being damaged, and the anti-impact protection energy level is not less than 17 kJ;

4) the flexible ballast protection pad should be able to withstand a certain load without significant deformation and damage. The performance is as follows: after the load of 9t acts for 90 days, the deformation is controlled within a controllable range;

5) the release amount of pollutants (such as PAHs, heavy metals, hydrocarbons and the like) of the flexible ballast protection pad in water does not exceed the limit value specified by environmental protection;

6) the physical and chemical properties can adapt to the unique engineering environment, and the structural durability is ensured.

Example 2

Referring to fig. 7, in the case of the same structure as that of embodiment 1, embodiment 2 is different from embodiment 1 in that: the filler 3 in embodiment 2 comprises a two-layer structure, the lower layer is a stone layer 3.1, the upper layer is an asphalt layer 3.2, and the top surface of the net cage 2 is wrapped in the asphalt layer 3.2. The stone layer can ensure the whole weight of the ballast protection pad and can not influence the bending deformation of the ballast protection pad when the ballast protection pad is covered on the pipeline; the cost can be greatly reduced by adopting the stone layer. The connection of pitch layer and box with a net top surface is comparatively firm, is favorable to preventing that the box with a net top surface from taking place to destroy in the use, and the combination of pitch layer and parcel layer also can be very inseparable moreover, is favorable to promoting the wholeness and the stability that the ballast protected to fill up. It should be noted that: the asphalt layer 3.2 can also be made of asphalt mixture.

The embodiments of the present invention have been described above with reference to the accompanying drawings, and features of the embodiments and examples of the present invention may be combined with each other without conflict. The present invention is not limited to the above-mentioned embodiments, which are only illustrative and not restrictive, and those skilled in the art can make many forms without departing from the spirit and the scope of the present invention, which is encompassed by the present invention.

Claims

1. The ballast protection pad is characterized by comprising a wrapping layer (1), a net cage (2) and a filler (3), wherein the filler (3) is filled in the net cage (2), and the net cage (2) and the filler (3) are wrapped by the wrapping layer (1); the filler (3) comprises bitumen or bituminous mixture, or the filler (3) comprises a layer of bitumen and a layer of bituminous mixture.

2. The ballast protective pad according to claim 1, wherein the wrapping layer (1) is made of geotextile.

3. The ballast protection pad according to claim 1, wherein the net cage (2) is hexahedral and is made of steel wire mesh or polymer mesh.

4. The ballasted protective mat of claim 3, wherein the steel mesh is a twisted hexagonal mesh steel mesh.

5. The ballast protective mat according to claim 1, wherein the filler (3) is an asphalt mixture.

6. A ballast protection mat according to claim 5, wherein the top surface of said net cage (2) is wrapped in said asphalt mixture.

7. The ballast protective pad according to claim 1, wherein the filler (3) comprises a two-layer structure, the lower layer being a stone layer and the upper layer being an asphalt layer, the top surface of the net cage (2) being wrapped in the asphalt layer.

8. The ballast protection pad according to claim 1, further comprising a plurality of hoisting structures (4), wherein the hoisting structures (4) comprise anchor backing plates (4.1) and hoisting members fixedly connected to each other, the anchor backing plates (4.1) are located between the bottom surface of the net cage (2) and the wrapping layer (1) below the bottom surface, and the hoisting members pass through the top surface of the net cage (2) and the wrapping layer (1) above the top surface.

9. A ballast protection pad according to claim 8, wherein the lifting means comprises a cylindrical drum (4.2) and a lifting rope (4.3), the cylindrical drum (4.2) being fixedly connected to the anchor pad plate (4.1), the lifting rope (4.3) being fixedly connected to the cylindrical drum (4.2), the lifting rope (4.3) passing through the top surface of the net cage (2) and the wrapping layer (1) above the top surface; or the hoisting part comprises an inverted U-shaped steel bar (4.4) and a hoisting rope (4.3), the inverted U-shaped steel bar (4.4) is fixedly connected with the anchor backing plate (4.1), the hoisting rope (4.3) is fixedly connected with the inverted U-shaped steel bar (4.4), and the hoisting rope (4.3) penetrates through the top surface of the net cage (2) and the wrapping layer (1) above the top surface.

10. The ballast protection pad of claim 1, wherein the density of the ballast protection pad is not less than 1.8t/m, and the maximum bending angle of the ballast protection pad is not less than 120 ° under a temperature environment of 0-5 ℃.