Protective device

Abstract

To provide a protection device capable of exhibiting a sufficient buffer effect against a collision of a vessel or the like against a float structure.SOLUTION: A protection device 3 comprises: a panel body 4 added to an outer surface of a float structure; and a float 5 fixed to a lower part of the panel body 4. The panel body 4 is formed by laying a first layer 41 composed of a foam resin or a rubber first plate material 43 and a second layer 42 composed of a fiber-reinforced concrete second plate material 44 in the above-mentioned order from the float structure side. A protruding height from the water surface of the panel body 4 can be adjusted by changing an air quantity in a float 5.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a protective device for a floating structure.

Background Art

[0002] For the purpose of reducing the emissions of greenhouse gases, the demand for renewable energy is increasing. Renewable energy includes, for example, solar power generation, wind power generation, hydroelectric power generation, geothermal power generation, biomass, etc. Wind power generation facilities may have an impact on the living environment due to the noise and vibration caused by wind turbines, and it is necessary to fully consider the impact on living spaces and the like. Therefore, they are often installed in mountainous areas away from residential areas. However, it is difficult to secure land for installing large wind turbines in mountainous areas, and it is also difficult to secure a transportation route to the wind power generation facility and install transmission lines, etc. Therefore, it has been considered to install wind power generation facilities on the sea (water). When constructing a structure on water, a floating structure may be adopted as the foundation structure (see, for example, Patent Document 1). However, there is a risk that ships and drifting objects may collide with the structure on water. In addition, although it is common for a floating structure to be moored at a predetermined position after being towed, there is also a risk that the towing vessel may come into contact during towing. If a floating structure is damaged due to a collision with a ship or a drifting object, etc., there is a risk of sinking. On the other hand, if the strength of the floating structure itself is increased to ensure impact resistance when a ship or the like collides, the floating structure becomes large-scale and uneconomical. Therefore, it may be possible to improve impact resistance by installing a protective device on the floating structure. As such a protective device, for example, Patent Document 2 discloses a structure in which a plurality of floating fenders connected at predetermined intervals are provided slidably in the vertical direction along the surface of a structure on water. However, when a pointed part such as the bow of a ship or a drifting object collides with the protective device of Patent Document 2, the floating fender may move and a gap may be generated, and there is a risk that a sufficient buffering effect cannot be obtained.

Prior Art Documents

Patent Documents

[0003] Patent Document 1 Japanese Patent Application Laid-Open No. 2018-039474 Patent Document 2 Japanese Utility Model Application Laid-Open No. 02-112719 Summary of the Invention Problems to be Solved by the Invention

[0004] An object of the present invention is to propose a protection device capable of obtaining a sufficient buffering effect against a collision of a ship or the like with a floating structure. Means for Solving the Problems

[0005] The present invention for solving the above problems is a protection device including a panel body attached to the outer surface of a floating structure and a floating body fixed to the lower part of the panel body. The panel body is formed by laminating, in order from the floating structure side, a first layer made of a first plate material made of foamed resin or rubber and a second layer made of a second plate material made of fiber-reinforced concrete. By changing the amount of air inside the floating body, the protruding height of the panel body from the water surface can be adjusted. According to such a protection device, since a panel body having a first plate material made of foamed resin or rubber is attached to the outer surface of the floating structure, the impact force at the time of a collision of a ship or the like can be absorbed, and damage to the floating structure can be reduced. Further, even when a ship or the like collides, no gap is formed in the panel body. Further, since a second plate material made of fiber-reinforced concrete is disposed on the surface of the panel body, the impact force can be dispersed and transmitted to the first plate material, and the impact force can be efficiently absorbed.

[0006] In addition, if a plurality of the second plate materials are arranged in a staggered pattern so as to cover the boundaries between the plurality of the first plate materials arranged with their end faces abutting against each other, it is possible to prevent the joint portion between the plate materials from becoming a weak portion, and the same buffering effect can be expected regardless of the position on the panel body where a ship or the like collides. It is desirable that the protection device be provided with a mooring fixture for connecting the panel body and the floating structure so that the assumed collision range can always be protected even when the draft of the floating structure fluctuates. Such a mooring fixture preferably includes a rail fixed to the floating structure, a roller that moves up and down along the rail, and a mooring cable that connects the roller and the panel body. In addition, when the floating structure includes a columnar center column disposed at the center, a plurality of side columns disposed at intervals around the center column, and an arm that connects the center column and the side columns, the panel body may be attached to the outer surface of the side column.

Advantages of the Invention

[0007] According to the protection device of the present invention, a sufficient buffering effect can be obtained against a collision of a ship or the like against the floating structure.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0009] In this embodiment, a protective device 3 for protecting the foundation structure 2 of an offshore wind power generation facility (offshore facility) 1 will be described. FIG. 1 is a perspective view of the offshore wind power generation facility 1. As shown in FIG. 1, the offshore wind power generation facility 1 has a windmill 11 and a support column 12 that supports the windmill 11, and is provided at a position higher than the water surface via the foundation structure 2. The windmill 11 is rotatably provided at the upper end of the support column 12. The support column 12 is erected on the foundation structure 2. The foundation structure 2 is a concrete floating structure. The foundation structure 2 of this embodiment includes a columnar center column 21 disposed at the center and supporting the support column 12, and a plurality (three in this embodiment) of side columns 22, 22, 22 disposed at intervals around the center column 21, and an arm 23 that connects the center column 21 and the side column 22. A protective device 3 is attached to the outer surface of the side column 22 of the foundation structure 2.

[0010] FIG. 2 shows the protective device 3. As shown in FIGS. 2(a) and (b), the protective device 3 includes a panel body 4 attached to the outer surface of the foundation structure 2 (side column 22), a floating body 5 fixed to the lower part of the panel body 4, and a mooring fixture 6 that connects the panel body 4 and the side column 22. In this embodiment, the protective device 3 is installed so as to cover a range (collision assumption range) where collision of a collision object M such as a ship or a drifting object is expected among the outer surfaces of the side columns 22.

[0011] FIG. 3 shows the panel body 4. The panel body 4 is formed by laminating a first layer 41 and a second layer 42 in order from the foundation structure 2 (side column 22) side. As shown in FIG. 3, in the first layer 41, a plurality of first plate members 43, 43,... made of foamed resin or rubber are arranged with their end faces abutting against each other. The exposed surface of the first layer 41 (for example, the surface of the first layer 41 on the foundation structure 2 side, the upper end surface or the lower end surface of the first layer 41, etc.) is covered with a deterioration prevention material (not shown). For the deterioration prevention material, for example, a polyurea resin may be used. In the second layer 42, a plurality of second plate members 44, 44,... made of fiber-reinforced concrete are arranged in a staggered pattern with their end faces butted against each other so as to cover the boundary (butt joint) between the first plate members 43. The panel body 4 is attached to the outer surface of the side column 22 in a curved state according to the shape of the side column 22 (see Fig. 2(a)). As a method of curving the panel body 4, for example, the first plate member 43 and the second plate member 44 may be formed in a shape that is pre-curved according to the shape of the side column 22, or the first plate member 43 and the second plate member 44 may be in a flat plate shape, and an angle may be provided at the joints between adjacent first plate members 43 and second plate members 44 to curve the panel body 4 according to the shape of the side column 22.

[0012] The floating body 5 is composed of a hollow member capable of storing air inside. The floating body 5 has a buoyancy that can project the panel body 4 from the water surface, and by changing the amount of air inside the floating body 5, the protruding height of the panel body 4 from the water surface can be adjusted. Fig. 4 shows the mooring fixture 6. The mooring fixture 6 includes a rail 61 fixed to the outer surface of the foundation structure 2 (side column 22), a roller 62 that moves up and down along the rail 61, and a mooring cable 63 that connects the roller 62 and the panel body 4. Since the roller 62 of the mooring fixture 6 moves up and down along the rail 61, the panel body 4 is connected to the side column 22 without preventing the up and down movement (floating and sinking) of the panel body 4. A rope, chain, wire, etc. is used for the mooring cable 63.

[0013] According to the protection device 3 of the present embodiment, even when the collision object M collides, since the first plate member 43 made of foamed resin or rubber absorbs the collision force, damage to the foundation structure 2 (floating structure) can be reduced. In addition, since the second plate member 44 made of fiber-reinforced concrete is disposed on the surface of the panel body 4, the collision force can be dispersed and transmitted to the first plate member 43, and the collision force can be efficiently absorbed. Furthermore, since the second plates 44 of the second layer 42 are arranged in a staggered pattern so as to cover the boundaries between the first plates 43 of the first layer 41, the joints between the first plates 43 or the joints between the second plates 44 are less likely to become weak points. Therefore, no gap is formed in the protective device 3 (panel body 4) regardless of where the collision object M collides, and a similar buffering effect can be expected. Since the surface (exposed surface) of the first plate 43 is covered with a deterioration prevention material (polyurethane resin), durability against deterioration caused by seawater, ultraviolet rays, etc. is ensured. In addition, since the protruding height of the panel body 4 from the water surface can be adjusted by the floating body 5, the collision assumption range can always be protected even if the draft of the foundation structure 2 fluctuates. Also, since the mooring fixture 6 connects the foundation structure 2 and the panel body 4 without hindering the vertical movement of the panel body 4, the collision assumption range can always be protected even if the draft of the foundation structure 2 fluctuates.

[0014] The analysis results verifying the effects of the protective device 3 of the present embodiment are shown below. In the analysis, it was assumed that a towed ship (collision object M) with a displacement of 200 tons collided at a collision speed of 5 knots (≈2.6 m / s) at the center of a reinforced concrete slab 20 with a length of 5000 mm, a width of 5000 mm, and a thickness of 500 mm as the foundation structure 2 (see Fig. 5). Fig. 5 is a perspective view showing the analysis model. The concrete constituting the reinforced concrete slab 20 has a design standard strength of FC50 N / mm 2 and the reinforcing bars are D51, with two layers of longitudinal and transverse reinforcement arranged at a pitch of 200 mm.

[0015] As the panel body 4 (protective device 3) installed on the surface of the foundation structure 2 (reinforced concrete slab 20), in Example 1, the first plate 43 was a plate made of polystyrene foam (EPS) with a thickness of 450 mm, and the second plate 44 was a plate made of ultra-high-strength fiber-reinforced concrete (UFC) with a thickness of 50 mm (see Fig. 5(b)). In Example 2, the first plate 43 was a rubber plate (lattice or honeycomb shape) with a thickness of 300 mm, and the second plate 44 was a plate made of ultra-high-strength fiber-reinforced concrete (UFC) with the same thickness of 50 mm as in Example 1 (see Fig. 5(c)). Further, as a comparative example, as shown in Fig. 5(a), analysis was also performed on the reinforced concrete slab 20 without the protective device 3 installed.

[0016] In Comparative Example 1 without the protective device 3 installed, the reinforced concrete slab 20 was severely damaged. Also, in Comparative Example 1, the reinforcing bars yielded. On the other hand, in Examples 1 and 2 where the protective device 3 was installed, the damage to the reinforced concrete slab 20 was minor. It was confirmed that the impact load could be buffered in both cases, i.e., when using a foamed resin as the first plate material 43 (Example 1) and when using a rubber plate (Example 2). Also, the stress of the reinforcing bars in Examples 1 and 2 was within the elastic range. As described above, it was confirmed that according to the protective device 3 of the present embodiment, a buffering effect against the collision of ships and floating objects with the floating structure can be obtained.

[0017] Although the embodiments of the present invention have been described above, the present invention is not limited to the foregoing embodiments, and each of the above-described components can be appropriately changed without departing from the spirit of the present invention. In the above embodiment, the case where the foundation structure 2 has a so-called semi-submersible type having a center column 21 and side columns 22 has been described. However, the form of the foundation structure 2 is not limited, and for example, it may be a barge type, a spar type, or a TLP type. Also, the floating structure protected by the protective device 3 is not limited to the foundation structure 2 of the offshore wind power generation facility 1. Also, the water facility is not limited to the offshore wind power generation facility 1.

[0018] In the above embodiment, the protective device 3 was installed for the assumed collision range of the side column 22. However, as shown in Figs. 6(a) and (b), the protective device 3 may be installed so as to surround the entire circumference of the side column 22 or the entire circumference of the foundation structure 2. The configuration of the mooring jig 6 is not limited. For example, if the end of the mooring cable 63 is slidable along the rail 61, the roller 62 may be omitted. Further, the mooring jig 6 may be installed as necessary. The first plate member 43 and the second plate member 44 do not necessarily have to be arranged in a staggered pattern, and the arrangement, number, etc. of the first plate member 43 and the second plate member 44 are not limited. When using a rubber plate as the first plate member 43, the rubber plate may be a solid plate material, or may be in a honeycomb shape or a lattice shape.

Explanation of Reference Numerals

[0019] 1 Offshore wind power generation facility (offshore facility) 2 Foundation structure (floating structure) 21 Center column 22 Side column 23 Arm 3 Protective device 4 Panel body 41 First layer 42 Second layer 43 First plate member 44 Second plate member 5 Floating body 6 Mooring jig 61 Rail 62 Roller 63 Mooring cable

Claims

1. A protective device comprising a panel body attached to the outer surface of a floating structure and a floating body fixed to the lower part of the panel body, wherein the panel body is formed by laminating, in order from the floating structure side, a first layer made of a first plate material made of foamed resin or rubber and a second layer made of a second plate material made of fiber-reinforced concrete, and the protruding height of the panel body from the water surface can be adjusted by changing the amount of air inside the floating body. The protective device is characterized by this.

2. In the first layer, a plurality of the first plate materials are arranged, In the second layer, a plurality of the second plate materials are arranged in a staggered pattern so as to cover the boundaries between the first plate materials. The protective device according to claim 1 is characterized by this.

3. It is provided with a mooring fixture for connecting the panel body and the floating structure, The mooring fixture, A rail fixed to the floating structure, A roller that moves up and down along the rail, And a mooring cable connecting the roller and the panel body. The protective device according to claim 1 or claim 2 is characterized by this.

4. The floating structure includes a columnar center column disposed at the center, a plurality of side columns disposed at intervals around the center column, and an arm connecting the center column and the side columns, The panel body is attached to the outer surface of the side column. The protective device according to any one of claims 1 to 3 is characterized by this.

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