JPH10244989A - Low rolling type floating body structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constantly keep a low rocking property while keeping the sufficient loadable weight with a simple structure, by forming a main floating body of octagonal pole, and setting a ratio of a width of the main floating body and a width of a submerged buoyancy structure within a specific range on all vertical sections passing through the plane center of the main floating body. SOLUTION: A floating body structure comprises a pole-shaped main floating body 2, and a flat submerged buoyancy structure 1 connected to a lower edge of the main floating body. The main floating body 2 has a shape of octagonal pole, the flat submerged buoyancy structure 1 is octagonally shaped in a plan view, and has the vertical center line same as that of the main floating body 2, and the corresponding sides of the same are in parallel with each other. Further a ratio of a width of the main floating body 2 and a width of the submerged buoyancy structure 1 is set within 1/2 through 4/5 on all vertical sections passing through the plane center of the main floating body 2. In this structure, a natural period of the rocking of the floating body structure becomes long by the mass of the water mass moved after the submerged buoyancy structure 1, so that the rocking can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-oscillation type floating structure suitable for installing plants such as power plants, oil production facilities, waste cleaning plants, hotels, recreational facilities and the like on the sea.

[0002]

2. Description of the Related Art In general, floating structures for installing plants are roughly classified into a box type (pontoon type), a semi-submersible type and a normal ship type. As the box-shaped floating structure, there are those shown in FIG. 5A (plan view) and FIG. 5B (elevated view), and the floating structure 6 having the shape of a rectangular parallelepiped is the water line 3. , And necessary facilities are arranged in the upper or inner space.

Further, a semi-submersible floating structure is shown in FIG.
As shown in FIGS. (a) (plan view) and (b) (side view), a vertical column (column) 8 having a draft line 3 at an intermediate height on a submerged floating structure (lower hull) 7. And the deck structure 4 is connected to the deck structure section 4 via the base.

Further, as shown in FIGS. 7 (a) and 7 (b), a normal hull-shaped floating structure 9 floating on the draft line 3 has a width / length that is larger than that of the box-type floating structure shown in FIG. The ratio is small, and the direction is strongly dependent on wind, water current, and wave load factors.

[0005]

One of the requirements for a floating structure for mounting a plant or the like is that it is less swayed by waves. Among the above-mentioned prior arts, the box-shaped floating structure is suitable for use in a relatively calm water area, and it is difficult to obtain a low oscillating property in a water area facing the open sea where waves of a long wavelength enter.

[0006] A semi-submersible floating structure can provide good low oscillating properties even for an incoming wave having a long wavelength and a large wave height. There is a drawback in that the weight that can be mounted thereon is limited, and that it is liable to tilt with respect to movement of the center of gravity or wind load.

Further, a floating structure having an ordinary hull form can obtain a relatively good low swaying property if the bow can always be set up in the direction of entry of the wind, water flow and waves, but the change of weather can be obtained. Since it is difficult to instantaneously follow the motion, it is not suitable for always maintaining low oscillating properties.

As described above, in the prior art, in a water area facing the open sea where a wave of a long wavelength enters, it is not possible to always secure a low oscillating property while securing a sufficient mountable weight. Therefore, an object of the present invention is to provide a low-sway type floating structure capable of always maintaining a low-sway property while securing a sufficient mountable weight with a simple structure.

[0009]

In order to solve the above-mentioned problems, a low swaying type floating structure of the present invention comprises a columnar main floating body penetrating the water surface, and a lower main body connected to a lower end of the main floating body. In a floating structure consisting of a flat submerged buoyant structure projecting outward from the outer periphery of the main floating body is formed in an octagonal column shape, and in all longitudinal sections passing through the plane center of the main floating body, The ratio of the width of the main floating body to the width of the submerged buoyancy structure is set to 1/2 to 4/5.

[0010] In the above-mentioned low-swing type floating structure of the present invention,
Since the main floating body is formed in the shape of an octagonal prism, the waterline area at the draft line will be sufficiently secured, which will provide sufficient loadable weight and stability when inclined due to wind force etc. You will be able to get enough. And since the wide peripheral wall of the main floating body is all formed by a flat plate,
The construction work is significantly simplified as compared with the case of the cylindrical shape.

Further, since a flat submerged buoyancy structure projecting outward from the outer periphery of the main floating body is provided at the lower end of the main floating body, the mass of a water mass (so-called additional water) moving following the flat buoyant structure is provided. The natural period of the vertical motion, pitching, and rolling of the floating structure is longer than that of the box-shaped floating structure and is away from the period of the entering wave, so that the fluctuation is reduced. In all longitudinal sections passing through the center of the plane of the floating body, the ratio of the width of the main floating body to the width of the submerged buoyant structure is set to 1/2 to 4/5. It is possible to easily achieve a sufficiently low oscillating property by setting the length in the entering wave entering direction to be equal to or longer than the wavelength of the entering wave by a normal design taking structural strength into consideration.

Further, when a wave breaking structure for breaking an incoming wave is mounted so as to surround the outer periphery of the main floating body, a wave load received by the floating body structure due to the incoming wave can be efficiently reduced. . Since the octagonal column-shaped main floating body has an outer peripheral surface formed by a vertical plane, there is an advantage that mounting work of the wave breaking structure becomes easier than in the case of a cylindrical surface.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 (a) and FIG. 1 (b) show a first embodiment of the present invention.
It shows a low-swaying floating structure as an embodiment,
(a) is a plan view and (b) is an elevation view.

As shown in FIGS. 1A and 1B, the floating structure has a columnar main floating body 2 penetrating a water surface 3 and a flat submerged buoyancy coupled to a lower end of the main floating body 2. The submerged buoyancy structure 1 has a shape protruding outward from the outer periphery of the main floating body 2.

The main floating body 2 is formed in an octagonal column shape.
In this embodiment, especially the flat submerged buoyancy structure 1 is also formed in an octagon when viewed in a plane, has the same vertical center axis as the octagonal column-shaped main floating body 2, and each side of the corresponding octagon is They are arranged so as to be parallel to each other.

In all vertical sections passing through the center of the plane of the main floating body 2 so that the submerged buoyant structure 1 projects sufficiently outward from the outer periphery of the lower end of the main floating body 2, the width of the main floating body 2 The ratio to the width of the water buoyancy structure 1 is set to 1/2 to 4/5.

In the low swaying type floating structure of the present embodiment, since the main floating body 2 is formed in an octagonal column shape, a sufficient water line area at the draft line can be ensured. In addition to the possible weight, it also provides sufficient stability in the event of a slope due to wind or other forces.

Further, since the octagonal column-shaped main floating body 2 is close to a rotationally symmetric body, there is also an advantage that the turning movement is suppressed. And
Since the wide peripheral wall of the main floating body 2 is entirely formed of a flat plate, the construction work is significantly simplified as compared with the case of the cylindrical shape.

At the lower end of the main floating body 2, a flat submerged buoyant structure 1 which protrudes outward from the outer periphery of the main floating body 2 is provided. Due to the mass, the natural period of the vertical motion, pitching and rolling of the floating structure is longer than that of the box-shaped floating structure, and is away from the period of the incoming wave. In the form, the ratio of the width of the main floating body 2 to the width of the submerged buoyant structure 1 is set to 1/2 to 4/5 in all longitudinal sections passing through the center of the plane of the main floating body 2, so that the submerged It is possible to easily achieve a sufficiently low oscillating property by setting the length of the buoyancy structure 1 in the direction of the approaching wave to be equal to or longer than the wavelength of the approaching wave by a normal design in consideration of the structural strength.

Since the submerged buoyant structure 1 has a flat shape, the outer shape may be circular. However, as in the present embodiment, the submerged buoyant structure 1 is also formed as an octagonal short column. This is advantageous in terms of work.

Next, a second embodiment of the present invention will be described. FIG. 2A is a plan view and FIG. 2B is an elevation view. As shown in FIGS. 2A and 2B, also in the case of the second embodiment, a columnar main floating body 2 penetrating through a water surface 3 and a flat submerged buoyancy coupled to a lower end of the main floating body 2 are provided. The submerged buoyant structure 1 has a shape that protrudes outward from the outer periphery of the main floating body 2.

The main floating body 2 is formed in an octagonal column shape.
The flat submerged buoyant body structure 1 is also formed in an octagonal shape when viewed in a plane, has the same vertical center axis as the octagonal column-shaped main floating body 2, and each side of the corresponding octagon is parallel to each other. It is arranged as follows.

In all vertical sections passing through the center of the plane of the main floating body 2, the width of the main floating body 2 and the submerged buoyant structure 1 are sufficiently extended so that the submerged buoyant structure 1 projects sufficiently outward from the outer periphery of the lower end of the main floating body 2. The ratio to the width of the water buoyancy structure 1 is set to 1/2 to 4/5.

In the second embodiment, the deck structure 4 is connected to the upper end of the main floating body 2 in particular.
Is substantially the same shape and size as the submerged buoyancy structure 1. That is, the deck structure 4 is also a flat structure having an octagonal planar shape, and the arrangement of each side is aligned with each corresponding side of the octagonal submerged buoyancy structure 1.

In the above-described second embodiment, by combining the main floating body 2 and the flat submerged buoyant structure 1, the same operation and effect as in the above-described first embodiment can be obtained. Since the deck structure portion 4 having the structure is provided, when a plant or the like is mounted, the arrangement of various facilities can be performed effectively by using not only the inside of the main floating body 2 but also the upper surface of the deck structure portion 4. There are advantages. In addition, if necessary, the deck structure 4 and the submerged buoyancy structure 1 can be reinforced by being connected with a support.

Next, a low-swing type floating structure according to a third embodiment of the present invention will be described. FIG. 3A is a plan view and FIG. 3B is an elevation view. As shown in FIGS. 3A and 3B, the low swaying floating structure of the third embodiment is the same as the low swaying floating structure of FIGS. 2A and 2B. Breaking structure 5 for breaking incoming waves around
The structure 5 is disposed so as to surround the outer periphery of the main floating body 2 as shown in FIG.

FIG. 4A shows the structure of the wave breaking structure 5.
As shown in the figure, a plurality of horizontal plates 5a are provided in a step shape,
As shown in FIG. 4 (b), a plurality of inclined plates 5b may be arranged at intervals from one another, or a perforated plate 5c may be provided as shown in FIG. 4 (c). it can.

In the third embodiment, the same operation and effect as those of the second embodiment can be obtained. In addition, a wave breaking structure 5 for breaking an incoming wave is mounted so as to surround the outer periphery of the main floating body 2. Therefore, the wave load that the floating structure receives due to the approaching wave can be efficiently reduced. Since the octagonal column-shaped main floating body 2 has an outer peripheral surface formed by a vertical plane, there is an advantage that the work of mounting the wave breaking structure 5 is easier than in the case of a cylindrical surface.

[0029]

As described in detail above, the following effects can be obtained according to the low-swaying floating structure of the present invention. (1) Since the main floating body is formed in the shape of an octagonal prism, the waterline area at the draft line can be sufficiently secured, which provides sufficient loadable weight and tilts in response to wind power etc. The stability of the case can be obtained sufficiently. (2) Since the wide peripheral wall of the main floating body is entirely formed of a flat plate, the construction work is significantly simplified as compared with the case of the cylindrical shape. (3) At the lower end of the main floating body, a flat submerged buoyant structure that protrudes outward from the outer periphery of the main floating body is provided. Since the natural periods of the vertical motion, the vertical motion, and the horizontal motion of the floating structure are longer than those of the box-shaped floating structure and are away from the period of the incoming wave, the fluctuation is reduced. (4) In all longitudinal sections passing through the center of the plane of the main floating body, the ratio of the width of the main floating body to the width of the submerged buoyant structure is 1/2 to 2
Since it is set to 4/5, it is easy to obtain sufficient low oscillating property by setting the length of the submerged buoyant structure in the approaching direction of the entering wave to be equal to or longer than the wavelength of the entering wave by ordinary design in consideration of the structural strength. Will be realized. (5) If the wave breaking structure for breaking the approaching wave is mounted so as to surround the outer periphery of the main floating body, the wave load that the floating structure receives due to the incoming wave can be efficiently reduced. Since the octagonal column-shaped main floating body has an outer peripheral surface formed by a vertical plane, there is an advantage that mounting work of the wave breaking structure becomes easier than in the case of a cylindrical surface.

[Brief description of the drawings]

FIGS. 1A and 1B show a low-swing type floating structure according to a first embodiment of the present invention, wherein FIG. 1A is a plan view and FIG. 1B is an elevation view.

FIGS. 2A and 2B show a low-swing type floating structure as a second embodiment of the present invention, wherein FIG. 2A is a plan view and FIG. 2B is an elevation view.

3A and 3B show a low swaying type floating structure as a third embodiment of the present invention, wherein FIG. 3A is a plan view and FIG. 3B is an elevation view thereof.

FIGS. 4 (a), (b), and (c) are longitudinal sectional views of a main part showing a state in which a wave breaking structure is attached to the low oscillating floating structure of the present invention.

5A and 5B show an example of a conventional floating structure, wherein FIG. 5A is a plan view thereof and FIG. 5B is an elevation view thereof.

6A and 6B show another example of a conventional floating structure, and FIG.
The figure is a plan view, and the figure (b) is a side view.

7A and 7B show an example of a conventional floating structure having a hull form, wherein FIG. 7A is a plan view thereof, and FIG. 7B is a side view thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Submerged buoyancy structure 2 Main floating body 3 Water surface 4 Deck structure 5 Wave breaking structure 5a Horizontal plate 5b Inclined plate 5c Perforated plate

Claims (2)

[Claims] 1. A floating structure comprising a columnar main floating body penetrating a water surface and a flat submerged buoyant structure connected to a lower end of the main floating body and extending outward from an outer periphery of the main floating body. The main floating body is formed in an octagonal column shape,
In all longitudinal sections passing through the plane center of the main floating body, the ratio of the width of the main floating body to the width of the submerged buoyant structure is set to 1/2 to 4/5, Low swing type floating structure. 2. The low swaying floating structure according to claim 1, wherein a wave breaking structure for breaking an incoming wave is mounted so as to surround an outer periphery of the main floating body.