JP2020190152A - Offshore wind turbine monopile foundation support structural body and offshore wind turbine monopile foundation support structure - Google Patents

Abstract

To provide an offshore wind turbine monopile foundation support structural body and a foundation support structure that can stably support an offshore wind turbine using a monopile foundation, and that can construct a monopile foundation even when a sedimentary layer is less than 30 meters.SOLUTION: An offshore wind turbine monopile foundation support structural body 100 is a structural body that supports an offshore wind turbine monopile foundation comprising a foundation pile 940 and a tower section 932 that continues along the foundation pile 940 and extends upward. The offshore wind turbine monopile foundation support structural body 100 comprises: a wall section 10 that can be positioned along the circumferential surface of the foundation pile 940; a through hole 20 that is cut in the wall section 10 and in which the foundation pile 940 can pass; and a bottom surface that extends outward from the lower end of the wall section 10. For an offshore wind turbine monopile foundation support structure 120, while the foundation pile 940 is inserted into the through hole 20, the offshore wind turbine monopile foundation support structural body 100 is set on the see bottom. A weight 80 is placed on the bottom surface that protrudes outward from the lower end of the wall section 10 of the offshore wind turbine monopile foundation support structural body 100.SELECTED DRAWING: Figure 1

Description

The present invention relates to a structure and an auxiliary structure for assisting the foundation for an offshore wind turbine, and more particularly to an auxiliary structure and an auxiliary structure for preventing or suppressing the inclination of the foundation of the offshore wind turbine supported in a monopile form.

In recent years, there has been increasing interest in global environmental issues such as global warming. On the other hand, wind power generation does not emit environmental pollutants such as carbon dioxide and can produce inexhaustible natural energy, so expectations for its development and implementation are increasing.

Offshore wind turbines are roughly divided into floating type that floats on the ocean and moored with anchors, and landing type that is fixed to the seabed. Which type is used is mainly determined in relation to the water depth at which the offshore wind turbine is installed. That is, if the water depth exceeds 0 m and is about 100 m, a landing type offshore wind turbine is preferably selected, and if the water depth is about 100 m to 200 m, a floating offshore wind turbine is preferably selected.

As an example of the floating type, for example, as shown in Patent Document 1, a type in which the tower portion of the wind turbine is supported on the upper part of the floating body and the floating body is moored in a predetermined area with an anchor is known. Floating offshore wind turbines can moor offshore wind turbines in a predetermined area with anchors, but their installation posture is not completely fixed. Therefore, when a strong wind or a wave hits the offshore wind turbine, the floating offshore wind turbine sways and the installation posture changes, and the blades provided on the offshore wind turbine cannot completely receive the wind. As a result, the floating offshore wind turbine has a problem that the amount of power generation with respect to the air volume is lower than the theoretical value and the power generation efficiency is low.

On the other hand, since the landing type foundation shape has a foundation structure fixed to the seabed, the shaking of the offshore wind turbine due to strong winds and waves is suppressed as in the floating body type described above, and the fluctuation of the installation posture is small. Therefore, the offshore wind turbine that adopts the landing type basic shape has a lower construction cost than the floating offshore wind turbine, and it is easy to obtain high power generation efficiency.

As the above-mentioned basic shape of the landing type, a monopile type, a jacket type, a tripod type, a heavy type and the like are known. Among them, the monopile type is preferably used in the sea area where the water depth is shallower than 30 m, and it is said that it occupies about 80% of the share of the foundation shape in the offshore wind power generation facilities in the world.

As exemplified in Patent Document 2, the monopile type foundation shape adopts a configuration in which the tower portion of the offshore wind turbine is continuous on the upper part of one foundation pile. According to the monopile type basic shape, since the installation posture of the offshore wind turbine is fixed, the above-mentioned problem that the installation posture is not stable does not occur. Further, since the monopile type has a simple structure and is used even in a relatively shallow water depth, the installation cost can be suppressed to be smaller than that of other foundation shapes.

Japanese Unexamined Patent Publication No. 2010-216273 Special Table 2016-591234

However, the monopile type foundation shape (hereinafter, also referred to as a monopile foundation) has the following problems. The problems of the conventional monopile foundation will be described with reference to FIG. FIG. 5 is a side view of a conventional offshore wind turbine 930 using a monopile foundation. The offshore wind turbine 930 includes a tower portion 932, a head 934 provided at the upper end of the tower portion 932, and a blade 936 pivotally supported by the head 934. The lower end of the tower portion 932 is connected to the upper part of the foundation pile 940 constituting the monopile foundation. The foundation pile 940 is buried in the sedimentary layer 910 located below the sea level 900, thereby supporting the offshore wind turbine 930. The bedrock 920 exists below the sedimentary layer 910.

In the offshore wind turbine 930 on which a monopile foundation is adopted, the lower end of the foundation pile 940 is buried in the sedimentary layer 910 as described above. Therefore, the offshore wind turbine 930 is prevented from being significantly changed in the installation posture as compared with the floating offshore wind turbine. However, since the offshore wind turbine 930 is supported by a single foundation pile 940, the offshore wind turbine 930 itself or the foundation pile 940 tends to sway intermittently due to the influence of waves and strong winds. The continuous vibration and sway of the foundation pile 940 causes the condition of the sedimentary layer 910 around the foundation pile 940 to deteriorate (that is, to become soft), and as a result, between the foundation pile 940 and the sedimentary layer 910. A gap 912 is formed. Due to the generation of the gap 912, the frictional force between the foundation pile 940 and the sedimentary layer 910 is reduced, and the foundation pile 910 and the offshore wind turbine 930 supported by the foundation pile 910 may be tilted. Further, even if the gap 912 is not formed, the foundation pile 940 may continuously sway or vibrate, which may weaken the sedimentary layer 910 and weaken the resistance in the horizontal direction. As a result, the offshore wind turbine 930 may be tilted.
Therefore, maintenance is performed to fill the gap 912 with a concrete material, a grout material, or the like. However, since the offshore wind turbine 930 and the foundation pile 940 continuously vibrate or sway even after maintenance, a new gap is likely to be formed between the filled concrete and the foundation pile 940, and frequent maintenance is required. There is a problem of Further, it is said that in a conventional offshore wind turbine, when the inclination angle is 2 degrees or more, it is difficult to correct the inclination and it becomes unusable. Therefore, the problem of the inclination of the offshore wind turbine is very serious, and the economic loss when the offshore wind turbine is inclined at a certain angle or more is enormous.

Further, in the monopile foundation, as described above, since the offshore wind turbine 930 is supported by one foundation pile 940, it is said that the depth of the sedimentary layer 910 in which the lower end of the foundation pile 940 can be buried is about 30 m. In Europe and the United States, there are many sedimentary layers 910 with a depth of 30 m or less in coastal waters with a depth of 20 m to 30 m, whereas in coastal waters such as Japan, deposits with sufficient depth to bury conventional monopile foundation piles 940. There are few layers 910. In such sea areas, even if the water depth is shallower than 30 m, it may be difficult to carry out an offshore wind turbine using a monopile foundation.

The present invention has been made in view of the above-mentioned problems. That is, the present invention provides a monopile foundation auxiliary structure for an offshore wind turbine that can stably support an offshore wind turbine using a monopile foundation and can implement the monopile foundation even if the sedimentary layer is less than 30 m. Provides a monopile foundation auxiliary structure for offshore wind turbines.

The monopile foundation auxiliary structure for an offshore windmill of the present invention is a monopile foundation auxiliary structure for an offshore windmill that assists a monopile foundation for an offshore windmill including a foundation pile and a tower portion that extends continuously upward from the foundation pile. A wall portion that can be arranged along the peripheral surface of the foundation pile, a through hole that is partitioned by the wall portion and can penetrate the foundation pile, and a bottom surface portion that extends outward from the lower end portion of the wall portion. It is characterized by having.

Further, the monopile foundation auxiliary structure for an offshore wind turbine of the present invention is an auxiliary structure including a monopile foundation auxiliary structure for an offshore wind turbine, and the monopile foundation auxiliary structure for an offshore wind turbine is provided with the foundation pile penetrating the through hole. It is characterized in that an object is installed on the sea floor and a weight is placed on a bottom surface portion extending outward from the lower end portion of the wall portion of the auxiliary structure.

According to the monopile foundation auxiliary structure for offshore wind turbines and the monopile foundation auxiliary structure for offshore wind turbines of the present invention, the offshore wind turbine can be stably supported, so that the depth of the sedimentary layer is relatively shallow as in the coast of Japan. It is possible to support offshore wind turbines in the sea area with a monopile foundation.
Further, since the monopile foundation auxiliary structure for offshore wind turbines of the present invention can prevent the foundation pile from tilting, the frequency of maintenance for the foundation pile can be reduced. Furthermore, by implementing the present invention, it is possible to substantially improve the durability of the offshore wind turbine because the inclination of the offshore wind turbine is prevented.

It is a side view which shows the monopile foundation auxiliary structure for the offshore wind turbine which concerns on 1st Embodiment of this invention. It is a partial vertical sectional view of the monopile foundation auxiliary structure for the offshore wind turbine shown in FIG. It is a side view which shows the monopile foundation auxiliary structure for the offshore wind turbine which concerns on the 2nd Embodiment of this invention. (A), (b) and (c) are IV-IV end views showing examples of the monopile foundation auxiliary structure for offshore wind turbines used in the second embodiment, respectively. It is a side view of a conventional offshore wind turbine using a monopile foundation.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by the same reference numerals, and duplicate description will be omitted as appropriate.
The various components of the present invention do not have to be individually independent, and a plurality of components are formed as one member, and one component is formed of a plurality of members. It is allowed that a certain component is a part of another component, that a part of a certain component overlaps with a part of another component, and the like. In the illustrated embodiment of the present invention, for the sake of easy understanding, there are cases where a specific member is shown relatively large or small as a whole, but in each case, the dimensional ratio of each configuration of the present invention is shown. It is not limited.

With respect to the description of the present invention or the present specification, when it is referred to as up and down without particular notice, the heavenly direction is referred to as an upward direction from an arbitrary point, and the downward direction relative to the heavenly direction is referred to as a downward direction. Regarding the monopile foundation auxiliary structure for offshore wind turbines, when the vertical direction is described without particular notice, it means the vertical direction when the monopile foundation auxiliary structure for offshore wind turbines is installed on the seabed. Further, with respect to the description of the present specification, the upper end portion is a predetermined length region including the upper end portion, and the lower end portion is a predetermined length region including the lower end portion.
The foundation pile described in relation to the present invention refers to a pile that can be used as a monopile foundation used as a foundation for an offshore wind turbine. The length, diameter, etc. of the foundation pile can be appropriately determined in consideration of the scale of the offshore wind turbine to be supported, the sea area to be installed, the condition of the sedimentary layer, and the like.

(First Embodiment)
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. The first embodiment will be described by taking as an example a monopile foundation auxiliary structure 120 for an offshore wind turbine (hereinafter, also simply referred to as an auxiliary structure 120) including a monopile foundation auxiliary structure 100 for an offshore wind turbine (hereinafter, also simply referred to as an auxiliary structure 100). To do.
FIG. 1 is a side view showing the auxiliary structure 120 according to the first embodiment. FIG. 2 is a partial vertical sectional view of the auxiliary structure 120 shown in FIG.

The auxiliary structure 120 includes an auxiliary structure 100. The auxiliary structure 100 is installed on the seabed with the foundation pile 940 penetrating the through hole 20 provided in the auxiliary structure 100, and the bottom surface of the auxiliary structure 100 extends outward from the lower end of the wall portion 10. A weight 80 is placed on the portion 30 (see FIG. 2) to form an auxiliary structure 120.

The auxiliary structure 100 assists a monopile foundation for an offshore windmill including a foundation pile 940 and a tower portion 932 extending upward continuously to the foundation pile 940. The auxiliary structure 100 includes a wall portion 10 that can be arranged along the peripheral surface of the foundation pile 940, a through hole 20 that is partitioned by the wall portion 10 and can penetrate the foundation pile 940, and an outward direction from the lower end portion of the wall portion 10. A bottom surface portion 30 extending to the surface is provided.
The wall portion 10 that can be arranged along the peripheral surface of the foundation pile 94 means that the inner side surface of the wall portion 10 is configured to be substantially parallel to the peripheral surface of the foundation pile 94. It includes both the case where there is a significant space between the peripheral surface of the wall portion 10 and the outer peripheral surface of the wall portion 10 and the case where there is substantially no significant space. Further, the outward direction from the lower end portion of the wall portion 10 refers to the radial direction centered on the through hole 20.

The auxiliary structure 100 having such a configuration prevents the foundation pile 940 constituting the monopile foundation from inclining, and makes it possible to sustainably and stably support the offshore wind turbine 930. More specifically, the auxiliary structure 100 has a wall portion 10 arranged along the peripheral surface of the foundation pile 940, so that when the foundation pile 940 is slightly inclined in an arbitrary direction, a force in the inclination direction is obtained. It can be a reaction wall that gives a reaction force to. Therefore, the significant inclination of the foundation pile 940 can be satisfactorily prevented.

When the foundation pile 940 is inclined inside the through hole 20, the upper end portion of the wall portion 10 and the inclined foundation pile 940 come into contact with each other. In such a case, a load is applied to the lower end of the wall portion. Therefore, as shown in FIGS. 1 and 2, it is preferable to provide a plurality of support members 66 that support the lower end portion of the wall portion 10. By further improving the stability of the lower end portion of the wall portion 10 in this way, the action of the wall portion 10 as a reaction force wall with respect to the inclined foundation pile 940 is more sufficiently exhibited.
As the support member 66, a rod-shaped body made of iron or steel, or a shaped steel such as H-shaped steel or L-shaped steel is preferably selected. The upper end of the support member 66 is fixed to the outer peripheral surface of the lower end portion of the wall portion 10, and the lower end is fixed to the upper surface of the bottom surface portion 30. The height at which the upper end of the support member 66 is fixed to the outer peripheral surface of the wall portion 10 is not particularly limited, but for example, from the lower end of the wall portion 10 to the sea level 900, the height is less than half from the bottom, and further below. It is reasonable that the height is less than one-third.

The auxiliary structure 120 using the auxiliary structure 100 described above can stably support the monopile foundation for an offshore wind turbine. Therefore, the length of burying the lower end of the foundation pile 940 in the sedimentary layer 910 can be set shorter than that of the conventional one. That is, in the conventional monopile foundation for offshore wind turbines, it is necessary to bury the lower end of the foundation pile 940 in the sedimentary layer 910 at least about 30 m in the sea area shallower than 30 m. However, in the auxiliary structure 120 using the auxiliary structure 100, even if the buried length of the foundation pile 940 with respect to the sedimentary layer 910 is less than 30 m, for example, 25 m or less, or even 20 m or less, the monopile type offshore wind turbine is sufficiently monopile. Can be installed stably.

It is preferable that the members constituting the auxiliary structure 100 have enough strength to give a reaction force when the foundation pile 940 is tilted. For example, the wall portion 10 and the bottom surface portion 30 can be made of an iron material or the like. The thickness of the wall portion 10 and the bottom surface portion 30 is not particularly limited, and can be appropriately designed in consideration of the scale of the offshore wind turbine supported by the foundation pile 940 and the characteristics of the sea area.

The bottom surface portion 30 provided on the auxiliary structure 100 itself exerts an action for stably maintaining the standing posture of the auxiliary structure 100. Further, as shown in FIG. 1, by placing the weight 80 on the upper surface side of the bottom surface portion 30, the stability of the auxiliary structure 100 can be increased, and as a result, the auxiliary structure 120 satisfactorily mounts the monopile for offshore wind turbines. Can assist the foundation.
Further, in general, the foundation pile 940 tends to vibrate continuously due to the vibration propagated from the offshore wind turbine 930, and the sedimentary layer 910 around the foundation pile 940 tends to soften. On the other hand, the bottom surface 80 on which the weight 80 is placed can apply external pressure from above to the sedimentary layer 910 around the foundation pile 940, so that the sedimentary layer 910 is compacted to soften it. It can be suppressed.

The weight 80 may be an object having an appropriate weight, and examples thereof include natural stone, an artificial object such as concrete, a metal such as iron, and gravel. The weight 80 may be a kind or a plurality of materials may be mixed.

Further, the auxiliary structure 120 in which a weight 80 such as a stone is stacked on the upper surface of the bottom surface portion 30 can be a good fishing reef on the seabed. Therefore, it can contribute to the development of the fishery in the sea area where the offshore wind turbine is installed.

The auxiliary structure 100 according to the present embodiment is provided with a side portion 40 that rises upward from the outer edge portion of the bottom surface portion 30. As a result, the auxiliary structure 100 includes a weight accommodating portion 50 having an upper opening composed of a bottom surface portion 30 and a side portion 40. The outer edge portion refers to the outer edge of the bottom surface portion 30 and its vicinity.
By providing the weight accommodating portion 50 having the side portion 40, the weight 80 placed on the upper surface of the bottom surface portion 30 is difficult to be washed away by an ocean current or the like, and the weight 80 is continuously replenished even if the weight 80 is not frequently replenished. The installation posture of the auxiliary structure 100 can be stably maintained. In FIG. 2, the weight 80 housed in the weight accommodating portion 50 is not shown.

The wall portion 10 in the present embodiment is a cylindrical body that is continuous in the vertical direction, and as shown in FIG. 2, the inner diameter 22 of the cylindrical body is configured to be larger than the outer diameter 942 of the foundation pile 940. The difference between the inner diameter 22 and the outer diameter 942 is not particularly limited, but when the axial center of the cylindrical body and the axial center of the foundation pile 940 are overlapped, the inner wall surface of the wall portion 10 which is the cylindrical body and the outer circumference of the foundation pile 940 The distance is preferably, for example, 10 cm or more and 50 cm or less, more preferably 15 cm or more and 40 cm or less, and further preferably 20 cm or more and 30 cm or less. If the distance is less than 10 cm, it may be difficult to penetrate the foundation pile 940 through the through hole 20, and if the distance exceeds 50 cm, the inclination of the foundation pile 940 inside the through hole 20 is significantly allowed. There is a risk of doing so.
Further, in the auxiliary structure 120, when the distance is 10 cm or more, an arbitrary filling 950 can be filled between the foundation pile 940 and the wall portion 10 as shown in FIG. As a result, the standing posture of the foundation pile 940 can be stabilized in the through hole 20 of the wall portion 10 which is a cylindrical body. The filling material 950 is not particularly limited, but for example, a gizzard or sandbag is preferably used. Since the gizzard and sandbag have an irregular shape and can be deformed by an external force, they are suitable as a filling 950 between the foundation pile 940 and the wall portion 10. Further, when the foundation pile 940 sways due to the influence of blade rotation, wind, waves, ocean current, or the like, the sway can be absorbed. By preventing and suppressing the shaking of the foundation pile 940, it is possible to prevent the state of the surrounding sedimentary layer 910 from being softened by the vibration of the foundation pile 940.

Further, although not shown, in the auxiliary structure 120 configured such that the inner diameter 22 of the cylindrical body is larger than the outer diameter 942 of the foundation pile 940, the inner surface of the upper end portion of the wall portion 10 and the peripheral surface of the foundation pile 940. It is also possible to provide a jack at a position where it can be jacked up in the horizontal direction. The jack is preferably provided at a position that can be operated from above the wall portion 10. The number of the jacks may be one, but preferably two or more. By providing the jack that can be pressed in the horizontal direction, it is possible to adjust the inclination of the foundation pile 940. The jack may be installed in advance from the stage before the foundation pile 940 tilts to help prevent tilting, or after the tilting is confirmed, the jacks are placed at appropriate positions and jacked in the horizontal direction. The inclination of the foundation pile 940 can be adjusted by raising it. In addition, since the load on the wall portion 10 becomes large at the time of jacking up, the area where the jack is planned to be arranged may be reinforced. The reinforcement of the wall portion 10 includes, but is not limited to, means such as providing a protective layer with an iron member or the like in a predetermined region to increase the thickness.

In the auxiliary structure 100 of the present embodiment, a jack installation base 68 for installing a jack (not shown) is provided on the inner surface of the wall portion 10. The position where the jack installation base 68 is provided is not particularly limited, but for example, from the viewpoint that the operator can easily operate the jack-up from above the wall portion 10, it is preferable to provide the jack installation base 68 at the upper end portion of the wall portion 10. The jack installation table 68 is, for example, a table that extends substantially horizontally from the inner surface of the wall portion 10, and is provided continuously or intermittently in the circumferential direction on the inner surface.
However, in the present invention of the mode of installing the jack, the method of installing the jack is not limited to the mode of using the jack installation base 68. For example, a jack device having a magnet portion including a permanent magnet or an electromagnet may be used, and the magnet portion and the inner surface of the wall portion 10 made of a magnetic material may be magnetically attracted to fix the jack device to the inner surface. it can. When the wall portion 10 itself is not a magnetic material, a magnetic material layer is provided in a predetermined region on the inner surface of the wall portion 10, and the magnetic material layer is brought into contact with the magnet portion provided in the jack device, and the magnetic force is applied. The jack device may be fixed.

The wall portion 10 includes a wall surface that continuously or intermittently faces the outer circumference of the foundation pile 940 that is penetrated through the through hole 20. The wall portion 10 in the present embodiment is a cylindrical body that covers the outer circumference of the foundation pile 940 from the vicinity of the seabed to a predetermined height. The cylindrical body may be composed of substantially continuous surfaces, or may have a partially opened portion such as a hole for water passage penetrating in the thickness direction.
The height of the wall portion 10 is not particularly limited. From the viewpoint of ensuring a sufficient height of the wall portion 10 that can be a reaction force wall of the foundation pile 940 and minimizing the inclination of the foundation pile 940, the upper end of the wall portion 10 is near the sea level 900, particularly. It is preferably located above sea level 900.

As shown in FIG. 2, in the present embodiment, the work space 116 is provided above the wall portion 10. The work space 116 is a space whose diameter is expanded with respect to the inner diameter 22 of the wall portion 10, and is a floor portion 112 extending outward from the upper end of the wall portion 10 and a side wall 114 extending upward from the outer edge of the floor portion 112. It is composed of.
In other words, the floor portion 112 is a substantially horizontal step extending in a direction away from the upper end of the wall portion 10 with respect to the foundation pile 940. The work space 116 is a space that allows an operator to perform maintenance work of the foundation pile 940 on the floor portion 112, and in consideration of workability, the distance 118 from the upper end of the wall portion 10 to the inner surface of the side wall 114. Is preferably 30 cm or more, more preferably 40 cm or more, and further preferably 50 cm or more. Further, in consideration of the stability and balance of the auxiliary structure 100, the distance 118 is preferably 300 cm or less, more preferably 250 cm or less, and further preferably 200 cm or less.

The vertical positional relationship between the upper end of the wall portion 10 and the upper end of the foundation pile 940 is not particularly limited, but from the viewpoint of facilitating maintenance work, the upper end of the foundation pile 940 is above the upper end of the wall portion 10. It is preferable to be located. Further, when the work space 116 is provided, it is preferable that the upper end of the foundation pile 940 exists at a height equal to or higher than the upper end of the side portion 40 from the viewpoint that the worker standing on the floor portion 112 can easily work.

In the present embodiment, the following configurations are further added in order to make the auxiliary structure 100 more stable.

The auxiliary structure 100 is provided with spikes 70 extending downward from the lower surface of the bottom surface portion 30. In this embodiment, a plurality of spikes 70 are provided. When the spike 70 pierces the sedimentary layer 910, the installation stability of the auxiliary structure 100 can be improved. The spike 70 is a long member made of an iron material or the like, and it is preferable that the spike 70 is appropriately formed with a sharp tip so that the spike 70 can easily stick to the sedimentary layer 910.
The number of spikes 70 provided on the lower surface of the bottom surface portion 30 is not particularly limited, and the plurality of spikes 70 may be arranged in an orderly manner in a predetermined direction or may be randomly arranged.

Further, the auxiliary structure 100 includes an anchor 90 attached at an arbitrary position. FIGS. 1 and 2 show an example in which an anchor chain is used as the anchor 90. One end of the anchor chain (anchor 90) is fixed to the upper end of the side 40 constituting the weight accommodating portion 50, and a claw portion 92 is provided at the other end so that the anchor chain can be easily locked to the seabed. ing. In the auxiliary structure 100, one or two or more anchor chains, which are anchors 90, may be installed. For example, two anchors 90 are paired and positioned 180 degrees from each other with the through hole 20 as the center. It is preferable that it is provided in.
Although not shown, the anchor 90 may be a chain other than the anchor chain. For example, as another example of the anchor 90, a sinker that exerts a weight effect on its own weight can also be used.

By providing the spike 70 and the anchor 90 described above, when adjusting the pressure of the inclination of the foundation pile 940 or the inclination of the foundation pile 940 with the jack described later or the inclination adjusting tool described later with respect to the wall portion 10. It is possible to prevent the auxiliary structure 100 from being displaced or the auxiliary structure 100 from being tilted when the pressure is applied. Since the installation posture of the auxiliary structure 100 is stable even when the above-mentioned pressure is applied, the wall portion 10 satisfactorily exerts an action as a reaction force wall against the inclined foundation pile 940. Can be done.

The method of installing the auxiliary structure 100 is not particularly limited, but for example, the foundation pile 940 is driven into the sedimentary layer 910 in a predetermined sea area, and then the auxiliary structure is installed from above the foundation pile 940 using a large crane vessel or the like. It can be installed by covering 100 and passing the foundation pile 940 through the through hole 20. After that, the weight 80 may be stacked on the upper surface of the bottom surface portion.

(Second Embodiment)
Hereinafter, the monopile foundation auxiliary structure 220 for offshore wind turbines of the present invention (hereinafter, also simply referred to as auxiliary structure 220) including the monopile foundation auxiliary structure 200 for offshore wind turbines of the present invention (hereinafter, also simply referred to as auxiliary structure 200). The second embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a side view showing the auxiliary structure 220 according to the second embodiment of the present invention. 4 (a), 4 (b), and 4 (c) are IV-IV end views showing examples of aspects of the auxiliary structure 200 used in the second embodiment, respectively.

The auxiliary structure 200 according to the second embodiment will be described above in that it does not have a work space 116 and is provided with an inclination adjusting hole 60, and does not have a side portion 40 and an anchor 90 continuous with the bottom surface portion 30. Unlike the auxiliary structure 100, other configurations are the same. Therefore, in the following description, the configuration peculiar to the auxiliary structure 200 will be mainly described, and the description of the first embodiment will be referred to as appropriate for other configurations.

Like the auxiliary structure 100, the auxiliary structure 200 is a cylindrical body having a through hole 20, and has a bottom surface portion 30 at the lower end. In the auxiliary structure 220 including the auxiliary structure 200, the foundation pile 940 is penetrated through the through hole 20, whereby the offshore wind turbine 930 can be supported stably and continuously.

The auxiliary structure 200 is provided with a plurality of tilt adjusting holes 60 at the upper end of the wall portion 10 for penetrating in the thickness direction and inserting the tilt adjusting tool 62 (see FIG. 4). In FIG. 3, the inclination adjuster 62 is not shown. In each of the two aspects shown in FIG. 4, an example in which four inclination adjusting holes 60 are provided is shown, but the number of inclination adjusting holes 60 is not limited to this, and may be less than four or more. You may.
The upper end portion of the wall portion 10 referred to here does not indicate a particularly limited height position, but the inclination adjusting hole 60 is in the vertical direction of the wall portion 10 due to the ease of angle adjustment work. It is preferably provided above the sea level 900, more preferably near the sea level 900, and even more preferably above the sea level 900.

Further, FIGS. 3 and 4 show an example in which a plurality of tilt adjusting holes 60 are provided at the same height position, but the present invention is not limited to this, and a plurality of tilt adjusting holes 60 having different height positions are shown. May be provided. As a more specific example, although not shown, a plurality of inclination adjusting holes 60 are provided in the circumferential direction at an arbitrary height position A on the wall portion 10, and the height is relatively low with respect to the height position A. A plurality of inclination adjusting holes 60 may be provided in the circumferential direction at the vertical position B. In other words, the inclination adjusting hole 60 may be provided at the upper end portion of the wall portion 10 and may be further provided below this (arbitrary position between the upper end portion and the lower end portion of the wall portion 10). ..
In this way, by adjusting the inclination using the inclination adjusting holes 60 having different height positions, it is possible to disperse the force of pushing or pulling the foundation pile 940 for the inclination adjustment, and the force with respect to the foundation pile 940 can be dispersed. The load can be reduced.

The inclination adjuster 62 is adjusted so that when the foundation pile 940 is inclined inside the through hole 20 of the auxiliary structure 200, the inclination angle is reduced, and preferably, the inclination angle is adjusted to 0 degree. It is a member of. The inclination adjusting tool 62 is a member that can physically act on the foundation pile 940 from the outside of the wall portion 10 through the inclination adjusting hole 60. Here, the physical action means applying a force to push or pull the inclined foundation pile 940 in a predetermined direction.

For example, as the tilt adjuster 62, as shown in FIG. 4A, a bolt 62a having a male-threaded shaft portion and a head can be used. In such a case, a female thread corresponding to the male thread is cut in the inclination adjusting hole 60.
As shown in FIG. 4A, the bolt 62a may be installed in advance before the foundation pile 940 is tilted. By bringing the tips of the shafts of the plurality of bolts 62a installed in advance into contact with the peripheral surface of the foundation pile 940 installed upright at a desired angle, the inclination of the foundation pile 940 can be prevented. .. When the foundation pile 940 is tilted, the plurality of bolts 62a can be tightened or loosened to adjust the foundation pile 940 to a desired angle.

Although not shown, in normal times, the bolt 62a is not installed in the tilt adjusting hole 60, and when the foundation pile 940 is tilted, the bolt 62a is inserted into one or more tilt adjusting holes 60. Then, the tip of the bolt 62a may push the foundation pile 940 back in the direction opposite to the inclination direction.

FIG. 4B shows a different example of the tilt adjuster 62. The inclination adjuster 62 shown in FIG. 4B is a wire 62b. The wire 62b is inserted from one inclination adjusting hole 60, goes around the outer circumference of the foundation pile 940, and is led out from the other inclination adjusting hole 60 to the outside. By pulling both ends of the wire 62b, the foundation pile 940 can be pulled in the direction 65 from the cross-sectional center 63 of the foundation pile 640 toward the intersection 64 of the wires 62b. One or two or more wires 62b may be arranged in advance as described above, and when the foundation pile 940 is tilted, the angle of the foundation pile 940 may be adjusted by pulling both ends of the appropriate wire 62b. Alternatively, after the inclination of the foundation pile 940 is confirmed, the wire 62b may be inserted into an appropriate inclination adjusting hole 60 to adjust the angle of the foundation pile 940 in the same manner.

In the present embodiment, an example in which the above-described tilt adjusting tool 62 is used has been described as an embodiment of the tilt adjusting hole 60, but the present invention is not limited thereto. For example, an inclination adjusting hole 60 (not shown) having a size that allows the jack to be taken in and out may be formed at an arbitrary position on the wall portion 10. The inclination adjusting hole 60 may exist in the sea instead of near the sea level 900. A plurality of tilt adjusting holes 60 that can be jacked in and out are provided, and when the foundation pile 940 is tilted, a jack is inserted between the wall portion 10 and the foundation pile 940 from an appropriately selected tilt adjusting hole 60 to form a foundation. It is also possible to jack up the pile 940 to adjust the inclination. The jack installation table 68 (see FIG. 2) described in the first embodiment may be provided in the vicinity of the inclination adjusting hole 60 in which the jack can be taken in and out.

The method of pulling the end portion of the wire 62b is not particularly limited. The wire 62b may be pulled so as to be wound up mechanically, or the wire 62b may be pulled as appropriate using a pulley (not shown).

By the way, in FIG. 4B, both ends of the wire 62b are in a free state, but both ends of the wire 62b installed in advance as shown in FIG. 4B are wall portions without slack. It may be fixed at any place of 10 or the like. By fixing the wire 62b sown on the foundation pile 940 in a state where there is no slack in this way, the vibration absorbing effect of the foundation pile 940 can be exhibited, and the inclination prevention effect of the foundation pile 940 is also exhibited. obtain.
Note that FIG. 4B shows an embodiment in which one wire 62b is installed, but the present invention is not limited to this. For example, as shown in FIG. 4C, two wires 62b may be installed in advance. As a result, by applying tension to the foundation pile 940 in different directions (for example, 180 degrees opposite directions), the inclination of the foundation pile 940 can be prevented more satisfactorily, and the inclination adjustment becomes easy. Of course, six inclination adjusting holes 60 may be provided to apply tension to the foundation pile 940 in three directions.

By the way, the wall portion 10 may be formed of an integrally formed cylindrical body, or several parts may be fixed to each other to form one cylindrical body. For example, although not shown, it is also possible to prepare two or more short small cylinders and connect them in the vertical direction to form a cylinder having a desired length. Alternatively, as shown in FIG. 4A, two or more long objects forming an arc with a semicircular cross section may be used as the wall portion 10, and they may be combined to form a cylindrical body having a circular cross section. Specifically, for example, FIG. 4A shows an embodiment in which a part divided into two in a cross section is used. The first wall portion 10a having a substantially semicircular cross section and the second wall portion 10b having a substantially semicircular cross section are opposed to each other in a direction forming a circular cross section, and are formed at the end of the cross section of the first wall portion 10a. The first protruding portion 12a provided is brought into contact with the second protruding portion 12b provided at the end of the cross section of the second wall portion 10b, and the first protruding portion 12a and the second protruding portion 12b are connected. It is also possible to form a cylindrical wall portion 10 by fixing the connecting members 14 to each other.

The auxiliary structure 200 according to the present embodiment has a bottom surface portion 30 and no side portion 40. The present invention includes an embodiment that does not have a vessel-shaped weight accommodating portion 50 as shown in the first embodiment.
For example, the bottom surface portion 30 in the present embodiment is a disk-shaped member extending in the radial direction from the lower end of the wall portion 10 which is a cylindrical body. By placing the weight 80 so as to cover the entire disk-shaped bottom surface portion 30, the auxiliary structure portion 200 can be sufficiently stabilized. The diameter of the disk should be adjusted according to the scale of the offshore wind turbine. In this respect, the same applies to the bottom surface portion 30 in the first embodiment.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and includes various modifications, improvements, and the like as long as the object of the present invention is achieved.
For example, the first embodiment describes the auxiliary structure 100 having the work space 116, and the second embodiment describes the auxiliary structure 100 having the inclination adjusting hole 60. However, the present invention describes the work space 116 and the inclination. It includes an embodiment including both adjusting holes 60.
The anchor 90 described in the first embodiment is not limited to the mode of being fixed to the side portion 40 of the weight accommodating portion 50, and one end may be fixed at an arbitrary position on the outer circumference of the wall portion 10, for example.
Further, in the present invention, the wall portion 10 or the work space 116 arranged near the sea level 900 or above the sea level 900 can also serve as a protective structure for protecting the foundation pile 940 penetrating the auxiliary structure 100. For example, work boats or passers-by may move around the foundation pile 940 for maintenance of the foundation pile 940 or the offshore windmill 930, and these ships collide with the foundation pile 940 and damage the foundation pile 940. An accident may occur. On the other hand, in the present invention, since the wall portion 10 or the work space 116 exists at a position covering the foundation pile 940, the impact due to the collision of the ship can be absorbed by these, so that the foundation pile 940 is protected.

The present invention described above prevents the inclination of the offshore wind turbine supported by the monopile foundation, and makes it possible to adjust the inclination even when the offshore wind turbine is inclined. Therefore, the present invention greatly contributes to greatly improving the durability of the offshore wind turbine and extending the life of the offshore wind turbine, and further contributes to the practical use of the offshore wind turbine.
Further, by using the present invention, the bearing capacity of the monopile foundation can be substantially improved. Therefore, it is possible to implement an offshore wind turbine using a monopile foundation even in a sea area where the sedimentary layer is shallow. Therefore, the present invention also contributes to increasing the versatility of the offshore wind turbine.
Further, the auxiliary structure of the present invention has a bottom surface portion on which a weight is placed. A new fishing reef is formed by stacking weights such as stones on the bottom. Therefore, the present invention not only contributes to the generation of clean energy by the offshore wind turbine, but also contributes to the reflection of the fishery, and has very high industrial applicability.

The above embodiment includes the following technical ideas.
(1) A monopile foundation auxiliary structure for an offshore windmill that assists a monopile foundation for an offshore windmill provided with a foundation pile and a tower portion that extends continuously upward from the foundation pile.
Walls that can be placed along the peripheral surface of the foundation pile and
A through hole that is partitioned into the wall and can penetrate the foundation pile,
The bottom surface extending outward from the lower end of the wall and
A monopile foundation auxiliary structure for offshore wind turbines, which is characterized by being equipped with.
(2) It has a side portion that stands upward from the outer edge portion of the bottom surface portion, and has a side portion.
The monopile foundation auxiliary structure for an offshore wind turbine according to (1) above, which includes a weight accommodating portion having an upper opening composed of the bottom surface portion and the side portion.
(3) The wall portion is a cylindrical body that is continuous in the vertical direction.
The monopile foundation auxiliary structure for offshore wind turbines according to (1) or (2), wherein the inner diameter of the cylindrical body is larger than the outer diameter of the foundation pile.
(4) Any one of (1) to (3) above, in which a plurality of inclination adjusting holes are provided at the upper end of the wall portion for inserting the inclination adjusting tool through the wall portion in the thickness direction. Monopile foundation auxiliary structure for offshore wind turbines as described in section.
(5) The monopile foundation auxiliary structure for an offshore wind turbine according to any one of (1) to (4) above, which is provided with spikes extending downward from the lower surface of the bottom surface portion.
(6) An auxiliary structure including the monopile foundation auxiliary structure for an offshore wind turbine according to any one of (1) to (5) above.
The monopile foundation auxiliary structure for offshore wind turbines is installed on the seabed with the foundation pile penetrating the through hole.
A monopile basic auxiliary structure for offshore wind turbines, characterized in that a weight is placed on a bottom surface portion extending outward from the lower end portion of the wall portion of the auxiliary structure.

10 ... Wall part 10a ... First wall part 10b ... Second wall part 12a ... First protruding part 12b ... Second protruding part 14 ... Connecting member 20 ... Through hole 22 ... Inner diameter 30 ... Bottom part 40 ... Side part 50 ... Weight accommodating part 60 ... Tilt adjusting hole 62 ... Tilt adjusting tool 62a ... Bolt 62b ... Wire 63 ...・ ・ Cross-section center 64 ・ ・ ・ Intersection 65 ・ ・ ・ Direction 66 ・ ・ ・ Support member 68 ・ ・ ・ Jack installation stand 70 ・ ・ ・ Spike 80 ・ ・ ・ Weight 90 ・ ・ ・ Anchor 100, 200 ・ ・ ・ Offshore wind turbine Monopile foundation auxiliary structures for offshore wind turbines 120, 220 ... Monopile foundation auxiliary structures for offshore wind turbines 112 ... Floor 114 ... Side walls 116 ... Work space 118 ... Distance 900 ... Sea surface 910 ... Sedimentary layer 912 ... Gap 920 ... Bedrock 930 ... Offshore wind turbine 932 ... Tower part 934 ... Head 936 ... Blade 940 ... Foundation pile 942 ... Outer diameter 950 ... Filling

Claims (6)

A monopile foundation auxiliary structure for an offshore windmill that assists a monopile foundation for an offshore windmill provided with a foundation pile and a tower portion that extends continuously upward from the foundation pile.
A wall portion that can be arranged along the peripheral surface of the foundation pile and
A through hole partitioned by the wall and capable of penetrating the foundation pile,
A bottom surface extending outward from the lower end of the wall and
A monopile foundation auxiliary structure for offshore wind turbines, which is characterized by being equipped with. It has a side portion that rises upward from the outer edge portion of the bottom surface portion, and has a side portion.
The monopile foundation auxiliary structure for an offshore wind turbine according to claim 1, further comprising a weight accommodating portion having an upper opening composed of the bottom surface portion and the side portion. The wall portion is a cylindrical body that is continuous in the vertical direction.
The monopile foundation auxiliary structure for an offshore wind turbine according to claim 1 or 2, wherein the inner diameter of the cylindrical body is larger than the outer diameter of the foundation pile. The offshore wind turbine according to any one of claims 1 to 3, wherein a plurality of inclination adjusting holes are provided at the upper end portion of the wall portion so as to penetrate in the thickness direction of the wall portion and insert the inclination adjusting tool. Monopile foundation auxiliary structure for. The monopile foundation auxiliary structure for an offshore wind turbine according to any one of claims 1 to 4, which is provided with spikes extending downward from the lower surface of the bottom surface portion. An auxiliary structure including the monopile foundation auxiliary structure for an offshore wind turbine according to any one of claims 1 to 5.
With the foundation pile penetrating the through hole, the monopile foundation auxiliary structure for offshore wind turbines is installed on the seabed.
A monopile basic auxiliary structure for offshore wind turbines, characterized in that a weight is placed on a bottom surface portion extending outward from the lower end portion of the wall portion of the auxiliary structure.

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