JP7174639B2 - Substructure of foundation for offshore wind power generation and construction method for substructure of foundation for offshore wind power generation - Google Patents

Description

The present invention relates to a substructure for offshore wind power generation foundations and a construction method for a substructure for offshore wind power generation foundations.

The foundation types of offshore wind turbines include monopile foundations, pile foundations, and gravity foundations. In pile foundations, a jacket may be installed on the foundation and a wind turbine tower may be joined on top of the jacket. As a construction method for the piles that support the jacket, an excavation drill inserted inside the pile guide member is used to form an excavation hole in the submerged ground. There is a method of filling cement milk in the gap between the borehole and the inside of the hollow pile (see, for example, Patent Document 1).

Japanese Patent No. 3843045

However, in the foundation format using piles as in the method described in Patent Document 1, the pull-out resistance of the pile generally depends on the frictional force on the peripheral surface of the pile, so the embedding depth is sufficiently long (for example, about 30 to 40 m). ), but if the submerged ground is bedrock, it may take time to drive the piles, or the bedrock may crack during pile driving and the expected bearing capacity may not be obtained. However, it is not easy to construct a gravity foundation that does not involve pile driving and that is large enough to fit the size of offshore wind turbines, which have become larger in recent years.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and aims to provide a lower structure for a foundation for offshore wind power generation that can reliably fix a jacket structure to the bottom of the water without driving piles; The object is to provide a construction method for the substructure of the foundation for offshore wind power generation.

In order to achieve the above object, a first invention provides a substructure for an offshore wind power generation foundation, comprising: a plurality of legs formed of hollow steel pipes; a connecting member connecting the plurality of legs; The lower end of the leg is supported by a support installed in the underwater ground, and the jacket structure has one end fixed in the underwater ground and the other end formed on the water surface. The bottom structure of the foundation for offshore wind power generation is fixed to the underwater ground by a ground anchor fixed to a fixed fixing portion, and the ground anchor is arranged so as to penetrate the support portion .
A second invention is a substructure for an offshore wind power generation foundation, comprising a jacket structure comprising a plurality of legs formed of hollow steel pipes and a connecting member connecting the plurality of legs. , the lower end of the leg is supported by a support installed in the sea bed, one end of the jacket structure is fixed to the sea bed by a ground anchor anchored in the sea bed, and the ground anchor is fixed to the ground anchor. is arranged in a space surrounded by the legs and the connecting members.

In the first and second inventions, the lower end of the leg is supported by the support part installed in the seabed ground, and the jacket structure is fixed to the seabed ground by the ground anchor, so that the pushing force from the jacket structure can be transmitted from the leg to the submerged ground by the support part, and the pull-out force can be resisted by the ground anchor. Therefore, the jacket structure can be reliably fixed to the bottom of the water without driving piles.

In the first invention, the other end of the ground anchor is fixed to the fixing portion formed on the water surface, thereby eliminating the need for underwater diver work when constructing the ground anchor.

In the first invention, it is desirable that the ground anchor is arranged through the inside of the leg.
As a result, the ground anchor can be protected from corrosion due to seawater, damage due to drifting objects, and the like.

In the first and second inventions, a plurality of ground anchors may be provided, and the plurality of ground anchors may be anchored at different depths in the underwater ground.
Thereby, even when a plurality of ground anchors are arranged close to each other, each ground anchor can be reliably anchored in the seabed ground.

The inside of the leg may be filled with a filling material.
Thereby, the weight of the jacket structure can be appropriately adjusted.

In the first invention, the fixing portion is formed using a fixing plate fixed to the above-water portion of the leg, the fixing plate has a guide hole, and the support portion is a bottom plate installed on the underwater ground. wherein the bottom plate has a sheath tube arranged at a position corresponding to the guide hole when viewed from the axial direction of the leg, and the ground anchor is arranged through the guide hole and the sheath tube is desirable.
Thereby, the ground anchor can be reliably arranged at a predetermined position.

When the supporting portion is a bottom plate, an internal corner portion formed by the upper surface of the bottom plate and the outer peripheral surface of the leg may be reinforced with a rib material. Also, the bottom plate may comprise an upper plate, a lower plate, and vertical rib members connecting the upper plate and the lower plate.
As a result, the weight of the bottom plate can be reduced and the strength can be ensured.

In the first and second inventions, the support portion may be foot protection concrete for the leg formed by excavating the submerged ground.
As a result, applicability to unevenness and inclination of the bottom of the water can be enhanced.

A third invention is a method for constructing a substructure of a foundation for offshore wind power generation, comprising a step a of constructing a jacket structure having a plurality of legs formed of hollow steel pipes; a step b of supporting the lower end of the leg with a support installed in the sea bed; and a step c of fixing the jacket structure to the sea bed with a ground anchor penetrating the support . , and in the step c, one end of the ground anchor is fixed in the underwater ground, and the other end is fixed to a fixing portion formed in the water surface . This is the construction method of the substructure.
A fourth invention is a method for constructing a substructure of an offshore wind power generation foundation, comprising constructing a jacket structure having a plurality of legs formed of hollow steel pipes and a connecting member connecting the plurality of legs. a step of transporting the jacket structure to the site, and a step b of supporting the lower ends of the legs with supports installed on the submerged ground; and a step c of fixing to the waterbed ground by a ground anchor arranged in a space, wherein in the step c, one end of the ground anchor is anchored in the waterbed ground. This is the construction method of the lower structure of the foundation.

In the third and fourth inventions, the lower end of the leg is supported by the support part installed in the seabed ground, and the jacket structure is fixed to the seabed ground by the ground anchor, so the pressing force from the jacket structure is transmitted to the submerged ground by the supporting part, and the pull-out force can be resisted by the ground anchor. Therefore, the jacket structure can be fixed to the bottom of the water without driving piles.

In the third invention, the fixing portion is formed using a fixing plate fixed to the above-water portion of the leg, the fixing plate has a guide hole, and the support portion is a bottom plate that supports the leg, The bottom plate has a sheath pipe arranged at a position corresponding to the guide hole when viewed from the axial direction of the leg, the step a attaches the bottom plate to the lower end of the leg, and the step b The bottom slab is placed on the seabed ground, and in step c, the ground anchor is placed by drilling the seabed ground using the guide hole and the sheath pipe as a guide, and the other end of the ground anchor is fixed to the ground anchor. It is desirable to have it fixed to the plate .

If the bottom slab is attached to the lower end of the leg in step a, work on or in the water can be minimized. In addition, by arranging the ground anchor through the inside of the leg and penetrating the bottom slab in step c, the ground anchor can be reliably placed in a predetermined position, and the ground anchor can be protected from corrosion by seawater and damage by drifting objects. can be protected. Furthermore, if the other end of the ground anchor is fixed to the fixing portion formed on the water portion of the lower structure, diver work in the water is not required when constructing the ground anchor.

Further, the support portion is foot protection concrete for the leg, and in the step b, after the lower end portion of the leg is placed in the excavated portion excavated in the underwater ground, the excavated portion is filled with concrete to form the Foot protection concrete may be formed, and in the step c, the ground anchor may be placed through the inside of the leg, and the other end of the ground anchor may be fixed to a fixing portion formed on the water surface.

If foot protection concrete is formed in step b, applicability to unevenness and inclination of the bottom of the water can be enhanced. Further, if the ground anchor is placed through the inside of the leg in step c, the ground anchor can be protected from corrosion due to seawater, damage due to drifting objects, and the like. Furthermore, if the other end of the ground anchor is anchored to the anchoring portion formed in the sea portion of the lower structure, diver work in the water is not required when constructing the ground anchor.

ADVANTAGE OF THE INVENTION According to this invention, the lower structure of the foundation for offshore wind power generation and the construction method of the lower structure of the offshore wind power generation foundation which can fix a jacket structure to the bottom of the water reliably without driving a pile can be provided.

FIG. 4 shows a process of constructing the jacket structure 1; The figure which shows the joint part vicinity of the leg 3 and the bottom plate 5. FIG. FIG. 4 is a diagram showing a process of installing the jacket structure 1 on the bedrock 19; FIG. 4 is a diagram showing a process of fixing the jacket structure 1 to the rock 19; FIG. 4 is a diagram showing a process of filling filling sand 31; The figure which shows the lower structure 49a. FIG. 4 shows lower structures 49b and 49c; The figure which shows the lower structure 49d. The figure which shows the example of other bottom plates 5a and 5b. The figure which shows the process of constructing the lower structure 49e. The figure which shows the process of constructing the lower structure 49e. The figure which shows the process of constructing the lower structure 49e. FIG. 4 is a diagram showing an example in which an optical fiber sensor 45 is incorporated in the ground anchor 25 inside the leg 3;

A first embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram showing the steps of constructing a jacket structure 1. FIG. FIG. 2 shows the vicinity of the joint between the leg 3 and the bottom plate 5. As shown in FIG. FIG. 2 is a cross-sectional view taken along arrows AA shown in FIG. FIG. 3 is a diagram showing a process of installing the jacket structure 1 on the bedrock 19. As shown in FIG.

As shown in FIGS. 1 to 3, the jacket structure 1 includes a plurality of legs 3 made of hollow steel pipes, connecting members 7 connecting the legs 3, and the like.

The lower end of the leg 3 is supported by a bottom plate 5 which is a supporting portion. The bottom plate 5 is composed of a top plate 9, a bottom plate 11, vertical rib members 13, and the like. The vertical rib member 13 connects the upper plate 9 and the lower plate 11 . An internal corner formed by the upper plate 9 of the bottom plate 5 and the outer peripheral surface of the leg 3 is reinforced with a rib material 15 . With such a configuration, it is possible to reduce the weight of the bottom plate 5 and ensure its strength.

The bottom plate 5 is formed, for example, by joining a plurality of H-shaped steels. In this case, the flanges serve as the upper plate 9 and the lower plate 11, and the web serves as the longitudinal rib member 13.

A sheath tube 17 is fixed to the bottom plate 5 so as to pass through the upper plate 9 and the lower plate 11 . The sheath tube 17 is provided parallel to the axial direction of the leg 3 .

A fixing plate 23 (see FIG. 3) is provided on the upper portion of the leg 3 . The fixing plate 23 has a guide hole 24 and a filling hole (not shown). The guide hole 24 is provided at a position corresponding to the sheath tube 17 fixed to the bottom plate 5 when viewed from the axial direction of the leg 3 . It is desirable that the filling hole be provided so as not to be continuous with the guide hole 24 . The fixing plate 23 is made of steel and fixed to the inner peripheral surface of the leg 3 with a bracket (not shown).

In the process shown in FIG. 1, a jacket structure 1 is constructed on land. A bottom plate 5 is attached to the leg 3 of the jacket structure 1 . In the process shown in FIG. 3, the jacket structure 1 to which the bottom slab 5 is attached is transported to the site by a crane ship and set on the bedrock 19 at the bottom of the water. The bottom slab 5 contacts the bedrock 19 and supports the lower end of the leg 3 .

FIG. 4 is a diagram showing the process of fixing the jacket structure 1 to the rock 19. As shown in FIG. In the process shown in FIG. 4 , a drilling machine (not shown) installed above the water surface 21 of the jacket structure 1 is used to drill the rock 19 from the inside 29 of the leg 3 . During drilling, the guide hole 24 and the sheath tube 17 are used as guides.

Then, the ground anchor 25 is driven through the leg 3 and the sheath tube 17 , and the lower end of the ground anchor 25 is fixed to the bedrock 19 by the anchor body 27 . At this time, if a plurality of ground anchors 25 are close to each other, it is desirable to form the anchor bodies 27 at different depths within the bedrock 19 of the water bottom as shown in FIG. The anchor bodies 27 may be formed at the same depth within the rock 19 if the ground anchors 25 are not in close proximity. The upper end of the ground anchor 25 is fixed to the fixing plate 23 positioned above the water surface 21 by the fixing tool 33 . Thus, the jacket structure 1 is fixed to the bedrock 19 of the water bed by the ground anchors 25 passing through the inner part 29 of the leg 3 and penetrating the bottom slab 5 .

Ground anchors have established design standards and construction methods for constructing anchor bodies in rock, and the diameter and depth of drilled holes are smaller than in the case of constructing piles in rock. Therefore, cracks are less likely to occur in the rock 19 during drilling, and the anchor body 27 can be fixed to the rock 19 to reliably obtain a bearing force.

FIG. 5 is a diagram showing the process of filling the filling sand 31. As shown in FIG. In the process shown in FIG. 5 , filling sand 31 is filled into the inside 29 of the leg 3 using a filling hole (not shown) provided in the fixing plate 23 . The filling sand 31 may be filled up to the height of the fixing plate 23 as shown in FIG. 5(a), or may be filled up to a predetermined height in water as shown in FIG. 5(b). The filling amount is determined in consideration of the force acting on the leg 3 due to the weight of the filling sand 31 . This completes the lower structure 49 of the foundation for offshore wind power generation.

Thus, according to the first embodiment, since the jacket structure 1 including the bottom slab 5 is manufactured on land, there is no need to join the legs 3 to the bottom slab 5, which is the support part, in the water or at the bottom of the water. Work using a self-elevating work barge can be minimized.

In the lower structure 49, the bottom slab 5 that supports the leg 3 and the ground anchor 25 are used together. It becomes possible to have a structure that resists. Therefore, the jacket structure 1 can be fixed to the bottom of the water without driving piles.

In the lower structure 49, the ground anchor 25 is arranged through the inside 29 of the leg 3 and through the bottom slab 5. Therefore, the ground anchor 25 can be reliably arranged at a predetermined position, and corrosion by sea water and flotsam are prevented. It is possible to protect the ground anchor 25 from damage caused by, for example. In addition, since the other end of the ground anchor 25 is fixed to the fixing portion formed in the above-water portion of the leg 3, diver work in water is not required when constructing the ground anchor 25. - 特許庁Furthermore, by filling the leg 3 with filling sand 31, the weight of the jacket structure 1 can be appropriately adjusted.

Other examples of the present invention will be described below as second to fifth embodiments. In each embodiment, points different from the embodiments described so far will be described, and descriptions of similar configurations will be omitted by attaching the same reference numerals in the drawings and the like. In addition, the configurations described in each embodiment, including the first embodiment, can be combined as necessary.

A second embodiment will be described. FIG. 6 shows a lower structure 49a according to a second embodiment of the invention.

This lower structure 49a is mainly different from the lower structure 49 of the first embodiment in that it is installed on a rock 19a having a height difference. In the jacket structure 1a of the lower structure 49a, some of the legs 3a are short in length.

The substructure 49a is constructed in the same procedure as the substructure 49 of the first embodiment. When constructing the jacket structure 1a on land, the length of the legs 3 and 3a is determined in consideration of the height difference of the bedrock 19a.

In the second embodiment, by using the jacket structure 1a having a plurality of legs with different lengths, the lower structure can be easily constructed even when there is a height difference in the bedrock on the bottom of the water.

A third embodiment will be described. FIG. 7 is a diagram showing substructures 49b, 49c according to a third embodiment of the invention.

The lower structure 49b shown in FIG. 7(a) is mainly different from the lower structure 49 of the first embodiment in that ground anchors 25a are provided outside the leg 3 in addition to the ground anchors 25 inside the leg 3. .

A fixing plate 23a having a guide hole 24a is fixed to the outer periphery of the leg 3 in the lower structure 49b. Further, the sheath tube 17a is fixed to the bottom plate 5. As shown in FIG. The sleeve tube 17a is arranged at a position corresponding to the guide hole 24a when viewed from the axial direction of the leg 3 .

The substructure 49b is constructed in the same procedure as the substructure 49 of the first embodiment. The ground anchor 25a is drilled and driven in the bedrock 19 using the guide hole 24a and the sheath tube 17a as guides, before and after the ground anchor 25. As shown in FIG. The lower end of the ground anchor 25a is fixed to the bedrock 19 by the anchor body 27a, and the upper end is fixed to the fixing plate 23a by the fixing member 33a.

The lower structure 49c shown in FIG. 7B is mainly different from the lower structure 49 of the first embodiment in that no ground anchor is provided inside the leg 3, and the ground anchor 25a is provided only on the outer side of the leg 3. different.

The substructures 49b, 49c of the third embodiment are expected to exert a large pull-out force on the jacket structures 1b, 1c, and the required number of ground anchors cannot be placed inside the leg 3, for example. effective for If a sheath pipe (not shown) is provided between the guide hole 24a and the sheath pipe 17a in the lower structures 49b and 49c, the ground anchor 25a can be protected from corrosion by seawater and damage by drifting objects.

A fourth embodiment will be described. FIG. 8 shows a lower structure 49d according to a fourth embodiment of the invention.

The substructure 49d is mainly different from the substructure 49 of the first embodiment in that the ground anchors 25b are provided in the space surrounded by the leg 3 and the connecting member 7. As shown in FIG.

In the lower structure 49 d , a fixing plate 37 is fixed inside the connection member 35 connected to the wind turbine tower, which is joined onto the jacket structure 1 d of the lower structure 49 . The fixing plate 37 has a guide hole 24b.

In order to construct the lower structure 49d, the jacket structure 1d is constructed on land and submerged on the bedrock 19 in the same manner as in the first embodiment. Next, the connection member 35 is joined onto the jacket structure 1d. Then, the rock 19 is drilled using the guide hole 24b as a guide, and the ground anchor 25b is driven. The lower end of the ground anchor 25b is fixed to the bedrock 19 by the anchor body 27b, and the upper end is fixed to the fixing plate 37 by the fixing member 33b.

The lower structure 49d of the fourth embodiment is also effective when a large pullout force is assumed to act on the jacket structure 1d and the required number of ground anchors cannot be arranged inside the leg 3 29. . Since the ground anchor 25b is arranged in the space surrounded by the leg 3 and the connecting member 7, it can be protected from damage caused by drifting objects.

The configuration of the bottom plate 5 is not limited to those shown in the first to fourth embodiments. FIG. 9 is a diagram showing another example of bottom plates 5a and 5b.

The bottom plate 5a shown in FIG. 9(a) is a single steel plate having a predetermined thickness. The bottom plate 5a has a guide hole 39 penetrating from the upper surface to the lower surface instead of the sheath tube. When the bottom slab 5a is used, the ground anchor is driven by drilling the bedrock using the guide hole 39 as a guide.

The bottom plate 5b shown in FIG. 9(b) is a single steel plate having a predetermined thickness. The bottom plate 5b has a hole 41 having substantially the same diameter as the inside 29 of the leg 3, and guide plates 43 larger than the hole 41 are fixed to the upper and lower surfaces of the bottom plate 5b. The guide plate 43 has a guide hole 39a. When the bottom plate 5b is used, the ground anchor is driven by drilling the bedrock using the guide hole 39a as a guide.

A fifth embodiment will be described. 10 to 12 are diagrams showing the steps of constructing the lower structure 49e.

The substructure 49e shown in FIG. 12 is mainly different from the substructure 49 of the first embodiment in that the supporting portion of the leg 3 is the foot protection concrete 53. As shown in FIG. In the lower structure 49e, the lower end of the leg 3 is supported by the foot protection concrete 53 placed on the bedrock 19 of the water bottom.

In the process shown in FIG. 10(a), an excavation portion 51 is formed in the bedrock 19 at the bottom of the water. The excavation section 51 is formed to have a predetermined size by connecting a plurality of cylindrical spaces excavated using a full swing excavator (not shown). Around the time when the excavation section 51 is formed, the jacket structure 1e is constructed on land.

In the process shown in FIG. 10(b), the jacket structure 1e is transported to the site by a hoist ship, set down on the bedrock 19 at the bottom of the water, and the lower end of the leg 3 is inserted into the excavation section 51. In the process shown in FIG. In the process shown in FIG. 11, the excavated portion 51 is filled with concrete to form foot protection concrete 53 . The embedding depth of the leg 3 into the foot protection concrete 53 is equal to or greater than the diameter of the leg 3, and is determined so as to secure the embedding depth necessary for the vertical bearing capacity of the leg 3.

In the process shown in FIG. 12, a drilling machine (not shown) installed in the sea portion of the jacket structure 1e is used to drill a hole in the rock 19 from the inside 29 of the leg 3 . During drilling, the guide hole 24 of the fixing plate 23 is used as a guide. A ground anchor 25 is driven through the leg 3 , and the lower end of the ground anchor 25 is fixed to the bedrock 19 by the anchor body 27 . The upper end of the ground anchor 25 is fixed to the fixing plate 23 formed on the water surface by the fixing tool 33 . Thus, the ground anchor 25 passing through the inside 29 of the leg 3 fixes the jacket structure 1e to the bedrock 19 of the water bottom. After that, filling sand 31 is filled into the inside 29 of the leg 3 using a filling hole (not shown) provided in the fixing plate 23 to complete the lower structure 49e of the foundation for offshore wind power generation.

In the fifth embodiment, after inserting the lower end of the leg 3 into an excavated portion 51 excavated in the rock 19 , concrete is filled to form foot protection concrete 53 that supports the leg 3 . Therefore, the lower structure 49e can be easily constructed even when the bedrock 19 at the bottom of the water is uneven or inclined.

In the lower structure 49e, since the foot protection concrete 53 and the ground anchor 25, which are the supporting portions of the leg 3, are used together, the pressing force from the jacket structure 1e is transmitted to the bedrock 19 by the foot protection concrete 53, and the pull-out force is transferred to the bedrock 19 by the foot protection concrete 53. The ground anchor 25 allows for a resistive structure. Therefore, the jacket structure 1e can be fixed to the bottom of the water without driving piles.

In the lower structure 49e, since the ground anchor 25 is arranged through the inside 29 of the leg 3, the ground anchor 25 can be protected from corrosion by sea water, damage by drifting objects, and the like. In addition, since the other end of the ground anchor 25 is fixed to the fixing portion formed in the above-water portion of the leg 3, diver work in water is not required when constructing the ground anchor 25. - 特許庁Furthermore, by filling the leg 3 with filling sand 31, the weight of the jacket structure 1e can be appropriately adjusted.

When the legs 3 of the jacket structure 1e are arranged in the previously formed excavation portion 51 as in the fifth embodiment, or when the jacket structure is arranged on the previously formed pile foundation, the jacket structure 1 is It must be set with precision. On the other hand, when the jacket structure is lowered with the bottom plate 5 attached to the leg 3 as in the first to fourth embodiments, the allowable range of error in the lowered position can be increased.

In the first to fifth embodiments, the filling sand 31 is used as the filling material filled inside the leg, but the filling material is not limited to sand. For example, the filling material may be fluidized soil using earth and sand material generated on-site by drilling the seabed ground such as the bedrock 19 .

In the first to fifth embodiments, the leg 3 is filled with the filling sand 31 after the ground anchor 25 is driven to fix the jacket structure to the bedrock of the water bottom. After filling, the ground anchor 25 may be driven to fix the jacket structure to the bedrock. In this case, it is desirable to previously arrange a sheath tube extending from the guide hole 24 to the sheath tube 17 in order to arrange the ground anchor 25 inside the leg 3, and to fill the outside of the sheath tube with the filling sand 31.

In the first to fifth embodiments, the tension of the ground anchor may be measured while the offshore wind turbine is in service. FIG. 13 is a diagram showing an example in which an optical fiber sensor 45 is incorporated into the ground anchor 25 inside the leg 3. As shown in FIG. In the example shown in FIG. 13, an optical fiber sensor 45 for measuring tension is incorporated in the strand of the ground anchor 25 and the optical fiber sensor 45 is connected to the controller 47 . If the tension measurement value is transmitted by the control device when the offshore wind turbine is in service, it is possible to remotely manage the malfunction of the ground anchor and ensure the safety of the substructure. Measurement of the tension is not limited to the optical fiber sensor, and may be performed by a sensor using magnetism.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope of the technical ideas disclosed in the present application, and these naturally belong to the technical scope of the present invention. Understood.

1, 1a, 1b, 1c, 1d, 1e --- Jacket structure 3, 3a --- Legs 5, 5a, 5b --- Bottom plate 7 --- Connecting member 9 --- Top plate 11 --- Bottom surface Plate 13 Vertical rib material 15 Rib material 17, 17a Sheath tube 19, 19a Bedrock 21 Water surface 23, 23a, 37 Fixing plate 24, 39, 39a ……Guide holes 25, 25a, 25b……Ground anchors 27, 27a, 27b……Anchor body 29……Inside 31……Filling sand 33, 33a, 33b……Fixer 35………… Connection member 41 Hole 43 Guide plate 45 Optical fiber sensor 47 Control device 49, 49a, 49b, 49c, 49d Substructure 51 Excavation section 53 Foot protection concrete

Claims (12)

A substructure of a foundation for offshore wind power generation, comprising:
a plurality of legs formed of hollow steel pipes;
a connecting member that connects the plurality of legs;
Equipped with a jacket structure consisting of
the lower end of the leg is supported by a support installed on the submerged ground;
one end of the jacket structure is anchored in the underwater ground, and the other end is fixed to the underwater ground by a ground anchor anchored to an anchoring portion formed on the water surface ;
A substructure for a foundation for offshore wind power generation, wherein the ground anchor is disposed through the support . the fixing portion is formed using a fixing plate fixed to the above-water portion of the leg, the fixing plate having a guide hole;
The support portion is a bottom slab installed on the water bottom ground, and the bottom slab has a sheath pipe arranged at a position corresponding to the guide hole when viewed from the axial direction of the leg,
2. The substructure of a foundation for offshore wind power generation according to claim 1 , wherein said ground anchor is arranged through said guide hole and said sheath pipe . The substructure of an offshore wind power generation foundation according to claim 1 or 2, wherein the ground anchor is arranged through the inside of the leg. A substructure of a foundation for offshore wind power generation, comprising:
a plurality of legs formed of hollow steel pipes;
a connecting member that connects the plurality of legs;
Equipped with a jacket structure consisting of
the lower end of the leg is supported by a support installed on the submerged ground;
wherein the jacket structure is fixed to the seabed by a ground anchor anchored at one end in the seabed ;
A substructure for a foundation for offshore wind power generation, wherein the ground anchor is arranged in a space surrounded by the leg and the connecting member . The offshore wind power generation foundation according to any one of claims 1 to 4 , wherein a plurality of the ground anchors are provided, and the plurality of ground anchors are anchored at different depths in the underwater ground. substructure. 6. The lower structure of an offshore wind power generation foundation according to any one of claims 1 to 5 , wherein the inside of the leg is filled with a filling material. 3. The substructure of a foundation for offshore wind power generation according to claim 2 , wherein an internal corner formed by the upper surface of said bottom slab and the outer peripheral surface of said leg is reinforced with a rib material. 8. The lower part of the foundation for offshore wind power generation according to claim 2 or 7, wherein the bottom plate comprises an upper plate, a lower plate, and vertical rib members connecting the upper plate and the lower plate. structure. 5. The lower structure of the foundation for offshore wind power generation according to claim 1 , wherein the support portion is a foot protection concrete for the leg formed by excavating the submerged ground. A method for constructing a substructure of a foundation for offshore wind power generation, comprising:
Step a of constructing a jacket structure having a plurality of legs formed of hollow steel pipes;
a step (b) of transporting the jacket structure to the site and supporting the lower ends of the legs with a support installed on the submerged ground;
a step c of fixing the jacket structure to the submerged ground by means of ground anchors penetrating the support portion ;
and
A method of constructing a substructure of a foundation for offshore wind power generation, wherein in the step c, one end of the ground anchor is anchored in the underwater ground, and the other end is anchored to an anchoring portion formed on the water surface. . the fixing portion is formed using a fixing plate fixed to the above-water portion of the leg, the fixing plate having a guide hole;
The support portion is a bottom plate that supports the leg, and the bottom plate has a sheath pipe arranged at a position corresponding to the guide hole when viewed from the axial direction of the leg,
In the step a, attaching the bottom plate to the lower end of the leg,
In the step b, placing the bottom plate on the water bottom ground,
In the step (c), using the guide hole and the sheath pipe as a guide, the ground anchor is drilled in the seabed ground, the ground anchor is arranged , and the other end of the ground anchor is fixed to the fixing plate . Item 11. A method for constructing a substructure of a foundation for offshore wind power generation according to Item 10. A method for constructing a substructure of a foundation for offshore wind power generation, comprising:
Step a of constructing a jacket structure having a plurality of legs formed of hollow steel pipes and connecting members connecting the plurality of legs ;
a step (b) of transporting the jacket structure to the site and supporting the lower ends of the legs with a support installed on the submerged ground;
a step c of fixing the jacket structure to the submerged ground by a ground anchor arranged in a space surrounded by the legs and the connecting members ;
and
A method of constructing a substructure of a foundation for offshore wind power generation, wherein in the step c, one end of the ground anchor is anchored in the submerged ground.

Images