Seismic control structure for tower-like structure and method for constructing tower-like structure with seismic control structure

Abstract

To provide a vibration control structure of a tower-like structure capable of improving the overall vibration damping properties of a tower-like structure such as offshore wind power generation equipment while reducing the load to a cylindrical foundation as the basis of offshore wind power generation equipment, etc. due to earthquake motion, etc., and a construction method of a tower-like structure with a vibration control structure.SOLUTION: In a vibration control structure of a tower-like structure 7, a gap for isolation 13 is formed between the inner peripheral surface of an isolation hole 12, through which the cylindrical foundation 4 formed in the center of the mound 10 passes and the outer surface of cylindrical foundation 4, and between the inner peripheral surface of the through hole 18 and the outer peripheral surface of the cylindrical foundation 4, a small vibration absorption gap 19 is formed, and a vibration-damping weight body 11 is slidably placed on the mound 10.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a seismic control structure for a tower-like structure such as an offshore wind power generation device, and a method for constructing a tower-like structure with a seismic control structure. [Background technology]

[0002] One type of offshore wind power generation facility is known to have a monopile foundation consisting of a foundation tubular body inserted into the seabed, and a tower body with its lower end supported by the foundation tubular body, with a wind power generation device consisting of a wind turbine (nacelle and rotor) etc. supported on the upper end of the tower body (see, for example, Patent Document 1).

[0003] In Japan, where earthquakes are frequent, offshore wind power generation facilities with a power supply capacity of 10MW or more are subject to significant seismic motions on the monopile foundations that form the base of the facilities. Particularly when installed in deep waters, seismic motions can cause significant deformation of the monopile foundations, so the design of this type of tower-like structure is carried out with strict rigor.

[0004] In other words, in this type of tower-like structure, the lower part penetrates and is supported by the ground, and large bending moments and shear forces act on it during earthquakes, etc., so in order to ensure safety, it is necessary to increase the outer diameter and thickness of the monopile, which forms the foundation of the tower-like structure, in advance so that it can withstand these bending moments and shear forces. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-37397 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the above-described conventional technology, there is a problem that as the outer diameter and thickness of the monopile, which is the foundation of the tower-like structure, increase, the manufacturing costs of the monopile and the construction costs thereof increase.

[0007] Furthermore, as monopiles become larger, it becomes necessary to use special work vessels to handle and install the monopiles, and installing them takes time, which leads to problems such as increased costs, longer construction periods, and increased safety risks in constructing monopile foundations.

[0008] Therefore, in order to reduce the increased costs, longer construction periods, and safety risks associated with larger monopiles when constructing monopile foundations, it is desirable to reduce the burden on tower structures caused by earthquake motions, etc., and to reduce the outer diameter and thickness of the monopiles.

[0009] In view of the above-mentioned conventional problems, the present invention has been made with the aim of providing a seismic control structure for a tower-like structure and a method for constructing a tower-like structure with a seismic control structure, which can improve the seismic control performance of the entire tower-like structure, such as an offshore wind power generation facility, and reduce the load on the foundation cylindrical bodies, such as the monopile foundations of the offshore wind power generation facility, due to earthquake motion, etc. [Means for solving the problem]

[0010] The feature of the invention described in claim 1 for solving the above-mentioned conventional problems is that in a seismic control structure for a tower-shaped structure having a foundation cylindrical body that is inserted into the ground and erected on the ground, the structure comprises a mound formed on the ground around the foundation cylindrical body, and a seismic control weight body having a through hole in its center through which the foundation cylindrical body passes, wherein an edge-cutting gap is formed between the inner surface of the edge-cutting hole formed in the center of the mound and the outer surface of the foundation cylindrical body, a small vibration absorbing gap is formed between the inner surface of the through hole and the outer surface of the foundation cylindrical body, and the seismic control weight body is slidably placed on the mound.

[0011] The invention as set forth in claim 2 is characterized in that, in addition to the configuration of claim 1, the vibration-damping weight body is formed in the shape of a truncated cone cylinder having a tapered portion on the outer circumferential surface.

[0012] The feature of the invention described in claim 3 is that, in addition to the configuration of claim 1 or 2, a buffer body is provided on the inner surface of the through hole and / or the outer surface of the foundation cylindrical body facing the inner surface of the through hole.

[0013] The invention as set forth in claim 4 is characterized in that, in addition to the configuration of claim 1 or 2, the small vibration absorbing gap is filled with a stress transmitting member.

[0014] The invention as set forth in claim 5 is characterized in that, in addition to the configuration of claim 4, the mound has a filler material filled in the edge-cutting gap.

[0015] The invention as set forth in claim 6 is characterized in that, in addition to the configuration of claim 1 or 2, the outer periphery of the mound is surrounded by a steel frame body that also serves as a formwork.

[0016] The invention as set forth in claim 7 is characterized in that, in addition to the configuration of claim 3, the outer periphery of the mound is surrounded by a steel frame body that also serves as a formwork.

[0017] The invention as set forth in claim 8 is characterized in that, in addition to the configuration of claim 4, the outer periphery of the mound is surrounded by a steel frame body that also serves as a formwork.

[0018] The invention as set forth in claim 9 is characterized in that, in addition to the configuration of claim 5, the outer periphery of the mound is surrounded by a steel frame body that also serves as a formwork.

[0019] The invention described in claim 10 is characterized in that, in a method for constructing a tower-like structure with a seismic control structure having a foundation cylindrical body that is erected on the ground in a state where it is penetrated into the ground, the method includes the steps of erecting the foundation cylindrical body on the ground in a state where it is penetrated into the ground, placing a cylindrical edge-cutting hole forming formwork on the ground outside the foundation cylindrical body with a gap between the inner peripheral surface of the edge-cutting hole forming formwork and the outer peripheral surface of the foundation cylindrical body, and placing a mound forming formwork on the ground outside the edge-cutting hole forming formwork. the step of filling the mound forming formwork with mound materials to form a mound on the ground surrounding the foundation cylindrical body, the mound having an edge separation gap between the inner surface of the edge separation hole through which the foundation cylindrical body passes and the outer surface of the foundation cylindrical body; and the step of placing a vibration-damping weight body having a through hole in its center on the mound with a small vibration-absorbing gap between the inner surface of the through hole and the outer surface of the foundation cylindrical body, the vibration-damping weight body being placed slidably on the mound.

[0020] The feature of the invention described in claim 11 is that, in addition to the configuration of claim 10, a formwork unit is formed by integrating the formwork for forming the edge cutting hole and the formwork for forming the mound.

[0021] The invention described in claim 12 is characterized in that, in addition to the configuration of claim 10, it includes a step of filling the small vibration absorbing gap with a stress transmission member after placing the vibration damping weight on the mound.

[0022] The invention described in claim 13 is characterized in that, in addition to the configuration of claim 11, it includes a step of filling the small vibration absorbing gap with a stress transmission member after placing the vibration damping weight on the mound.

[0023] The invention described in claim 14 is characterized in that, in addition to the configuration of claim 12 or 13, it includes a step of filling the edge-cutting gap with a filler after forming the mound. [Effects of the Invention]

[0024] The vibration control structure for a tower-like structure according to the present invention, having the configuration described in claim 1, is not affected by small vibrations that occur on a daily basis, and when a large external force such as an extremely rare earthquake acts on it, the vibration control weight body slides on the mound, converting the energy of the seismic motion into thermal energy through friction and absorbing it, thereby reducing the load on the entire tower-like structure. Furthermore, by reducing the load on the entire tower-like structure, the cross-sectional force acting on the tower-like structure during an earthquake can be reduced, and accordingly the outer diameter and wall thickness of the foundation cylindrical body such as a monopile can be reduced.

[0025] Furthermore, in the present invention, by providing the configuration described in claim 2, when a certain thickness (height) is ensured so that the energy from seismic motion can be efficiently converted into thermal energy through friction and absorbed, the seismic damping weight body is made into a truncated cone cylindrical shape, which stabilizes the seismic damping weight body, prevents it from floating up or tipping over, and makes it easier for it to slide on the mound.

[0026] Furthermore, in the present invention, by providing the configuration described in claim 3, the buffer body can absorb small vibrations that occur on a daily basis, and also soften the impact caused by sliding between the tower-like structure and the seismic damping weight body when a large external force such as an extremely rare earthquake acts, thereby preventing damage to the tower-like structure and the seismic damping weight body.

[0027] Furthermore, in the present invention, by providing the configuration described in claim 4, the seismic control weight body and the foundation cylindrical body can be integrated, and the load caused by earthquake motion, etc. can be distributed or absorbed by the seismic control structure.

[0028] Furthermore, in the present invention, by adopting the configuration described in claim 5, the foundation cylindrical body and the seismic damping weight body can be prevented from becoming integrated with the mound, and the sliding of the seismic damping weight body can be prevented from being hindered when a large external force such as an extremely rare earthquake acts on it.

[0029] Furthermore, in the present invention, by incorporating the configurations described in claims 6 to 9, the process of removing the formwork can be omitted, shortening the construction period, and the mound can be structurally reinforced.

[0030] Furthermore, in the present invention, by incorporating the configurations described in claims 10 and 11, it is possible to efficiently construct a tower-like structure with a seismic control structure in which the seismic energy generated by the earthquake can be converted into frictional force and absorbed by the seismic energy generated by the earthquake, thereby reducing the burden on the foundation cylindrical body.

[0031] Furthermore, in the present invention, by providing the configurations described in claims 12 and 13, the gap between the foundation cylindrical body and the seismic damping weight body can be filled, and the foundation cylindrical body and the seismic damping weight body can be integrated, so that the stress acting on the foundation cylindrical body due to small vibrations that occur on a daily basis or small-scale seismic motion can be dispersed or absorbed by the seismic damping weight body.

[0032] Furthermore, in the present invention, by providing the configuration described in claim 14, it is possible to prevent the mound and the seismic damping weight body from being integrated together. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a front view showing an embodiment of a vibration control structure for a tower-like structure according to the present invention. [Figure 2] FIG. 2 is a partially enlarged cross-sectional view showing the vibration control structure portion of the same. [Figure 3] FIG. [Figure 4] FIG. 4 is a partially enlarged cross-sectional view showing another example of the vibration control structure portion of the same. [Figure 5] FIG. 10 is a partially enlarged cross-sectional view showing yet another example of the vibration control structure portion of the same. [Figure 6] FIG. 10 is a partially enlarged cross-sectional view showing the foundation cylindrical body erection step of the method for constructing a tower-like structure with a seismic control structure according to the present invention. [Figure 7] FIG. 4 is a partially enlarged cross-sectional view showing the formwork installation step of the same. [Figure 8] FIG. 10 is a partially enlarged cross-sectional view showing the mound forming step of the embodiment; [Figure 9] FIG. 10 is a partially enlarged cross-sectional view showing the state of the seismic damping weight body installation step of the embodiment; [Figure 10] FIG. 10 is a partially enlarged cross-sectional view showing a state of the stress transmission member filling step of the embodiment; [Figure 11] 11A and 11B are plan views of FIG. 10, in which (a) shows a state in which the position of the seismic damping weight body is eccentric with respect to the mound, and (b) shows a state after the stress transmission members have been filled. [Figure 12] FIG. 1 is a diagram for explaining the action of the vibration control structure for a tower-like structure according to the present invention, and is a partially enlarged cross-sectional view of a portion of the vibration control structure when subjected to everyday external forces. [Figure 13] This is an enlarged cross-sectional view of the seismic control structure portion when subjected to a large external force such as an extremely rare earthquake motion. DETAILED DESCRIPTION OF THE INVENTION

[0034] Next, an embodiment of the seismic control structure for a tower-like structure according to the present invention will be described based on the examples shown in Figures 1 to 5. In the figures, reference numeral 1 denotes the ground such as bedrock, and reference numeral 2 denotes the water surface. In this example, a monopile-type offshore wind power generation facility 3 will be used as an example of the tower-like structure.

[0035] As shown in Figure 1, the offshore wind power generation facility 3 comprises a foundation tubular body 4 (monopile foundation) that is inserted into the waterbed 1 and erected on the waterbed 1, a hollow cylindrical tower body 5 supported by the foundation tubular body 4, and a wind turbine facility 6 (nacelle / rotor) supported on the upper end of the tower body 5, with the foundation tubular body 4 and tower body 5 forming a tower shape.

[0036] The foundation cylindrical body 4 is made of a steel pipe or the like and is formed into a cylindrical shape with open upper and lower ends. Note that the form of the foundation cylindrical body 4 is not limited to a cylindrical shape and may be, for example, a polygonal cylindrical shape.

[0037] As shown in Figures 1 and 2, this foundation tubular body 4 is cast with its lower side penetrating the waterbed 1 to a predetermined depth and its upper side protruding a predetermined height above the water surface 2. The ground 1 is a solid foundation such as bedrock that will not sink even if a heavy object is placed on it.

[0038] This tower-like structure is also equipped with a vibration control structure 7, which reduces the burden of external forces such as earthquakes.

[0039] This seismic control structure 7 comprises a mound 10 formed on the ground 1 around a tower-shaped structure (foundation cylindrical body 4), and a seismic control weight body 11 placed slidably on the mound 10.The seismic control weight body 11 comes into contact with the tower-shaped structure (foundation cylindrical body 4) and slides on the mound 10, thereby converting external forces caused by earthquake motion, etc. into thermal energy of friction generated between the mound 10 and the seismic control weight body 11 and absorbing it, thereby reducing the burden on the foundation cylindrical body 4.

[0040] As shown in FIG. 2, the mound 10 is made of a mound material such as underwater concrete and has a rectangular shape with a flat upper surface and a certain thickness, and is firmly fixed onto the waterbed 1 .

[0041] This mound 10 has a cut-off hole 12 that penetrates through the thickness direction in the center, and the tower-like structure (foundation cylindrical body 4) penetrates through the cut-off hole 12 into the mound 10, which is formed on the ground 1 around the foundation cylindrical body 4 that constitutes the tower-like structure.

[0042] The edge cutting hole 12 is formed with an inner diameter larger than the outer diameter of the tower-like structure (foundation cylindrical body 4), and an edge cutting gap 13 of a constant width is formed around the entire circumference between the inner surface of the edge cutting hole 12 and the outer surface of the tower-like structure (foundation cylindrical body 4).

[0043] As shown in FIG. 5, the edge separation gap 13 may be filled with a filler 14 having a certain degree of fluidity, such as sand, if necessary.

[0044] The outer periphery of this mound 10 is surrounded by a steel frame that also serves as a formwork used when forming the mound 10 (hereinafter referred to as a mound formation formwork 15), thereby providing structural reinforcement. In the drawing, reference numeral 16 denotes a formwork for forming edge cut holes.

[0045] The seismic damping weight body 11 is made of concrete and formed into a truncated cone shape with a tapered portion 17 on the outer periphery, and has a stable shape with a constant contact surface on the underside with the mound 10. Note that the form of the seismic damping weight body 11 is not limited to a truncated cone shape, and may be, for example, a cylindrical shape, a rectangular frame shape, a polygonal frame shape, or the like.

[0046] This seismic damping weight body 11 has a through-hole 18 in the center, and is placed on the mound 10 with the tower-like structure (foundation cylindrical body 4) passing through the through-hole 18.

[0047] The through hole 18 is slightly larger than the outer diameter of the tower-like structure (foundation cylindrical body 4), and a small vibration absorbing gap 19 of a constant width is formed around the entire circumference between the inner surface of the through hole 18 and the outer surface of the tower-like structure (foundation cylindrical body 4).

[0048] The through-hole 18 may be formed slightly larger than the outer diameter of the tower-like structure (foundation cylindrical body 4), and a buffer body 20 made of rubber or the like may be provided on the inside (inner peripheral surface) of the through-hole 18, so that the stress acting on the foundation cylindrical body 4 due to everyday vibrations, small-scale earthquake motions, etc. is dispersed or absorbed by the seismic control weight body 11. The buffer body 20 may be provided on the outer peripheral surface of the foundation cylindrical body 4 facing the through-hole 18, or may be provided on both the outer peripheral surface of the foundation cylindrical body 4 and the inside of the through-hole 18.

[0049] Furthermore, the buffer 20 has additional effects other than the buffer effect that vary depending on the strength.

[0050] For example, if a low-strength material such as a sponge is used, small vibrations that act on a daily basis will not be transmitted to the seismic damping weight body 11, similar to the effect of the small vibration absorbing gap 19 described below, and the tower-like structure and the seismic damping weight body 11 will come into contact only when a large external force acts due to extremely rare seismic activity, etc., and if a high-strength material such as rubber is used, the stress acting on the foundation cylindrical body 4 will be transmitted to the seismic damping weight body 11, and the stress can be dispersed or absorbed (energy consumption) by the seismic damping weight body 11.

[0051] These small vibration absorbing gaps 19 are formed at intervals of about 1 cm to 3 cm in the 8.5 m diameter cylindrical foundation body 4, so that small vibrations acting on a daily basis are not transmitted to the seismic damping weight body 11, and the tower-like structure and the seismic damping weight body 11 come into contact and slide on the mound 10 only when a large external force is applied due to an extremely rare earthquake motion or the like. The small vibration absorbing gaps 19 are smaller than the separation gaps 13, so that when the tower-like structure (cylindrical foundation body 4) sways due to a large external force such as an extremely rare earthquake motion, the tower-like structure (cylindrical foundation body 4) always comes into contact with the seismic damping weight body 11 before the mound 10. The gap width of the small vibration absorbing gaps 19 is set taking into consideration the size of the cylindrical foundation body 4, the amount of displacement due to load, and the amount of normal displacement.

[0052] 4, although not necessarily required from the structural standpoint, the small vibration absorbing gap 19 may be filled with a stress transmission member 21 made of grout or the like to integrate the tower-like structure (cylindrical foundation body 4) and the seismic damping weight body 11. Incidentally, the small vibration absorbing gap 19 may contain both a buffer material 20 and a stress transmission member 21.

[0053] Next, a method for constructing this tower-type structure with a seismic control structure will be described with reference to Figures 6 to 11. Note that the same components as those in the above-described embodiment will be given the same reference numerals and the description thereof will be omitted.

[0054] First, the foundation cylindrical body 4 is inserted into the ground 1 and erected according to an existing construction method.

[0055] Specifically, although not specifically shown, first, a foundation cylindrical body 4 such as a monopile manufactured in a factory or manufacturing yard on land is transported to a base port, and then loaded onto a lifting work vessel (hereinafter referred to as an SEP vessel) using the SEP vessel's crane at the base port.

[0056] Next, the SEP vessel loaded with the foundation cylindrical body 4 is transported by sea to the installation area, and then the legs of the SEP vessel are lowered and landed on the seabed at the installation area, and the SEP vessel body supported by the legs is raised above the water, making the SEP vessel body stable against waves, etc.

[0057] Next, the foundation cylindrical body 4 loaded on the SEP vessel is lifted up and erected using the crane of the SEP vessel, and then lowered in this state to the water bottom ground 1 and allowed to settle on the bottom.

[0058] Then, the head of the foundation cylindrical body 4 that has been placed on the waterbed 1 is driven in with a hammer or the like, so that the foundation cylindrical body 4 penetrates the waterbed 1 and is installed as shown in Figure 6 (foundation cylindrical body erection process).

[0059] Next, as shown in Figure 7, a cylindrical formwork 16 for forming edge cut holes is placed on the bottom ground 1 at a predetermined distance from the outer surface of the foundation cylindrical body 4, and a formwork 15 for forming mounds is placed on the ground 1 outside the formwork 16 for forming edge cut holes (formwork installation process).

[0060] The formwork 16 for forming the edge cutting hole is made of a steel pipe or the like having an inner diameter larger than the outer diameter of the foundation cylindrical body 4 to match the shape of the edge cutting hole 12, and is suspended from above the foundation cylindrical body 4 in a concentric arrangement to the outside of the foundation cylindrical body 4.

[0061] As shown in Figure 3, the mound formation formwork 15 is composed of formwork plates 15a, 15a... arranged on all four sides to match the outer periphery of the mound 10 to be formed, and the side edges of adjacent formwork plates 15a, 15a... in the circumferential direction are joined together to form a rectangular frame.

[0062] It is desirable that the edge cutting hole forming formwork 16 and the mound forming formwork 15 be fabricated as an integrated formwork unit 22 in a fabrication yard on the ground or on a work barge.

[0063] 7 and 8, this formwork unit 22 has an edge cutting hole forming formwork 16 placed in the center, and the edge cutting hole forming formwork 16 is supported inside the mound forming formwork 15 via support members 23, 23.... Note that reinforced concrete wall material (RC wall material) may also be used as the mound forming formwork 15.

[0064] The formwork unit 22 is then transported to the construction waters by a barge or the like, and as shown in Figure 7, the formwork unit 22 is hoisted up by a crane and its position is adjusted above the foundation cylinder 4 so that the edge cutting hole forming formwork 16 and the foundation cylinder 4 are concentrically arranged, and after adjusting the horizontal (rotational) position of the mound forming formwork 15, the formwork unit 22 is lowered in that position until it hits the bottom of the water 1. Note that the reference numeral 24 in the figure denotes a hoisting wire.

[0065] Then, if necessary, the position of the formwork unit 22 is finally adjusted; specifically, the position is adjusted so that a predetermined gap is created around the entire circumference between the inner circumference of the formwork 16 for forming the edge cutting hole and the outer circumference of the foundation cylindrical body 4, and the formwork 16 for forming the edge cutting hole and the formwork 15 for forming the mound are placed on the bottom ground 1.

[0066] Next, as shown in Figure 8, underwater concrete 10a is poured as mound material between the edge cutting hole forming formwork 16 and the mound forming formwork 15 through a concrete pouring pipe 26 from a work boat 25 on the water, forming a mound 10 on the waterbed ground 1 around the foundation cylindrical body 4 (mound formation process).

[0067] At this time, the bottom surface of the mound formation formwork 15 is in an open state, and the poured underwater concrete 10a is poured directly onto the top surface of the waterbed ground 1, so that as the underwater concrete 10a hardens, the mound 10 is firmly fixed to the waterbed ground 1, which is a bedrock or other ground.

[0068] In the mound formation process, once the concrete has been poured up to the top surface of the mound formation formwork 15, the top surface of the underwater concrete 10a is leveled as necessary before it hardens to form a flat surface on the top surface of the mound 10.

[0069] In the mound 10 constructed in this manner, the inner diameter of the formwork 16 for forming the edge cutting hole is larger than the outer diameter of the foundation cylindrical body 4, so an edge cutting hole 12 is formed in the center through which the foundation cylindrical body 4 passes, and an edge cutting gap 13 is formed between the inner surface of the edge cutting hole 12 and the outer surface of the foundation cylindrical body 4.

[0070] Next, once the mound 10 has been formed, as shown in Figure 9, the seismic damping weight body 11 is moved above the foundation cylindrical body 4 using a crane, and its position is adjusted so that the through hole 18 formed in the center of the seismic damping weight body 11 and the foundation cylindrical body 4 are concentrically arranged.The seismic damping weight body 11 is then lowered at that position and placed on the mound 10.

[0071] In this case, since the inner diameter of the through hole 18 is larger than the outer diameter of the foundation cylindrical body 4, a small vibration absorbing gap 19 is formed between the inner peripheral surface of the through hole 18 and the outer peripheral surface of the foundation cylindrical body 4. It is also possible to arrange a buffer material 20 made of a sponge material, rubber material, or the like on the inner peripheral surface of the through hole 18 of the seismic damping weight body 11 in advance.

[0072] 10 and 11, if necessary, the lower end of the small vibration absorbing gap 19 is closed with a grout seal (not shown), and the small vibration absorbing gap 19 is filled with a stress transmission member 21 made of grout or the like through a grout injection pipe 28 from a work boat 27 on the water (stress transmission member filling step). At this time, it is advisable to provide a buffer 20 made of a sponge material or the like to substitute for the small vibration absorbing gap 19 between the grout seal and the seismic control weight body 11.

[0073] Furthermore, even if the seismic damping weight body 11 is placed on the mound 10 in an eccentric position relative to the foundation cylindrical body 4, as shown in Figure 11(a), by filling the small vibration absorbing gap 19 with a stress transmission member 21 as shown in Figure 11(b), the foundation cylindrical body 4 and the seismic damping weight body 11 can be integrated, and the stress acting on the foundation cylindrical body 4 can be transmitted to the seismic damping weight body 11, allowing the stress to be dispersed or absorbed (energy consumption) by the seismic damping weight body 11.

[0074] Furthermore, after the mound 10 is formed, as shown in Figure 5, if a filler 14 with a certain fluidity, such as sand, is filled into the edge separation gap 13, the filler 14 will close the bottom side of the small vibration absorption gap 19, preventing the stress transfer member 21 from flowing into the edge separation gap 13, so that the stress transfer member 21 can be filled without using a grout seal.

[0075] Then, the stress transmission members 21 are cured and solidified, whereby the seismic control structure 7 is constructed.

[0076] Incidentally, the stress transmission member 21 does not necessarily have to be provided, and if the stress transmission member 21 is not provided, after placing the seismic damping weight body 11 on the mound 10, the position is fine-tuned so that the small vibration absorbing gap 19 between the inner surface of the through hole 18 and the outer surface of the foundation cylindrical body 4 has a predetermined range width around the entire circumference (approximately 1 cm to 3 cm for a foundation cylindrical body 4 with a diameter of 8.5 m).

[0077] Next, once construction of the seismic control structure 7 is complete, the tower main body 5 with the wind turbine equipment 6 (nacelle and rotor) fixed to its upper end is transported to the construction waters, the tower main body 5 with the wind turbine equipment 6 (nacelle and rotor) fixed to its upper end is lifted using a crane ship or the like, and the lower end of the tower main body 5 is connected to the foundation cylindrical body 4, and the offshore wind power generation equipment 3 is constructed.

[0078] In the vibration control structure 7 for a tower-like structure configured in this manner, as shown in FIG. 12, even if a relatively small external force generated on a daily basis by wind, waves, etc. acts on the tower-like structure and the tower-like structure vibrates slightly, the vibration is absorbed by the small vibration absorbing gap 19 or the buffer body 20, the vibration control weight body 11 does not operate, and the tower-like structure and the vibration control weight body 11 do not affect each other.

[0079] On the other hand, when a large external force due to an extremely rare earthquake or the like acts on the tower-like structure and causes it to swing significantly, as shown in Figure 13, the outer surface of the swinging tower-like structure (foundation cylindrical body 4) presses against the inner surface of the through hole 18 of the seismic damping weight body 11, causing the seismic damping weight body 11 to slide on the mound 10.

[0080] At this time, since the width of the edge separation gap 13 is larger than the width of the small vibration absorption gap 19, the swaying tower-like structure first comes into contact with the seismic damping weight body 11 and presses against it, allowing the seismic damping weight body 11 to slide on the mound 10.

[0081] The sliding of this vibration-damping weight body 11 generates friction between the vibration-damping weight body 11 and the mound 10, and the kinetic energy due to the external force acting on the tower-like structure is converted into thermal energy due to friction and absorbed, thereby suppressing the shaking of the tower-like structure.

[0082] Therefore, a tower-like structure equipped with this seismic control structure 7 can reduce the load on the tower-like structure. Furthermore, by reducing the load on the tower-like structure, the cross-sectional force acting on the tower-like structure during an earthquake can be reduced, and the outer diameter and wall thickness of the tower-like structure can be reduced accordingly.

[0083] Furthermore, in this seismic control structure 7, the seismic control weight body 11 is made in the shape of a truncated cone, which allows the seismic control weight body 11 to slide stably on the mound 10, and the kinetic energy caused by external forces acting on the tower-like structure can be efficiently converted into thermal energy through friction and absorbed.

[0084] The higher (thicker) the vibration-damping weight body 11 is, the higher the position at which the vibration-damping cylindrical body 11 is pressed when the foundation cylindrical body 4 sways, and as a result, the sliding amount (stroke) becomes larger, and the kinetic energy due to sliding can be efficiently converted into thermal energy due to friction.

[0085] On the other hand, if the vibration-damping weight body 11 becomes taller, the center of gravity becomes higher, which may cause the body to tip over or float up. Therefore, by making the vibration-damping weight body 11 into a truncated cone cylindrical shape, the necessary weight and height are ensured while the center of gravity is lowered, preventing the body from tipping over or floating up, and allowing the body to slide stably on the mound 10.

[0086] In this embodiment, the width of the small vibration absorbing gap 19, the width of the edge separation gap 13, and the sway of the tower-like structure are exaggerated in order to explain the action of the seismic control structure 7. In reality, the width of the small vibration absorbing gap 19 is approximately 1 cm to 3 cm in a foundation cylindrical body 4 with a diameter of 8.5 m, and the width of the edge separation gap 13 and the amplitude of the sway of the tower-like structure are also consistent with this.

[0087] In the above-described embodiment, an offshore wind power generation device has been used as an example of a tower-like structure, but the present invention can also be applied to other tower-like structures, such as wind power generation devices installed on land. [Explanation of symbols]

[0088] 1 ground 2 water surface 3 Offshore wind power generation facilities 4. Foundation cylinder 5 Tower body 6 Windmill equipment 7 Seismic control structure 10 Mound 11 Seismic control weight body 12 Edge cutting hole 13 Edge cutting gap 14 Filling material 15 Mound formation formwork 16 Formwork for forming edge cut holes 17 Tapered section 18 Through holes 19 Small vibration absorption gap 20 Buffer 21 Stress transmission member 22 Formwork Unit 23 Support member 24 Suspension wire 25 Workboat 26 Concrete injection pipe 27 Workboat 28 Grout injection pipe

Claims

1. A seismic control structure for a tower-like structure having a foundation tubular body that is inserted into the ground and erected on the ground, a mound formed on the ground around the foundation cylindrical body; and a seismic damping weight body having a through-hole in the center through which the foundation cylindrical body passes, An edge separation gap is formed between the inner peripheral surface of the edge separation hole formed in the center of the mound and the outer peripheral surface of the foundation cylindrical body, A vibration-damping structure for a tower-like structure, characterized in that a small vibration-absorbing gap is formed between the inner surface of the through hole and the outer surface of the foundation cylindrical body, and the vibration-damping weight body is slidably placed on the mound.

2. 2. The vibration damping structure for a tower-like structure according to claim 1, wherein the vibration damping weight body is formed in the shape of a truncated cone having a tapered portion on the outer periphery.

3. 3. A seismic control structure for a tower-like structure as described in claim 1 or 2, wherein a buffer is provided on the inner peripheral surface of the through hole and / or on the outer peripheral surface of the foundation cylindrical body facing the inner peripheral surface of the through hole.

4. 3. A vibration control structure for a tower-like structure according to claim 1, wherein said small vibration absorbing gap is filled with a stress transmission member.

5. The seismic isolation structure for a tower-like structure according to claim 4, wherein the mound has a filler material filled in the edge isolation gap.

6. 3. The seismic isolation structure for a tower-like structure according to claim 1, wherein the mound has an outer periphery surrounded by a steel frame body that also serves as a formwork.

7. 4. The seismic isolation structure for a tower-like structure according to claim 3, wherein the outer periphery of said mound is surrounded by a steel frame body that also serves as a formwork.

8. 5. The seismic isolation structure for a tower-like structure according to claim 4, wherein the outer periphery of said mound is surrounded by a steel frame body that also serves as a formwork.

9. 6. The vibration control structure for a tower-like structure according to claim 5, wherein the outer periphery of said mound is surrounded by a steel frame body that also serves as a formwork.

10. A method for constructing a tower-like structure with a seismic control structure, the tower-like structure having a foundation cylindrical body that is inserted into the ground and erected on the ground, comprising: a step of erecting the foundation cylindrical body in the ground in a state where the foundation cylindrical body is inserted into the ground; A process of placing a cylindrical edge-cutting hole forming form on the ground outside the foundation cylindrical body with a gap between the inner surface of the edge-cutting hole forming form and the outer surface of the foundation cylindrical body, and placing a mound forming form on the ground outside the edge-cutting hole forming form; a step of filling the mound forming formwork with mound members to form a mound on the ground surrounding the foundation cylindrical body, the mound having an edge separation gap between the inner surface of the edge separation hole through which the foundation cylindrical body passes and the outer surface of the foundation cylindrical body; a step of placing a seismic damping weight having a through hole in the center on the mound with a small vibration absorbing gap provided between the inner peripheral surface of the through hole and the outer peripheral surface of the foundation cylindrical body; A method for constructing a tower-like structure with a seismic control structure, characterized in that the seismic control weight body is slidably placed on the mound.

11. 11. The method for constructing a tower-like structure with a seismic control structure according to claim 10, wherein the formwork for forming the edge cut hole and the formwork for forming the mound are integrated to form a formwork unit.

12. 11. The method for constructing a tower-like structure with a seismic structure according to claim 10, further comprising the step of filling the small vibration absorbing gap with a stress transmission member after placing the seismic damping weight on the mound.

13. 12. The method for constructing a tower-like structure with a seismic structure according to claim 11, further comprising the step of filling the small vibration absorbing gap with a stress transmission member after placing the seismic damping weight on the mound.

14. 14. The method for constructing a tower-like structure with a seismic control structure according to claim 12 or 13, further comprising the step of filling the edge separation gap with a filler after forming the mound.

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