Floating structure

Abstract

This floating structure includes: a float 130 capable of floating in a liquid 114; a plurality of gas accommodating chambers 140 provided on the lower side of the float 130 and partitioned by inner walls 134 and outer walls 132; and orifices 150 provided respectively to the gas accommodating chambers 140. The plurality of gas accommodating chambers 140 each include: at least one first gas accommodating chamber having a first volume; and a second gas accommodating chamber having a second volume smaller than the first volume.

Description

Floating structure

[0001] This disclosure relates to a floating structure. This application claims priority under Japanese Patent Application No. 2024-223957, filed on 19 December 2024, the contents of which are incorporated herein by reference.

[0002] Floating structures, which ensure seismic isolation performance by suspending the structure in a fluid, have been known for some time. It is generally known that the seismic isolation performance of such floating structures is high in the horizontal direction.

[0003] Furthermore, in order to enhance the seismic isolation performance of floating structures in the vertical direction, for example, Patent Document 1 discloses the provision of an air chamber at the bottom of a floating structure and the placement of an orifice within the air chamber. The placement of the orifice within the air chamber generates a resistance force when air passes through the orifice. This resistance force acts as a damping force in the vibration response of the floating structure due to the transmission of seismic waves. This damping force can suppress the vibration response of the floating structure due to the transmission of seismic waves.

[0004] Patent Application No. 2020-095752

[0005] However, depending on the layout and center of gravity of the floating structure, the horizontal balance of the floating structure may be disrupted, and its levelness may not be maintained.

[0006] This disclosure aims to maintain the horizontality of floating structures.

[0007] To solve the above problems, a floating structure as one aspect of the present disclosure comprises a floating body capable of floating in a liquid, a plurality of gas-containing chambers provided on the lower side of the floating body and partitioned by an inner wall and an outer wall, and an orifice provided in each of the gas-containing chambers, wherein the plurality of gas-containing chambers include at least one first gas-containing chamber having a first volume and a second gas-containing chamber having a second volume smaller than the first volume.

[0008] The multiple gas containment chambers include at least three gas containment chambers, and the three or more gas containment chambers may include at least one first gas containment chamber having a first volume and at least two of the second gas containment chambers having a second volume.

[0009] The first gas containment chamber is located in the center of the floating body, and the second gas containment chamber is located in the periphery of the floating body. The diameter of the orifice in the second gas containment chamber may be smaller than the diameter of the orifice in the first gas containment chamber.

[0010] The orifice diameter may be determined based on the frequency response function of the system when the floating body, liquid, gas in the gas containment chamber, and orifice act as a single system in response to seismic waves.

[0011] The value obtained by dividing the horizontal cross-sectional area of ​​the communication hole in the orifice provided in the first gas containment chamber by the horizontal cross-sectional area of ​​the first gas containment chamber may be greater than the value obtained by dividing the horizontal cross-sectional area of ​​the communication hole in the orifice provided in the second gas containment chamber by the horizontal cross-sectional area of ​​the second gas containment chamber.

[0012] The smaller the volume of the gas containment chamber among the three or more gas containment chambers, the smaller the diameter of the orifice provided in that gas containment chamber may be.

[0013] The multiple gas containment chambers include at least nine of the gas containment chambers, and the nine or more gas containment chambers may be arranged in a row of three or more in a first horizontal direction, and in a row of three or more in a second horizontal direction that intersects with the first horizontal direction.

[0014] The system may also include a supply device for supplying gas to each of the gas containment chambers, and a control device for controlling the amount of gas supplied to each of the gas containment chambers.

[0015] According to this disclosure, the horizontality of a floating structure can be maintained.

[0016] Figure 1 is a schematic diagram of the floating seismic isolation system according to the first embodiment. Figure 2 is a schematic diagram of the gas containment chamber according to the first embodiment. Figure 3 is a cross-sectional view taken along the line III-III shown in Figure 2. Figure 4 is a partially enlarged view of the second gas containment chamber according to the first embodiment. Figure 5 is a view of the orifice shown in Figure 4 along the V-direction arrow. Figure 6 is a schematic diagram showing an example of the size of the communication holes of the orifices provided in each gas containment chamber. Figure 7 is a graph showing the relationship between the diameter of the communication holes of the orifice and the cross-sectional area of ​​the XY section of the gas containment chamber. Figure 8 is a schematic diagram of the gas containment chamber according to the second embodiment. Figure 9 is a cross-sectional view taken along the line IX-IX shown in Figure 8. Figure 10 is a schematic diagram of the gas containment chamber according to the third embodiment. Figure 11 is a cross-sectional view taken along the line XI-XI shown in Figure 10.

[0017] Embodiments of this disclosure will be described in detail below with reference to the attached drawings. The dimensions, materials, and other specific numerical values ​​shown in the embodiments are merely examples for the purpose of facilitating understanding and do not limit this disclosure unless otherwise specified. In this specification and in the drawings, elements having substantially the same function or configuration are denoted by the same reference numerals to avoid redundant explanations. Elements not directly related to this disclosure are omitted from the illustrations.

[0018] (First Embodiment) Figure 1 is a schematic diagram of a floating seismic isolation system 100 according to the first embodiment. As shown in Figure 1, the floating seismic isolation system 100 includes a liquid storage unit 110, a floating structure 120, a supply device 500, and a control device 600. In Figure 1, the Z direction indicates the vertical direction, the X direction indicates a predetermined first direction among the horizontal directions, and the Y direction indicates a second direction perpendicular to the X direction, which is the first direction among the horizontal directions.

[0019] The liquid storage section 110 includes a recessed section 112 that is recessed vertically downward in the Z direction. Water 114 is stored in the recessed section 112. The water 114 may be natural water such as rainwater, groundwater, spring water, seawater, lake water, or spring water, or it may be artificially treated water such as tap water, industrial water, commercial water, or agricultural water. However, it is not limited to these, and the water 114 may be, for example, an aqueous solution in which a substance is dissolved in water, or any other liquid other than water.

[0020] The floating structure 120 is positioned floating in the water 114, which is the liquid stored in the liquid storage section 110. The floating structure 120 is positioned at a distance in the X, Y, and Z directions from the recessed section 112, which is the wall of the liquid storage section 110.

[0021] The floating structure 120 is, for example, a floating nuclear power plant. However, it is not limited to this, and the floating structure 120 may be a structure of other plants such as a wind power plant, a wave power plant, or a solar power plant, or it may be a structure on which any other equipment is mounted. In this embodiment, the floating structure 120 is, for example, a floating plant that floats on an artificial lake, but it may also be an offshore plant that floats on the sea.

[0022] The floating structure 120 includes a floating body 130 and a plurality of gas containment chambers 140. The floating body 130 is a block body configured to float on water 114. The material of the floating body 130 includes, for example, metal members such as steel plates, plastic resin materials such as fiber-reinforced plastics, and reinforced concrete. The density of the material of the floating body 130 is less than the density of a liquid such as water. The floating body 130 may have a rectangular parallelepiped shape as shown in the figure, but it may also be disc-shaped, cylindrical, elliptical, polygonal, or the like. The floating body 130 has an upper surface 130a, a side surface 130b, and a lower surface 130c.

[0023] The upper surface 130a is the vertically upward rectangular surface of the floating body 130. The side surface 130b is the horizontally rectangular surface of the floating body 130. A pair of side surfaces 130b are formed in the X direction, and a pair of side surfaces 130b are formed in the Y direction. The lower surface 130c is the vertically downward rectangular surface of the floating body 130. The portion of the floating body 130 floating on the water 114 that is on the lower surface 130c side is in contact with the water 114. In other words, the lower side of the floating body 130 is the part that is in contact with the water 114.

[0024] Multiple gas containment chambers 140 are provided in the portion of the floating body 130 that is in contact with the water 114, and are partitioned by an outer wall 132 and multiple inner walls 134. The gas containment chambers 140 are spaces for containing air that can be elastically deformed by vibrations from the water 114. In the first embodiment, an example is described in which the gas contained in the gas containment chambers 140 is air as a mixed gas of multiple pure gases. However, the invention is not limited to this, and the gas contained in the gas containment chambers 140 may be, for example, pure gases such as nitrogen, oxygen, or hydrogen, or any other gas other than air.

[0025] Since the gas containment chamber 140 is provided at the part of the floating body 130 that comes into contact with the water 114, it is formed in a sealed space between the floating body 130 and the water 114. In the first embodiment, the gas containment chamber 140 is formed by recession in the lower surface 130c of the floating body 130. A sealed space is formed inside the gas containment chamber 140. In this embodiment, the sealed space is surrounded by the five walls of the gas containment chamber 140 and the liquid surface of the water 114.

[0026] In the example shown in Figure 1, for example, five gas containment chambers 140 are formed in a row in the X direction on the lower surface 130c side of the floating structure 120, and five sets of five gas containment chambers 140 are formed in a row in the Y direction (see Figure 3). In other words, the floating structure 120 of the first embodiment has a total of 25 gas containment chambers 140. However, it is not limited to this, and the number of gas containment chambers 140 can be two or more. Also, there may be any number of three or more to increase the degree of freedom in adjusting the horizontality.

[0027] The supply device 500 supplies gas to each of the gas containment chambers 140. The supply device 500 is configured to supply gas to each gas containment chamber 140 individually. This allows for individual adjustment of the amount of gas contained in each gas containment chamber 140. In the first embodiment, the supply device 500 supplies air to each of the gas containment chambers 140. However, it is not limited to this, and the supply device 500 may supply each of the gas containment chambers 140 with pure gases such as nitrogen, oxygen, or hydrogen, or any other gas other than air.

[0028] The control device 600 controls the supply device 500. Specifically, the control device 600 controls the supply amount of the gas supplied to each of the gas storage chambers 140. Thereby, the amount of gas stored in each gas storage chamber 140 can be individually controlled. Further, the control device 600 includes, for example, an inclination sensor that detects the inclination of the floating body 130. The control device 600 derives the inclination direction in which the floating body 130 sinks in the -Z direction based on the detection result of the inclination sensor, and supplies gas to the gas storage chamber 140 provided in the derived inclination direction. Thereby, the amount of gas in each gas storage chamber 140 can be controlled so as to maintain the levelness of the floating body 130.

[0029] FIG. 2 is a schematic configuration diagram of the gas storage chamber 140 according to the first embodiment. FIG. 3 is a cross-sectional view taken along the line III-III shown in FIG. 2. As shown in FIGS. 2 and 3, the gas storage chamber 140 includes a plurality of types of gas storage chambers having different volumes from each other.

[0030] Specifically, the gas storage chamber 140 includes a first gas storage chamber 142, a second gas storage chamber 144, and a third gas storage chamber 146. The first gas storage chamber 142 has a first volume, the second gas storage chamber 144 has a second volume smaller than the first volume, and the third gas storage chamber 146 has a third volume smaller than the second volume.

[0031] In the first embodiment, the first gas storage chamber 142, the second gas storage chamber 144, and the third gas storage chamber 146 are rectangular parallelepiped in shape, and the heights in the Z direction are equal to each other. However, the cross-sectional areas of the first gas storage chamber 142, the second gas storage chamber 144, and the third gas storage chamber 146 in the XY plane are different from each other. Specifically, the cross-sectional area of the first gas storage chamber 142 in the XY plane has a first cross-sectional area, the cross-sectional area of the second gas storage chamber 144 in the XY plane has a second cross-sectional area smaller than the first cross-sectional area. Further, the cross-sectional area of the third gas storage chamber 146 in the XY plane has a third cross-sectional area smaller than the second cross-sectional area. Therefore, the volume of the first gas storage chamber 142 becomes larger than the volume of the second gas storage chamber 144, and the volume of the third gas storage chamber 146 becomes smaller than the volume of the second gas storage chamber 144.

[0032] As shown in FIG. 3, the first gas storage chamber 142 is disposed at the center of the floating body 130. The second gas storage chamber 144 and the third gas storage chamber 146 are disposed at the peripheral portion of the floating body 130. Specifically, with respect to the first gas storage chamber 142, in the X direction and the Y direction, a plurality of second gas storage chambers 144 each having a second volume smaller than the first volume are provided. Also, with respect to the first gas storage chamber 142, in the diagonal direction of the floating body 130, a plurality of third gas storage chambers 146 each having a third volume smaller than the first volume are provided.

[0033] FIG. 4 is a partially enlarged view of the second gas storage chamber 144 according to the first embodiment. Here, the configurations of the first gas storage chamber 142 and the third gas storage chamber 146 are the same as those of the second gas storage chamber 144. Therefore, here, the configuration of the second gas storage chamber 144 will be described in detail, and the descriptions of the configurations of the first gas storage chamber 142 and the third gas storage chamber 146 will be omitted. The second gas storage chamber 144 is formed, for example, by a rectangular recess that recesses vertically upward from the lower surface 130c of the floating body 130. However, it is not limited thereto, and the second gas storage chamber 144 may be formed, for example, by a polygonal prism-shaped recess or a cylindrical recess.

[0034] As shown in FIG. 4, the second gas storage chamber 144 has an upper wall 144a, side walls 144b, and an opening 144c. The upper wall 144a is a rectangular wall formed vertically upward in the second gas storage chamber 144. The side walls 144b are rectangular walls formed horizontally in the second gas storage chamber 144. A pair of side walls 144b are formed in the X direction, and a pair of side walls 144b are formed in the Y direction. The opening 144c is formed in a rectangular shape and is formed vertically downward in the second gas storage chamber 144. The second gas storage chamber 144 opens to the lower surface 130c of the floating body 130.

[0035] An orifice 150 is placed in the space within the second gas containment chamber 144. The orifice 150 is an example of a damping member. Here, the damping member is a flat plate-shaped member placed in the space within the second gas containment chamber 144, and is a member that dampens the vibrations of the floating structure 120 caused by seismic waves. The orifice 150 is provided on the side wall 144b of the second gas containment chamber 144. For example, the orifice 150 is provided in the center of the side wall 144b in the Z direction. The orifice 150 is arranged parallel to the XY plane.

[0036] Figure 5 is a view of the orifice 150 shown in Figure 4, in the direction of the arrow in the V direction. As shown in Figure 5, the orifice 150 is formed in the shape of a rectangular flat plate, for example, and a circular cross-section communication hole 152 extending in the Z direction is formed in the center of the XY plane. As shown in Figure 4, the orifice 150 has an upper surface 150a and a lower surface 150b. The communication hole 152 is a through hole that penetrates the orifice 150 from the upper surface 150a to the lower surface 150b.

[0037] In the first embodiment, the number of communication holes 152 formed in the orifice 150 is, for example, one. However, it is not limited to this, and the number of communication holes 152 formed in the orifice 150 may be multiple. That is, at least one communication hole 152 is formed in the orifice 150. The orifice 150 functions as a throttling structure that reduces the horizontal cross-sectional area in the second gas containment chamber 144.

[0038] Returning to Figure 4, the orifice 150 vertically divides the space within the second gas containment chamber 144. The space within the second gas containment chamber 144 is divided by the orifice 150 into a first space 160 vertically below and a second space 170 vertically above. In other words, the orifice 150 is provided between the first space 160 and the second space 170. The communication hole 152 connects the first space 160 and the second space 170. The orifice 150 is an element for dampening air vibrations transmitted from the first space 160 to the second space 170.

[0039] The first space 160 is provided on the lower surface 130c side of the floating body 130 that is in contact with the water 114. The first space 160 is formed by a recess that is recessed inward from the lower surface 130c of the floating body 130. The first space 160 is connected to an opening 144c formed in the lower surface 130c of the floating body 130. Therefore, the first space 160 is in communication with the opening 144c in the lower surface 130c of the floating body 130.

[0040] The second space 170 is located inside the floating body 130 and communicates with the first space 160 via a communication hole 152. One second space 170 communicates with one first space 160. The two communicating first spaces 160 and the two communicating second spaces 170 form a pair. As described above, multiple gas containment chambers 140 are formed inside the floating body 130. Therefore, multiple pairs of first spaces 160 and second spaces 170 are provided inside the floating body 130.

[0041] Thus, in the first embodiment, the orifice 150 is placed in the space within the gas containment chamber 140. As a result, a resistance force is generated when air passes through the communication hole 152 of the orifice 150, and this resistance force acts as a damping force in the vibration response caused by the wave transmission of seismic waves to the floating structure 120. This damping force can suppress the vibration response of the floating structure 120 caused by the wave transmission of seismic waves.

[0042] Figure 6 is a schematic diagram showing an example of the size of the communication holes 152 of the orifices 150 provided in each gas containment chamber 140. As shown in Figure 6, the diameter of the communication holes 152 of the orifices 150 differs in the first gas containment chamber 142, the second gas containment chamber 144, and the third gas containment chamber 146. The diameter of the communication holes 152 of the orifices 150 differs according to the volume or cross-sectional area of ​​the gas containment chamber 140. In the first embodiment, the diameter of the communication holes 152 becomes smaller for gas containment chambers 140 with smaller volumes. Specifically, the diameter of the communication hole 152 in the third gas containment chamber 146 is smaller than the diameter of the communication hole 152 in the second gas containment chamber 144. Also, the diameter of the communication hole 152 in the second gas containment chamber 144 is smaller than the diameter of the communication hole 152 in the first gas containment chamber 142. Furthermore, instead of the diameter of the communication hole 152 of the orifice 150, the cross-sectional area of ​​the communication hole 152 may be different. For example, the cross-sectional area of ​​the communication hole 152 of the third gas containment chamber 146 may be smaller than the cross-sectional area of ​​the communication hole 152 of the second gas containment chamber 144. Also, the cross-sectional area of ​​the communication hole 152 of the second gas containment chamber 144 may be smaller than the cross-sectional area of ​​the communication hole 152 of the first gas containment chamber 142.

[0043] In the first embodiment, when the floating structure 120, water 114, and the gas in the gas containment chamber 140 are considered as a single system, the diameter of the communication hole 152 of the orifice 150 is such that the seismic input to the floating structure 120 is X ０ The movement of air at the position of orifice 150 is X １ The displacement of the floating body 130 in the Z direction is X ２ The value is set based on the system. Below, the earthquake input to the floating structure 120 is X ０ The movement of air at the position of orifice 150 is X １ The displacement of the floating body 130 in the Z direction is X ２ A system that behaves in this way is sometimes called a system that responds to seismic waves.

[0044] Here, the mass of the floating body 130 is m, and the spring constant of the first space 160 is k. １ The spring constant of the second space 170 is k. ２In addition, when the spring constant of the first space 160 is equal to the spring constant of the second space 170, let the spring constants of the first space 160 and the second space 170 be k0 (= k1 = k2) respectively, and let the equivalent viscous damping coefficient of the second space 170 that functions as a damper simulating the pressure loss of the orifice 150 be ceq, and establish the equation of motion. Earthquake input X ０ The relative displacement of the floating body 130 as seen from ｒ is X. When the frequency is ω, the frequency response function (X ｒ / X ０ ) of the system responding to the seismic wave is obtained by the following formula (1). That is, according to formula (1), the frequency response function (X ｒ / X ０ ) of the floating body 130, the water 114, the gas in the gas storage chamber 140, and the orifice 150 acting as a single system in response to the seismic wave is obtained

[0045] X ｒ : Earthquake input X ０ The relative displacement [m] of the floating body 130 as seen from X ０ : Earthquake input [m] ceq: The equivalent viscous damping coefficient [N / (m / s)] of the second space 170 that functions as a damper simulating the pressure loss of the orifice 150 m: The mass [kg] of the floating body 130 ω: Frequency [Hz] k １ : The spring constant [N / m] of the first space 160 k ２ : The spring constant [N / m] of the second space 170 k ０ : The spring constant [N / m] of each of the first space 160 and the second space 170.

[0046] When the ceq is determined by substituting each preamble value into formula (1) so that the maximum response of the frequency response becomes small, the coefficient C2 of the velocity-squared proportional damping of the second space 170 that functions as a damper simulating the pressure loss of the orifice 150 can be obtained by the following formula (2).

[0047] c ２: Coefficient of velocity-squared proportional damping of the second space 170, which functions as a damper simulating the pressure loss of the orifice 150 [[N / (m / s)^2]] ceq: Equivalent viscous damping coefficient [N / (m / s)] of the second space 170, which functions as a damper simulating the pressure loss of the orifice 150.

[0048] Using the coefficient C2 obtained by equation (2), the horizontal cross-sectional area A0 of the communication hole 152 of the orifice 150 can be calculated by the following equation (3). Here, let A be the horizontal cross-sectional area of ​​the gas containment chamber 140, C be the flow coefficient, and ρ be the density of the gas in the gas containment chamber 140.

[0049] A ０ : Horizontal cross-sectional area A0 [mm²] of the communication hole 152 of the orifice 150 ２ ] A: Horizontal cross-sectional area of ​​gas containment chamber 140 [mm² ２ ] C: Flow coefficient [-] ρ: Density of gas in gas containment chamber 140 [g / cm³] 3 ].

[0050] In the first embodiment, since the communication hole 152 is circular in shape, the diameter d0 of the communication hole 152 of the orifice 150 can be determined by the following formula (4) using the cross-sectional area A0 of the orifice 150 obtained by formula (3). Thus, the diameter d0 of the communication hole 152 of the orifice 150 is the frequency response function (X) of the system that responds to seismic waves. ｒ / X ０ The value will be set based on the following criteria.

[0051] Figure 7 is a graph showing the relationship between the horizontal cross-sectional area A0 of the communication hole 152 of the orifice 150 and the horizontal cross-sectional area A of the gas containment chamber 140. The damping capacity of the orifice 150 is best exhibited in this ratio relationship. As shown in Figure 7, the relationship between the horizontal cross-sectional area A0 of the communication hole 152 of the orifice 150 and the horizontal cross-sectional area A of the gas containment chamber 140 can be represented by a quadratic curve. The horizontal cross-sectional area A0 of the communication hole 152 becomes smaller than the size proportional to the horizontal cross-sectional area A of the gas containment chamber 140 as the horizontal cross-sectional area A of the gas containment chamber 140 decreases. Specifically, for example, the value obtained by dividing the horizontal cross-sectional area A0 of the communication hole 152 of the orifice 150 provided in the first gas containment chamber 142 by the horizontal cross-sectional area A of the first gas containment chamber 142 is greater than the value obtained by dividing the horizontal cross-sectional area A0 of the communication hole 152 of the orifice 150 provided in the second gas containment chamber 144 by the horizontal cross-sectional area A of the second gas containment chamber 144. As mentioned above, Figure 7 shows the relationship that maximizes the damping capacity of the orifice 150, and it is possible to achieve damping capacity even if the relationship deviates from this.

[0052] Incidentally, depending on the layout and center of gravity of the floating structure 120, the horizontal balance of the floating structure 120 may be disrupted, and its horizontal alignment may not be maintained.

[0053] Therefore, the floating structure 120 according to the first embodiment includes a plurality of gas storage chambers 140, each of which includes at least one first gas storage chamber 142 having a first volume and a second gas storage chamber 144 having a second volume smaller than the first volume. Since the second gas storage chamber 144 has a smaller volume than the first gas storage chamber 142, the amount of gas can be adjusted more precisely than in the first gas storage chamber 142. As a result, compared to the case where all of the plurality of gas storage chambers 140 are composed of first gas storage chambers 142, it becomes possible to finely adjust the horizontal balance of the floating structure 120, making it easier to maintain the horizontality of the floating structure 120. Furthermore, the plurality of gas storage chambers 140 includes at least one first gas storage chamber 142 having a first volume and at least two or more second gas storage chambers 144 having a second volume smaller than the first volume. This allows for more precise adjustment of the amount of gas in each gas-containing chamber 140 in the X direction compared to, for example, a case where multiple gas-containing chambers 140 arranged in the X direction are all composed of the same volume. As a result, it becomes possible to finely adjust the horizontal balance of the floating structure 120 and maintain the horizontality of the floating structure 120.

[0054] Furthermore, the floating structure 120 according to the first embodiment includes a supply device 500 that supplies gas to each of the gas containment chambers 140, and a control device 600 that controls the amount of gas supplied to each of the gas containment chambers 140. This allows for the individual supply of gas to each gas containment chamber 140 and the individual control of the amount of gas supplied to each gas containment chamber 140. The control device 600 also derives the tilt direction in which the floating body 130 sinks in the -Z direction based on the detection result of the tilt sensor, and supplies gas to the gas containment chamber 140 provided in the derived tilt direction. For example, if the +X side of the floating body 130 tilts in the -Z direction, the control device 600 causes the supply device 500 to supply gas in order to increase the amount of gas in the second gas containment chamber 144 provided on the +X side of the floating body 130. This makes it possible to finely adjust the horizontal balance of the floating structure 120 and maintain the horizontality of the floating structure 120.

[0055] Furthermore, in the first embodiment, the first gas containment chamber 142 is located in the center of the floating body 130, and the second gas containment chamber 144 is located in the periphery of the floating body 130. This allows for precise control of the amount of gas in the gas containment chamber 140, which has a smaller volume, near the outer wall 132 located away from the center of the floating body 130, enabling accurate adjustment of the tilt of the floating body 130 in the roll direction around the Y axis and the pitch direction around the X axis. The diameter of the orifice 150 in the second gas containment chamber 144 is smaller than the diameter of the orifice 150 in the first gas containment chamber 142. This enhances the damping effect of the orifice 150 in the gas containment chamber 140 near the outer wall 132 located away from the center of the floating body 130. As a result, the horizontality of the floating structure 120 can be maintained.

[0056] Furthermore, the diameter of the orifice 150 in the first embodiment is set based on the frequency response function that responds to seismic waves when the floating body 130, water 114, gas in the gas containment chamber 140, and orifice 150 act as a single system. This allows the orifice 150 to exert an appropriate damping effect when seismic waves are input, for each gas containment chamber 140 with different volumes. Also, the value obtained by dividing the horizontal cross-sectional area A0 of the communication hole 152 of the orifice 150 provided in the first gas containment chamber 142 by the horizontal cross-sectional area A of the first gas containment chamber 142 is greater than the value obtained by dividing the horizontal cross-sectional area A0 of the communication hole 152 of the orifice 150 provided in the second gas containment chamber 144 by the horizontal cross-sectional area A of the second gas containment chamber 144. This allows the orifice 150 to exert its maximum damping capacity. Furthermore, the plurality of gas containment chambers 140 in the first embodiment comprises at least nine or more gas containment chambers. Furthermore, at least nine gas containment chambers are arranged in a row of three or more in a first horizontal direction, and in a row of three or more in a second horizontal direction that intersects with the first horizontal direction. This allows for fine adjustment of the amount of gas in each gas containment chamber 140 in the X and Y directions. As a result, it becomes possible to finely adjust the horizontal balance of the floating structure 120 and maintain the horizontality of the floating structure 120.

[0057] (Second Embodiment) Figure 8 is a schematic diagram of the gas containment chamber 240 according to the second embodiment. Figure 9 is a cross-sectional view taken along the line IX-IX shown in Figure 8. Components that are substantially the same as those of the floating structure 120 in the first embodiment are denoted by the same reference numerals and their descriptions are omitted. As shown in Figures 8 and 9, the gas containment chamber 240 includes multiple types of gas containment chambers with different volumes.

[0058] Specifically, the gas containment chamber 240 includes a first gas containment chamber 242, a second gas containment chamber 244, a third gas containment chamber 246, a fourth gas containment chamber 248, a fifth gas containment chamber 250, and a sixth gas containment chamber 252. The first gas containment chamber 242 has a first volume, the second gas containment chamber 244 has a second volume smaller than the first volume, and the third gas containment chamber 246 has a third volume smaller than the second volume. Furthermore, the fourth gas containment chamber 248 has a fourth volume smaller than the third volume, the fifth gas containment chamber 250 has a fifth volume smaller than the fourth volume, and the sixth gas containment chamber 252 has a sixth volume smaller than the fifth volume.

[0059] Furthermore, unlike the first embodiment described above, in the X direction, three types of first gas storage chambers 242, second gas storage chamber 244, and third gas storage chamber 246 with different volumes are arranged side by side. In the Y direction, three types of first gas storage chambers 242, second gas storage chamber 244, and third gas storage chamber 246 with different volumes are also arranged side by side. Moreover, in the diagonal direction of the floating body 130, four types of first gas storage chambers 242, fourth gas storage chamber 248, fifth gas storage chamber 250, and sixth gas storage chamber 252 with different volumes are also arranged side by side. In the second embodiment, the first gas containment chamber 242, the second gas containment chamber 244, and the third gas containment chamber 246 are arranged in the order of first gas containment chamber 242, second gas containment chamber 244, and third gas containment chamber 246, from the center of the floating body 130 toward the outer wall 132 in the X and Y directions. In addition, the first gas containment chamber 242, the fourth gas containment chamber 248, the fifth gas containment chamber 250, and the sixth gas containment chamber 252 are arranged in the order of first gas containment chamber 242, fourth gas containment chamber 248, fifth gas containment chamber 250, and sixth gas containment chamber 252, from the center of the floating body 130 toward the outer wall 132 in the diagonal direction.

[0060] The first gas chamber 242, the second gas chamber 244, the third gas chamber 246, the fourth gas chamber 248, the fifth gas chamber 250, and the sixth gas chamber 252 are rectangular parallelepipeds, and their heights in the Z direction are equal. However, the cross-sectional areas in the XY plane of the first gas chamber 242, the second gas chamber 244, the third gas chamber 246, the fourth gas chamber 248, the fifth gas chamber 250, and the sixth gas chamber 252 are different from each other. Specifically, the cross-sectional area of ​​the XY plane of the first gas chamber 242 is a first cross-sectional area, the cross-sectional area of ​​the XY plane of the second gas chamber 244 is a second cross-sectional area which is smaller than the first cross-sectional area, and the cross-sectional area of ​​the XY plane of the third gas chamber 246 is a third cross-sectional area which is smaller than the second cross-sectional area. Furthermore, the cross-sectional area of ​​the fourth gas containment chamber 248 in the XY plane is smaller than the cross-sectional area of ​​the third gas containment chamber. Similarly, the cross-sectional area of ​​the fifth gas containment chamber 250 in the XY plane is smaller than the cross-sectional area of ​​the fourth gas containment chamber. Also, the cross-sectional area of ​​the sixth gas containment chamber 252 in the XY plane is smaller than the cross-sectional area of ​​the fifth gas containment chamber. Therefore, the volumes decrease in the order of the first gas containment chamber 242, the second gas containment chamber 244, the third gas containment chamber 246, the fourth gas containment chamber 248, the fifth gas containment chamber 250, and the sixth gas containment chamber 252.

[0061] As shown in Figure 9, the first gas containment chamber 242 is located in the central part of the floating body 130. The second gas containment chamber 244, the third gas containment chamber 246, the fourth gas containment chamber 248, the fifth gas containment chamber 250, and the sixth gas containment chamber 252 are located in the peripheral part of the floating body 130. Specifically, relative to the first gas containment chamber 242, the second gas containment chamber 244, having a second volume smaller than the first volume, and the third gas containment chamber 246, having a third volume smaller than the second volume, are provided in the X and Y directions. In addition, relative to the first gas containment chamber 242, the fourth gas containment chamber 248, having a fourth volume smaller than the first volume, the fifth gas containment chamber 250, having a fifth volume smaller than the fourth volume, and the sixth gas containment chamber 252, having a sixth volume smaller than the fifth volume, are provided in the diagonal direction of the floating body 130.

[0062] In the second embodiment, the first gas containment chamber 242, the second gas containment chamber 244, and the third gas containment chamber 246 are arranged in the order of first gas containment chamber 242, second gas containment chamber 244, and third gas containment chamber 246, from the center of the floating body 130 toward the outer wall 132. As a result, the volume of the gas containment chamber 240 decreases as it approaches the outer wall 132 of the floating body 130, allowing for more precise adjustment of the tilt of the floating body 130 in the roll direction around the Y axis and the pitch direction around the X axis compared to the first embodiment. Furthermore, the diameter of the communication hole 152 of the orifice 150 provided in the gas containment chamber 240 becomes smaller for the gas containment chamber 240 with the smallest volume among the three or more gas containment chambers 240. As a result, the damping effect of the orifice 150 in the gas containment chamber 240 can be increased as it approaches the outer wall 132 of the floating body 130. As a result, it becomes easier to maintain the horizontality of the floating structure 120 compared to the first embodiment.

[0063] (Third Embodiment) Figure 10 is a schematic diagram of the gas containment chamber 340 according to the third embodiment. Figure 11 is a cross-sectional view taken along the line XI-XI shown in Figure 10. Components that are substantially the same as those of the floating structure 120 of the first embodiment are denoted by the same reference numerals and their descriptions are omitted. As shown in Figures 10 and 11, the gas containment chamber 340 includes a plurality of gas containment chambers of different volumes.

[0064] Specifically, the gas containment chamber 340 includes a first gas containment chamber 342, a second gas containment chamber 344, and a third gas containment chamber 346. The first gas containment chamber 342 has a first volume, the second gas containment chamber 344 has a second volume smaller than the first volume, and the third gas containment chamber 346 has a third volume smaller than the second volume.

[0065] In the third embodiment, the first gas chamber 342, the second gas chamber 344, and the third gas chamber 346 are rectangular parallelepipeds, and their heights in the Z direction are equal. However, the cross-sectional areas of the first gas chamber 342, the second gas chamber 344, and the third gas chamber 346 in the XY plane are different from each other. Specifically, the cross-sectional area of ​​the first gas chamber 342 in the XY plane is a first cross-sectional area, and the cross-sectional area of ​​the second gas chamber 344 in the XY plane is a second cross-sectional area which is smaller than the first cross-sectional area. Also, the cross-sectional area of ​​the third gas chamber 346 in the XY plane is a third cross-sectional area which is smaller than the second cross-sectional area. Therefore, the volume of the first gas chamber 342 is larger than the volume of the second gas chamber 344, and the volume of the third gas chamber 346 is smaller than the volume of the second gas chamber 344.

[0066] As shown in Figure 11, the first gas containment chamber 342 and the second gas containment chamber 344 are located in the periphery of the floating body 130. The third gas containment chamber 346 is located in the central part of the floating body 130. Specifically, relative to the third gas containment chamber 346, the second gas containment chamber 344 is provided in the X and Y directions, having a second volume larger than the third volume. In addition, relative to the third gas containment chamber 346, the first gas containment chamber 342 is provided in the diagonal direction of the floating body 130, having a first volume larger than the third volume.

[0067] According to the third embodiment, the third gas containment chamber 346, which has the smallest volume, is located in the center of the floating body 130. This allows for precise adjustment of the tilt of the floating body 130 in the roll direction around the Y axis and the pitch direction around the X axis by precisely controlling the amount of gas in the third gas containment chamber 346 in the center of the floating body 130 when a slight tilt occurs in the floating body 130.

[0068] While embodiments of this disclosure have been described above with reference to the attached drawings, it goes without saying that this disclosure is not limited to such embodiments. It will be obvious to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of this disclosure.

[0069] 100 Floating seismic isolation system 110 Liquid storage section 114 Water (liquid) 120 Floating structure 130 Floating body 132 Outer wall 134 Inner wall 140 Gas containment chamber 142 First gas containment chamber 144 Second gas containment chamber 146 Third gas containment chamber 150 Orifice 152 Communication hole 160 First space 170 Second space 500 Supply device 600 Control device

Claims

1. A floating structure comprising: a floating body capable of floating in a liquid; a plurality of gas-containing chambers provided on the lower side of the floating body and partitioned by an inner wall and an outer wall; and an orifice provided in each of the gas-containing chambers, wherein the plurality of gas-containing chambers include at least one first gas-containing chamber having a first volume and a second gas-containing chamber having a second volume smaller than the first volume.

2. The floating structure according to claim 1, wherein the plurality of gas containment chambers include at least three or more gas containment chambers, and the three or more gas containment chambers include at least one first gas containment chamber having the first volume and at least two or more second gas containment chambers having the second volume.

3. The floating structure according to claim 1, wherein the first gas containment chamber is located in the center of the floating body, the second gas containment chamber is located in the peripheral part of the floating body, and the diameter of the orifice of the second gas containment chamber is smaller than the diameter of the orifice of the first gas containment chamber.

4. The floating structure according to claim 1, wherein the diameter of the orifice is set based on a frequency response function that responds to seismic waves when the floating body, the liquid, the gas in the gas containment chamber, and the orifice act as a single system.

5. The floating structure according to claim 1, wherein the value obtained by dividing the horizontal cross-sectional area of ​​the communication hole of the orifice provided in the first gas containment chamber by the horizontal cross-sectional area of ​​the first gas containment chamber is greater than the value obtained by dividing the horizontal cross-sectional area of ​​the communication hole of the orifice provided in the second gas containment chamber by the horizontal cross-sectional area of ​​the second gas containment chamber.

6. The floating structure according to claim 2, wherein the diameter of the orifice provided in the gas-containing chamber is smaller for each of the three or more gas-containing chambers with a smaller volume.

7. The floating structure according to claim 1, wherein the plurality of gas containment chambers include at least nine gas containment chambers, and the nine or more gas containment chambers are arranged in a row of three or more in a first horizontal direction, and in a row of three or more in a second horizontal direction intersecting the first horizontal direction.

8. A floating structure according to any one of claims 1 to 7, comprising: a supply device for supplying gas to each of the gas containment chambers; and a control device for controlling the amount of gas supplied to each of the gas containment chambers.

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