Device and method for inhibiting bulge for ground-level rectangular water reservoir

Abstract

To provide a device for inhibiting bulge for a ground-level rectangular water reservoir allowed to inhibit a ground-level rectangular water reservoir from bulging.SOLUTION: A device 3 for inhibiting bulge comprises an outside vibration-damping member 7 that is set up on an outer surface of a side plate 4 having a plurality of panels 5 arranged in vertical and horizontal directions and extends in the horizontal direction over the plurality of panels 5. By the external vibration-damping member 7, the side plate 4 is split vertically.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bulging suppression device and method for an above-ground rectangular water tank used as a water distribution reservoir, a water storage tank, etc. [Background technology]

[0002] A distribution reservoir is a purified water storage tank that receives water from a water purification plant and distributes it according to the demand in the distribution area. Although not as large as a distribution reservoir, water tanks with the same function as a distribution reservoir are also installed in large buildings such as hospitals, schools, and apartment buildings.

[0003] From the viewpoint of efficient use of land and ease of maintenance, above-ground rectangular tanks are widely used as distribution reservoirs, storage tanks, etc. Panel tanks, which are made up of many joined panels, are often used as above-ground rectangular tanks.

[0004] However, because the side plates of panel tanks are thin and have low rigidity, there have been many reports of earthquake damage in recent years due to the generation of additional hydrodynamic pressure (deformation pressure) caused by bulging. As shown in Figure 10, hydrodynamic pressure during an earthquake consists of hydrodynamic pressure (rigid body pressure) resulting from the inertial force of the water content 22 due to the earthquake and hydrodynamic pressure (deformation pressure) resulting from the deformation of the tank's side plates 21. Bulging is a phenomenon in which the tank's side plates 21 and the water content 22 vibrate in a coupled manner, generating hydrodynamic pressure (rigid body pressure) due to the movement of the water content 22 as well as hydrodynamic pressure (deformation pressure) due to the bulging deformation of the side plates 21. When the natural period of the side plates 21 matches the periodic characteristics of an earthquake, the side plates 21 and the water content 22 vibrate in a coupled manner, increasing the deformation pressure and generating hydrodynamic pressure during an earthquake that is greater than expected.

[0005] In order to suppress bulging, Patent Document 1 proposes providing a vibration damping device 32 on the underside of the water tank 31 as shown in Figure 11. By providing the vibration damping device 32, the natural period of the water tank 31 and the periodic characteristics of an earthquake are prevented from matching. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-199264 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when installing the vibration damping device described in Patent Document 1 in an existing above-ground rectangular water tank, the tank must be lifted up, which is particularly difficult when installing a large tank that is currently in operation.

[0008] The present invention has been made in consideration of the above-mentioned problems, and has as its object to provide a bulging suppression device and method for an above-ground rectangular water tank that can suppress bulging in an above-ground rectangular water tank. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, one aspect of the present invention is a bulging suppression device for an above-ground rectangular water tank, which comprises an external seismic damping member installed on the outer surface of a side panel having a plurality of panels arranged vertically and horizontally and extending horizontally across the plurality of panels, and which divides the side panel into upper and lower parts by the external seismic damping member.

[0010] Another aspect of the present invention is a bulging suppression method for an above-ground rectangular water tank, in which an external seismic damping member extending horizontally across a plurality of panels is installed on the outer surface of a side panel having a plurality of panels arranged vertically and horizontally, and the external seismic damping member divides the side panel into upper and lower sections. [Effects of the Invention]

[0011] According to the present invention, the range of vibration modes of the side panels is divided by the external vibration-damping members installed on the side panels, which significantly improves the vibration characteristics of the side panels and the entire water tank from the perspective of earthquake countermeasures. Specifically, the external vibration-damping members increase the natural frequency of the side panels and the entire water tank and reduce the natural period, which prevents the natural period of the water tank (side panels) from coinciding with the periodic characteristics of an earthquake, thereby suppressing bulging. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view of an above-ground rectangular water tank to which a bulging suppression device according to a first embodiment of the present invention is applied. [Figure 2] FIG. 2 is an enlarged view of part II in FIG. [Figure 3] FIG. 1 is a perspective view of the panel as seen from inside the tank. [Figure 4] FIG. 10 is a perspective view of an above-ground rectangular water tank to which a modified example of the bulging suppression device of the present embodiment is applied. [Figure 5] FIG. 5(a) is a diagram showing the vibration mode of the side panel when no external vibration-damping member is provided, and FIG. 5(b) is a diagram showing the vibration mode of the side panel when an external vibration-damping member is provided. [Figure 6] FIG. 10 is a perspective view of an above-ground rectangular water tank to which a bulging suppression device according to a second embodiment of the present invention is applied. [Figure 7] FIG. 7 is an enlarged view of part VII in FIG. [Figure 8] FIG. 10 is a perspective view of an above-ground rectangular water tank to which a bulging suppression device according to a third embodiment of the present invention is applied. [Figure 9] FIG. 10 is a perspective view of an above-ground rectangular water tank to which a bulging suppression device according to a fourth embodiment of the present invention is applied. [Figure 10] This is a schematic diagram showing the relationship between hydrodynamic pressure, rigid body pressure, and deformation pressure during an earthquake. [Figure 11] FIG. 1 is a perspective view of a conventional above-ground rectangular water tank. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a bulging suppression device and method for an above-ground rectangular water tank according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the bulging suppression device and method of the present invention may be embodied in various forms and are not limited to the embodiments described in the specification. The present embodiment is provided with the intention of enabling those skilled in the art to fully understand the invention by fully disclosing the specification. (First embodiment)

[0014] FIG. 1 shows a perspective view of an above-ground rectangular water tank 1 to which a bulging suppression device 3 according to a first embodiment of the present invention is applied. The above-ground rectangular water tank 1 comprises a bottom plate 2, four side plates 4 attached to the periphery of the bottom plate 2, and a roof plate 6, and is formed in a rectangular shape in plan view. For ease of maintenance, the water tank 1 may be configured as a two-tank structure, with a partition plate provided to separate the water tank 1. The side plates 4 and the partition plate are reinforced by internal reinforcing members (not shown) to resist the water pressure acting on the side plates 4 and the partition plate. The internal reinforcing members are called braces and include horizontal and diagonal members.

[0015] The side panels 4 are provided with a plurality of panels 5 arranged vertically and horizontally. The panels 5 are made of steel, FRP, etc. The same is true for the bottom panel 2 and the roof panel 6. The plurality of panels 5 are joined together by welding or bolts.

[0016] FIG. 3 shows a perspective view of panel 5 as seen from inside aquarium 1. Panel 5 comprises a rectangular base plate 5a and connecting flanges 5b attached to the four periphery of base plate 5a. Base plate 5a has protrusions 5a1 (which are convex when viewed from the outside of aquarium 1 and concave when viewed from the inside of aquarium 1) that protrude outward from aquarium 1 to increase the rigidity of panel 5. (These protrusions 5a1 are spherical, diamond-cut, or have other shapes.) The connecting flanges 5b are curved from base plate 5a toward the inside of aquarium 1, and do not protrude from the outer surfaces of side panels 4.

[0017] As shown in FIG. 1 , the bulging suppression device 3 includes an external seismic damping member 7 that is installed on the outer surface of a side plate 4 and extends horizontally across multiple panels 5. The external seismic damping member 7 is an axially long steel member formed with a constant cross section, such as a C-shaped, H-shaped, L-shaped, or I-shaped cross section, and is, for example, a steel beam or a strip-shaped flat plate. The external seismic damping member 7 is installed at the joint between the upper and lower panels 5. The external seismic damping member 7 divides the side plate 4 into upper and lower parts. Note that, in this embodiment, the side plate 4 is divided into two parts, upper and lower, but as shown in FIG. 4 , the side plate 4 may be divided into three or more parts by two or more external seismic damping members 7. Furthermore, two or more panels 5 may be located above and / or below the external seismic damping member 7.

[0018] The external vibration damping members 7 are installed on the outer surfaces of the four side plates 4 and extend over substantially the entire horizontal length of each side plate 4. In this embodiment, the four external vibration damping members 7 are not joined to each other and are separate from each other.

[0019] As shown in Figure 2, a mounting frame 8 is attached to the joint between the upper and lower panels 5 by welding, bolting, etc. An external seismic damping member 7 is attached to the mounting frame 8 by bolting, welding, etc. The force with which the external seismic damping member 7 fastens the side panel 4 in the perpendicular direction may be adjustable. For example, an elongated hole may be formed in the mounting frame 8, allowing the external seismic damping member 7 to move through the elongated hole. (Action and effect)

[0020] The risk of bulging increases when the natural period of the side panel 4 matches the periodic characteristics of an earthquake. The natural period of the side panel 4 depends on the rigidity of the side panel 4 and the size of the side panel 4 that vibrates uniformly. "Uniform vibration" means that the multiple panels 5 of the side panel 4 vibrate as a unit. Here, the larger the side panel 4 that vibrates uniformly, the smaller its natural frequency and the larger its natural period.

[0021] Figure 5(a) shows the vibration mode of the side panel 4 without the external vibration-damping member 7, and Figure 5(b) shows the vibration mode of the side panel 4 with the external vibration-damping member 7. As shown in Figure 5(a), without the external vibration-damping member 7, the primary vibration mode of the side panel 4, which vibrates uniformly, has the largest amplitude in the vertical center, as shown in the figure. On the other hand, as shown in Figure 5(b), with the external vibration-damping member 7 installed on the side panel 4, the range of the vibration mode of the side panel 4 is divided into upper and lower parts, and the primary vibration mode of the side panel 4, which vibrates uniformly, has the largest amplitude in the vertical center of the divided range, as shown in the figure. By dividing the range of the vibration mode of the side panel 4 with the external vibration-damping member 7 in this way, the vibration characteristics of the side panel 4 and the entire aquarium 1 can be significantly improved from the perspective of earthquake countermeasures. Specifically, the external vibration control member 7 increases the natural frequency of the side panels 4 and the entire water tank 1 and reduces the natural period, thereby preventing the natural period of the water tank 1 (side panels 4) from matching with the periodic characteristics of an earthquake, thereby suppressing bulging.

[0022] The bulging suppression device 3 of this embodiment further provides the following effects: The force with which the external vibration damping member 7 tightens the side plate 4 in the perpendicular direction can be adjusted, so the vibration characteristics of the side plate 4 can be varied in a variety of ways.

[0023] Since the external vibration-damping member 7 is disposed at the joint between the upper and lower panels 5, the external vibration-damping member 7 can prevent the protrusion 5a1 of the panel 5 from being deformed.

[0024] Since the joining flange 5b of the panel 5 is bent from the base plate 5a toward the inside of the water tank 1, the joining flange 5b of the panel 5 can be prevented from protruding from the outer surface of the side plate 4 and interfering with the external vibration control member 7.

[0025] The bulging suppression device 3 of this embodiment may be applied to a newly constructed above-ground rectangular water tank 1 or to an existing above-ground rectangular water tank 1. When applied to an existing above-ground rectangular water tank 1, the external seismic damping member 7 can be installed without draining the water. (Second embodiment)

[0026] 6 shows a perspective view of an above-ground rectangular water tank 11 to which a bulging suppression device 13 according to a second embodiment of the present invention is applied. Similar to the above-ground rectangular water tank 1, the above-ground rectangular water tank 11 is formed in a rectangular shape in plan view, and includes a bottom plate 12, four side plates 14 attached to the periphery of the bottom plate 12, a partition plate (not shown), and a roof plate 16. The side plates 14 and the partition plate are reinforced by internal reinforcing members (not shown) to resist the water pressure acting on the side plates 14 and the partition plate.

[0027] The side panels 14 are made up of multiple panels 5 arranged vertically and horizontally, as are the bottom panel 12 and roof panel 16. The configuration of the panels 5 is substantially the same as that of the panels 5 of the above-ground rectangular aquarium 1 of the first embodiment, so the same reference numerals are used and a description thereof will be omitted.

[0028] The bulging suppression device 13 of the second embodiment is installed on the outer surface of the side plate 14 and includes two upper and lower external seismic damping members 17a, 17b that extend horizontally across multiple panels 5. The four upper external seismic damping members 17a are installed on the outer surface of the side plate 14 via mounting racks 18. The configurations of the mounting racks 18 and the external seismic damping members 17a are the same as the configurations of the mounting racks 8 and the external seismic damping members 7 of the bulging suppression device 3 of the first embodiment.

[0029] In the bulging suppression device 13 of the second embodiment, the four upper external vibration damping members 17a are directly connected to each other and formed into a frame shape. As shown in FIG. 7, the ends of two adjacent external vibration damping members 17a are joined to each other with bolts 25 or by welding. The four upper external vibration damping members 17a wrap around the above-ground rectangular water tank 11 like a headband. To prevent deformation of the side panels 14, a cushioning material such as rubber may be interposed between the external vibration damping members 17a and the side panels 14. The four lower external vibration damping members 17b are also directly connected to each other and formed into a frame shape.

[0030] The force with which the frame-shaped external vibration damping members 17a, 17b tighten the side panel 14 may be adjustable. For example, by providing elongated holes or the like similar to those in the first embodiment at the joints of the external vibration damping members 17a, 17b, the force with which the side panel 14 is tightened can be adjusted.

[0031] The bulging suppression device 13 of the second embodiment not only provides the same effects as the bulging suppression device 3 of the first embodiment, but also provides the following effects.

[0032] Because the external vibration damping members 17a, 17b are connected to each other and formed into a frame, they effectively resist the force that tends to cause the side panels 14 to expand during an earthquake, and the portions of the side panels 14 where the external vibration damping members 17a, 17b are provided are less likely to expand. Therefore, the external vibration damping members 17a, 17b can reliably divide the range of vibration modes of the side panels 14. Furthermore, the dynamic water pressure acting on one side of the side panel 14 can be transmitted to the opposite side panel 14 via the external vibration damping members 17a, 17b, further increasing the rigidity of the side panels 14. (Third embodiment)

[0033] FIG. 8 shows a perspective view of an above-ground rectangular water tank 20 to which a bulging suppression device 23 according to a third embodiment of the present invention is applied.

[0034] Similar to the above-ground rectangular water tank 11 of the second embodiment, the above-ground rectangular water tank 20 of the third embodiment is rectangular in plan view and includes a bottom plate 12, four side plates 14 attached to the periphery of the bottom plate 12, a partition plate (not shown), and a roof plate 16. The side plates 14 and the partition plate are reinforced by internal reinforcing members (not shown) to resist water pressure acting on the side plates 14 and the partition plate. The configurations of the bottom plate 12, side plates 14, and roof plate 16 are substantially the same as those of the above-ground rectangular water tank 11 of the second embodiment, so the same reference numerals are used and their description will be omitted.

[0035] Similar to the bulging suppression device 13 of the second embodiment, the bulging suppression device 23 of the third embodiment includes two upper and lower frame-shaped external seismic damping members 17a, 17b that are arranged at the joints of the panels 14. In addition to the two upper and lower frame-shaped external seismic damping members 17a, 17b, the bulging suppression device 23 of the third embodiment also includes a frame-shaped external seismic damping member 17c that is arranged in the center of the panel 5 between them. The configuration of the frame-shaped external seismic damping member 17c is the same as that of the frame-shaped external seismic damping members 17a, 17b.

[0036] According to the bulging suppression device 23 of the third embodiment, a frame-shaped external vibration suppression member 17c is additionally installed in the center of the panel 5, so that the vibration suppression effect can be further enhanced compared to the bulging suppression device 13 of the second embodiment. (Fourth embodiment)

[0037] FIG. 9 shows a perspective view of an above-ground rectangular water tank 20 to which a bulging suppression device 33 according to a fourth embodiment of the present invention is applied. Similar to the above-ground rectangular water tank 11 according to the second embodiment, the above-ground rectangular water tank 20 according to the fourth embodiment comprises a bottom plate 12, four side plates 14 attached to the periphery of the bottom plate 12, a partition plate (not shown), and a roof plate 16, and is rectangular in plan view. The side plates 14 and the partition plate are reinforced by internal reinforcing members (not shown) to resist water pressure acting on them. The configurations of the bottom plate 12, side plates 14, and roof plate 16 are substantially identical to those of the above-ground rectangular water tank 11 according to the second embodiment, and therefore the same reference numerals are used and their description will be omitted.

[0038] The bulging suppression device 33 of the fourth embodiment is installed on the outer surface of the side plate 14 and includes two upper and lower external seismic damping members 17a, 17b that extend horizontally across multiple panels 5. As with the bulging suppression device 13 of the second embodiment, the upper and lower external seismic damping members 17a, 17b are installed on the outer surface of the side plate 14 via a mounting frame 18.

[0039] In the bulging suppression device 33 of the fourth embodiment, four external vibration damping members 17a are connected to each other via four corner members 19a to form a frame shape. The corner members 19a and the external vibration damping members 17a are joined by welding, bolts, or the like. To prevent deformation of the side plate 14, a cushioning material such as rubber may be interposed between the external vibration damping members 17a and the side plate 14. Similarly, the four lower external vibration damping members 17b are connected to each other via four corner members 19b to form a frame shape.

[0040] The force with which the frame-shaped external vibration damping members 17a, 17b fasten the side panel 14 may be adjustable. For example, by providing a slot or the like similar to that in the first embodiment at the connecting portion of the external vibration damping members 17a, 17b, the force with which the side panel 14 is fastened can be adjusted.

[0041] The bulging suppression device 33 of the fourth embodiment provides the same effects as the bulging suppression device 13 of the second embodiment.

[0042] The present invention is not limited to the above-described embodiment, and can be embodied in other embodiments without departing from the spirit of the present invention.

[0043] For example, in the bulging suppression device 3 of the first embodiment, the four external vibration damping members 7 are not joined to one another, but the four external vibration damping members 7 may be joined to one another to form a frame shape. This provides the same effects as the bulging suppression devices 13 and 23 of the second and third embodiments.

[0044] Furthermore, in the bulging suppression devices 13, 23, and 33 of the second, third, and fourth embodiments, the four corners of the above-ground rectangular water tanks 11 and 20 may be held down with structural steel such as L-shaped steel extending vertically from the outside for further earthquake reinforcement, and the four external seismic damping members 17a and 17b may be connected to each other via these structural steel. [Explanation of symbols]

[0045] 1, 11, 20...Above-ground rectangular tank 3, 13, 23, 33...Bulging suppression device 4,14...Side panel 5...Panel 5a...Substrate 5b...Connection flange 7, 17a, 17b...External vibration control members

Claims

1. an external vibration control member disposed on an outer surface of a side panel having a plurality of panels arranged vertically and horizontally, the external vibration control member extending horizontally across the plurality of panels; A bulging suppression device for an above-ground rectangular water tank, in which the side panel is divided into upper and lower parts by the external seismic damping member.

2. the external vibration control members are installed on the outer surfaces of the four side panels of the above-ground rectangular water tank; The bulging suppression device according to claim 1, wherein the four external vibration suppression members are connected to each other to form a frame shape.

3. 3. A bulging suppression device according to claim 1, wherein the force with which the external vibration suppression member tightens the side plate in the perpendicular direction is adjustable.

4. 3. The bulging suppression device according to claim 1, wherein the external vibration damping member is installed at a joint between the panels positioned vertically.

5. 3. The bulging suppression device according to claim 1, wherein the joining flange of the panel is bent from the base plate of the panel toward the inside of the water tank.

6. an external vibration control member extending horizontally across the plurality of panels is installed on the outer surface of the side panel having the plurality of panels arranged vertically and horizontally; A bulging suppression method for an above-ground rectangular water tank, in which the side panel is divided into upper and lower parts by the external seismic damping member.

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