JPH0756187B2 - Vibration suppression device for structures - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vibration suppression device for a structure that suppresses vibration caused in a structure by an earthquake, wind, or the like.

"Conventional technology" Due to factors such as the development of high-strength materials, advances in machining technology, and the development of structural analysis technology using computers, recent structures are becoming larger, diversified in form, and lighter in weight. , The structure is becoming more flexible. And in such a light and flexible structure, the natural frequency tends to be low and the vibration damping tends to be small.
In particular, various unexpected vibrations may occur due to the influence of aerodynamic external force due to wind.

Therefore, for the purpose of cutting off this type of vibration source, it is conceivable to take aerodynamic measures on the outer shape of the structure, but the outer shape of the structure has restrictions from the functional or design viewpoint, It is difficult to rely solely on this aerodynamic measure.

Therefore, in order to solve the above problems by means other than aerodynamic measures, it is also considered to suppress the vibration generated in the structure by damping it. There is one disclosed in JP-A-60-241045 (JP-A-62-101764). This vibration suppressing device is provided with a tank for storing a liquid that vibrates at a required position of a structure at the same cycle as the unique vibration cycle of the structure and with a phase difference. It suppresses the rolling of the.

In addition, as a modification of this vibration suppression device,
There is a device disclosed in JP-A-63-184922. In this vibration suppressing device, an adjusting member for damping the vibration of liquid in the tank is protruded from the inner surface of the tank. Is provided to suppress not only the vibration of the structure but also the swinging rotation.

[Problems to be Solved by the Invention] By the way, in the case of suppressing the vibration and swinging rotation of a structure by the vibration suppressing device as described above, this vibration suppressing device is applied to a rooftop when constructing a structure. Need to be installed. However, since a large tank is required to obtain a sufficient vibration suppressing effect, this tank occupies a large space, and such a large space cannot be used for purposes other than vibration suppression. There is a problem that the limited space of the structure cannot be effectively used.

It is also conceivable to use the tank of this vibration suppression device as a water storage tank for drinking water, but in order to fully exert the damping effect in this vibration suppression device, keep the water level in the tank constant at all times. I have to go. However, since the amount of drinking water used is not constant, when the above tank is used as a water storage tank for drinking water,
There is a problem that it is difficult to keep the water level constant at all times, and if the water is stored for a long time to keep the water level constant, the water in the tank will not be suitable as drinking water. .

The present invention has been made in view of the above problems, and an object of the present invention is to use the vibration suppressing device as other equipment necessary for a structure.

"Means for Solving the Problems" The present invention relates to a tank provided in a structure, in which a liquid vibrating in the same natural vibration cycle as the natural vibration cycle of the structure is stored, and The tank has a space that allows the vibration of the liquid above the liquid surface of the liquid in a stationary state, and a plurality of adjusting members for adjusting the attenuation of the liquid are provided inside the tank so as to project from the inner surface of the tank. A vibration suppressing device for a structure, wherein the adjusting member is composed of a heater or a heat exchanger, and an inlet / outlet for allowing the liquid in the tank to flow in and out is provided, and the liquid is used as a heating / cooling heat medium for the structure. It was done.

"Operation" In the vibration suppressing device for a structure of the present invention, a tank is provided at a predetermined position of the structure, and inside the tank,
With the same natural vibration cycle as the natural vibration cycle of the above structure,
And a liquid that vibrates with a phase difference and vibration peculiar to the structure is stored, and a plurality of adjusting members that adjust the attenuation of the liquid are provided inside the tank by projecting from the inner surface of the tank. When a structure vibrates due to an earthquake, wind, etc., the liquid stored in the tank vibrates in the same cycle as the structure's vibration cycle and in a phase-shifted state, suppressing vibration centering on the rolling of the structure. With the earthquake,
When the structure swings due to wind or the like, the liquid that moves in the circumferential direction of the tank due to the swinging rotation is subject to resistance by the adjusting member, and a turbulent flow is generated to suppress the swinging rotation.

Further, the vibration suppressing device is cooled and heated by forming the adjusting member from a heater or a heat exchanger and providing an inlet / outlet through which the liquid in the tank flows in and out, and by using the liquid as a heat medium for cooling / heating the structure. Heating medium heating tank,
It can also be used as a cooling tank to effectively use the limited space of the structure.

[Embodiment] A first embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

The vibration suppressing device of this embodiment has a structure in which the tank 1 for suppressing vibration is provided on the rooftop of a building which is said to be most effective against vibration caused by wind.

The tank 1 is a cylindrical container made of concrete with an upper part hermetically sealed, and a heat insulating material is embedded in the wall portion thereof, or the wall portion is made of concrete having high heat insulating performance. A liquid W, such as water, is stored inside the tank 1, and the height H of the liquid surface is the inner diameter of the tank 1 so that the liquid W vibrates in the same natural vibration cycle as the natural vibration cycle of the building. It is uniquely determined based on R. The tank 1 has a space above the liquid surface of the liquid W in a stationary state to allow the vibration of the liquid W, and a plurality of adjusting members 2 in contact with the side walls of the tank 1 are provided on the peripheral portion of the bottom surface of the tank 1. It is provided. These adjusting members 2
Are formed so as to be submerged in the liquid W stored in the tank 1, are spaced apart from each other by a predetermined distance along the circumferential direction of the tank 1, and are each radially from the center of the bottom surface of the tank 1. It is formed so as to extend. Further, an adjusting member 3 having the same size as the adjusting member 2 is formed inside the bottom surface of the tank 1 so as to radially extend from the center of the tank 1, and the center portion of the bottom surface of the tank 1 is also radially provided. An adjusting member 4 that extends is formed. The adjusting members 2, 3, 4 are each composed of a heater, and each of them is connected to the power source 5. That is, the adjusting members 2, 3 and 4 also serve to heat the liquid W. Further, an outlet port 6 for letting out the liquid W in the tank 1 is formed at the bottom of the tank 1,
An outflow pipe 7 is connected to the outflow port 6 for supplying the liquid W flowing out from the outflow port 6 to various parts of the building to heat the inside of the building. Further, an inflow port 8 is formed at an upper portion of a side wall of the tank 1, and an inflow pipe 9 for allowing the liquid W supplied to various parts of the building by the outflow pipe 7 to flow into the tank 1 at the outflow port 8. Are connected to each other, and the outflow amount of the liquid W flowing out from the outflow port 6 and the outflow amount flowing in from the inflow port 8 are maintained at the same amount, so that the height H of the liquid surface in the tank 1 is kept constant. I am trying.

According to the vibration suppressing device having such a structure, since the liquid level of the liquid W stored in the tank 1 is set to a height such that it has the same natural vibration period as the natural vibration period of the building, The vibration of the building caused by the wind can be suppressed. In addition, when the building swings due to the deviation between the center of gravity and the center of gravity of the building, the tank 1
The liquid W inside tries to flow in the circumferential direction of the tank 1, but in this case, since the adjusting members 2, 3, 4 act as flow resistance of the liquid W, the liquid W has the same cycle as the swing cycle of the building. , And the liquid W flows in the circumferential direction of the tank 1 in a phase-shifted state, and the liquid W suppresses swinging rotation. Therefore, both rolling and swinging can be suppressed.

Further, according to the vibration suppressing device for a building, since the wall of the tank 1 is made of a heat insulating material and the upper part thereof is sealed, the tank 1 can be used as a heat storage tank,
Moreover, since the adjusting members 2, 3 and 4 in the tank 1 are composed of heaters, not only the liquid W in the tank 1 can be heated but also heated. Further, the tank 1 is provided with an outlet 6 for letting out the liquid W in the tank 1, and the liquid W flowing out from the outlet 6 is supplied to various parts of the building by the outlet pipe 7. The tank 1 occupying the space can be effectively used. Then, after the supplied liquid W circulates throughout the building, it is returned to the tank 1 by the inflow pipe 9,
The outflow amount from the outflow port 6 and the inflow amount from the inflow port 8 are maintained at the same amount, so that the height H of the liquid surface in the tank 1 can be kept constant.

By the way, the liquid W stored in the tank 1 needs to generate vibrations out of phase with the same cycle as the cycle of the building. Therefore, the tank 1 without the adjusting members 2, 3, and 4
In the case of using, since the damping rate for the vibration of the liquid W itself is small, the effect of vibrating may be brought on the contrary unless a liquid having a viscosity higher than that of water is used. However, in the structure of the present invention, the damping rate of the liquid itself stored in the tank 1 can be adjusted by adjusting the width, size, and number of the adjusting members 2, 3, 4 when applied to any building. Can be adjusted, and therefore the damping rate of the entire structure can also be adjusted. It is estimated that the width of each adjusting member 2 should be about 5 cm in the tank 1 having a diameter of about 30 m.

FIG. 6 is a diagram showing a second embodiment of the present invention.

In the vibration suppressing device of this embodiment, the tank 1a installed on the roof of the building also has a role of heating the liquid W therein, and a heat storage tank 10 is provided in the basement of the building.
The liquid W heated in the tank 1a is stored in the heat storage tank 10
The liquid W is stored and kept warm, and the liquid W is supplied to various parts of the building as needed.

In this vibration suppressing device, since the liquid W flowing out from the tank 1a does not directly return to the tank 1a, the adjusting member 2a is provided with a liquid level holding mechanism in order to keep the liquid level in the tank 1a constant. Has been. The adjusting member 2a is set to have the same dimension as the height H of the liquid surface such that the height of the adjusting member 2a is the same as the vibration period of the building, and the shape thereof is formed into a cylindrical shape, and the upper end thereof is formed. From outlet 6a to tank
By flowing the liquid W in 1a to the outflow pipe 7, the tank
The liquid level is kept constant in 1a. The adjusting member 2a is composed of a heater, but the adjusting member 2a may not be composed of a heater, and another adjusting member composed of a heater may be provided.

In these vibration suppressing devices, the adjusting member is composed of a heater to heat the liquid in the tank, but the adjusting member may be composed of a heat exchanger. In this case, the heat of the heat medium can be transferred to the liquid in the tank by the heat exchanger to heat the liquid, and the liquid in the tank can be cooled by using the refrigerant. The liquid in the tank can also be used to cool the building.

The vibration analysis of the building and the tank performed in the specification of Japanese Patent Application No. 60-241045 (Japanese Patent Laid-Open No. 62-101764) will be described below.

First, if an analysis is performed on a tank not provided with an adjusting member, this tank and the building exhibit vibration characteristics similar to the vibration model shown in FIG.

In the vibration model shown in FIG. 3, a spring 11A having a spring constant K ₀ supports an object 12A having a mass M _{0 and} a dashpot 13A having a damping rate h ₀ is added to the vibration system A (the vibration of a building). Model) and a vibration system B (a vibration model in a tank) in which a spring 11B having a spring constant K ₁ supports an object 12B having an effective mass M _{1 and} a dashpot 13B having a damping rate h ₁ is added. It is configured.

Then, in such a vibration system, when the vibration system A starts to vibrate due to an external force applied to the object 11A, the vibration system B becomes 1 /
Since vibration starts with a phase difference of 4 cycles, vibration system A
・ By matching the natural vibration period of B, the vibration system A
Vibration can be suppressed.

Here, the natural vibration period of the vibration system is And the natural vibration period T ₀ of the building is uniquely determined by the mass M ₀ and the spring constant K ₀ determined from the structural design point of view, the liquid stored in the tank In order to match the natural vibration period T ₁ of W with the above-mentioned T ₀ , the dimensions and capacity of the tank are set so that they match.

That is, according to the Hausner theory that holds for the behavior of the stored liquid in the tank, the free water effective mass (mass acting as a vibrating body) M ₁ that can move in the tank as shown in the illustrated example is It is given by the equation (2).

However, H ... the distance from the bottom of the tank to the water surface R ... the radius of the tank M ... the mass of the liquid actually stored in the tank, and the natural frequency ω of the stored liquid W (so-called sloshing specific The frequency) is given by the following equation (3).

Further, from the natural frequency ω, the natural vibration period T is obtained as shown in the following equation (4).

If, for example, R = 15 m H = 2 m M = 1414 t (M = 812 t from the equation 2) is substituted for each parameter, T = 11.1.
7 seconds.

Then, between the natural vibration period T ₁ of the liquid in the tank and the natural vibration period T ₀ of the building obtained by the above formula, T ₀ = T ₁ ……………… (5) Formula is established. As described above, each dimension and storage amount of the tank are set.

The characteristics shown in FIGS. 4 and 5 were obtained from the experimental results of the displacement response magnification excited by the vibrating table. Fourth
The figure shows the result of an experiment carried out with the liquid (water) stored in the tank, and FIG. 5 shows the result of the experiment carried out with the tank being empty.

That is, the vibration can be suppressed as shown in FIG. 5 by providing a tank in a building having a large amplitude at a frequency close to the natural frequency and storing the liquid as shown in FIG.

Further, as a result of the experiment, it is effective when the ratio of the effective mass M ₁ of the liquid W and the mass M of the building ₁ is set to M ₁ / M = 1/50 to 1/100 (6) It was possible to exert the vibration suppression effect. Here, if the effective mass is 1/100 or less, a sufficient vibration damping effect cannot be obtained, and if it is 1/50 or more, the liquid may cause the vibration effect to the contrary. Since it is necessary to perform this, it is better to set the ratio of M to M ₁ as in the above equation (6).

The shape of the tank is not limited to the cylindrical shape as shown in the above-mentioned embodiment, but may be a plane quadrangle, a sphere, a plane ellipse, or the like.
You may change into various shapes according to installation conditions. In this case, the Hausner's theory may be applied to set the vibration period and the mass based on an equation corresponding to the shape.

[Advantages of the Invention] According to the vibration suppressing device for a structure of the present invention, the adjusting member provided so as to project from the inner surface of the tank is constituted by a heater or a heat exchanger, and an inlet / outlet for letting the liquid in the tank flow in and out Since the liquid is used as the heating / cooling heat medium for the structure, vibration of the structure, swinging, etc. can be suppressed, and this vibration suppressing device can be used as a heating tank for the heating / cooling heat medium, a cooling tank, etc. Can also be used. Therefore, it is possible to effectively use the limited space of the structure, and when constructing the structure equipped with the cooling and heating equipment and the vibration suppressing device, the construction can be simplified and the total construction cost can be reduced. Can be kept low with.

[Brief description of drawings]

1 and 2 are views showing a first embodiment of the present invention, FIG. 1 is a schematic configuration diagram of a vibration suppressing device, and FIG. 2 is a plan view of a tank. Figure 3 shows the vibration model of the building,
FIG. 4 is a displacement response magnification diagram of the tank of the present invention, and FIG. 5 is a displacement response magnification diagram of an empty tank. FIG. 6 is a schematic configuration diagram of a vibration suppressing device according to a second embodiment of the present invention. W: Liquid, 1 ... Tank, 2, 3, 4 ... Adjusting member,
6 ... Outlet, 8 ... Inlet.

Claims (1)

[Claims] 1. A liquid tank vibrating at a natural vibration cycle identical to the natural vibration cycle of the structure is stored inside a tank provided in the structure, and the tank is filled with the liquid of the liquid in a stationary state. A vibration suppressing device for a structure, which has a space for allowing vibration of liquid above the liquid surface, and wherein a plurality of adjusting members for adjusting the attenuation of the liquid are provided inside the tank so as to project from the inner surface of the tank. There is a structure characterized in that the adjusting member is composed of a heater or a heat exchanger, and an inlet / outlet for allowing the liquid in the tank to flow in and out is provided, and the liquid is used as a heating / cooling heat medium for the structure. Vibration suppression device.