JP2538846B2 - Damping method for existing structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a). BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping method capable of suppressing vibration caused by wind, earthquake, etc. in an existing structure having an elevated water tank.

(B). 2. Description of the Related Art Recently, in structures such as an observation tower, a super high-rise house, and a high-rise office building, which have a relatively long primary natural vibration period of a flexible structure, the vibration energy of the structure near the top of the structure It has been attempted to install a vibration damping device to absorb the vibration and reduce the sway of the structure caused by wind or earthquake.

(C). Problems to be Solved by the Invention Most of these vibration damping devices are composed of a large-scale mechanical device that swings a balance weight, and installation on an existing structure requires installation, installation space, etc. It has many problems.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vibration control method for an existing structure that can be easily installed on the existing structure without using a complicated mechanical device in order to solve the above-mentioned drawbacks. To do.

(D). Means for Solving the Problems That is, according to the present invention, in an existing structure (1, 6) provided with an elevated water tank (5) having a lid (5g) on the upper part thereof, a resistance member (5c) is added to the elevated water tank. , 5d, 5e), and a wave canceling device (5h) made of a block-shaped porous member on both sides of the upper part of the elevated water tank, and stored in the resistance member and the elevated water tank. The resistance generated between the water (5b) suppresses the vibration generated in the existing structure, and when the water in the elevated water tank largely shakes, the water disperses and flows into the inside of the porous member. , So as to prevent the water from splashing back from the lid.

It should be noted that the numbers in parentheses indicate the corresponding elements in the drawings for the sake of convenience, and thus the present description is not limited to the description in the drawings. The same applies to the section "(e). Action" below.

(E). Action Due to the above-described configuration, the present invention provides the existing structure (1,
By installing the resistance member (5d, 5e) in the elevated water tank (5) of 6), the elevated water tank (5) is an existing structure (1, 6).
Acts as a vibration control means.

Further, the present invention acts so that the wave-eliminating device (5h) prevents the water (5b) from directly colliding with the lid to prevent the fluctuation of the swing of the water (5b).

(F). Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an example of an existing structure to which the present invention is applied, FIG. 2 is a perspective view showing an installation mode of an elevated water tank, and FIG. 3 is a plan view showing an example of an elevated water tank with meshes installed. FIG. 4 is a front sectional view of the elevated water tank of FIG. 3, FIG. 5 is a plan view showing another installation mode of meshes in the elevated water tank, and FIG. 6 is a front sectional view of the elevated water tank of FIG. FIG. 7 is a plan view showing another installation mode of the resistance member to the elevated water tank, FIG. 8 is a front sectional view of the elevated water tank of FIG. 7, and FIG. 9 is another installation mode of the mesh to the elevated water tank. FIG. 10 is a front view showing another example of an existing structure to which the present invention is applied.

As shown in FIG. 1, the super high-rise building 1 which is an existing structure has a structure 3 standing upright on the ground 2. The top 3a of the structure 3 is used for domestic water, fire water, etc. The elevated water tank 5 used is installed. As shown in FIG. 2, for example, two elevated water tanks 5 are installed so as to intersect each other at right angles, and each elevated water tank 5 has a lid 5g at the top, as shown in FIG. 3 and FIG. Has a water tank 5a having a rectangular planar shape. Each water tank 5a stores water 5b such as domestic water and fire fighting water.

Since the existing super high-rise building 1 has the above-mentioned configuration, in order to impart damping properties to such a structure, stainless steel, vinylon, high Mesh as damping member made of high performance fiber
In FIG. 4, two meshes 5c are provided on the upper and lower sides, and a mesh 5c is installed at the center of the water tank 5a so as to divide the water tank 5a into right and left. Also, at the top of the water tank 5a, on both sides of the lid 5g, iron scraps,
Construction will be performed to provide wave-dissipating devices 5h, 5h composed of a porous member in which crushed stones, metal chips, etc. are formed in block strips.

In this state, when the structure 3 shakes due to an earthquake or a strong wind, the elevated water tank 5 installed on the top 3a also shakes. Then, the water 5b in the elevated water tank 5 swings in the longitudinal direction WD of the water surface 5f in synchronization with the vibration of the structure 3 as shown in FIGS. 3 and 4. That is, the rocking cycle of the water 5b (the rocking cycle of the water 5b is determined by the length L1 of the water tank 5a in the long side direction and the liquid height L3 of the water 5b in a stationary state, as shown in FIGS. 3 and 4. By adjusting the water level at all times so as to match the primary natural vibration period of the super high-rise building 1,
The water 5b easily starts oscillating due to the vibration of the super high-rise building 1, and the vibration absorbs the vibration energy of the super high-rise building 1. When the water 5b swings, the swing causes the water 5b to
As shown in AR, the mesh 5c installed in the water tank 5a,
The viscous resistance acting between the water 5b and the mesh 5c at that time acts in the direction of limiting the movement of the water 5b. As a result, the swing of the water 5b is damped, and the ability to absorb vibration energy is improved.

Further, when the vibration of the structure 3 exceeds a predetermined value, the wave height of the water 5b in the vibration damping device 5 also increases, and as shown in FIG. 4, the top 5j of the wave 5i reaches the lid 5g. Become. However, when the top 5j of the wave hits the lid 5g directly and bounces back,
Disturbance occurs in the cycle of the water 5b, making it impossible to exert an appropriate vibration damping effect. However, the aquarium where the top 5j of the wave 5i occurs
Wave canceling devices 5h, 5h are installed on both sides of the wave direction of 5a, and the wave 5i collides with the wave canceling device 5h.
It flows into the numerous pores of the porous member within 5h in a distributed form, its energy is effectively absorbed, and waves due to rebound that disturb the wave cycle in the tank do not occur. Furthermore, when the waves hit the lid 5g directly, the lid 5g
It is also possible to prevent the lid portion 5g from being deformed due to an excessive pressure generated in the. Therefore, the vibration absorbing operation of the elevated water tank 5 is smoothly performed.

Although the above-mentioned embodiment has described the case where the mesh 5c is used as the resistance member provided in the water tank 5a, as the resistance member, as long as it can damp the swing of the water 5b in the water tank 5a, Such a shape, shape, or any installation mode may be used. For example, as shown in FIGS. 5 and 6, a plurality of meshes 5c are formed by dividing the water tank 5a in the vertical direction of FIG. May be installed. Further, as shown in FIG. 9, it is of course possible to provide the mesh 5c in a combination of the vertical and horizontal directions of the water tank 5a.

In addition to the mesh 5c, for example, FIGS.
As shown in the figure, in the water tank 5a, the partition wall 5d is provided in the wave direction of the water 5b, that is, in the form of being divided in the left-right direction in the figure (the water surface 5f is divided into a plurality), and a large number of projections 5e are formed on the partition wall 5d. The water 5b is planted in a shape adapted to the swinging form of the water 5b (that is, in a shape in which the central portion is recessed as shown in FIG. 8, for example), and the water 5b is formed by viscous resistance generated between the projection 5e and the water 5b. Of course, it is also possible to damp the vibration of. Furthermore, steel chips,
It is also possible to install a plastic molded product or the like in the water tank 5a as a damping member.

Further, as an existing structure to which the present invention is applied, a flexible structure having an elevated water tank 5 at the upper part and a relatively long vibration cycle is suitable, and other structures such as the super high-rise building 1 as shown in FIG. Needless to say, the present invention can be applied to, for example, the tower 6 made of steel or the like as shown in FIG.

As the amount of water 5b in the water tank 5a, the free water weight that contributes to the rocking is 0.5 to 2% of the weight of the structure (the larger the free water weight, the higher the vibration damping effect), and the damping constant of the resistance member. Is about 2 to 10%, it is possible to exert a vibration damping effect.

Further, in the above-mentioned embodiment, the case where the wave canceling device 5h is provided on both sides of the water tank 5a in the wave direction WD is described.
It is of course possible to provide not only on both sides of the water tank 5a but also on the entire upper surface or the entire side wall of the water tank 5a.

(G). EFFECTS OF THE INVENTION As described above, according to the present invention, in an existing structure such as a super high-rise building 1 or a tower 6 in which an elevated water tank 5 having a lid such as a lid 5g is provided in the upper portion, The mesh 5c, the partition wall 5d, the resistance member such as the protrusion 5e is installed in the water tank, and the wave-eliminating device 5h made of a block-shaped porous member is installed on both upper sides of the elevated water tank, and the resistance member Due to the resistance generated between the water 5b stored in the elevated water tank, the vibration generated in the existing structure is suppressed, and when the water in the elevated water tank is largely shaken, the Since water is dispersed and inflowed and is configured to be able to prevent the water from splashing back from the lid, the elevated water tank 5 provided in the existing structure such as the super high-rise building 1 and the tower 6.
It is possible to add a damping function against vibrations caused by wind and earthquakes simply by installing a resistance member inside. Further, since there is no complicated mechanical device installation work, the installation is easy, and since the existing elevated water tank 5 is used, no special installation space is required and the installation is easily performed on existing structures. You can

Further, even if a large-amplitude swing occurs in the elevated water tank by the wave-eliminating device, the swing can be dispersed and flowed into the porous member to absorb the energy so that the water directly collides with the lid. It can be prevented. Therefore, it is prevented that the rocking water directly collides with the lid, and thus the lid is deformed or the water colliding with the lid bounces and disturbs the rocking cycle of water. However, the damping performance can be sufficiently exhibited, and it becomes possible to provide a highly reliable damping device.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an existing structure to which the present invention is applied, FIG. 2 is a perspective view showing an installation mode of an elevated water tank, and FIG. 3 is a plan view showing an example of an elevated water tank with meshes installed. FIG. 4 is a front sectional view of the elevated water tank of FIG. 3, FIG. 5 is a plan view showing another installation mode of meshes in the elevated water tank, and FIG. 6 is a front sectional view of the elevated water tank of FIG. FIG. 7 is a plan view showing another installation mode of the resistance member to the elevated water tank, FIG. 8 is a front sectional view of the elevated water tank of FIG. 7, and FIG. 9 is another installation mode of the mesh to the elevated water tank. FIG. 10 is a front view showing another example of an existing structure to which the present invention is applied. 1 …… Existing structure (super high-rise building) 5 …… Elevated water tank 5b …… Water 5c …… Resistance member (mesh) 5d …… Resistance member (partition wall) 5e …… Resistance member (projection) 5g …… Lid (lid) Body) 5h …… Wave-eliminating device 6 …… Existing structure (tower)

Continuation of the front page (56) References Japanese Patent Laid-Open No. 63-40064 (JP, A)

Claims (1)

(57) [Claims] 1. An existing structure having an elevated water tank having a lid on an upper portion thereof, wherein a resistance member is installed in the elevated water tank, and block-shaped porous members are provided on both sides of an upper portion of the elevated water tank. The wave breaker is installed, and the resistance generated between the resistance member and the water stored in the elevated water tank suppresses the vibration generated in the existing structure and causes the water in the elevated water tank to largely shake. A method for damping vibration in an existing structure configured to prevent the water from splashing back from the lid when the water disperses and flows into the porous member.