JP4749599B2 - Damping structure of structures with large spaces - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vibration control structure for suppressing vibration of a structure having a large space.
[0002]
[Prior art]
Examples of the structure having a large space include a baseball field and a stadium having a track for soccer and athletics. A structure having such a large space cannot be provided with a pillar or the like inside the large space due to its character. For this reason, in a dome-like baseball field or the like, the support span of the dome-like roof becomes very large. Similarly, in stadiums and the like, a large roof is installed on the upper part of the spectator seat, and this large roof often has a cantilever structure.
[0003]
[Problems to be solved by the invention]
It is well known that such a large-span dome-shaped roof or a cantilevered large roof structure is disadvantageous against vibrations caused by wind or earthquake. Not only the above-mentioned dome roof and cantilevered large roof, but also structures with large spaces, a structure with a large span is built around the large space (not only horizontally but also vertically). It has a structure part that is disadvantageous to vibration caused by earthquakes. Under such circumstances, there has been a demand for more effective seismic control in structures with large spaces.
[0004]
An object of the present invention is to provide a vibration control structure capable of effectively performing vibration control in a structure having a large space.
[0005]
[Means for Solving the Problems]
The invention according to claim 1 dampens a structure having a large space and hollow structural members arranged in a lattice shape around the large space, and is provided for a node portion where the hollow structural members intersect . It is characterized by a built-in tuned mass damper.
[0006]
The invention described in claim 2 is characterized in that, in the invention described in claim 1, the hollow structural member is a roof frame that covers the large space from above.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a structure (large dome structure) having a large space to which an embodiment of the present invention is applied. FIG. 2 is a side view of the node portion (node) of the dome structure incorporating the vibration control mechanism.
[0008]
As shown in FIG. 1, the large dome 1 in which the vibration control structure of the present embodiment is incorporated has a basic skeleton structure in which hollow round steel pipes (hollow structure members) 2 are constructed in a lattice shape. And the center part of the basic skeleton structure becomes a raised shape, and a dome-like form is constructed. Although not shown, a film is stretched on the top of the dome 1, and the dome 1 itself is installed as a roof on the top of the baseball field.
[0009]
The dome 1 is supported only around the basic skeleton structure described above, and the central portion of the basic skeleton structure is not supported from below. The hollow round steel pipe (hollow structure member) 2 constituting the basic skeletal structure mainly includes cross-shaped steel pipes arranged at the nodes of the basic skeletal structure (see FIG. 2; hereinafter, this crossed shape). There are two types of steel pipes: a slightly curved steel pipe that connects the node parts 3 to each other. The latter steel pipe is slightly curved according to the shape of the dome 1. In addition, although the damping mechanism mentioned later is incorporated in the inside of the node part 3 shown by FIG. 2, it does not necessarily mean that the damping mechanism is incorporated in all the node parts 3. FIG.
[0010]
A flange 3a is formed at each end of the intersecting steel pipe (node part 3) and a slightly curved rod-shaped steel pipe, and the flanges 3a are fastened with bolts and nuts. The dome 1 of this embodiment is used as a roof of a baseball field, and each steel pipe has a diameter of about 2 m.
[0011]
And the passive damping mechanism which consists of a mass-spring system shown by FIG. 2 is incorporated in the arbitrary places of the lattice-shaped hollow steel pipe mentioned above. In the present embodiment, the vibration control mechanism is incorporated in the node portion 3, but may be incorporated in a rod-shaped hollow steel pipe. When incorporating a vibration control mechanism, the position and number of effective vibration control are determined in advance by structural analysis of the basic skeleton structure. Also determine the natural frequency of each seismic control mechanism.
[0012]
The vibration control mechanism is a tuned mass damper (TMD) and includes a weight 4 and a spring 5. The tuned mass damper has a structure composed of a mass-spring system, and the natural frequency of the mass-spring system is synchronized with the natural frequency of the structure to be installed. By installing such a tuned mass damper, the vibration energy of the structure can be absorbed and the vibration of the structure can be reduced.
[0013]
One end of a plurality of springs 5 is attached to the weight 4, and the other end of each spring 5 is attached to the inner surface of a steel pipe that becomes the node portion 3. Accordingly, the weight 4 is in a state of floating inside the node unit 3. The spring used in this mass-spring system may be a rubber member such as laminated rubber, or a metal spring, etc., as long as it can function as a mass-spring system spring. Anything can be used.
[0014]
Moreover, after the structure is finally assembled, vibration analysis is performed on the ground, and the tuning of each vibration control mechanism (tuned mass damper) is adjusted again based on the result. In this case, the node part 3 of the corresponding part may be temporarily removed, and re-tuned and then reattached. According to the vibration control structure of the present embodiment, vibration control can be effectively performed even in a structure having a large space. Further, since the tuned mass damper is incorporated in the hollow structural member, it is not noticeable in appearance and is very excellent in terms of design.
[0015]
Furthermore, since the tuned mass damper is incorporated in the hollow structural member, there is very little risk of causing a change in performance due to long-term exposure to sunlight or wind and rain. Moreover, since deterioration can also be suppressed, it is advantageous from the viewpoint of durability.
[0016]
In addition, this invention is not limited to embodiment mentioned above. For example, although the above-described embodiment applies the vibration control structure of the present invention to a dome roof of a baseball field, the present invention can also be applied to other structures. For example, the present invention may be applied to a cantilevered large roof such as a stadium. In this case, the pillar supporting the roof may be a hollow structural member, and a tuned mass damper may be incorporated in the inside.
[0017]
Alternatively, when a large atrium space such as an atrium is formed inside a building, the vibration control structure of the present invention is applied to a hollow structural member disposed on the ceiling, side wall, or floor of the large space. Good. Alternatively, the seismic damping structure of the present invention may be applied to a hollow structural member constituting a truss when a large-span skeleton structure is constructed with the truss.
[0018]
【The invention's effect】
According to the present invention, since the vibration control effect by the tuned mass damper can be obtained effectively, excellent vibration control can be performed. Moreover, since the tuned mass damper is disposed in the hollow structural member, the tuned mass damper is not visible from the outside, and is very advantageous from the viewpoint of design. In addition, the tuned mass dampers can be installed in a plurality of locations, and it is easy to make adjustments that can surely obtain the effect of the vibration control. Furthermore, by installing a tuned mass damper in the hollow structural member, it becomes easier to deal with vibration in three dimensions rather than dealing with vibration in a two-dimensional plane.
[0019]
Furthermore, according to the vibration control structure of the present invention, it is possible to reduce the thickness of the above-described hollow structure material due to the vibration control effect. For this reason, the seismic damping structure of the present invention contributes to the reduction of raw materials and also improves the workability by reducing the weight of the structural material, and thus contributes to the shortening of the construction period.
[0020]
In the case of a large roof such as the above-described stadium or baseball stadium, a swirling wind or the like inside the stadium or the like often blows from below, which is disadvantageous in terms of vibration. The vibration control effect is very effective. In these structures, because of the nature of the structure, a necessary roof span is increased, or a large roof is supported by a cantilever, so that the vibration control effect according to the present invention is very effective.
[0021]
In addition, since the weight of the roof portion is reduced, there is an advantage that the burden on the lower structure can be reduced (the lower structure can be reduced in cross section). Further, a suspended object such as a speaker is often installed from the roof portion of the large space, but if the present invention is applied to the roof portion of such a large space, it is advantageous in terms of vibration control.
[Brief description of the drawings]
FIG. 1 is a schematic view of a structure (large dome structure) to which a vibration control structure of the present invention is applied.
FIG. 2 is a side view of a node portion (node) incorporating the vibration control mechanism of the dome structure shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Dome (structure), 2 ... Hollow round steel pipe (hollow structure member), 3 ... Node part, 4 ... Weight of tuned mass damper, 5 ... Spring of tuned mass damper.

Claims (2)

In the vibration control structure of a structure having a large space and hollow structural members arranged in a lattice pattern around the large space,
A damped structure for a structure having a large space, wherein a tuned mass damper is built in a node portion where the hollow structural members intersect .   2. The vibration control structure for a structure having a large space according to claim 1, wherein the hollow structural member is a roof frame that covers the large space from above.

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