JP3463085B2 - Seismic building - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earthquake-resistant building having a structure excellent in earthquake resistance. 2. Description of the Related Art As is well known, as a structure for securing the seismic performance of a building, a structural structure that enhances the resistance against seismic force as a robust structure has been long and generally used. In, seismic isolation structures and seismic control structures have been proposed and put into practical use. The seismic isolation structure reduces the response by supporting the entire building with seismic isolation devices such as laminated rubber to reduce the seismic motion input to the building. The seismic isolation structure uses the seismic energy input to the building. Is controlled by a damping device such as a damper to absorb response. [0003] By the way, in the conventional general bearing structure, in order to increase the resistance to seismic force, the cross-section of structural members such as columns and beams is inevitably increased, resulting in high rigidity and short period. This results in a vicious cycle in which the seismic force input to the building increases and the member cross section further increases. On the other hand, in the conventional seismic isolation structure, the seismic input to the building is greatly reduced and the acceleration response is sufficiently small, but the displacement response is large. Since the foundation needs to have a double structure for installation, an increase in construction cost is inevitable, and there is a problem that long-term maintenance is required for the seismic isolation device. Further, in the conventional vibration control structure, various dampers such as an oil damper, a viscous damper, a steel damper, and a friction damper are installed at important points of a building to absorb vibration energy and attenuate vibration. However, in the past, it was only enough to absorb a small part of the seismic energy, and it was not possible to sufficiently suppress the deformation of the building. It is a prerequisite to ensure the strength of the building. In view of the above circumstances, the present invention is intended to provide an effective earthquake-resistant building which can greatly improve the earthquake-resistant performance in place of the conventional load-bearing structure, seismic isolation structure, and vibration control structure. [0007] The earthquake-resistant building of the present invention comprises:
The first floor is made of pyro tea, and the span of the center of the tea is orthogonally crossed with a viscous shear wall that exerts a damping function due to its own viscous resistance when subjected to an earthquake load.
An earthquake-resistant building provided in two directions , wherein the viscous shear wall has high rigidity and high toughness, has a strength corresponding to an earthquake load, and a damping force exerted by the viscous shear wall has an overall strength of the building. While being set to be larger than the restoring force, the columns and beams constituting the skeleton of the building have only the proof stress corresponding to the long-term load acting on the building, and the viscous shear walls are spaced apart from each other. A viscous body or a viscoelastic body is sandwiched between at least a pair of steel plates laminated so as to be displaceable in a state where the viscous body or the viscoelastic body is adhered. The pair of steel plates are arranged in an enclosed space and fixed to the upper and lower beams, respectively. That is, in the earthquake-resistant building of the present invention, almost all of the seismic load is borne only by the viscous shear wall, and the damping force of the viscous shear wall sufficiently suppresses the vibration during the earthquake and hardly vibrates. Attenuation can be realized. Therefore, seismic loads are not applied to columns and beams, and those columns and beams having a small cross section that can bear only a long-term load are sufficient. An embodiment of the earthquake-resistant building according to the present invention will be described below. FIG. 1 is an elevation view showing an outline of the earthquake-resistant building of the present embodiment, and FIG. 2 is a plan view of the first floor. This earthquake-resistant building is a low-rise (six-story in the example shown) steel-frame building. The first floor is a piloti, and the center of the first floor functions as a damper during an earthquake. The viscous earthquake-resistant wall 1 which exerts a large damping force is arranged. As shown in FIGS. 3 and 4, the above-mentioned viscous earthquake-resistant wall 1 is installed in a space surrounded by columns 2 and beams 3 (3a, 3b). The steel plate 4a fixed to the upper beam 3b and the steel plate 4b fixed to the upper beam 3b are alternately laminated with a slight gap therebetween, and a viscous body 5 having a large viscous resistance is provided between the steel plates 4a and 4b. For example, it has a configuration in which rubber asphalt is sandwiched between both steel plates 4a and 4b in a state of being adhered thereto. Reference numerals 6a and 6b denote mounting plates fixed to the steel plates 4a and 4b, respectively.
Connects the steel plates 4a, 4b to the beams 3 through the mounting plates 6a, 6b.
An anchor for fixing to a and 3b. The viscous earthquake-resistant wall 1 having the above-mentioned structure has high rigidity and high toughness while being thin as a whole, and is nondestructively large-deformable and can be restored. For example, steel plates 4a and 4b having a thickness of 16 mm
In the case where rubber asphalt (viscosity of about 60,000 to 1,000,000 pois) having a thickness of 2 mm is sandwiched between them as the viscous material 5 by alternately stacking them, the total thickness is only 88 m.
m, it can have the same degree of rigidity as a reinforced concrete shear wall having a thickness of 500 mm, and reinforced concrete has an undesirably high toughness. In addition, since the viscous shear wall 1 has sufficiently high rigidity, its vibration characteristics naturally have a short period, and therefore its restoring force characteristics exhibit a vertically long loop, and the amount of energy absorption per unit time is extremely large. Becomes
Of course, the type of the viscous or viscoelastic material and the steel plates 4a, 4b
The damping force can be freely set by adjusting the number of stacked layers, their dimensions, and the like. In the building of the present embodiment having the above-described viscous shear wall 1, the damping force exerted by the viscous shear wall 1 during an earthquake is larger than the restoring force of the entire building, that is, It is set to be over damped,
As a result, the building can hardly vibrate even during an earthquake. In other words, the upper and lower beams 3a, 3
In the case where b causes interlayer displacement, the viscous damping wall 1 exerts an extremely large damping force and the two steel plates 4a and 4b are relatively displaced minutely (about 2 to 4 mm) in the plane. It can prevent the building from vibrating. As a result, this building does not resonate simply by performing the same motion with a predetermined phase difference from the ground motion even if it receives the seismic force, and therefore does not resonate. , All of the displacement is reduced, and the input energy is almost zero. Further, as described above, in this building, overdamping is realized by the damping force of the viscous shear wall 1, and the building can hardly vibrate even during an earthquake. It is not necessary for the structural members such as the beams 3 to take into account the resistance to seismic force. Therefore, the columns 2 and the beams 3 can be formed to have a small cross section enough to ensure the resistance to a long-term load. In other words, in this building, almost all of the seismic load is borne by the viscous shear wall 1, and therefore the structural members such as the columns 2 and the beams 3 need to bear only long-term loads. It is possible to significantly reduce costs and increase the effective indoor space by saving the cross section. If the structural member has a small cross section, its spring constant will be small and the mass of the building will be small, so that the building will be more easily damped.
This is advantageous in realizing overdamping. In addition, the reduction in the cross section of the column 2 or the beam 3 is the yield deformation (the elastic deformation limit).
Is large, and therefore, even if they undergo large deformation, they easily fall within the range of elastic deformation, which is also advantageous in this respect. Although the embodiments of the present invention have been described above, the present invention is not limited to the form, scale, application, and structural form of the building, and may be applied to S structures, RC structures, SRC structures and any other structures. It can be applied and can be widely applied from low-rise buildings including one-story buildings to high-rise buildings. Needless to say, the required number of viscous shear walls may be appropriately arranged at appropriate positions, and the configuration and form thereof may be appropriately changed as long as desired damping force, rigidity and toughness can be secured. In addition, the present invention is applicable not only to newly-built buildings, but also to the case of implementing seismic reinforcement of existing buildings, in which case, in addition to adding viscous shear walls to existing buildings, existing For columns and beams, it is sufficient to reduce the proof stress against seismic loads by, for example, thinning out some of them or modifying them to have small cross sections while maintaining the proof stress against long-term loads. As described above, the earthquake-resistant building of the present invention is
High rigidity and two directions Oite orthogonal span of the central portion of the high toughness of the viscous shear walls the first floor pilotis having a large damping force
Be placed, by setting larger than restoring force of the entire building its damping force, almost can be realized damping characteristics or overdamped as no to vibrate during an earthquake,
Since the seismic load is applied to the viscous shear walls and the long-term load is applied only to the columns and beams, the seismic building has excellent seismic performance, is structurally reasonable, and is cost-effective. Can be realized. In particular, the use of a viscous earthquake-resistant wall sandwiching a viscous or visco-elastic body between steel plates in a state of being adhered makes it possible to achieve high damping force, high rigidity,
A highly tough viscous shear wall can be easily obtained, and the damping force can be easily adjusted.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation view showing an embodiment of an earthquake-resistant building of the present invention. FIG. 2 is a plan view of the same. FIG. 3 is a side sectional view showing an example of a viscous shear wall. FIG. 4 is a front view of the same. [Description of Signs] 1 Viscous shear wall 2 Column 3 Beam 4a, 4b Steel plate 5 Viscous body

   ────────────────────────────────────────────────── ─── Continuation of front page       (56) References JP-A-9-144374 (JP, A)                 JP-A-5-33525 (JP, A)                 JP-A-8-338153 (JP, A)                 JP-A-6-212833 (JP, A)                 JP-A-64-29583 (JP, A)                 JP-A-1-154970 (JP, A)

Claims (1)

(57) [Claims] [Claim 1] The first floor is made of a pyro tea, and the span at the center of the pyro tea is minutely deformed by its own viscous resistance when subjected to an earthquake load to have a damping function. An earthquake-resistant building provided with viscous shear walls to exert in two orthogonal directions , wherein the viscous shear walls have high rigidity and high toughness, have a strength corresponding to an earthquake load, and exhibit the viscous shear walls. While the damping force is set to be larger than the restoring force of the entire building, the columns and beams constituting the skeleton of the building have only the proof stress corresponding to the long-term load acting on the building, The wall is configured such that a viscous body or a viscoelastic body is sandwiched between at least a pair of steel plates laminated so as to be relatively displaceable at intervals, and the viscous earthquake-resistant wall is located at a central portion of the first floor. Columns and beams in the span of Ri seismic buildings characterized by comprising fixed each steel plate of the pair disposed in the space to the upper and lower beams enclosed.