JP2001132263A - Base isolation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base isolation building capable of efficiently displaying base isolation effect at a low cost. SOLUTION: A wall is not provided between columns 6 up to height corresponding to at least third-floor part from a foundation, a floor 7 constituting a first floor from the foundation is mounted on a beam 8 in a state that it is separated from the beam 8 and the column 6, and a damping device 11 is installed between the lower face of the floor 7 and the column 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation structure.

[0002]

2. Description of the Related Art In recent years, seismic isolation structures 24 and 25 as shown in FIGS. 6A and 6B have been constructed to protect buildings from vibrations caused by earthquakes. The seismic isolation structure 24 shown in the above (1) divides the base structure 26 and the upper structure 27 and concentrates the displacement of the building during an earthquake on a seismic isolation device 28 such as a seismic isolator installed between them. It is a thing. Also, as shown in FIG. 2B, a seismic isolation structure 25 including a high-rise section 29 and a low-rise section 30 is provided.
Is to separate the high-rise section 29 and the low-rise section 30 and join them with a damping device 31 such as a damping damper to reduce the amplitude during an earthquake or to absorb seismic energy.

[0003]

However, the above (1)
The seismic isolation structure shown in (1) requires a double floor plate above and below the seismic isolation device, and requires a rigid column on the seismic isolation device, resulting in high frame cost. Further, the seismic isolation device shown in (2) has a problem that if the high-rise portion does not have a sufficient height, a predetermined effect cannot be obtained without a noticeable difference in the natural period.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a seismic isolation structure capable of efficiently exhibiting a seismic isolation effect at low cost.

[0005]

Means for attaining the above object are as follows: the invention of claim 1 is at least 3
No wall is provided between the columns up to the height corresponding to the floor portion, and the floor constituting the first floor from the foundation is placed on the beams in a state where the floor is cut off from the beams and columns, and the lower surface of the floor and It is characterized in that a damping device is installed between the column and the pillar.

According to the first aspect of the present invention, the elongate columns extending from the foundation to at least the height corresponding to the third floor portion increase the natural period of the building and enhance the seismic isolation effect.

According to a second aspect of the present invention, in the first aspect, the long pillar without the wall is partially located on the basement floor.

According to the second aspect of the present invention, a part of the pillar having no wall is located on the basement floor, so that it is possible to construct a seismic isolation structure having a space in the form of a pillar on the ground.

According to a third aspect of the present invention, there is provided a structure in which a low-rise portion is formed around a high-rise portion, wherein no wall is provided between pillars at a height corresponding to at least a third floor portion from a foundation of the high-rise portion, The floor constituting the first floor from the foundation is mounted on the beam in a state where the floor is cut off from the beam and the column, and a damping device is installed between the lower surface of the floor and the column.

According to the third aspect of the present invention, the long columns extending from the foundation to at least the height corresponding to the third floor portion increase the natural period of the building and enhance the seismic isolation effect of the high-rise part.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a seismic isolation structure will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of a seismic isolation structure according to a first embodiment, and FIGS. 2 and 3 are a sectional view and a plan view in which a seismic isolation device is provided between a lower surface of a floor and a column.

FIG. 1 is a cross-sectional view of a base-isolated structure having a basement. Under the base-isolated structure 1, a basement floor 5 is formed by a basement outer wall 3 inside a mountain retaining wall 2 and a foundation slab 4. Built,
On the base slab 4, a steel column 6 supporting a structure is erected. These pillars 6 are not provided with walls from the foundation slab 4 to the height corresponding to the third-floor portion (for two layers).
Only the beam 8 supporting the floor 7 of the floor is erected and becomes a long pillar,
The seismic isolation effect is exhibited by this deformation performance. The column 6 is not limited to a steel frame, and may be a reinforced concrete column.

The floor 7 on the first floor is rigidly connected to the outer basement wall 3, but is placed on the upper surface thereof in a state of being cut off from the beam 8,
The horizontal load is transmitted only by the frictional force.
Further, a displacement absorbing space 9 is provided between the floor 7 and the pillar 6, and is closed by a cover 10.

As shown in FIGS. 2 and 3, a damping device 11 such as an oil damper or an air damper is provided between the column 6 and the lower surface of the floor 7 in the displacement absorbing space 9. The rear end portions 12a of these dampers are attached to the four corners of the column 6 and the front end portion of the cylinder 12b is attached to the lower surface of the floor 7 to provide a radial arrangement centered on the column 6, so that it can cope with a swing from any direction. It has become. Therefore, the horizontal load caused by the earthquake acting on the building is attenuated by the deformation performance of the long column and the damping device,
The floor 7 is transmitted only by the frictional force with the beam 8.

FIG. 4 shows a seismic isolation structure 13 according to the second embodiment.
It is composed of a high-rise part 14 and a three-story low-rise part 15 built around it. The high-rise portion 14 and the low-rise portion 15 are cut off, and (1) shows a beam 1 of the low-rise portion 15.
Reference numeral 6 denotes a type mounted on the bracket 20 a of the column 20 of the high-rise section 14. Also, (2) in FIG.
This is a type in which the beams 16 and 18 of the lower layer portion 15 are cantilevered.

In such a marginal state, the floor 1 of each floor
9 is rigidly connected to the beam 16 and the column 17 in the low-rise portion 15, but the displacement absorption space 21 is provided between the beam 16 and the column 20 in the high-rise portion 14, and is in a state of being cut off from the beam 18. A damping device 23 such as an oil damper or an air damper as shown in FIGS. 2 and 3 is provided between the floor 19 and the pillar 20 in the high-rise section 14. Reference numeral 22 denotes a cover that covers the displacement absorbing space 21.

Similarly, between the columns 20 in the high-rise section 14, no wall is provided up to the height corresponding to the third-floor portion (two layers), and only the beams 18 for supporting the floor 19 on the second floor are installed. As a result, it becomes a long pillar, and its seismic isolation effect can be demonstrated by its deformability.

Therefore, when an earthquake occurs, the high-rise
Since the natural periods of the lower part 4 and the lower part 15 are different from each other, they each oscillate independently. However, the horizontal load of the high part 14 is attenuated by the deformation performance of the long column and the damping device 23, and the horizontal load of the low part 14 is also damped. 23.

[0019]

[Effect of the Invention] At least 3 floors (2 layers) from the foundation
Since the natural period of the building can be lengthened by long columns up to the height equivalent to, the seismic isolation effect is efficiently exhibited.

Since a part of the long pillar without a wall is located on the basement floor, it is possible to construct a seismic isolation structure having a space of a piloti type on the ground.

[Brief description of the drawings]

FIG. 1A is a sectional view of a seismic isolation structure according to a first embodiment, and FIG. 1B is a sectional view taken along line AA of FIG.

FIG. 2 is a sectional view of a floor on which a seismic isolation device is installed.

FIG. 3 is a plan view of a floor on which the seismic isolation device is installed.

FIG. 4A is a cross-sectional view of a seismic isolation structure according to a second embodiment, and FIG. 4B is a cross-sectional view of a main part.

FIG. 5 is a sectional view taken along line BB of FIG. 4;

FIGS. 6A and 6B are cross-sectional views of a conventional seismic isolation structure.

[Explanation of symbols]

 1, 13, 24, 25 Seismic isolation structure 2 Retaining wall 3 Underground outer wall 4 Foundation slab 5 Basement floor 6, 17, 20 Column 7, 19 Floor 8, 16, 18 Beam 9, 21 Displacement absorption space 10, 22 Cover 11, 23, 31 Attenuator 14, 29 High-rise 15, 30 Low-rise 27 Upper structure

Claims (3)

[Claims] 1. A wall is not provided between pillars from a foundation to a height corresponding to at least a third floor portion, and a floor constituting the first floor from the foundation is mounted on the beam in a state where the floor is cut off from the beam and the column. A seismic isolation structure, wherein a damping device is installed between a lower surface of the floor and a column. 2. The seismic isolation structure according to claim 1, wherein a part of the pillar having no wall is located on a basement floor. 3. A structure in which a low-rise portion is formed around a high-rise portion, wherein no wall is provided between pillars at a height corresponding to at least a third floor portion from the foundation of the high-rise portion, and a first floor is formed from the foundation. A seismic isolation structure characterized in that the floor to be constituted is placed on the beam in a state where the floor is cut off from the beam and the column, and a damping device is installed between the lower surface of the floor and the column.