JPH0932002A - Base isolation structure for wooden houses - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a base isolation structure that can reliably prevent damage or collapse of a wooden house due to rolling during an earthquake. [Structure] A foundation 22 constructed on the ground is provided with a concave spherical surface 24 having a concentric spherical curvature centered on the center of gravity of a wooden house 23 installed on the foundation 22, and the bottom of the wooden house 23 has the above-mentioned curved surface. A spherical curved surface 26 having a curvature smaller than that of the concave surface 24,
When the foundation 22 rolls due to an earthquake, the wooden house 23 swings around its center of gravity, which prevents damage and collapse.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base isolation structure for preventing damage to a wooden house against vibration such as an earthquake.

[0002]

2. Description of the Related Art Generally, a wooden house has a structure in which a foundation is formed in the ground by using concrete or steel frame, and the house is constructed on the foundation and fixed with bolts or the like.

It is as experienced in the Great East Japan Earthquake that the vibration of a wooden house having the above-mentioned structure is directly transmitted to the house due to vibration such as an earthquake and causes damage such as collapse and damage.

In order to prevent these problems, various vibration-proof and vibration-isolation structures for buildings have been proposed in the past and have been put to practical use.

FIG. 5 shows a conventional vibration isolation structure as disclosed in Japanese Patent Laid-Open No.
1-196022 proposed, the base 3 is placed on the base 1 via the horizontally movable base spacer 2 so that the base 3 can move laterally, and the upper end of the anchor bolt 4 embedded in the base 1 and the base. The lower end of the anchor bolt 5 for fastening the base penetrating 3 is fixed to the anchor plate 6 and the rubber seat plate 7 for cushion.
The rubber seat plate 7 absorbs the rolling motion of the foundation 1 at the time of an earthquake and prevents it from being transmitted to the base 3.

FIGS. 6 (A) and 6 (B) show a conventional vibration isolation structure using ball bearings, in which the dish-shaped plate 8 is provided on the vertically opposing surfaces of the foundation 1 fixed to the ground and the base 3 of the building. 9 is provided, and a ball bearing 12 is interposed between the dish-shaped recesses 10 and 11 formed on the upper and lower facing surfaces of the dish-shaped disks 8 and 9.

FIG. 6 (A) shows a normal state in which no vibration is applied, and due to the centripetal nature of the dish-shaped recesses 10 and 11, the base 3 is located directly above the foundation 1.

FIG. 6 (B) shows a state at the time of rolling caused by an earthquake, and the rolling of the ball bearing 12 interposed between the dish-shaped recesses 10 and 11 prevents the rolling of the foundation 1 from being transmitted to the base 3. It will be.

[0009]

By the way, in the conventional vibration-isolating structure, as shown in FIGS. 5 and 6, it is necessary to provide additional devices such as dampers and ball bearings between the foundation and the base. In addition, they must be maintained and managed so that they can always operate, and moreover, labor and time are required when installing a house, resulting in a problem that the construction cost of a wooden house becomes very expensive. is there.

Therefore, an object of the present invention is to eliminate the need for providing an auxiliary device between the foundation and the building, to perform vibration isolation, to easily maintain and manage the house, to easily install the house, and to reduce the construction cost. The purpose is to provide a base isolation structure for houses.

[0011]

In order to solve the above-mentioned problems, the invention of claim 1 provides the ground foundation with a spherically curved concave surface having a curvature of a concentric sphere centered on the center of gravity of the house,
The bottom of the house has a curvature smaller than the curvature of the spherical concave surface, and the structure in which this house is installed on the foundation is adopted.

According to the second aspect of the present invention, a substance having an anti-friction effect is adhered to the surface of the base having a concave spherical surface and the bottom surface of the house.

According to the third aspect of the present invention, a structure is provided in which a supplying means for supplying an anti-friction material having an anti-friction effect from the outside is provided to the surface of the base having a spherical concave surface and the sliding surface of the bottom surface of the house. Is.

According to a fourth aspect of the present invention, a vibration measuring device is interlocked with the supply means so that the anti-friction material is supplied from the outside under a predetermined vibration or more.

Here, in the house installed on the foundation, the bottom of the house rests on the spherical concave surface of the foundation, and when the foundation rolls when an earthquake occurs, the rolling of the foundation is transmitted to the lower part of the house. A house has the property that its center of gravity stops at a fixed position,
Moreover, since the spherical concave surface provided on the foundation has a curvature of a concentric sphere with the center of gravity of the house as the center point, the house swings around the center of gravity to release the rolling motion, thereby Prevent damage and collapse.

Further, by attaching or supplying a substance having an antifriction effect to the spherical concave surface of the foundation and the surface of the bottom of the house,
It is possible to reduce the occurrence of friction between the foundation and the bottom of the house at the time of rolling of the foundation, smooth the swing of the house, and reliably prevent the seismic force causing the rolling from directly transmitting to the house.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. 1 to 4 of the accompanying drawings.

In the first embodiment shown in FIG. 1, the ground 2
1. A wooden house 23 is installed on the foundation 22 provided in 1, and a spherical curved concave surface 24 having a concentric sphere curvature centered on the center of gravity of the house 23 is provided on the upper surface side of the foundation 22, and a bottom portion 25 of the house 23 is provided.
The lower surface has a spherical curved surface 26 smaller than the curvature of the spherical curved concave surface 24.

In the first embodiment, the spherical curved concave surface 24 of the foundation 22 is formed into one spherical curved surface corresponding to the planar size of the house 23, and the spherical curved surface 26 of the house 23 is also formed as a whole. It has a spherical curved surface.

The curvature of the bottom spherical curved surface 26 of the house 23 is set small as described above with respect to the curvature of the spherically curved concave surface 24 provided on the foundation 22, but the spherically curved concave surface 24 of the foundation 22 as a whole is set. In the case of one spherical curved surface, the bottom spherical curved surface 26 approaches the curvature of the spherical curved concave surface 24 within the range of the above setting conditions,
The house 23 is stably supported on the foundation 22.

In the second embodiment shown in FIG. 2, the spherically curved concave surface 24 of the foundation 22 is formed into a single spherical curved surface as a whole as in the first embodiment, and the lower portion of the house 23 has a large number of pillars. And each pillar 27 is formed on the foundation 22 by the house 2
The length is set according to the curvature of the spherically curved concave surface 24 so that 3 is in a horizontal state, and the lower end of each column 27 has a curvature smaller than the curvature of the spherically curved concave surface 24.

In the third embodiment shown in FIG. 3, the multiple pillars 27 provided at the bottom of the house 23 have the same length, and the foundation 2
The portion of the upper surface of 2 which supports the lower end of each column 27 is formed as an independent spherical concave surface 24.

In each of the above embodiments, the bottom portion 25 and the pillars 27 of the foundation 22 and the house 23 are formed by using, for example, concrete. However, the bottom portion 25 and the pillar body 27 of the foundation 22 are swayed when an earthquake occurs. Reduces frictional resistance,
For smooth sliding, as shown in FIG. 4, the spherical curved concave surface 2
A substance having an effect of reducing the friction coefficient, for example, metal plates 28 and 29 is attached to either one or both of 4 or the bottom portion 25 and the spherical curved surface 26 of the column 27.

The anti-friction material such as the metal plates 28 and 29 may have a reduced anti-friction effect due to oxidation due to long-term aging. To prevent this, as shown in FIG. The mechanism 30 is installed, and the spherical curved concave surface 24 and the spherical curved surface 26
Lubricating oil or the like is supplied to the sliding surface as the anti-friction material to maintain or restore the anti-friction effect.

Although not shown in the drawings, the refueling mechanism 30 is not shown.
Vibration measuring equipment such as a seismograph may be interlocked to forcibly supply the lubricating oil when an earthquake of a predetermined seismic intensity or higher occurs.

The vibration-isolated foundation structure of the present invention is constructed as described above, and the house 23 installed on the foundation 22 is illustrated by the centripetal action of the spherically curved concave surface 24 provided on the foundation 22 when the ground is stationary. It is in a horizontal state like.

Next, when the foundation 22 horizontally vibrates due to an earthquake, the house 23 vibrates due to the frictional force between the spherical concave surface 24 and the spherical curved surface 26.

At this time, the force acting on the house 23 is the spherical concave surface 2
4 is proportional to the friction coefficient between the spherical curved surface 26 and the spherical curved surface 26, the friction coefficient can be reduced by forming the friction surface with the metal plates 28 and 29 and applying or supplying lubricating oil to the sliding surface. Thereby, the vibration of the house 23 can be attenuated as compared with the foundation 22.

In the vibration of the house 23, the vibration is applied from the portion on the foundation 22 so that the house 23
Tries to stop its center of gravity at a certain position. At the same time, since the spherically curved concave surface 24 of the foundation 22 has a concentric sphere curvature centered on the center of gravity of the house 23, the spherically curved concave surface 24 allows swinging about the center of gravity of the house 23.

Therefore, the entire house 23 swings around its center of gravity against the vibration of the foundation 22 caused by an earthquake, so that the house 23 is not damaged or collapsed.

When the foundation 22 is stationary after the earthquake, the concave spherical surface 24 of the foundation 22 has a concentric sphere curvature centered on the center of gravity of the house 23, so that the bottom portion 25 and the pillar 27 of the house 23 are It returns to the lowest point of the spherically curved concave surface 24, and therefore the house 23 automatically returns to the horizontal posture.

The mitigation corresponding to the vertical vibration of the earthquake is
It can be performed by means of interposing an appropriate rubber-like elastic substance or an elastic body (spring or the like) made of corrosion-resistant metal other than rubber, for example, stainless steel, under the vertical pillar on the house side.

[0033]

As described above, according to the present invention, the foundation provided on the ground is provided with the concave spherical surface having the curvature of the concentric sphere with the center of gravity of the house as the center point, and the house is installed on the foundation. Since the bottom has a curvature smaller than the curvature of the spherical concave surface, the house swings around its center of gravity against the lateral roll of the foundation due to the earthquake, causing damage and collapse due to the horizontal roll of the wooden house. Can be reliably prevented.

If a substance having an antifriction effect is attached to the sliding surface between the spherical concave surface of the foundation and the spherical curved surface of the house bottom, or if an antifriction material is supplied to this sliding surface, It is possible to reduce the coefficient of friction between the bottom of the house and the bottom of the house, reduce the amount of rocking of the house against the rolling of the foundation, and more reliably isolate the house.

When the antifriction material is supplied to the sliding surface from the outside, it is possible to supply unnecessary antifriction material by interlocking a vibration measuring device and supplying the antifriction material only when a predetermined vibration occurs. It can be omitted.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional view showing the second embodiment.

FIG. 3 is a longitudinal sectional view showing the third embodiment.

FIG. 4 is a vertical sectional view showing a lubricating oil supply mechanism.

FIG. 5 is a vertical sectional view showing a conventional vibration isolation structure.

FIG. 6A is a vertical cross-sectional view showing another example of the conventional vibration isolation structure, and FIG. 6B is an enlarged cross-sectional view of an essential part showing the same operation as above.

[Explanation of symbols]

 22 Foundation 23 Wooden House 24 Spherical Concave Surface 25 Bottom 26 Spherical Curved Surface 27 Column 28, 29 Metal Plate 30 Oiling Mechanism

Claims (4)

[Claims] 1. The ground foundation is provided with a spherical concave surface having a curvature of a concentric sphere with the center of gravity of the house as a center point, and the bottom of the house has a curvature smaller than the curvature of the spherical surface.
A base isolation structure for a wooden house where this house will be installed on the foundation. 2. A base isolation structure for a wooden house according to claim 1, wherein a substance having an anti-friction effect is adhered to the surface of the spherical concave surface of the foundation and the bottom surface of the house. 3. A wooden house according to claim 1 or 2, further comprising a supply means for supplying an anti-friction material having an anti-friction effect to the sliding surfaces of the spherical concave surface of the foundation and the bottom surface of the house from the outside. Base isolation structure. 4. A base isolation structure for a wooden house according to claim 3, wherein the antifriction material is externally supplied in a state of a predetermined vibration or more by interlocking a vibration measuring device with the supply means.