JPS6140830B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a seismic isolation device for a building that absorbs horizontal vibrations of the ground during an earthquake and reduces transmission to the superstructure.

Ordinary seismic waves often have predominant short-period components, so if the natural period of a building is lengthened, the building will be less likely to be excited by an earthquake, making the building safer against earthquakes. can.

One way to lengthen the natural period of a multi-story building is to make the floor height of a certain floor of the building higher than other floors, especially by increasing the floor height of the first floor. There is.

This is to lengthen the natural period of the building by making the pillars on the first floor longer than the floor height of the upper floor to make the first floor of the building more easily deformable.

However, if the first floor is made of long columns and a large horizontal displacement δ is allowed on this floor during an earthquake, the load P of the upper floors applied to the long columns will act vertically, so the long columns will experience a bending moment due to the horizontal force of the earthquake. In addition, a bending moment that is the product of the horizontal displacement δ and the load P is added (P-δ effect), which may make the entire building unstable.

When designing a building, it is essential that even floors that allow large horizontal displacements are kept within elastic deformation, so a considerable safety factor must be taken into consideration for long columns.

In order to eliminate such problems, the present invention has the following features:
In a building whose superstructure consists of columns and walls, a ball bearing is inserted between the lower end of the column and the substructure, and adjacent columns are connected with a steel horizontal member, and a steel plate is connected between the horizontal member and the substructure. The present invention provides a seismic isolation structure for buildings, which is characterized by being connected by vertical members made of

Embodiments of the present invention will be explained with reference to the drawings: 1
2 is a lower structure such as a foundation or an underground building, and 2 is an upper structure composed of columns 3, beams 4, and walls. Reference numeral 5 denotes a ball bearing sandwiched between the lower end surface of each column 3 and the lower structure 1, which is fixed to the pressure plate 6 fixed to the lower end surface of the column 3 and the upper surface of the lower structure 1, and A plurality of steel balls 5a are pressed between lower pressure plates 7 having a large planar shape, and a stopper 8 is integrally provided on the outer periphery of the upper pressure plate 6 to prevent the balls 5a from slipping out. The ball 5a is arranged vertically so that the ball 5a rolls on the lower pressure plate 7.

Reference numeral 9 denotes a flexible steel horizontal member whose both ends are connected to the opposing surfaces of adjacent pillars 3, 3 of the superstructure, and 10 is a flexible steel horizontal member whose upper end is rigidly connected to the lower surface of the middle of the horizontal member 9. 11 is a flexible steel vertical member whose lower end is connected to the upper surface of the lower structure 1.

The manner in which the horizontal member 9 is joined to the column 3 and the manner in which the vertical member 10 is joined to the lower structure 1 are determined by rigidly connecting them 12 and 1 by appropriate means, respectively, as shown in FIG.
3 and 14, or, as shown in FIG.
By inserting both ends of the horizontal member 9 and the lower end of the vertical member 10 between the opposing surfaces of the horizontal member 9 and the lower end of the vertical member 15, the ends of the horizontal member 9 and the vertical member The lower ends of the members 10 may be connected, or, as shown in FIG. They may be bonded, and furthermore, such bonding modes may be combined.

Further, a plurality of vertical members 10 may be connected between one horizontal member 9 and the lower structure 1 at appropriate intervals in the length direction of the horizontal member 9.

To describe the operation of the seismic isolation device configured as described above, if an earthquake occurs and the lower structure 1 vibrates in the horizontal direction, the lower end of the column 3 on the first floor of the upper structure 2 will move through the ball bearing 5. Since it is supported on the lower structure 1, almost no horizontal force is transmitted to the upper structure 2 by the ball bearing 5. Further, the horizontal member 9 joined between the adjacent pillars 3, 3 of the upper structure 2 and the lower structure 1 are connected by a vertical member 10, and these horizontal members 9 and vertical members 10 are made of flexible steel. Therefore, as shown in Figure 5, the deformation characteristics due to the horizontal stress P absorb the energy of horizontal vibration through elastic and plastic deformation, and the horizontal force transmitted to the superstructure 2 and columns 3 is only the stress O within a certain limit. be. FIG. 4 shows the deformed state when horizontal vibration is applied.

In this way, the structure is such that only the load of the superstructure 2 acts on the column 3 and the load is not applied to the vertical member 10, and the horizontal force due to earthquake motion is isolated from being transmitted to the superstructure 2 by the ball bearing 5. At the same time, the horizontal vibration energy is absorbed through the vertical member 10 and the horizontal member 9, and when the vibration stops, the upper structure 2 is restored to its original position due to the restoring characteristics of the vertical member 10 and the horizontal member 9. It is something.

In addition, as shown in FIG. 2, the lower structure 1 has a column holder 16 erected on its upper surface facing each column 3 of the upper structure 2 and having a larger cross-sectional shape than the column 3. The base 16 may support the lower end surface of the column 3 via the ball bearing 5.

As described above, the present invention provides a structure in which the upper structure consists of columns and walls, and by interposing a ball bearing or the like between the lower end of the column and the lower structure, the horizontal direction of the upper and lower structures can be adjusted. A horizontal member made of flexible steel is connected between adjacent columns of the superstructure to enable relative displacement, and the upper end of a vertical member made of flexible steel is connected to the middle part of the horizontal member. This relates to a seismic isolation device for a building that is rigidly connected and the lower end of this vertical member is connected to the lower structure, so the upper structure is supported with respect to the lower structure via ball bearings. Therefore, the upper and lower structures are insulated against horizontal forces, and in the event of an earthquake, almost no horizontal vibrations are transmitted to the upper structure, so there is no need to make the upper structure earthquake-resistant. This is not only economical, but also eliminates the fear of earthquakes among residents.

In addition, since the axial force of the pillars of the upper structure is directly transmitted to the lower structure, and the axial force does not act on horizontal or vertical members, horizontal displacement occurs like the long columns of the conventional flexible first story story. A large additional moment (P-δ effect) does not occur when The expected design has become possible, and in the event of an earthquake, these horizontal and vertical members will absorb the energy of horizontal vibrations,
Once the earthquake subsides, the superstructure can be immediately restored to its original position.

Further, according to the present invention, by appropriately selecting the length, cross-sectional area, material, number, etc. of the horizontal and vertical members, it is possible to create a flexible structure according to the properties of the ground and the building. Since the horizontal members and vertical members are installed in the spaces between the columns of the superstructure, they can be replaced as necessary, making maintenance management of them easy. The seismic isolation device of the present invention can be adopted without any restrictions.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIGS. 1 and 2 are simplified front views of the devices of Examples 1 and 2, FIG. 3 is a sectional view of the ball bearing, and FIG. 4 shows the horizontal displacement state. The simplified front view shown in FIG. 5 is a Q-δ diagram. 1... lower structure, 2... upper structure, 3... pillar,
5...Ball bearing, 9...Horizontal member, 10
...Vertical member.

Claims (1)

[Claims] 1. In a building whose upper structure consists of columns, beams, and walls, by interposing a ball bearing, etc. between the lower end of the column and the lower structure such as a foundation or underground structure, the horizontal direction of these upper and lower structures can be improved. A flexible steel horizontal member is connected between adjacent columns of the superstructure, and the upper end of a flexible steel vertical member is located in the middle of the horizontal member. A seismic isolation device for a building, characterized in that the vertical member is rigidly connected to the base structure, and the lower end of the vertical member is connected to the lower structure.