JP2001090778A - Base isolation device and installing structure thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base isolation device easily installed even on a column having a small cross section and capable of bearing vertical support force even when meeting with a fire. SOLUTION: Laminated rubber 11 for always bearing a vertical load by replacing and arranging a vertical directional part of a column 1 and causing prescribed horizontal displacement at earthquake time and an annular disk 13 in a hollowed-out hole 12 formed by vertically penetrating through a part of a cross section of the laminated rubber 11 are formed as a steel plate laminated part 5 by leaving prescribed clearance 16 from a height of the laminated rubber 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation device and a mounting structure thereof, which can be easily mounted on a pillar having a small cross section, and can bear a vertical support force even in case of fire or the like. And its mounting structure.

[0002]

2. Description of the Related Art Generally, in a seismic isolation device having a laminated rubber as a main structure, a vertical column load is always applied to a laminated rubber portion. Therefore, if the seismic isolation layer on which the seismic isolation device is installed is damaged by a fire or the like, the flammable rubber portion may be burned and lose its support function. For this reason, seismic isolation layers such as underground spaces where seismic isolation devices are installed from the viewpoint of fire prevention, etc., have not been used as building facilities except for maintenance. However, in recent years, from the viewpoint of effective use of buildings, the capitals of pillars placed in underground spaces such as underground parking lots and machine rooms,
Designs may be made to install seismic isolation devices on the capitals of the floor or middle floor. In such a case, it is required to provide a structure for protecting the laminated rubber by providing a fireproof coating or the like around the seismic isolation device.

However, even if a seismic isolation device having a fireproof coating is exposed to a high temperature for a long time due to a fire or the like, the strength of the laminated rubber is reduced, and there is a possibility that the assumed vertical load of the column cannot be supported. Further, it is necessary to provide a fail-safe structure so that the function of the seismic isolation device can be maintained even after the earthquake, which exceeds the assumed deformation performance of the seismic isolation device. In a conventional building equipped with this seismic isolation device, a reinforced concrete sleeve wall or the like is often provided as a fail-safe structure on the side surface of a column in which the seismic isolation device is incorporated. The sleeve wall is provided at a predetermined distance from the seismic isolation device so that it does not interfere with the laminated rubber part against the shear deformation of the seismic isolation device during an earthquake, and temporarily bears the vertical load of the column in the event of a disaster. Has become.

FIG. 9 is a partial sectional view showing an example of a conventional seismic isolation device 50 having a fail-safe function. The seismic isolation device 50 uses a known laminated rubber 51 containing a lead plug. The seismic isolation device 50 has a structure in which a fine cylindrical lead plug 52 is embedded in a through hole formed in the center of a low attenuation laminated rubber 55 laminated in a cylindrical shape. In this type of seismic isolation device, a flange plate 53 having a larger diameter is integrally attached to the upper and lower surfaces of the laminated rubber 51,
The flange 60 is fixed between the foundation concrete 60 and the concrete column lower surface 61 by anchor bolts or the like (not shown) via the flange plate 53.

[0005] While the laminated rubber 55 containing lead plugs always bears a vertical load, the laminated rubber 51 first undergoes horizontal shear deformation during an earthquake, and the lead plug 52 is plastically deformed following this deformation. . Further, a fail-safe bearing 56 is provided in case the laminated rubber 52 loses its proof stress due to a fire or the like. The fail-safe bearing 56 is a column member having a small cross section integrally attached to the side surfaces of the upper and lower columns 57 and 58, and always has a predetermined gap 59 vertically.
Only in a separated state.

[0006]

Since the fail-safe bearing 56 is largely eccentric from the column core provided with the seismic isolation device 50, a large eccentric bending moment is applied to the original column when a vertical axial force acts after the disaster. Therefore, there is a problem that the reinforcing structure becomes large-scale because the acting axial force is large particularly in the case of a lower floor column. FIG.
As shown in (1), the fail-safe bearing 56 projects outward from the cross section of the pillar, which poses a problem in appearance, indoor space, and construction.

On the other hand, in the conventional method of mounting the laminated rubber on the pillar, the mounting is performed by a flange plate. However, a high-strength concrete pillar or a filled steel pipe concrete pillar (hereinafter referred to as a CFT pillar) which has been developed in recent years has been developed. .)
As for the columns that can bear a high axial force as in the above, the column cross section has been reduced in size. In this case, in the conventional seismic isolation device having a flange plate and its mounting structure, the dimensions of the column cross section are limited, and there is a possibility that the seismic isolation device of a desired standard cannot be mounted.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, to provide a compact fail-safe function for bearing a vertical axial force in place of a laminated rubber in the event of a disaster, and to provide a small-section column with an easy function. It is an object of the present invention to provide a seismic isolation device and a mounting structure for the device.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to a laminated rubber which is installed by replacing a part of a column in the vertical direction and always bears a vertical load and generates a predetermined horizontal displacement during an earthquake. And a steel plate laminated portion in which a steel plate is laminated in a hollow hole formed by vertically penetrating a part of the cross section of the laminated rubber while leaving a predetermined clearance from the height of the laminated rubber.

At this time, it is preferable that a lead plug is buried by vertically penetrating the steel sheet laminated portion.

As the mounting structure, the periphery of the flange plate mounted on the upper and lower ends of the laminated rubber of the seismic isolation device,
It has a holding flange consisting of a locking flange that locks over the entire circumference along the circumferential direction of the pillar, and a body winding part that is continuous from the locking flange to the end of the pillar, and the holding metal is fixed by fixing means. The seismic isolation device is fixed to an outer peripheral surface of the column and attached to a predetermined position of the column.

[0012] Further, a locking flange for locking the peripheral edge of a flange plate attached to the upper and lower ends of the laminated rubber of the seismic isolation device over the entire circumference along the circumferential direction of the column, and an end of the column from the locking flange. A wedge-shaped fixing jig composed of a body winding part continuous with the part and divided into several parts in the circumferential direction of the column,
A ring-shaped steel pipe for constraining the fixing jig in the radial direction from the outer periphery, and fixing the ring-shaped steel pipe to the outer peripheral surface of the column by fixing means so that the seismic isolation device is attached to a predetermined position of the column. It is characterized by the following.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a seismic isolation device according to an embodiment of the present invention. FIG. 1 is a partial cross-sectional view showing a partial cross-section so that the state of attachment of the seismic isolation device of the present invention to a pillar can be seen. FIG. 1 shows an example in which a seismic isolation device 10 is mounted on a concrete-filled steel pipe column 1 in which a column outer periphery 1a and an end face 1b are covered with a steel pipe. The laminated rubber 11 of the seismic isolation device 10 has a hollow cylindrical shape in which a hollow portion 12 having a diameter of about 1/3 is provided at the center. Furthermore, the hollow part 12
, An annular disk 13 having a circular hole formed in the center portion is laminated to a predetermined height to form a steel plate laminated portion 5. Further, a cylindrical lead plug 14 is inserted into a circular hole at the center of the annular disk 13.
Is inserted. A flange plate 15 is integrally attached to the upper and lower surfaces of the laminated rubber 11.

In these constructions, the laminated rubber 11 is a seismic isolation member in which thin steel plates and rubber sheets are alternately laminated as in the prior art. The annular disk 13 is made of fire-resistant steel (FR steel) having a thickness of about 12 to 25 mm. Refractory steel is a known special steel sheet to which an alloying element for improving the heat resistance of a material is added. Even if the steel is exposed to a high temperature due to a fire or the like, there is almost no decrease in mechanical properties. The thickness can be set to an appropriate thickness depending on the size of the seismic isolation member and the like.

Further, the laminated rubber 11 above the steel plate laminated portion 5
A clearance 16 is provided between the upper surface and the upper surface. The clearance 16 is set to a height equal to or higher than the vertical compression deformation and creep deformation of the laminated rubber 11 expected when a load is constantly applied, so that the vertical axial force does not act on the annular disk 13 even if the laminated rubber 11 is deformed. Has become.

The plurality of stacked circular disks 13 are
It can slide on each other and follow the horizontal deformation caused by the earthquake. If the rubber sheet of the laminated rubber 11 burns or the lead plug 14 melts in a fire, the annular disc 13
Has a function as a fail-safe bearing that bears the vertical load of the column. In this fail-safe bearing, the vertical load on the column acts on the column core in the same manner as always, which is advantageous in terms of column design.

Here, the structure for mounting the above-described seismic isolation device 10 on a pillar will be described. As shown in FIGS. 1 and 2, the seismic isolation device 10 fixes and holds the periphery of the flange plate 15 attached to the upper and lower sides of the laminated rubber 11 with the holding metal fitting 20 whose entire circumference is divided into two pieces. Thus, it is fixed to the column end face 1b. The holding member 20 has a substantially L-shaped cross section including a locking flange 21 capable of locking the peripheral edge of the flange plate 15 and a body winding portion 22 which is continuous with the locking flange at a right angle and contacts the side surface of the column.
It is bent to have a curvature equal to the diameter of the illustrated CFT column 1. In the present embodiment, the holding metal members 20 equally divided in the circumferential direction are each fixed to the outer peripheral surface of the CFT column 1 by six post-installed anchor bolts 23. That is, with the locking flange 21 of the holding metal 20 covering the periphery of the flange plate 15 of the laminated rubber 11, the body winding portion 22 of the holding metal 20 is fixed to the anchor bolt 23.
Seismic isolation device 10
Can be firmly attached to the column 1.

FIG. 3 is a schematic sectional view showing a horizontal shear displacement state of the seismic isolation device 10 shown in FIG. 1 during an earthquake. As shown in the figure, when a predetermined shearing deformation occurs in the laminated rubber 11, the inner annular disk 13 follows the displacement of the laminated rubber 11 and shifts at each contact surface, and as a whole side view. Displace to form a parallelogram.

FIG. 4 is a cross-sectional view schematically showing a state immediately after the rubber sheet of the laminated rubber 11 has disappeared or melted due to a fire, and it became impossible to bear the vertical load.
When the laminated rubber 11 that always bears the vertical load of the column 1 disappears, the tip 14a of the lead plug 14 is crushed, the clearance 16 is lost, and the load from the column 1 is supported by the laminated annular disk 13. You.

The structure and mounting structure of the seismic isolation device 10 which does not use a lead plug as a modification of the present invention will be described with reference to FIGS. The illustrated seismic isolation device 10 is composed of a laminated rubber 11 having a hollow portion 12 equivalent to that shown in FIG. 1, in which a laminated disk 18 is accommodated, and a steel plate laminated portion 5 is formed. . A clearance 16 similar to that described above is provided above the steel plate laminated portion 5. In the case of the seismic isolation device 10 made of the low-damping laminated rubber 11, a damper (not shown) is provided.

The mounting structure of the seismic isolation device 10 will be described. When attaching the seismic isolation device 10,
Of the flange plate 15 of the laminated rubber 11 is surrounded by a ring-shaped steel pipe 25 having a predetermined taper formed on the inner peripheral surface thereof.
A locking flange 26 having a predetermined curvature in the circumferential direction between the FT column 1 and the locking flange 26 capable of locking with the flange plate 15, and a body winding portion 27 connected to the locking flange 26 and in contact with the side surface of the pillar. And a wedge-shaped fixing jig 28 having a substantially L-shaped cross section is provided. By inserting this fixing jig 28 into the gap, the flange plate 1
5 is firmly fixed to the end face of the CFT column 1. In addition, the ring-shaped steel pipe 25 is fixed to the side surface of the column 1 by a predetermined number of anchor bolts 23. In the present embodiment, the fixing jig 28 has a dimension and a shape obtained by dividing the entire circumference of the flange plate 15 into six.

FIGS. 7 and 8 are front views showing a part of a mounting structure for mounting the seismic isolation device 10 of the present invention to the end of the reinforced concrete column 2. FIG. 7 corresponds to the mounting structure of FIG. 1, and FIG. 8 includes the mounting structure corresponding to FIG. In general, in the case of a reinforced concrete column 5 cast in place, the external dimensions can be adjusted relatively easily. However, when the size of the column section is different from the flange plate 15 of the seismic isolation device, the column section is smaller than the flange plate 15. By filling the large gap with grout 7,
It is preferable that the fixing flanges 21 and 26 of the fixing jig 28 can securely fix the flange plate 15.

[0023]

As described above, according to the present invention,
It can be easily attached to and detached from a pillar with a small pillar cross section, so that the vertical bearing capacity of the laminated rubber, which was always in charge of the building when a building encounters a fire, can be substituted.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an embodiment of a seismic isolation device according to the present invention.

FIG. 2 is a plan sectional view taken along the line II-II of the seismic isolation device shown in FIG.

FIG. 3 is a state explanatory diagram showing a displacement state of the seismic isolation device shown in FIG. 1 during an earthquake.

FIG. 4 is a state explanatory view showing a state after the fire of the seismic isolation device shown in FIG. 1;

FIG. 5 is a partial sectional view showing one embodiment of the seismic isolation device according to the present invention.

FIG. 6 is a plan sectional view of the seismic isolation device shown in FIG. 5, taken along the line VI-VI.

FIG. 7 is a partial cross-sectional view showing a state where the seismic isolation device shown in FIG. 1 is attached to a reinforced concrete column.

8 is a partial cross-sectional view showing a state where the seismic isolation device shown in FIG. 5 is attached to a reinforced concrete column.

FIG. 9 is a partial cross-sectional view showing an example of a conventional seismic isolation device and its mounting structure.

FIG. 10 is a plan sectional view of the seismic isolation device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CFT column 2 Reinforced concrete column 5 Steel plate lamination part 10 Seismic isolation device 11 Laminated rubber 12 Hollow hollow part 13 Annular disk 14 Lead plug 15 Flange plate 16 Clearance 18 Disk 20 Pressing fitting 21, 26 Locking flange 22, 27 Body winding 23 Anchor bolt 25 Ring-shaped steel pipe 28 Fixing jig

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2E001 DE01 DG02 EA01 FA02 FA29 FA41 GA01 GA07 GA24 GA65 HB02 HB06 HE01 KA03 LA01 LA06 LA11 3J048 AA02 AC01 BA08 BB03 BE12 CB07 DA01 EA38 3J066 AA01 AA26 BA01 BA05 BB01 BB06

Claims (4)

[Claims] 1. A laminated rubber which is installed so as to replace a part of the column in the vertical direction and always bears a vertical load, and which causes a predetermined horizontal displacement during an earthquake, and a part of a cross section of the laminated rubber is vertically penetrated. And a steel plate laminated portion in which a steel plate is laminated in the formed hollow with a predetermined clearance from the height of the laminated rubber. 2. The seismic isolation device according to claim 1, wherein a lead plug is buried vertically penetrating the steel plate laminated portion. 3. A locking flange for locking the peripheral edge of a flange plate attached to the upper and lower ends of the laminated rubber of the seismic isolation device over the entire circumference along the circumferential direction of the pillar, and the pillar from the locking flange. A holding member consisting of a continuous winding part at an end of the base member, and the holding member is fixed to an outer peripheral surface of the column by fixing means, and the seismic isolation device is attached to a predetermined position of the column. Mounting structure for seismic isolation device. 4. A locking flange for locking the peripheral edge of a flange plate attached to the upper and lower ends of the laminated rubber of the seismic isolation device over the entire circumference along the circumferential direction of the column, and an end of the column from the locking flange. A wedge-shaped fixing jig composed of a body winding part continuous with the part and divided into several parts in the circumferential direction of the column, and a ring-shaped steel pipe for constraining the fixing jig in the radial direction from the outer periphery; A mounting structure for a seismic isolation device, wherein the steel pipe is fixed to an outer peripheral surface of the column by fixing means, and the seismic isolation device is mounted at a predetermined position of the column.