JP2736435B2 - Base-isolated floor structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a seismic isolation floor structure suitable for attenuating transmission of vibrations such as earthquakes to important security facilities.

[Conventional technology]

Critical security facilities, such as computer centers, nuclear reactor facilities, or museums and museums, are required to be protected from failure or damage even in the event of an unexpected large earthquake, and therefore the floor of the building that houses them is seismically isolated. The use of floor structures has been practiced.

As this seismic isolation floor structure, it has been proposed to use a three-dimensional seismic isolation support device that simultaneously attenuates not only horizontal vibration but also vertical vibration by combining an air spring and laminated rubber. In the case, the seismic isolation support device in which the air spring and the laminated rubber are stacked vertically and combined is arranged at predetermined intervals vertically and horizontally, the floor frame is movably supported by the seismic isolation support device, and the floor panel is laid on the floor frame. A movable floor structure is used.

The laminated rubber has a structure in which a rubber-like elastic material and a reinforcing plate such as a steel plate or a hard plastic plate are alternately laminated and integrated. On the other hand, it has the characteristic that it is rigid and has a large spring constant, and it is soft and has a small spring constant against horizontal loads.The ratio of the vertical and horizontal spring constants is 100 to 1
000. In such a support device using only the laminated rubber, even if sufficient seismic isolation is obtained in the horizontal direction, the seismic isolation in the vertical direction may be insufficient.

Also, as the laminated rubber, a large single laminated rubber can be used for each seismic isolation support device, but it prevents buckling, secures a sufficient horizontal displacement, and has a high damping performance against low frequency vibration. As a seismic isolation support structure, a multi-layer laminated rubber assembly is used in which a plurality of laminated rubbers are vertically stacked at a plurality of positions and the upper and lower end surfaces of the laminated rubber of each stage are connected to each other by a stabilizer.

On the other hand, the air spring exerts a superior seismic isolation effect in the vertical direction.

The air spring comprises an inflatable and compressible air chamber filled with compressed air, and the air chamber is generally connected to an auxiliary air tank via a tube having a throttle for providing vibration damping. The auxiliary air tank is connected to an air pressure source such as a compressor via a tube having a leveling valve for adjusting a level or a spring constant.

In addition, the floor frame is mainly configured by using a shape steel such as an H-shaped steel, and the auxiliary air tank is generally configured by a cylindrical container, and is mainly attached to the floor frame.

A conventional example of the above-described three-dimensional seismic isolation support device is disclosed in, for example, Japanese Patent Application Laid-Open No. 63-89751.

[Technical problem to be solved by the invention]

However, in the above-mentioned conventional base-isolated floor structure, the auxiliary air tank is constituted by a single member, and thus has the following technical problems.

i) It is necessary to separately manufacture an auxiliary air tank, which increases the number of man-hours for constructing the base-isolated floor structure and increases the manufacturing cost.

ii) The auxiliary air tank must be fixed to a floor frame or the like on site, which requires a lot of man-hours and increases the construction period.

iii) Since the auxiliary air tank is mounted on site, there is a possibility that a problem such as loosening of the mounting portion occurs in a long period of time.

iv) The capacity of the auxiliary air tank cannot be easily increased. That is, the diameter of the tank cannot be increased so much because of the space under the floor. If the length of the tank is too long, it cannot be accommodated between pedestals (floor panel supporting means) provided at predetermined pitch intervals along the floor frame.

The present invention has been made in view of the above-mentioned conventional technical problems, and is capable of ensuring a sufficient capacity of the auxiliary air tank without being restricted by space.
It is an object of the present invention to provide a base-isolated floor structure capable of reducing the number of construction steps.

[Means for solving the problem]

The present invention provides a seismic isolation floor structure in which a floor panel is laid on a floor frame supported by a seismic isolation support device in which an air spring and a laminated rubber are vertically stacked and combined, and at least a part of the floor frame is medium air. The above object is achieved by forming the auxiliary air tank connected to the air spring with a floor frame having the medium airtight structure.

[Action]

A part of the floor frame, which was mainly formed in a section steel such as an H-section steel, has a pipe-shaped or box-shaped medium airtight structure,
Since this portion is connected to the air chamber of the air spring and used as an auxiliary air tank, the floor frame (beam) and the air tank can be shared.

〔Example〕

 Hereinafter, the present invention will be specifically described with reference to the drawings.

FIG. 6 is a partial plan view of a floor provided with a base-isolated floor structure according to the present invention, and FIG. 7 is a partial longitudinal sectional view taken along line VII-VII in FIG.

6 and 7, a seismic isolation floor structure 20 using a three-dimensional seismic isolation support device 23 according to the present invention is constructed in a building including a floor slab 21 and a surrounding wall slab 22.

The seismic isolation floor structure 20 includes a plurality of seismic isolation support devices 23 arranged on a floor slab 21 at predetermined vertical and horizontal pitches (for example, at intervals of 3000 mm), and supported vertically and horizontally on the seismic isolation support devices 23. Floor frames (beams) 24 and these floor frames 24
The pedestal 25 includes a height-adjustable pedestal (seat) 25 mounted thereon at predetermined vertical and horizontal pitches, and a floor panel 26 supported and laid on the pedestal 25.

A fixed floor structure 30 is provided around the seismic isolation floor structure 20 at predetermined intervals.

The fixed floor structure 30 is provided with a predetermined width along the inside of the wall slab 22, and includes a fixed base 31 fixed on the floor slab 21 and a fixed panel 32 supported on the fixed base 31. .

The fixed base 31 has an area for slidably supporting the periphery of a floor panel (movable panel) 26 on the seismic isolation floor structure 20.

Between the fixed panel 32 and the movable floor panel 26,
A buffer panel 27 is provided for absorbing a horizontal relative displacement between the panels 32 and 26 during an earthquake. The buffer panel 27 is slidably supported on the fixed base 31.

Further, a peripheral portion of the movable floor panel 26, that is, a portion 26A adjacent to the buffer panel 27 can move up and down to some extent, and has a structure capable of absorbing vertical displacement.

Note that the floor panel 26 is a base-isolated floor portion and occupies most of the floor area in the building, while the fixed panel 32 is a floor portion that vibrates integrally with the building, and its area is minimal. Is selected.

The buffer panel 27 provided along the entire peripheral edge of the movable floor panel 26 may be a panel having a structure that can easily reduce the width dimension when subjected to a horizontal force, for example, a rubber-like elastic material plate or slipping on each other. It can be composed of a plurality of blocks having a slope.

A finishing material such as a carpet or a tile is laid on the floor including the movable panel 26, the fixed panel 32, and the buffer panel 27.

FIG. 1 is a partial longitudinal sectional view showing the seismic isolation floor structure of the present invention including one of the seismic isolation support devices 23 in FIG.

1 and 7, the seismic isolation support device 23 has a structure in which a bellows-type air spring 35 and a multi-stage laminated rubber assembly 36 are vertically stacked and connected.

In FIG. 1, the air spring 35 is connected to upper and lower end plates 38A and 38B of a bellows 37 formed of an air bag (air chamber) filled with compressed air, and connects a lower end plate 38B to an upper end. It is structured to be vertically movable along four guide shafts 39 planted at four corners of the face plate 38A.

The guide shaft 39 is provided with a stopper 41 for regulating the maximum compression position of the air spring 35.

1 and 7, the inside of an air chamber (bellows in this embodiment) 37 of the air spring 35 is connected to an auxiliary air tank 43 formed in the floor frame 24 by an air supply path (tube). Connected through 42. A throttle 44 for providing the vibration damping capability of the air spring 35 is provided in the middle of the air supply path 42.

Further, the auxiliary air tank 43 is connected to an air pressure source 46 such as a compressor via a tube 45, and a leveling valve for adjusting the height (level) or the spring constant of the air spring 35 in the middle of the tube 45. 47 is connected.

Thus, each air spring 35 is configured such that the air chamber 37 is connected to the auxiliary air tank 43 so that the natural frequency in the vertical direction can be adjusted by changing the air pressure and the amount of air. The capacity of the auxiliary air tank 43 is selected to be, for example, about 10 l for one seismic isolation support device 23.

With the structure described above, the seismic isolation floor structure of the present invention, that is, the seismic isolation support device 23 in which the air spring 35 and the laminated rubber (multi-layer laminated rubber assembly in the illustrated embodiment) 36 are vertically stacked and connected. In the base-isolated floor structure 20 in which the floor panel 26 is laid on the floor frame 24, at least a part of the floor frame 24 has a medium airtight structure, and an auxiliary air tank 43 connected to the air spring 35 is provided in the middle. A seismic isolation floor structure 20 is provided, which is constituted by a floor frame 24 having an airtight structure.

FIG. 8 is a side view showing the details of the multi-layer laminated rubber assembly 36, and FIG. 9 is a sectional view taken along line IX-IX in FIG.

8 and 9, the multi-layer laminated rubber assembly 36
Means that a plurality of (four in the illustrated example) laminated rubber elements 51 as elastic elements are stacked up and down at a plurality of positions (four in the illustrated example), and the upper and lower end surfaces of the laminated rubber 51 at each stage are stabilized by the stabilizing plate 52. Has a structure connected to each other.

Each laminated rubber 51 has a structure in which a rubber-like elastic material and a reinforcing plate such as a steel plate or a hard plastic plate are alternately laminated and integrated, and the stabilizer 53 is integrally provided on upper and lower end faces by a flange 53. It is fastened and fixed.

The multi-layer laminated rubber assembly 36 thus configured is fixed to the floor slab 21 at its lower end, and has the air spring 35 at its upper end.
Are combined.

FIG. 10 shows a state in which the multi-layer laminated rubber assembly 36 of FIG. 8 has been displaced in the horizontal direction by seismic force.

As shown in FIGS. 8 and 9, according to the multi-layer laminated rubber assembly 36 in which the laminated rubber 51 as the element elastic body is connected by the stabilizer 52, the upper and lower end faces of the laminated rubber 51 are stable. Since it is restrained by the plate 52, the structure becomes stable as a whole.

Therefore, even when seismic force is applied, a large horizontal displacement can be obtained without buckling as shown in Fig. 10, and the supporting load per unit area can be reduced as compared with the case of supporting with a single laminated rubber. It can be greatly increased.

By using the multi-layer laminated rubber assembly 36 described above with reference to FIGS. 8 to 10, a large displacement (for example, ± 200 mm) is obtained in the horizontal direction, and a high-damping rubber is used as the rubber layer of each laminated rubber 51. If used, the seismic isolation support device 23 having high vibration damping ability and exhibiting excellent seismic isolation performance without using a damper can be obtained.

In the seismic isolation floor structure of FIG. 7, the floor frame 24 is lowered as much as possible to secure a space between the movable floor panel 26 and wiring to a computer or the like installed on the floor panel. It has a structure that can be easily performed.

When the seismic isolation support device 23 shown in FIG. 1 is used,
It is preferable that the load per unit is usually set to about 1 to 10 tons.

FIG. 2 is a perspective view schematically showing an auxiliary air tank 43 formed by the floor frame 24 having a medium airtight structure.

In FIG. 2, the floor frame 24 is made of a square pipe having a square cross section and a medium airtight structure, and the inside thereof is used as the auxiliary air tank 43.

The floor frame 24 is provided with U
Pedestal 25 using bolts 61 and fixing plate 62
Has been fixed.

Each pedestal 25 has a screw engaging portion with a lock nut 63, and is adjustable in height.

On each pedestal 25, the floor panel 26 is laid.

The auxiliary air tank 43 is connected to an air chamber 37 of the air spring 35 via an air supply path (tube) 42. In the middle of the air supply path 42, the air spring 35 has a vibration damping capability. Aperture 44 is provided.

The auxiliary air tank 43 is provided with a leveling valve 47.
Is connected to an air pressure source 46 such as a compressor.

The leveling valve 47 is for adjusting the height of the air spring 35 by adjusting the amount of air or the air pressure in the auxiliary air tank 43.

FIG. 11 is a longitudinal sectional view illustrating the structure and operation of the leveling valve 47.

11 (A) is a neutral position, (B) is an operation when the floor load is increased and the floor panel 26 is lowered, and (C) is an operation when the floor load is reduced and the floor panel 26 is raised. Are respectively shown.

In FIG. 11, the relative displacement between the movable floor panel 26 and the floor frame 24 is changed to the vertical movement of the tip of the lever 71, and the lever 71 rotates around the fulcrum by an angle corresponding to the displacement. .

By the rotation of the lever 71, the plunger 72 is moved up and down in the cylinder, and the suction and discharge valve 73 operates.

First, as shown in FIG. 11 (A), when the lever 71 is at the neutral position, the suction / discharge valve 73 is seated, and the supply / discharge of compressed air to / from the air spring 35 is not performed.

As shown in FIG. 11 (B), when the load on the floor panel 26 increases and the level of the floor panel 26 decreases, the supply / discharge valve 73 leaves the valve seat and the orifice 75 with the check valve 74.
, The floor panel 26 is gradually pushed upward, the lever 71 is returned to the neutral state, and the supply is stopped.

As shown in FIG. 11 (C), when the load on the floor panel 26 decreases and the floor panel 26 floats, the plunger 72 rises, and an exhaust hole 76 on its lower surface is opened apart from the supply / discharge valve 72, Since the output air of the air spring 35 is released to the atmosphere, the floor panel 26 gradually descends.

 When the lever 71 returns to the neutral position, the exhaust stops.

FIG. 3 is a side view illustrating the specific structure of the floor frame 24 having a medium airtight structure forming the auxiliary air tank 43, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. The floor frame 24 is formed of a thin-walled pipe (usually made of steel) having a square cross section and a predetermined length.
Auxiliary air tank 43 with medium airtight structure by welding
Are formed.

In addition, mounting holes 65 for connecting the air supply passage 42 and the tube 45 are formed on the side surface of the floor frame 24.

As the thin-walled pipe forming the floor frame 24, for example, a steel pipe having a length and width of 125 mm and a thickness of 4.5 mm or a thickness of about 150 mm × 80 mm and a thickness of about 4.5 mm is used, and by using such a steel pipe, the floor load is reduced. Rigidity and tank capacity can be secured.

FIG. 5 is a plan view illustrating a part of the layout of the floor frame 24 and the air spring 35 in the seismic isolation floor structure of the present invention.

In the illustrated layout, most of the floor frame 24 has a medium airtight structure such as a square pipe, and is made available as the auxiliary air tank 43. By adjusting the capacity of the auxiliary air tank 43, the spring constant of the air spring 35 is adjusted. Is adjusted.

When the capacity of the auxiliary air tank 43 for each air spring 35 is increased, the spring constant is softened and the seismic isolation effect can be increased.

In the layout of FIG. 5, three auxiliary air tanks 43 are formed using three floor frames A, B and C among the floor frames 24 arranged vertically and horizontally, and each air spring
35, 35 are connected in series to the three auxiliary air tanks A, B, C by piping 68, 68 as shown.

On / off valves 69 are provided in the pipes 68, 68 between the auxiliary air tanks A, B, C, and by operating these on / off valves 69, the number of auxiliary air tanks 43 to be used is adjusted. be able to.

In addition, after three floor frames 24 have a medium air-tight structure in advance and only one floor frame 24 is used as the auxiliary air tank 43, two or three floor frames 24 are connected to the auxiliary air tank 43. The specification can be changed by additional construction to use as.

At the time of use, a load such as a computer is applied to each floor frame 24, and each auxiliary air tank 43 constituted by a part (possibly all) of the floor frame 24 has an air spring 35 It is connected and bears the load transmitted from the floor frame.

When a dynamic load is applied to the air spring 35 due to an earthquake or the like, air flowing into the air spring 35 reciprocates between the auxiliary air tank 43 and the diaphragm 44 produces vibration damping ability.

In this case, when the capacity of the auxiliary air tank 43 with respect to the compressed air chamber 37 of the air spring is increased, the spring stiffness is reduced, a soft air spring is obtained, and the seismic isolation effect can be enhanced.

According to the embodiment described above, the following effects were obtained.

i) Since the floor frame 24 has an airtight structure and the inside is used as the auxiliary air tank 43, there is no need to separately prepare the auxiliary air tank, so that the number of construction steps can be reduced and the cost can be reduced.

ii) The man-hour for fixing the auxiliary air tank to the floor frame 24 or the like on site can be eliminated, and the construction period can be shortened.

iii) Since it is also used as the floor frame 24, the auxiliary air tank 43
Capacity could easily be increased, and the seismic isolation effect could be easily increased.

iv) Since the floor frame 24 has a thin hollow structure, the weight of the entire frame can be reduced.

In the above embodiment, the laminated rubber 36 is constituted by a multi-stage laminated rubber assembly as shown in FIG. 8, but it can be constituted by a large single laminated rubber without using a stabilizer or the like.

In the illustrated configuration, the air spring 35 is connected to the laminated rubber 36. However, the same applies when the air spring is placed upside down and the air spring is placed below.

Further, the air spring 35 is not limited to the bellows type shown in the figure, and other types of air springs such as a diaphragm type may be used.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, in the base-isolated floor structure in which the floor panel is laid on the floor frame supported by the base-isolated support device in which the air spring and the laminated rubber are stacked up and down and combined, Since at least a part of the floor frame has a medium air-tight structure, and the auxiliary air tank connected to the air spring is configured by the floor frame having the medium air-tight structure, it is not necessary to separately create an auxiliary air tank, and the structure is reduced. Therefore, a seismic isolation floor structure that can easily increase the capacity of the auxiliary air tank and improve the seismic isolation effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of one embodiment of a base isolation floor structure according to the present invention, FIG. 2 is a schematic perspective view showing a main part configuration of an auxiliary air tank in FIG. 1, and FIG. 2 is a partial side view of the floor frame constituting the auxiliary air tank in FIG. 2, FIG. 4 is a sectional view taken along line IV-IV in FIG. 3, and FIG. FIG. 6 is a schematic partial plan view illustrating a layout, FIG. 6 is a partial plan view showing an example of a base-isolated floor structure embodying the present invention, and FIG. 7 is a partial longitudinal section along line VII-VII in FIG. FIG. 8 is a side view illustrating a multi-layer laminated rubber assembly used in the seismic isolation support device in FIG. 7, FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. FIG. 10 is a side view schematically showing a state in which the multi-stage laminated rubber assembly of FIG. 8 is displaced in the horizontal direction, and FIG. 11 is a longitudinal sectional view showing the structure and operation of the leveling valve. 20 ... seismic isolation floor structure, 23 ... seismic isolation support device, 24 ... floor frame, 26 ... floor panel (movable panel), 35 ... air spring, 36 ... laminated rubber (multi-stage laminated rubber assembly) , 37 …… Compressed air chamber, 42 …… Air supply path, 43 …… Auxiliary air tank,
44 …… Aperture, 45 …… Tube, 46 …… Air pressure source, 47 ……
Leveling valve.

Claims (1)

(57) [Claims] In a seismic isolation floor structure, a floor panel is laid on a floor frame supported by a seismic isolation support device in which an air spring and a laminated rubber are vertically stacked and combined, and at least a part of the floor frame is placed inside. A seismic isolation floor structure having an airtight structure, wherein an auxiliary air tank connected to the air spring is formed by the floor frame having the medium airtight structure.