JP2760822B2 - Base-isolated floor structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a device for damping and absorbing vertical and horizontal vibrations of an access floor of a building on which electronic devices and the like are mounted in the event of an earthquake or the like. The present invention relates to a seismic isolation floor structure with a free access floor, which significantly reduces the effects of vibrations on electronic equipment.

[Conventional technology]

In general, an advanced communication system is configured by integrating fine and delicate components such as a super LSI, so that it is particularly susceptible to vibration and impact. Therefore, when installing devices such as an advanced communication system and an electronic computer on the floor of a building, various seismic isolation floors have been proposed in order to ensure the safety of the devices against vibration shock due to an earthquake or the like. Such a conventional seismic isolation floor structure is disclosed in, for example, JP-A-62-86265. This is one in which four corners of a steel frame of the floor structure are supported by bearing balls so as to be horizontally movable, and a spring damper fixed horizontally on a base slab and the floor structure are connected by a rope-shaped member. Also, the one disclosed in Japanese Utility Model Laid-Open No. 62-204055 is rotatably held at a lower portion of a movable member connected to an upper movable side in a conical recess of a fixed side member connected to a fixed side. A large steel ball is brought into contact therewith to cope with a large relative displacement in the horizontal direction between the fixed side and the movable side.

[Problems to be solved by the invention]

However, in the above-mentioned conventional base-isolated floor structure, in the case of vibration due to an earthquake or the like, the former absorbs horizontal vibration by a damper acting in the horizontal direction, and the latter absorbs horizontal vibration between the fixed side and the movable side. The displacement is replaced by the rotation of the steel ball in the conical concave portion, all of which are mainly aimed at absorbing and absorbing horizontal vibration. Therefore, there is a problem that an influence on electronic devices and the like cannot be prevented for a large earthquake accompanied by vertical vibration.

The present invention has been made in view of such problems of the related art, and has as its object to solve the above problems by providing a seismic isolation unit for vertical vibration.

[Means for solving the problem]

According to the seismic isolation floor structure of the present invention, a seismic isolation unit having a function of damping and absorbing vertical vibrations composed of an elastic body and a fluid damper is interposed between the upper frame and the lower frame, and is provided between the lower frame and the concrete floor. In this method, a horizontal spring made of an elastic body having a function of absorbing horizontal vibration and a bearing ball supporting the lower frame are interposed, a free access floor is formed in the upper frame, and a part of the lower frame is raised. A cushioning material for absorbing horizontal vibration is interposed between the upper part of the lower frame and the access floor installed on the concrete floor, and a plurality of bearing balls are interposed between the upper frame side and the lower frame side. Become. Preferably, the access floor is at the same height as the free access floor.

[Action]

When the elastic body and the fluid damper are integrally vibrated, the vibration is damped and absorbed. Since the seismic isolation unit, which is composed of such an elastic body and a fluid damper, is interposed between the upper frame and the lower frame, this seismic isolation unit is not affected by the impact from the lower frame due to the vertical vibration of the earthquake. The vibration is buffered and attenuated and transmitted to the upper frame. The horizontal vibration is damped and absorbed by a horizontal spring made of an elastic body interposed between the lower frame and the concrete floor.
Due to the rotation or slippage of the bearing balls supporting the lower frame, the input to the upper and lower frames reaches a plateau.

Therefore, the vertical vibration and the horizontal vibration of the earthquake are transmitted to the object on the free access floor formed in the upper frame in a greatly attenuated state.

In addition, since the bearing balls are interposed between the upper frame side and the lower frame side, even if the free access floor is subjected to uneven left and right vertical vibration, the floor does not tilt to one side and stays horizontal. Vibrates up and down.

Further, since a part of the lower frame is raised and a cushioning material for absorbing horizontal vibration is interposed between the upper part of the lower frame and the access floor installed on the concrete floor, the horizontal vibration via the access floor is provided. Is also absorbed by the cushion material and transmitted to the free access floor.

When the access floor is at the same height as the free access floor, the entire floor including the access floor and the free access floor can be used as one floor.

〔Example〕

Hereinafter, the present invention will be described with reference to the drawings. First to sixth
FIG. 1 is a diagram showing one embodiment according to the present invention.

FIG. 1 is a partial cross-sectional view showing a base-isolated floor structure to which a base-isolation unit according to the present invention is attached, and FIG. 2 is a plan view of the base-isolated floor. , 1/4 of the whole).

In the drawing, 1 is a free access floor, 2 is an upper frame that forms four sides of a shape steel, 3 is a plurality of joists provided in parallel between opposed beams of the upper frame, and is a member that receives the free access floor 1. is there. 2a is a through hole for passing a cable or the like.

Reference numeral 4 denotes a lower frame formed so as to surround the outer periphery of the upper frame 2. A plurality of ribs 5 made of flat steel are provided, and a small joist 6 is attached to the upper end of the rib. Further, on this small joist, an upper sliding plate 7 is attached to four rounds of an upper end portion of the lower frame 4, and an upper surface thereof can be slidably contacted with a lower surface of another access floor 8. Numeral 9 denotes a cushion material made of a pipe type rubber, which is interposed between the upper end of the lower frame 4 and a side end of the other access floor 8, and absorbs and absorbs the vibration of the lower frame 4 when the horizontal vibration occurs. It is an auxiliary member for performing.

Reference numeral 10 denotes a seismic isolation unit, which is an elastic body 11 such as a coil spring.
And a damper 12, which has a function of absorbing and damping vibrations applied in the axial direction and of rapidly damping vibrations. As shown in FIG. It is interposed between the frame 4. When the free access floor 1 is square, the number of the seismic isolation units 10 to be installed is at least at four corners of the square in this embodiment.

Reference numeral 13 denotes a bearing ball rotatably attached to at least four corners of the lower frame 4, and reference numeral 14 denotes a lower sliding plate provided on a concrete surface 15 corresponding to the bearing ball 13.

Numeral 16 denotes a bearing ball interposed between both side surfaces of the lower frame 4 and the upper frame 2. The bearing ball 16 is rotatably mounted on the side surface of the upper frame 2 so that even if the free access floor 1 is subjected to uneven vibration. The floor 1 oscillates up and down while maintaining a horizontal position, thereby preventing the floor 1 from inclining with respect to the lower frame 4 to be in a rocking state.

FIG. 3 is a plan view of the upper frame 4, and FIG. 4 is a view taken in the direction of arrow B in FIG. Reference numeral 17 denotes a horizontal spring beam which forms a part of the lower frame 4, and has a horizontal spring 18 made of cylindrical rubber interposed between the beam and a concrete floor surface 15 at the center thereof. This horizontal spring 18 has both end surfaces fixed to the lower surface of the horizontal spring beam 17 and the concrete upper surface 15, respectively.
The horizontal vibration of the concrete surface is buffered and absorbed in the horizontal direction with respect to the lower frame 4 integrated with the horizontal spring beam 17, and
It has the function of returning the free access floor 1 to its original position when the earthquake stops.

 The seismic control action will be described with the above configuration.

In FIG. 5, the vertical vibration P ₀ of the earthquake that occurred on the concrete floor 15 is transmitted to the lower frame 4 through the bearing balls 13 with almost the same size, and the vertical vibration transmitted to the lower frame 4 is transmitted to the seismic isolation unit. It is transmitted to the upper frame 2 via 10. At this time, the seismic isolation unit 10 attenuates and absorbs the impact vibration caused by the vertical vibration as described above, and is transmitted as a vertical vibration P ₁ that hardly hinders the equipment mounted on the free access floor 1. Will be. Also, at this time, even if, for example, uneven vibration is applied to the upper frame 2, the lower frame 4
Since the upper frame 2 moves up and down while keeping the horizontal level due to the provision of the bearing balls 16 which are in rolling contact with the side surfaces, the upper frame 2 does not incline with respect to the lower frame 4 and is not locked.

Next, in FIG. 6, the horizontal vibration Q ₀ generated on the concrete floor 15 is absorbed and absorbed by the horizontal spring 18, and the bearing ball 13 supporting the lower frame 4 rotates or slides on the slide plate 14. the input to the lower frame 2, 4 is a plateau, to mitigate damage to the horizontal vibration to Q ₁ level that does not cause to the device on the raised floor 1. In addition, the cushioning material 9 provided between the free access floor 1 and the other access floor 8 reduces horizontal vibration from the other floor 8 and the other floor 8 provides the sliding plate 7 provided on the lower frame 4. Horizontal vibration from other floors 8 is also mitigated by the relative displacement caused by sliding.

Figures 7, 8, and 9 show examples of other seismic isolation units.
Denotes a leaf spring as an elastic body, and 22 denotes an air damper as a fluid damper. This is because the leaf spring 21 is replaced with an air damper instead of the coil spring 11 in the above embodiment.
22 and the upper and lower frames 2,
It is interposed between four. FIG. 7 is a plan view showing the arrangement of each component in this case, and FIG. 9 is a sectional view taken along the line CC of FIG.

In any of the seismic isolation units described above, the weight of the upper frame plus the weight of the electronic equipment mounted on the free access floor and the magnitude of the vibration of the concrete floor frame due to the expected earthquake are given. What is necessary is just to design and determine the function of each part, the number of arrangements, and the arrangement position.

〔The invention's effect〕

As described above, according to the present invention, it is possible to provide a free access floor that can significantly suppress and mitigate horizontal and vertical swings, and that a plurality of floors are provided between the upper frame side surface and the lower frame side surface. Even if the free access floor is subjected to uneven vertical vibration in the horizontal direction due to the interposition of the bearing balls, the floor does not tilt to one side and the floor surface can be maintained in a horizontal state There is. In addition, cushion material is interposed between the free access floor and the adjacent access floor,
Horizontal vibrations that pass through the access floor are also absorbed by the cushioning material and are suppressed from being transmitted to the free access floor. Not designed as a floor.

Further, when the access floor is at the same height as the free access floor, there is an effect that the entire floor including the access floor and the free access floor can be used as one floor.

[Brief description of the drawings]

1 (a) is a sectional view of a floor portion to which a seismic isolation unit according to the present invention is attached, FIG. 1 (b) is a partial view of FIG. 1 (a) as viewed from an arrow A, and FIG. FIG. 3 is a plan view of an access floor, FIG. 3 is a plan view of a lower frame in FIG. 2, FIG. 4 is a view taken in the direction of arrow B in FIG. 3, FIG. FIG. 7 is an explanatory view of the seismic isolation operation of horizontal vibration, FIG. 7 is a component arrangement diagram in another embodiment, FIG. 8 is a front view of the seismic isolation unit in another embodiment, and FIG. FIG. 1 ... raised floor, 2 ... upper frame, 4 ...
Lower frame, 10: seismic isolation unit, 11: elastic body, 12
…… Fluid damper, 13 …… Lower bearing ball, 14 ……
Sliding board, 15 ... Concrete floor, 16 ... Upper bearing ball, 18 ... Horizontal spring.

Claims (2)

(57) [Claims] A seismic isolation unit having a function of damping and absorbing vertical vibration, comprising an elastic body and a fluid damper, is interposed between an upper frame and a lower frame, and a horizontal unit is provided between the lower frame and the concrete floor. A horizontal spring made of an elastic material having the function of absorbing vibration and a bearing ball supporting the lower frame are interposed, a free access floor is formed in the upper frame, and a part of the lower frame is raised and the upper part of the lower frame is raised. And between the access floor installed on the concrete floor, interposed cushioning material to absorb horizontal vibration,
A base-isolated floor structure in which a plurality of bearing balls are interposed between the upper frame side and the lower frame side. 2. The seismic isolation floor structure according to claim 1, wherein said access floor is at the same height as said free access floor.