JP5267197B2 - Double floor structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain fail-safe and maintenance-free operation in a damping means used for damping vibrations in the vertical direction of a double floor structure. <P>SOLUTION: The double floor structure includes: a horizontal structural plane 2 horizontally arranged at regular intervals above a floor slab; a vertical structural plane 7 installed on the upper part of the floor slab and supporting the horizontal structural plane 2; and the damping means 10 interposed between the horizontal structural plane 2 and the vertical structural plane 7 of and damping the vibrations in the vertical direction of the horizontal structural plane 2. The mounting surface 15d of a mounting part 15 of the damping means 10 is fitted slidably in the horizontal direction to the mounting surface 9d of a mounting part 9c of at least either the structural plane of the horizontal structural plane 2 and the vertical structural plane 7. The double floor structure includes a holding member 50 abutting on the mounting part 9c of the structural plane 7 and the mounting part 15 for the damping means 10 with the surfaces 15f and 9f on the reverse sides of the mounting surfaces 15d and 9d respectively for holding the mounting parts 15 and 9 together. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a double floor structure used in a semiconductor factory or the like.

  In precision production factories such as semiconductor factories, severe conditions are imposed on daily fine vibrations. In such a factory, steel structures that are often adopted from the viewpoints of cost, construction period, etc., are caused by vibrations generated by the semiconductor production equipment itself or by walking of workers engaged in manufacturing. May interfere with manufacturing. In particular, since vertical vibration often becomes a problem, various techniques have been proposed to reduce this vertical vibration.

  For example, Patent Document 1 proposes a double floor structure 1 (see, for example, FIG. 2). That is, a vertical construction surface 7 is constructed on the floor slab 25 of the building frame by the pillars 8 and braces 9, and the small beams 5 are horizontally laid on the vertical construction surface 7 via the large beams 4, and these large beams 4 And the horizontal panel 2 is constructed by installing the floor panel 6 on the beam 5. A viscoelastic damper is interposed as a damping means 10 between the brace 9 forming the vertical surface 7 and the large beam 4 forming the horizontal surface 2. Vibration can be effectively reduced.

JP 2007-270604 A

Here, the viscoelastic damper 10 is intended for micro-micrometer-order micro vibrations. For this reason, when attaching the viscoelastic damper 10 to the vertical construction surface 7 and the horizontal construction surface 2, a high degree of adhesion to the attachment surfaces is required, and is fastened and fixed by, for example, fastening bolts. Further, since the same micro-vibration is targeted, the limit deformation amount of the viscoelastic damper 10 is about several centimeters at most, and is damaged when a horizontal displacement larger than this is input.
On the other hand, for example, in the case of a large earthquake, a ground motion having an amplitude exceeding several centimeters in the horizontal direction is assumed. In this case, the viscoelastic damper 10 may be damaged.

  Therefore, application of a horizontal fail-safe structure to the viscoelastic damper 10 has been studied. As this fail-safe structure, the viscoelastic damper 10 is attached to be slidable in the horizontal direction with respect to at least one of the horizontal structural surface 7 and the vertical structural surface 2. It is conceivable to prevent the horizontal force that is sometimes generated from being input to the viscoelastic damper 10, and in that case, as a method of securing the adhesion between the mounting surfaces in place of the fastening bolts, the construction surface 7 (2) It is conceivable to sandwich the attachment portion of the above and the attachment portion of the viscoelastic damper 10 with a clamp or the like.

  However, when the viscoelastic damper 10 slides in the horizontal direction with respect to the structural surface 7 (2), the clamp comes off from the attachment portion of the viscoelastic damper 10 along with the sliding, or the clamp competes during movement. There is a risk of deformation. And when it falls off or deform | transforms, the restoration | recovery operation | work of a clamp is needed, and a manufacturing facility cannot be operated immediately after an earthquake, and it will interfere with manufacture of a semiconductor etc.

  The present invention has been made in view of the above-described conventional problems, and in a double floor structure capable of efficiently attenuating vertical vibration by a damping means such as a viscoelastic damper, the damping means is damaged by an earthquake. It is to achieve a fail-safe to prevent the occurrence of the failure and maintenance-free to free from any recovery work related to the attenuation means after the earthquake.

In order to achieve this object, the invention shown in claim 1
It is a double floor structure installed at the top of the floor slab of the building frame,
A horizontal construction surface disposed horizontally above the floor slab with a predetermined interval;
A vertical surface that is installed on top of the floor slab and supports the horizontal surface;
Attenuating means interposed between the horizontal surface and the vertical surface to attenuate the vibration in the vertical direction of the horizontal surface;
The attachment surface of the attachment portion of the attenuation means is attached to be slidable in the horizontal direction with respect to the attachment surface of the attachment portion of at least one of the horizontal composition surface and the vertical composition surface,
A gripping member that abuts the mounting portion of the construction surface and the mounting portion of the attenuation means on the opposite side of the mounting surface and sandwiches the mounting portions,
The friction coefficient related to the horizontal friction force between the sandwiching member and the mounting portion of the construction surface and the friction coefficient related to the horizontal friction force between the sandwiching member and the mounting portion of the damping means are It is characterized by being different.

  According to the first aspect of the present invention, when a horizontal force acts on the double floor structure at the time of an earthquake, the damping means slides on at least one of the structural surfaces, and thereby the damping means. The input of horizontal force is greatly reduced. As a result, damage to the damping means is effectively prevented.

  Further, during this sliding, the sandwiching member is attached to the surface having the larger friction coefficient of the surface and the damping means based on the above-described difference in the friction coefficient, and is quickly applied to the smaller friction coefficient. To slide. That is, the sandwiching member quickly slides according to the sliding between the construction surface and the damping means while maintaining the sandwiched posture. Therefore, it is possible to effectively prevent the sandwiching member from dropping from the mounting portion or the sandwiching member from being deformed, and it is possible to eliminate the work of re-installing the sandwiching member after the earthquake.

  From the above, fail-safe prevention that prevents damage to the attenuation means due to an earthquake and maintenance-free freedom from any recovery work related to the attenuation means after the earthquake are achieved.

The invention shown in claim 2 is the double floor structure according to claim 1,
The mounting portion of the construction surface is wider in the horizontal direction than the mounting portion of the attenuation means,
The friction coefficient related to the frictional force in the horizontal direction between the sandwiching member and the mounting portion of the damping means is larger than the friction coefficient related to the frictional force in the horizontal direction between the sandwiching member and the mounting portion of the construction surface. It is desirable that it is larger.

  According to the second aspect of the present invention, when the damping member slides in the horizontal direction with respect to the surface, the sandwiching member is a damping means having a large friction coefficient based on the friction coefficient difference. It follows the surface and slides quickly against the surface with a small coefficient of friction. Therefore, it is possible to effectively prevent the sandwiching member from falling off from the attachment portion of the attenuation means.

  Further, since the attachment portion of the construction surface is wider in the horizontal direction than the attachment portion of the attenuation means, even if the sandwiching member slides relative to the attachment portion of the construction surface, the attachment portion of the construction surface Dropout is unlikely to occur.

  As described above, it is possible to reliably prevent the sandwiching member from falling off from the attachment portion of the attenuation member and the attachment portion of the construction surface.

Invention of Claim 3 is the double floor structure of Claim 1 or 2,
The sandwiching member has a pair of sandwiching portions opposed to each other with a gap between them at both ends of the U-shaped or C-shaped member, and at least one of the pair of sandwiching portions serves as the other sandwiching portion. It is desirable that the clamp be provided so as to be able to advance and retract.

  According to the third aspect of the present invention, since the sandwiching member is a U-shaped or C-shaped clamp, even when the damping means is already fastened and fixed to the surface, the damping means is maintained. It can be easily changed to a damping means that is free and has a fail-safe function.

  For example, an existing bolt that fastens and fixes the attachment portion of the construction surface and the attachment portion of the damping means is removed, and instead, the clamp is attached to the attachment portion by using a distance between a pair of clamping portions of the clamp. If it inserts from a side, a clamp can be easily arrange | positioned in the position which can pinch | attach the said attaching part. That is, the clamping member as a clamp can be installed in the mounting portion without any problem, and as a result, the existing damping means can be changed without difficulty to a damping means that is maintenance-free and has a fail-safe function.

Invention of Claim 4 is the double floor structure of Claim 3, Comprising:
Between the one sandwiching portion provided in the sandwiching member and the attachment portion of the construction surface, and between the other sandwiching portion provided in the sandwiching member and the attachment portion of the damping means, It is desirable that a plate-like member having a size for closing the existing bolt hole is interposed.

  According to the fourth aspect of the present invention, even when the damping means is already fastened and fixed to the construction surface, the damping means can be easily changed to a damping means having a maintenance-free and fail-safe function. Become.

  For example, after removing the existing bolts that fasten and fix the damping means to the structural surface, the existing bolt holes remain in the mounting portion of the structural surface and the mounting portion of the damping means, and are sandwiched between the bolt holes. However, according to the above-described configuration, the existing bolt hole is blocked by the plate-like member. Therefore, the pinching portion can be prevented from falling into the bolt hole, and the pinching member can be installed in the mounting portion without any problem. As a result, the existing damping means is also maintenance-free and has a fail-safe function. It becomes possible to change to the attenuation means without difficulty.

Invention of Claim 5 is the double floor structure in any one of Claims 1 thru | or 4, Comprising:
It is desirable that the damping means is fastened and fixed in a non-slidable manner in the horizontal direction by fastening bolts on the construction surface which is not one of the horizontal construction surface and the vertical construction surface. .
According to the fifth aspect of the present invention, the damping means is fastened and fixed so as not to be slidable in the horizontal direction on either the horizontal surface or the vertical surface. The sandwiching member is not applied to the attachment portion of the surface, and therefore the sandwiching member cannot be dropped or deformed. Therefore, the probability of occurrence of the re-installation work of the sandwiching member can be reduced.

The invention shown in claim 6 is the double floor structure according to any one of claims 1 to 5,
The vertical construction surface includes an auxiliary member that does not bear a long-term load and a short-term load excluding its own weight in design,
It is desirable that the damping means is interposed between the auxiliary member and the horizontal surface.
According to the sixth aspect of the present invention, the vertical vibration generated on the horizontal surface can be effectively damped by the damping means.

  According to the present invention, it is possible to achieve fail-safe and maintenance-free damping means used in a double floor structure.

1 is a schematic plan view showing the entire double floor structure 1. FIG. It is a schematic perspective view which shows a part of FIG. 3A is a side view of the damping means 10, and FIG. 3B is a BB arrow view in FIG. 3A. It is the schematic diagram which looked at the double floor structure 1 from the side. FIG. 5A is a side view of the attachment structure of the viscoelastic damper 10 according to the first embodiment, and FIG. 5B is a cross-sectional view taken along line BB in FIG. 5A. FIG. 6A is a side view of a preferable mounting structure example, and FIG. 6B is a cross-sectional view taken along line BB in FIG. 6A. FIG. 7A is a side view of an existing viscoelastic damper 10 without a fail-safe function, and FIG. 7B is a cross-sectional view taken along line BB in FIG. 7A. FIG. 8A is a side view of the attachment structure of the viscoelastic damper 10 according to the second embodiment, and FIG. 8B is a cross-sectional view taken along line BB in FIG. 8A. It is a perspective view of the other example of the double floor structure 1. FIG. It is a perspective view of the other example of the double floor structure 1. FIG. It is a perspective view of the other example of the double floor structure 1. FIG.

=== First Embodiment ===
<<< About Double Floor Structure 1 >>>
1 and 2 are explanatory views of the double floor structure 1. FIG. FIG. 1 is a schematic plan view showing the entire double floor structure 1, and FIG. 2 is a schematic perspective view showing a part of FIG.

  The double floor structure 1 is applied to, for example, a clean room of a precision production factory. That is, the double floor structure 1 includes a floor slab 25 of a building frame such as a precision production factory as a lower floor and an upper floor 21 disposed on the floor slab 25. Various precision devices and production facilities are installed on the floor surface of the upper floor 21, while the space SP between the floor surface of the upper floor 21 and the floor slab 25 is connected to wiring, piping, air conditioning. Used for circulation, equipment delivery, etc.

  The upper floor 21 has a horizontal surface 2 that is horizontally installed above the floor slab 25 at a predetermined interval, and a vertical surface 7 that is vertically installed above the floor slab 25 and supports the horizontal surface 2. And a damping means 10 interposed between the horizontal surface 2 and the vertical surface 7.

  The horizontal construction surface 2 includes a large beam 4, a small beam 5, and a floor panel 6. The girder 4 is made of a steel material such as H-section steel, and is installed vertically and horizontally at a predetermined interval above the floor slab 25, thereby partitioning the upper part of the floor slab 25 in a lattice shape. The small beam 5 is made of a steel material such as an H-shaped steel having a smaller cross section than the large beam 4. And it spans horizontally between the big beams 4 and 4 which mutually oppose, and divides the said grid | lattice-like opening further finely. The floor panel 6 is a rectangular plate, for example, and is horizontally placed and fixed on the upper portions of the large beam 4 and the small beam 5. In addition, a joist (not shown) may be interposed between the large beam 4 and the small beam 5 and the floor panel 6 as necessary.

  The vertical construction surface 7 includes a column 8 such as H-shaped steel that supports the large beam 4 and an auxiliary member 9 such as H-shaped steel. Each column 8 is erected vertically on the portion of the floor slab 25 corresponding to the intersection of the large beams 4 and 4 that intersect each other. The auxiliary member 9 is, for example, a steel material in which a horizontal member 9b is interposed between a pair of diagonal members 9a and 9a arranged symmetrically in the horizontal direction. The horizontal member 9b of the auxiliary member 9 is connected to the middle portion of the large beam 4 via the damping means 10, and the end portions of the pair of diagonal members 9a and 9a are respectively connected to both ends of the large beam 4. It is connected to the lower end of each column 8 that supports the part. The auxiliary member 9 preferably does not bear a long-term load and a short-term load excluding its own weight in design, so that the damping means 10 is designed to efficiently attenuate the vertical vibration of the horizontal structural surface 2.

  In this example, each end portion of the diagonal member 9a of the auxiliary member 9 is rigidly connected to the lower end portion of the column 8 by welding or the like, but in some cases, the floor slab 25 adjacent to the lower end portion of the column 8 is used. This portion may be rigidly connected by an anchor bolt or the like.

  3A and 3B are explanatory diagrams of the attenuating means 10. FIG. 3A is a side view, and FIG. 3B is a BB arrow view in FIG. 3A.

  The damping means 10 is a viscoelastic damper. The viscoelastic damper 10 includes an upper member 11 connected to the large beam 4 side, a lower member 14 connected to the auxiliary member 9 side, and a viscoelastic body interposed between the upper member 11 and the lower member 14. 17, and the upper member 11 and the lower member 14 are configured to be relatively displaceable in the vertical direction and the longitudinal direction of the large beam 4 via the viscoelastic body 17.

  The upper member 11 is erected vertically on a horizontal attachment plate 12 (hereinafter also referred to as an upper attachment plate 12) as an attachment portion to the girder 4 and on the lower surface side of the upper attachment plate 12, and between each other. And a plurality of vertical plates 13, 13... (Three in the illustrated example) arranged with a predetermined gap therebetween. On the other hand, the lower member 14 is also erected vertically on a horizontal attachment plate 15 (hereinafter also referred to as a lower attachment plate 15) as an attachment portion to the auxiliary member 9 and the upper surface side of the lower attachment plate 15. And a plurality of vertical plates 16, 16... (Two in the illustrated example) inserted into the gaps between the vertical plates 13 of the upper member 11. In each gap S between the plate surface of the vertical plate 16 and the plate surface of the vertical plate 13 facing each other, a viscoelastic body 17 is provided integrally with these plate surfaces.

  Therefore, for example, an excitation force is input to the horizontal plane 2 by operating various production facilities installed on the horizontal plane 2 or walking of an operator on the horizontal plane 2. Even when the vibration in the vertical direction occurs, the vertical vibration is effectively damped by the damping characteristic of the viscoelastic body 17 related to the viscoelastic damper 10. That is, the vibration amplitude at the natural frequency of the horizontal surface 2 is not amplified, and amplification of the vibration amplitude in the vertical direction (decrease in dynamic rigidity) can be suppressed. As a result, it is possible to reduce the adverse effects that the precision equipment and the like on the horizontal surface 2 can be affected by their own vertical vibrations, and to fully exhibit their performance.

  The reason why the viscoelastic body 17 is layered and thinned in the double floor structure 1 described above is to improve the damping performance against micro vibrations. That is, by reducing the thickness of the viscoelastic body 17, a large shear strain (= the amount of deformation in the direction perpendicular to the thickness direction of the viscoelastic body / the thickness of the viscoelastic body) is generated even in a minute displacement. Thus, a large damping force is generated even under a slight vibration.

  However, when the thickness of the viscoelastic body 17 is reduced, the shear strain increases even with a small displacement as described above. In other words, when the thickness of the viscoelastic body 17 is reduced, the limit displacement corresponding to the limit shear strain of the viscoelastic body 17 is reduced. For example, when the limit shear strain of the viscoelastic body 17 is α × 100% and the design thickness of the viscoelastic body 17 capable of effectively suppressing micro vibrations is as thin as β mm, the limit of the viscoelastic body 17 The displacement is a small value of several centimeters (= α × β mm).

  On the other hand, the double floor structure 1 is required to have seismic soundness with respect to a large earthquake. Then, in the case of this large earthquake, a ground vibration having a horizontal amplitude exceeding several centimeters is assumed, and in this case, there is a possibility that the ground vibration having a horizontal amplitude is input to the viscoelastic damper 10 as it is.

  FIG. 4 is an explanatory diagram showing the double floor structure 1 in a side view. For example, in the event of an earthquake, as shown by the solid line in FIG. 4, the double floor structure 1 is deformed in the horizontal direction as a whole, that is, the large beam 4 of the horizontal construction surface 2 is greatly displaced in the horizontal direction. Does not deform much. Therefore, a difference in the amount of displacement in the horizontal direction is produced between the large beam 4 and the horizontal member 9 b of the auxiliary member 9, and the difference in the amount of displacement is input to the viscoelastic damper 10. That is, there is a possibility that the above-mentioned horizontal amplitude seismic motion exceeding several centimeters may be input to the viscoelastic damper 10 with almost the same size. In that case, the limit shear strain of the viscoelastic body 17 is exceeded. The viscoelastic damper 10 is damaged.

  Therefore, in the double floor structure 1 of the first embodiment, the following device is devised for the attachment structure of the viscoelastic damper 10 so that the viscoelastic damper 10 is not damaged even by a large earthquake. Has a fail-safe function. In addition to this, maintenance-free operation is also made so that no restoration work related to the viscoelastic damper 10 is required after the earthquake.

<<< Attachment structure of viscoelastic damper 10 >>>
5A and 5B are explanatory diagrams of the attachment structure of the viscoelastic damper 10 according to the first embodiment. 5A is a side view, and FIG. 5B is a cross-sectional view taken along line BB in FIG. 5A.

  The viscoelastic damper 10 is interposed between the large beam 4 and the horizontal member 9b of the auxiliary member 9 arranged to face each other directly below the large beam 4 while aligning the longitudinal directions thereof. In this example, the girder 4 is made of an H-shaped steel, and the pair of flanges 4a and 4a are arranged vertically. Further, the horizontal member 9b of the auxiliary member 9 is also made of H-shaped steel, and the pair of flanges 9c and 9c are arranged vertically. Therefore, the upper mounting plate 12 of the viscoelastic damper 10 is mounted with the horizontal lower surface 4d of the lower flange 4a of the large beam 4 as the mounting surface on the large beam 4 side, while the lower mounting plate 15 of the viscoelastic damper 10 is the auxiliary member. The horizontal upper surface 9d of the upper flange 9c of the horizontal member 9b (corresponding to “attachment portion of one construction surface”) is attached as an attachment surface on the auxiliary member 9 side.

  At this time, the horizontal mounting surface 12d of the upper mounting plate 12 of the viscoelastic damper 10 and the horizontal mounting surface 4d of the lower flange 4a of the large beam 4 need to be in close contact with each other. The horizontal mounting surface 15d of the lower mounting plate 15 of the elastic damper 10 and the horizontal mounting surface 9d of the upper flange 9c of the horizontal member 9b also need to be in close contact over substantially the entire surface. This is because the fine vibration in the vertical direction of the horizontal construction surface 2 is reliably transmitted to the auxiliary member 9 via the viscoelastic damper 10 and reliably attenuated by the viscoelastic damper 10. That is, this is to increase the dynamic rigidity of the horizontal surface 2 in the vertical direction.

  Here, for the former contact, that is, the contact between the mounting surface 4d of the lower flange 4a of the large beam 4 and the mounting surface 12d of the upper mounting plate 12 of the viscoelastic damper 10, for example, a fastening bolt 40 is used. Specifically, the fastening bolt 40 is provided by passing both the lower flange 4a of the girder 4 and the upper mounting plate 12 of the viscoelastic damper 10 in the vertical direction, and the fastening force of the nut 41 that is screwed into the fastening bolt 40 Thus, the lower flange 4a and the upper mounting plate 12 are fixed so as not to move relative to each other in the vertical direction and the horizontal direction in a close contact state in which the mounting surfaces 4d and 12d are overlapped. In this example, a plurality of fastening bolts 40 (four in this case) are provided side by side in the longitudinal direction of the girder 4 to form a fastening bolt row, and the fastening bolt row is an H-shape of the girder 4. For example, two rows are provided across the steel web 4e, but the arrangement is not limited to this example.

  On the other hand, the clamp 50 (corresponding to the “pinching member”) is used for the latter contact, that is, the contact between the attachment surface 15d of the lower attachment plate 15 of the viscoelastic damper 10 and the attachment surface 9d of the horizontal member 9b of the auxiliary member 9. Is done. The clamp 50 has a U-shaped or C-shaped member as a main body, and jack bolts 51 and 51 serving as sandwiching portions are screwed into both end portions 50a and 50a so as to be able to advance and retreat toward the opposite end portions 50a, respectively. Are combined. Therefore, in a state where both the lower mounting plate 15 of the viscoelastic damper 10 and the upper flange 9c of the horizontal member 9b are positioned between the jack bolts 51, 51, the jack bolt 51 is screwed and rotated, Both the lower mounting plate 15 and the upper flange 9c are sandwiched between jack bolts 51 and 51, and overlap and closely contact each other on the mounting surfaces 15d and 9d.

Here, the static frictional force F generated between the mounting surfaces 9d and 15d is adjusted so as to satisfy the following expression 1 by adjusting the pinching force of the jack bolts 51 and 51.
Static friction force F <Assumed load of damage of viscoelastic damper−Static friction force f of clamp f Equation 1

  Note that the “assumed damage load” in the above equation 1 is a load having a magnitude that causes a limit shear strain in the viscoelastic body 17 of the viscoelastic damper 10, for example. Further, the “static frictional force f of the clamp” in the formula 1 is the horizontal static frictional force f1 between the clamp 50 and the viscoelastic damper 10 and the horizontal direction between the clamp 50 and the auxiliary member 9. The smaller frictional force of the static frictional force f2. Specifically, in the example of FIGS. 5A and 5B, the former static friction force f1 is a static friction force between the tip of the jack bolt 51 and the upper surface 15f of the lower mounting plate 15 of the viscoelastic damper 10, and the latter The static frictional force f2 is the smaller of the static frictional force between the tip of the jack bolt 51 and the sliding member 53 or the static frictional force between the sliding member 53 and the lower surface 9f of the upper flange 9c. It is.

  If the static friction force F between the mounting surfaces 9d and 15d is set so as to satisfy the above formula 1, even if a large horizontal force acts on the double floor structure 1 during an earthquake, Before the force exceeding the damage assumed load is applied to the viscoelastic damper 10, the horizontal sliding between the mounting surfaces 9d and 15d is started, whereby the viscoelastic damper 10 is moved to the auxiliary member 9. Will be cut off. As a result, the input of the horizontal force to the viscoelastic damper 10 is suppressed, and the breakage is effectively prevented. That is, a fail safe function is given to the viscoelastic damper 10. In order to reliably reduce the friction coefficient between the mounting surfaces 9d and 15d, a low friction coefficient such as a fluororesin such as PTFE (polytetrafluoroethylene) (for example, Teflon (registered trademark of DuPont, USA)) is used. A sliding material (not shown) may be interposed between the attachment surfaces 9d and 15d.

  A plurality of such clamps 50 (four in this case) are provided side by side in the longitudinal direction of the horizontal member 9b of the auxiliary member 9 (the same direction as the longitudinal direction of the large beam 4) to form a clamp row. For example, the clamp rows are provided in two rows with the H-shaped steel web 9e of the horizontal member 9b interposed therebetween, but the present invention is not limited to this arrangement example. Moreover, as a specific example of the clamp 50, a Bullman C type (trade name: manufactured by Bullman Co., Ltd.) or the like can be given.

  By the way, the above-described clamp 50 is attached across the viscoelastic damper 10 and the auxiliary member 9 via a pair of jack bolts 51, 51. On the other hand, when the large horizontal force is applied, the viscoelastic damper 10 and the auxiliary member 9 are cut off and relatively moved (slid) in the horizontal direction. Therefore, if the jack bolt 51 of the clamp 50 is firmly fixed to both the viscoelastic damper 10 and the auxiliary member 9, the clamp 50 is connected to the viscoelastic damper 10 and the auxiliary member during the above relative movement. 9 may receive a tensile force or the like in the horizontal direction from both of them, thereby causing deformation such as twisting of the clamp 50, or falling off from both of them due to competition. As a result, every time an earthquake occurs, re-installation work such as replacement of the clamp 50 is forced after the earthquake, which is inconvenient.

  Therefore, in order to make the clamp 50 maintenance-free, the friction coefficient relating to the horizontal static frictional force between the clamp 50 and the viscoelastic damper 10 and the horizontal staticity between the clamp 50 and the auxiliary member 9 are eliminated. The friction coefficient related to the frictional force is made different. Thereby, at the time of relative movement of the viscoelastic damper 10 and the auxiliary member 9, the clamp 50 is attached to one of the viscoelastic damper 10 and the auxiliary member 9 based on the above-described friction coefficient difference, and with respect to the other. Will slide quickly. As a result, the deformation and dropping of the clamp 50 as described above can be effectively prevented. Incidentally, the reason why the frictional force should be made different directly is that the friction coefficient only needs to be changed instead. The vertical drags that are the basis of each frictional force are the internal forces of the clamp 50 (similar to the axial force). This is because they are equivalent to each other.

  Specific methods for making these friction coefficients different from each other include roughening or roughening the surface, or using a sliding material having a low friction coefficient such as the above-mentioned fluororesin such as PTFE. In the examples of FIGS. 5A and 5B, the latter method is adopted. That is, as shown in FIG. 5A, the lower end 9f of the upper flange 9c of the horizontal member 9b of the auxiliary member 9 to which the clamping force is to be applied from the front end of one jack bolt 51 of the clamp 50 ("attachment"). The above-mentioned sliding material 53 is interposed between the front end of the jack bolt 51 of the clamp 50 and the clamping force from the front end. The sliding material 53 is not interposed between the upper surface 15f of the lower mounting plate 15 of the viscoelastic damper 10 to be applied (corresponding to “a surface opposite to the mounting surface”). As a result, the coefficient of friction between the clamp 50 and the viscoelastic damper 10 is set to be larger. As a result, the clamp 50 maintains the sandwiching posture during relative movement between the viscoelastic damper 10 and the auxiliary member 9. The viscoelastic damper 10 is securely attached.

  Incidentally, the reason for attaching to the viscoelastic damper 10 is that in the example of FIGS. 5A and 5B, the upper surface 15 f of the lower mounting plate 15 of the viscoelastic damper 10 is higher than the upper flange 9 c of the auxiliary member 9. This is because it is narrower in all horizontal directions than the lower surface 9f. That is, when the jack bolt 51 slides, the probability of dropping from the lower mounting plate 15 of the viscoelastic damper 10 is higher than that of the upper flange 9c of the auxiliary member 9.

  Here, preferably, as shown in FIGS. 6A and 6B, between the lower mounting plate 15 of the viscoelastic damper 10 and the tip of the jack bolt 51 facing this, and the sliding material 53, A pressure receiving plate 55 made of a steel plate having a predetermined thickness may be interposed between the tip of the other jack bolt 51 facing the sliding member 53. The pressure receiving plate 55 is provided for each clamp row, and is formed to have a length over all the clamps 50 belonging to the clamp row. If such a pressure receiving plate 55 is provided, the frictional force distribution generated by the clamp row can be made substantially uniform.

  Further, according to the configuration in which the pressure receiving plate 55 described above is provided, when the existing viscoelastic damper 10 is made maintenance-free and made fail-safe later, the remodeling work can be easily performed. This will be specifically described. FIG. 7A and FIG. 7B are explanatory views of an attached state of the existing viscoelastic damper 10 before the fail-safe remodeling. Usually, the lower mounting plate 15 of the existing viscoelastic damper 10 and the upper flange 9 c of the horizontal member 9 b of the auxiliary member 9 are fastened and fixed by fastening bolts 44. Therefore, the fastening bolts 44 are removed as one work of construction, and then the bolt holes 15h and 9h appear in the lower mounting plate 15 and the upper flange 9c, respectively. Depending on the size of the jack bolt 51 of the clamp 50, the tip end portion of the jack bolt 51 falls into the bolt holes 15h and 9h, thereby preventing the installation of the clamp 50.

  In this regard, as shown in FIGS. 6A and 6B, the pressure receiving plate 55 is formed in a size that covers and closes the bolt holes 15h, 9h, and the pressure receiving plate 55 is connected to the tip of one jack bolt 51. Since the pressure receiving plate 55 prevents the jack bolt 51 from falling if it is interposed between the lower mounting plate 15 and between the tip of the other jack bolt 51 and the sliding member 53, the clamp 50 Installation work can be performed without problems. That is, the workability when the viscoelastic damper 10 is made maintenance and fail-safe is retrofitted.

  Incidentally, the problem relating to the above-described bolt holes 15h and 9h occurs particularly when an interference object is attached to the viscoelastic damper 10 and the installation position of the above-described existing fastening bolt 44 is limited. easy. For example, in the example of FIGS. 7A and 7B, an assembly bolt 19 for assembling a plurality of the vertical plates 16, 16... (Two in the illustrated example) that are parts of the viscoelastic damper 10 is provided in the longitudinal direction of the girder 4. Are provided along a predetermined pitch. For this reason, the existing fastening bolts 44 are installed by changing the positions of these assembly bolts 19, but such a restriction on the installation position is similarly imposed on the clamp 50. That is, the clamp 50 must be disposed at the same position as the position where the fastening bolt 44 is removed. Then, the jack bolt 51 of the clamp 50 is likely to fall into the existing bolt holes 15h, 9h, that is, the installation of the clamp 50 is significantly hindered. Therefore, the above-described pressure receiving plate 55 is particularly effective when there is a restriction on the position where the existing fastening bolts 44 can be installed.

  Incidentally, in the first embodiment described above, as shown in FIGS. 5A and 5B, the upper mounting plate 12 and the large beam 4 of the viscoelastic damper 10 are fastened and fixed by fastening bolts 40 so as not to move relative to each other in the horizontal direction. The lower mounting plate 15 of the viscoelastic damper 10 and the horizontal member 9b of the auxiliary member 9 are mounted so as to be slidable in the horizontal direction by the clamp 50. However, the present invention is not limited to this and may be reversed. . That is, the upper mounting plate 12 and the large beam 4 of the viscoelastic damper 10 are slidably mounted in the horizontal direction by the clamp 50, while the lower mounting plate 15 of the viscoelastic damper 10 and the horizontal member 9b of the auxiliary member 9 are The fastening bolt 40 may be fastened and fixed so as not to be relatively movable in the horizontal direction. Furthermore, the clamp 50 may be applied to both, and both may be attached to be slidable in the horizontal direction.

=== Second Embodiment ===
8A and 8B are explanatory views of the attachment structure of the viscoelastic damper 10 according to the second embodiment. 8A is a side view, and FIG. 8B is a cross-sectional view taken along line BB in FIG. 8A.

  In the first embodiment described above, the viscoelastic damper 10 is slid with respect to the auxiliary member 9 of the vertical surface 7 of the double floor structure 1 in order to prevent a horizontal force from being input to the viscoelastic damper 10 during an earthquake. The second embodiment is different from the first embodiment in that the viscoelastic damper 10 is configured to be slidable with respect to the large beam 4 of the horizontal surface 2. Moreover, the point which does not use the above-mentioned clamp 50 also differs in the method of sticking the attachment surface 12d of the viscoelastic damper 10 to the attachment surface 4d of the large beam 4 of the horizontal construction surface 2. Other configurations are generally the same as those in the first embodiment described above.

  The lower mounting plate 15 of the viscoelastic damper 10 is fastened and fixed to the auxiliary member 9 of the vertical construction surface 7 by fastening bolts 40. Specifically, a fastening bolt 40 is provided by passing both the lower mounting plate 15 of the viscoelastic damper 10 and the upper flange 9c of the horizontal member 9b of the auxiliary member 9 in the vertical direction, and is screwed into the fastening bolt 40. Due to the fastening force of the nut 41, the lower mounting plate 15 and the upper flange 9c are fixed so as not to move relative to each other in the vertical direction and the horizontal direction in a close contact state where the mounting surfaces 15d and 9d are overlapped.

  On the other hand, the upper attachment plate 12 of the viscoelastic damper 10 is attached to the large beam 4 of the horizontal construction surface 2. That is, the upper surface 12d of the upper mounting plate 12 is used as the mounting surface on the viscoelastic damper 10 side, and the lower surface 4d of the lower flange 4a of the main beam 4 is used as the mounting surface on the main beam 4 side. While being slidably attached.

  The sandwiching member 60 for slidably contacting is either one of a bolt 61, a nut 62 screwed to the bolt 61, the lower flange 4a of the large beam 4, or the upper mounting plate 12 of the viscoelastic damper 10. The long hole-shaped bolt hole 4h formed in the upper part, the circular flanged hole 12h formed in the remaining one of the lower flange 4a of the large beam 4 or the upper mounting plate 12, and the fluctuation of the axial force of the bolt 61 are suppressed. A disc spring 63.

  In this example, the long hole-shaped bolt hole 4h is formed through the lower flange 4a of the large beam 4, and the longitudinal direction of the long hole-shaped bolt hole 4h is aligned with the longitudinal direction of the large beam 4. The length is set based on the assumed sliding amount between the mounting surfaces 12d and 4d during the earthquake. On the other hand, the circular bolt hole 12 h is formed through the upper mounting plate 12, and the inner diameter thereof is set to a diameter having a minimum clearance necessary for passing the bolt 61.

  When the bolt 61 is passed through the bolt holes 4h and 12h with the nut 62, the disc spring 63 is interposed between the lower flange 4a and the bolt head portion 61a or the nut 62. A resilient force of 63 is applied to the lower flange 4a and the upper mounting plate 12 of the large beam 4 as a pinching force through the axial force of the bolt 61. For convenience of explanation, it is assumed below that the bolt head 61a is located on the side of the large beam 4 as shown in FIGS. 8A and 8B.

Here, the static frictional force F generated between the mounting surface 4 d of the large beam 4 and the mounting surface 12 d of the upper mounting plate 12 of the viscoelastic damper 10 satisfies the following formula 2 by adjusting the elastic force of the disc spring 63. To be adjusted.
Static friction force F <viscous load of viscoelastic damper-static friction force f of pinching member ... Formula 2

  In addition, the definition of “assumed damage load” in the above formula 2 is the same as described above. Further, the “static frictional force f of the sandwiching member” in the formula 2 is the static frictional force f3 in the horizontal direction between the sandwiching member 60 and the large beam 4 and between the sandwiching member 60 and the viscoelastic damper 10. This is the smaller frictional force of the horizontal static frictional force f4. Specifically, in the example of FIGS. 8A and 8B, the former static friction force f3 is the static friction force between the disc spring 63 and the sliding material 66 or the sliding material 66 and the upper surface 4f of the lower flange 4a of the large beam 4. The latter static friction force f4 is a static friction force between the nut 62 and the lower surface 12f of the upper mounting plate 12 of the viscoelastic damper 10.

  And if the static frictional force between the mounting surfaces 4d and 12d is set so as to satisfy the above formula 2, even if a large horizontal force acts on the double floor structure 1 during an earthquake, Before the force exceeding the damage assumed load is applied to the viscoelastic damper 10, horizontal sliding between the mounting surfaces 4d and 12d is started, whereby the viscoelastic damper 10 and the horizontal construction surface 2 are started. The large beam 4 is cut off. As a result, the input of the horizontal force to the viscoelastic damper 10 is suppressed, and the breakage is effectively prevented. In order to reliably reduce the friction coefficient between the mounting surfaces 4d and 12d, a sliding material having a low friction coefficient such as the above-mentioned fluororesin such as PTFE is interposed between the mounting surfaces 4d and 12d. Good.

  A plurality of such sandwiching members 60 are provided in the longitudinal direction of the girder 4 (four in this case) to form a sandwiching member row. The sandwiching member row is a web of the H-shaped steel of the girder 4. For example, two rows are provided across 4e, but the arrangement is not limited to this example.

  By the way, like the clamp 50 of the first embodiment described above, the sandwiching member 60 is attached across both the viscoelastic damper 10 and the large beam 4 via the disc spring 63 and the nut 62. On the other hand, at the time of the action of the large horizontal force described above, the viscoelastic damper 10 and the large beam 4 are cut off and relatively moved (slid) in the horizontal direction. Therefore, if both the disc spring 63 and the nut 62 of the sandwiching member 60 are firmly fixed to the large beam 4 and the viscoelastic damper 10, respectively, the sandwiching member 60 is In addition, a horizontal tensile force or the like is received from both the girder 4 and the viscoelastic damper 10 so that the bolt 61 of the sandwiching member 60 may be tilted or the like, and may not be sandwiched in a normal vertical posture. The bolt 61 may be damaged by receiving a large shearing force from the hole 12h. As a result, every time an earthquake occurs, re-installation work such as replacement of bolts 61 is forced after the earthquake, which is inconvenient.

  Therefore, in order to achieve maintenance-free operation of the sandwiching member 60, the friction coefficient related to the horizontal static frictional force between the sandwiching member 60 and the large beam 4 is determined in the horizontal direction between the sandwiching member 60 and the viscoelastic damper 10. It is made smaller than the coefficient of friction related to the static frictional force. Thereby, at the time of relative movement of the viscoelastic damper 10 and the girder 4, the sandwiching member 60 is surely attached to the viscoelastic damper 10 based on the above-described friction coefficient difference, and quickly slides with respect to the girder 4. . As a result, problems such as the inclination of the bolt 61 of the sandwiching member 60 and the breakage of the bolt as described above are effectively prevented.

  In addition, as a specific method for making a difference in the above-mentioned friction coefficient, for example, as shown in FIGS. 8A and 8B, the upper surface 4f of the disc flange 63 and the lower flange 4a of the large beam 4 (“the opposite side of the mounting surface”). Between the nut 62 and the lower surface 12f of the upper mounting plate 12 (corresponding to the “opposite surface of the mounting surface”). And the like, and the like that the above-mentioned sliding material 66 is not interposed.

  In addition, according to this clamping member 60, the drop off from the upper mounting plate 12 and the lower flange 4a which could occur in the case of the clamp 50 structure of the first embodiment can never occur, and is excellent in that respect. Further, the friction force between the mounting surfaces 4d and 12d is obtained by utilizing the constant elastic force region of the disc spring 63 (the range of the deflection amount in which the elastic force is maintained substantially constant with respect to the deflection amount variation). It is also excellent in that it can be set to be substantially constant.

=== Other Embodiments ===
As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, The deformation | transformation as shown below is possible in the range which does not deviate from the summary.

  In the above-described embodiment, the H-shaped steel is used for the horizontal member 9b of the auxiliary member 9 related to the horizontal beam 2 and the vertical beam 7, but it corresponds to the flanges 4a and 9c of the H-shaped steel. The steel material is not limited to this as long as it has a horizontal plate portion extending in the horizontal direction at the upper part or the lower part. For example, groove steel or angle steel may be used.

  In the above-described embodiment, the structure of FIG. 2 is exemplified as the double floor structure 1, but the structure is not limited to this, and a double floor structure 1 as shown in FIGS. 9 to 11 may be used. In the following, only the differences will be described, and the other configuration is the same as that of the double floor structure 1 according to the first embodiment.

  In the example of the double floor structure 1 in FIG. 9, auxiliary members 9 having the same structure as that of the first embodiment are used for one of the opposing beams 4 and 4. That is, as the auxiliary member 9, a steel material in which a horizontal member 9b is interposed between a pair of diagonal members 9a, 9a arranged symmetrically in the horizontal direction is used, and the horizontal member 9b of the auxiliary member 9 is damped. It is connected to the middle part of the large beam 4 via the means 10, and each end of the pair of diagonal members 9a, 9a is connected to the lower end of each column 8 that supports both ends of the large beam 4, respectively. Has been.

  Further, second auxiliary members 91 are used for the other beams 4 and 4 facing each other. The second auxiliary member 91 is a steel material in which a horizontal member 9b is fixed to an end portion of the diagonal member 91a. The horizontal member 9b is connected to the portion closer to the end portion in the longitudinal direction than the middle portion of the large beam 4 via the damping means 10, and the end portion of the diagonal member 91a supports the large beam 4. It is connected to the lower end of the column 8.

  In the example of the double floor structure 1 in FIG. 10, a connecting member 91 c is horizontally installed between adjacent columns 8 and 8 that support the large beam 4. The horizontal member 9b of the auxiliary member 9 is connected to the middle portion of the large beam 4 via the damping means 10 with respect to one of the opposite large beams 4 and 4, and the end of the diagonal member 9a It connects with the connection part with the said connection material 91c in each pillar 8 to support.

  For the other beams 4 and 4 facing each other, the horizontal member 9b of the second auxiliary member 91 has a damping means 10 at a portion closer to the end side in the longitudinal direction than the middle portion of the beam 4. The end portion of the diagonal member 91a is connected to the connecting portion of the column 8 supporting the large beam 4 with the connecting member 91c.

  In the example of the double floor structure 1 in FIG. 11, auxiliary members 9 having the same structure as that of the first embodiment are used for one of the opposite beams 4, 4. The third auxiliary members 93 are used for the other beams 4 and 4 facing each other. The third auxiliary member 93 is obtained by increasing the length of the horizontal member 9b of the auxiliary member 9 according to the first embodiment. That is, a pair of oblique members are provided at both ends in the longitudinal direction of the horizontal member 9b. The materials 9a and 9a are fixed. The horizontal members 9b are two portions closer to the end in the longitudinal direction than the intermediate portion of the large beam 4, and are respectively equidistant from the intermediate portion via the attenuation means 10. It is connected. Further, the end portions of the pair of diagonal members 9a, 9a are connected to the lower end portions of the columns 8 that support the large beams 4, respectively.

1 double floor structure, 2 horizontal surfaces,
4 Large beam, 4a Lower flange (mounting part), 4d Bottom surface (mounting surface),
4f Upper surface (surface opposite to the mounting surface), 4e web, 4h bolt hole,
5 beam, 6 floor panel, 7 vertical construction, 8 pillars,
9 Auxiliary member, 9a Diagonal material, 9b Horizontal material, 9c Flange (attachment part),
9d upper surface (mounting surface), 9e web, 9f lower surface (surface opposite to the mounting surface),
10 viscoelastic damper (damping means), 11 upper member,
12 Upper mounting plate (mounting part), 12d Upper surface (mounting surface),
12f bottom surface (surface opposite to the mounting surface), 12h bolt hole,
13 vertical plate, 14 lower member, 15 lower mounting plate (mounting part),
15d mounting surface, 15f upper surface (surface opposite to the mounting surface), 15h bolt hole,
16 Vertical plate, 17 Viscoelastic body, 19 Assembly bolt,
21 upper floor, 25 floor slab, 40 fastening bolt, 41 nut,
44 fastening bolt, 50 clamp, 50a end, 51 jack bolt,
53 sliding material, 55 pressure receiving plate, 60 sandwiching member,
61 bolt, 61a head, 62 nut, 66 sliding material,
91 auxiliary member, 91a diagonal material, 91c binder material, 93 auxiliary member,
S clearance, SP space,

Claims (6)

It is a double floor structure installed at the top of the floor slab of the building frame,
A horizontal construction surface disposed horizontally above the floor slab with a predetermined interval;
A vertical surface that is installed on top of the floor slab and supports the horizontal surface;
Attenuating means interposed between the horizontal surface and the vertical surface to attenuate the vibration in the vertical direction of the horizontal surface;
The attachment surface of the attachment portion of the attenuation means is attached to be slidable in the horizontal direction with respect to the attachment surface of the attachment portion of at least one of the horizontal composition surface and the vertical composition surface,
A gripping member that abuts the mounting portion of the construction surface and the mounting portion of the attenuation means on the opposite side of the mounting surface and sandwiches the mounting portions,
The friction coefficient related to the horizontal friction force between the sandwiching member and the mounting portion of the construction surface and the friction coefficient related to the horizontal friction force between the sandwiching member and the mounting portion of the damping means are Double floor structure characterized by differences. The double floor structure according to claim 1,
The mounting portion of the construction surface is wider in the horizontal direction than the mounting portion of the attenuation means,
The friction coefficient related to the frictional force in the horizontal direction between the sandwiching member and the mounting portion of the damping means is larger than the friction coefficient related to the frictional force in the horizontal direction between the sandwiching member and the mounting portion of the construction surface. Double floor structure characterized by being larger. The double floor structure according to claim 1 or 2,
The sandwiching member has a pair of sandwiching portions opposed to each other with a gap between them at both ends of the U-shaped or C-shaped member, and at least one of the pair of sandwiching portions serves as the other sandwiching portion. A double floor structure characterized by being a clamp that can be moved forward and backward. The double floor structure according to claim 3,
Between the one sandwiching portion provided in the sandwiching member and the attachment portion of the construction surface, and between the other sandwiching portion provided in the sandwiching member and the attachment portion of the damping means, A double floor structure characterized in that a plate-like member having a size for closing an existing bolt hole is interposed. The double floor structure according to any one of claims 1 to 4,
The damping means is fastened and fixed in a non-slidable manner in the horizontal direction by fastening bolts on the construction surface which is not one of the horizontal construction surface and the vertical construction surface. And double floor structure. The double floor structure according to any one of claims 1 to 5,
The vertical construction surface includes an auxiliary member that does not bear a long-term load and a short-term load excluding its own weight in design,
A double floor structure characterized in that the damping means is interposed between the auxiliary member and the horizontal surface.

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