JP2009174120A - Ceiling structure, method of constructing ceiling structure, and building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceiling structure capable of reducing a heavy floor impact noise by a simple construction from a lower story room, and also to provide a method of constructing the ceiling structure and a building having the ceiling structure. <P>SOLUTION: A ceiling member 44 is installed below a floor slab 12. A damping device 30 comprising a weight member 16 and a viscoelastic body 26 is installed on the upper surface of the ceiling member 44. When the heavy floor impact noise is generated above the floor slab 12, the noise is transmitted to the ceiling member 44. The vibration of the ceiling member 44 is suppressed by the damping effect of the damping device 30, and the heavy floor impact noise emitted from the ceiling member 44 into a lower story room R<SB>1</SB>is reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a ceiling structure for reducing floor impact sound of a building, a method for constructing the ceiling structure, and a building having the ceiling structure.

  When a person jumps or drops an object on the upper floor of a building such as an apartment house and the floor slab vibrates, a floor impact sound is generated on the lower floor, which becomes a problem.

The most common way to reduce floor impact sound is to increase the thickness of the floor slab. Currently, the thickness of the floor slab is often set to 200 mm or more, and in buildings that take into account sound insulation, the thickness is set to 300 mm or more. Sano floor slabs may be used.
However, when the thickness of the floor slab is increased, the load of the floor slab increases, and in order to support the load, it is necessary to further increase the structural cross section of columns and beams.

Further, as a conventional technique for reducing floor impact sound by a dry double floor, as shown in FIG. 21, a floor portion 306 in which a flooring 304 and a particle board 302 are vertically stacked is supported on a floor slab 312 by support legs 308. The floor impact sound is absorbed by the cushion rubber 310 attached to the lower end of the support leg 308.
However, the method of absorbing floor impact sound with a material having high sound absorption properties such as cushion rubber 310 is effective in reducing light floor impact sound, but the floor slab thickness is increased for heavy floor impact sound. A sufficient vibration reduction effect cannot be expected as compared with the method to do this.

  In addition, the conventional technology that reduces floor impact noise by using a dry double floor is a dry double floor on the upper floor that is not owned by the residents on the lower floor in order to improve the comfort of the lower floor of this dry double floor. Measures must be taken to reduce floor impact noise. Therefore, it is difficult to introduce this technology into a building that has already been occupying.

Moreover, as a prior art which reduces a floor impact sound with a ceiling board, the method of increasing the mass of a ceiling part by laminating | stacking a ceiling board is mentioned.
However, the method of overlaying the ceiling boards is troublesome because many ceiling boards must be installed above the room.

Further, as a conventional technique for reducing floor impact sound by a ceiling board, a method of installing a sound absorbing material on the back surface (upper surface) of the ceiling board has been proposed (Patent Document 1).
As shown in FIG. 22, the lower-floor building unit 314 that forms the first floor of the unit type building of Patent Document 1 includes four columns 316 and four ceiling beams 318 </ b> A and 318 </ b> B that connect the upper ends of the columns 316. And four floor beams 320 </ b> A and 320 </ b> B that connect the lower ends of the columns 316 to each other. A plurality of field edges 322 are bridged between the facing ceiling beams 318 </ b> B, and a ceiling surface material 324 is fixed to the field edges 322.
In addition, on the back surface (upper surface) of the ceiling surface material 324, a planar vibration damping material 326 in which a plywood and a sound insulating mat such as heavy rubber are vertically stacked is installed.

And this damping material 326 can prevent noise transmission from the upper floor to the lower floor of the unit type building and improve the sound insulation.
However, since the vibration damping material 326 is a planar heavy object, the work of installing the vibration damping material 326 on the ceiling surface material 324 is complicated.
JP 2001-214466 A

  In consideration of such facts, the present invention provides a ceiling structure capable of reducing heavy floor impact sound by simple construction from a lower floor room, a method for constructing the ceiling structure, and a building having the ceiling structure. This is the issue.

  The invention according to claim 1 is a ceiling member provided below a floor slab to form a ceiling surface, a weight member attached to an upper surface or a lower surface of the ceiling member via a viscoelastic body, and the viscoelastic body. And a vibration damping device comprising:

  In the invention described in claim 1, a ceiling member is provided below the floor slab to form a ceiling surface. A weight member is attached to the upper or lower surface of the ceiling member via a viscoelastic body, and the weight member and the viscoelastic body constitute a vibration damping device.

When a heavy floor impact sound is generated above the floor slab, and this heavy floor impact sound is transmitted to the floor slab, the heavy floor impact sound transmitted to the floor slab becomes a solid propagation sound or air propagation sound and the ceiling. It is transmitted to the member.
The vibration of the ceiling member due to this is suppressed by the damping effect of a damping device (TMD: Tuned Mass Damper) composed of a weight member and a viscoelastic body, and is thereby radiated from the ceiling member to the lower floor room. Heavy floor impact noise is reduced.

  For example, when a dry double floor is arranged on a floor slab and a heavy floor impact sound is generated on the dry double floor, the heavy floor impact sound is suspended by hanging the dry double floor, the floor slab, and the ceiling member. The member is transmitted as a solid propagation sound and reaches the ceiling member. Further, the heavy floor impact sound is transmitted as air-propagating sound through the floor space of the dry double floor and the ceiling space formed between the floor slab and the ceiling surface and reaches the ceiling member. These sounds reaching the ceiling member are combined and radiated from the ceiling member to the lower floor room.

Therefore, the vibration of the ceiling member has various dominant frequencies such as dry double floor, floor space, floor slab, suspension member, ceiling space, and ceiling member. Therefore, for example, even if a vibration control device is installed on the floor slab to reduce the dominant frequency of the floor slab, if other dominant frequencies dominate the vibration characteristics of the ceiling member, The sound radiated to the room on the floor cannot be reduced sufficiently.
On the other hand, in the ceiling structure according to claim 1, the ceiling member in which various dominant frequencies exist by finally providing a vibration damping device on the ceiling member which is a member that radiates heavy floor impact sound in the lower floor room. Therefore, the heavy floor impact sound can be effectively reduced.

Moreover, since a weight member should just be attached to the upper surface or lower surface of a ceiling member via a viscoelastic body, comfortability can be improved from the room of a lower floor.
Therefore, when the ceiling structure of claim 1 is introduced, the upper floor occupants who have already moved in are not disturbed.

  Further, in the vibration damping device, the larger the mass ratio μ (= m / M) indicating the ratio of the mass of the vibration damping device (the mass m of the weight member) to the mass to be controlled for vibration (the mass M of the ceiling member). A great vibration reduction effect can be obtained.

Here, since the mass of the ceiling member is smaller than that of the floor slab, a predetermined mass ratio μ (vibration reduction effect) can be obtained by a weight member having a smaller mass than when the vibration damping device is provided on the floor slab.
Therefore, since a light weight member may be attached to the upper surface or the lower surface of the ceiling member, construction is simple and a low-cost ceiling structure can be constructed.

  In addition, a mass member with a mass of several kilograms has a sufficiently large mass ratio μ, so it is included in the vibration of the ceiling member (such as dry double floor, floor space, floor slab, suspension member, ceiling space, and ceiling member). When the dominant dominant frequency deviates from the natural frequency of the vibration control device, the vibration reduction performance of the vibration control device is high.

  Therefore, it is possible to exhibit the vibration reduction effect in the wide band. For example, in a general housing complex, there are many different dominant frequencies in the 63 Hz band (45 Hz to 90 Hz), and some of these dominant frequencies deviate from the natural frequency of the vibration control device. However, even in such a case, the vibration reduction effect can be exhibited for all frequencies in the 63 Hz band.

  According to a second aspect of the present invention, the ceiling member is suspended from a plurality of bar-like members provided on the floor slab or beam, and the vibration damping device is flat across the entire ceiling surface in a plan view. It is characterized by being arranged in the middle between the lower end position of one of the rod-shaped members adjacent to each other and the lower end position of the other rod-shaped member.

  In the invention described in claim 2, the ceiling member is suspended from a plurality of bar-like members provided on the floor slab or the beam. And the damping device is arrange | positioned in the intermediate | middle between the lower end part position of the one rod-shaped member adjacent in planar view and the lower end part position of the other rod-shaped member over the whole ceiling surface by planar view.

The vibration damping device can effectively reduce vibration by being arranged at the antinode position of the vibration mode.
However, it is difficult to specify the position of the antinode of the vibration mode generated in the ceiling member suspended below the floor slab. Moreover, when specifying the position of the antinode of the vibration mode by vibration measurement, it takes several hours of measurement time for each room, so it is laborious to measure the vibration of all the rooms in an apartment house with many rooms. .

  On the other hand, in the ceiling structure of the second aspect, the ceiling member does not vibrate so much at the lower end position of the bar-like member, and therefore the vibration damping device is arranged at a planar position other than the lower end part position of the bar-like member. That is, the vibration damping device is arranged between the lower end position of one rod-shaped member adjacent in plan view and the lower end position of the other rod-shaped member. Thereby, a damping device can be arranged at an effective position for vibration reduction.

  Further, this arrangement (arrangement of the vibration damping device in the middle between the lower end position of one bar-shaped member adjacent to the other in plan view and the lower end position of the other bar-shaped member) is performed over the entire ceiling surface in plan view. Therefore, a lot of vibration control devices are arranged near the position of the antinode of the vibration mode generated in the ceiling member or near the position of the antinode of the vibration mode, and the weight impact sound can be reduced more effectively. .

  Moreover, since many weight members are arrange | positioned in a ceiling member by arrange | positioning a damping device over the whole ceiling surface by planar view, the mass ratio of the mass total of the weight member with respect to the total mass of a ceiling member becomes large. As a result, a large vibration reduction effect is obtained and the robustness of vibration reduction is increased.

  According to a third aspect of the present invention, the vibration damping device is disposed at the center between the lower end position of one of the rod-shaped members adjacent to each other in plan view and the lower end position of the other rod-shaped member. It is a feature.

In the invention according to claim 3, the vibration damping device is arranged at the center between the lower end position of one of the rod-shaped members adjacent to each other in plan view and the lower end position of the other rod-shaped member.
Therefore, the center of the lower end position of one rod-like member adjacent to the other in the plan view and the lower end position of the other rod-like member is often the position of the antinode of the primary mode. Therefore, the vibration control device can be arranged at a more effective position for vibration reduction.

  The invention according to claim 4 is characterized in that the vibration damping device is uniformly arranged over the entire area of the ceiling surface in a plan view.

In the invention according to claim 4, the vibration damping device is uniformly arranged over the entire area of the ceiling surface in plan view.
The vibration damping device can effectively reduce vibration by being arranged at the antinode position of the vibration mode.
However, it is difficult to specify the position of the antinode of the vibration mode generated in the ceiling member provided below the floor slab. Moreover, when specifying the position of the antinode of the vibration mode by vibration measurement, it takes several hours of measurement time for each room, so it is laborious to measure the vibration of all the rooms in an apartment house with many rooms. .

  On the other hand, in the ceiling structure of claim 4, since the vibration damping device is uniformly arranged over the entire ceiling surface in a plan view, the position of the vibration mode antinode generated in the ceiling member or the vibration mode antinode A lot of vibration control devices are arranged near the position, and the heavy floor impact sound can be effectively reduced.

  In addition, because the arrangement of the damping device is effective for various vibration modes, the joints such as the members (field edge, field edge receiver) and the suspension members that constitute the ceiling member, and the construction of the ceiling member This is particularly effective when it is difficult to specify the vibration mode properties of the ceiling member due to an error or the like.

  In addition, since the vibration damping device is not arranged based on the position of the suspension member, for example, when a small beam is placed between structural members such as walls and beams and the ceiling surface material is fixed to the small beam In addition, even when the lower end portion of the suspension member vibrates due to the use of a suspension member having low rigidity, the position where the vibration damping device is disposed can be determined.

  Moreover, since many weight members are arrange | positioned in a ceiling member by arrange | positioning a damping device over the whole ceiling surface by planar view, the mass ratio of the mass total of the weight member with respect to the total mass of a ceiling member becomes large. As a result, a large vibration reduction effect is obtained and the robustness of vibration reduction is increased.

  According to a fifth aspect of the present invention, the vibration acceleration of the ceiling member is measured by generating a heavy floor impact sound above the floor slab, and the control is performed at the position of the ceiling member where the vibration acceleration becomes a predetermined value or more. A vibration device is arranged.

  According to the fifth aspect of the present invention, a heavy floor impact sound is generated above the floor slab, and the vibration acceleration of the ceiling member at this time is measured. Further, the vibration damping device is arranged at the position of the ceiling member where the measured vibration acceleration is equal to or greater than a predetermined value.

  Therefore, by arranging the vibration damping device at the position of the ceiling member where the measured vibration acceleration is equal to or higher than a predetermined value, it is possible to reliably reduce the heavy floor impact sound of the vibration acceleration higher than the predetermined value generated in the ceiling member. .

  In addition, since the vibration mode can be accurately identified, it becomes possible to arrange the vibration control device only at the position of the ceiling member where the vibration acceleration needs to be reduced, thereby reducing the number of vibration control devices to be installed. it can.

  In the invention according to claim 6, the mass of the weight member and the spring constant of the viscoelastic body are selected so that the center frequency of a predetermined frequency band and the natural frequency of the damping device are substantially equal. It is characterized by that.

  In the invention according to claim 6, since the mass of the weight member and the spring constant of the viscoelastic body are selected so that the center frequency of the predetermined frequency band and the natural frequency of the vibration damping device are substantially equal, The heavy floor impact sound at the center frequency can be reduced.

  Further, since the mass ratio μ (= m / M) can be increased to increase the vibration reduction robustness of the vibration damping device, it is possible to reduce the heavy floor impact sound in a predetermined frequency band near the center frequency. it can.

  The invention according to claim 7 is characterized in that the predetermined frequency band is a 63 Hz band or a 125 Hz band.

  In the invention according to claim 7, by setting the predetermined frequency band to the 63 Hz band or the 125 Hz band, the heavy floor impact sound in the 63 Hz band or 125 Hz band which is a problem in particular among the heavy floor impact sounds is reliably reduced. be able to.

Recommended measurement standard of the Architectural Institute of Japan “Measurement method of floor impact sound level at building site” or JIS-A-1418-2: 2000 “Measurement method of floor impact sound insulation performance of building—Part 2: Standard weight The grade shown in JIS-A-1419-2 “Evaluation method of sound insulation performance of buildings and building materials-Part 2: Floor impact sound insulation performance” When evaluating against a curve, the heavy floor impact sound level generated in a general building increases in the 63 Hz and 125 Hz bands, and this sound insulation rating often determines the evaluation of habitability (see FIGS. 15 and 16). ).
Therefore, reducing the heavy floor impact sound in the 63 Hz band or 125 Hz band is effective in improving comfortability.

  The invention according to claim 8 has a wall surface material that forms a wall space that partitions a lower floor room of the floor slab and connects to a ceiling space formed between the floor slab and the ceiling surface, A weight member is attached to the surface of the material via a viscoelastic body.

  In the invention described in claim 8, the wall space partitioning the lower floor room of the floor slab is formed by the wall material. The wall space is connected to a ceiling space formed between the floor slab and the ceiling surface. And the weight member is attached to the surface of the wall material through a viscoelastic body.

  The heavy floor impact sound radiated to the ceiling space formed between the floor slab and the ceiling surface is transmitted to the wall material through the wall space connected to the ceiling space. And a heavy-weight floor impact sound is radiated | emitted from the wall surface material to the room of the lower floor of a floor slab, and this may cause a habitability deterioration.

  On the other hand, in the ceiling structure of the eighth aspect, the vibration of the wall surface material is suppressed by the vibration damping device (wall TMD) made of the weight member and the viscoelastic body, thereby radiating from the wall surface material to the lower floor room. Sound can be reduced.

  The invention according to claim 9 is the construction method of the ceiling structure for constructing the ceiling structure according to any one of claims 1 to 8, wherein the vibration damping device is attached to a ceiling surface material constituting the ceiling member. It is characterized by having a vibration damping device installation step and a ceiling surface material installation step in which the ceiling surface material is provided below the floor slab after the vibration damping device installation step to form a ceiling surface.

  In the invention according to claim 9, before the ceiling surface material installation step of forming the ceiling surface by providing the ceiling surface material below the floor slab, the vibration damping device installation step of attaching the vibration damping device to the ceiling surface material is performed. Therefore, it is possible to perform installation work of the vibration damping device in a place where the vibration damping device can be easily attached to the ceiling surface material.

  Invention of Claim 10 is the construction method of the ceiling structure which construct | assembles the ceiling structure of any one of Claims 1-8, The ceiling surface material which comprises the said ceiling member is below the said floor slab. And a ceiling surface material installation step for forming a ceiling surface, and a vibration damping device installation step for attaching the vibration damping device to the ceiling surface material after the ceiling surface material installation step.

In the invention described in claim 10, before the vibration damping device installation step of attaching the vibration damping device to the ceiling surface material, the ceiling surface material installation step of forming the ceiling surface by providing the ceiling surface material below the floor slab is performed. Therefore, when installing the vibration control device to the ceiling surface material for renovation work after the ceiling surface material is installed below the floor slab, the vibration control device can be installed on the ceiling without removing the ceiling surface material to which the vibration control device is attached. Can be attached to face material.
That is, after removing only the ceiling surface material close to the ceiling surface material to which the vibration damping device is attached, the vibration damping device may be attached to the ceiling surface material that has not been removed, and the removed ceiling surface material may be restored. By repeating this work, the vibration control device can be installed with the minimum construction range.

  The invention described in claim 11 has the ceiling structure described in any one of claims 1-8.

  In invention of Claim 11, the building which has a ceiling structure which reduces a heavy floor impact sound by simple construction from the room of a lower floor can be constructed | assembled.

  Since the present invention is configured as described above, heavy floor impact noise can be reduced by simple construction from a lower floor room.

  The ceiling structure of the present invention, the construction method of the ceiling structure, and the building will be described with reference to the drawings. In the present embodiment, an example in which the present invention is applied to a suspended ceiling having a structure in which the ceiling member is suspended by a suspension tree provided on the floor slab or the beam is shown, but various ceiling members are provided below the floor slab. For example, the present invention can be applied to a system ceiling. Further, the present embodiment can be applied to new buildings and renovated buildings.

  First, a first embodiment of the present invention will be described.

As shown in FIG. 1, in the ceiling structure 10 of the first embodiment, a ceiling member 44 is provided below the floor slab 12, thereby forming a ceiling surface 28. The ceiling member 44 includes a ceiling board 14 as a ceiling surface material, a field edge 24, and a field edge receiver 22.
The ceiling board 14 is a gypsum board having a density of 0.65 ton / m ³ and a thickness of 0.95 cm.

  A TMD (Tuned Mass Damper) 30 as a vibration damping device is installed on the back surface (upper surface) side of the ceiling member 44. The TMD 30 includes a weight member 16 attached to the upper surface of the ceiling board 14 via a viscoelastic body 26 and a viscoelastic body 26.

The weight member 16 is a 3 cm thick iron plate having a square shape of 6.5 cm in length and 6.5 cm in width when seen in a plan view, and has a mass of 1 kg.
The viscoelastic body 26 is a thermoplastic elastomer having a square shape with a length of 2.5 cm and a width of 2.5 cm in a plan view and a thickness of 0.7 cm, and is positioned at the center of the weight member 16 in a plan view. Has been placed.

  The upper surface of the viscoelastic body 26 and the lower surface of the weight member 16, and the lower surface of the viscoelastic body 26 and the upper surface of the ceiling board 14 are bonded by the adhesive force of the viscoelastic body 26 itself. Note that other methods may be used for bonding the upper surface of the viscoelastic body 26 and the lower surface of the weight member 16 and the lower surface of the viscoelastic body 26 and the upper surface of the ceiling board 14.

  In the case of an adhesive method using an adhesive, the natural frequency of the TMD 30 varies depending on the size of the adhesive surface to which the adhesive is applied. Therefore, the adhesive must be uniformly applied to the upper and lower surfaces of the viscoelastic body 26. . Therefore, the bonding method can reliably obtain a uniform bonding force on the entire upper and lower surfaces of the viscoelastic body 26, as in the method of bonding with the adhesive force of the viscoelastic body 26 itself shown in the present embodiment. It is preferable to use the method. For example, a TMD unit constructed by providing a viscoelastic body 26 between a weight member 16 and a steel fixing plate and vulcanizing and bonding the viscoelastic body 26 to the weight member 16 and the fixing plate is used as a ceiling board. 14 may be attached.

  In the TMD 30, the mass of the weight member 16 and the spring constant of the viscoelastic body 26 are selected so that the center frequency of the 63 Hz band and the natural frequency of the TMD 30 are substantially equal.

  A square member 18 is fixed to the lower surface of the floor slab 12, and an upper end portion of a hanging tree 20 as a rod-like member is fixed to the square member 18 and is suspended substantially vertically. Further, a field edge receiver 22 is fixed substantially horizontally at the lower end of the hanging tree 20, and a field edge 24 is fixed substantially horizontally on the lower surface of the field edge receiver 22. The field edge receiver 22 and the field edge 24 are arranged so as to be substantially orthogonal in a plan view. A plurality of ceiling boards 14 are attached to the lower surface of the field edge 24 with nails or the like. That is, the ceiling member 44 is suspended by the plurality of suspension trees 20.

On the floor slab 12, a floor portion 36 in which a flooring 32 and a particle board 34 are vertically stacked is supported by support legs 38.
As shown in the plan view of FIG. 2 in which the ceiling structure 10 is viewed downward from the floor slab 12 side, a ceiling surface 28 is formed by a plurality of ceiling boards 14 laid out. The suspended tree 20 is arranged at a pitch of 909 mm in the horizontal direction (long side direction of the ceiling surface 28) and 1,000 mm in the vertical direction (short side direction of the ceiling surface 28) with respect to the ceiling surface 28. Yes.

The TMD 30 is disposed over the entire area of the ceiling surface 28 in plan view and at the center between the lower end position of one suspension tree 20 and the lower end position of the other suspension tree 20 that are adjacent in plan view.
Moreover, the ceiling board 14 arrange | positioned at the short side outer periphery of the ceiling surface 28 is fixed to a wall via the field edge 24, and the ceiling board 14 arrange | positioned at the long side outer periphery of the ceiling surface 28 is shown in FIG. As shown in the front view, it is fixed to a square member 42 provided on the wall 40 via a field edge 24.

  As shown in FIG. 2, the TMD 30 has a fixed position (a position of the square member 42 provided on the outer periphery on the long side of the ceiling surface 28 or a field provided on the outer periphery on the short side of the ceiling surface 28 in a plan view. The position of the edge 24) and the lower end position of the hanging tree 20 are arranged at the center.

For convenience of explanation, the TMDs 30 arranged in the uppermost row in FIG. 2 are designated as TMDs 30A _{1 to} 30A ₁₃ in order from left to right, and the TMDs 30 arranged in the second row from the top are arranged in order from left to right TMD 30B ₁ , 30B ₃ , 30B ₅ , 30B ₇ , 30B ₉ , 30B ₁₁ , 30B ₁₃ , TMD 30 arranged in the third column from the top is TMD 30C _{1 to} 30C ₁₃ in order from left to right, and TMD 30 arranged in the fourth column from the top TMD 30D ₁ , 30D ₃ , 30D ₅ , 30D ₇ , 30D ₉ , 30D ₁₁ , 30D ₁₃ are sequentially set from left to right, and TMDs 30 arranged in the bottom row are TMD 30E _{1 to} 30E ₁₃ sequentially from left to right.

Then, as described above, the center between the lower end position of one hanging tree 20 adjacent to the other hanging tree 20 and the lower end position of the other hanging tree 20 in plan view, and the fixed position (position of the square member 42 in plan view). Or TMD 30A _{1 to} 30A ₁₃ , 30C _{1 to} 30C ₁₃ , 30E _{1 to} 30E ₁₃ are arranged in the lateral direction (ceiling). in the long side direction) of the surface 28 are arranged at a pitch of _{454.5mm, TMD30B 1, 30B 3,} 30B 5, 30B 7, 30B 9, 30B 11, 30B 13, 30D 1, 30D 3, 30D 5, 30D 7, 30D ₉ , 30D ₁₁ , and 30D ₁₃ are arranged at a pitch of 909 mm in the horizontal direction (long side direction of the ceiling surface 28).

_{Further, TMD30A 1 ~30E 1, 30A 3} ~30E 3, 30A 5 ~30E 5, 30A 7 ~30E 7, 30A 9 ~30E 9, 30A 11 ~30E 11, 30A 13 ~30E 13, the vertical direction (the ceiling TMD 30A ₂ , 30C ₂ , 30E ₂ , 30A ₄ , 30C ₄ , 30E ₄ , 30A ₆ , 30C ₆ , 30E ₆ , 30A ₈ , 30C ₈ , 30E ₈ , 30A ₁₀ , 30C ₁₀ , 30E ₁₀ , 30A ₁₂ , 30C ₁₂ , 30E ₁₂ are arranged at a pitch of 1,000 mm in the vertical direction (the short side direction of the ceiling surface 28).

  Next, the operation and effect of the first embodiment of the present invention will be described.

  In the first embodiment, as shown in FIG. 1, when a heavy floor impact sound is generated on the floor portion 36 supported on the floor slab 12 and the heavy floor impact sound is transmitted to the floor slab 12. The heavy floor impact sound transmitted to the floor slab 12 is transmitted to the ceiling member 44 as solid propagation sound or air propagation sound.

The vibration of this by the ceiling member 44 (the ceiling board 14) is suppressed by the attenuation effect of TMD30 constituted by a weight member 16 and the viscoelastic body 26, whereby the lower floor of the room _{R 1} from the ceiling board 14 Radiated heavy floor impact sound is reduced.

  In addition, since the mass of the weight member 16 and the spring constant of the viscoelastic body 26 are selected so that the center frequency of the 63 Hz band and the natural frequency of the TMD 30 are approximately equal to each other in the TMD 30, In particular, a heavy floor impact sound having a center frequency in the 63 Hz band can be reduced.

Recommended measurement standard of the Architectural Institute of Japan “Measurement method of floor impact sound level at building site” or JIS-A-1418-2: 2000 “Measurement method of floor impact sound insulation performance of building—Part 2: Standard weight The grade shown in JIS-A-1419-2 “Evaluation method of sound insulation performance of buildings and building materials-Part 2: Floor impact sound insulation performance” When evaluating against a curve, the heavy floor impact sound level generated in a general building increases in the 63 Hz and 125 Hz bands, and this sound insulation rating often determines the evaluation of habitability (see FIGS. 15 and 16). ).
Therefore, reducing the heavy floor impact sound in the 63 Hz band or 125 Hz band is effective in improving comfortability.

In addition, the heavy floor impact sound generated on the floor portion 36 is transmitted as a solid propagation sound through the floor portion 36, the support leg 38, the floor slab 12, and the suspension tree 20 and reaches the ceiling member 44. Furthermore, the heavy floor impact sound becomes air propagation sound in the floor space 46 formed between the floor portion 36 and the floor slab 12 and the ceiling space 48 formed between the floor slab 12 and the ceiling surface 28. And reaches the ceiling member 44. Then, these sounds reaching the ceiling member 44 is radiated into the room R ₁ of the lower floor from the ceiling board 14 together.

Therefore, the vibration of the ceiling member 44 includes various dominant frequencies of the floor portion 36, the support leg 38, the floor space 46, the floor slab 12, the suspended tree 20, the ceiling space 48, and the ceiling member 44. Thus, for example, even if a TMD is installed on the floor slab 12 to reduce the dominant frequency of the floor slab 12, if the other dominant frequency dominates the vibration characteristics of the ceiling member 44, the ceiling board 14 it is impossible to sufficiently reduce the sound radiated into the room R ₁ of the lower floor from.

In the ceiling structure 10 of the first embodiment with respect to this, and finally to the ceiling member 44 is a member that emits heavy floor impact sounds to the room R ₁ of Shitakai (ceiling board 14) different by providing TMD30 Since the vibration of the ceiling member 44 having a high dominant frequency is reduced, the heavy floor impact sound can be effectively reduced.

Further, since the may be attached to weight member 16 on the upper surface of the ceiling member 44 (the ceiling board 14) via the viscoelastic body 26 can improve the comfort of the room R ₁ of the lower floor.
Therefore, when introducing the ceiling structure 10 of the first embodiment, is not applied disturb tenants upstairs room R ₂ have already tenants.

Here, as shown in FIG. 4, the vibration analysis model 50 of the ceiling structure 10 is a model in which a ceiling model 52 and a TMD model 54 are connected in series.
The ceiling model 52 is a model in which the spring constant K ₁ and the damping constant C ₁ are connected in parallel, and the mass M of the ceiling member 44 is connected in series thereto.
The TMD model 54 is a model in which a spring constant K ₂ and a damping constant C ₂ are connected in parallel, and the mass m of the weight member 16 is connected in series thereto.

  Then, when vibration acceleration is input to the vibration analysis model 50 of the ceiling structure 10, vibrations having vibration acceleration values 56B to 56E are output for each frequency of the ceiling member 44, as shown in FIG.

When the output value when not installed TMD30 on the ceiling member 44 is placed TMD30 on the ceiling member 44 becomes a value 56A having a peak of vibration acceleration in the frequency _{Q 1,} the output value of the value 56B～56E (vibration reduction effect) can get. In the order of the values 56B, 56C, 56D, and 56E, the value of the mass ratio μ (= m / M) indicating the ratio of the mass m of the weight member 16 to the mass M of the ceiling member 44 increases.

  That is, the TMD 30 increases as the mass ratio μ (= m / M) indicating the ratio of the mass of the TMD 30 (the mass m of the weight member 16) to the mass to be controlled for vibration (the mass M of the ceiling member 44) increases. A vibration reduction effect can be obtained.

  Therefore, since the mass M of the ceiling member 44 is smaller than that of the floor slab 12, a predetermined mass ratio μ (vibration reduction effect) can be obtained by the weight member 16 having a smaller mass than when the TMD 30 is provided on the floor slab 12. . Thereby, since the light weight member 16 should just be attached to the upper surface of the ceiling member 44, construction is easy and the low-cost ceiling structure 10 can be constructed | assembled.

  Further, even the weight member 16 of about several kg has a sufficiently large mass ratio μ, so that it is included in the vibration of the ceiling member 44 (double floor (floor portion 36, support leg 38), floor space 46, floor slab 12, suspended. The robustness of TMD 30 vibration reduction is high when various dominant frequencies (such as wood 20, ceiling space 48, and ceiling member 44) deviate from the natural frequency of TMD 30.

FIGS. 6A and 6B show examples of vibration acceleration output for each frequency of the ceiling member 44 when vibration acceleration is input to the ceiling structure 10.
As shown in FIG. 6 (a), the ceiling member 44 in which the output value when not installed TMD30 is the value 58A having a peak of vibration acceleration in the frequency Q _1, the output value of the value 58B is obtained (a value H A TMD 30 having a mass ratio μ (= m / M) that exhibits a vibration reduction effect of ₁ is installed, and vibration having a vibration acceleration peak is input to the ceiling structure 10 at a frequency Q ₂ that deviates from the frequency Q _1. If it is, the output value at this time (vibration reducing effect on the value 58B value H ₂ reduction) values 58C becomes not sufficient vibration damping effect.

  Such a phenomenon can also occur when the natural frequency of the ceiling board 14 itself deviates. For example, the natural frequency of the ceiling board 14 may easily deviate due to a difference in the pitch at which the suspension tree 20 is arranged or the degree of fixing of the end of the ceiling board 14.

In contrast, as shown in FIG. 6 (b), the ceiling member 44 in which the output value when not installed TMD30 is the value 58A having a peak of vibration acceleration in the frequency Q _1, to give an output value of the value 58D The TMD 30 having a large mass ratio μ (= m / M) (which exhibits the vibration reduction effect of the value H ₃ ) is installed, and the vibration acceleration peak at the frequency Q ₂ deviated from the frequency Q _{1 in the} ceiling structure 10. when vibration having a is input, the output value at this time (vibration reducing effect value H ₄ decreases for values 58D) value 58E becomes sufficient vibration reducing effect is obtained.

  As described above, since the ceiling structure 10 of the first embodiment can secure a large mass ratio μ, it is possible to improve the robustness of vibration reduction, thereby causing the wideband to exhibit the vibration reduction effect. Can do.

  In the first embodiment, since the natural frequency of the TMD 30 is set to the center frequency of the 63 Hz band, the mass ratio μ (= m / M) is increased to increase the robustness of vibration reduction of the TMD 30 to increase the 63 Hz band. The heavy floor impact sound can be reduced.

  In a general housing complex, there are many different dominant frequencies in the 63 Hz band (45 Hz to 90 Hz), and some of these dominant frequencies may deviate from the natural frequency of TMD30. Even in such a case, the vibration reduction effect can be exhibited for all frequencies in the 63 Hz band.

Moreover, TMD30 can reduce a vibration effectively by arrange | positioning in the position of the antinode of vibration mode.
However, it is difficult to specify the position of the antinode of the vibration mode generated in the ceiling member 44 suspended below the floor slab 12. Moreover, when specifying the position of the antinode of the vibration mode by vibration measurement, it takes several hours of measurement time for each room, so it is laborious to measure the vibration of all the rooms in an apartment house with many rooms. .

  On the other hand, in the ceiling structure 10 of the first embodiment, as shown in FIG. 2, the ceiling member 44 does not vibrate much at the lower end portion position of the hanging tree 20, so The TMD 30 is placed at the position. In other words, the TMD 30 is disposed between the lower end position of one hanging tree 20 and the lower end position of the other hanging tree 20 that are adjacent in plan view. Thereby, TMD30 can be arrange | positioned in the effective position for vibration reduction.

  In addition, this arrangement (arrangement of the TMD 30 between the lower end position of one suspension tree 20 adjacent to the other suspension tree 20 and the lower end position of the other suspension tree 20 in plan view) covers the entire area of the ceiling surface 28 in plan view. As a result, many TMDs 30 are disposed near the position of the vibration mode antinodes generated in the ceiling member 44 or near the position of the vibration mode antinodes, and the weight impact sound can be reduced more effectively. .

  In addition, the center between the lower end position of one suspension tree 20 and the lower end position of the other suspension tree 20 that are adjacent in plan view is often the position of the antinode of vibration in the primary mode. By arranging TMD 30 in the center between the lower end position of one adjacent hanging tree 20 and the lower end position of the other hanging tree 20, TMD 30 is positioned at a more effective position for vibration reduction with respect to the vibration of the primary mode. Can be arranged.

  Further, also on the outer periphery of the ceiling surface 28, the ceiling member 44 is provided at the fixing position of the ceiling member 44 (the position of the square member 42 provided on the outer periphery on the long side of the ceiling surface 28, or the outer periphery on the short side of the ceiling surface 28. Therefore, the TMD 30 is disposed at a plane position other than the fixed position and the lower end position of the hanging tree 20. That is, the TMD 30 is disposed at an effective position for reducing vibration with respect to the outer periphery of the ceiling surface 28 by disposing the TMD 30 between the fixed position and the lower end position of the hanging tree 20 in plan view. be able to.

  In addition, since the center between the fixed position in plan view and the lower end position of the suspension tree 20 is often the position of the antinode of the vibration in the primary mode, vibration reduction is achieved with respect to the vibration of the primary mode in the outer periphery of the ceiling surface 28. Therefore, the TMD 30 can be disposed at a more effective position.

  Further, since many weight members 16 are arranged on the ceiling member 44 by arranging the TMD 30 over the entire area of the ceiling surface 28 in a plan view, the mass ratio of the total mass of the weight member 16 to the total mass of the ceiling member 44 is growing. As a result, a large vibration reduction effect is obtained and the robustness of vibration reduction is increased.

  In the first embodiment, the TMD 30 is attached to the upper surface of the ceiling member 44 (ceiling board 14). However, the TMD 30 may be attached to the lower surface of the ceiling member 44. Further, as shown in FIG. 2, when the field edge 24 is present at the position where the TMD 30 is to be disposed, the TMD 30 may be attached with a slight shift, or the TMD 30 may be attached to the upper surface of the field edge 24 or the field edge receiver 22. Good.

  In the first embodiment, the center between the lower end position of one suspension tree 20 and the lower end position of the other suspension tree 20 that are adjacent in plan view, or the fixed position of the ceiling member 44 (of the ceiling surface 28). An example in which the TMD 30 is arranged at the center between the position of the square member 42 provided on the outer periphery of the long side or the position of the field edge 24 provided on the outer periphery of the short side of the ceiling surface 28) and the position of the lower end portion of the hanging tree 20. Although shown, TMD 30 is the middle of the lower end position of one suspension tree 20 and the lower end position of the other suspension tree 20 that are adjacent in plan view, or the fixed position of the ceiling member 44 (the long side of the ceiling surface 28). The position of the square member 42 provided on the outer periphery of the side or the position of the field edge 24 provided on the outer periphery of the short side of the ceiling surface 28) and the position of the lower end of the suspended tree 20 may be provided. That is, the TMD 30 may be disposed over the entire area of the ceiling surface 28 at a planar position other than the position of the lower end portion of the suspended tree 20 where the ceiling member 44 does not vibrate so much or the position where the ceiling member 44 is fixed.

  In the first embodiment, the mass m of the weight member 16 and the spring constant of the viscoelastic body 26 are selected so that the natural frequency of the TMD 30 is substantially equal to the center frequency of the 63 Hz band. However, the natural frequency of the TMD 30 is selected. May be completely equal to the center frequency of the 63 Hz band, or may be a value close to the center frequency of the 63 Hz band.

According to the principle of TMD, the frequency of vibration generated in the structure to be controlled for vibration (the ceiling member 44 in the example of FIG. 1) is ω ₁ , and the natural frequency of TMD (TMD 30 in the example of FIG. 1) is ω _2. The mass ratio indicating the ratio of the mass of TMD (the mass m of the weight member 16 in the example of FIG. 1) to the mass of the structure to be controlled for vibration (the mass M of the ceiling member 44 in the example of FIG. 1) is μ ( In the example shown in FIG. 1, m / M) and the frequency ratio obtained by dividing ω ₂ by ω ₁ is γ (= ω ₂ / ω ₁ ), and the optimal frequency ratio at which TMD effectively exhibits a vibration reduction effect is shown. γ _opt is 1 / (1 + μ). That is, the optimum frequency ratio γ _opt is a value that depends only on the mass ratio μ.
For example, when the mass ratio μ is 0.1, the optimum frequency ratio γ _opt is about 0.9 (= 1 / 1.1). That is, if the natural frequency ω ₂ of the TMD is made slightly smaller than the frequency ω ₁ of the vibration generated in the structure to be controlled for vibration, an effective vibration reducing effect of TMD can be obtained.

Therefore, it is preferable that the natural frequency of the TMD 30 adjusted by selecting the mass m of the weight member 16 and the spring constant of the viscoelastic body 26 is slightly smaller than the center frequency of the 63 Hz band, and the mass is at the center frequency of the 63 Hz band. A value obtained by multiplying the optimum frequency ratio γ _opt obtained from the ratio μ is more preferable.

  Next, a second embodiment of the present invention will be described.

  In the second embodiment, the arrangement of the TMD 30 of the first embodiment is changed. Therefore, in the description of the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and are appropriately omitted.

  In the ceiling structure 62 of the second embodiment, as shown in the plan view of FIG. 7 in which the ceiling structure 62 is viewed downward from the floor slab 12 side, the TMD 30 is uniformly arranged over the entire area of the ceiling surface 28 in plan view. ing. With respect to the ceiling surface 28, the TMDs 30 are arranged at a pitch of 454.5 mm in the horizontal direction (long side direction of the ceiling surface 28) and 500 mm in the vertical direction (short side direction of the ceiling surface 28). In addition, arrange | positioning TMD30 uniformly means arrange | positioning TMD30 by the fixed pitch, and arrange | positioning TMD30 so that the surface density of TMD30 may become fixed.

  If the TMD 30 is arranged so as to straddle the adjacent ceiling boards 14, the installation of the TMD 30 is troublesome. Therefore, the allocation of the ceiling boards 14 is different from that in FIG. 2 of the first embodiment so that the arrangement is not achieved. For convenience of explanation, a part of the field edge 24 and the field edge receiver 22 are omitted in FIG.

  Next, the operation and effect of the second embodiment of the present invention will be described.

The TMD 30 can effectively reduce vibration by being arranged at the position of the antinode of the vibration mode.
However, it is difficult to specify the position of the antinode of the vibration mode generated in the ceiling member 44 provided below the floor slab 12. Moreover, when specifying the position of the antinode of the vibration mode by vibration measurement, it takes several hours of measurement time for each room, so it is laborious to measure the vibration of all the rooms in an apartment house with many rooms. .

  On the other hand, in the ceiling structure 62 of the second embodiment, since the TMD 30 is uniformly arranged over the entire area of the ceiling surface 28 in plan view, the position of the antinode of the vibration mode generated in the ceiling member 44 or the vibration mode As a result, many TMDs 30 are arranged near the position of the belly, and the heavy floor impact sound can be effectively reduced.

  Further, since the arrangement of the TMD 30 is effective for various vibration modes, the members (the field edge 24, the field edge receiver 22) constituting the ceiling member 44 and the looseness of the joints such as the hanging tree 20 and the ceiling member This is particularly effective when it is difficult to specify the vibration mode properties of the ceiling member 44 (ceiling board 14) due to the construction error 44.

  In the second embodiment, the ceiling member 44 may be fixed to the floor slab 12 or the beam without using the hanging tree 20. In the ceiling structure 62, the TMD 30 is not arranged with respect to the position of the suspended tree 20. Therefore, for example, a small beam is bridged between structural members such as walls and beams, and the ceiling board 14 is fixed to the small beam. Even when the suspension member having a small rigidity is used, the position where the TMD 30 is disposed can be determined even when the lower end portion of the suspension member vibrates.

  Further, since many weight members 16 are arranged on the ceiling member 44 by arranging the TMD 30 over the entire area of the ceiling surface 28 in a plan view, the mass ratio of the total mass of the weight member 16 to the total mass of the ceiling member 44 is growing. As a result, a large vibration reduction effect is obtained and the robustness of vibration reduction is increased.

  The arrangement pattern of the TMD 30 is not limited to that shown in FIG. 7, and other arrangement patterns may be used as long as the TMD 30 is uniformly arranged over the entire ceiling surface 28 in a plan view.

  Next, a third embodiment of the present invention and its operation and effect will be described.

  In the third embodiment, the arrangement of the TMD 30 of the first embodiment is determined based on the result of actual measurement of the heavy floor impact sound. Therefore, in the description of the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and are appropriately omitted.

In the third embodiment, a plurality of acceleration sensors are arranged uniformly over the entire ceiling surface 28 in plan view. These acceleration sensors are installed on the lower surface of the ceiling member 44 (ceiling board 14).
Then, a heavy floor impact sound is generated on the upper surface 60 of the floor portion 36 by a method similar to the embodiment described later, and the vibration acceleration of the ceiling member 44 at this time is measured by an acceleration sensor installed on the ceiling member 44. Further, the TMD 30 is disposed at the position of the ceiling member 44 where the measured vibration acceleration is equal to or greater than a predetermined value.

  Therefore, by placing the TMD 30 at the position of the ceiling member 44 where the measured vibration acceleration is equal to or higher than a predetermined value, it is possible to reliably reduce the heavy floor impact sound of the vibration acceleration higher than the predetermined value generated in the ceiling member 44. .

  In addition, since the vibration mode can be accurately specified, the TMD 30 can be disposed only at the position of the ceiling member 44 where the vibration acceleration needs to be reduced, thereby reducing the number of TMDs 30 to be installed.

  The natural frequency of the TMD 30 may be substantially equal to the center frequency of the 63 Hz band as in the first and second embodiments, or may be substantially equal to the most problematic frequency based on the measurement result. Good. For example, you may make it substantially equal to the frequency with high frequency which shows the vibration acceleration more than predetermined value.

  Further, as described in the first and second embodiments, by arranging the TMD 30 over the entire area of the ceiling surface 28 in a plan view, the mass ratio increases, thereby obtaining a great vibration reduction effect and vibration reduction. Therefore, if the TMD 30 is installed in addition to the position of the ceiling member 44 where the measured vibration acceleration is equal to or greater than a predetermined value, a greater vibration reduction effect can be exerted on the wide band.

  Next, a fourth embodiment of the present invention and its operation and effect will be described.

  In the fourth embodiment, a wall TMD is provided on a wall surface material that forms a wall space connected to the ceiling space 48 of the ceiling structure 10 of the first embodiment. Therefore, in the description of the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and are appropriately omitted.

In the ceiling structure 64 of the fourth embodiment, as shown in FIG. 8, a wall space 66 that partitions the lower floor room R ₁ of the floor slab 12 is formed by wall surface materials 68 and 70. The wall space 66 is connected to a ceiling space 48 formed between the floor slab 12 and the ceiling surface 28. The attached weight member 74 via the viscoelastic member 72 to the surface of the wall member 68 facing the room R _1, wall TMD76 is constituted by the weight member 74 and the viscoelastic body 72.
Similar to the viscoelastic body 26 and the weight member 16 of the first embodiment, the viscoelastic body 72 is formed of a thermoplastic elastomer, and the weight member 74 is formed of an iron plate.

The heavy floor impact sound radiated to the ceiling space 48 formed between the floor slab 12 and the ceiling surface 28 is transmitted to the wall surface materials 68 and 70 through the wall space 66 connected to the ceiling space 48. Then, heavy floor impact sounds to the lower floor of the room R ₁ of the floor slab 12 from the wall material 68 is radiated, which can be a cause of comfort deteriorates.
On the other hand, in the ceiling structure 64 of the fourth embodiment, the wall TMD 76 suppresses the vibration of the wall surface material 68, thereby reducing the sound radiated from the wall surface material 68 to the lower floor room R _1. .

Note that the wall TMD 76 only needs to be installed on the surface of the wall surface material to be subjected to vibration reduction. That is, it may be installed in the wall space 66 side as shown in FIG. 8, may be installed in the room R ₁ side.

  The wall TMD 76 may be applied to the second and third embodiments. When the opening 78 above the wall surface material 70 is closed, more vibration energy flows from the ceiling space 48 to the wall space 66, so that the vibration of the wall surface material 68 increases. Therefore, the installation of the wall TMD 76 on the wall surface material 68 becomes more effective.

  Next, a fifth embodiment of the present invention and its operation and effect will be described.

  5th Embodiment shows an example of the construction method of the ceiling structure shown in 1st-4th embodiment. Therefore, in the description of the fifth embodiment, components having the same configurations as those of the first to fourth embodiments are denoted by the same reference numerals and are appropriately omitted.

5th Embodiment demonstrates the construction method of the ceiling structure of the three patterns shown to FIGS.
In the construction method for the ceiling structure shown in FIG. 9, first, as shown in FIG.
Next, as shown in FIG.9 (b), the ceiling board 14 to which TMD30 was attached is provided in the position 80 below the floor slab 12 (ceiling surface material installation process).
After that, the work shown in FIGS. 9A and 9B is repeated to construct the ceiling structure.

  Therefore, since the vibration damping device installation process for attaching the TMD 30 to the ceiling board 14 is performed before the ceiling surface material installation process in which the ceiling board 14 is provided below the floor slab 12 to form the ceiling surface 28, the TMD 30 is attached to the ceiling board 14. The TMD 30 can be attached at a place where it can be easily attached.

  In the construction method of the ceiling structure shown in FIG. 10, first, as shown in FIG. 10A, the ceiling board 14 to which the TMD 30 is attached is provided below the floor slab 12 to form the ceiling surface (ceiling surface material installation step). . At this time, since the ceiling board 14 adjacent to the ceiling board 14 to which the TMD 30 is attached is not yet provided below the floor slab 12, an opening 82 is formed at a position where the ceiling board 14 is installed.

Next, the TMD 30 is inserted from the opening 82 and attached to the upper surface of the ceiling board 14 (vibration control device installation step).
Next, as shown in FIG. 10B, the ceiling board 14 is installed in the opening 82.
After that, the work shown in FIGS. 10A and 10B is repeated to construct the ceiling structure.

  Therefore, before the vibration damping device installation process for attaching the TMD 30 to the ceiling board 14, the ceiling board material installation process in which the ceiling board 14 is provided below the floor slab 12 to form the ceiling surface 28 is performed. When the TMD 30 is attached to the ceiling board 14 by renovation work after being provided below the slab 12, the TMD 30 can be attached to the ceiling board 14 without removing the ceiling board 14 to which the TMD 30 is attached.

  That is, after removing only the ceiling board 14 adjacent to the ceiling board 14 to which the TMD 30 is attached, the TMD 30 may be attached to the ceiling board 14 that has not been removed, and the removed ceiling board 14 may be restored. Then, by repeating this work, the TMD 30 can be installed with a minimum construction range.

  The opening for inserting the TMD 30 may be formed with a saw or the like so that the TMD 30 or a hand can be inserted without removing the entire ceiling board 14. Such a method is effective when the partition board is installed under the ceiling board 14 and the ceiling board 14 cannot be removed.

In the ceiling structure construction method shown in FIG. 11, first, as shown in FIG. 11A, the ceiling board 14 is provided below the floor slab 12 to form a ceiling surface (ceiling surface material installation step).
Next, as shown in FIG.11 (b), TMD30 is attached to the lower surface of the ceiling board 14 from the downward direction of the ceiling board 14 (vibration control apparatus installation process).
Therefore, the same effect as in the case of FIG. 10 can be obtained. Further, it is not necessary to remove the ceiling board 14 in the renovation work.

  In addition, in the 1st-5th embodiment, although the ceiling board 14 as a ceiling surface material was used as the gypsum board, it should just be a surface material used for a general suspended ceiling, and a plywood may be used. The dimensions and assignment of the ceiling board 14 and the arrangement of the field edge 24 and field edge receiver 22 that support the ceiling board 14 may be determined as appropriate. If the TMD 30 is arranged so as to straddle the adjacent ceiling boards 14, the mounting of the TMD 30 is troublesome. Therefore, it is preferable to allocate the ceiling boards 14 so that such arrangement is not caused.

In the first to fifth embodiments, the viscoelastic bodies 26 and 72 are thermoplastic elastomers. However, the viscoelastic bodies 26 and 72 may be any material that can obtain predetermined spring constants and damping constants. Chloroprene Anti-vibration rubber such as rubber, polymer gel such as silicone gel, or foaming material such as polyurethane may be used.
In the case of a material with low damping, the robustness of vibration reduction when the natural frequency of TMD 30 and TMD 76 for wall and the frequency of vibration generated in ceiling member 44 and wall surface material 68 deviate becomes low. It is preferable to use a thermoplastic elastomer which is an elastomer of the above and a high damping rubber having the same performance.

  In the first to fifth embodiments, the weight members 16 and 74 are iron plates. However, the weight members 16 and 74 only have to have a predetermined mass, and the shape, dimensions, and the like are required for vibration reduction. What is necessary is just to determine suitably according to performance.

  Moreover, in the 1st-5th embodiment, although the ceiling member 44 was comprised by the ceiling board 14, the field edge 24, and the field edge receiver 22, when the 1st-5th embodiment is applied to a system ceiling. Constitutes a ceiling member by a ceiling board and a support beam (T-bar) on which the ceiling board is placed. Moreover, in the case of a ceiling structure that does not require a field edge by directly fixing a ceiling board having sufficient rigidity to the lower end portion of the suspension member, the ceiling member is constituted only by the ceiling board.

  Further, in the first to fifth embodiments, the bar-shaped member is the hanging tree 20, but the ceiling member 44 only needs to be hung from the floor slab or the beam. For example, when the first to fifth embodiments are applied to the system ceiling, the suspension bolt that is suspended from the floor slab and supports the support beam (T-bar) on which the ceiling board is placed is a bar-shaped member. Become. Further, the arrangement of the rod-shaped members with respect to the ceiling surface 28 may be determined as appropriate according to the weight of the ceiling member 44 and the like.

  In the first to fifth embodiments, the ceiling member 44 is suspended by the suspension tree 20 provided on the floor slab 12. However, the ceiling member 44 is suspended on the beam 84 as shown in FIG. It may be suspended from the tree 20 or may be fixed to the beam 84 via a square or the like or directly.

  In the first to fifth embodiments, the outer periphery of the ceiling member 44 is fixed to the wall 40. However, the outer periphery of the ceiling member 44 may be fixed to a beam 86 as shown in FIG. 12 may be fixed. Moreover, you may make it the outer periphery of the ceiling member 44 suspend from the floor slab 12 or a beam with a rod-shaped member.

In the first to fifth embodiments, the mass m of the weight member 16 and the spring constant of the viscoelastic body 26 are selected so that the natural frequency of the TMD 30 is substantially equal to the center frequency of the 63 Hz band. The natural frequency may be approximately equal to the center frequency of the frequency band where the vibration reduction effect is desired.
For example, the predetermined frequency band may be a 31.5 Hz band, a 125 Hz band, a 250 Hz band, or a 500 Hz band. As a result, the heavy floor impact sound at the center frequency of these predetermined frequency bands can be reduced, and the mass ratio μ is increased to increase the robustness of vibration reduction of the TMD 30, and the predetermined frequency near the center frequency is increased. It is possible to reduce the heavy floor impact sound of the band.

  In addition, the TMDs 30 of the plurality of TMDs 30 are made different from each other so that the TMDs 30 are arranged close to one place, the mass of the weight member 16 of one TMD 30 is increased, or a plurality of TMDs 30 having the same natural frequency are arranged. It may be arranged close to the location to increase the overall mass. In this way, since the robustness of vibration reduction is increased, the vibration reduction effect can be exhibited for both adjacent frequency bands.

  Moreover, the 1st-5th embodiment acquires the effect similar to the effect with respect to the heavy floor impact sound of the 1st-5th embodiment also with respect to the lightweight floor impact sound generated above the floor slab 12. Can do. Since the light floor impact sound can reduce vibrations relatively easily with a flooring finishing material or the like, the first to fifth effects that are superior to the heavy floor impact sound than the lightweight floor impact sound. This embodiment is a technique effective as a vibration reduction measure for floor impact sound.

  Moreover, the ceiling structure shown in the first to fifth embodiments may be applied to all rooms in the building or may be applied to some rooms in the building. As a result, it is possible to construct a building having a ceiling structure that reduces heavy floor impact sound by simple construction from a room on the lower floor.

  The first to fifth embodiments of the present invention have been described above, but the present invention is not limited to such embodiments, and the first to fifth embodiments may be used in combination. Needless to say, the present invention can be implemented in various modes without departing from the gist of the present invention.

(Example)
In order to confirm the vibration reducing effect on the heavy floor impact sound of the ceiling structure 10 shown in the first embodiment, the heavy floor impact sound was measured by the actual ceiling structure 10.
The heavy floor impact sound is measured by the Architectural Institute of Japan recommended measurement standard "Measurement method of floor impact sound level at the building site" or JIS-A-1418-2: 2000 "Measurement of floor impact sound insulation performance of buildings". In accordance with “Method—Part 2: Method Using Standard Weight Impact Source”, a heavy floor impact sound was measured using a bang machine (FIG. 15) and a rubber ball (FIG. 16).

As shown in the plan view of FIG. 14 (a), the diagonals of intersection of the upper surface 60 of the floor portion 36 located above the ceiling member 44 and vibration position S _1, a pressurizing four corners of and the upper surface 60 diagonally the bisecting positions vibration position connecting the _{S 1} line, and the position _{S 2, S 3, S 4} , S 5 excitation respectively. Further, as shown in the plan view of FIG. 14B and the front view of FIG. 14C, the lower floor located immediately below the excitation positions S ₁ , S ₂ , S ₃ , S ₄ , S ₅ Receiving microphones P ₁ , P ₂ , P ₃ , P ₄ , and P ₅ that receive heavy floor impact sound are arranged on the floor slab 88. In FIG. 14C, the support leg 38, the square member 18, the hanging tree 20, the field edge receiver 22, the field edge 24, and the like are omitted.

Then, by measuring the floor impact sound level (dB) received by the receiving microphones P _{1 to} P ₅ when the vibration positions S _{1 to} S ₅ are vibrated with a bang machine or a rubber ball, the heavy floor impact is measured. The sound was measured.

The heights of the receiving microphones P ₁ , P ₂ , P ₃ , P ₄ , and P ₅ were 120 cm, 180 cm, 90 cm, 60 cm, and 150 cm, respectively. Note that the floor impact sound level measurement data is obtained by correcting the background impact sound level measured by the _five receiving microphones P _{1 to} P ₅ with respect to _one excitation position S _{1 to} S ₅ and correcting the dark noise. A value obtained by power averaging the noise corrected values was obtained for each vibration position, and a value obtained by arithmetically averaging the power average values of the five vibration positions was used as a measurement result of the floor impact sound level.

  FIG. 15 is a graph showing the measurement result of the floor impact sound level with respect to the octave band center frequency when the heavy floor impact sound is generated by the bang machine. The value 90 is a measurement result when the TMD 30 is not installed on the ceiling member 44, and the value 92 is a measurement result when the TMD 30 is installed as shown in FIG.

  The floor impact sound level at 63 Hz is high for both values 90 and 92, and the sound insulation grade is determined at this frequency. The sound insulation rating of value 90 is LH70, and the sound insulation rating of value 92 is LH60, so that the comfort level is improved by two ranks.

Further, since the floor impact sound level at 63 Hz of the value 90 is 90.4 dB and the floor impact sound level at 63 Hz of the value 92 is 85.0 dB, the floor impact sound level can be obtained by installing the TMD 30 on the ceiling member 44. The level has dropped by 5.4 dB.
From these results, it can be seen that a vibration reducing effect can be obtained with respect to the heavy floor impact sound by the bang machine.

  FIG. 16 is a graph showing the measurement result of the floor impact sound level with respect to the octave band center frequency when the heavy floor impact sound is generated by the rubber ball. The value 94 is a measurement result when the TMD 30 is not installed on the ceiling member 44, and the value 96 is a measurement result when the TMD 30 is installed as shown in FIG.

  The floor impact sound level at 63 Hz is high for both values 94 and 96, and the sound insulation grade is determined at this frequency. The sound insulation rating of value 94 is LH60, and the sound insulation rating of value 96 is LH50, so the comfort is improved by 2 ranks.

Further, since the floor impact sound level at 63 Hz of the value 94 is 81.2 dB and the floor impact sound level at 63 Hz of the value 96 is 75.0 dB, the floor impact sound level is obtained by installing the TMD 30 on the ceiling member 44. The level has decreased by 6.2 dB.
From these results, it can be seen that a vibration reduction effect can be obtained with respect to the heavy floor impact sound caused by the rubber ball.

The 17-19, is shown the value of the acceleration spectrum (vertical axis) with respect to frequency (horizontal axis) when caused the heavy floor impact sound by vibrating the position S ₁ in Bang machine shown in FIG. 14 Yes.

  As shown in FIG. 20, acceleration sensors 98 are respectively provided on the lower surface (ceiling surface 28) of the ceiling board 14 immediately below the suspension tree 20 shown in FIG. 2 of the first embodiment, directly below the TMD 30, or immediately below the TMD 30. The acceleration sensor 98 was installed and the acceleration spectrum was measured.

That in plan view, and beneath the hanging trees _20, in a _{TMD30A 1 ~30A 13, 30B 1 ~30B} 13, 30C 1 ~30C 13, 30D 1 ~30D 13, 30E 1 ~30E 13 around beneath or below the, the acceleration sensor _{98A 1 ~98A 13, 98B 1 ~98B} 13, 98C 1 ~98C 13, 98D 1 ~98D 13, 98E 1 ~98E 13 is disposed.

The acceleration sensor _{98A 1 ~98A 13, 98B 1 ~98B} 13, 98C 1 ~98C 13, 98D 1 ~98D 13, 98E 1 ~98E 13 is laterally pitch 454.5Mm (longitudinal direction of the ceiling surface 28) In addition, they are arranged at a pitch of 500 mm in the vertical direction (the short side direction of the ceiling surface 28).

  Moreover, the value 100 shown in FIGS. 17-19 is a measurement result in the state which has not installed TMD30 in the ceiling member 44, and the value 102 is the measurement in the state in which TMD30 was installed as shown in FIG. It is a result.

Value _{100A 1 ~100A 13, 100B 1 ~100B} 13, 100C 1 ~100C 13, 100D 1 ~100D 13, 100E 1 ~100E 13 includes an acceleration sensor _{98A 1 ~98A 13, 98B 1 ~98B} 13, 98C 1 ~98C ₁₃ , 98D _{1 to} 98D ₁₃ , and 98E _{1 to} 98E ₁₃ .

Also, the values 102A _{1 to} 102A ₁₃ , 102B _{1 to} 102B ₁₃ , 102C _{1 to} 102C ₁₃ , 102D _{1 to} 102D ₁₃ , 102E _{1 to} 102E ₁₃ are acceleration sensors 98A _{1 to} 98A ₁₃ , 98B _{1 to} 98B ₁₃ , 98C ₁ ~98C _13, a respective value of _{98D 1 ~98D 13, 98E 1 ~98E} 13.

  As shown in FIGS. 17 to 19, the value 102 that is the measurement result with the TMD 30 installed is substantially smaller than the value 100 that is the measurement result with the TMD 30 not installed on the ceiling member 44. From this, it can be seen that a vibration reducing effect can be obtained with respect to the heavy floor impact sound by the bang machine.

The value _{100B 2, 100B 4, 100B 6} , 100B 8, 100B 10, 100B 12, 100D 2, 100D 4, 100D 6, 100D 8, 100D 10, 100D 12 in FIG. 17 to 19, none of the small value From this, it can be seen that the ceiling member 44 at the lower end portion of the hanging tree 20 does not vibrate very much.

Moreover, not vibrating around the position _{S 1} is necessarily large vibration (e.g., the value 100C _8, 100D ₇ in FIG. 18), also not always reflect poorly vibration position away from the excitation position _{S 1} ( For example, the value 100D ₃ in FIG. 17 and the value 100C _{10 in} FIG. 19). This shows that it is difficult to specify the position of the vibration mode belly on the suspended ceiling.

In the arrangement of the TMD 30 shown in FIG. 2, 53 weight members 16 each having 1 kg are arranged on the ceiling surface 28 of about 20 m ² . That is, the effect of reducing the heavy floor impact sound is obtained with a weight of about 2.6 kg / m ² .
Since the sound insulation mat such as heavy rubber as shown in the cited document 1 is usually a material having a specific gravity of 2 to 3 and a thickness of 4 mm or more, in this case, it becomes about 8 to 12 kg / m ² . It turns out that this invention is the technique excellent in the construction property using a lightweight damping device.

It is a front view which shows the ceiling structure which concerns on the 1st Embodiment of this invention. It is a top view which shows the ceiling structure which concerns on the 1st Embodiment of this invention. It is a front view which shows the outer peripheral part of the ceiling structure which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the vibration analysis model of the ceiling structure which concerns on the 1st Embodiment of this invention. It is a diagram explaining the vibration reduction characteristic of the ceiling structure which concerns on the 1st Embodiment of this invention. It is a diagram explaining the robustness of the vibration reduction of the ceiling structure which concerns on the 1st Embodiment of this invention. It is a top view which shows the ceiling structure which concerns on the 2nd Embodiment of this invention. It is a front view which shows the ceiling structure which concerns on the 4th Embodiment of this invention. It is explanatory drawing which shows the construction method of the ceiling structure which concerns on the 5th Embodiment of this invention. It is explanatory drawing which shows the construction method of the ceiling structure which concerns on the 5th Embodiment of this invention. It is explanatory drawing which shows the construction method of the ceiling structure which concerns on the 5th Embodiment of this invention. It is a front view which shows the modification of the ceiling structure which concerns on embodiment of this invention. It is a front view which shows the modification of the ceiling structure which concerns on embodiment of this invention. It is explanatory drawing which shows the measuring method of the heavy floor impact sound which concerns on the Example of this invention. It is a diagram which shows the measurement result of the heavy floor impact sound based on the Example of this invention. It is a diagram which shows the measurement result of the heavy floor impact sound based on the Example of this invention. It is a diagram which shows the measurement result of the vibration acceleration which concerns on the Example of this invention. It is a diagram which shows the measurement result of the vibration acceleration which concerns on the Example of this invention. It is a diagram which shows the measurement result of the vibration acceleration which concerns on the Example of this invention. It is a top view which shows the measuring method of the vibration acceleration which concerns on the Example of this invention. It is a front view which shows the conventional dry type double floor. It is a perspective view which shows the conventional lower floor building unit.

Explanation of symbols

10, 62, 64 Ceiling structure 12 Floor slab 14 Ceiling board (ceiling surface material)
16, 74 Weight member 20 Suspended tree (bar-shaped member)
26, 72 Viscoelastic body 28 Ceiling 30 TMD (vibration control device)
44 Ceiling member 48 Ceiling space 66 Wall space 68 Wall material 84, 86 Beam R ₁ room

Claims (11)

A ceiling member provided below the floor slab to form a ceiling surface;
A damping device composed of a weight member attached to the upper surface or the lower surface of the ceiling member via a viscoelastic body and the viscoelastic body;
The ceiling structure characterized by having.   The ceiling member is suspended from a plurality of rod-like members provided on the floor slab or beam, and the vibration control device is one of the rod-like members that covers the entire area of the ceiling surface in plan view and is adjacent in plan view. The ceiling structure according to claim 1, wherein the ceiling structure is arranged between a lower end position of the member and a lower end position of the other rod-shaped member.   The said damping device is arrange | positioned in the center of the lower end part position of one said rod-shaped member adjacent in planar view, and the lower end part position of the other said rod-shaped member, It is characterized by the above-mentioned. Ceiling structure.   The ceiling structure according to claim 1, wherein the vibration damping device is uniformly arranged over the entire area of the ceiling surface in a plan view.   A heavy floor impact sound is generated above the floor slab to measure the vibration acceleration of the ceiling member, and the vibration damping device is disposed at the position of the ceiling member where the vibration acceleration is a predetermined value or more. The ceiling structure according to claim 1.   The mass of the weight member and the spring constant of the viscoelastic body are selected so that the center frequency of a predetermined frequency band and the natural frequency of the vibration damping device are substantially equal. The ceiling structure according to any one of 5.   The ceiling structure according to claim 6, wherein the predetermined frequency band is a 63 Hz band or a 125 Hz band. A wall surface material for partitioning a lower floor room of the floor slab to form a wall space connected to a ceiling space formed between the floor slab and the ceiling surface;
The ceiling structure according to any one of claims 1 to 7, wherein a weight member is attached to a surface of the wall material via a viscoelastic body. In the construction method of the ceiling structure which constructs the ceiling structure according to any one of claims 1 to 8,
A vibration damping device installation step of attaching the vibration damping device to a ceiling surface material constituting the ceiling member;
A ceiling surface material installation step of forming the ceiling surface material below the floor slab after the vibration damping device installation step;
A method for constructing a ceiling structure characterized by comprising: In the construction method of the ceiling structure which constructs the ceiling structure according to any one of claims 1 to 8,
A ceiling surface material installation step of forming a ceiling surface by providing a ceiling surface material constituting the ceiling member below the floor slab;
A vibration damping device installation step of attaching the vibration damping device to the ceiling surface material after the ceiling surface material installation step;
A method for constructing a ceiling structure characterized by comprising:   A building having the ceiling structure according to claim 1.

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