JP7503434B2 - Anti-vibration floor structure - Google Patents

Description

The present invention relates to a vibration-proof floor structure.

Patent Document 1 discloses technology related to vibration-isolated floor structures. In this prior art, the vibration-isolated floor structure is composed of a floating floor supported by air springs installed on the base plate, and multiple piles installed on the ground. In addition, a group of piles is provided that supports the base plate, and the area below the floating floor has higher vertical stiffness than the other areas.

Patent Document 2 discloses technology relating to a vibration-isolated floor structure. In this prior art, the vibration-isolated floor structure includes a spring member with its spring axis oriented vertically inside a recess in a structure, and a floating floor that is supported by connecting the upper ends of the spring member and is provided in the recess. In addition, the floating floor includes a displacement control device for restricting horizontal displacement without impeding vertical displacement relative to the structure.

Patent document 3 discloses technology related to an ultrasonic vibrator support structure. In this prior art, the ultrasonic vibrator support structure includes an ultrasonic vibrator, a vibration transmitter coaxially connected to the end face of the ultrasonic vibrator, two flanges acting as pistons provided at a predetermined distance on the outer periphery of the vibration transmitter, a cylinder that houses the flanges, and a means for supplying pressurized fluid to the spaces formed between each flange and each end of the cylinder.

Patent Document 4 discloses technology relating to an anti-vibration floor structure that can reduce vibrations propagating from within a building (structure) that has a vibration source to the building itself or its surroundings, and vibrations propagating from a vibration source in the vicinity of the building to within the building. In this prior art, the anti-vibration floor structure has a floor slab that is placed within a structure built on the ground and is separated from the structure, a support member that supports the floor slab on a support base that is below the ground while floating it above the ground, and a vibration isolating means that isolates vibrations transmitted from the support member to the ground or from the ground to the support member.

JP 2019-090211 A JP 2019-178555 A Japanese Patent Application Laid-Open No. 63-193699 JP 2007-107208 A

In concert halls and other venues, the vibrations caused by audience members jumping up and down can be a problem as they spread to surrounding buildings. Prior art has reduced the vibrations that spread to surrounding buildings by using vibration-isolating floors supported by vibration-isolating devices.

However, when a person on a vibration-isolated floor performs an action that generates a small vibration force, such as walking, the floor shakes, creating vibrations that the person standing on the floor finds unpleasant, or in other words, a "fluffy" feeling.

In view of the above, the present invention aims to suppress the vibration of the vibration-isolating floor when the vibration force is small, such as walking, and to demonstrate the vibration-isolating performance of the vibration-isolating floor when the vibration force is large, such as vertical sliding.

The first aspect is a vibration-isolation floor structure that includes a vibration-isolation floor supported by a vibration-isolation device installed on a structure, and a constraint mechanism that is provided between the structure and the vibration-isolation floor and that constrains the horizontal movement of the vibration-isolation floor relative to the structure and causes the vibration-isolation device to exhibit vibration isolation performance when friction that constrains the vertical movement is broken.

In the first embodiment of the vibration-isolated floor structure, the restraint mechanism restrains vertical movement by friction, so shaking of the vibration-isolated floor is suppressed when a person on the vibration-isolated floor performs an action with a small vibration force, such as walking. On the other hand, when a person on the vibration-isolated floor performs an action with a large vibration force, such as vertical sliding, the friction that restrains the vertical movement of the restraint mechanism breaks, and the vibration-isolation device demonstrates its vibration-isolation performance. This reduces the vibrations that propagate to surrounding buildings.

In the second aspect, the restraint mechanism is a vibration-proof floor structure according to the first aspect, which includes a first friction plate provided vertically on one of the structure or the vibration-proof floor, a first housing protruding horizontally from the other of the structure or the vibration-proof floor, a second housing slidably provided on the first housing and joined to the first housing with a second friction plate at the tip end in surface contact with the first friction plate, and a filler that fills the first housing and the second housing, hardens, and maintains the surface contact state between the first friction plate and the second friction plate.

In the second embodiment of the vibration-proof floor structure, the second housing is joined to the first housing with the second friction plate at the tip in surface contact with the first friction plate, and a filler is filled into the first housing and the second housing and hardened, thereby maintaining the surface contact state between the first and second friction plates. Therefore, while the restraining mechanism restrains horizontal movement of the vibration-proof floor relative to the structure, the friction between the surface-contacting first and second friction plates can restrain vertical movement.

A third aspect is a vibration-isolated floor structure described in the first or second aspect, in which the restraint mechanism is configured so that _T2 > Q ≧ T1 holds, where the upper limit value at which the friction breaks is the vertical force of the vibration-isolated floor _{, Q} (N), the excitation force generated by a person walking on the vibration-isolated floor, and _T2 ( _N ), the excitation force generated by a person jumping and landing on the vibration-isolated floor.

In the vibration-isolated floor structure of the third embodiment, it is set so that _T2 >Q> _T1 holds true. Therefore, when a person on the vibration-isolated floor walks on it, the vibration of the vibration-isolated floor is suppressed, and when a person on the vibration-isolated floor jumps on it, the vibration-isolation performance of the vibration isolation device is exerted.

According to the present invention, the vibration of the vibration-proof floor can be suppressed during movements with small vibration forces, such as walking, and the vibration-proof performance of the vibration-proof floor can be exhibited during movements with large vibration forces, such as vertical sliding.

FIG. 1 is a schematic diagram showing a structure of a building to which a vibration-isolating floor structure is applied. FIG. 2 is a cross-sectional view of a main part of the building of FIG. 1 . 2 is a front view, partially in cross section, of the vibration isolation device of FIG. 1 . 1A is a front view of the restraint device, and FIG. 1B is a top view of the restraint device. 1 is a graph showing the relationship between excitation force and friction force. 6A is a cross-sectional view showing a schematic horizontal cross-section of the mockup (B) taken along 6B-6B, and FIG. 6B is a cross-sectional view showing a schematic vertical cross-section of the mockup (A) taken along 6A-6A. 13 is a graph showing the acceleration of the measurement results of a mockup. 1 is a graph showing the vibration reduction effect of a vibration-proof floor structure.

<Embodiment>
An embodiment of the vibration-isolating floor structure according to the present invention will now be described.

[composition]
First, the configuration of the vibration-isolating floor structure of this embodiment will be described.

As shown in FIG. 1, the building 10 is equipped with a vibration-isolating floor 70 of the vibration-isolating floor structure 102 of this embodiment. In addition, buildings 300 and 302 are constructed around the building 10.

The building 10 is constructed on the ground 20 and is supported by a number of piles 59 installed in the ground 20. In this embodiment, the building 10 is a concert hall. Inside the building 10, an arena 12 and stepped seating 15 are provided. A part of the slab 30 that constitutes the arena 12 is an anti-vibration floor 70.

As shown in Figures 1 and 2, the vibration-isolating floor 70 is supported by a number of vibration-isolating devices 50 installed on the base 36 that constitutes the structural body 32 of the building 10. In this embodiment, the vibration-isolating devices 50 are installed on a stand 38 provided on the base 36.

As shown in FIG. 3, the vibration isolation device 50 of this embodiment is configured to include a coil spring 52 and a damper 54, but is not limited to this. Any type of device may be used. For example, the vibration isolation device 50 may be configured as an air spring.

As shown in FIG. 2, the gap between the side wall 30B of the outer periphery 30A of the slab 30 constituting the structure 32 and the side wall 70B of the outer periphery 70A of the vibration-proof floor 70 is covered by a movable plate 82 constituting the expansion joint 80. A restraining mechanism 100 is provided between the side wall 30B of the outer periphery 30A of the slab 30 and the side wall 70B of the outer periphery 70A of the vibration-proof floor 70.

Although not shown in the figure, the vibration isolation floor 70 and the side wall 30B of the slab 30 are rectangular in plan view, and multiple restraint mechanisms 100 are provided at locations corresponding to each side of the rectangle.

With this configuration, the vibration isolation floor 70 shown in FIG. 1 is restricted from moving in the horizontal direction, but is restricted from moving in the vertical direction until friction is released, at which point it becomes movable. The meaning of "releasing friction" will be explained later.

The vertical vibration of the vibration-isolating floor 70 is damped by the damping function of the vibration-isolating device 50. In this embodiment, the mass of the vibration-isolating floor 70 is smaller than the mass of the base plate 36 that constitutes the structure 32, but this is not limited to this. Also, in this embodiment, the natural frequency of the vibration-isolating floor 70 is set to 1 Hz or less, but this is not limited to this.

(Restraint Mechanism)
Next, the restraint mechanism 100 will be described.

As shown in Fig. 4(A) and Fig. 4(B), the restraint mechanism 100 is configured to include a housing 150 having a second friction plate 162, a filler J (see Fig. 4(B)) filled in the housing 150, and a first friction plate 110. In this embodiment, the filler J is non-shrink mortar.

The driving plate 112 is fixed to the side wall 70B of the vibration-isolating floor 70 by studs 114 embedded in the outer periphery 70A of the vibration-isolating floor 70. The first friction plate 110 in this embodiment is arranged with its plate surface along the vertical direction and is joined to the driving plate 112. In this embodiment, the first friction plate 110 has a structure in which polytetrafluoroethylene (PTFE) and a metal plate are firmly joined together, and is joined to the driving plate 112 so that the polytetrafluoroethylene (PTFE) side, which is a low-friction material, is exposed.

The studs 114 and anchor bolts 116 (described later) are shown in solid lines for ease of understanding. In addition, in FIG. 4(B), the filler J is hatched for ease of understanding.

Anchor bolts 116 are embedded in the outer periphery 30A of the slab 30, and a driving plate 113 is fixed to the side wall 30B. The housing 150 of this embodiment is bolted to the anchor bolts 116 and fixed to the side wall 30B. The housing 150 is made of steel, has a box shape that is open at the top, and is composed of a first housing 152 and a second housing 160.

The second housing 160 is slightly larger than the first housing 152 and can slide horizontally relative to the first housing 152. The end of the first housing 152 on the slab 30 side is composed of a wide joint plate 154, which is bolted to the anchor bolts 116 embedded in the outer periphery 30A of the slab 30 described above. The joint plate 154 abuts against the driving plate 113. The side wall of the tip of the second housing 160 on the vibration-proof floor 70 side is composed of a second friction plate 162 that is aligned in the vertical direction.

The joining plate 154 of the first housing 152 is provided with a stud 156 that protrudes toward the second housing 160, and the second friction plate 162 of the second housing 160 is provided with a stud 166 that protrudes toward the first housing 152. These studs 156, 166 integrate the filler J and the housing 150.

The joining of the first housing 152 and the second housing 160 of the housing 150 constituting the restraint mechanism 100 and the filling of the filler J are carried out after the vibration-isolating floor 70 and the slab 30 have been constructed, i.e., after the positional relationship between the vibration-isolating floor 70 and the outer periphery 70A of the slab 30 has been determined.

Specifically, the second housing 160 is slid so that the second friction plate 162 at the tip is in surface contact with the first friction plate 110, and the two are then welded together. Note that reference numeral 158 in the figure indicates the welded portion. Then, the filler J is filled into the housing 150 and allowed to harden.

The restraint mechanism 100, with its structure and construction method, maintains the first friction plate 110 and the second friction plate 162 in surface contact with no gaps. This restrains the vibration-proof floor 70 from moving in the horizontal direction.

On the other hand, the vertical movement of the vibration isolation floor 70 is restricted by friction caused by surface contact between the first friction plate 110, which is made of PTFE, a low-friction material, and the second friction plate 162, which is made of steel. However, when the excitation force acting in the vertical direction of the vibration isolation floor 70 increases, the friction is broken and the vibration isolation device 50 exerts its vibration isolation performance.

From another perspective, when the vertical excitation force acting on the vibration isolation floor 70 is small, the vibration isolation floor 70 is restrained by the static friction force acting between the first friction plate 110 and the second friction plate 162. However, when the vibration excitation force acting on the vibration isolation floor 70 is large, the static friction force acting between the first friction plate 110 and the second friction plate 162 becomes a kinetic friction force, and the vibration isolation floor 70 moves in the vertical direction. At this time, by reducing the coefficient of friction acting between the first friction plate 110 and the second friction plate 162, the kinetic friction force is set small, and the vibration isolation device 50 can demonstrate its vibration isolation performance.

In Fig. 4, the horizontal axis represents the excitation force acting on the vibration-isolating floor 70, and the vertical axis represents the friction force F acting between the first friction plate 110 and the second friction plate 162. Line S represents the static friction force, and line D represents the kinetic friction force. Furthermore, _F0 represents the maximum static friction force, and friction force _F2 represents the kinetic friction force. The excitation force that results in the maximum friction force _F0 is _T0 , and when the excitation force exceeds _T0 , static friction changes to kinetic friction.

When the friction coefficient between the first friction plate 110 and the second friction plate 162 is μ and the normal force is N, the friction force F is expressed as follows:
F = μ × N
It becomes.

The normal force N of the restraining mechanisms 100 installed at multiple locations can be controlled by standardizing the fixing method of the restraining mechanisms 100. For example, in this embodiment, a jack or the like is installed between the side wall 70B of the outer periphery 70A of the vibration-isolating floor 70 and the side wall 30B of the outer periphery 30A of the slab 30, and while a predetermined force is applied in the direction in which they move apart, the restraining mechanism 100 is welded to the first housing 152 and the second housing 160, and the filler J is filled and hardened, and then the jack is removed, thereby controlling the normal force N.

In this embodiment, the excitation force _T1 when a predetermined number of people walk on the vibration-isolated floor 70 is set to be equal to or less than the excitation force _T0 that results in the maximum friction force _F0 . Furthermore, the excitation force _T2 when a predetermined number of people jump and land on the vibration-isolated floor 70 is set to be greater than the excitation force _T0 that results in the maximum friction force _F0 .

That is,
_T2 > _T0 ≧ _T1
The relationship is set as follows:

(Calculation method of T2, T0 and T1)
Next, a method for calculating T ₂ , T ₀ , and T ₁ will be described. Note that this calculation method is an example and is not limited to this.

The excitation force T ₀ that results in the maximum friction force F ₀ is calculated as the vertical load Q of the vibration isolation floor 70 .
In addition, the predetermined number of people who walk and jump and land on the vibration-isolating floor 70 at the same time is M (people),
The average weight of a person walking on the vibration-isolating floor 70 is K (kg),
Let α ₁ be the standardized value of the excitation force when a person of average weight K walks alone on the vibration-isolating floor 70 at a pitch of f ₁ (Hz),
The standardized value of the excitation force when a person of average weight K jumps and lands on the vibration-isolating floor 70 at a pitch of f ₂ (Hz) is defined as α ₂ ,
Then,
_T1 = √M × (K × 9.8) × _α1
T2 = √M × (K × 9.8) × _α2
The calculation is as follows.

In other words,
_T2 > _T0 ≧ _T1
teeth,
√M×(K×9.8)× _α2 ＞Q≧√M×(K×9.8)× _α1
It is calculated as follows.
In the above notation, in "√M", M is not exactly contained within √ (the root symbol), but in this specification, M is considered to be contained within √. Also, when other symbols or numbers are written after √, they are considered to be contained within √.

Here, the walking and jumping and landing of multiple people is random, so the excitation force is not simply multiplied by a given number of people. When M people are walking, a method is known in which the total weight is evaluated as "√M x average weight of pedestrians" based on the idea of energy summation. Therefore, in the above, it is not simply multiplied by M, but by √M.

In addition, f ₁ , f ₂ α ₁ and α ₂ were appropriately set and used from the following values described in "Design Materials Utilizing the Building Load Guidelines 1 ISBN978-4-8189-0632-7", but are not limited to these.

_f1 : 1.6Hz to 2.3Hz
_f2 : 2.0Hz to 3.0Hz
_α1 : 0.38 to 0.50
_α2 : 1.07 to 1.90

In this embodiment, the predetermined number of people (walking and jumping) M is set to 50% of the maximum number of people that can be accommodated on the vibration-isolating floor 70, but this is not limited to this. The predetermined number of people can be set appropriately based on the usage method of the building 10, the type of event, etc.

[Action and Effect]
Next, the operation and effects of this embodiment will be described.

In the vibration-isolation floor structure 102 of this embodiment, the restraint mechanism 100 is restrained from moving vertically by friction, so shaking of the vibration-isolation floor 70 is suppressed when a person on the vibration-isolation floor 70 performs an action with a small vibration force, such as walking. Therefore, a person on the vibration-isolation floor 70 does not feel or barely feels any vibration that is uncomfortable, or, in sensory terms, a "fluffy feeling."

On the other hand, when a person on the vibration-isolating floor 70 jumps and lands, or performs an action that generates a large vibration force, such as vertical sliding, the friction that restricts the vertical movement of the restraining mechanism 100 breaks, and the vibration-isolating performance of the vibration-isolating device 50 is exerted. This reduces the vibrations that propagate to the buildings 300 and 302 surrounding the structure 10.

In addition, in the vibration-proof floor structure 102, the second housing 160 is joined to the first housing 152 with the second friction plate 162 at the tip in surface contact with the first friction plate 110, and the first housing 152 and the second housing 160 are filled with filler J, which hardens to maintain the surface contact state between the first friction plate 110 and the second friction plate 162. Therefore, while the restraining mechanism 100 restrains horizontal movement relative to the outer periphery 30A of the slab 30 of the vibration-proof floor 70, vertical movement can be restrained by friction between the first friction plate 110 and the second friction plate 162 in surface contact.

Furthermore, if the upper limit value at which friction breaks down is the vertical force of the vibration isolation floor 70 as _T0 (N), the excitation force generated by a person walking on the vibration isolation floor 70 as _T2 (N), and the excitation force generated by a person jumping and landing on the vibration isolation floor 70 as _T2 (N), then they are set so that _T2 > _T0 ≧ _T1 holds. Therefore, when a person on the vibration isolation floor 70 walks, the shaking of the vibration isolation floor 70 is suppressed, and when a person on the vibration isolation floor 70 jumps and lands, the vibration isolation performance of the vibration isolation device 50 is demonstrated.

[Measurements using a mock-up of an anti-vibration floor structure]
Next, a description will be given of measurements performed to confirm the performance of the restraint mechanism 100 using a mock-up of a vibration-isolation floor structure, and the results thereof.

(Specifications for vibration-proof floor mockup)
First, the specifications of the mockup will be explained.

In the mockup 104 shown in Figures 6(A) and 6(B), a concrete mass 75 serving as a measurement model of the vibration-proof floor 70 (see Figure 1) is supported by a number of coil springs 53 provided at the bottom 35C of a concrete support section 35 having a retaining wall 35A formed on the outer periphery. A viscous damper 55 (see Figure 6(A)) is connected between the concrete mass 75 and the bottom 35C. The design value of the natural frequency of the concrete mass 75 in the vertical direction is set to 1 Hz.

As shown in FIG. 6B, the mockup 104 is provided with a stopper mechanism 78. The stopper mechanism 78 is composed of a protruding portion 77 that protrudes from the bottom of the concrete mass 75 and a restricting portion 79 that is provided on the bottom 35C and surrounds the periphery of the protruding portion 77.

Note that Fig. 6(A) and Fig. 6(B) are schematic illustrations. Therefore, the coil spring 53 and the viscous damper 55 are schematic illustrations, and hatching and the like showing the cross sections of each component are omitted. Also, in Fig. 6(A), the coil spring 53 and the viscous damper 55 are illustrated with solid lines.

A restraining mechanism 100 is provided between the side wall 75B of the outer periphery 75A of the concrete mass 75 and the side wall 35B of the retaining wall 35A. The restraining mechanism 100 has the same configuration and construction method as the above-mentioned embodiment, so a description thereof is omitted. The dynamic friction coefficient μ acting between the first friction plate 110 and the second friction plate 162 (see FIG. 3) is 0.06.

Here, retaining wall 35A is not formed on the left side in FIG. 6(A). Mockup 104 is an experimental device, and in addition to this measurement, various other experiments are performed. Therefore, to ensure access to coil spring 53 and viscous damper 55 and visibility during measurement, retaining wall 35A is not formed on the left side in the figure.

(Measuring method)
Next, the measurement method will be described.

The large vibration exciter 200 and the small vibration exciter 210 are placed on top of the concrete mass 75. The large vibration exciter 200 performs sine wave excitation, 3.06 Hz in this measurement, and while maintaining this state, the small vibration exciter 210 performs a sweep excitation from 0.5 Hz to 20 Hz.

(Measurement result)
Next, the measurement results will be described.

Figure 7 shows the accelerance (vibration characteristics) of the concrete mass 75 when the output of the large vibration exciter 200 is adjusted to gradually increase the amplitude of the concrete mass 75. Note that "accelerance" is equivalent to the response acceleration of the concrete mass 75 obtained when a sinusoidal vibration of each frequency is applied with a vibration force of 1 kN to the vibration frequency range of 0.5 Hz to 20 Hz excited by the small vibration exciter 210.

The graph lines R1, R2, R10, R20, R45, R120, R290, and R620 in FIG.
R1: Amplitude 0 μm (no vibration)
R2: No restraint mechanism (before restraint mechanism is installed)
R10: Amplitude 10 μm
R20: Amplitude 20 μm
R45: Amplitude 45 μm
R120: Amplitude 120 μm
R290: Amplitude 290 μm
R620: Amplitude 620 μm

As mentioned above, the frequency of the sine wave excited by the large vibration exciter 200 is 3.06 Hz. Around this frequency of 3.06 Hz, the vibration components originating from the large vibration exciter 200 become dominant, and the vibration components originating from the small vibration exciter 210 are relatively minimized. Therefore, the data around the frequency of 3.06 Hz is extremely unreliable, and no valid data can be obtained. Therefore, the results from 2.5 Hz to 3.5 Hz have been omitted from Figure 7.

The graph in Figure 7 shows that the acceleration has a significant amplitude dependency on the displacement of the concrete mass 75.

Specifically, it can be seen that as the output of the large vibration exciter 200 increases, in other words, as the amplitude of the concrete mass 75 increases, the vibration isolation performance approaches that of the concrete mass 75 without the restraint mechanism 100 ("R2: without restraint mechanism (before installation of restraint mechanism)"), that is, the original vibration isolation performance of the concrete mass 75. Therefore, it can be seen that even with the restraint mechanism 100 installed, vibration isolation performance is exhibited when vertical rolling (jump landing) is performed.

On the other hand, when the output of the large vibration exciter 200 is small, in other words when the amplitude of the concrete mass 75 is 10 μm to 20 μm (R10 and R20), this corresponds to the vibration characteristics when performing actions with small vibration forces, such as walking or jogging. Furthermore, compared to the peak frequency of 1.13 Hz for an amplitude of 620 μm (R620), which is close to the original vibration isolation performance of the concrete mass 75 described above, the response of the concrete mass 75 at 1.13 Hz for an amplitude of 10 to 20 μm is suppressed to about one-tenth of that. Therefore, it can be confirmed that the provision of the restraint mechanism 100 makes it possible to suppress the vibration of the concrete mass 75 caused by actions with small vibration forces, such as walking or jogging.

To be more specific, in the cases of "R1: amplitude 0 μm (no excitation) no excitation" and "R10: amplitude 10 μm" and "R20: amplitude 20 μm" with smaller displacement amplitudes, the friction of the restraining mechanism 100 has a large effect, and the natural frequency of the low-frequency vibration-isolated floor, which was 1.25 Hz in "R2: no restraining mechanism (before installation of the restraining mechanism)", improves to 6.3 Hz to 12.5 Hz, and the acceleration below 5 Hz becomes smaller.

In addition, the larger the displacement amplitude, the smaller the effect of friction of the restraint mechanism 100, and the greater the accelerance below 5 Hz. For example, in the case of "R620: amplitude 620 μm," the natural frequency is 1.13 Hz, about 10% lower than "R2: no restraint mechanism (before installation of the restraint mechanism)," and the peak value of the accelerance is about 30% lower.

Figure 8 is a graph showing the relationship between the displacement amplitude of the concrete mass 75 and the acceleration reduction ratio at vibration frequencies of 1.25 Hz, 1.6 Hz, 2.0 Hz, and 2.5 Hz in Figure 7. Specifically, the acceleration reduction ratio was calculated as the ratio of the value of "R1: amplitude 0 μm (no excitation) no excitation" to the value when a displacement amplitude was applied. Note that 1.25 Hz, 1.6 Hz, and 2.0 Hz are pitches that assume walking. 2.5 Hz is a pitch that assumes jogging.

From Figure 8, it can be seen that the larger the displacement amplitude and the lower the vibration frequency, the lower the accelerance reduction ratio. Specifically, for "R620: Amplitude 620 μm", the accelerance is reduced to about 1/32 at 1.25 Hz, about 1/13 at 1.6 Hz, about 1/6 at 2.0 Hz, and about 1/2 at 2.5 Hz compared to "R1: Amplitude 0 μm (no excitation) no excitation", confirming that vibration isolation performance is demonstrated when the excitation force is large.

In addition, for "R10: amplitude 10 μm" and "R20: amplitude 20 μm," there is no significant difference from "R1: amplitude 0 μm (no excitation)" for any of the vibration frequencies, and it can be confirmed that the concrete mass 75 is restrained when the excitation force is small.

From the above results, it was confirmed that the vibration isolation floor structure 102 has an effect of suppressing the shaking of the vibration isolation floor 70 when a person on the vibration isolation floor 70 performs an action with a small vibration force, such as walking, because the restraint mechanism 100 restrains vertical movement by friction, and prevents the person on the vibration isolation floor 70 from feeling uncomfortable vibrations, or in other words, a "fluffy feeling." On the other hand, when a person on the vibration isolation floor 70 performs an action with a large vibration force, such as jumping and landing, or so-called vertical sliding, the friction restraining the vertical movement of the restraint mechanism 100 is broken, and the vibration isolation performance of the vibration isolation device 50 is exerted. It was confirmed that this reduces the vibrations propagating to the buildings 300, 302 surrounding the structure 10.

(Example of rough calculation based on measurement results)
Next, an example of rough calculations of the vertical Q of the concrete mass 75, which is the excitation force _T0 that is the maximum frictional force of the restraint mechanism 100 in the mockup 104 shown in Figures 6 (A) and 6 (B), the normal force N, and the excitation force _T1 when two people walk on the concrete mass 75 will be described.

In FIG. 7, if the results up to "R20: Amplitude 20 μm" are considered to be approximately equivalent to "R1: Amplitude 0 μm (no vibration)", the large vibration exciter 200 has an amplitude of 20 μm at 3.06 Hz.
Acceleration is calculated by "amplitude x (2πf) x 2",
Acceleration = 20 [μm] x (2π x 3.06 [Hz]) x 2 = 0.0074 [m/s ² ]
Since the weight of the concrete mass 75 is 60 t, the vertical force Q of the concrete mass 75 is
Vertical force Q = 60 [t] x 0.0074 [m/ ^s2 ] = 0.444 [kN]
The coefficient of dynamic friction μ is 0.06.
The normal force N = 0.444 [kN] / 0.06 = 7.4 [kN].

In addition, when two people actually walked on the concrete mass 75, the concrete mass 75 was restrained, and they did not feel any "fluffiness."

When two people walk, the excitation force _T1 is, assuming that the average body weight is 60 kg and _α1 is 0.4,
√2 x (60 kg x 9.8) x 0.4 ≒ 0.333 [kN]
It becomes.

If we consider the vertical force Q of the concrete mass 75, 0.444 [kN], to be the upper limit of the resistance force due to static friction, in other words, the excitation force _T0 which results in the maximum friction force _F0 , then the excitation force _T1 of 0.333 [kN] when two people walk on the concrete mass 75 is below this limit, which coincides with the fact that two people actually walked on the concrete mass 75 and did not feel a “fluffy feeling.”

＜Other＞
The present invention is not limited to the above embodiment.

For example, in the above embodiment, the restraint mechanism 100 is provided with the housing 150 having the second friction plate 162 and the filler J on the outer peripheral portion 30A side, and the first friction plate 110 on the vibration-isolating floor 70 side, but is not limited to this. The housing 150 having the second friction plate 162 and the filler J may be provided on the vibration-isolating floor 70 side, and the first friction plate 110 may be provided on the outer peripheral portion 30A side.

In addition, for example, in the above embodiment, the restraining mechanism 100 is provided between the side wall 30B of the outer periphery 30A of the slab 30 and the side wall 70B of the outer periphery 70A of the vibration-isolating floor 70, but this is not limited to this. For example, it may be provided between the bottom plate 36 of the slab 30 and the vibration-isolating floor 70. In this case, for example, members such as the protrusion 77 and the regulating portion 79 of the stopper mechanism 78 of the mockup 104 shown in FIG. 6(B) may be provided on the bottom plate 36 of the slab 30 and the vibration-isolating floor 70, and the restraining mechanism 100 may be provided between these protrusions 77 and the regulating portion 79.

The restraint mechanism 100 is configured to include a first friction plate 110, a housing 150 having a second friction plate 162, and a filler J, but is not limited to this. Any mechanism may be used as long as it restrains the vertical movement of the vibration isolation floor 70 due to friction when a person on the vibration isolation floor performs an action with a small vibration force, such as walking, and breaks down the friction and allows the vibration isolation device to demonstrate vibration isolation performance when the person on the vibration isolation floor performs an action with a large vibration force, such as vertical sticking.

Furthermore, the present invention can be implemented in various ways without departing from the spirit of the invention.

REFERENCE SIGNS LIST 10 Building 32 Structure 50 Vibration isolation device 70 Vibration isolation floor 75 Concrete mass 100 Restraint mechanism 102 Vibration isolation floor structure 104 Mock-up 110 First friction plate 150 Housing 152 First housing 160 Second housing 162 Second friction plate J Filler

Claims (5)

A vibration-isolating floor provided in a building constructed on the ground ;
A vibration isolation device that is installed on a bottom plate constituting a structural body of the building and supports the vibration isolation floor;
a restraining mechanism that is provided between the slab constituting the structure and the vibration isolation floor, and that restrains the horizontal movement of the vibration isolation floor relative to the slab and causes the vibration isolation device to exhibit vibration isolation performance when friction that restrains the vertical movement of the vibration isolation floor relative to the slab is broken;
Vibration-proof floor structure equipped with The restraint mechanism includes:
A first friction plate provided along a vertical direction on one of the structure or the vibration-isolating floor;
A first housing protruding horizontally from the other of the structure or the vibration-isolating floor;
a second housing slidably provided on the first housing and joined to the first housing with a second friction plate at a tip end thereof in surface contact with the first friction plate;
a filler that is filled into the first housing and the second housing and hardens to maintain a surface contact state between the first friction plate and the second friction plate;
The vibration-isolating floor structure according to claim 1 . The restraint mechanism includes:
The vibration force at which the friction breaks is defined as Q (N), which is the vertical force of the vibration-isolating floor.
The excitation force generated by a person walking on the vibration-isolation floor is defined as T ₁ (N),
If the excitation force generated by a person jumping and landing on the vibration-proof floor is _T2 (N), then:
_T2 >Q> _T1
is set so that
The vibration-isolating floor structure according to claim 1 or 2. The natural frequency of the vibration-isolating floor is set to 1 Hz or less,
The frequency of the jump landing is 2.0 Hz to 3.0 Hz.
The vibration-isolating floor structure according to claim 3. A vibration isolation floor supported by a vibration isolation device installed in the structure;
a restraining mechanism that is provided between the structure and the vibration-isolating floor, and that restrains horizontal movement of the vibration-isolating floor relative to the structure and causes the vibration-isolating device to exhibit vibration isolation performance when friction that restrains vertical movement is broken;
Equipped with
The restraint mechanism includes:
A first friction plate provided along a vertical direction on one of the structure or the vibration-isolating floor;
A first housing protruding horizontally from the other of the structure or the vibration-isolating floor;
a second housing slidably provided on the first housing and joined to the first housing with a second friction plate at a tip end thereof in surface contact with the first friction plate;
a filler that is filled into the first housing and the second housing and hardens to maintain a surface contact state between the first friction plate and the second friction plate;
A vibration-proof floor structure having the above structure.