JPH11350515A - Vibration proof structure of underground structural body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the effect of vibration proofing of vibration proof structure in an underground structural body of a building from being lost even if the rigidity on an earth retaining side coming into contact with the underground structural body is lost in a state that a vibration-proofing layer is thin. SOLUTION: A rubber isolator 20 is laid between a floor slab 10 and an earth retaining A side. Then, the vibration-proofing layer 40 of a polyethylene foaming material selected as an index of having an impedance Z (kg/s.M<2> ) obtained from the product of density D (kg/m<3> ) by longitudinal wave velocity of propagation V (m/s) within range set by adjusting it to a required amount of vibration to be reduced is interposed between an external wall 30 constructed downward of the floor slab 10 and earth retaining A side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping structure for an underground structure for preventing vibration or the like during traveling on a subway that propagates through the ground to an underground structure such as a building.

[0002]

2. Description of the Related Art In recent years, underground traffic networks, such as railroads and motorways, have been remarkably developed in urban areas for the purpose of effectively using land. In addition to these transportation networks, underground parts include theaters and halls as public underground facilities,
Alternatively, a facility such as a broadcasting studio, which particularly requires a quiet indoor environment, has been constructed.

In order to construct an underground structure of a building including an underground facility or the like, a construction area of the underground structure is excavated in advance.
From the underground part to the ground, each floor part of the underground structure is built up in a stacked manner, and conversely, after building the skeleton part on the ground floor side first, building each basement floor while gradually increasing the excavation depth There is known a reverse striking method that proceeds downward.

In the conventional reverse striking method, as shown in FIG. 13, a protruding portion 2 is provided on the peripheral edge of the floor slab 1 so as to protrude toward the mountain retaining A side, and the protruding portion 2 is directly connected to the mountain retaining A side. And a structure capable of receiving a concentrated load from the buckle A during construction.

When a mountain retaining wall is formed on the mountain retaining A side, the protruding portion 2 comes into contact with the mountain retaining wall. In addition, when the mountain retaining A side is used as the excavated ground as it is, the protruding portion 2 comes into direct contact with the excavated ground surface.

In the above-described structure, the load at the time of the reverse striking method is supported by bringing the floor slab 1 into direct contact with the buckle A side. From the floor slab 1, the outer wall 3 of the underground structure is formed by reverse striking of concrete, as shown in FIG.

[0007] Between the outer wall 3 and the lands A
A foam polystyrene board 4 is interposed to support a load from the side. After the floor slab 1 is constructed, a foam polystyrene board 4 having a predetermined layer thickness (generally, about 300 mm) is attached to the mountain retaining A side, and a weir plate is provided at a predetermined interval from the surface of the foam polystyrene board 4. Then, a formwork is formed downward from the bottom side of the floor slab 1, and concrete is reversely hit into the formwork, so that the formwork is interposed between the outer wall 3 and the pier A.

In the above structure, the floor slab 1 is directly in contact with the lands A, so that through this contact portion, vibration energy such as the vibration of a subway travels to the floor slab 1 and the underground structure As a whole, the anti-vibration effect is significantly reduced.

There is also an example in which the space is left as it is without any intervening between the outer wall 3 and the mountain retaining A side, but in such a configuration, groundwater flows into this space from the mountain retaining A side, and the space portion is Vibration propagation occurs through the water that has accumulated in the water.

Therefore, in order to improve the vibration isolation of the underground structure in the reverse striking method, as shown in FIG.
Between the protruding end of the protruding portion 2 and the side of the retaining A
Is interposed.

When the vibration isolating rubber 5 is interposed as described above, a load is not applied to the outer wall 3 immediately after the floor slab 1 is constructed by the reverse striking method. As the interposed foam polystyrene board 4, a thin layer having a thickness of about 100 mm is used.

[0012]

However, the vibration-proof rubber 5,
Also, in the above-described structure in which the foam polystyrene board 4 is interposed between the underground structure and the mountain retaining A side, a load from the ground on the mountain retaining A side is gradually applied to the foam polystyrene board 4 as time passes after construction.

On the other hand, a mountain retaining wall is provided on the mountain retaining A side, and the anti-vibration rubber 5 and the foam polystyrene board 4 are interposed in the conventional manner between the mountain retaining wall and the underground structure, but are provided in the ground. Unless the retaining wall is a permanent structure that does not change over time, it generally deteriorates with aging, and in the long term the retaining wall is integrated with the ground, and the retaining wall that originally supported the load on the ground can no longer support the load on the ground, The load is applied to the foam polystyrene board 4 correspondingly, and the vibration energy generated during running on a subway, for example, propagates. However, since the thickness is thin, a sufficient vibration-proof effect cannot be obtained.

That is, during the period in which the retaining wall is regarded as a rigid body, no load is applied to the foam polystyrene board 4, so that the vibration energy during railroad travel is not propagated, but the rigidity of the retaining wall is lost and the foam is lost. A load is applied to the polystyrene board 4 and the vibration energy is also propagated, and the vibration cannot be completely absorbed at such a thickness.

[0015] By reducing the vibration isolation effect, in a building having such an underground structure, the solid sound relating to the above-described vibration propagation in the ground is radiated as noise, and a quiet indoor environment cannot be obtained. Become.

In consideration of the above, the side of the retaining wall A and the outer wall 3
Is about 10
About 0 mm is not enough, and from the long-term point of view, it is necessary to take measures such as using a layer having a thickness of about 300 mm. However, from the viewpoint of workability and the like, it is preferable that the vibration damping layer to be interposed is thin.

An object of the present invention is to provide an anti-vibration structure for an underground structure while realizing that the anti-vibration effect is not lost even if the rigidity of the mountain retaining side in contact with the underground structure is lost. An object of the present invention is to reduce the thickness of the vibration isolation layer.

An object of the present invention is to reduce noise caused by solid-state noise related to propagation of vibrations in the ground in a room of a building having an underground structure.

[0019]

SUMMARY OF THE INVENTION The present invention relates to a vibration damping structure for an underground structure provided in the underground of a building, wherein the projecting portion is provided on a periphery of a floor slab of the underground structure. Between the earth retaining side of the excavated ground in the ground, an anti-vibration rubber provided laterally in accordance with the height and length of the protruding portion, and an outer wall provided below the floor slab, And a vibration-proof layer of a polyethylene-based foam material provided between the grounding side.

The protruding portions are respectively provided on the periphery of the floor slab on each basement floor of the underground structure, and the height of the protruding portion and the height of the protruding portion are provided between the mountain retaining side and the protruding portion. Anti-vibration rubbers are provided in the lateral direction according to the length, and the upper and lower sides are sandwiched between the anti-vibration rubber and the outer wall provided between the floor slabs of the upper and lower basement floors. And
It is characterized in that a vibration-proof layer of a polyethylene foam material is provided.

The anti-vibration rubber provided between the protruding portion of the peripheral edge of the floor slab of each basement floor and the mountain retaining side is more resistant to a load from above as the depth of the underground where the anti-vibration rubber is provided is deeper. The height is gradually set accordingly.

The polyethylene foam has a density D (k
g / m ³ ) and the impedance Z (kg / s · m ² ) obtained by multiplying the longitudinal wave propagation velocity V (m / s) are within a set range according to a desired amount of vibration reduction. It is characterized by being selected as an index.

The polyethylene foam has an impedance Z (kg / s · m ² ) of 2000 to 5000.
(Kg / s · m ² ) is selected within the set range to reduce the propagation of subway running vibration to the underground structure.

In the reverse striking method, the outer slab and the floor slab on the lower floor are gradually provided below the previously constructed floor slab, so that the floor slab needs to support the load from the mountain retaining side. For this reason, an anti-vibration rubber is interposed between the floor slab and the retaining side to prevent vibration propagation through the floor slab.

By forming the vibration-proof layer provided between the mountain retaining side and the outer wall from a polyethylene-based foam material, the mountain retaining side including the mountain retaining wall ages and loses rigidity. For example, the mountain retaining wall is integrated with the ground. Loses its rigidity,
Even if a load is applied from the mountain retaining side, a sufficient vibration damping effect can be maintained for a long period of time due to the vibration damping effect as an elastic body and the damping effect inside the material.

As such a polyethylene foam, for example, SV-E (trade name) manufactured by Sekisui Plastics Co., Ltd.
At the moment it turned out to be favorable.

In particular, among the physical properties of the polyethylene foam used, the density D (kg / m ³ ) and the longitudinal wave velocity V
(M / s) and the value of impedance Z obtained by multiplying by
It was found that when a foamed material falling within the range of 2000 to 5000 (kg / s · m ² ) was selected, for example, the vibration damping effect against running vibration of a subway track was good. Vibration caused by running the subway propagates to the underground structure, so that it is possible to reduce solid-state noise radiated as noise in a building having the underground structure.

Particularly, among the above-mentioned SV-Es, the SV-E
33 has a density of about 33 (kg / m ³ ), a longitudinal wave propagation velocity of about 67 (m / s), an impedance Z of about 2200, and has a good anti-vibration effect at a frequency around 63 Hz when running on a subway. It turned out to be. That is, it is possible to effectively reduce indoor noise caused by running a subway in a building having an underground structure.

If such a polyethylene foam is used as the vibration-proof layer, the layer thickness can be reduced. For example, even if the layer thickness is set to about 100 mm, a sufficient vibration damping effect can be expected for a long period of time even if the retaining side loses rigidity.

The Young's modulus of the polyethylene foam used as the vibration isolating layer is preferably in the range of 1 × 10 ⁵ to 10 ⁶ N / m ² . Within this range, the rigidity on the mountain retaining side is lost, and the vibration-proof effect is not lost even if a load is applied to the vibration-proof layer side of the polyethylene-based foam.

The impedance Z obtained from the product of the longitudinal wave propagation velocity and the density of the polyethylene foam material is 500
0 or less is preferable. In an experiment by the present inventor, an effective vibration damping effect against noise during traveling on a subway was obtained by using a polyethylene foam material having an impedance Z of about 2000.

When the impedance Z exceeds 5,000, the amount of attenuation is small and an effective anti-vibration effect cannot be expected. However, at present, if a material is selected within the range of 2000 to 5000, a good anti-vibration effect can be obtained. Is considered to be obtained.

For example, a rubber having a rubber hardness of JIS
A plate rubber of 30 ° to 70 ° of A may be used,
KLM100 (trade name) manufactured by Bridgestone Corporation can be used.

In an underground structure having a plurality of basement floors, a projecting portion is provided at the periphery of the floor slab of each basement floor toward the mountain retaining side, and an anti-vibration rubber is provided between the projecting portion and the mountain retaining side. May be interposed.

With respect to the above-mentioned anti-vibration rubber provided on each basement floor, the load applied from above increases as the construction depth of the basement floor becomes deeper. It is preferable that the height in the direction is gradually increased.

Since the load per unit area is the same,
The natural frequency of the system by the vibration isolating rubber becomes the same, and the same vibration isolating effect can be obtained.

Further, since the price of the vibration-proof rubber is high, such a structure requires a necessary vibration-proof rubber as compared with the case where the same height is used from the top floor to the bottom floor of the basement floor. The construction cost of the anti-vibration rubber can be reduced without sacrificing the vibration effect.

Further, if a vibration-proof layer is provided between the vibration-proof rubbers on the upper floor side and the lower floor side by interposing the polyethylene foam material having the above-mentioned structure, the outer wall at each basement floor can be provided. The anti-vibration structure between the and the buckle side is configured.

When providing a vibration-proof rubber and a vibration-proof layer made of polyethylene-based foam material, the rubber vibration-proof rubber must be provided on the retaining side before the concrete is cast by the reverse striking method to form a floor slab or the like. A dam is provided at a predetermined distance from the vibration-isolating layer to form a formwork, and concrete is reversely hit into the formwork, so that the formwork can be interposed between the underground structure and the retaining side.

The mounting of the vibration-proof rubber and the vibration-proof layer on the side of the polyethylene foam material at the mountain retaining side may be performed via an adhesive or the like. Such a polyethylene-based foam material is used in place of a mold when forming the outer wall.

In order to easily perform the connection between the vibration isolating rubber and the vibration isolating layer made of the polyethylene foam, irregularities for fitting may be provided on both sides.

The vibration-proof rubber is provided along the projecting portion of the peripheral edge of the floor slab. The vibration-proof rubber is provided intermittently along the projecting portion, and the section where the vibration-proof rubber is lacking is formed by the polyethylene having the above structure. The anti-vibration rubber and the polyethylene-based foam may be mixed alternately with the intermediary of the foamed material.

By adopting the structure of the present invention,
For example, when performing the underground part by the reverse driving method, during the construction and for a while after construction of the underground structure etc., the retaining side including the SMW retaining wall etc. can be regarded as a rigid body,
The earth pressure due to the ground is applied to the underground structure only at the projecting portion of the floor slab via the vibration-proof rubber.

On the other hand, if the mountain retaining wall is aged over time after completion, the mountain retaining wall may not be rigid and may behave similarly to the ground. Even in such a case, the vibration-proof layer of the polyethylene foam material interposed between the retaining wall and the concrete outer wall exhibits the effect, and the vibration energy reduced by the vibration-proof effect propagates to the underground structure.

In this way, if the vibration-proof structure of the underground structure is made to have a hybrid structure having a vibration-proof rubber and a vibration-proof layer made of polyethylene foam, a high level of vibration protection can be achieved over a long period from the time of completion. A structure that can maintain vibration performance can be realized.

Therefore, an underground facility that requires a quiet indoor environment can be constructed beside an underground transportation network such as a subway, which is a source of vibration that causes indoor noise.

[0047]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) In this embodiment, FIG.
As shown in the figure, an underground structure of a building is constructed in the ground. As shown in the sectional view of FIG. 1, the floor slab 10 on the ground side of the underground structure projects horizontally 1
1 is formed. An anti-vibration rubber 20 is interposed between the projecting end of the projecting portion 11 and the side of the mountain retaining A surface.

As the vibration isolating rubber 20, a conventionally used rubber having a high vibration absorbing ability may be used. Examples of such anti-vibration rubber include KL manufactured by Bridgestone Corporation.
M100 (product name).

The anti-vibration rubber 20 is formed in a substantially rod-like shape with a square cross section corresponding to the height of the protruding portion 11, as shown in FIG.
As shown in FIG. 2, it is provided in a strip shape along a projecting portion 11 provided around a floor slab 10 of the underground structure.

In FIG. 2, the floor slab 10 is provided so as to surround three sides around the floor slab 10 for a vibration source X such as a subway passing in the ground near the underground structure.
By surrounding at least three sides of the floor slab 10 with the vibration isolating rubber 20, it is possible to prevent the propagation of vibration from the vibration source X from the front or the side.

If it is sufficiently considered that the vibration propagates to the rear side, it is possible to surround the four sides of the floor slab 10 with the vibration-proof rubber 20 including the rear side.

As described above, the outer wall 30 is provided below the floor slab 10 surrounded by the vibration isolating rubber 20 and separated by a predetermined distance from the vertical plane of the ridge A. Exterior wall 3
Numeral 0 is integrally constructed from the lower surface of the floor slab 10 by means of back-casting concrete.

An anti-vibration layer 40 is interposed between the outer wall 30 and the surface A of the mountain clasp. As the vibration-proof layer 40, a board made of a polyethylene foam material having a constant thickness is used. When selecting a polyethylene foam, the density D (kg /
m ³ ) and the impedance Z obtained by multiplying the longitudinal wave propagation velocity V (m / s) within a range in which a desired amount of vibration reduction can be obtained according to the vibration frequency of the vibration source X. Should be set.

In FIG. 1, the anti-vibration rubber 20 and the anti-vibration layer 40 are provided on the vertical surface of the lands A through an adhesive such as mortar, but as shown in FIG. The mountain retaining wall 50 may be provided at the bottom.

As the mountain retaining wall 50, for example, SM
What is necessary is just to build a W mountain retaining wall. The earth pressure of the ground applied to the retaining wall 50 is concentrated on the building floor slab position in a sectional view. Therefore, even when the retaining wall 50 is constructed on the retaining A side, the anti-vibration rubber 20 is provided between the retaining wall 50 and the underground structure.

When providing the vibration isolating rubber 20, the SMW
In the case of a retaining wall, the H-shaped steel of the parent pile surface and the projecting portion 11 are used.
The anti-vibration rubber 20 may be provided in between.

Further, between the retaining wall 50 and the outer wall 30, an anti-vibration layer 40 made of a board having a predetermined thickness of the polyethylene foam having the above-described structure may be interposed.

When the polyethylene foam board of the vibration isolating rubber 20 and the vibration isolating layer 40 is provided on the surface side of the retaining wall 50, a synthetic adhesive or a double-sided tape may be used. With this configuration, the rigidity of the retaining wall 50 is lost for a long time after construction, and the retaining wall 50
Even if a load is applied to the vibration isolating layer 40 from the ground side integrally with the ground on the side, the vibration transmission from the ground side is reduced while the vibration isolating layer 40 supports the load.

Between the underground structure and the retaining A side, a vibration-proof rubber 20 and a vibration-proof layer 40 made of polyethylene foam are used.
In order to intervene, for example, after excavating a portion corresponding to the first basement floor, on the retaining pier A surface that appeared in the excavation pit, or on the vertical surface of the retaining pier 50 that was built in the ground before excavation,
The polyethylene foam board of the vibration isolating rubber 20 and the vibration isolating layer 40 provided as described above is provided by using, for example, mortar or the like as an adhesive.

From the anti-vibration rubber 20 provided on the mountain retaining A side, a damping plate is opposed at a predetermined interval via a spacer or the like to form a floor slab casting form, and concrete is cast into the form. Floor slab 10 on the ground floor side and projecting portion 1
1 are integrally formed. An anti-vibration rubber 20 is interposed between the projecting portion 11 of the floor slab 10 and the mountain retaining A side.

Thereafter, a board made of a polyethylene foam material having a predetermined thickness is provided on the mountain retaining A side to form a vibration isolating layer 40, and concrete for an outer wall is cast using the board as a formwork. When the outer wall 30 is configured in this manner, the outer wall 3
An anti-vibration layer 40 can be interposed between 0 and the side of the mountain retaining A.

(Embodiment) In this embodiment, the anti-vibration effect of the anti-vibration structure having the above-described configuration when the subway passing near the underground structure is used as the main vibration source X was verified.

In this embodiment, the impedance Z is set to 200 so that a desired vibration damping effect can be obtained even when the traveling vibration of the subway passing near the underground structure propagates to the underground structure.
The polyethylene foam used for the vibration isolating layer 40 was selected so as to fall within the range of 0 to 5000 (kg / s · m ² ).

According to such selection criteria, at present, physical properties,
SV-E (trade name) manufactured by Sekisui Plastics Co., Ltd. was determined to be preferable in terms of both prices and used. It turned out that SV-E33 is particularly preferable among the various specifications of SV-E.

SV-E33 has a density of 33 kg / m
^{At 3} , the longitudinal wave propagation velocity is about 67.42, and the impedance expressed by the product of these is about 2225. When the traveling vibration of the subway is used as the main vibration source, the impedance Z falls within the selection range of 2000 to 5000 (kg / s · m ² ).

If it is not necessary to consider the price, it is possible to use, for example, Shiromer (registered trademark) manufactured by Getzner.

In the experiment, as shown in FIG. 4, the subway traveling range Y was placed on the ground surface where the subway runs vertically below the ground.
(Indicated by a broken line in the figure), the test specimen 100 is arranged within the subway traveling range Y, and the vibration of the test specimen 100 and the ground surface is measured, and the vibration isolation effect of the test specimen 100 is verified. I went as far as I could.

The test body 100a (100) is shown in FIG.
As shown in the figure, the concrete base 11
0 is provided thereon, and a polyethylene-based foamed material 120 made of the above-mentioned SV-E and having a predetermined layer thickness is placed on the anti-vibration layer 40. A concrete block 130 having a predetermined thickness that can be lifted by a crane is placed on the polyethylene foam (SV-E) 120.

The cross-sectional structure of the test piece 100a shown in FIG. 5 (a) is similar to the anti-vibration structure provided with the mountain retaining wall 50 shown in FIG. The structure conforms to a structure in which the vibration isolation layer 40 is interposed therebetween.

The test piece 100b (10) shown in FIG.
0) is configured according to the structure in which the vibration isolating rubber 20 shown in FIG. A substantially rectangular anti-vibration rubber 140 made of the same material as that of the anti-vibration rubber 20 is placed on the four corners of the test piece 100b through a substantially rectangular base 150 made of the same concrete having the same mixing ratio as the concrete base 110. Put.

In the polyethylene foam 120 used as the test piece 100b shown in FIG. 5 (b), notches are provided in advance at four corners for installation of the anti-vibration rubber pieces 140 and the like.
The vibration-proof rubber 140 and the polyethylene-based foam material 120 are configured so as to be flush with each other with the four corners 40 placed. The test block 100b is configured by placing the concrete block 130 having the above configuration thereon.

The anti-vibration rubber 140 is formed in a quadrilateral having a predetermined layer thickness, and in this embodiment, a 170 mm square and a 145 mm square are used.
The type was used to verify the anti-vibration effect. This is because the underground structure having a plurality of basement floors has a vibration-proof rubber 2
0 is to change the height in the vertical direction in accordance with the installation depth of the anti-vibration rubber 20, and to confirm the influence on the anti-vibration effect when the size of the anti-vibration rubber 20 is changed.

The case where the vibration isolating layer 40 is provided using the test piece 100a shown in FIG. 5A and the case where the concrete base 110 is provided without the vibration isolating layer 40 as shown in FIG.
The vibration state was compared using the test piece 100c on which the concrete block 130 was directly mounted without using the polyethylene-based foam material 120.

In this embodiment, as shown in FIG. 6B, a test piece 100d (100) in which a polyethylene foam material 120 is intermittently provided between a concrete block 130 and a concrete base 110 is used. Also verified the effect.

By using the test piece 100b shown in FIG. 5B, the vibration reducing effect of the structure shown in FIG. 3 using the vibration-proof rubber 20 and the vibration-proof layer 40 together can be measured.

At the time of actual vibration measurement, as shown in FIG. 4, each of the test pieces 100a, 100b, 100c, 100c
d are spaced apart from each other by a predetermined distance, and a base 160 for ground vibration correction is provided beside it, and the test pieces 100a, 100b, 1
The vibrations of 00c and 100d and the vibration of the base 160 were measured at the same time, and the vibration measured by the base 160 was corrected to be the vibration of each test piece 100a. The results of such an experiment are shown in the graph of FIG.

In FIG. 7, the vibration frequency (Hz) is plotted on the horizontal axis, and the vibration isolation effect (dB) is plotted on the vertical axis. The case where the vibration isolation layer 40 is not provided is set as a reference (0). And the case where the vibration-proof layer 40 and the vibration-proof rubber 20 are used together, the vibration-proof effect amount is shown.

As can be seen from FIG. 7, when the center frequency of the 1/3 octave band is 25 Hz or more, when the vibration isolating layer 40 using the polyethylene foam material 120 is provided (in the case of the test piece 100a), the vibration isolating rubber 140 When the vibration-proof layer 40 using the polyethylene foam material 120 is used together (when 170 mm square and 140 mm square are used in the test body 100 b), the vibration-proof layer 40 is not provided (for the test body 100 c). It can be seen that a greater vibration damping effect can be obtained as compared with the case (1).

In particular, in the vicinity of 63 Hz, which is the frequency of the vibration peak during running on the subway, as shown in FIG.
0a) and the case where the vibration isolating rubber 140 and the polyethylene foam material 120 are used together (test body 100b).
It can be seen that the amount of the vibration isolation effect is large, and an effect of about 20 dB can be obtained.

Further, FIG. 7 shows that the polyethylene foam 120 is used alone (in the case of the test piece 100a), the vibration isolating rubber 140 and the polyethylene foam 120 are used.
It can be seen that the vibration damping effect shows almost the same tendency as in the case of using (sample 100b).

When the vibration isolating layer 40 made of the polyethylene foam 120 is provided intermittently (test piece 100d)
Although not shown in FIG. 7, the vibration-proof effect was hardly obtained, and was the same as when the concrete base 110 was directly connected.

From the results shown in FIG. 7, it can be seen that the anti-vibration structure of the underground structure according to the present invention described in the above embodiment is effective in preventing the propagation of vibration from the side of the buckle A. As a result, in a building having such an underground structure, noise due to the solid-state noise related to the vibration propagation is reduced, and a quiet indoor environment is obtained.

(Embodiment 2) As shown in FIG. 8, the underground structure of the present embodiment is configured up to the third floor underground, and the subway B is passed on the side in the ground.

As shown in FIG. 3, a retaining wall 50 is constructed on the excavation surface side of the retaining A. As the mountain retaining wall 50, an SMW mountain retaining wall is employed. The SMW retaining wall is formed by continuously drilling an excavation hole with an auger in the retaining A, forming a groove in the groove, setting up an H-shaped steel in the groove, further pouring concrete into the groove, and forming a concrete underground continuous wall. It is configured as a wall.

In the floor slab 10 on the ground side, the projecting portion 1
Embodiment 1 between the first retaining wall 50 and the retaining wall 50 having the above configuration.
The anti-vibration rubber 20 is interposed in the construction procedure described above. Under the vibration isolating rubber 20, a vibration isolating layer 40 made of a polyethylene foam board is provided on the outer wall 30 on the first basement floor,
It is interposed between the retaining wall 50. Anti-vibration rubber 2
The materials used in the first embodiment and the vibration isolating layer 40 are those selected in the first embodiment.

The above-mentioned polyethylene-based foam materials include, for example,
The same SV- as used in the example of the first embodiment.
A polyethylene foam material 120 made of E may be used.

FIG. 8 also shows the floor slab 10a on the second basement floor.
As shown in FIG. 5, a projecting portion 11a projecting in the horizontal direction toward the retaining wall 50 is provided, and a vibration-proof rubber 20a is interposed between the projecting portion 11a and the retaining wall 50. . The anti-vibration rubber 20a is made of the same material as the anti-vibration rubber 20 and is set to be higher than the anti-vibration rubber 20 only in the vertical direction. The height of the anti-vibration rubber 20a may be set so as to withstand a load applied to the anti-vibration rubber 20a from above.

The vertical length m of the vibration isolating rubber 20a is configured to be longer than the vertical length l of the vibration isolating rubber 20. The structural part provided with the vibration isolating rubber 20a is
Since the depth in the ground is deeper than the mounting location of the vibration isolation rubber 20,
It is long enough to withstand the load from vertically above.

The vibration isolating layer 40 is provided below the vibration isolating rubber 20a.
a is provided. As the vibration isolating layer 40a, a board made of polyethylene foam having the same material and the same thickness as the vibration isolating layer 40 provided between the outer wall 30 and the retaining wall 50 is used. As shown in FIG. 8, the height of the vibration isolation layer 40a is set in accordance with the height of the outer wall 30a on the second basement floor. In the present embodiment, the outer wall 30a is shorter than the outer wall 20 and has a slightly thicker layer thickness.

In such a structure, as is apparent from the cross-sectional view of FIG. 8, the vibration isolating layer 40 includes the upper and lower vibration isolating rubbers 20 and 20a.
It is configured to be sandwiched between.

The floor slab 10b on the third basement floor following the second basement floor with the above structure also has a projecting portion 11b projecting horizontally toward the retaining wall 50, as shown in FIG.
The anti-vibration rubber 20b is interposed between the projecting portion 11b and the retaining wall 50.

The same material as the vibration-proof rubber 20 is used for the vibration-proof rubber 20b. The height n of the anti-vibration rubber 20b is set to be longer than the height m of the anti-vibration rubber 20a on the second basement floor. In this manner, as the depth of the ground at the installation location becomes deeper, the height of the vibration-isolating rubbers 20, 20a, and 20b used is gradually increased so as to withstand a load from above.

A vibration isolating layer 40b is provided below the vibration isolating rubber 20b. As the vibration-proof layer 40b, a board made of a polyethylene-based foam material having the same material and the same thickness as the vibration-proof layer 40 provided between the outer wall 30 and the retaining wall 50 is used. As shown in FIG. 8, the height of the vibration isolation layer 40b is
The outer wall 3 is set in accordance with the height of the outer wall 30b of the floor portion.
0a, and the layer thickness is thicker than the outer wall 30a.

In the above-mentioned structure, the vibration-proof layer 40 has the floor slabs 10a and 10b on the second basement level and the third basement level, respectively.
Between the anti-vibration rubbers 20a and 20b corresponding to
It has a so-called hybrid structure.

Each of the vibration isolating rubbers 20, 20a, 20b and the vibration isolating layers 40, 40a, 40b are bonded to the retaining wall 50 side each time the progressive reverse driving method is advanced in the same manner as described in the first embodiment. What is necessary is just to adhere | attach via an agent or a double-sided tape.

Forming a form by providing a dam plate at a predetermined distance from the surfaces of the vibration isolating rubbers 20, 20a, 20b and the vibration isolating layers 40, 40a, 40b, and casting concrete into the form Floor slab 10, 10a, 1
0b and the outer walls 30, 30a, 30b may be constructed.

FIG. 9 is a cross-sectional view taken along the line XX of FIG. 8, showing the relationship between the vibration-proof rubbers 20, 20a, 20b and the vibration-proof layers 40, 40a, 40b.

With the above structure, the vibration isolating rubbers 20, 20a, 20b
With a layer thickness 1 of the vibration isolating layer 40 made of polyethylene foam.
The half-width of 00 mm was set to 50 mm, and the effect of vibration during subway running on each of the underground floors was measured on-site. The results are shown in FIGS. In addition, FIG.
The vibration damping effect amount (vibration reduction amount) shown in FIG. 12 is a value obtained from the level difference between the ground vibration, the retaining wall vibration, and the vibration of the underground structure.

FIG. 10 shows the amount of vibration reduction at the first basement floor, which was measured in comparison with the case where the vibration isolating layer 40 was not provided (indicated by a horizontal line at the vibration isolating effect amount 0 in the figure). In the frequency band, it can be seen that the vibration is reduced at a magnitude of about 10 dB to about 30 dB. In the figure, the amount of reduction is indicated by a negative numerical value.

FIG. 11 shows the amount of vibration reduction at the second basement floor. However, as compared with the case where the anti-vibration layer 40 is not provided (shown by a horizontal line at the anti-vibration effect amount 0 in the figure), FIG. As shown in FIG. 7, it can be seen that the vibration is reduced to 10 dB or less. In particular, as compared with FIG. 10, the vibration reduction amount increases as the frequency increases.

FIG. 12 shows the amount of vibration reduction at the third basement floor. FIG. 12 shows a case where the vibration isolating layer 40 is not provided (shown by a horizontal line at a vibration isolating effect amount of 0 in FIG. 10). As shown in FIG. 11, the vibration is reduced to 10 dB or less, and as in FIG. 11, the amount of vibration reduction increases as the frequency increases.

The same experiment as in the above example was conducted with the underground structure of the present embodiment, and similar results were obtained.

As described above, from the results shown in FIGS. 10 to 12, the anti-vibration structure of the underground structure of the present invention described in the present embodiment is as follows.
It can be seen that it is effective in preventing the propagation of vibration from the ridge A side. As a result, in buildings with such underground structures,
The noise due to the solid sound related to the vibration propagation is reduced, and a quiet indoor environment is obtained.

[0105]

According to the present invention, in a building having an underground structure, room noise related to the propagation of vibration to the underground structure in the ground can be reduced.

According to the present invention, even if the rigidity of the retaining structure is lost for a long time after the construction of the underground structure, the anti-vibration effect of the underground structure is not lost.

In the present invention, since the polyethylene foam is used for the vibration-proof layer, the vibration-proof effect of the underground structure can be maintained for a long time even if the vibration-proof layer is made thin.

In the present invention, the height of the vibration isolating rubber is changed according to the installation depth and the load per unit area is made the same. Can not be demonstrated.

In the present invention, the height of the rubber is changed in accordance with the installation depth, and the load per unit area is made the same. Uniform vibration isolation performance is obtained.

In the present invention, even when expensive rubber is used, the height of the rubber is changed in accordance with the installation depth. Thus, construction costs can be reduced.

In the present invention, since the vibration isolating material is selected using the impedance, which is the product of the density of the polyethylene foam material and the longitudinal propagation velocity, as an index, efficient material selection in accordance with the desired vibration isolating effect is performed. Can be performed.

In the present invention, the impedance Z (kg / s · m ² ) obtained from the product of the density D (kg / m ³ ) and the longitudinal wave propagation velocity V (m / s) is set to 2000 to 5000 (kg / m ³ ).
Since a polyethylene foam material within the range of s · m ² ) is used as the vibration isolating layer, the propagation of subway running vibration to the underground structure can be reduced more effectively than before.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a plan sectional view showing a mounting state of a vibration-proof rubber.

FIG. 3 is a cross-sectional view showing one embodiment of the present invention.

FIG. 4 is a plan view showing the arrangement of test specimens in a test for verifying the effectiveness of the present invention.

5 (a) and 5 (b) are cross-sectional views showing the configuration of the test specimen shown in FIG.

6 (a) and 6 (b) are cross-sectional views showing the configuration of the test body shown in FIG.

FIG. 7 is a graph showing an anti-vibration effect obtained by verifying the effectiveness of the present invention with a test body using a subway as an actual vibration source.

FIG. 8 is a sectional view showing one embodiment of the present invention.

FIG. 9 is a cross-sectional view showing the installation state of the vibration-proof rubber and the vibration-proof layer when cut along the line XX in FIG.

FIG. 10 is a graph showing the effect of reducing vibration propagation from a subway on the first basement floor of an underground structure to which the present invention is applied.

FIG. 11 is a graph showing the effect of reducing vibration propagation from a subway at the second basement floor of an underground structure to which the present invention is applied.

FIG. 12 is a graph showing the effect of reducing vibration propagation from a subway at the third basement floor of an underground structure to which the present invention is applied.

FIG. 13 is a cross-sectional view showing a conventional anti-vibration structure of an underground structure.

FIG. 14 is a cross-sectional view showing a conventional anti-vibration structure of an underground structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Floor slab 2 Projection part 3 Outer wall 4 Foam polystyrene board 5 Anti-vibration rubber 10 Floor slab 10a Floor slab 10b Floor slab 11 Projection part 11a Projection part 11b Projection part 20 Anti-vibration rubber 20a Anti-vibration rubber 20b Anti-vibration rubber Reference Signs List 30 outer wall 30a outer wall 30b outer wall 40 anti-vibration layer 40a anti-vibration layer 40b anti-vibration layer 50 mountain retaining wall 100 specimen 100a specimen 100b specimen 100c specimen 100d specimen 110 concrete base 120 polyethylene foam 130 concrete block 140 vibration isolation Rubber 150 Base 160 Base A Mountain stop B Subway l Length m Length n Length

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yukio Urushido 4-6-115 Sendagaya, Shibuya-ku, Tokyo Inside Fujita Co., Ltd. (72) Inventor Tomoki Kotani 4-6-1-15 Sendagaya, Shibuya-ku, Tokyo Inside Fujita Co., Ltd. (72) Takao Sonobe, Inventor 4-6-1-15 Sendagaya, Shibuya-ku, Tokyo Inside Fujita Co., Ltd. (72) Yasuo Suzuki 4-6-1, Sendagaya, Shibuya-ku, Tokyo Fujita Co., Ltd. (72) Inventor Shinichi Yamao 4-6-15 Sendagaya, Shibuya-ku, Tokyo Inside Fujita Co., Ltd. (72) Inventor Hiroyasu Konan 4-6-115 Sendagaya, Shibuya-ku, Tokyo Fujita Co., Ltd. (72 Inventor Ken Yamamoto 12-54, Nakata-shinden, Furukawa-shi, Ibaraki Prefecture (72) Inventor Hisao Tezuka 2237-10 Shimookamoto, Kawachi-cho, Kawachi-gun, Tochigi Prefecture (72) Inventor Sadao Nomoto Kanagawa Kamakura Okamoto 2-9-8

Claims (5)

[Claims] 1. An anti-vibration structure for an underground structure provided in the ground of a building, comprising: a projecting portion provided on a periphery of a floor slab of the underground structure; A rubber cushion provided laterally in accordance with the height and length of the protruding portion; an outer wall provided below the floor slab; and A vibration-proof structure for an underground structure, characterized by having a vibration-proof layer made of polyethylene foam material. 2. The vibration damping structure for an underground structure according to claim 1, wherein the projecting portions are provided on the periphery of a floor slab on each basement floor of the underground structure, respectively, and Between the mounting portion and the height and length of the protruding portion is provided with a vibration isolating rubber in the lateral direction, respectively, the mountain retaining side, and provided between the floor slab of the upper and lower basement floor An anti-vibration structure for an underground structure, wherein an anti-vibration layer made of a polyethylene foam material is provided between the outer wall and the anti-vibration rubber at the top and bottom. 3. An anti-vibration structure for an underground structure according to claim 2, wherein the anti-vibration rubber provided between the protruding portion of the peripheral edge of the floor slab of each basement floor and the mountain retaining side is provided with the anti-vibration rubber. An anti-vibration structure for an underground structure, characterized in that the deeper the underground where the rubber is provided, the higher its height is set in accordance with the load from above. 4. The vibration isolating structure for an underground structure according to claim 1, wherein the polyethylene foam material has a density D (kg / m ³ ) and a longitudinal wave propagation velocity V (m). / S), and an impedance Z (kg / s · m ² ) obtained by multiplying the underground structure is selected as an index within a set range corresponding to a desired amount of vibration reduction. Anti-vibration structure. 5. An anti-vibration structure for an underground structure according to claim 4, wherein said polyethylene foam has an impedance Z.
(Kg / s · m ² ) is 2000 to 5000 (kg / s
A vibration damping structure for an underground structure which is selected within the set range of m ² ) to reduce the propagation of subway running vibration to the underground structure.