JP3621052B2 - Sound barrier - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a soundproof wall installed on a railway track, a road or the like, and particularly relates to a soundproof wall having excellent soundproof performance.
[0002]
[Prior art]
Conventionally, relatively heavy materials such as concrete have been used for soundproof walls installed on railway tracks, roads, etc., in order to ensure soundproof performance. In particular, most of the noise barriers installed on railway viaducts, which generate not only noise but also large vibrations, are made of concrete or concrete panels attached to steel columns.
[0003]
Recently, mainly from the viewpoint of improving workability, the demand for light-weight soundproof walls has been increasing, and soundproof walls using light-weight materials such as plastics as well as concrete are being developed. However, particularly for soundproof walls installed on railway viaducts, etc., vibrations that occur when vehicles pass through are prone to resonate if the soundproof wall is light, and the soundproof performance may be reduced by the resonance. It was difficult to adopt a soundproof wall.
[0004]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a soundproof wall that can adopt a light-weight configuration without deteriorating soundproof performance, particularly in places with large vibrations such as railway viaducts.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, a soundproof wall according to the present invention is a soundproof wall installed on a railway track, road, etc., and at least as a part constituting the soundproof wall in a soundproof wall installed on a railway track, road, etc. and a mounting portion of the sound insulation part and building skeleton, and any components of the sound barrier, except for soundproofing unit, characterized in that the lower portion of the elastic modulus or rigid there than other portions Consists of things.
[0006]
The part having a lower elastic modulus or rigidity than the other parts is provided as a part of the soundproof wall constituting part in the soundproof wall, and is a normal vibration isolation provided between the soundproof wall and the building frame. It is different from a vibration isolating member such as rubber or a vibration absorbing member. That is, since the soundproof wall according to the present invention is provided outdoors with respect to railroad tracks, roads, etc., if a normal mere anti-vibration rubber or the like is used, it is exposed to rain or sunlight and has a sufficiently long service life due to aging Therefore, a part having a lower elastic modulus or rigidity than the other part is provided as a part of the soundproof wall constituting part that can ensure a sufficiently long service life.
[0007]
The portion having a lower elastic modulus or rigidity than the other portions described above can be configured as a part of a column body that supports the soundproof portion or a mounting portion that fixes the column body to the building frame. In addition, the part having a lower elastic modulus or rigidity than the other part may be provided between the pillar body that supports the soundproofing part and the attachment part that fixes the pillar body to the building frame .
[0008]
It is preferable that the portion having a lower elastic modulus or rigidity than the other portions has the following characteristics. For example, when a load of 10 times the total weight of the part on the soundproofing part side is applied to a part having a lower elastic modulus or rigidity than the other part, the elastic modulus or the other part It is preferable that the maximum deformation amount of the portion having low rigidity is 1 mm or more.
[0009]
That is, if the soundproof wall itself is considered as a mass point supported by a spring, the natural frequency f of the mass point spring system is
f = 1 / 2π × √ (K / M)
K: Spring constant M: Mass. Than this,
K = (2πf) ² × M
Thus, if the spring constant K is made smaller (softer) than the value obtained by the above equation, it is considered that vibrations with a frequency exceeding f are not easily transmitted to the mass point. And if f is 50 Hz, which does not disturb human ears,
K = 100,000 x M
It becomes. Here, when the unit is read from SI system to kg, mm,
100,000 × M (N / m) = 10 × M (kgf / mm)
This corresponds to a spring that deforms 1 mm when a load 10 times its own weight is applied. Therefore, as described above, when a load of 10 times the total weight of the part on the soundproofing part side is applied to the part having a lower elastic modulus or rigidity than the other part, the elastic modulus or rigidity is higher than that of the other part. When the maximum deformation amount of the low portion is 1 mm or more, an excellent vibration isolation effect is obtained, and thereby an excellent sound insulation effect is obtained.
[0010]
More specifically, a portion having a lower elastic modulus or rigidity than other portions can be formed of a single metal plate having a thickness of 6 mm or less. Further, the part having a lower elastic modulus or rigidity than the other part can be formed of a fiber-reinforced plastic single plate having a thickness of 10 mm or less.
[0011]
That is, a portion having a lower elastic modulus or rigidity than other portions can be formed by various methods. For example, this part can be configured by using a softer material than other parts (for example, aluminum for steel, fiber reinforced plastic (FRP) for metal, rubber for FRP, etc.). Moreover, this part can also be comprised by making it softer in shape than other parts (for example, making thickness thin, making a sandwich structure into a single plate). In the case of FRP, by changing the orientation of the reinforcing fiber (for example, changing the 0 ° orientation to 45 ° orientation) or changing the content of the reinforcing fiber, the elastic modulus or rigidity is higher than that of other parts. Can be lowered. Any of these methods can be used. In particular, when this part is made of FRP, the rigidity of the reinforcing fiber can be reduced by devising the orientation of the reinforcing fiber, so it is ideal for soundproof walls that must withstand wind pressure. There is a high possibility of realizing something.
[0012]
The soundproof part in the present invention is not particularly limited, and may be any of concrete, metal, or fiber reinforced plastic. When importance is attached to the light weight of the entire soundproof wall, it is particularly preferable to use a fiber reinforced plastic. For example, it is preferable that at least the soundproofing part is composed of a core material and a skin material made of fiber reinforced plastic located on both sides of the core material.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Below, desirable embodiment of the soundproof wall of the present invention is described based on an example.
[0014]
【Example】
Example 1
1 and 2 are perspective views of a soundproof wall according to Embodiment 1 of the present invention. FIG. 1 is a view seen from the front side, and FIG. 2 is a view seen from the back side. In actual installation, a plurality of soundproof walls 1 shown in the figure are provided side by side in the horizontal direction and the vertical direction to form a continuous soundproof wall. Which side is used as the vehicle traffic side depends on the application and installation location, but in the case of a railway vehicle, the back side is usually the vehicle traffic side.
[0015]
In the present embodiment, the soundproof wall 1 includes a soundproof portion 2, a column body 3, and a mounting portion 4, which are integrally formed. In the present embodiment, the attachment portion 4 is provided below the soundproof portion 2. However, depending on the installation location, it may be the left and right or the upper part of the soundproof unit 2, and such a mode is also included in the present invention.
[0016]
The soundproofing part 2 is formed in a planar shape for achieving prevention of noise diffusion and prevention of falling of a track maintenance worker, and is formed in a rectangular shape so that a plurality of soundproofing parts 2 can be connected. As shown in FIG. 1, the cross-sectional structure is composed of a core material 2d located at the center, skin materials 2a and 2b located on both sides thereof, and ribs 2c connecting the skin materials 2a and 2b, which are integrally formed. Has been. The external dimensions of the soundproofing part 2 depend on the application, but when used as a railing in a railway viaduct, the vertical dimension H is 500 to 3000 mm, preferably 1000 to 2000 mm, and the horizontal dimension (width) W is 25 m per unit. (When it is more than that, it is difficult to transport in dimension.) When connecting relatively small ones, each range in which the lateral dimension W is 500 to 2000 mm and the thickness T is 10 to 100 mm. It is preferable that it is within the range from the viewpoint of preventing the diffusion of noise and preventing the maintenance worker from falling. When the lateral dimension W is relatively large, at least a part of the soundproof portion 2 can be formed in a curved portion that is curved along a curve such as a viaduct, and the soundproof wall can be configured to have a curved portion.
[0017]
The core material 2d serves as a spacer for securing bending rigidity as well as soundproofing, and as the material thereof, it is preferable to use a lightweight material such as a hard urethane foam of 30 times foam, for example. Alternatively, a honeycomb material may be used. In addition, a material for adding a special function such as selecting a material having a high vibration damping effect in order to enhance the soundproofing effect may be used. The preferred thickness _{t 1} of the core 2d is in the range of 8～98Mm, more preferably in the range of 30 to 70 mm.
[0018]
Skin material 2a, 2b comprises the outer surface of the soundproof wall of this invention, and is comprised with the fiber reinforced plastics. Examples of the reinforcing fiber include glass fiber, carbon fiber, and aramid fiber. The fineness of the reinforcing fiber is preferably in the range of 100 to 2000 dtex, but 200 to 1000 dtex is more preferable from the viewpoint of preventing the fall of small pieces. Examples of the matrix resin include an epoxy resin, an unsaturated polyester resin, and a vinyl ester resin. From the viewpoint of preventing small pieces from dropping, it is preferable to use an epoxy resin. The volume content Vf of the reinforcing fiber is preferably 15 to 60%, more preferably 30 to 50%. Further, the total thickness T of the soundproof unit 2, the ratio T of the thickness _{t 2} of the skin material 2a, 2b: The _{t 2,} 5: 1 to 50: is preferably in the 1 range. Skins 2a beyond this range, the thickness t ₂ of 2b becomes thicker, lighter is impaired is a feature of the sound barrier of the present invention. On the other hand, if the skin materials 2a and 2b are thinner than this range, the strength against wind pressure, which is necessary for the soundproof wall, mainly during typhoons, may not be sufficiently developed. Especially in order to ensure light weight except the columnar body 3 and the attachment portion 4, the weight per unit area of the sound insulation part 2 is preferably in the range of 10~60kg / m ^2.
[0019]
Further, when importance is attached to flame retardancy, it is also possible to use a highly flame retardant resin, for example, a phenol resin, as a matrix resin of the fiber reinforced plastic forming the skin materials 2a and 2b.
[0020]
The column 3 supports both sides of the soundproofing part 2, and in this embodiment, the structure is composed of a core material 3b at the center and a skin material 3a made of a fiber reinforced plastic surrounding the same as the soundproofing part described above. It is configured. In the present embodiment, the columnar body 3 is formed such that its outer shape tapers along the vertical direction of the soundproofing part 2 and is integrally formed with the soundproofing part 2. The column body 3 is provided as necessary when the soundproof portion 2 requires strength. For example, in order to withstand considerable wind pressure as in the typhoon season, the skin material 2a, 2b of the soundproof portion 2 is provided. It is desirable to include at least 5% or more of a layer made of carbon fiber reinforced plastic in a thickness ratio with respect to the skin material. For further strengthening, it is desirable that the skin material 3a of the column 3 also includes a layer made of carbon fiber reinforced plastic at least in a thickness ratio of 5% or more. In addition, it is necessary to prevent the soundproof wall from bending and resonating with respect to wind pressure. In this case, the types and amounts of the reinforcing fibers of the skin materials 2a and 2b and the skin material 3a in the soundproof portion and the column body portion, and the type of matrix resin By designing appropriately, the bending rigidity of both members can be increased.
[0021]
By adopting such a structure, it is only necessary to give the soundproof part 2 strength and rigidity only in the width direction between the pillars 3 and to give the pillar part strength and rigidity only in the vertical direction. Design that uses material anisotropy peculiar to fiber reinforced plastics without using wasteful materials in terms of strength and rigidity becomes possible, and further weight reduction can be realized.
[0022]
In this way, since the soundproofing part 2 as a face body has to have strength and rigidity mainly in the lateral (width) direction, the fiber reinforced plastic skin materials 2a and 2b of the soundproofing part 2 are, for example, It is preferable to include continuous reinforcing fibers extending in a direction having an inclination of 60 ° or more with respect to the extending direction. Also, with respect to the rib 2c, the soundproof portion 2 as a plane body may be given strength and rigidity mainly in the lateral (width) direction, so that at least a part of the rib 2c is, for example, in the extending direction of the column 3 It is preferable to extend in a direction having an inclination of 60 ° or more.
[0023]
In this embodiment, the attachment portion 4 is formed in a triangular shape, and is fixed to the building housing 6 with a chemical anchor 5a, a metal plate 5b, a nut 5c, etc. The fixing means, shape, material, dimensions, and the like are not limited to the metal surface or the like because it is only required to be fixed to an appropriate fastener such as a bolt or nut.
[0024]
In such a soundproof wall 1 according to the present embodiment, first, the weight can be reduced. That is, since the soundproof part 2 and the column 3 are made of a skin material made of fiber reinforced plastic, the specific strength is higher than that of a general metal such as concrete or iron, and the soundproofing panel 2 is used as a soundproof wall panel. The required strength can be achieved and the weight can be significantly reduced, and installation at high places can be facilitated without the use of dedicated erection devices such as heavy machinery.
[0025]
In the present embodiment, the portion 7 having a lower elastic modulus or rigidity than the other portion provided between the soundproof portion 2 and the building housing 6 in the soundproof wall 1 is an attachment portion made of fiber reinforced plastic. insertion portion 4 of the anchor 5a, that is, is formed as part of the mounting portion 4. In this embodiment, the portion 7 having a lower elastic modulus or rigidity than the other portions is configured as a single plate made of glass fiber reinforced plastic having a thickness of 6 mm.
[0026]
In order for the portion 7 having a lower elastic modulus or rigidity than the other portions to effectively work to prevent vibrations and noise generation due to vibrations, that is, to effectively absorb vibrations or to make vibration propagation paths effective. In order to exhibit a low elastic modulus or rigidity, it must be fixed so as to allow deformation. In order to confirm this and the effect of the portion 7 having a lower elastic modulus or rigidity than the other portions, the following test was performed.
[0027]
As shown in FIG. 3, the soundproof wall 1 is fixed on the vibration table 11 of the vibration exciter, and vibration transmitted to the soundproof wall 1 during vibration is attached near the upper end of the soundproof portion 2. The acceleration pickup 12 measured the acceleration (G) with respect to the vibration frequency (Hz).
[0028]
First, as shown in FIG. 4 (FIG. 4 shows a soundproof wall portion when the soundproof wall 1 is viewed from the direction of arrow A in FIG. 2), the elastic modulus or rigidity is lower than the other parts of the soundproof wall 1. When the portion 7 was completely brought into close contact with the upper surface of the vibration table 11, the acceleration (G) characteristic with respect to the vibration frequency (Hz) was as shown in FIG. In this fixing method, the portion 7 having a lower modulus of elasticity or rigidity than the other portions is completely fixed in close contact with the upper surface of the vibration table 11, so that the original deformation of the portion 7 is not allowed, and therefore the present invention The characteristic of the weak elastic modulus or rigidity of the portion 7 intended in (1) is not exhibited. In this case, as shown in FIG. 5, the lightweight soundproof wall 1 resonates in various frequency ranges, and has several resonance points in the range of 200 Hz to 300 Hz, and exhibits an excellent soundproofing effect. It turns out that it is difficult to do.
[0029]
Next, as shown in FIG. 6, a portion 7 having a lower elastic modulus or rigidity than other portions of the soundproof wall 1 is fixed in a state where it is floated from the upper surface of the vibration table 11 with a spacer 13 interposed therebetween. When the deformation of 7 was allowed and the low elastic modulus or rigidity could be expressed, the characteristics of acceleration (G) with respect to the vibration frequency (Hz) were as shown in FIG. In this case, as shown in FIG. 7, even if the soundproof wall 1 is light, vibration from the vibration table 11 is effectively absorbed or blocked by the portion 7 having a lower elastic modulus or rigidity than the other portions. It can be seen that the occurrence of resonance is almost completely prevented, and the vibration in the soundproof portion 2 is suppressed to a very small level. That is, the presence of such a portion 7 having a lower elastic modulus or rigidity than the other portions in the soundproof wall 1 allows the resonance to be efficiently suppressed even with the light-weighted soundproof wall 1, and a desired soundproof effect. It can be seen that it can be expressed.
[0030]
As described above, in the present invention, the path from the building housing to the soundproofing part in the soundproofing wall has a part having a lower elastic modulus or rigidity than other parts, so that the occurrence of resonance is very effectively performed. As a result, it is possible to cause the soundproof portion to exhibit the desired performance designed in design.
[0031]
Example 2
8 to 12 show a soundproof wall according to Example 2 of the present invention and a test using the soundproof wall. FIG. 8 shows one soundproof wall 21, and in this embodiment, the soundproof portion 22 is configured as a flat panel, and the soundproof portion 22 is as shown in FIG. It has a sandwich structure of a core material and a skin material located on both sides of the core material. A metal column 23, which is a column made of SUS pipe having a thickness of 2 mm in this embodiment, is provided integrally with the soundproof unit 22. The column body 23 extends to the lower side of the soundproof portion 22, and this extended portion is configured as a mounting portion 24 for the building frame. When the rib is provided in the soundproof portion 22, it is preferably extended in the direction 26 having an inclination of 60 ° or more with respect to the extending direction 25 of the column body 23. Moreover, it is preferable that the fiber reinforced plastic skin material of the soundproof portion 22 includes continuous reinforcing fibers extending in a direction having an inclination of 60 ° or more with respect to the extending direction 25 of the column body 23.
[0032]
As shown in FIG. 9, a plurality of such soundproof walls 21 are connected as soundproof walls of the railway viaduct 27. Anchor bolts 28 provided on the side surface of the viaduct 27 are used to fix the side surface of the viaduct 27 with the nut 30 in a state where the attachment portion 24 is floated with a spacer 29 interposed as shown in FIGS. Further, a cover 31 that covers the side surface of the viaduct 27 is provided on the outer surface side of the mounting portion 24, and is fixed by anchor bolts 32 and nuts 33. A ballast 35 is laid on the railway side of the trough portion 34 of the viaduct 27. However, since a space is formed between the trough portion 34 on the opposite side and the soundproof wall 21, this space is used for track maintenance work and the like. A suitable filling block 36 is interposed in order to fill the space.
[0033]
In the soundproof wall 21 having such a configuration, as shown in FIGS. 9 and 11, the column body 23 made of SUS pipe having a wall thickness of 2 mm is fixed in a state of being floated with respect to the side surface of the viaduct 27. As shown by the arrows in FIG. 11, deformation of the viaduct 27 side portion of the columnar body 23 made of a thin SUS plate is allowed, and this portion has an elastic modulus or It becomes the part 37 with low rigidity. The presence of a portion 37 having a lower elastic modulus or rigidity than the other portions between the viaduct 27 and the soundproofing portion 22 makes vibrations of the viaduct 27 very difficult to be transmitted to the soundproofing portion 22. The intended desired soundproofing effect is exhibited well.
[0034]
In order to confirm this effect, as shown in FIG. 12, after removing the existing soundproof wall made of concrete block, the height of the top of the soundproof wall 21 is 6 m from the side road 41. And 2 m from the center of the railway, near the private house 42, on the side road 41, at a distance of 4 m from the installation position of the soundproof wall 21 and at a position 1 m above the ground, the noise is generated by the microphone 43. Level was measured. As a result, a measurement value of 70 dB improved by 2 dB was obtained with respect to the noise level of 72 dB before the concrete block noise barrier was removed. Incidentally, it is generally considered very difficult to improve the noise level by 2 dB.
[0035]
Example 3 (design example)
Although an actual test was not performed, the soundproof wall according to the present invention can be configured as shown in FIG. That is, as compared with the structure shown in FIG. 11, a stepped anchor bolt 54 extending from the building housing 51 to the plate body portion 53 located on the anti-building housing side of the column 52 of the soundproof wall is provided. Can be fixed using a nut 55. By configuring the plate body portion 53 to be a portion having a lower elastic modulus or rigidity than other portions, which is referred to in the present invention, it is possible to obtain the same operations and effects as shown in FIG.
[0036]
【The invention's effect】
As described above, according to the soundproof wall of the present invention, the presence of a portion having a lower elastic modulus or rigidity than the other portions in the soundproof wall can appropriately prevent vibration from a railway viaduct or the like. In particular, it is possible to achieve excellent soundproofing performance even with a light-weighted soundproofing wall even at locations with large vibrations such as railway viaducts.
[Brief description of the drawings]
FIG. 1 is a perspective view of a soundproof wall according to Embodiment 1 of the present invention when viewed from the front.
FIG. 2 is a perspective view of the soundproof wall of FIG. 1 when viewed from the back side.
FIG. 3 is a perspective view showing a test state in which the soundproof wall of FIG. 1 is fixed on a vibration table.
4 is a partial cross-sectional view of the soundproof wall as viewed from the direction A in FIG. 2, showing a state in which the soundproof wall is directly fixed on the vibration table in the test of FIG.
FIG. 5 is a characteristic diagram showing a test result in the state of FIG.
6 is a partial cross-sectional view of the soundproof wall as viewed from the direction A in FIG. 2, showing a state in which the soundproof wall is floated by a spacer and fixed on the vibration table in the test of FIG.
7 is a characteristic diagram showing a test result in the state of FIG. 6. FIG.
FIG. 8 is a perspective view of a soundproof wall according to Embodiment 2 of the present invention.
9 is a cross-sectional view showing a state in which the soundproof wall of FIG. 8 is attached to a railway viaduct.
10 is an exploded perspective view showing a method of attaching the column body part in FIG. 9. FIG.
11 is a cross-sectional view of a portion attached by the attachment method of FIG.
12 is a schematic sectional view showing a state of a test in Example 2. FIG.
FIG. 13 is a partial cross-sectional view of a soundproof wall according to Embodiment 3 of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Soundproof wall 2 Soundproof part 2a, 2b Skin material 2c Rib 2d Core material 3 Column (part)
3a Column body skin material 3b Column body core material 4 Mounting portion 5a Chemical anchor 5b Metal plate 5c Nut 6 Building housing 7 Part having lower elastic modulus or rigidity than other parts 11 Excitation table 12 Acceleration pickup 13 Spacer 21 Soundproof wall 22 Soundproof portion 23 Column body 24 Mounting portion 27 Viaduct 28 Anchor bolt 29 Spacer 30 Nut 31 Cover 32 Anchor bolt 33 Nut 34 Trough portion 35 Ballast 36 Filling block 37 Portion 41 having lower elastic modulus or rigidity than other portions 41 Side road 42 Private house 43 Microphone 51 Building housing 52 Soundproof wall pillar 53 Plate part 54 as a part having lower elastic modulus or rigidity than other parts Stepped anchor bolt 55 Nut

Claims (7)

In a soundproof wall installed on a railway track, road, etc., it has at least a soundproof part and a mounting part to a building frame as a part constituting the soundproof wall , and any of the soundproof wall constituent parts excluding the soundproof part , soundproof walls, wherein a lower portion of the elastic modulus or rigid there than other portions. 2. The soundproofing according to claim 1, wherein the part having a lower elastic modulus or rigidity than the other part is a column body that supports the soundproofing part or a part of an attachment part that fixes the pillar body to the building frame. wall. The portion having a lower elastic modulus or rigidity than other portions is provided between a column body that supports the soundproofing portion and an attachment portion that fixes the column body to the building frame. Sound barrier as described in When a load of 10 times the total weight of the part on the soundproofing part side is applied to a part having a lower elastic modulus or rigidity than the other part, the elastic modulus or rigidity is higher than that of the other part. The soundproof wall according to any one of claims 1 to 3, wherein a maximum deformation amount of the low portion is 1 mm or more . The soundproof wall according to any one of claims 1 to 4, wherein a portion having a lower modulus of elasticity or rigidity than other portions is formed of a single metal plate having a thickness of 6 mm or less . The soundproof wall according to any one of claims 1 to 4, wherein a portion having a lower modulus of elasticity or rigidity than other portions is formed of a single plate made of fiber-reinforced plastic having a thickness of 10 mm or less . The soundproof wall according to any one of claims 1 to 6 , wherein at least the soundproofing part is composed of a core material and a skin material made of fiber reinforced plastic located on both sides of the core material .

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