JP4621828B2 - Sound barrier - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a soundproof wall installed on the side of a highway or a railway overpass as a soundproofing measure for a vehicle.
[0002]
[Prior art]
For local noise barriers against noise sources such as noise barriers along railway lines, road side noise barriers, and multi-story parking lots, sound absorbing plates and sound insulating plates are fixed to concrete walls that are conventionally cast in place with fasteners. And build. At this time, in order to form an air layer between the sound absorbing plate (or the sound insulating plate) and the concrete wall, a spacing member is often interposed between the two.
When such a soundproof wall is installed along a railway line, for example, a sound absorbing plate or the like occupies a limited internal air section, so it is necessary to secure a space for mounting in advance. In addition, there is a problem in that the workability is poor because the spacing member, the clasp, etc. are required even when mounting.
[0003]
The present inventors have previously proposed a soundproof wall structure comprising a sound absorbing panel obtained by combining and integrating a weir plate and a porous sound absorbing plate through an air layer, and a concrete wall in contact with the weir plate. (JP 2000-8331 A). The soundproof wall according to the present invention uses the sound absorbing panel as a concrete casting mold and uses the concrete wall as a sound insulating wall, so that removal work in the mold work is not required and labor saving can be achieved. It cannot be denied that advanced technology is required to satisfy construction accuracy during installation.
[0004]
[Problems to be solved by the invention]
The present invention provides a soundproof wall in which a porous sound absorbing plate is attached to a precast concrete wall, and an object thereof is to provide a soundproof wall excellent in noise reduction effect and workability in construction. Is.
[0005]
[Means for Solving the Problems]
The soundproof wall of the present invention is a soundproof wall having a porous sound absorbing plate attached to a precast concrete wall made of fiber reinforced concrete, and the concrete wall surface has a vertical rib and a recess as a back air layer. To solve the problem.
The sound absorbing plate is preferably fixed by screwing a bolt through a shape steel or a flat steel into an insert embedded in the concrete wall in advance.
It is preferable that a lower end portion of the concave portion covered with the sound absorbing plate is opened.
It is preferable that the sound absorbing plate is obtained by curing an inorganic granular material and a fibrous filler added as necessary with a binder.
[0006]
[Action]
The plurality of vertical ribs formed on the inner wall surface of the concrete wall reinforce the strength of the thin concrete wall and at the same time secure a back air layer. Thus, the generated noise is effectively reduced by the sound absorbing plate, the sound insulating concrete wall, and the air layer sandwiched therebetween.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, as a preferred embodiment of the present invention, a soundproof wall installed on a road or a railway overpass will be described.
FIG. 1 is a partial perspective view of a soundproof wall 10 erected on an elevated foundation 8, showing the soundproof wall 10 constructed by attaching a sound absorbing plate 20 to the inner wall surface of a concrete wall 12. Yes. The concrete walls 12, 12... Are made of precast and fixed to the elevated foundation 8 by anchor bolts 9, and these are continuously erected to construct a side noise barrier along the road or railway elevated. Is done.
[0008]
The concrete wall 12 is made of fiber reinforced concrete. In the present invention, fiber reinforced concrete is used in order to improve the mechanical properties of cement concrete and reduce the weight of the member. Examples of fibers suitable as the reinforcing material to be mixed include synthetic fibers such as vinylon fibers, aramid fibers, and polyethylene fibers, carbon fibers, and glass fibers. By using these reinforcing materials, the precast concrete wall 12 can be thinned without using a rusting material.
[0009]
On the inner wall surface of the concrete wall 12, a recess 14 is formed as an air layer behind the sound absorbing plate 20. The recess 14 is provided on the entire inner wall surface and preferably has a thickness of about 5 to 20 cm in terms of noise reduction effect.
As shown in FIG. 2, a plurality of vertical ribs 16, 16 are provided on the inner wall surface of the concrete wall 12 in the vertical direction. The vertical ribs 16 and 16 have the original purpose of maintaining the strength of the thin concrete wall 12 and the role of supporting the sound absorbing plate 20 while ensuring a back air layer on the wall surface of the concrete wall 12. Therefore, there is no restriction on the shape and the number of strips of the vertical ribs 16 and 16 as long as these functions are satisfied.
[0010]
The sound absorbing plate 20 of the present invention is made of a porous material in which voids are continuously formed, and has a structure in which sound is easily absorbed. As the main material of the sound-absorbing plate, inorganic granular materials are used, and foamed granular materials of natural stone such as obsidian, pearl stone, antifossil, and shirasu, or foamed granular materials of glass and various ceramics are preferable. Use. The particle size of the inorganic granular material is preferably about 0.1 to 2 mm.
[0011]
In the present invention, in order to increase the strength of the sound absorbing plate 20, it is desirable to reinforce the sound absorbing plate by mixing a filler in the sound absorbing material. The filler is preferably a chopped strand, matte or net fiber, such as an inorganic fiber such as glass fiber, rock wool or carbon fiber, or an organic synthetic fiber such as vinylon or polyester. Things can be used. Moreover, what made the prepreg by impregnating a thermosetting resin, such as a phenol resin, a polyester resin, an epoxy resin, a melamine resin, and making it semi-harden a fiber can also be used suitably. Note that the portion reinforced with the filler may be in any position in the vicinity of or inside the surface of the sound absorbing plate, or may have any structure of a single layer or two or more layers.
[0012]
The sound-absorbing plate 20 is preferably formed and cured with a binder from the inorganic particulate matter and a fibrous filler added as necessary.
As the binder, any of organic and inorganic binders can be used. In producing a sound-absorbing material by adhering the inorganic particulates in a spot-like manner, the curing temperature is in the range of 80 to 200 ° C. It is preferable to use a thermosetting resin-based binder in the above.
Examples of such a synthetic resin include a phenol resin, an epoxy resin, a melamine resin, a urea resin, and a lignin resin, and a phenol resin is particularly preferable. In the case of a phenol resin, the mixing ratio with respect to the inorganic particulates is preferably 1.5 to 25% by weight, particularly preferably 5.0 to 15% by weight. If it is less than 1.5% by weight, the granular materials or the granular materials and the filler cannot be firmly bonded, and the strength of the sound absorbing material is lowered. On the other hand, if it exceeds 25% by weight, voids between the granular materials are filled, and a porous structure suitable for the sound absorbing material cannot be formed.
[0013]
In order to manufacture the sound-absorbing plate 20, the inorganic particulate matter, the filler and the binder may be simply mixed, or the surface of the inorganic particulate matter is previously coated with the binder, and then the filler and the binder to be added if necessary. May be mixed. Next, these mixtures or granular materials are put into a mold or the like, and a lubricant is mixed as desired, and heated and pressurized to form by a dry process. Of course, you may manufacture by a wet manufacturing method.
The thus obtained sound absorbing material has a porosity of 5 to 75%, preferably about 10 to 50%. The porosity is determined depending on the types and blending ratios of inorganic particulates, filler and binder, or press. The pressure and temperature conditions can be adjusted by appropriately selecting the production method.
[0014]
Next, a method for attaching the sound absorbing plate 20 to the concrete wall 12 will be described with reference to FIG.
FIG. 3 (1) shows the state of attachment of the sound absorbing plate 20 in the vicinity of the connecting portion between the adjacent concrete walls 12 and 12, and reference numeral 18 denotes a bowl-shaped packing disposed in the connecting portion.
Inserts 22 are embedded in the precast concrete wall 12 in advance at the manufacturing stage, and the sound absorbing plate 20 is attached to the concrete wall 12 by screwing bolts 26 into the concrete wall 12 via the shape steel 24. In the present embodiment, a Z-shaped steel is used as the shape steel 24, but such an attachment method is preferable as an attachment method for both the left and right sides and the lower side of the rectangular sound absorbing plate 20.
[0015]
FIG. 3 (2) is a cross-sectional view showing the state of attachment of the upper side of the sound absorbing plate 20 at the top of the concrete wall 12, and the sound absorbing plate 20 is bolted with a chevron shaped steel 24. FIG. 3 (3) shows a state in which the upper and lower two-stage sound absorbing plates 20, 20 are attached simultaneously at the middle portion in the vertical direction of the concrete wall 12. Is fixed.
When attaching the sound absorbing plate 20 to the concrete wall 12, it is preferable to use the shape steel 24 so that the shape and structure of the concrete wall 12 are not complicated, but if necessary, flat steel should be used. You can also. In any case, since the sound absorbing plate 20 is bolted to the concrete wall 12 in the present invention, maintenance work such as replacement is extremely easy. It should be noted that a shock absorber (not shown), for example, a foamed urethane tape having a thickness of about 5 mm, is sandwiched between the sound absorbing plate 20 and the concrete wall 12, thereby allowing the sound absorbing plate 20 to be fluttered by an external force such as wind pressure. It can be suppressed as much as possible.
[0016]
As described above, the sound absorbing plate 20 is bolted to the four sides of the concrete wall 12 and the vertical ribs 16 so that the concave portion 14 of the concrete wall 12 is covered with the sound absorbing plate 20 to form a back air layer. , The lower end of the recess 14 is open. This is intended to promote the drainage and ventilation of rainwater so that moisture and moisture do not adversely affect the durability and sound absorption performance of the sound absorbing plate 20. Further, by opening the lower end of the recess 14 about several centimeters, it is possible to easily check the mounting bolts for the anchor bolts 9 on the concrete wall 12 that are necessary after the installation is completed.
[0017]
【Example】
In the viaduct 6 shown in a sectional view in FIG. 4, the sound reduction effect by the soundproof wall 10 was measured. The soundproof wall 10 has a sound absorbing plate 20 attached to the inner wall surface of the concrete wall 12 described above, and the noise level at the time of passing a train at various train speeds was measured at a measurement point M outside the soundproof wall 10. The results are shown in FIG. For comparison with this, the noise level was measured only with the concrete wall 12 from which the sound absorbing plate 20 was removed, and the result is shown by □ in FIG.
From the measurement results of both, the noise level of the soundproof wall 10 to which the sound absorbing plate 20 was attached was reduced by 3 dB to 5 dB, and a noise reduction effect was recognized.
[0018]
【The invention's effect】
The soundproof wall according to claim 1 has a recess and a vertical rib as a back air layer on the inner wall surface of the concrete wall, and the concrete wall is precast manufactured with fiber reinforced concrete, so that the sound absorbing plate and the concrete wall are integrated. A lightweight and thin soundproof wall structure can be realized. Moreover, since construction is possible without widening the entire construction space, it is excellent in workability.
Furthermore, since the soundproof wall surface has a smooth structure, there is no hindrance to traffic and work on the side of the wall surface, and the smooth surface is surface-treated or painted to improve the landscape and beauty. Has a side effect.
[0019]
According to the soundproof wall of the second aspect, it is possible to reduce the material cost and the construction cost without requiring an extra metal fitting such as a spacer. In addition, the sound absorbing plate is easy to install, and at the same time, it is easy to replace or change specifications even if it is damaged.
In the soundproof wall according to the third aspect, consideration is given to the durability and sound absorbing performance of the sound absorbing plate, and maintenance work such as replacement can be performed very easily.
The noise barrier according to claim 4 has a particularly remarkable noise reduction effect.
[Brief description of the drawings]
FIG. 1 is a partial perspective view of a soundproof wall of the present invention.
FIG. 2 is a front view of a precast concrete wall.
FIG. 3 is a cross-sectional view showing a state in which a sound absorbing plate is attached to a concrete wall.
FIG. 4 is a cross-sectional view of a viaduct that measures the sound reduction effect of a sound barrier.
FIG. 5 is a graph showing the measurement result of the noise level in the example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Soundproof wall 12 Concrete wall 14 Recessed part 16 Vertical rib 20 Sound absorption board 22 Insert 24 Shape steel 26 Bolt

Claims (3)

To face the pre-cast a concrete wall made of fiber reinforced concrete a sound barrier which is attached a porous sound-absorbing plate, the concrete walls have a recess as longitudinal ribs and back air layer, it is covered by the sound absorbing plate Further, a soundproof wall in which a lower end portion of the concave portion is opened .   The soundproof wall according to claim 1, wherein the sound absorbing plate is fixed by screwing a bolt through a shape steel or a flat steel into an insert embedded in the concrete wall in advance. The soundproof wall according to claim 1 or 2, wherein the sound absorbing plate is obtained by curing inorganic particulate matter and a fibrous filler added as necessary with a binder.

Images