JP4091836B2 - Noise barrier for railway - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a railway noise barrier.
[0002]
[Prior art]
As the sound barrier 20 for the Shinkansen, for example, as shown in FIGS. 6 and 7, a reverse L-type sound barrier with a top plate 21 attached to the upper part is often used. (For example, refer to Patent Document 1.) In FIGS. 6 and 7, reference numeral 22 denotes a soundproof side wall, and a sound absorbing material 22 a is attached to the inside of the soundproof side wall 22.
[0003]
[Patent Document 1]
JP-A-7-305310 (FIG. 4)
[0004]
[Problems to be solved by the invention]
By the way, it is necessary to improve the performance of the existing soundproof wall in order to reduce the noise along the line and to maintain the line along with the speed of the train.
Therefore, along with the attachment of the sound-absorbing material 22a to the sound-insulating side wall 22, measures for raising the height using the sound insulating plate 23 are taken. However, in order to raise the sound insulation plate 23 vertically to the outer end portion of the sound insulation side wall 22, it is necessary to sufficiently reinforce the sound insulation plate 23 in consideration of the influence of wind and the like. Since the work takes time and effort, the cost is increased, and the sound insulation plate 23 is easily damaged by wind and rain, so that maintenance is also troublesome.
[0005]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a railway soundproof wall that can reduce costs and does not require time and effort for maintenance.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 includes, as shown in FIGS. 1 to 3, for example, a soundproof side wall 3 extending along the track 4 to the side of the track 4, and the soundproofing. A soundproof wall for railways, comprising a soundproof top plate 7 that projects substantially horizontally from the upper end of the side wall 3 toward the track 4 side,
A sound absorbing material 10 is provided on the upper surface of the soundproofing top plate 7, and the sound absorbing material 10 is a raised portion in which the portion located on the base end portion of the soundproofing top plate 7 is raised higher than the other portions. It has the upper part 10a.
[0007]
Here, examples of the sound absorbing material include porous materials and fibrous materials such as glass wool, but are not limited thereto.
[0008]
According to the first aspect of the present invention, the rolling noise of the train (noise generated when the wheel travels on the rail) diffracts the front end portion (inner end portion) of the soundproof top plate. When it goes around the upper surface, a part of the sound is absorbed by the sound absorbing material and further diffracted and propagated at the base end of the sound absorbing material. Since the diffracted portion has a raised portion, noise can be reduced by the raised portion, and noise propagating to the region behind the soundproof side wall can be reduced.
In this way, by providing a sound-absorbing material having a raised portion on the top surface of the soundproofing plate, noise can be reduced and there is no need to raise the sound insulating plate vertically as in the conventional case. There is no need for reinforcement or maintenance, thus reducing costs.
Moreover, since the raised portion of the sound absorbing material is located on the base end portion of the soundproof top plate, the raised portion is located immediately above the soundproof side wall. Therefore, the raised portion can prevent the soundproof top plate from being bent downward, and can reduce the load on the soundproof side wall.
According to a second aspect of the present invention, in the railway soundproof wall according to the first aspect, the front end portion of the sound absorbing material extends to the lower surface of the soundproof top plate 7 so as to cover the front end portion of the soundproof top plate. It is characterized by existing.
According to the second aspect of the present invention, the front end portion of the sound absorbing material extends to the lower surface of the soundproof top plate so as to cover the front end portion of the soundproof top plate. The noise generated when traveling on the top is diffracted by the tip when the tip (inner end) of the soundproof top plate is diffracted, so that it propagates from the top to the region behind the soundproof side wall. Noise can be further reduced.
[0009]
The invention according to claim 3 is the noise barrier for railway according to claim 1 or 2 ,
The surface of the sound absorbing material 10 is covered with a thin film.
Here, the thin film is preferably formed of a material that does not pass dust, moisture, moisture, etc. and transmits sound waves. For example, a polyethylene film having a thickness of 30 μm or less is preferably used as such a material. Is done.
[0010]
According to the third aspect of the invention, since the surface of the sound absorbing material is covered with a thin film, it is possible to prevent dust, moisture, and moisture from adhering to the sound absorbing material, and thus the sound absorbing ability of the sound absorbing material can be easily achieved. Can be maintained.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
1 to 3 show a first embodiment.
In these drawings, reference numeral 1 indicates a viaduct for the Shinkansen. A soundproof side wall 3 is provided so as to extend along the track 4 at the overhanging portion 2 of the viaduct 1, that is, on the side of the track 4. The soundproof side wall 3 is made of cast-in-place reinforced concrete or PC (precast) plate, and a sound absorbing material 3a is adhered to the inner surface thereof, that is, the surface facing the track 4 side (see FIG. 2).
[0012]
Further, as shown in FIG. 2, pillars 5 made of H-shaped steel are erected on the inner side of the soundproof side wall 3 at predetermined intervals (for example, at intervals of 3 meters) in the longitudinal direction of the track 4. A support beam 6 made of H-shaped steel is supported on the upper end of 5 in a substantially horizontal state in a cantilever state.
[0013]
A plurality of soundproof top plates 7 projecting substantially horizontally from the upper end portion toward the track portion 4 are connected to the upper end portion of the soundproof side wall 3 in the longitudinal direction of the track 4. The soundproof top plate 7 is a PC (precast concrete) plate extending along the track 4 and is supported from below by the support beam 6. That is, as shown in FIG. 3, the support beams 6 are provided at a predetermined interval (for example, an interval of 3 meters) along the longitudinal direction of the track 4 (left and right direction in FIG. 3). The both ends of the soundproof top plate 7 are placed and fixed on the upper flanges 6a and 6a, so that they are supported by the support beams 6 and 6 from below. The soundproof top plate 7 is formed at a position lower than the window of the train traveling on the track 4 so as not to obstruct the view from the window.
[0014]
As shown in FIGS. 1 and 2, a plurality of sound absorbing materials 10 are provided on the upper surface of the soundproof top plate 7. This sound-absorbing material 10 is formed of a fiber molded body obtained by water-repellent treatment of polyester short fibers and has a raised portion 10a. The raised portion 10 a is formed by raising a portion located on the base end portion of the soundproof top plate 7 higher than the other portions. The raised portion 10 a rises smoothly from a flat portion, and the top portion is formed as an upwardly convex curved surface. The top portion 10 a is formed so as to fall substantially vertically from the top portion toward the base end portion of the soundproof top plate 7.
The surface of the sound absorbing material 10 is covered with a thin film. The thin film is formed of a material that does not pass dust, moisture, moisture, and the like and transmits sound waves. Examples of such a material include a polyethylene film having a thickness of 30 μm or less.
[0015]
Such a sound absorbing material 10 is fixed as follows. That is, as shown in FIG. 3, the sound absorbing material 10 is installed on the upper surface of the soundproof top plate 7. Between the end portions of the adjacent sound absorbing materials 10, a pressing plate 11 is bridged and placed on the end portions of the sound absorbing material 10. Further, the pressing plate 11 is mounted on the support beam 6 by anchors 12 and 12. It is connected to the flange 6a. Then, by tightening the nut 12a screwed to the anchor 12, the sound absorbing material 10 is sandwiched together with the soundproof top plate 7 between the pressing plate 11 and the upper flange 6a. 7 is fixed to the upper surface. As shown in FIG. 2, the anchor 12 is arranged at a plurality of locations (for example, two locations) in the width direction (left and right direction in FIG. 2) of the sound absorbing material 10, and the sound absorbing material 10 is fixed by the anchor 12.
[0016]
In the soundproof wall for a railway having such a configuration, the rolling noise of the train (noise generated when the wheel travels on the rail) is diffracted at the front end (inner end) of the soundproof top plate 7 and the soundproof top plate. 7 is absorbed by the sound absorbing material 10 and further diffracted and propagated at the base end of the sound absorbing material 10. Since there is a raised portion 10a in the diffracted portion, noise can be reduced by the raised portion 10a, and noise transmitted to the region behind the soundproof side wall 3 can be reduced.
[0017]
In this way, by providing the sound absorbing material 10 having the raised portion 10a on the upper surface of the soundproofing top plate 7, noise can be reduced, and it is not necessary to raise the sound insulating plate vertically as in the prior art. It is not necessary to perform reinforcement or maintenance in consideration, and thus the cost can be reduced.
Further, the raised portion 10 a of the sound absorbing material 10 is located on the base end portion of the soundproof top plate 7, so that the raised portion 10 a is located immediately above the soundproof side wall 3. Therefore, it is possible to prevent the soundproof top plate 7 from being bent downward by the raised portion 10a, and to reduce the load on the soundproof side wall 3 and the support beam 6 that supports the soundproof top plate 7.
Furthermore, since the surface of the sound absorbing material 10 is covered with a thin film, it is possible to prevent dust, moisture, and moisture from adhering to the sound absorbing material 10, and thus the sound absorbing ability of the sound absorbing material 10 can be easily maintained.
[0018]
FIG. 4A is a contour diagram showing the noise reduction effect by the noise barrier for railways of this embodiment by the boundary element method, and FIG. 4B shows the noise reduction effect by the conventional noise barrier for railways by the boundary element method. FIG. In the present embodiment shown in FIG. 4A, a sound absorbing material is attached to the upper surface of the soundproofing plate, and the height of the upper portion of the sound absorbing material (the height from the upper surface of the soundproofing plate) is 300 mm. Further, in the prior art shown in FIG. 4B, no sound absorbing material is attached to the top surface of the soundproof top plate, and the height of raising by the shielding plate is 500 mm.
As shown in FIGS. 4 (a) and 4 (b), in this embodiment, it can be seen that the sound pressure is lower than the conventional one on the ground near the 25m point from the viaduct. That is, in this embodiment, it can be seen that the noise reduction effect is excellent even if the raised portion is lower than the conventional shielding plate. For example, at a position 1.2 m above the ground at a point 25 m away from the vehicle, it can be seen that the noise reduction effect is better in the present embodiment. Indicates that the noise is louder than the thin part (the part where the pattern is rough).
[0019]
(Second Embodiment)
FIG. 5 shows a second embodiment of the railway noise barrier according to the present invention. The railway soundproof wall shown in this figure is different from the railway soundproof wall of the first embodiment in the configuration of the sound absorbing material 10, so this point will be described below and is common to the first embodiment. About the part to perform, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
[0020]
That is, the sound absorbing material 10 is fixed to the upper surface of the soundproof top plate 7 as in the first embodiment, but the front end portion 10b of the sound absorbing material 10 covers the front end portion of the soundproof top plate 7. The soundproof top plate 7 extends to the lower surface.
In this way, the tip 10b of the sound-absorbing material 10 extends to the lower surface of the soundproofing plate 7 so as to cover the tip of the soundproofing plate 7, so that the rolling noise of the train (wheels run on the rails). The noise generated when the sound is diffracted at the front end (inner end) of the soundproof top plate 7 is partially absorbed by the front end 10b. Propagating noise can be further reduced.
[0021]
【The invention's effect】
As described above, according to the first aspect of the present invention, by providing a sound absorbing material having a raised portion on the upper surface of the soundproof top plate, noise can be reduced, and the sound insulation plate is raised vertically as in the prior art. Since it is not necessary, it is not necessary to perform reinforcement or maintenance in consideration of the influence of wind and rain, etc., thus reducing the cost.
In addition, since the raised portion of the sound absorbing material is located on the base end portion of the soundproof top plate, it is possible to prevent the soundproof top plate from being bent downward by the raised portion and to reduce the load burden on the soundproof side wall.
According to the second aspect of the present invention, the front end portion of the sound absorbing material extends to the lower surface of the soundproof top plate so as to cover the front end portion of the soundproof top plate. The noise generated when traveling on the top is diffracted by the tip when the tip (inner end) of the soundproof top plate is diffracted, so that it propagates from the top to the region behind the soundproof side wall. Noise can be further reduced.
[0022]
According to the third aspect of the invention, since the surface of the sound absorbing material is covered with a thin film, it is possible to prevent dust, moisture, and moisture from adhering to the sound absorbing material, and thus the sound absorbing ability of the sound absorbing material can be easily achieved. Can be maintained.
[Brief description of the drawings]
FIG. 1 is a perspective view for explaining a first embodiment of a railway noise barrier according to the present invention.
FIG. 2 is a cross-sectional view of a railway noise barrier.
FIG. 3 is a side sectional view of the main part of the soundproof wall for railways.
FIG. 4 is a diagram for explaining the noise reduction effect by the railway noise barrier according to the present invention, in which (a) is a contour diagram showing the noise reduction effect by the railway noise barrier according to the embodiment by the boundary element method; b) is a contour diagram showing the noise reduction effect of the conventional railway noise barrier by the boundary element method.
FIG. 5 is a cross-sectional view for explaining a second embodiment of the railway noise barrier according to the present invention.
FIG. 6 is a perspective view showing an example of a conventional railway soundproof wall.
FIG. 7 is a cross-sectional view of a railway noise barrier.
[Explanation of symbols]
3 Soundproof side wall 4 Track 7 Soundproof top plate 10 Sound absorbing material 10a

Claims (3)

A soundproof wall for railways comprising a soundproof side wall extending along the track on the side of the track, and a soundproof top plate protruding substantially horizontally from the upper end of the soundproof side wall to the track side,
The upper surface of the sound insulation ceiling plate is sound absorbing material is provided, the sound absorbing material, have a raised portion consisting What upper portion located on the base end portion of the sound insulation ceiling plate Mori higher by other parts And
The raised portion rises smoothly from a flat portion, and the top portion has an upwardly convex curved surface, and is formed so as to be lowered substantially vertically from the top portion toward the base end portion of the soundproof top plate. Sound barrier for railways. The noise barrier for railway according to claim 1,
The soundproof wall for railways, wherein the sound absorbing material has a front end portion extending to a lower surface of the soundproof top plate so as to cover a front end portion of the soundproof top plate. The noise barrier for railway according to claim 1 or 2 ,
A soundproof wall for railways, wherein a surface of the sound absorbing material is covered with a thin film.

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