JP7637546B2 - How to install a retrofit sound absorbing device - Google Patents

Description

The present invention relates to a method for installing a retrofit sound absorbing device that improves soundproofing performance by retrofitting the tip of a pillar-less soundproof wall that does not have a support and is installed alongside a noise source such as a railway or highway.

In recent years, efforts have been made to increase the speed of Shinkansen trains in order to shorten travel times and improve customer service. However, increasing the speed of Shinkansen trains also increases the noise level when the trains are running, and noise control measures are required to address this. Furthermore, as residential development progresses in areas along Shinkansen lines and new houses are built, further noise control measures are required, making it necessary to improve the performance of soundproofing walls.

On the other hand, the applicant developed a top-diffraction type sound insulation wall described in Patent Document 1, in which a noise diffracting device with a noise attenuation effect by multiple diffraction is attached to the tip of the sound insulation wall (soundproof wall). The noise diffracting device 5 described in Patent Document 1 consists of a back panel 9 attached between the supports 3, a horizontal panel 10 joined to the upper end of the back panel 9 and extending in a substantially horizontal direction toward the noise generation side, and an inclined panel 12 joined to the upper part of the back panel 9 via a joint panel 11 and extending diagonally upward toward the noise generation side, and a noise introduction section 13 is formed between the tip of the horizontal panel 10 and the upper end of the inclined panel 12 (see paragraphs [0021] to [0031] of the specification of Patent Document 1, and Figures 2 and 3 of the drawings, etc.). Therefore, by attaching the noise diffracting device 5 to the tip of the soundproof wall, it is possible to improve the soundproofing performance without changing the height of the soundproof wall.

As mentioned above, when the current noise countermeasures are insufficient and there is a demand for improving the soundproofing performance of soundproofing walls, one option is to add a Y-shaped retrofit sound absorbing device with multiple diffraction attenuation effect equivalent to the noise diffraction device 5 of Patent Document 1 to the tip of the existing soundproofing wall. If this can be achieved by adding such a retrofit sound absorbing device, it is possible to improve soundproofing performance while keeping costs down, compared to replacing the existing soundproofing wall with a new one with higher soundproofing performance.

However, in recent years, the installation of so-called pillar-less soundproofing walls, which do not have pillars to secure the panels, has been increasing in order to shorten construction time and reduce construction costs. For example, Patent Document 2 discloses a pillar-less soundproofing panel 1 that includes a housing 2, multiple reflecting plates 16 arranged at required intervals inside the housing 2, and sound-absorbing material 4 arranged between the reflecting plates, in which the multiple reflecting plates 16 are integrated to form a reflecting plate assembly 3, and the reflecting plate assembly 3 is fixed to the housing 2 (see claim 1 in the claims of Patent Document 2, paragraphs [0042] to [0051] of the specification, and Figures 1 to 4 of the drawings, etc.).

When trying to retrofit a horizontally long sound-absorbing device to the tip of such a pillar-less soundproof wall, the following problems arise:

A pillar-less soundproof wall does not have any supports, and the soundproof panels are directly fixed and supported on the reinforced concrete structure that serves as the foundation, so multiple vertical panels are arranged side by side in the direction of the tracks. For this reason, the horizontal sound-absorbing device to be added later is installed across multiple vertical soundproof panels of the pillar-less soundproof wall. In this case, there is a high possibility that the tips of the vertical soundproof panels will have differences in height due to manufacturing errors or construction errors during installation, making it difficult to attach the horizontal sound-absorbing device to be added later. Of course, it is also possible to divide the horizontal sound-absorbing device to be added later into the layout of the vertical soundproof panels of the pillar-less soundproof wall. However, in that case, it is clear that the number of connection points will increase, resulting in higher installation and manufacturing costs.

In addition, when installing a retrofit horizontal sound-absorbing device on a soundproof wall, there is no support, so if the retrofit sound-absorbing device falls off, there is nowhere to attach the fall prevention wire to prevent it from falling or scattering.

On the other hand, as an example of a retrofit soundproofing facility, Patent Document 3 discloses a soundproofing structure for a temporary fencing for a construction site in which a tip-improved silencer 24 is hung with a hook 44 near the upper end of the temporary fencing for the construction site (see claim 1 of Patent Document 3, paragraphs [0036] to [0050] of the specification, and Figures 1 and 2 of the drawings, etc.).

However, the tip-improved silencer 24 described in Patent Document 3 is simply attached to the temporary enclosure with a hook 44, and although it is a technology that can be attached to and removed from an existing vertical wall, it is not a technology that can be applied to soundproof walls, which are permanent structures along railways and expressways. In particular, the soundproofing structure of the temporary enclosure for construction sites described in Patent Document 3 was not able to withstand the wind load caused by the passing of a Shinkansen train.

JP 2005-213753 A JP 2012-180688 A JP 2015-168960 A

The present invention was devised in consideration of the above-mentioned problems, and its purpose is to provide a mounting method and structure for a retrofit sound-absorbing device that can be retrofitted to a soundproof wall to improve the soundproofing performance at low cost.

The method for installing a retrofit sound-absorbing device according to the first invention is a method for adding a retrofit sound-absorbing device to an existing pillar-less soundproof wall in which soundproof panels are directly fixed to a foundation structure without any pillars being installed, and includes a cross-member installation step of fixing a cross-member having a length equal to or greater than the width of a plurality of soundproof panels across the plurality of soundproof panels, and a retrofit sound-absorbing device installation step of fixing the retrofit sound-absorbing device to the cross-member, wherein in the cross-member installation step, the cross-members are fixed in two tiers, one above the other, across the plurality of soundproof panels with a vertical gap between them, and in the retrofit sound-absorbing device installation step, the upper tier cross-member installed across the plurality of soundproof panels is fixed to the top of the retrofit sound-absorbing device and the lower tier cross-member is fixed to the bottom of the retrofit sound-absorbing device, thereby installing the retrofit sound-absorbing device across the plurality of soundproof panels .

The method for installing a retrofit sound absorbing device according to the second invention is the same as the first invention, but is characterized in that the retrofit sound absorbing device has a rear panel and a front panel whose upper end is spaced apart and inclined from the rear panel.

The method for installing a retrofit sound-absorbing device according to the third invention is characterized in that, in the first or second invention, after the cross member installation step, it includes a retrofit sound-absorbing device connection step of connecting the cross member and the retrofit sound-absorbing device via a linear or chain-shaped fall prevention material to prevent the retrofit sound-absorbing device from falling.

The method for installing a retrofit sound-absorbing device according to the fourth invention is characterized in that, in any one of the first to third inventions, the cross member and the retrofit sound-absorbing device are installed on the noise source side of the soundproof panel.

According to the first to fourth inventions, the soundproofing performance of an existing soundproofing wall can be improved at low cost by retrofitting a retrofit sound absorbing device that improves the soundproofing performance to the soundproofing wall. Also, according to the first to fourth inventions, the horizontal member and the retrofit sound absorbing device are joined to the existing soundproofing panel by mechanical joining means such as bolts and rivets, so that the retrofit sound absorbing device has a high degree of fixation, unlike a temporary structure such as the soundproofing structure of the temporary enclosure for a construction site described in Patent Document 3, and can function as a permanent structure that is permanently installed for many years. Furthermore, according to the first to fourth inventions, the horizontal member having a length equal to or longer than the width of a plurality of soundproofing panels is fixed and attached across a plurality of the soundproofing panels, so that the step in the panel outward direction of the soundproofing wall caused by the construction error when installing the existing soundproofing panel can be corrected, and the horizontally long retrofit sound absorbing device can be easily attached in a short time.
Furthermore, according to the first to fourth inventions, the cross members are provided in two tiers, one above the other, with a gap between them on the top and bottom of the soundproofing panel, so that the retrofit sound-absorbing device can be fixed more firmly, improving durability and allowing it to function as a permanent structure.

In particular, according to the third invention, the cross member and the retrofit sound-absorbing device are connected by the fall prevention material, which solves the problem of there being no support pillar and therefore no place to fasten the fall prevention wire, and makes it possible to take measures to prevent the retrofit sound-absorbing device from falling in the unlikely event of an accident.

In particular, according to the fourth invention, since the retrofit sound-absorbing device is attached to the noise source side of the soundproofing panel, installation and maintenance of the retrofit sound-absorbing device can be carried out from the track side or roadway side using a stepladder, eliminating the need to set up temporary scaffolding outside the bridge or on the private land side, shortening the construction period and reducing installation and maintenance costs.

FIG. 1 is a front view showing a soundproof wall to which a retrofit sound absorbing device according to an embodiment of the present invention is attached, as viewed from the noise source side. FIG. 2 is a perspective view showing an existing pillar-less soundproof wall before a retrofit sound absorbing device according to an embodiment of the present invention is attached. FIG. 3 is an exploded perspective view showing the above-mentioned existing pillar-less soundproof wall. FIG. 4 is a perspective view showing a retrofit sound absorbing device according to an embodiment of the present invention. FIG. 5 is a right side view showing the retrofit sound absorbing device. FIG. 6 is a front view of the retrofit sound absorbing device as viewed from the noise side. FIG. 7 is a plan view showing the above retrofit sound absorbing device. FIG. 8 is a partially enlarged perspective view showing an enlarged view of the vicinity of a fall prevention material of a soundproof wall to which a mounting structure for a sound absorbing device according to an embodiment of the present invention is applied. FIG. 9 is a process explanatory diagram showing a cross member installation process in the mounting method for the retrofit sound absorbing device according to this embodiment. FIG. 10 is a partially enlarged view of FIG. 9 showing the cross member installation step of the same. FIG. 11 is a process explanatory diagram showing a process of installing a retrofit sound absorbing device in the mounting method of the retrofit sound absorbing device according to this embodiment.

The following describes in detail the installation method and installation structure of a retrofit sound absorbing device according to an embodiment of the present invention, with reference to the drawings.

<Sound absorbing device mounting structure>
1 to 8, a mounting structure for a sound absorbing device according to an embodiment of the present invention, in which a sound absorbing device is mounted by a mounting method for a retrofit sound absorbing device according to an embodiment of the present invention, will be described. The present invention is an invention that is suitably applied when a sound absorbing device is mounted on an existing pillar-less soundproof wall, and will be described by taking as an example a case in which a modified Y-shaped retrofit sound absorbing device 3 having a damping effect by multiple diffraction etc. is added to an existing pillar-less soundproof wall 10 installed beside a railway line. Fig. 1 is a front view showing a soundproof wall 1 to which a retrofit sound absorbing device 3 according to an embodiment of the present invention is mounted.

As shown in Figure 1, a soundproof wall 1 to which the mounting structure for a sound absorbing device according to an embodiment of the present invention is applied is a mounting structure for adding a modified Y-shaped retrofit sound absorbing device 3 having a damping effect by multiple diffraction, etc., to an existing pillarless soundproof wall 10 via a cross member 2 made of angle iron. Note that the X direction in the figure indicates the pillarless soundproof wall 10, i.e., the soundproof wall direction along the railway (road), and the Y direction indicates the up-down direction. Also, the Z direction indicates the direction perpendicular to the soundproof wall surface that is perpendicular to the panel surface (railroad, road) of the pillarless soundproof wall 10 (same below).

(Pole-less soundproof wall)
First, an existing soundproof wall in which a retrofit sound absorbing device 3 is attached to improve soundproofing performance will be described with reference to Figures 2 and 3. Figure 2 is a perspective view showing an existing support-less soundproof wall 10 before the retrofit sound absorbing device 3 according to the embodiment of the present invention is attached, and Figure 3 is an exploded perspective view showing the existing support-less soundproof wall 10. As shown in Figures 2 and 3, the existing support-less soundproof wall 10 shown in the figures is a support-less soundproof wall in which a soundproof panel 12 (including its frame) is directly fixed to a wall parapet 11, which is a foundation structure made of reinforced concrete, without any support being erected thereon.

The soundproof panel 12 has a roughly vertically long rectangular (rectangular) box-shaped housing 120 made of a metal such as stainless steel plate, plated steel plate, or aluminum plate, with numerous holes 12a drilled into it, and sound-absorbing material (not shown) is loaded into this housing 120.

The sound-absorbing material is preferably a foamed resin such as polyurethane foam, or a fibrous material such as polyester or glass wool, and any material that absorbs noise by attenuating the noise that passes through the holes in the housing 120 through diffuse reflection or the like can be used as appropriate. Note that the material can also be used in pillar-less soundproof walls made of sound-proofing plates such as steel plates that insulate sound by weight, without loading any sound-absorbing material.

As shown in Figures 1 to 3, the soundproof panel 12 has mounting plates 12b extending downward from the lower ends of the front and rear panels of the housing 120. The mounting plates 12b are bolted to the wall balustrade 11 with anchor bolts embedded in the wall balustrade 11, so that the pillar-less soundproof wall 10 is erected without erecting pillars on the wall balustrade 11.

In addition, as shown in Figures 2 and 3, a pair of left and right step portions 12c, 12d are formed on the side of the housing 120, which are provided with steps that fit with the housings 120 of other adjacent soundproofing panels 12. Therefore, adjacent soundproofing panels 12 can fit together and act as one to resist wind loads, etc., when a train passes.

However, there are many different types of existing pillar-less soundproof walls 10, and the width W1 of the soundproof panels 12 is not uniform but also varies (see Figure 2). The width W1 of the soundproof panels 12 in pillar-less soundproof walls 10 is generally between 300 mm and 600 mm. In existing pillar-less soundproof walls 10, the manufacturing and construction errors of the soundproof panels 12 are adjusted by the installation interval G of the soundproof panels 12 in the X direction. For this reason, the width of the installation interval G also generally varies.

Furthermore, as shown in Figure 3, the illustrated pillar-less soundproof wall 10 is erected on the wall parapet 11 by drilling holes in the wall parapet 11 and fastening the mounting plate 12b of the soundproof panel 12 with anchors or the like that are installed afterwards. For this reason, there was concern that the mounting angle of the soundproof panel 12 of the existing pillar-less soundproof wall 10 would vary due to construction errors in the anchors, etc., and the upper end (tip) of the soundproof panel 12 would be misaligned in the illustrated Z direction.

Therefore, in a soundproof wall 1 to which the mounting structure for a sound-absorbing device according to this embodiment is applied, a cross member 2 made of angle iron is fixed across multiple soundproof panels 12 near the upper ends of the soundproof panels 12 of an existing pillar-less soundproof wall 10, and then a retrofit sound-absorbing device 3 (described below) is attached. This makes it easy to mount the retrofit sound-absorbing device 3 even if there is a step between the upper ends of multiple soundproof panels 12.

In other words, as shown in FIG. 1, the soundproof wall 1 to which the mounting structure for a sound absorbing device according to this embodiment, which adds a retrofit sound absorbing device 3 to an existing pillar-less soundproof wall 10, is applied, comprises two horizontal members 2, 2 made of angle iron, and a retrofit sound absorbing device 3 attached via these horizontal members 2, 2.

2 and 3, the side of the housing 120 is formed with a pair of left and right steps 12c, 12d that are provided with a step to fit with the housing 120 of another adjacent soundproof panel 12, but the side of the housing 120 does not have to have a step. Also, in FIG. 3, the pillar-less soundproof wall 10 is erected on the wall balustrade 11 by drilling holes in the wall balustrade 11 and fastening the mounting plate 12b of the soundproof panel 12 with an anchor or the like that is installed later, but it is also possible to place a base plate on the top surface of the wall balustrade 11 without using the mounting plate 12b and attach the housing 120 to the base plate. In this way, the illustrated embodiments are merely examples of embodiments that are embodied in carrying out the present invention, and the technical scope of the present invention should not be interpreted as being limited by the illustrated embodiments.

(cross member)
As shown in FIG. 1, the cross members 2 are fixed in two tiers, one above the other, across a number of soundproofing panels 12, ..., 12, with a gap between them above and below. An upper cross member 21 is attached along the upper end of the soundproofing panel 12, and a lower cross member 22 is attached to the top of the soundproofing panel 12 with a specified gap between them.

However, the cross member 2 can also be the upper cross member 21 only. The retrofit sound absorbing device 3 attached to the cross member 2 is heavy, and there is little risk of the lower end lifting up due to wind loads caused by trains passing by, etc., as long as the upper end is secured in place.

As shown in FIG. 1, the upper cross member 21 has a length equivalent to about four soundproofing panels 12 with a width W1 (see FIG. 2), and the lower cross member 22 has a length equivalent to about three soundproofing panels 12 with a width W1. Of course, the length of the upper cross member 21 and the lower cross member 22, which are the cross members 2, is not limited to the length shown in the example, and it is sufficient that they are attached across multiple soundproofing panels 12. In other words, the length of the cross member 2 needs to be at least multiple (multiple) of the width W1 according to the length in the X direction of the retrofit sound absorbing device 3 to be attached.

The cross members 2 (upper cross member 21 and lower cross member 22) in this embodiment are made of equal-leg angle steel. Of course, the cross members in this invention are not limited to steel materials such as angle steel, and may be any bar material with the strength to withstand the wind load when a train passes. However, it is preferable that the cross members 2 are made of bar material with a cross-sectional shape having orthogonal faces, such as angle steel or channel steel. This is because it improves the cross-sectional performance of the cross member 2, and it is possible to achieve a weight reduction while maintaining a predetermined strength. In addition, this improves the ease of installation of the retrofit sound-absorbing device 3 described below.

The horizontal members 2 (upper horizontal member 21 and lower horizontal member 22) are provided with a large number of long holes 21a, 22a that are long in the longitudinal direction (see also Figures 6 and 7). Therefore, in the soundproof wall 1 to which the mounting structure for the sound-absorbing device of the present invention is applied, the length can be adjusted to correspond to the error in the installation interval G of the soundproof panels 12 in the X direction, as described below, and the retrofit sound-absorbing device 3 can be easily installed in a short time.

(Retrofit sound absorbing device: sound absorbing device)
Next, a retrofit sound-absorbing device 3 according to an embodiment of the present invention will be described with reference to Figs. 4 to 8. Fig. 4 is a perspective view showing the retrofit sound-absorbing device 3 according to an embodiment of the present invention. Fig. 5 is a right side view showing the retrofit sound-absorbing device 3, and Fig. 6 is a front view of the retrofit sound-absorbing device 3 as viewed from the noise side. Fig. 7 is a plan view showing the retrofit sound-absorbing device 3. Fig. 8 is a partially enlarged perspective view showing the vicinity of the fall prevention material of the soundproof wall 1.

As shown in Figures 4 to 8, the retrofit sound absorbing device 3 is equipped with a rectangular plate-shaped rear panel 30 extending vertically in the up-down direction, and a rectangular plate-shaped front panel 31 extending diagonally upward from the rear panel 30 toward the noise source, with its upper end spaced apart and inclined from the rear panel 30, and is a retrofit sound absorbing device 3 with a modified Y-shape in vertical cross section. This retrofit sound absorbing device 3 is a sound absorbing device that is retrofitted to an existing pillar-less soundproof wall 10, and improves soundproofing performance by providing a damping effect due to multiple diffraction, etc., against noise that goes around and exceeds the upper end of the soundproof wall 1 due to its modified Y-shape cross section, etc.

In addition, between the rear panel 30 and the front panel 31, a pair of triangular side panels 32 that cover the sides, and multiple triangular intermediate panels 33 that improve the bending rigidity of the retrofit sound absorbing device 3 are provided.

In addition, a sound-absorbing panel 34 is attached to the noise source side (front side) of the front panel 31. This sound-absorbing panel 34 is in the shape of a rectangular box, and has many circular holes 34a drilled on the noise source side (front side).

In this embodiment, the rear panel 30, front panel 31, side panel 32, middle panel 33, and sound-absorbing panel 34 are made of highly weather-resistant plated steel sheets. Of course, these panel materials are not limited to highly weather-resistant plated steel sheets, and may be made of metal sheets such as rust-resistant steel sheets, stainless steel sheets, and aluminum sheets.

The inside of the sound-absorbing panel 34 is filled with a sound-absorbing material (not shown). This sound-absorbing material is a fibrous material made of polyester resin. Of course, the sound-absorbing material filled in the sound-absorbing panel 34 may be other fibrous materials such as foamed resin such as polyurethane foam or glass wool, just like the existing pillar-less soundproof wall 10. In short, the sound-absorbing material filled in the sound-absorbing panel 34 may be any material that absorbs noise by attenuating it through diffuse reflection or the like that passes through the circular holes 34a.

As shown in FIG. 8, the upper cross member 21 and the retrofit sound absorbing device 3 are connected by a fall prevention material 4 made of wire. Of course, the fall prevention material according to the present invention is not limited to wire, and may be any member having a certain strength that can withstand the impact load of the fall of the retrofit sound absorbing device 3, such as a flexible wire or a linear or chain-shaped member.

As shown in Figures 4 to 8, the retrofit sound absorbing device 3 comprises a rectangular plate-shaped rear panel 30 extending vertically in the up-down direction, and a rectangular plate-shaped front panel 31 extending diagonally upward from the rear panel 30 toward the noise source, with the upper end spaced apart from the rear panel 30 and inclined, and although the vertical cross section is shown as a modified Y-shape, this is merely a preferred embodiment. As long as the retrofit sound absorbing device 3 can improve soundproofing performance by being retrofitted to the top of an existing pillar-less soundproof wall 10, the technical scope of the present invention should not be interpreted as being limited by the illustrated embodiment.

<How to install a retrofit sound absorbing device>
Next, a method for attaching a retrofit sound absorbing device according to an embodiment of the present invention will be described with reference to Figures 9 to 11, 1, 5, and 8. The following describes an example of a case in which the retrofit sound absorbing device 3 is attached to the existing pillar-less soundproof wall 10 described above to construct a soundproof wall 1 to which the mounting structure for the sound absorbing device according to the embodiment of the present invention is applied.

(Horizontal member installation process)
Fig. 9 is a process explanatory diagram showing a cross member installation step of the mounting method of the retrofit sound absorbing device according to this embodiment, and Fig. 10 is a partial enlarged view of Fig. 9 showing the cross member installation step. As shown in Figs. 9 and 10, in the mounting method of the retrofit sound absorbing device according to this embodiment, first, a cross member installation step is performed in which the above-mentioned cross member 2 is fixed across and mounted on the multiple soundproof panels 12 of the existing pillar-less soundproof wall 10.

Specifically, in this process, the upper cross member 21, which is an equal-leg angle steel with a length equivalent to about four of the width W1 (see FIG. 2) of the aforementioned soundproofing panel 12, is joined and fixed across multiple soundproofing panels 12 (four in the illustrated embodiment) using mechanical joining means such as bolts or rivets.

In addition, in this process, the upper cross member 21 is fixed across multiple soundproofing panels 12 near the upper ends of the soundproofing panels 12 of the existing pillar-less soundproofing wall 10. This makes it easier to attach the retrofit sound absorbing device 3 in a later process even if there is a step between the upper ends of the multiple soundproofing panels 12.

In short, this process solves the problem of steps occurring between the tips of existing pillar-less soundproof walls 10 due to product manufacturing errors and construction errors during installation, as described in the Background Art section, making it difficult to attach the retrofit sound-absorbing device 3, and improves the construction efficiency of the installation work for the retrofit sound-absorbing device 3.

In addition, in this process, the upper cross member 21 is attached to the noise source side (front side) of the soundproof panel 12. It is also possible to attach the upper cross member 21 to the back side of the soundproof panel 12, but this may reduce the sound absorption efficiency of the retrofit sound absorbing device 3, so it is preferable to attach it to the noise source side (front side) of the soundproof panel 12. In addition, the outside of the pillar-less soundproof wall 10 is often private land, and it is often difficult to set up temporary scaffolding.

In this process, the lower cross member 22 may be attached to the noise source side of the soundproof panel 12 below the upper cross member 21 with a distance corresponding to the height of the retrofit sound absorbing device 3. By doing so, the retrofit sound absorbing device 3 can be placed and attached in a process described later on top of the lower cross member 22 attached in this process, improving the workability when attaching the retrofit sound absorbing device 3, which is a heavy object.

(Retrofit sound absorbing device installation process)
11 is a process explanatory diagram showing the process of installing a retrofit sound absorbing device in the method of installing a retrofit sound absorbing device according to this embodiment. As shown in FIG. 11, in the method of installing a retrofit sound absorbing device according to this embodiment, the retrofit sound absorbing device 3 is fixed to the upper cross member 21 attached to the existing pillar-less soundproof wall 10 in the previous process.

Specifically, as shown in FIG. 6, the lower cross member 22 is previously joined to the lower end of the retrofit sound absorbing device 3 by mechanical joining means such as bolts or rivets. Then, the retrofit sound absorbing device 3 with the lower cross member 22 joined is joined to the upper cross member 21 attached to the existing pillar-less soundproof wall 10 in the previous process by mechanical joining means.

At this time, the retrofit sound absorbing device 3 is attached to the surface of the upper cross member 21 made of equal angle steel that is perpendicular to the surface that abuts against the soundproof panel 12, and is suspended and supported by the upper cross member 21 attached to the soundproof panel 12.

The lower cross member 22 attached to the lower end of the retrofit sound-absorbing device 3 has a surface that is orthogonal to the surface that abuts the retrofit sound-absorbing device 3 attached to the soundproof panel 12. Therefore, the lower part of the retrofit sound-absorbing device 3 is placed on and fixed to the lower cross member 22.

The retrofit sound absorbing device 3 can therefore be firmly fixed to the soundproof panel 12 by the upper and lower cross members 21 and 22, improving durability. This allows the retrofit sound absorbing device 3 attached to an existing pillar-less soundproof wall 10 to function as a permanent structure.

As described above, the upper cross member 21 and the lower cross member 22 of the cross member 2 have long holes 21a, 22a formed in them. This allows the length to be adjusted to accommodate the error in the installation interval G of the soundproof panels 12 along the X direction of the existing pillar-less soundproof wall 10, and the retrofit sound absorbing device 3 can be easily installed in a short time.

In addition, in the previous process, only the upper cross member 21 can be attached to the existing pillar-less soundproof wall 10, and in this retrofit sound-absorbing device installation process, after the retrofit sound-absorbing device 3 is fixed to the upper cross member 21, the lower cross member 22 can be attached to the soundproof panel 12 of the existing pillar-less soundproof wall 10. This is because, ultimately, the retrofit sound-absorbing device 3 can be firmly fixed to the existing pillar-less soundproof wall 10.

In addition, as shown in FIG. 11, by attaching the cross member 2 and the retrofit sound absorbing device 3 to the noise source side of the existing pillar-less soundproof wall 10, the installation and maintenance of the retrofit sound absorbing device 3 can be performed from the track side or roadway side using a stepladder, eliminating the need to install temporary scaffolding on the outside of the bridge or on the private land side, shortening the construction period and reducing installation costs.

(Retrofit sound absorbing device connection process)
As shown in Figure 8, the method for installing a retrofit sound-absorbing device according to this embodiment next involves a retrofit sound-absorbing device connecting step in which the upper cross member 21 and the retrofit sound-absorbing device 3 are connected with the fall prevention member 4 described above. This is to prevent the retrofit sound-absorbing device 3 from falling onto the railway or roadway and causing an accident, even if the retrofit sound-absorbing device 3 should fall off the upper cross member 21. By performing this step, the problem described in the Background Art that there is no support pillar and therefore no place to fasten the fall prevention wire can be solved, and measures can be taken to prevent the retrofit sound-absorbing device 3 from falling.

According to the mounting method and mounting structure for a retrofit sound absorbing device according to the embodiment of the present invention described above, the retrofit sound absorbing device 3 that improves soundproofing performance can be retrofitted to an existing pillar-less soundproof wall 10 to improve soundproofing performance at low cost.

In addition, according to the mounting method and mounting structure for the retrofit sound absorbing device of this embodiment, the cross member 2 and the retrofit sound absorbing device 3 are joined to the existing soundproof panel 12 by mechanical joining means such as bolts and rivets, so unlike temporary structures such as the soundproofing structure of the temporary fencing for construction sites described in Patent Document 3, the retrofit sound absorbing device has a high degree of fixation and can function as a permanent structure that is permanently installed for many years.

Furthermore, according to the mounting method and mounting structure for a retrofit sound absorbing device of this embodiment, a cross member 2 having a length equal to or greater than the width W1 of a plurality of soundproof panels 12 is fixed and mounted across a plurality of soundproof panels 12, so that the step in the outward direction of the panel surface of the soundproof wall 1 caused by construction errors during installation of the existing soundproof panels 12 can be corrected and the horizontally long retrofit sound absorbing device 3 can be easily mounted in a short time.

In addition, according to the mounting method and mounting structure for a retrofit sound absorbing device according to the embodiment of the present invention, the retrofit sound absorbing device 3 can be mounted directly to the soundproof panel 12, so that a common retrofit sound absorbing device 3 can be installed without being limited by the width W1, layout, or type of the existing soundproof panel 12, thereby reducing the number of parts and costs.

In addition, according to the mounting method and mounting structure for a retrofit sound absorbing device of this embodiment, the cross members 2 are provided in two tiers, one above the other, with a gap between them on the soundproof panel, so that the retrofit sound absorbing device 3 can be fixed more firmly, its durability is improved, and it can function as a permanent structure.

The above provides a detailed explanation of the mounting method and mounting structure for a retrofit sound absorbing device according to an embodiment of the present invention. However, the above-mentioned and illustrated embodiments are merely examples of embodiments that are embodied in carrying out the present invention, and the technical scope of the present invention should not be interpreted as being limited by the illustrated embodiments.

1: Soundproof wall (sound absorbing device mounting structure)
2: Horizontal material 21: Upper horizontal material (horizontal material)
21a: Long hole 22: Lower cross member (horizontal member)
22a: Long hole 3: Retrofit sound absorbing device (sound absorbing device)
30: Rear panel 31: Front panel 32: Side panel 33: Middle panel 34: Sound absorbing panel 34a: Circular hole 4: Fall prevention material 10: Pillarless soundproof wall (existing soundproof wall)
11: Wall parapet (foundation structure)
12: Soundproof panel 120: Housing 12a: Hole 12b: Mounting plate 12c, 12d: Step G: Installation interval W1: Width of soundproof panel

Claims (4)

A method for attaching a retrofit sound absorbing device to an existing pillar-less soundproof wall in which a soundproof panel is directly fixed to a foundation structure without a pillar being erected, comprising the steps of:
a horizontal member installation step of fixing and attaching a horizontal member having a length equal to or greater than the width of a plurality of the soundproofing panels across the plurality of soundproofing panels; and a retrofit sound-absorbing device installation step of fixing the retrofit sound-absorbing device to the horizontal member ,
In the cross member installation step, the cross members are fixed in two tiers, one above the other, across the multiple soundproof panels with a vertical gap between them,
In the retrofit sound absorbing device installation step, the upper horizontal member installed across the plurality of soundproof panels is fixed to an upper portion of the retrofit sound absorbing device, and the lower horizontal member is fixed to a lower portion of the retrofit sound absorbing device , thereby installing the retrofit sound absorbing device across the plurality of soundproof panels.
A method for installing a retrofit sound absorbing device. 2. The method for attaching a retrofit sound absorbing device according to claim 1, wherein the retrofit sound absorbing device has a back panel and a front panel whose upper end is spaced apart from and inclined relative to the back panel. 3. The method for installing a retrofit sound-absorbing device as described in claim 1 or 2, further comprising a step of connecting the cross member and the retrofit sound-absorbing device via a linear or chain-shaped fall prevention material after the cross member installation step to prevent the retrofit sound-absorbing device from falling. 4. The method for attaching a retrofit sound absorbing device according to claim 1, wherein the cross member and the retrofit sound absorbing device are attached to the noise source side of the soundproof panel.

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