JP2020159074A - Sound insulation construction method of tunnel soundproof door and sound insulation structure of tunnel soundproof door - Google Patents

Abstract

To provide sound insulation structure for a soundproof door 20 of a tunnel 10 in which sound insulation performance of the soundproof door 20 can be improved relative to a wide low frequency band.SOLUTION: Sound insulation structure for a soundproof door 20 of a tunnel 10 includes a first fixing plate 60 extending upward from a top edge 32 of a vehicular door 30 provided to the soundproof door 20, and first bolts 62 for fixing the first fixing plate 60 to the soundproof door 20. Sound insulation structure for the soundproof door 20 of the tunnel 10 also includes a second fixing plate 70 extending downward from a bottom edge 34 of the vehicular door 30, and second bolts 72 for fixing the second fixing plate 70 to base concrete 40.SELECTED DRAWING: Figure 1

Description

The present invention relates to a sound insulation construction method for a soundproof door of a tunnel and a soundproof structure of the soundproof door of a tunnel.

In general, in excavation and civil engineering work for roads and railway tunnels, noise such as machine vibration generated during excavation and blasting noise generated during blasting work is frequently generated. The noise generated at this time causes a great deal of discomfort to the workers at the site and the residents in the vicinity, and may also have an adverse effect on health. Therefore, sufficient sound insulation measures are required when performing tunnel civil engineering work.

In particular, at construction sites such as mountain tunnels that involve blasting work, it is common to install soundproof doors near the tunnel entrance in order to prevent the tunnel blasting sound from leaking to the external environment. This is to obtain a sound insulation effect by blocking the tunnel entrance with a soundproof door made of steel or concrete, which has a large mass.

However, the tunnel blasting sound is a loud sound having a wide range from a low frequency band to a high frequency band. When trying to deal with such a bursting sound with a conventional soundproof door, a sound insulation effect can be obtained for the sound in the high frequency band according to the mass of the door, but even a member with a large mass can easily pass through the low frequency. The reduction effect is small for the sound in the band.

Therefore, the tunnel entrance or the inside of the tunnel is closed with a partition wall, one end is opened into the tunnel well portion, the other end is closed, and a plurality of pipes having different path lengths are installed on the face side of the predetermined partition wall. A vessel (Patent Document 1) has been proposed. According to the present invention, a muffling effect can be obtained also for a sound in a low frequency band among tunnel blasting sounds.

Japanese Unexamined Patent Publication No. 2011-256609

However, in the method proposed in Patent Document 1, since the sound wave from the bursting sound source and the sound wave reflected by the tube are in opposite phases and cancel each other out to mute the sound, a specific frequency is muted by a plurality of tubes. Although the effect is obtained, the muffling effect cannot be obtained for a wide frequency band. That is, in this method, even if a tube having a sound deadening effect for specific sound waves such as 63 Hz, 32 Hz, and 16 Hz is prepared, it is the same as 16 Hz, 32 Hz, and 63 Hz for sound waves of, for example, 20 Hz and 40 Hz between them. No muffling effect can be obtained.

Therefore, an object of the present invention is to provide a sound insulation construction method for a soundproof door of a tunnel and a soundproof structure for the soundproof door of a tunnel, which can improve the sound insulation performance of the soundproof door in a wide low frequency band.

The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as the following aspects or application examples.

[1] One aspect of the sound insulation construction method for the soundproof door of the tunnel according to the present invention is
It is a sound insulation construction method for the soundproof door of the tunnel.
It is characterized by including at least one of a step of fixing the upper end of the vehicle door provided in the soundproof door to the soundproof door and a step of fixing the lower end of the vehicle door to the base concrete.

According to one aspect of the sound insulation construction method for the soundproof door of the tunnel, the sound insulation performance of the soundproof door of the tunnel can be improved for a wide low frequency band.

[2] In the sound insulation construction method for the soundproof door of the tunnel,
The vehicle door is a double door having a first door and a second door.
The first door and the second door can be fixed at the mating portion.

According to one aspect of the sound insulation construction method for the soundproof door of the tunnel, the sound insulation performance of the soundproof door of the tunnel can be further improved for a wide low frequency band.

[3] One aspect of the sound insulation structure of the soundproof door of the tunnel according to the present invention is
The soundproof structure of the soundproof door of the tunnel
A first fixing plate extending upward from the upper end of the vehicle door provided on the soundproof door, and
The first bolt that fixes the first fixing plate to the soundproof door,
It is characterized by including.

[4] One aspect of the sound insulation structure of the soundproof door of the tunnel according to the present invention is
The soundproof structure of the soundproof door of the tunnel
A second fixing plate extending downward from the lower end of the vehicle door provided on the soundproof door, and
The second bolt that fixes the second fixing plate to the base concrete,
It is characterized by including.

According to one aspect of the sound insulation structure of the soundproof door of the tunnel, the sound insulation performance of the soundproof door of the tunnel can be improved in a wide low frequency band.

[5] In the sound insulation structure of the soundproof door of the tunnel,
The vehicle door is a double door having a first door and a second door.
A third fixing plate extending from the first door to the second door side,
A third bolt that fixes the third fixing plate to the second door,
Can be further included.

According to one aspect of the sound insulation structure of the sound insulation door of the tunnel, the sound insulation performance of the sound insulation door of the tunnel can be further improved in a wide low frequency band.

According to the present invention, it is possible to provide a sound insulation construction method for a soundproof door of a tunnel and a soundproof structure for the soundproof door of the tunnel, which can improve the sound insulation performance of the soundproof door in a wide low frequency band.

It is a front view of the soundproof door of the tunnel which concerns on this embodiment. It is sectional drawing AA of the soundproof door of the tunnel which concerns on this embodiment. It is BB sectional view of the soundproof door of the tunnel which concerns on this embodiment. It is a vertical sectional view explaining the superstructure. It is a vertical sectional view explaining the substructure. It is a cross-sectional view explaining the merging part. It is a graph which shows the relationship between the reduction amount of the sound insulation performance of Example 1 and a center frequency. It is a graph which shows the relationship between the reduction amount of the sound insulation performance of Example 2 and a center frequency.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the embodiments described below do not unreasonably limit the contents of the present invention described in the claims. Moreover, not all of the configurations described below are essential constituent requirements of the present invention.

One aspect of the soundproofing construction method for the soundproof door of the tunnel according to the embodiment of the present invention is the soundproofing construction method for the soundproof door of the tunnel, in which the upper end of the vehicle door provided in the soundproof door is the soundproof door. It is characterized by including at least one of a step of fixing to the base concrete and a step of fixing the lower end of the vehicle door to the base concrete.

One aspect of the soundproof structure of the soundproof door of the tunnel according to the embodiment of the present invention is the soundproof structure of the soundproof door of the tunnel, and the first one extending upward from the upper end of the vehicle door provided in the soundproof door. It is characterized by including a fixing plate and a first bolt for fixing the first fixing plate to the soundproof door.

One aspect of the soundproofing structure of the soundproofing door of the tunnel according to the embodiment of the present invention is the soundproofing structure of the soundproofing door of the tunnel, and the second one extending downward from the lower end of the vehicle door provided in the soundproofing door. It is characterized by including a fixing plate and a second bolt for fixing the second fixing plate to the base concrete.

1. 1. Soundproof Door The soundproof structure of the soundproof door 20 of the tunnel 10 according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a front view of the soundproof door 20 of the tunnel 10 according to the present embodiment, FIG. 2 is a sectional view taken along the line AA of the soundproof door 20 of the tunnel 10 according to the present embodiment, and FIG. It is BB sectional view of the soundproof door 20 of the said tunnel 10.

Examples of the tunnel 10 include a mountain tunnel. In the mountain tunnel, the bedrock of the ground is destroyed by blasting work with dynamite, and the tunnel is dug. The blasting sound associated with the blasting work propagates in the tunnel 10 toward the tunnel entrance 12. A soundproof door 20 is installed so as to block the tunnel entrance 12 in order to prevent blasting sound from leaking to the outside from the tunnel entrance 12 which is the opening of the tunnel 10.

The soundproof door 20 is installed so as to close the tunnel entrance 12 of the tunnel 10. The soundproof door 20 includes a sound insulation plate 16 fixed to a tunnel entrance 12, a wind pipe connecting portion 14 to which a wind pipe is connected, a vehicle door 30 that opens and closes in a double door, and a human door 50 that people pass through. To be equipped with.

The sound insulation plate 16 is constructed without gaps along the inner surface of the tunnel entrance 12, and has, for example, three openings. A wind pipe connecting portion 14, a vehicle door 30, and a human door 50 are provided in each of the three openings of the sound insulating plate 16. The sound insulation plate 16 has, for example, an H-shaped steel frame 26 so as to surround the top and left and right of the vehicle door 30. The frame 26 includes a horizontal frame 26a on the upper side of the vehicle door 30, and vertical frames 26b and 26b on the left and right sides of the vehicle door 30. The sound insulating plate 16 has a structure in which a sound absorbing material is sandwiched between two metal plates. As the metal plate, a metal plate such as a steel plate can be used. As the sound absorbing material, glass wool, soft urethane foam, or the like can be used. The sound insulating plate 16 may be a metal plate sprayed with concrete.

The air duct connection portion 14 is a circular opening provided in the sound insulation plate 16. The air duct is a pipe for supplying air into the tunnel and is connected to the blower. The air pipe is connected to the sound insulation plate 16 at the air pipe connecting portion 14.

The vehicle door 30 is a double door that allows the vehicle to pass through the inside of the tunnel 10. Vehicles include heavy machinery working inside tunnels and vehicles for carrying out rocks generated by blasting. The vehicle door 30 is a double door having a first door 36 and a second door 38. The first door 36 and the second door 38 have hinge portions between the left and right ends and the vertical frames 26b and 26b, and can be rotated and opened / closed with respect to the sound insulating plate 16. The first door 36 and the second door 38 have a summoning portion 39 substantially in the center. Therefore, the vehicle door 30 can be opened to the tunnel entrance 12 side in a double door from substantially the center to the left and right.

The vehicle door 30 can be made of the same material as the sound insulating plate 16. The vehicle door 30 has a structure in which a sound absorbing material is sandwiched between two metal plates made of metal, for example, steel plates. Concrete may be sprayed on the outer surface or the inner surface of the vehicle door 30 to increase the mass of the metal plate, or the sound insulation structure of JP-A-2017-227109 may be further adopted to increase the rigidity of the metal plate.

The vehicle door 30 has a plurality of (for example, four) bars 31 so that the bars 31 do not open the first door 36 and the second door 38 when blasting. The bar 31 is dropped from above into the L-shaped hardware (latch) provided on the first door 36 and the second door 38 to prevent the vehicle door 30 from opening, but between the bar 31 and the hardware. There is a gap in. Therefore, the first door 36 and the second door 38 are allowed to move back and forth by about several mm, and the sound insulation plate 16 and the vehicle door 30 cannot be integrated with the bar 31 alone. That is, since the vehicle door 30 can be moved back and forth with respect to the sound insulation plate 16, the rigidity of the soundproof door 20 as a whole is low just by hanging the bar 31 on the vehicle door 30, and the sound wave in a particularly low frequency band is low. Sound insulation performance is low.

The sound insulation effect depends on a law called the rigidity law in which the sound insulation effect is regulated according to the rigidity of the structure in the frequency range below the resonance frequency of the structure, and is equal to or higher than the resonance frequency of the structure. In the frequency domain, the sound insulation effect depends on the mass law, which is regulated according to the mass of the structure. By adopting the fixed structure described below, the soundproof door 20 increases the rigidity of the soundproof door 20 as a whole so that the resonance frequency of the soundproof door 20 becomes high, and the sound insulation performance in a frequency band lower than the resonance frequency. To improve.

2. 2. Fixed Structure The fixed structure of the vehicle door 30 in the soundproof door 20 will be described with reference to FIGS. 1 to 6. FIG. 4 is a vertical cross-sectional view for explaining the superstructure 22, FIG. 5 is a vertical cross-sectional view for explaining the lower structure 24, and FIG. 6 is a cross-sectional view for explaining the combined portion 39. 4 to 6 show a state in which the vehicle door 30 is closed.

As shown in FIGS. 1 and 4, the superstructure 22 of the soundproof door 20 has a first fixing plate 60 extending upward from the upper end 32 of the vehicle door 30 provided on the soundproof door 20 and the first fixing plate 60 being soundproof. Includes a first bolt 62 (shown in FIG. 4) for fixing to the door 20.

The first fixing plate 60 is made of metal, for example, a steel plate. A plurality, for example, six of the first fixing plates 60 are welded to the upper ends 32 of the first door 36 and the second door 38 at intervals. The first fixing plate 60 is, for example, an L-shaped steel in which a part is cut out. The first fixing plate 60 has a plurality of, for example, two through holes at the top and bottom. Frame 2 of the sound insulation plate 16 corresponding to the through hole when the vehicle door 30 is closed
The first nut 64 as a female thread portion is fixed to the horizontal frame 26a of No. 6 by welding.

With the vehicle door 30 closed, one of the flat surfaces of the L-shaped steel, which is the first fixing plate 60, is brought into contact with the horizontal frame 26a of the sound insulating plate 16 above the upper end 32. The first bolt 62 is inserted into the through hole of the first fixing plate 60, and the first bolt 62 is fastened to the first nut 64. As a result, the upper end 32 of the vehicle door 30 is fixed to the horizontal frame 26a of the sound insulation plate 16, and the vehicle door 30 is restricted from moving back and forth. The horizontal frame 26a is fixed to the vertical frames 26b and 26b. The upper side of the vertical frames 26b and 26b is fixed to the tunnel 10, and the lower side is fixed to the floor concrete or the base concrete 40.

As shown in FIGS. 1 and 5, the lower structure 24 of the soundproof door 20 has a second fixing plate 70 extending downward from the lower end 34 of the vehicle door 30 and a second fixing plate 70 for fixing the second fixing plate 70 to the base concrete 40. Includes 2 volt 72 (shown in FIG. 5). A rubber plate is provided on the lower end 34 so as to close the gap between the lower end 34 and the base concrete 40.

The second fixing plate 70 is made of metal, for example, a steel plate. A plurality of, for example, six second fixing plates 70 are attached to the lower ends 34 of the first door 36 and the second door 38 with the mounting bolts 74 in a state where the vehicle door 30 is closed. The second fixing plate 70 is, for example, an L-shaped metal fitting. The second fixing plate 70 has, for example, long through holes in the vertical direction. This is because the base concrete 40 sinks with the progress of the construction, and the distance between the base concrete 40 and the lower end 34 increases.

A plurality of nut anchors 76 having an opening at the upper end are embedded in the base concrete 40 at intervals. As for the base concrete 40, concrete is cast according to the height of the ground of the tunnel 10. The base concrete 40 may be precast concrete.

With the vehicle door 30 closed, the second fixing plate 70 is attached to the vehicle door 30 with mounting bolts 74 so as to hang down from the lower end 34. The lower surface of the second fixing plate 70 is brought into contact with the base concrete 40, the second bolt 72 is inserted into the through hole provided in the second fixing plate 70, and the second bolt 72 is fastened to the female screw of the nut anchor 76. To do. As a result, the lower end 34 of the vehicle door 30 is fixed to the base concrete 40, and the vehicle door 30 is restricted from moving back and forth. In the present embodiment, the second fixing plate 70 is fixed to the tunnel 10 side of the vehicle door 30, but not limited to this, the second fixing plate 70 is fixed to the tunnel entrance 12 side of the vehicle door 30, that is, to the outside of the tunnel 10. You may. If it is outside the tunnel 10, the installation work of the second fixing plate 70 can be performed without entering the tunnel 10, so that safety is improved and construction labor can be saved.

In this way, the vehicle door 30 is restricted from moving back and forth with respect to the sound insulation plate, so that the vehicle door 30 is integrated with the sound insulation plate 16 and the rigidity of the entire soundproof door 20 is improved. By improving the rigidity of the soundproof door 20, the sound insulation performance of the soundproof door 20 of the tunnel 10 can be improved in a wide low frequency band. In order to improve the rigidity of the soundproof door 20, it is preferable to fix both the upper end 32 and the lower end 34 of the vehicle door 30, but only one of the upper end 32 and the lower end 34 may be fixed. This is because even if only one of the upper end 32 and the lower end 34 is fixed, the rigidity of the soundproof door 20 is improved and the sound insulation performance is improved accordingly.

As shown in FIGS. 1 and 6, the soundproof door 20 includes a third fixing plate 80 extending from the first door 36 toward the second door 38, and a third bolt for fixing the third fixing plate 80 to the second door 38. 82 (shown in FIG. 6) and. As shown in FIG. 6, a third fixing plate 80 extending from the second door 38 to the first door 36 side may be further provided on the face side, or may be provided only on the face side.

The third fixing plate 80 is made of metal, for example, a steel plate. A plurality of, for example, six of the third fixing plates 80 are welded to the combined portion 39 of the first door 36 and the second door 38 with an upper and lower interval. The third fixing plate 80 is welded to the first door 36. For example, when the third fixing plate 80 is also attached to the face side as shown in FIG. 6, it is welded to the second door 38. The third fixing plate 80 is, for example, flat steel. The third fixing plate 80 extends from the welded door to the other door side and has a through hole. When the vehicle door 30 is closed, the third nut 84 as a female screw portion is fixed to the other door by welding at a position corresponding to the through hole.

With the vehicle door 30 closed, the mating portion 39 of the first door 36 is brought into contact with the second door 38. The third bolt 82 is inserted into the through hole of the third fixing plate 80 and the through hole of the first door 36, and the third bolt 82 is fastened to the third nut 84. Similarly, the second door 38 is fastened to the first door 36 with the third bolt 82 and the third nut 84. As a result, the first door 36 and the second door 38 are integrated to further improve the rigidity of the vehicle door 30.

By integrating the first door 36 and the second door 38 to improve the rigidity of the vehicle door 30, the sound insulation performance of the soundproof door 20 of the tunnel 10 can be further improved in a wide low frequency band. ..

3. 3. Construction Method With reference to FIGS. 1 to 6, a sound insulation construction method for the soundproof door 20 of the tunnel 10 according to the present embodiment will be described.

As shown in FIGS. 1 and 4, the vehicle door 30 is closed, and the upper end 32 of the vehicle door 30 provided on the soundproof door 20 is fixed to the soundproof door 20 and integrated. More specifically, the vehicle door 30 is closed, the first fixing plate 60 is brought into contact with the horizontal frame 26a, the first bolt 62 is inserted into the through hole of the first fixing plate 60, and the first bolt 62 is inserted. Fasten to the first nut 64.

As shown in FIGS. 1 and 5, the lower end 34 of the vehicle door 30 is fixed to the base concrete 40. More specifically, the second fixing plate 70 is attached by the mounting bolt 74 so as to hang down from the lower end 34, the second bolt 72 is inserted into the through hole provided in the second fixing plate 70, and the second bolt 72 is inserted. Is fastened to the nut anchor 76.

Either the upper end 32 or the lower end 34 may be fixed first. Further, at least one of a step of fixing the upper end 32 to the soundproof door 20 and a step of fixing the lower end 34 to the base concrete 40 may be executed.

Since the rigidity of the soundproof door 20 is improved by fixing the vehicle door 30 to the sound insulation plate 16, the sound insulation performance of the soundproof door 20 of the tunnel 10 can be improved in a wide low frequency band.

Further, as shown in FIGS. 1 and 6, the first door 36 and the second door 38 of the vehicle door 30 are fixed by the combined portion 39. More specifically, with the vehicle door 30 closed, the third bolt 82 is inserted into the through hole of the third fixing plate 80, and the third bolt 82 is fastened to the third nut 84.

By integrating the first door 36 and the second door 38 to improve the rigidity of the vehicle door 30, the sound insulation performance of the soundproof door 20 of the tunnel 10 for a wide low frequency band can be improved by the vehicle door 30. It can be further improved compared to the state where only the top and bottom are fixed.

As the first embodiment, at an actual tunnel construction site, a height of about 7300 mm × a width of about 12
The upper end of the vehicle door of the 000 mm soundproof door was fixed to the soundproof plate by six first fixing plates. The height of the vehicle door was about 4400 mm and the width was about 5000 mm.

A simulated blasting sound was generated inside the tunnel (face side), and the noise was measured with a microphone installed at a position 5 m outside the tunnel entrance and shown in the graph of FIG. FIG. 7 is a graph in which the noise reduction amount is plotted on the vertical axis in the measurement result of Example 1 with the noise measurement result before fixing the upper end of the vehicle door as 0 dB. The horizontal axis of FIG. 7 is the center frequency of noise. The larger the reduction amount (dB), the better the sound insulation performance of the first embodiment as compared with that before fixing the vehicle door.

According to FIG. 7, the resonance frequency of the soundproof door of Example 1 is around 8 Hz, and the sound insulation performance is improved in the measured wide frequency band of 3.15 Hz to 250 Hz as compared with that before the vehicle door is fixed. Further, although the experimental results are omitted, it was confirmed that the sound insulation performance was improved to that of the first embodiment even when only the lower end of the vehicle door was fixed by the six second fixing plates.

In the second embodiment, in addition to fixing the upper end of the first embodiment, the lower end of the vehicle door was further fixed with six second fixing plates, and the mating portion was fixed with six third fixing plates.

Noise was measured in the same manner as in Example 1, and the measurement results are shown in the graph of FIG. FIG. 8 is a graph in which the noise reduction amount in the measurement result of Example 2 is plotted on the vertical axis, assuming that the noise measurement result before fixing the vehicle door is 0 dB. The horizontal axis of FIG. 8 is the center frequency of noise. The larger the reduction amount (dB), the better the sound insulation performance of the second embodiment as compared with that before fixing the vehicle door.

According to FIG. 8, the resonance frequency of the soundproof door of Example 2 is around 10 Hz, and the sound insulation performance is improved in the measured wide frequency band of 3.15 Hz to 250 Hz as compared with that before the vehicle door is fixed. In particular, since the resonance frequency of Example 2 is higher than the resonance frequency of the soundproof door of Example 1, the sound insulation performance in the frequency band lower than the resonance frequency is improved as compared with Example 1. This is considered to be an improvement in sound insulation performance in the low frequency band due to the rigidity law.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the present invention includes substantially the same configurations as those described in the embodiments (eg, configurations with the same function, method, and result, or configurations with the same purpose and effect). The present invention also includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. Further, the present invention includes a configuration that exhibits the same action and effect as the configuration described in the embodiment or a configuration that can achieve the same object. The present invention also includes a configuration in which a known technique is added to the configuration described in the embodiment.

10 ... Tunnel, 12 ... Tunnel entrance, 14 ... Wind pipe connection, 16 ... Sound insulation plate, 20 ... Soundproof door, 22 ... Upper structure, 24 ... Lower structure, 26 ... Frame, 26a ... Horizontal frame, 26b ... Vertical frame, 30 ... Vehicle door, 31 ... Bar, 32 ... Top, 34 ... Bottom, 36 ... 1st door, 38 ... 2nd door, 39 ... Meeting part, 40 ... Base concrete, 50 ... Person door, 60 ... No. 1 fixing plate, 62 ... 1st bolt, 64 ... 1st nut, 70 ... 2nd fixing plate, 72 ... 2nd bolt, 74 ... mounting bolt, 76 ... nut anchor, 80 ... 3rd fixing plate, 82 ... 3rd Bolt, 84 ... 3rd nut

Claims (5)

It is a sound insulation construction method for the soundproof door of the tunnel.
The tunnel is characterized by including at least one of a step of fixing the upper end of the vehicle door provided on the soundproof door to the soundproof door and a step of fixing the lower end of the vehicle door to the base concrete. Sound insulation construction method for soundproof doors. In claim 1,
The vehicle door is a double door having a first door and a second door.
A sound insulation construction method for a soundproof door of a tunnel, characterized in that the first door and the second door are fixed at a combined portion. The soundproof structure of the soundproof door of the tunnel
A first fixing plate extending upward from the upper end of the vehicle door provided on the soundproof door, and
The first bolt that fixes the first fixing plate to the soundproof door,
The sound insulation structure of the soundproof door of the tunnel, which is characterized by including. The soundproof structure of the soundproof door of the tunnel
A second fixing plate extending downward from the lower end of the vehicle door provided on the soundproof door, and
The second bolt that fixes the second fixing plate to the base concrete,
The sound insulation structure of the soundproof door of the tunnel, which is characterized by including. In claim 3 or 4,
The vehicle door is a double door having a first door and a second door.
A third fixing plate extending from the first door to the second door side,
A third bolt that fixes the third fixing plate to the second door,
The sound insulation structure of the soundproof door of the tunnel, which further includes.

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