Soundproof building

Abstract

To provide a soundproof building that can suppress noise from leaking outside a soundproof wall.SOLUTION: A soundproof building 1 is constructed to surround a noise source 2. The soundproof building 1 comprises a soundproof wall 20 constructed to surround the noise source 2 and a roof 14 constructed on the upper end of the soundproof wall 20 to cover the noise source 2 from above. The soundproof wall 20 comprises a wall main body 21 and a wall extension part 22, which is a concrete body integrally formed with the wall main body 21 on the lower side surface of the wall main body 21. Surface density of the part P, which is a part where the wall main body 21 and the wall extension part 22 are integrally formed, is more than twice of surface density of the part Q, which is a part where only the wall main body 21 is formed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a soundproof building constructed around a noise source. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there have been soundproof walls constructed by combining a plurality of soundproof panels or soundproof panels in order to insulate noise from a noise source (see Patent Document 1). Patent Document 1 shows a soundproof wall formed by connecting a plurality of soundproof panels. The soundproof panel includes a frame, a reinforcing material provided within the frame, an iron plate layer provided below the reinforcing material, a reinforced concrete layer (concrete layer) cast on the underside of the iron plate layer, and a sound absorbing layer provided on the underside of the reinforced concrete layer with an air layer between them.

[0003] Patent Document 2 shows a sound insulation wall that blocks noise from a noise source by combining multiple sound insulation panels vertically in multiple stages. In this sound insulation wall, different types of sound insulation panels with different sound insulation performance are combined vertically. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-32400 A [Patent Document 2] JP 2016-143049 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a soundproof building capable of suppressing noise from leaking outside the soundproof wall. [Means for solving the problem]

[0006] A soundproof building of a first invention (for example, soundproof building 1 described later) is a soundproof building constructed to surround a noise source (for example, noise source 2 described later), and comprises a soundproof wall (for example, soundproof wall 20 described later) that surrounds the noise source, and a roof (for example, roof 14 described later) that is provided at the upper end of the soundproof wall and covers the noise source from above, and the soundproof wall comprises a wall main body (for example, wall main body 21 described later) and a wall extension portion (for example, wall extension portion 22 described later) made of a concrete body or a steel plate that is provided integrally with the wall main body on a lower side surface of the wall main body, and the surface density of the portion of the soundproof wall where the wall main body and the wall extension portion are integrated is at least twice the surface density of the portion of only the wall main body.

[0007] Here, the surface density refers to the weight per unit area of ​​the soundproof wall when viewed from the side. According to this invention, a wall extension made of concrete or steel plate is provided on the lower side of the wall body, and the surface density of the part where the wall body and the wall extension are integrated is more than twice the surface density of the part of the wall body alone. In this way, by increasing the surface density of a part of the soundproof wall, the natural frequency of the soundproof wall is made to deviate from a specific frequency band, suppressing the propagation of noise. Therefore, it is possible to construct a soundproof building with excellent sound insulation performance by suppressing the leakage of noise generated at the noise source to the outside of the soundproof wall. Furthermore, since the wall extension is provided on only a portion of the side surface of the wall main body, a soundproof building can be constructed in a shorter construction period and at lower cost than if the wall extension was provided on the entire side surface of the wall main body.

[0008] A soundproof building according to a second aspect of the present invention is characterized in that the height of the wall extension portion is 1 / 10 or more and 4 / 10 or less of the height of the wall main body.

[0009] According to this invention, the height of the wall extension is set to 1 / 10 to 4 / 10 of the height of the main wall. For example, if the main wall is 10m high, the height of the wall extension is set to 1m to 4m. Therefore, by providing the wall extension only on the lower part of the soundproof wall, it is possible to suppress the noise generated by the noise source from leaking outside the soundproof wall while suppressing the construction cost of the soundproof wall.

[0010] The soundproof building of the third invention is characterized in that the wall body is constructed by connecting a plurality of panel units (e.g., soundproof panel 23 described below), and the panel unit comprises a rectangular frame body (e.g., frame body 24 described below) made of steel, and a concrete body (e.g., concrete body 25 described below) provided inside the frame body.

[0011] According to this invention, the wall body is constructed by connecting multiple panel units at the construction site (dry construction method), which reduces variation in the quality of the wall body compared to constructing the wall body by pouring concrete at the construction site (wet construction method), and enables a soundproof building to be constructed in a short construction period.

[0012] The soundproof building of the fourth invention is characterized in that it covers muddy water treatment equipment used in muddy water shield construction. Effect of the Invention

[0013] According to the present invention, a soundproof building capable of suppressing noise from leaking outside a soundproof wall can be provided. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a side view of a soundproof building according to one embodiment of the present invention. [Diagram 2] This is a cross-sectional view of the soundproof building taken along line AA. [Diagram 3] BB and CC cross-sectional views of the soundproof building. [Figure 4] 1A and 1B are a front view and a longitudinal sectional view of an analytical model of a soundproof wall on one side of a soundproof building. [Diagram 5] FIG. 13 is a diagram showing medium constants of an analytical model of a soundproof wall. [Figure 6] FIG. 1 is a diagram showing the distribution of impedance levels (17.25 Hz) of a conventional soundproof wall with uniform surface density. [Figure 7] This figure shows the distribution of impedance levels (17.25 Hz) of a soundproof wall with surface density doubled in the bottom 2 m. [Figure 8]This figure shows the impedance level of a soundproof wall that is 10 m wide and 10 m high. [Figure 9] This figure shows the impedance levels of a soundproof wall that is 20 m wide and 10 m high. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The present invention is a soundproof building 1 that is installed in a slurry shield construction and covers a slurry treatment facility (noise source 2). The lower side of a soundproof wall 20 that constitutes the soundproof building has a soundproof wall structure in which a wall main body 21 made of soundproof panels is integrated with a wall extension section 22 made of reinforced concrete or steel. Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a side view of a soundproof building 1 according to an embodiment of the present invention. Fig. 2 is a cross-sectional view of the soundproof building 1 taken along line AA. The soundproof building 1 is a building constructed to surround a noise source 2. The soundproof building 1 includes ground 10 on which the noise source 2, such as a machine, is placed, foundations 11 provided around the ground 10, steel-framed columns 12 provided at predetermined intervals on the foundations 11, horizontal members 13 connecting the columns 12 to each other, soundproof walls 20 supported by the columns 12 and the horizontal members 13 and provided to surround the noise source 2 on all four sides, and a roof 14 provided on the upper end of the soundproof wall 20 to cover the noise source 2 from above. Noise source 2 is, for example, a muddy water treatment facility that is installed above ground when forming an underground tunnel using a muddy water shield method.

[0016] Fig. 3(a) is a BB cross-sectional view of the soundproof building 1 in Fig. 1. Fig. 3(b) is a CC cross-sectional view of the soundproof building 1 in Fig. 1. The soundproof wall 20 comprises a wall main body 21 and a wall extension portion 22 provided integrally with the wall main body 21 on the lower side surface of the wall main body 21. The wall body 21 is formed by connecting a plurality of soundproof panels 23 as panel units. Each soundproof panel 23 is a steel-based soundproof panel filled with concrete, and includes a rectangular frame 24 made of channel steel, a reinforced concrete body 25 provided in the portion surrounded by the frame 24, and stiffening members 26 provided in a lattice pattern in the portion surrounded by the frame 24. The soundproof panel 23 is, for example, a V2 panel manufactured by Daimaru Soundproofing Co., Ltd. The V2 panel is a rectangular panel with a short side length of 1000 mm, a long side length of 4000 mm, and a thickness of 300 mm.

[0017] The wall extension 22 is made of reinforced concrete and is supported between the columns 12. The wall extension 22 and the concrete body 25 of the soundproof panel 23 are connected by a bolt 27 and a nut 28. That is, the bolt 27 penetrates the wall extension 22 and the concrete body 25 of the soundproof panel 23, and the nut 28 is screwed onto the bolt 27 and tightened. In this embodiment, the wall extension 22 is made of reinforced concrete, but this is not limiting, and the wall extension 22 may be made of soundproof panels 23 or steel plates.

[0018] Returning to FIG. 2, the height h of the wall extension portion 22 from the ground 10 is 1 / 10 or more and 4 / 10 or less of the height of the wall main body 21 from the ground 10. The surface density of the portion P where the wall main body 21 and the wall extension portion 22 are integrated is more than twice the surface density of the portion Q where only the wall main body 21 is included. Here, the surface density is the weight per unit area of ​​the soundproof wall in a side view. Specifically, if the wall thickness of the wall main body 21 is t1 and the wall thickness of the wall extension portion 22 is t2, then t2≧t1. Specifically, when the above-mentioned V2 panel is used as the soundproof panel 23, the volume density of the V2 panel is 1130 kg / m 3 The V2 panel is 300mm thick, so the areal density of this V2 panel is 339kg / m 2 It becomes. Therefore, when V2 panels are used for both the wall main body 21 and the wall extension portion 22, in order to make the surface density of portion P where the wall main body 21 and the wall extension portion 22 are integrated twice the surface density of portion Q of only the wall main body 21, the wall thickness of the V2 panel used in the wall extension portion needs to be 300 mm. On the other hand, V2 panels are used for the wall body 21, and steel plates (volume density 7800 kg / m 3 ) is adopted, the thickness of the steel plate constituting the wall extension portion 22 will be thinner than that of a steel-based soundproof panel, at approximately 44 mm.

[0019] [Analysis of soundproof walls] An acoustic vibration coupled analysis was performed using the FDTD method, which uses a unified governing equation that is unified regardless of whether it is solid or air (Toyoda Masahiro, "Development of a general-purpose coupled analysis method using the time-domain finite difference method", Journal of the Acoustical Society of Japan, Vol. 72, No. 11 (2016) pp. 697-702). Considering the size of the vibrating screen in the muddy water treatment facility, which is the noise source, the height of the soundproof wall needs to be about 10m. Therefore, we investigated the cases where the height of the soundproof wall is 10m, and the width of the soundproof wall is 10m and 20m. Fig. 4(a) is a front view of an analytical model of a soundproof wall (10m x 10m x 150mm) on one side of a soundproof building, and Fig. 4(b) is a vertical cross-sectional view of the analytical model of the soundproof wall in Fig. 4(a). The analytical model of the wall was a uniform material with a thickness of 150 mm, and the surface density of this analytical model was matched to the soundproof panel measured. In addition, the medium constants of the analytical model of the soundproof wall, such as Young's modulus and loss, were set as shown in Figure 5 so that they matched the impedance level of the soundproof building measured in the 16 Hz band. The spatial discretization width in the thickness direction of the soundproof building walls was 50 mm, and the spatial discretization width other than the walls was 500 mm. The time discretization width was 0.61 s for the wall parts and 24.4 s for the non-wall parts, with one calculation for the other parts for every 40 calculations for the wall parts.

[0020] Fig. 6 shows the distribution of impedance levels (17.25 Hz) of a conventional soundproof wall with uniform surface density, and Fig. 7 shows the distribution of impedance levels (17.25 Hz) of a soundproof wall with double the surface density in the bottom 2 m. Figures 6 and 7 show that by doubling the surface density in the bottom 2 m of the soundproof wall, the impedance level of the entire soundproof wall increases.

[0021] Fig. 8 is a diagram showing the impedance level versus frequency for a soundproof wall that is 10 m wide by 10 m high. Fig. 9 is a diagram showing the impedance level versus frequency for a soundproof wall that is 20 m wide by 10 m high. 8 and 9, "actual measurement" refers to an actual measurement value, and "prediction" refers to a value obtained by simulation using Finite Difference Time Domain (FDTD). Also, "conventional" refers to a type with uniform surface density.

[0022] The vibrating screen, which is the noise source, generates infrasound in the 16 Hz band. As shown in the "Actual_Conventional" and "Predicted_Conventional" graphs in Figures 8 and 9, the natural frequency (impedance level) of a conventional soundproof wall with uniform surface density drops significantly in the 16 Hz band, making it easy for noise in this band to leak outside. Therefore, the impedance level when the surface density of the bottom 1m, 2m, and 4m of the soundproof wall is doubled was obtained by wave acoustic numerical analysis. As shown in Figures 8 and 9, the impedance level of the soundproof wall changes when the surface density is changed, and the impedance level drop part moves out of the 16Hz band, and as a result, noise in the 16Hz band is less likely to leak to the outside. In particular, when the surface density of the bottom 2m is doubled, the drop in the impedance level in the 16Hz band is the smallest compared to when the surface density of the bottom 1m and 4m is doubled, and it was found to be effective in preventing noise.

[0023] As mentioned above, in the case of a 10m wide x 10m high soundproof wall and a 20m wide x 10m high soundproof wall, even if the surface density of the bottom 4m of the soundproof wall is doubled, the impedance level tends to be high in the 16Hz band, making it difficult to reduce noise. Therefore, the height of the wall extension that constitutes a soundproof building (i.e., the height of the part where the surface density is doubled) must be designed based on the following factors (I) and (II). (I) The height of the wall extension must be adjusted to match the width and height of the soundproof building that surrounds the noise source. Since the soundproof building is designed to adequately cover the noise source and provide the required sound insulation performance, it is important that the height of the wall extension matches the height of the soundproof building. (II) The height of the wall extension must be determined based on the results of analysis such as wave acoustic numerical analysis when a noise source is placed. It is important to design the height of the wall extension taking into consideration how sound waves propagate and reflect inside the building. In particular, to maximize the effect of reducing infrasound in the 16Hz band, it is important to determine the height of the wall extension based on the results of wave acoustic numerical analysis.

[0024] According to this embodiment, the following effects are obtained. (1) A wall extension 22 made of concrete is provided on the lower side of the wall main body 21, and the surface density of a portion P where the wall main body 21 and the wall extension 22 are integrated is set to be at least twice the surface density of a portion Q where only the wall main body 21 is formed. In this way, by increasing the surface density of a portion of the soundproof wall 20, the natural frequency of the soundproof wall 20 is set outside a specific frequency band, thereby suppressing the propagation of noise. Therefore, it is possible to construct a soundproof building 1 with excellent sound insulation performance by suppressing the noise generated by the noise source 2 from leaking outside the soundproof wall. Furthermore, since the wall extension portion 22 is provided on only a portion of the side surface of the wall main body 21, the soundproof building 1 can be constructed in a shorter construction period and at a lower cost than if the wall extension portion 22 were provided on the entire side surface of the wall main body 21.

[0025] (2) Soundproof building 1 is a soundproofing structure that mainly targets infrasound (20 Hz or less) generated from noise source 2. This soundproof building 1 is specialized in soundproofing against infrasound, and can improve sound insulation performance mainly against low-frequency sound of 20 Hz or less. (3) The soundproof building 1 targets the noise source 2 installed on the ground 10. Therefore, the height of the wall extension 22 provided at the bottom of the soundproof wall 20 is set to be 1 / 10 or more and 4 / 10 or less of the height of the wall main body 21. For example, if the height of the wall main body 21 is 10 m, the height of the wall extension 22 is 1 m or more and 4 m or less. Therefore, by providing the wall extension 22 only at the bottom of the soundproof wall 20, the construction cost of the soundproof wall 20 can be reduced while preventing the noise generated by the noise source 2 from leaking outside the soundproof wall 20. (4) Since the wall body 21 is constructed by connecting multiple soundproofing panels 23 at the construction site (dry construction method), the variation in quality of the wall body 21 can be reduced compared to when the wall body is constructed by pouring concrete at the construction site (wet construction method), and the soundproof building 1 can be constructed in a short construction period.

[0026] The present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of the present invention that can achieve the object of the present invention are included in the present invention. [Explanation of symbols]

[0027] 1... Soundproof building 2... Noise source 10... Ground 11... Foundation 12...Column 13...Horizontal member 14...Roof 20: Soundproof wall; 21: Wall body; 22: Wall extension; 23... Soundproof panel (panel unit) 24... Frame 25... Concrete body 26... stiffener 27... bolt 28... nut

Claims

1. A soundproof building constructed around a noise source, A soundproof wall provided to surround the noise source; a roof provided at an upper end of the soundproof wall to cover the noise source from above, The soundproof wall includes a wall body and a wall extension portion made of a concrete body or a steel plate and integrally provided on a lower side surface of the wall body, A soundproof building characterized in that the surface density of the portion of the soundproof wall where the wall main body and the wall extension portion are integrated is at least twice the surface density of the portion of the wall main body alone.

2. 2. The soundproof building according to claim 1, wherein the height of the wall extension is between 1 / 10 and 4 / 10 of the height of the wall body.

3. 3. A soundproof building as claimed in claim 1 or 2, which covers a muddy water treatment facility used in muddy water shield construction.

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