JP6563979B2 - Soundproof door - Google Patents

Description

  The present invention relates to a soundproof door for reducing noise during tunnel excavation.

  In mountain tunnel construction, a blasting method using explosives is used to excavate hard rock. In the blasting method, the energy generated by the explosion of explosives becomes sound pressure, propagates through the air in the tunnel, and is transmitted as noise to the surrounding area outside the tunnel mine. In order to reduce the noise to the surrounding area, a soundproof door is installed at the tunnel pit to block the tunnel space and make sound insulation.

  In general, the sound insulation performance of a soundproof door is improved according to the rigidity law (material hardness) and the mass law (material weight). When there is no gap in the soundproof door, the sound pressure generated in the tunnel mine is converted into door vibration on the inner surface (face side) of the soundproof door, and again converted into sound pressure on the outer surface (outside of the mine). Is considered to be transmitted to the surrounding area as noise. Conventionally, in order to reduce the vibration of the soundproof door that mediates the propagation of sound, the soundproof performance of the soundproof door is enhanced by using a harder and heavier material (for example, see Patent Document 1).

Japanese Utility Model Publication No. 5-61300

  The soundproof door requires a vehicle passage and a mechanism for opening and closing the vehicle door as a vehicle passage portion so that a large vehicle passes when carrying heavy machinery or carrying out excavated soil (rock). . Even if the door is made of a hard and heavy material, the vehicle passage part has an opening and closing mechanism, so the restraint of the member is weak, and it vibrates due to the blasting sound pressure compared to the general members constituting the soundproof door other than the vehicle passage part. Cheap. Sound generated by blasting contains many low-frequency sounds that affect people, such as discomfort, and swaying windows. Low performance.

  Therefore, it has been desired to provide a soundproof door that can improve the sound insulation performance of the passage portion through which the vehicle passes.

The present invention has been made in view of the above problems, and is a soundproof door including a passage portion that allows a vehicle to pass through the tunnel, together with a general member portion adjacent to the inner surface of the tunnel in order to close the tunnel wellhead. A traffic part installed in the center of the tunnel that is separated from the inner surface of the tunnel ,
Consists of two side walls, each extending in the tunnel axis direction from the two ends of the general member portion at the center of the tunnel, and a ceiling that covers the top and covers the two side walls. A passage,
A plurality of doors for opening and closing the passage, provided apart from each other in the tunnel axis direction;
A soundproof door is provided that has different stiffness so that the primary natural frequencies of the plurality of doors do not match.

  ADVANTAGE OF THE INVENTION According to this invention, the sound insulation performance of the traffic part which a vehicle passes can be improved.

The front view and side view which showed an example of the conventional soundproof door. The figure which showed the structural example of the soundproof door. Sectional drawing cut | disconnected by the cutting line BB of the soundproof door shown in FIG. The figure explaining the position which measures the sound insulation performance of a soundproof door. The figure which showed the relationship between a mine sound pressure and the acoustic radiation of a mine inner side soundproof door. The figure which showed the relationship between the sound pressure outside a mine and the sound radiation of a mine outside soundproof door. The side view which showed an example of the soundproof door provided with the passage part of a vehicle. Sectional drawing which showed the 1st example of the soundproof door. Sectional drawing which showed the 2nd example of the soundproof door. Sectional drawing which showed the 3rd example of the soundproof door. Sectional drawing which showed the 4th example of the soundproof door.

  FIG. 1 is a front view and a sectional view showing an example of a conventional soundproof door. FIG. 1A is a front view, and FIG. 1B is a cross-sectional view cut along a cutting line AA. The soundproof door 10 is installed so as to close the tunnel wellhead, and the general member portion 11 constituting the main body of the soundproof door 10, the circular wind tube connection portion 12 to which the wind tube is connected, and a vehicle that allows the vehicle to pass therethrough. A passage unit 13 and a person passage unit 14 that allows a person such as a worker to pass therethrough are provided.

  The structure of the general member portion 11 is, for example, the structure shown in FIGS. FIG. 2A shows a structure in which a sound absorbing material 21 is interposed between two sound insulating plates 20. As the sound insulating plate 20, a metal plate such as a steel plate or an aluminum plate, a plastic resin plate such as polycarbonate, or the like is used. be able to. As the sound absorbing material 21, glass wool, soft urethane foam, or the like can be used. FIG. 2B shows a structure in which sand 23 is filled between the structure shown in FIG. 2A and a plate 22 provided apart from the structure. The plate may be a metal plate or a plastic resin plate.

  FIG. 2C shows a structure in which an expanded metal 24 is used instead of the plate 22 in FIG. 2B and concrete 25 is filled between the structure shown in FIG. 2A and the expanded metal 24. . 2 (d) has the same configuration as that of FIG. 2 (c), but the distance between the structure and the expanded metal 24 is wider than that of the structure of FIG. 2 (c), and the concrete 25 is thicker. It has become. Therefore, the structure in FIG. 2A, the structure in FIG. 2B, the structure in FIG. 2C, and the structure in FIG. 2D are heavier and harder in this order, and the sound insulation performance is improved.

  Referring to FIG. 1 again, the wind pipe is a pipe for supplying air into the tunnel, and is connected to the blower. The wind tube connection unit 12 includes a wind tube connection fitting for connecting the wind tubes. The wind tube connection fitting is a flange, for example, and can connect the wind tube using a fastening member such as a bolt and a nut.

  The vehicle passage portion 13 enables the passage of vehicles for carrying out rocks, earth and sand, etc. generated by carrying in and blasting heavy machinery, and the vehicle passage door 15 and the vehicle passage door 15 can be opened and closed to the general member portion 11. And an opening / closing mechanism 16 coupled to the. The vehicle door 15 is composed of two doors that open from the center to the left and right by an opening and closing mechanism 16 attached to the left and right ends, and each door is an L-shaped handle. 17 is provided. Moreover, the door stop for suppressing the movement to the direction opposite to this one direction is provided so that two doors on either side may open only in one direction. When blasting, the rod-shaped ridge 18 is passed over the ridges 17 of the left and right doors so that the left and right doors are not opened. In the example shown in FIG. 1, the left and right doors are prevented from being opened by the three flanges 18.

  The vehicle door 15 can also have the same structure as the general member portion 11 as shown in FIGS. As the opening / closing mechanism 16, for example, a hinge can be used.

  The human traffic section 14 includes a human door 19 and an opening / closing mechanism that connects the human door 19 to the general member section 11 so that the worker can enter and exit the tunnel mine in order to perform work. . The structure of the person door 19 is the same as that of the general member portion 11 and the vehicle door 15, and the opening / closing mechanism can be the same hinge as that used for the vehicle door 15. Note that the door 19 for the person may be made of a steel plate having a predetermined thickness because an operator cannot open and close if the door is too heavy. Further, a door stop is provided so that the human door 19 can be opened only in one direction.

  3 is a cross-sectional view of the soundproof door 10 shown in FIG. 1 cut along a cutting line BB. The soundproof door 10 is provided with a vehicle door 15 that is opened and closed to allow the vehicle to pass therethrough. When blasting, the left and right doors of the vehicle door 15 are closed for sound insulation. On the other hand, when the vehicle passes, the left and right doors of the vehicle door 15 are opened.

  By the way, if it is going to obtain the sound insulation performance required with one soundproof door 10 as shown in FIG. 1, since the out-of-plane vibration becomes large at the primary natural frequency of the door, it is avoided that the sound insulation performance is lowered. Absent. Both ends of the soundproof door 10 are fixed to the side wall of the tunnel, and when sound pressure is applied, the central portion of the soundproof door 10 vibrates in the tunnel axis direction like a half-wave wave. The primary natural frequency is a frequency specific to the door when both ends of the door are freely vibrated, and the out-of-plane vibration is a vibration component in the tunnel axis direction. Sound insulation performance is obtained by octave band analysis (frequency analysis) of sound pressure waveforms measured inside and outside the mine with the soundproof door 10 in between, and the difference between each frequency (mine sound pressure-sound pressure outside the mine) is calculated as the soundproof door 10. It is evaluated as a sound reduction effect by.

  If the sound insulation performance required by one soundproof door cannot be obtained, it can be dealt with by installing two or more soundproof doors in the tunnel axis direction and increasing the number of soundproof doors.

  Here, the result of having installed two soundproof doors and measuring the sound insulation performance of the soundproof door is shown in FIG. 5 and FIG. 6, and the measurement position is shown in FIG. As shown in FIG. 4, the measurement positions are the general member portion 11a of the soundproof door outside the tunnel's mine, the vehicle passage portion 15a of the soundproof door outside the mine, the general member portion 11b of the soundproof door inside the mine, and the soundproofing inside the mine. There are four locations on the vehicle passage 15b of the door. For comparison, sound pressure was measured inside and outside the mine.

  FIG. 4A shows a state in which the sound pressure is measured outside the tunnel mine, and FIG. 4B shows a state in which the sound pressure is measured in the tunnel mine. FIG. 4C shows the vibration measurement locations of the general member portion and the vehicle passage portion inside the mine and outside the mine between the two soundproof doors, with × marks in the figure. 4A to 4C show a wind tube 26 and a microphone 27 for measuring sound pressure.

  Fig. 5 shows the sound pressure characteristics propagating from the face by converting the vibration characteristics of the soundproof door into acoustic radiation (sound pressure characteristics) using theoretical formulas. It is the figure which showed the sound pressure characteristic to propagate.

  5 and 6, circles indicate the sound pressure characteristics in the vehicle passage parts 13a and 13b shown in FIG. 4C, and squares indicate the sound pressure characteristics in the general member parts 11a and 11b shown in FIG. 4C. The diamonds indicate the sound pressure characteristics outside and inside the mine shown in FIGS. 4 (a) and 4 (b). Comparing the results of FIG. 5 and FIG. 6, even in the case of a high-performance (expensive) door, since the restraint of the vehicle passage portions 13a and 13b is weak, the 1/3 octave band center frequency is 8 Hz or less. The door vibrates greatly, and the sound insulation performance of the low frequency component is lower than that of the general member portions 11a and 11b. An octave band is a frequency width (bandwidth) in which a ratio of an upper limit frequency and a lower limit frequency is 1 octave centering on a certain frequency, and the center frequency is the center frequency. As a result, it can be seen that the sound insulation performance of the vehicle passage portions 13a and 13b has a great influence on the sound pressure characteristics propagating outside the mine.

  In the present invention, in order to improve the sound insulation performance of the vehicle passage section 13, as shown in FIG. 7, a passage 30 is provided that extends in the tunnel axis direction and through which the vehicle passes. FIG. 7 is a front view and a sectional view showing an example of the soundproof door of the present invention. FIG. 7A is a front view, and FIG. 7B is a cross-sectional view taken along a cutting line CC.

  The passage 30 includes two side wall portions extending in parallel to the tunnel axis direction and a ceiling portion covering the two side wall portions and covering the upper portion, and the side wall portion and the ceiling portion are the general member portion 11 and the vehicle door 15. It can be set as the same structure. Further, as shown in FIG. 7B, the vehicle passage portion 13 is provided with a plurality of passage doors 31 and 32 that are provided apart from each other in the tunnel axis direction and open and close the passage 30. Other configurations can be the same as those of the conventional soundproof door shown in FIG.

  When the plurality of passing doors 31 and 32 have the same rigidity with the same primary natural frequency of the doors, there is a possibility that the doors vibrate in the same direction and with the same air. Here, the rigidity indicates the degree of difficulty of deformation with respect to bending. In this case, even if the plurality of passage doors 31 and 32 are provided, the vibration is not attenuated, so that the sound insulation performance is not different from the case of one passage door.

  Therefore, in the present invention, the plurality of doors 31 and 32 have different rigidity so that the primary natural frequency of each door does not match. If the rigidity is different, the way of vibration changes depending on the door, so that vibration does not occur at least in the same direction and with the same amplitude, and the vibration can be surely attenuated. Hereinafter, an example in which the plurality of passing doors 31 and 32 have different rigidity will be described with reference to FIGS.

  In the example shown in FIG. 8, the plurality of passing doors 31 and 32 have the same material, thickness, and structure, and are provided at both ends of the passage 30, but the door opening directions are different. The passing doors 31 and 32 are closed by passing the eaves 18 through the eaves 17, but as a result of the door stop being provided so that the door does not open in the opposite direction, the doors are easily deformed in the opening direction. Therefore, the rigidity can be changed by changing the direction of opening the door.

  In the example shown in FIG. 9, the thickness of the plurality of doors 31 and 32 is the same, but the materials are different. This is because the rigidity changes if the material changes. The structure is not limited to the material, and the structure may be different. For example, the structure shown in FIG. 2B and the structure shown in FIG. 2C can be adopted. In this example, the structure of part of the door is the same, but the overall structure may be different. Further, the structure may be the same and only the material may be different, or the material may be the same and only the structure may be different, or both may be different. In the example shown in FIG. 9, the door opening direction is changed in addition to the material difference, but the door opening direction may be the same direction.

  In the example shown in FIG. 10, the materials and structures of the plurality of doors 31, 32 are the same, but the thicknesses are different. This is because the rigidity changes as the thickness changes. For example, the structure shown in FIG. 2C and the structure shown in FIG. 2D can be adopted. Since the plurality of passing doors 31 and 32 may have different rigidity, the material and structure may be changed together with the thickness. In the example shown in FIG. 10, the door opening direction is changed in addition to the thickness difference, but the door opening direction may be the same direction.

  In the example shown in FIG. 11, the material, structure, and thickness of the plurality of passing doors 31 and 32 are the same, but the shape of the surface is different. In the example shown in FIG. 11, the surface of the passing door 31 is flat, but the surface of the passing door 32 (inner side) is provided with unevenness 33. By providing unevenness 33 by providing unevenness on the surface, the bending rigidity of the passage door 32 can be increased, and the rigidity can be different from that of the flat passage door 31. In this example, the unevenness 33 is provided on the surface as an example. However, it may have different rigidity by providing only protrusions or only grooves. Moreover, it is good also as what has a different rigidity by sticking a sheet-like object. Also in this case, in addition to changing the shape of the surface of the plurality of passing doors 31 and 32, at least one of the material, the structure, the thickness, and the door opening direction may be changed.

  When the plurality of doors 31 and 32 are installed apart from each other, performance degradation due to resonance of the space between the doors becomes a problem. When the distance between the doors coincides with the half wavelength of the incident sound wave (incident wave), when the sound wave reflected by the passing door 32 returns to the passing door 31 and is folded again, the reflected sound wave (re-reflected wave) and the passing door 31 are returned. A phenomenon of resonance that overlaps so that incident sound waves strengthen each other occurs. When the resonance occurs, a large vibration is caused in the passing door 32, and the sound wave is emitted outside the pit with a larger sound pressure.

  However, the low frequency sound has a long wavelength of several tens of meters, and a long passage 30 is necessary to make the door interval coincident with the half wavelength, which is realistic in consideration of cost, installation work of the passage 30, and the like. is not. In the passage 30 of about several meters, even if resonance occurs, they are only slightly strengthened. As described above, the passage doors 31 and 32 have different rigidity, so that only one passage door is provided. The sound insulation performance can be improved compared to the case of.

  In addition, the door space | interval of the some passing doors 31 and 32 should just be spaced apart more than fixed distance, for example, can be 0.5 m-3 m.

  As described above, the vehicle passage portion 13 of the soundproof door 10 is provided with the passage 30 and the plurality of passage doors 31 and 32, and the rigidity of the plurality of passage doors 31 and 32 is made different. Compared to a soundproof door having only a passage door, it is possible to improve the sound insulation performance of low-frequency sound. In addition, when an existing soundproof door corresponding to the passage 30 is already provided and one passage door is attached, the sound insulation performance can be obtained simply by attaching a new passage door apart from the one passage door. It is possible to provide a soundproof door with improved performance at low cost. Furthermore, the human traffic section 14 also includes a passage similar to the vehicle traffic section 13 and a plurality of traffic doors, so that the sound insulation performance of the human traffic section 14 can be improved.

  So far, the soundproof door of the present invention has been described in detail with reference to the embodiments shown in the drawings. However, the present invention is not limited to the above-described embodiments, and other embodiments, additions, and changes are made. It is possible to make modifications within the range that can be conceived by those skilled in the art, such as deletion, and any aspect is included in the scope of the present invention as long as the effects and advantages of the present invention are exhibited.

DESCRIPTION OF SYMBOLS 10 ... Soundproof door 11, 11a, 11b ... General member part 12 ... Wind pipe connection part 13, 13a, 13b ... Vehicle passage part 14 ... Person's passage part 15, 15a, 15b ... Vehicle passage door 16 ... Opening / closing mechanism 17 ... 閂鎹 18 ... 閂 19 ... Personal door 20 ... Sound insulation plate 21 ... Sound absorbing material 22 ... Plate 23 ... Sand 24 ... Expanded metal 25 ... Concrete 26 ... Wind pipe 27 ... Microphone 30 ... Passage 31, 32 ... Passing door 33 ... Unevenness

Claims (2)

A soundproof door having a passage portion that allows a vehicle to pass through the tunnel,
Used together with the general member adjacent to the inner surface of the tunnel to close the tunnel wellhead, the passage portion installed at the center of the tunnel separated from the inner surface of the tunnel ,
The vehicle includes two side walls extending from the two ends of the general member at the center of the tunnel in parallel to the tunnel axis direction, and a ceiling that covers the top and covers the two side walls. And a passage for the
A plurality of passing doors that are provided apart from each other in the tunnel axis direction and open and close the passage,
A soundproof door having different rigidity so that primary natural frequencies of the plurality of passing doors do not match.   2. The soundproof door according to claim 1, wherein the plurality of passing doors have the different rigidity by being different in at least one of a material, a thickness, a structure, a surface shape, and an opening / closing direction.