JP3054752B2 - Reduction method of pressure wave caused by equipment pit in tunnel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a low frequency pressure wave of 5 to 15 Hz generated when a train passes at a high speed of about 270 km / h or more through an equipment pit provided in a tunnel. Vibration is given by resonating with the fittings (natural frequency) of the house, so to prevent this,
The present invention relates to a method for reducing generation of a pressure wave in an equipment pit.

[0002]

2. Description of the Related Art Generally, when a train or the like enters a tunnel at a high speed, a compression wave is generated in the tunnel. This compression wave
There is a problem that the light propagates through the tunnel at the speed of sound and is radiated to the outside from the tunnel exit side, and when radiated, generates a popping sound (pneumatic sound) called a dawn and vibrates windows and doors of a nearby building. The problem of the pneumatic noise has been well known in the past, and the larger the pressure gradient of the wavefront of the compression wave arriving at the tunnel exit side, the larger the sound becomes. Is also known to have the property of being proportional to the cube of the speed V at which the train enters the tunnel.

For this reason, conventionally, at the tunnel entrance side,
The size of the opening area is larger than the cross-sectional area of the tunnel, and the length is 10 to 50 depending on the magnitude of reduction of the tunnel micro-pressure wave.
A cover (usually referred to as a tunnel buffer) having the same shape as a tunnel of about m is installed, and the cross-sectional area and length of the opening of the cover and the center of the side of the cover are inserted. A window with an optimal area determined by the train shape has been opened. Then, part of the compression wave generated when the train enters the tunnel is released from the window, and the pressure gradient of the wave front of the compression wave is made gentle, so that the compression wave propagates through the tunnel at the speed of sound. In this way, air pressure noise generated when radiated at the tunnel exit side is reduced.

[0004]

However, in spite of taking measures to reduce the pneumatic noise provided with a cover, when a Shinkansen train travels in a tunnel at a high speed of about 270 km or more, it is accompanied by this. There was a problem that the fittings of the house at the exit of the tunnel vibrate.

[0005]

SUMMARY OF THE INVENTION The present invention is to provide a method capable of clarifying the cause of pneumatic noise different from the compression wave generated when a train enters a tunnel and reducing the noise. Is what you do.

According to the first aspect of the present invention, there is provided a device pit for installing equipment to be used for running a train in a tunnel at right angles to a traveling direction. By installing a blocking member for closing the entrance in the equipment pit, the low-frequency pressure wave generated when the train passes through the equipment pit at high speed is reduced in the equipment provided on the tunnel wall in the direction of This is a method of reducing pressure waves caused by equipment pits in a tunnel, characterized in that the pressure waves are reduced.

According to a second aspect of the present invention, the low frequency pressure wave is formed through a 7.1 m ² equipment pit and a train at a speed of 265 km / h or more. 2. The method according to claim 1, wherein the frequency component is a frequency component between 5 and 15 Hz generated when passing through the tunnel.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below with reference to the embodiments of the invention shown in the drawings. The present inventors have repeatedly measured and analyzed the cause of the generation of air pressure noise different from the compression wave generated when the train enters the tunnel during the actual operation of the Shinkansen. As a result, it was found that the cause was the equipment pit installed in the tunnel.

[0009] Furthermore, the occurrence does not appear remarkably on the Shinkansen running at 230 km / h or less and the Shinkansen running at about 250 km / h, and in the case of the Shinkansen Nozomi running at about 270 km / h and at around 300 km / h. It is generated only in the case of a high-speed Shinkansen such as WIN350 during experimental driving, the frequency of the air pressure noise is extremely low frequency air pressure of 5 to 15 Hz, and the depth of the equipment pit is 5 m It has been clarified that the low-frequency air pressure noise is generated only when:

As shown in FIG. 4, in the Iwakuni Tunnel with a length of 5132 m between Hiroshima Station and Shin-Iwakuni Station on the Sanyo Shinkansen, the equipment pits 2 and 1 have a depth of 5 m and 2 m.
The equipment pit 2 having a depth of 5 m is provided on the left and right wall sides of the tunnel 3 at intervals of about 500 m, and the equipment pit 1 having a depth of 2 m is provided on the way.
Is provided. As shown in FIGS. 1 to 3, these equipment pits 2 and 1 each have an entrance (opening) width of 3 m.
It has a rectangular shape with a height of 1.8 m and a circular arc shape formed on a rectangular shape, and has a sectional area of 7.1 m ² .

Thus, of these equipment pits 2 and 1,
The problem is the equipment pit 2 having a depth of 5 m. This is clear from the measurement results shown in FIG. This figure shows that the length between Hiroshima Station and Shin-Iwakuni Station on the Sanyo Shinkansen is 5132 m.
3 is a drawing showing the passing situation when the Shinkansen Nozomi travels at 272 km / h in the Iwakuni tunnel of Iwakuni, and the degree of vibration of the glass door inside the house of a private house.

As shown in FIG. 5A, the Shinkansen train travels in the tunnel 3 from Shin-Osaka (East Exit) to Hakata (West Exit), and the leading vehicle moves into the tunnel 3. Approximately 68 seconds after the rush, the car is passing the tunnel west exit. The rear end of the Shinkansen train passes about 6.6 seconds behind the leading car. The vertical axis of FIG. 3A shows the relationship between the distance from the entrance side to the exit side of the tunnel 3 and the position of the equipment pit 2, and the horizontal axis shows time.

That is, FIG. 5 (a) is a distance-time diagram showing the situation of the Shinkansen train passing through the tunnel, and can be seen by comparing this with the pressure wave measurement result shown in FIG. 5 (b). For example, when a Shinkansen train passes through the equipment pit 2, a pressure wave is generated, and when this pressure wave is emitted from the tunnel exit (west exit) at the speed of sound, a large vibration is given to the glass door in the house. You can see that there is. From this,
When the Shinkansen passes through the equipment pit 2 with a depth of 5 m at a high speed of about 270 km / h (minimum value is at least 265 km / h), a low-frequency pressure wave is generated that vibrates the glass door of the house on the exit side of the tunnel. It became clear that we were doing.

The frequency band of the pressure wave that vibrates the glass door of the house on the exit side of the tunnel is completely unknown and cannot be predicted. Therefore, in order to determine the frequency band that affects the vibration of the glass door, the present inventors collect a large number of measurement data using band filters of various frequency bands, and clarify by analyzing this data. And As a result of analyzing the data collected in this way, it was found that the pressure wave for vibrating the glass door of the house was a low-frequency band and also coincided with the natural frequency band of the fitting. In the case shown in FIG. 5B, the measurement is performed using a bandpass filter that passes 10 to 13 Hz.

Therefore, it is apparent that the pressure wave generated due to the passage of the Shinkansen train through the equipment pit 2 is giving vibration to the glass door in the house near the tunnel exit side. The present inventors have studied the countermeasures. The present inventors have paid attention to taking the countermeasures, assuming that the cross-sectional areas installed in the same tunnel 3 are both 7.1 m.
^In the equipment pit 2 and the equipment pit 1, a low-frequency pressure wave that vibrates the glass door of the house on the tunnel exit side is generated only in the equipment pit 2. The fact is that pressure waves of low frequency enough to vibrate are not generated. In equipment pit 2 and equipment pit 1,
As described above, only the depth dimension is different, and the equipment pit 2 is 5 m in depth, while the equipment pit 1 is 2 m in depth.

From this, it is predicted that if the depth of the equipment pit 2 is at most 2 m, a pressure wave of a low frequency enough to vibrate the glass door of the house will not be generated, as shown in FIGS. As shown in each figure (a) and (b), the existing equipment pit 2 is provided with a closing member 4 for closing the same, and the equipment pit 2 having a depth of 5 m is reduced to a depth of 2 m or less. It was remodeled, and it was confirmed how much the closing member 4 had a sufficient effect of reducing the low-frequency pressure wave, which was a problem.

The results are shown in FIGS. 6A and 6B.
As shown in FIG. In this test, as shown in FIGS. 4 and 6 (a), the third equipment pit 2 from the east exit of the Iwakuni tunnel 3 was provided with a closing member 4 of Type 1 having the shape shown in FIG.
Is installed in the fourth equipment pit 2 from the east exit, and a Type 2 closing member 4 having the shape shown in FIG. 2 is installed in the fourth equipment pit 2 from the east entrance, and a Type 3 closing member 4 having the shape shown in FIG. I went. The closing member 4 of Type 1 shown in FIG.
Is the one in which the equipment pit 2 is completely closed, and Typ shown in FIG.
The closing member 4 of e2 is provided with a door 5 that can be opened and closed, and the closing member 4 of Type 3 shown in FIG. 3 has an opening 6 on the lower side.

As shown in FIG. 6 (b), the test was conducted before the closing members 4 were installed, on the first day after the countermeasures were taken, and on the two days after the countermeasures were taken. Data were measured three times for convenience. Moreover, Type 1 of the first day of measures
In this case, the test was performed without applying a caulking material between the closing member 4 and the equipment pit 2, and in Type 1 on the second day of the measures, the caulking material was applied and the sealing was performed completely. Ty on the first day of measures
In pe2, a caulking material was provided between the closing member 4 and the equipment pit 2, and the door 5 was completely closed. However, in Type2 on the second day of the measure, the caulking material was left as it was,
The door 5 was opened by 27%. Further, in Type 3 on the first day of the measure, the caulking material was applied between the closing member 4 and the equipment pit 2, but in Type 3 on the second day of the measure, the caulk material was applied.

Furthermore, the running speed of the Shinkansen train at the time of the measurement before the countermeasure in FIG. 4B is 270 km / h.
The running speed at the time of the measurement on the first day after the countermeasure is 272.
km / h, and the running speed at the time of measurement on the second day after the countermeasure was 267 km / h. The pressure wave was measured using a bandpass filter (BPF) that passes only low frequencies of 10 to 15 Hz at a point 65 m away from the cover (buffer) on the tunnel exit (west exit) side. This is based on the fact that the natural frequency of the glass door of the house to be measured was around 11 Hz,
A frequency band that is considered to have the largest correlation is set.

The test results performed under these measurement conditions are as shown in FIGS. 6A and 6B.
In the measurement before the countermeasures, the number of Shinkansen trains in tunnel 3 was 270
Along with a pressure wave (called a tunnel micro-pressure wave) generated when the vehicle enters at a high speed of km / h, each time a Shinkansen train passes through each equipment pit 2 in the tunnel 3 at the speed described above,
A large compression wave having a low frequency of 10 to 15 Hz appears remarkably, and this pressure wave resonates with a fitting such as a glass door in a house and gives a rattling to the fitting.

In the measurement waveform on the first day after the countermeasure, in the first and second equipment pits 2 from which the countermeasures according to the present invention are not taken from the entrance side of the tunnel, the Shinkansen train enters the tunnel 3 at 272 km / km. In addition to the pressure wave generated when the vehicle enters at a high speed of h, a pressure wave that causes vibration of a fitting in the house is generated. On the other hand, in the third and fourth equipment pits 2 from the tunnel entrance side where the measures of Type 1 and Type 2 according to the present invention shown in FIGS. 1 and 2 were taken, low-frequency pressure waves were not measured. It is apparent that the closing member 4 suppresses the generation of the low frequency of 10 to 15 Hz in this case. However, in the fifth equipment pit 2 from the tunnel entrance side where the measures of Type 3 shown in FIG. 3 according to the present invention were taken, a low-frequency pressure wave that caused vibration of the fittings in the house was generated. It has been found that if the opening ratio of the closing member 4 is large, the reduction effect is lost.

Next, in the measurement waveform on the second day after the countermeasure, in the first and second non-measurement equipment pits 2 from the tunnel entrance side, the pressure wave which also causes vibration of the fittings in the house is generated. Although generated, the pressure wave of the low frequency was not measured in the equipment pit 2 in which the measures of Type 1 shown in FIG. Further, when the door 5 of the closing member 4 is opened in the equipment pit 2 in which the countermeasure for Type 2 shown in FIG. 2 that is the fourth from the tunnel entrance side is opened, a slight low-frequency pressure wave is measured. Further, in the fifth equipment pit 2 from the tunnel entrance side where the measure of Type 3 shown in FIG. 3 was taken, a low-frequency pressure wave was measured as in the case of the first day after the measure.

As described above, Type 1 or Ty
When the closing member 4 of pe2 was installed, the low-frequency pressure wave which caused the vibration of the fittings in the house was not measured, and it was found that there was a sufficient reduction effect. Also, when the door 5 was provided, it became clear that there was no problem if the door 5 was closed. However, when the opening ratio of the closing member 4 is increased as in Type 3, the effect of reducing the pressure wave is almost eliminated. Furthermore, even if the sealing member 4 and the equipment pit 2 were sealed with the caulking material, no obvious difference appeared. In short, it is desirable that the closing member 4 installed in the equipment pit 2 be fully closed as much as possible, though a small gap is allowed.

The present invention is not limited to the above-described embodiment. In particular, it is difficult to specify the value of the frequency because the natural frequency of the fitting itself in the house varies. Strictly speaking, it should be a frequency due to fitting resonance.
According to the measurement results of this time, in the case of a glass door of a private house, the natural frequency is 11 Hz, and in the case of a similar general house fitting, it can be predicted that the range is 5 to 15 Hz. It is considered to be. In addition, as for the equipment pit 1 having a depth of 2 m, since a pressure wave of a low frequency enough to vibrate the glass door of the house at the tunnel exit side is not generated, the depth dimension of the closing member 4 installed in the equipment pit 2 is: It is sufficient if the distance is within 2 m from the entrance of the equipment pit 2.

Further, the speed at which the low frequency which is a problem when the Shinkansen passes through the equipment pit 2 in the tunnel is 26 as measured at the second day after the countermeasure shown in FIG.
7 km / h, and a low frequency of 10 to 15 Hz is generated at this time.
m / h will be included, and it is easy to predict that at or above about 265 km / h, low frequencies of interest will be generated.

Furthermore, the main component of the low-frequency pressure wave generated when the Shinkansen train (Nozomi) running at about 270 km / h passes through the equipment pit 2 is 10 to 15 Hz.
WI during test running at 300 km / h
In the case of N350, the main component is 5 to 10 Hz, and it is known that there is some frequency variation depending on the head shape and passing speed of the train.

[0027]

As described above, in the present invention,
The equipment pit provided in the tunnel is provided with a closing member for closing the entrance, so it is possible to reduce low-frequency pressure waves generated when the train passes through the equipment pit at high speed. It is possible, and it is possible to prevent vibration such as rattling that has occurred in a fitting of a house near the tunnel exit side due to a low-frequency pressure wave.

Therefore, even when a train running at a high speed of 265 km / h or more, such as a Shinkansen train, passes through the tunnel, the fittings of the private house near the tunnel exit side do not vibrate. It is possible to increase the speed of the train.

[Brief description of the drawings]

FIG. 1 shows a closing member of Type 1 according to the present invention. FIG. 1 (a) is a front view of an equipment pit, and FIG. 1 (b) is a longitudinal sectional side view.

FIGS. 2A and 2B show a closing member of Type 2 according to the present invention. FIG. 2A is a front view of an equipment pit, and FIG.

3A and 3B show a closing member of Type 3 according to the present invention, wherein FIG. 3A is a front view of an equipment pit, and FIG. 3B is a vertical sectional side view.

FIG. 4 is a schematic plan view showing the positions of equipment pits in the Iwakuni tunnel of the Sanyo Shinkansen.

FIG. 5 (a) is a distance-time diagram showing a situation in which a Shinkansen train passes through a tunnel, and FIG. 5 (b) is a diagram showing a pressure wave generated when the Shinkansen train passes through an equipment pit in the tunnel; It is a figure which shows the correlation with the vibration of the fittings of the house of an exit side.

6A and 6B show measurement test data according to the present invention. FIG. 6A is a distance-time diagram showing a situation of a Shinkansen train passing through a tunnel, and FIG. 6B is a diagram measured at the tunnel exit side at that time. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Equipment pit 2m in depth 2 ... Equipment pit 5m in depth 3 ... Tunnel 4 ... Closure member 5 ... Door

Continuing from the front page (72) Kazuo Uchida 2-4-24 Shibata, Kita-ku, Osaka-shi West Japan Railway Company (72) Inventor Tsuyoshi Ide 2-4-2-4 Shibata, Kita-ku, Osaka West Japan Railway Company In-company (58) Field surveyed (Int.Cl. ⁷ , DB name) E21F 1/00

Claims (2)

(57) [Claims] An equipment pit for installing equipment used for running a train in a tunnel is provided on a tunnel wall surface in a direction perpendicular to a traveling direction. A method of reducing pressure waves caused by equipment tunnels in tunnels, characterized by reducing the low-frequency pressure waves generated when a train passes through equipment tunnels at high speed by installing a closing member of . 2. The low-frequency pressure wave has a sectional area of 7.1 m.
^2. The equipment pit in the tunnel according to claim 1, wherein the frequency component is a frequency component between 5 and 15 Hz generated when the train passes through the ^second equipment pit at a speed of 265 km / h or more. How to reduce pressure waves.