JP2023074971A - Micro-pressure wave reducing structure - Google Patents

Abstract

To provide a micro-pressure wave reducing structure capable of maintaining the performance of reducing micro-pressure waves radiated from a tunnel portal on the opposite side when a vehicle rushes into the tunnel portal, and capable of reducing micro-pressure waves radiated from a buffer construction entrance of a tunnel buffer construction when the vehicle rushes into the tunnel portal on the opposite side.SOLUTION: A micro-pressure wave reducing structure 5 reduces tunnel micro-pressure waves W2 emitted from a buffer construction entrance 4a of a tunnel buffer construction 4 covering a tunnel portal 3a. The micro-pressure wave reducing structure 5 has a radiating part 6 that opens a part of the tunnel buffer construction 4 and radiates a part of this tunnel micro-pressure wave W2 to the outside to reduce the tunnel micro-pressure wave W2 emitted from the buffer construction entrance 4a when the train 1 rushes into a tunnel portal 3b on the opposite side. The radiating portion 6 opens the stepped portions of buffer construction portions 4A and 4B to radiate part of the tunnel micro-pressure wave W2 to the outside.SELECTED DRAWING: Figure 3

Description

The present invention relates to a micro-pressure wave reducing structure for reducing tunnel micro-pressure waves emitted from a tunnel entrance hood covering a tunnel portal.

As shown in FIG. 21, when the train 101 rushes into the tunnel entrance 103a on the entrance side, a compression wave _W1 is generated in the tunnel 103, propagates in the tunnel ₁₀₃ at the speed of sound, and travels through the tunnel on the opposite side. A pressure wave is radiated to the outside at the wellhead 103b. The pressure wave radiated to the outside is called tunnel micro-pressure wave _W2 . Tunnel micro-pressure waves _W2 cause environmental problems such as blasting noises and shaking the doors and windows of houses, so countermeasures are essential. The magnitude of the tunnel micro-pressure wave _W2 is proportional to the steepness (dp/dt) of the wavefront of the compression wave p in the tunnel. Therefore, if the wave front of the compression wave _W1 is moderated (the pressure gradient is reduced), the tunnel micro-pressure wave _W2 can be reduced.

As shown in FIG. 22, the tunnel entrance hood 104 is a hood-like structure that is installed at the tunnel entrance 103a, has a cross-sectional area 1.4 to 1.5 times that of the main tunnel, and has windows (openings) formed on the sides. is proposed. This tunnel entrance hood 104 moderates the steepness (dp/dt) of the wave front of the tunnel compression wave p generated in the tunnel 103 when the train 101 rushes into the tunnel portal 103a on the entrance side. The tunnel micro-pressure wave _W2 radiated to the outside from the side tunnel portal 103b is reduced.

A conventional tunnel entrance entrance hood opening structure (hereinafter referred to as prior art 1) has an opening with a small opening area on the entrance hood wall on the train entry side of the tunnel entrance hood, and on the opposite side of the entrance hood wall. It has an opening with a large opening area (see Patent Document 1, for example). In this prior art 1, it is not necessary to set the size of the opening for each train having a different head shape or a different tunnel entry speed, thereby reducing the effect of micro-pressure waves. In a conventional tunnel entrance hood (hereinafter referred to as prior art 2), one side of the rectangular opening of the entrance hood faces the open end surface of the entrance hood (see, for example, Patent Document 2). In this prior art 2, pressure fluctuation is made difficult to occur by eliminating one vertical side of the opening.

In prior arts 1 and 2, as shown in FIG. 23, the longer the tunnel entrance hood 104, the better the performance. increases. As a means of solving this problem, tunnel entrance hoods that are short and have the same effect of reducing micro-pressure waves have been proposed. The conventional tunnel entrance entrance hood (hereinafter referred to as prior art 3) does not have side openings in the hood-like structure, and the cross-sectional area of the hood-like structure is 2.2 to 2.6 times the cross-sectional area of the main tunnel. (See, for example, Patent Document 3). In this prior art 3, the cross-sectional area of the hood-like structure is optimally set to reduce tunnel micro-pressure waves without providing side openings.

As shown in FIG. 24, if the cross-sectional area of the extended portion of the tunnel entrance hood 104 on the side of the entrance hood 104a (front end side) is increased, and the tunnel entrance hood 104 is made into two stages of entrance hood portions 104A and 104B, It can be shorter in length than the tunnel entrance hood 104 shown in 23 . As a result, the construction cost can be reduced while maintaining the micro pressure wave reduction performance. In a conventional tunnel entrance hood micro-pressure wave reducing structure (hereinafter referred to as prior art 4), first and second tunnel entrance hoods have a cross-sectional area that increases stepwise from the entrance side tunnel portal toward the entrance hood. It has two entrance hood sections, and the lengths and cross-sectional area ratios of the first and second hood sections are set to predetermined values (see Patent Document 4, for example). In this prior art 4, the performance of the tunnel entrance hood is improved while reducing the construction cost by using the existing tunnel entrance hood.

Patent No. 3475267

Patent No. 4243746

JP 2017-031734 A

Japanese Patent Application Laid-Open No. 2020-100943

As shown in FIG. 25, in prior art 4, tunnel entrance hoods 104A of tunnel entrance hood 104 have a larger cross-sectional area (larger than the tunnel entrance hoods of prior art 1 to 3 (1.4 times that of the main tunnel)). 2.5 to 4.0 times). For this reason, in prior art 4, when the tunnel entrance hood 104 is installed at the tunnel entrance 103a on the entrance side in a double-track tunnel, when the train 101 traveling in the opposite direction enters from the tunnel entrance 103b on the exit side, the cross-sectional area is large. A tunnel micro-pressure wave _W2 is radiated from the entrance hood 104a of the hood 104A. Since the magnitude of the tunnel micro-pressure wave W ₂ is also proportional to the cross-sectional area of the emission port, the tunnel micro-pressure wave W ₂ radiated from the entrance hood 104a having a large cross-sectional area on the tunnel entrance side is It becomes larger than the tunnel micro-pressure wave _W2 radiated from the tunnel entrance hood (1.4 times that of the main tunnel tunnel) of No. 3. For this reason, it is necessary to strengthen countermeasures against the tunnel portal 103b on the opposite side, which causes a problem of increased costs.

An object of the present invention is to provide a tunnel entrance hood when a moving body rushes into the tunnel portal on the opposite side while maintaining the performance of reducing micro-pressure waves emitted from the tunnel portal on the opposite side when a moving body rushes into the tunnel portal. To provide a micro-pressure wave reducing structure capable of reducing micro-pressure waves emitted from a hood entrance.

The present invention solves the above-described problems by means of solutions as described below.
In addition, although the code|symbol corresponding to embodiment of this invention is attached|subjected and demonstrated, it does not limit to this embodiment.
The invention of claim 1, as shown in FIGS. 3, 4 and 25, reduces tunnel micro-pressure waves radiated from the entrance (4a) of the tunnel entrance hood (4) covering the tunnel entrance (3a). A micro-pressure wave reducing structure for reducing tunnel micro-pressure waves (W ₂ ) radiated from the entrance of the tunnel entrance when a moving body rushes into the entrance of the tunnel on the opposite side (3b). is provided with a radiating part (6) for releasing part of the tunnel micro-pressure wave (W ₂₂ ) to the outside.

The invention of claim 2 is the micro-pressure wave reducing structure of claim 1, wherein the cross-sectional area of the tunnel entrance hood increases stepwise from the tunnel entrance toward the entrance of the tunnel entrance. As described above, the tunnel entrance is provided with entrance hoods (4A, 4B), and the radiating portion is a micro-pressure wave reducing structure characterized by opening a stepped portion of the hoods.

According to a third aspect of the invention, in the micro-pressure wave reducing structure according to the first or second aspect, as shown in FIG. A first (4A) and a second hood (4B) are provided in order from this hood entrance toward this tunnel portal so that the cross-sectional area of the hood increases stepwise, and the speed 260 of the moving body is Up to 360 km/h, the length of the front part of the moving body is 15 m or less, the cross-sectional area of the tunnel is A, the cross-sectional area of the first entrance hood is A _h ', the cross-sectional area ratio of the first hood is σ _h '. = A _h '/A, the cross-sectional area of the second entrance hood A _h , and the cross-sectional area ratio of the second hood σ _h = A _h /A, then the first hood hood The cross-sectional area ratio σ _h ' ≈ 2.5 to 3.2, the total length (L _h1 ) of the first entrance hood is 20 m or more, the cross-sectional area ratio σ _h ≈ 1.4 to 1.5 of the second entrance hood, the second The micro-pressure wave reducing structure is characterized in that the total length (L _h2 ) of the entrance hood is 20 m or more, and the length (L _h3 ) of the radiating portion is 20 to 40 m.

According to the invention of claim 4, in the micro-pressure wave reducing structure of claim 1 or claim 2, as shown in FIGS. A first (4A) and a second entrance hood (4B) are provided in order from the entrance of the tunnel entrance toward the entrance of the tunnel so that the cross-sectional area of the entrance hood increases step by step, and the moving body Mach number M, the cross-sectional area A of the tunnel, and the wave front width L _{W0 ≈√A} / M, the cross-sectional area A _h ' of the first entrance hood, the cross-sectional area ratio σ _h ' of the first hood hood = A _h '/A, the total length L _h1 of the first hood hood, the Cross-sectional area A _h of the second entrance hood, cross-sectional area ratio σ _h =A _h /A of the second hood, total length L _h2 of the second hood, length L of the radial portion _h3 , the cross-sectional area ratio σ _h ' of the first entrance hood is ≈2.5 to 3.2, the total length of the first entrance hood is L _h1 >L _W0 ·M/(1−M), the first 2, the cross-sectional area ratio σ _h ≈1.4 to 1.5 of the hood hood, the total length of the second hood hood L _h2 ≧L _h1 , and the length of the radiating portion L _h3 ≈0.6L _W0 . It is a micro-pressure wave reduction structure.

According to the invention of claim 5, in the micro-pressure wave reducing structure according to claim 1 or claim 2, as shown in FIG. A first (4A) and a second hood (4B) are provided in order from this hood entrance toward this tunnel portal so that the cross-sectional area of the hood increases stepwise, and the speed 260 of the moving body is Up to 360 km/h, the length of the front part of the moving body is 15 m or less, the cross-sectional area of the tunnel is A, the cross-sectional area of the first entrance hood is A _h ', the cross-sectional area ratio of the first hood is σ _h '. = A _h '/A, the cross-sectional area of the second entrance hood A _h , and the cross-sectional area ratio of the second hood σ _h = A _h /A, then the first hood hood The cross-sectional area ratio σ _h ' ≈ 2.5 to 3.2, the total length (L _h1 ) of the first entrance hood is 20 m or more, the cross-sectional area ratio σ _h ≈ 1.4 to 1.5 of the second entrance hood, the second The micro-pressure wave reducing structure is characterized in that the total length (L _h2 ) of the entrance hood is 20 m or more, and the length (L _h3 ) of the radiating portion is 15 to 25 m.

According to a sixth aspect of the invention, in the micro-pressure wave reducing structure according to the first or second aspect, as shown in FIGS. A first (4A) and a second entrance hood (4B) are provided in order from the entrance of the tunnel entrance toward the entrance of the tunnel so that the cross-sectional area of the entrance hood increases step by step, and the moving body Mach number M, the cross-sectional area A of the tunnel, and the wave front width L _{W0 ≈√A} / M, the cross-sectional area A _h ' of the first entrance hood, the cross-sectional area ratio σ _h ' of the first hood hood = A _h '/A, the total length L _h1 of the first hood hood, the Cross-sectional area A _h of the second entrance hood, cross-sectional area ratio σ _h =A _h /A of the second hood, total length L _h2 of the second hood, length L of the radial portion _h3 , the cross-sectional area ratio σ _h ' of the first entrance hood is ≈2.5 to 3.2, the total length of the first entrance hood is L _h1 >L _W0 ·M/(1−M), the first 2, the cross-sectional area ratio σ _h ≈1.4 to 1.5 of the entrance hood, the total length of the second hood L _h2 ≧L _h1 , and the length of the radiating portion L _h3 ≈0.35 to 0.4L _W0 . It is a micro-pressure wave reduction structure.

The invention of claim 7 is directed to the micro-pressure wave reducing structure according to any one of claims 1 to 6, as shown in FIGS. ), wherein the opening/closing part closes the radial part when the moving body rushes into the entrance hood, and opens the radial part when the moving body rushes into the tunnel portal on the opposite side. It is a micro-pressure wave reduction structure characterized by

The invention according to claim 8 is the micro-pressure wave reducing structure according to any one of claims 1 to 6, as shown in FIGS. A length variable part (12) is provided, and the length variable part changes the length of the radiating part to a predetermined length (L _h3 ) when the moving body enters the entrance hood, and The micro-pressure wave reducing structure is characterized in that the length of the radiating portion is changed to zero when the moving body rushes into the tunnel portal.

According to the present invention, when a moving body rushes into the tunnel portal, the performance of reducing micro-pressure waves radiated from the opposite tunnel portal is maintained, and when a mobile body rushes into the tunnel portal on the opposite side, the tunnel entrance hood is damaged. It is also possible to reduce the micro-pressure waves emitted from the entrance of the hood.

1 is a schematic diagram showing a state in which a train has rushed into a tunnel entrance hood in the micro-pressure wave reducing structure for a tunnel entrance hood according to the first embodiment of the present invention; FIG. FIG. 2 is a longitudinal sectional view schematically showing a state in which a train has rushed into a tunnel entrance hood in the micro-pressure wave reducing structure for a tunnel entrance hood according to the first embodiment of the present invention; FIG. 4 is a schematic diagram showing a state in which a train has rushed into the tunnel entrance on the opposite side of the micro-pressure wave reducing structure for the tunnel entrance hood according to the first embodiment of the present invention; FIG. 4 is a vertical cross-sectional view schematically showing a state in which a train has rushed into the tunnel entrance on the opposite side of the micro-pressure wave reducing structure for a tunnel entrance hood according to the first embodiment of the present invention; FIG. 3 is a cross-sectional view taken along line V-V of FIG. 2, where (A) is a cross-sectional view when the tunnel entrance hood has a semicircular cross-section, and (B) is a cross-section of the tunnel entrance hood which is rectangular. It is a cross-sectional view of the case. 1 is a schematic diagram of a micro-pressure wave reducing structure for a tunnel entrance hood according to a first embodiment of the present invention; FIG. FIG. 4 is a diagram for defining variables when determining the length of the radiation portion of the micro-pressure wave reducing structure of the tunnel entrance hood according to the first embodiment of the present invention; FIG. and (B) is the definition of the head length of the moving body. FIG. 4 is a schematic diagram for explaining the action of the micro-pressure wave reducing structure of the tunnel entrance hood according to the first embodiment of the present invention; (B) is a schematic diagram for explaining the action when a train rushes in from the tunnel portal. FIG. 6 is a schematic diagram of a micro-pressure wave reducing structure for a tunnel entrance hood according to a sixth embodiment of the present invention, and FIG. (B) is a schematic diagram when the radiating section is oriented perpendicularly to the tunnel entrance hood. FIG. 11 is a configuration diagram of a micro-pressure wave reducing structure for a tunnel entrance hood according to a seventh embodiment of the present invention; FIG. 10 is a schematic diagram of a micro-pressure wave reducing structure of a tunnel entrance hood according to a seventh embodiment of the present invention, where (A) is a schematic diagram showing a state when a train rushes into a tunnel portal, and (B) is the opposite. FIG. 10 is a schematic diagram showing a state when a train rushes into the side tunnel portal; FIG. 11 is a configuration diagram of a micro-pressure wave reducing structure for a tunnel entrance hood according to an eighth embodiment of the present invention; FIG. 10 is a schematic diagram of a micro-pressure wave reducing structure for a tunnel entrance hood according to an eighth embodiment of the present invention, where (A) is a schematic diagram showing a state when a train rushes into a tunnel portal, and (B) is the opposite. FIG. 10 is a schematic diagram showing a state when a train rushes into the side tunnel portal; FIG. 2 is a schematic diagram of a model test apparatus used for experiments on the micro-pressure wave reduction effect of the micro-pressure wave reduction structure of the tunnel entrance hood according to the embodiment of the present invention; FIG. 2 is a schematic diagram of a tunnel entrance hood model used in a test to confirm the performance at the time of entry by the micro-pressure wave reduction structure of the tunnel entrance hood according to the embodiment of the present invention; It is a schematic diagram of a model. (B) is a schematic diagram of a tunnel entrance hood simulating a conventional two-stage entrance hood. FIG. 2 is a schematic diagram of a confirmation experiment of the performance at the time of entry by the micro-pressure wave reducing structure of the tunnel entrance hood according to the embodiment of the present invention, and (A) is a schematic diagram of the confirmation experiment of the proposed entrance hood according to the embodiment. , (B) is a schematic diagram of a confirmation experiment in the case of a conventional two-stage entrance hood. FIG. 5 is a graph showing experimental results of the performance at the time of entry by the micro-pressure wave reducing structure of the tunnel entrance hood according to the embodiment of the present invention; FIG. FIG. 2 is a schematic diagram of a tunnel entrance hood model used in a confirmation experiment of radiation performance by a micro-pressure wave reducing structure of a tunnel entrance hood according to an embodiment of the present invention; It is a schematic diagram of the experiment, (B) is a schematic diagram of a confirmation experiment in the case of a conventional two-stage entrance hood, (C) is a schematic diagram of a confirmation experiment in the case of a conventional normal entrance hood, (D ) is a schematic diagram of a confirmation experiment without a tunnel entrance hood. FIG. 3 is a schematic diagram of a confirmation experiment of radiation performance by a micro-pressure wave reducing structure of a tunnel entrance hood according to an embodiment of the present invention, and FIG. , (B) is a schematic diagram of a confirmation experiment in the case of a conventional two-stage entrance hood. FIG. 4 is a graph showing the experimental results of radiation performance of the micro-pressure wave reducing structure of the tunnel entrance hood according to the embodiment of the present invention, and (A) is a graph showing the experimental results when the speed of the vehicle model is 320 km/h. and (B) is a graph showing experimental results when the speed of the vehicle model is 360 km/h. It is a schematic diagram for explaining the phenomenon of tunnel micro-pressure waves. FIG. 3 is a schematic diagram for explaining the function of a conventional tunnel entrance hood; It is a schematic diagram when the conventional tunnel entrance hood is lengthened. It is a schematic diagram at the time of making the conventional tunnel entrance hood into two steps. It is a schematic diagram when a train rushes in from the opposite side tunnel entrance when the conventional tunnel entrance hood is made into two steps.

(First embodiment)
A first embodiment of the present invention will be described in detail below with reference to the drawings.
A train 1 shown in FIGS. 1 to 5 is a moving object that moves along a track 2. As shown in FIG. A train 1 is, for example, a railway vehicle that runs on a bullet train (registered trademark) at a high speed of 320 km/h or higher. A track 2 is a track (moving route) on which the train 1 travels. The track 2 is, for example, a double track composed of two main lines as shown in FIG. On the up line 2A, the train 1 runs from the end point toward the starting point (traveling direction D ₁ shown in FIG. 5). On the outbound line 2B, the train 1 runs from the starting point toward the terminal point (traveling direction D ₂ shown in FIG. 5). For example, in the case of the Tohoku Shinkansen, the inbound line 2A is the track on which the train 1 heading from the direction of Sendai to the direction of Tokyo runs, and in the case of the Tohoku Shinkansen, the outbound line 2B is the track on which the train 1 heading from the direction of Tokyo to the direction of Sendai runs. It is a line to

The tunnel 3 shown in FIGS. 1 to 5 is a fixed structure (civil engineering structure) for allowing the train 1 to pass through the ground such as a hillside. The tunnel 3 is, for example, a double-track railway tunnel (double-track tunnel) that accommodates the track 2 in one fixed structure, as shown in FIG. As shown in FIGS. 1 and 3, the tunnel 3 includes tunnel portals 3a and 3b, which serve as entrances and exits through which the train 1 enters and exits. 1 and 2, the train 1 running on the outbound line 2B enters the tunnel entrance hood 4 and exits from the tunnel entrance 3b on the opposite side. 2A, the train 1 running on the up line 2A rushes into the tunnel portal 3b on the opposite side, and the train 1 exits the tunnel entrance hood 4 as an example.

The tunnel entrance hood 4 shown in FIGS. 1 to 5 is a fixed structure (civil engineering structure) covering the tunnel portal 3a for reducing the tunnel micro-pressure wave W ₂ . The tunnel entrance hood 4 shown in FIGS. 1 to 5 is, for example, a double-track entrance entrance hood (double-track tunnel entrance hood) that accommodates the track 2 in one tunnel lining. As shown in FIG. 1, the tunnel entrance hood 4 absorbs the pressure gradient ( _Fig . 7A), the tunnel micro-pressure wave _W2 radiated to the outside from the tunnel portal (opposite portal) 3b on the exit side of the tunnel 3 is reduced. Here, the compression wave W1 shown in FIG. ₁ is a pressure wave generated in the tunnel 3 when the head of the train 1 rushes into the tunnel portal 3a. The compression wave _W1 has a positive pressure gradient as shown in FIG. 7(A). The tunnel micro-pressure wave _W2 is a pulse-like pressure wave that is radiated out of the tunnel 3 from the tunnel portal 3b on the opposite side after the compression wave _W1 propagates through the tunnel 3 at the speed of sound. The magnitude of the tunnel micro-pressure wave _W2 is approximately proportional to the pressure gradient of the compression wave _W1 reaching the tunnel portal 3b on the opposite side. The pressure gradient is the time change rate of the wavefront of the compression wave W ₁ propagating in the tunnel 3 . The tunnel entrance hood 4 is, for example, a hood-shaped (cover-shaped) structure made of concrete, reinforced concrete, or steel plate, and as shown in FIGS. It is constructed to extend 3. The tunnel entrance hood 4 has a cross-sectional shape when cut along a plane perpendicular to the center line of the tunnel entrance hood 4, such as a semicircular shape as shown in FIG. is a simple rectangle. The tunnel entrance hood 4 is constructed to have a length corresponding to the speed U of the train 1 and the like. The tunnel entrance hood 4, as shown in FIGS. A side wall 4c forming a side portion, a plurality of entrance hoods 4A and 4B in the length direction of the tunnel entrance hood 4 as shown in FIGS.

The entrance hood sections 4A and 4B shown in FIGS. 1 to 4 are portions that cover the tunnel entrance such that the cross-sectional area of the tunnel entrance hood 4 increases stepwise from the tunnel entrance 3a toward the entrance hood 4a. . Entrance hood section 4A is a first-stage tunnel entrance hood that covers the entrance of entrance hood of entrance hood section 4B. The entrance hood section 4A is a new tunnel entrance hood that is extended to an existing or new tunnel entrance hood. As shown in FIGS. 2 and 4, the entrance hood portion 4A has a cross-sectional area A _{h '} larger than that of the entrance hood portion 4B. The entrance hood 4B is a second-stage tunnel entrance hood that covers the tunnel portal 3a. The entrance hood section 4B is an existing tunnel entrance hood or a new tunnel entrance hood covering the tunnel portal 3a. As shown in FIGS. 2 and 4, the entrance hood 4B has a cross-sectional area _Ah larger than the cross-sectional area A of the tunnel 3 . The entrance hood section 4B is constructed between the tunnel 3 and the entrance hood section 4A continuously. Here, the cross-sectional areas A _h and A _h ' are the areas of the cut surfaces of the entrance hoods 4A and 4B when cut along a plane perpendicular to the center line of the hoods 4A and 4B.

The micro-pressure wave reducing structure 5 shown in FIGS. 1 to 4 is a structure for reducing the tunnel micro-pressure wave W ₂ radiated from the tunnel entrance 4a of the tunnel entrance 4 covering the tunnel entrance 3a. As shown in FIGS. 1 and 24, the micro-pressure wave reducing structure 5 reduces the tunnel micro-pressure wave _W2 emitted from the tunnel portal 3b on the opposite side when the train 1 rushes into the tunnel portal 3a. While maintaining the reduction performance, the tunnel micro-pressure wave _W2 emitted from the entrance 4a of the tunnel entrance hood 4 when the train 1 rushes into the tunnel entrance 3b on the opposite side as shown in FIGS. 3 and 25 is also reduced. do. The micro-pressure wave reducing structure 5 includes a radiation section 6 shown in FIGS. 1 to 4 and the like.

The radiation section 6 opens a part of the tunnel entrance hood 4 in order to reduce the tunnel micro-pressure wave _W2 radiated from the entrance hood 4a when the train 1 rushes into the tunnel entrance 3b on the opposite side. , which radiates part of this tunnel micro-pressure wave _W2 to the outside. As shown in FIGS. 2 and 4, the radiating portion 6 is formed at a stepped portion (cross-sectional area changing portion) where the cross-sectional areas A _h ' and A _h of the entrance hoods 4A and 4B change. As shown in FIGS. 1 to 4, the radiating portion 6 is arranged parallel to the center line of the tunnel entrance hood 4, and extends linearly along the longitudinal direction of the tunnel entrance 4 with a predetermined length. formed. Radial portion 6 is a wall portion formed by extending the end portion of tunnel entrance 3a side of entrance hood portion 4A and forming a predetermined space outside of entrance hood portion 4B. The radiating section 6 is provided at the entrances _of the tunnel hood sections _4A and 4B shown in FIG. By opening the step portion, the tunnel micro-pressure wave _W22 shown in FIG. 3, which is part of the tunnel micro-pressure wave _W2 shown in FIG. 25, is radiated to the outside. As shown in FIGS. 2 and 4, the radiation section 6 includes an opening 6a, a passing section 6b, an opening 6c, and the like.

The opening 6a shown in FIGS. 2 and 4 is a portion that allows part of the compression wave _W1 propagating from the tunnel portal 3a to enter the passage 6b from the tunnel entrance hood 4. As shown in FIG. The opening 6a is formed at the end of the passage portion 6b on the side of the entrance hood 4a so as to face the entrance 4a. It is formed between the end on the side of the engineering mouth 4a. The opening 6a is an opening of the end surface obtained by removing the vertical walls forming the stepped portion between the entrance hood 104A and the entrance hood 104B of the conventional tunnel entrance hood 104 shown in FIG. is. The opening 6a functions as an entrance-side opening that allows the compression wave _W12 , which is a part of the compression wave _W1 propagating from the tunnel 3 to the tunnel entrance hood 4, to enter the passage 6b.

A passing portion 6b shown in FIGS. 2 and 4 is a portion through which a portion of the compression wave _W1 propagating from the tunnel portal 3a passes. The passing portion 6b functions as a duct that guides the compression wave _W12 , which is a part of the compression wave _W1 entering from the opening 6a, to the opening 6c. The passage portion 6b extends the entrance hood portion 4A to the outside of the entrance hood portion 4B as shown in FIGS. 1 to 4, and as shown in FIG. It is a structure that forms a part. The passing portion 6b is constructed to extend from the stepped portions of the entrance hoods 4A and 4B toward the tunnel portal 3a.

The opening 6c shown in FIGS. 2 and 4 is a portion through which part of the compression wave _W1 propagating from the tunnel portal 3a is radiated from the passing portion 6b. The opening 6c is formed at the end of the passing portion 6b on the side of the tunnel portal 3a. The opening 6c functions as an exit side opening for radiating the compression wave _W12 , which is a part of the compression wave _W1 propagating from the tunnel 3 to the tunnel entrance hood 4, to the outside from the passage 6b.

Next, the operation of the micro-pressure wave reducing structure for tunnel entrance hoods according to the first embodiment of the present invention will be described.
(Performance during radiation)
As shown in FIG. 8(A), when the train 1 traveling in the direction opposite to the train 1 shown in FIG. A compression wave W ₁ is generated in the tunnel ₃ and propagates through the tunnel 3 . As shown in FIG. 3, a part of the compression wave _W11 of the compression wave _W1 propagating from the tunnel 3 to the tunnel entrance hood 4 propagates from the tunnel entrance 3a to the entrance hood 4a, and then from the entrance 4a to the outside. The tunnel micro-pressure wave _W21 radiates to A part of the compression wave _W12 of the compression wave _W1 propagating from the tunnel 3 to the tunnel entrance hood 4 is propagated from the tunnel portal 3a to the opening 6c, and the tunnel micro-pressure wave _W22 is transmitted from the opening 6c to the outside. radiates.

Tunnel micro-pressure waves _W21 and _W22 , which are smaller than the tunnel micro-pressure wave _W2 emitted from the tunnel entrance hood 4, are radiated to the outside from two locations, the entrance hood 4a and the opening 6c, and the tunnel micro-pressure waves Wave _W2 is dispersed. When considering measuring two tunnel micro-pressure waves W ₂₁ and W ₂₂ near the entrance hood 4a, the measurement points of the two tunnel micro-pressure waves W ₂₁ and W ₂₂ increase as the passing section 6b becomes longer. Since the difference in the arrival time to the point is increased, the peak values of the two tunnel micro-pressure waves W ₂₁ and W ₂₂ are shifted, and even if the two overlap, the maximum value does not increase.

(Rush performance)
As shown in FIG. 8(B), when the train 1 enters the tunnel entrance 3a where the tunnel entrance hood 4 is installed, the difference in level between the entrance hood 4a, the entrance hood section 4A and the entrance hood section 4B A compression wave _W1 is generated when the head of the train 1 sequentially passes through the steps between the entrance hood 4B and the tunnel 3. As shown in FIG. When the generated compression wave _W1 propagates toward the tunnel 3, each compression wave _W1 is reflected at each stepped portion, the radiation portion 6, and the entrance hood 4a. W ₁ reciprocates and each compression wave W ₁ overlaps.

Since the degree of superimposition of each compression wave _W1 changes depending on the length _Lh3 of the radiating portion 6, the peak values of the pressure gradients of the compression waves _W1 deviate from each other, resulting in a pressure gradient (time change of the compression wave _W1 The magnitude of the peak value (corresponding to the tunnel micro-pressure wave _W2 ) changes. As a result, the tunnel micro-pressure wave _W2 radiated to the outside from the tunnel _entrance 3b on the opposite side changes. The performance is maintained at the same level as the micro pressure wave reduction effect when rushing.

The micro-pressure wave reducing structure for tunnel entrance hoods according to the first embodiment of the present invention has the following effects.
(1) In this first embodiment, part of the tunnel entrance hood 4 is opened in order to reduce the tunnel micro-pressure wave _W2 shown in FIG. 25 when the train 1 rushes into the tunnel portal 3b on the opposite side. Then, a portion of this tunnel micro-pressure wave W ₂ is radiated outside by the radiating section 6 . For this reason, as shown in FIG. 1, while maintaining the micro-pressure wave reduction performance against the train 1 entering the tunnel portal 3a, the train 1 running in the opposite direction as shown in FIGS. It is also possible to reduce the tunnel micro-pressure wave _W2 emitted when entering the wellhead 3b. For example, as shown in FIG. 25, when the train 1 rushes into the tunnel portal 3b on the opposite side, the tunnel micro-pressure wave _W2 emitted from the tunnel portal 3a is changed to the tunnel micro-pressure wave W ₂₁ and wave W ₂₂ , and radiated from the entrance hood 4 a and the radiation section 6 . As a result, the tunnel micro-pressure wave _W2 emitted from the entrance hood 104a shown in FIG. 25 can be reduced. Further, when the train 1 rushes into the tunnel portal 3a, the reduction performance of the tunnel micro-pressure wave _W2 radiated from the tunnel portal 3b on the opposite side can be maintained. As a result, countermeasures for reducing micro-pressure waves at the tunnel portal 3b on the opposite side are unnecessary or can be reduced, and costs can be reduced. Performance can also be improved.

(2) In the first embodiment, the tunnel entrance 3a is covered with the tunnel entrance hoods 4A and 4B so that the cross-sectional area of the tunnel entrance 4 increases stepwise from the tunnel entrance 3a toward the entrance hood 4a. , the stepped portions of the entrance hoods 4A and 4B are opened, and the radiation portion 6 radiates a part of the tunnel micro-pressure wave _W2 to the outside. Therefore, by removing the vertical walls forming the stepped portions of the entrance hood sections 4A and 4B of the conventional tunnel entrance hood 104 shown in FIG. The tunnel micro-pressure wave _W2 can be easily reduced. For example, when there is an existing two-stage entrance hood as shown in Fig. 24, and when the speed of Shinkansen trains increases and travels at a higher speed, the opening construction of the vertical wall of the existing two-stage entrance hood and installing a new rear end wall in the 2-stage entrance hood, the tunnel micro-pressure wave _W2 can be reduced at a relatively low cost.

(Second embodiment)
1 to 8 are denoted by the same reference numerals, and detailed description thereof will be omitted.
In this second embodiment, the speed U of the train 1 shown in FIGS _. 2.5 to 3.2, the total length L _h1 of the entrance hood 4A is 20 _m or more, the cross-sectional area ratio σ _h of the entrance hood 4B is 1.4 to 1.5, the entrance hood 4B It is preferable to set the total length L _h2 to 20 m or more and the length L _h3 of the radiation portion 6 to 20 to 40 m. Here, the cross-sectional area ratio σ _h ' is the ratio A _h '/A of the cross-sectional area A _h ' of the entrance hood 4A to the cross-sectional area A of the tunnel 3 . The cross-sectional area ratio σ _h is the ratio _Ah / _A of the cross-sectional area Ah of the entrance hood 4B to the cross-sectional area A of the tunnel 3 . The cross-sectional area A is the area of the cut surface of the main hole of the tunnel 3 when cut along a plane orthogonal to the center line of the tunnel 3 . This second embodiment has the same effect as the first embodiment.

(Third embodiment)
In this third embodiment, when the Mach number of the train 1 is M and the total length of the entrance hood 4B is L _h2 , the sectional area ratio σ _h ′ of the entrance hood 4A shown in FIG. Total length of hood 4A L _h1 >L _W0 ·M/(1−M), Cross-sectional area ratio σ _h of hood 4B ≈1.4 to 1.5, Total length of hood 4B L _h2 ≧L _h1 , Radiation 6 It is preferable to set the length L _h3 ≈0.6L _W0 . Here, the wave front width L _W0 shown in FIG. 7(A) is the compression wave W The wavefront width of _1≈√A /M. This third embodiment has the same effect as the first embodiment.

(Fourth embodiment)
In this fourth embodiment, the speed U of the train 1 shown in FIGS _. 6, the cross-sectional area ratio σ _h ≈2.5 to 3.2 of the entrance hood 4A, the total length L _h1 of the entrance hood 4A is 20 m or more, the cross-sectional area ratio σ _h ≈1.4 to 1.5 of the entrance hood 4B, and the entrance hood 4B It is preferable to set the total length L _h2 of 20 m or more and the length L _h3 of the radiation portion 6 to 15 to 25 m. This fourth embodiment has the same effect as the first embodiment.

(Fifth embodiment)
In this fifth embodiment, when the Mach number of the train 1 is M, the cross-sectional area ratio σ _{h ′} of the entrance hood 4A shown in _FIG . M/(1−M), cross-sectional area ratio σ _h of entrance hood 4B ≈1.4 to 1.5, total length of entrance hood 4B L _h2 ≧L _h1 , length of radiating portion 6 L _h3 ≈0.35 to 0.4L _W0 It is preferable to set This fifth embodiment has the same effect as the first embodiment.

(Sixth embodiment)
The radial portion 6 shown in FIG. 9(A) is arranged obliquely upward with respect to the center line of the tunnel entrance hood 4, and extends linearly to a predetermined length across the length direction of the tunnel entrance hood 4. is formed by The radial part 6 shown in FIG. 9(B) is arranged in a direction perpendicular to the center line of the tunnel entrance hood 4, and extends linearly for a predetermined length perpendicular to the length direction of the tunnel entrance hood 4. is formed by The radial portion 6 shown in FIG. 9 is formed in a smooth curve at the portion where the entrance hoods 4A, 4B and the opening 6a are connected. The radiating portion 6 shown in FIG. 9 has a cross-sectional area when cut along a plane orthogonal to the center line of the radiating portion 6, which is a plane orthogonal to the center line of the radiating portion 6 shown in FIGS. It is set to be the same as the cross-sectional area when cut with This sixth embodiment has the same effects as those of the first to fifth embodiments.

(Seventh embodiment)
The micro-pressure wave reduction structure 5 shown in FIGS. 10 and 11 performs optimization control of the radiation section 6 by opening and closing the radiation section 6 according to the direction of travel D ₁ and D ₂ of the train 1, thereby reducing tunnel micro-pressure waves. Reduce the pressure wave _W2 . The micro-pressure wave reducing structure 5 includes train detection units 7A and 7B, an opening/closing unit 8, a driving unit 9, an opening/closing state detection unit 10, a control unit 11, and the like. The radiation portion 6 shown in FIGS. 10 and 11 differs from the radiation portion 6 shown in FIGS. 1 to 4, FIG. 6A, FIG. 8 and _FIG . is set and has an opening 6a. The opening 6a is a portion that radiates part of the compression wave _W1 propagating from the tunnel portal 3a. The opening 6a radiates a compression wave W12, which is a part of the compression wave _W1 propagating from the tunnel 3 to the tunnel entrance hood ₄ , to the outside.

The train detection units 7A and 7B are means for detecting the train 1. FIG. The train detector 7A is installed in front of the entrance hood 4a and detects the train 1 approaching the entrance 4a. The train detection unit 7B is installed in front of the tunnel portal 3b on the opposite side, and detects the train 1 approaching the tunnel portal 3b. The train detection units 7A and 7B are detection devices such as sensors that electrically or optically detect passage of the train 1, for example. The train detection units 7A and 7B output a train detection signal to the control unit 11 when the passage of the train 1 is detected.

The opening/closing part 8 is means for opening and closing the radiation part 6 . As shown in FIG. 11(A), the opening/closing section 8 closes the radial section when the train 1 rushes into the entrance hood 4a, and as shown in FIG. , the radiation part 6 is opened. The opening/closing part 8 is, for example, an opening/closing device such as an opening/closing plate or a shutter for opening/closing the opening 6a of the radiation part 6 . A drive unit 9 shown in FIGS. 10 and 11 is means for driving the opening/closing unit 8 . The driving unit 9 is, for example, a driving force generating device such as a fluid pressure cylinder or an electric motor that generates a driving force for opening and closing the opening/closing unit 8 . The open/close state detector 10 is means for detecting the open/close state of the radiation unit 6 . The open/closed state detection unit 10 is a detection device such as a sensor that detects the open state or closed state of the radiation unit 6 by mechanically, electrically, or optically detecting the open/closed position of the open/close unit 8, for example. The open/close state detection unit 10 outputs an open/close state detection signal to the control unit 11 according to the open/close state of the radiation unit 6 .

The control unit 11 is means for controlling the drive unit 9 based on the detection results of the train detection units 7A and 7B. As shown in FIG. 11(A), the control unit 11 instructs the driving unit 9 so that the opening/closing unit 8 closes the radiation unit 6 based on the train detection signal output from the train detection unit 7A. As shown in FIG. 11(B), the control unit 11 instructs the driving unit 9 so that the opening/closing unit 8 opens the radiation unit 6 based on the train detection signal output from the train detection unit 7B. Based on the open/close state detection signal output from the open/close state detection unit 10 , the control unit 11 instructs the drive unit 9 so that the opening/closing unit 8 opens and closes the radiation unit 6 .

Next, a micro-pressure wave reducing structure for tunnel entrance hoods according to a seventh embodiment of the present invention will be described.
As shown in FIG. 11A, when the train 1 approaches the entrance hood 4a, the train detector 7A detects the approach of the train 1 and outputs a train detection signal to the controller 11. . The open/closed state detection unit 10 detects the open/closed state of the radiation unit 6, and the open/closed state detection unit 10 outputs an open/closed state signal to the control unit. When the control section 11 determines that the radiation section 6 is opened by the opening/closing section 8 , it commands the driving section 9 to close the radiation section 6 so that the opening/closing section 8 closes the radiation section 6 . As a result, the train 1 rushes into the tunnel portal 3a in a state in which the opening and closing section 8 rotates and the radiation section 6 is closed, and the tunnel micro-pressure wave _W2 radiated from the tunnel portal 3b on the opposite side is generated by the tunnel entrance hood. reduced by 4.

On the other hand, as shown in FIG. 11(B), when the train 1 approaches the tunnel portal 3b on the opposite side, the approach of the train 1 is detected by the train detection unit 7B, and the train detection unit 7B outputs the train detection signal to the control unit. 11. The open/closed state detection unit 10 detects the open/closed state of the radiation unit 6, and the open/closed state detection unit 10 outputs an open/closed state signal to the control unit. When the control section 11 determines that the radiation section 6 is closed by the opening/closing section 8 , it commands the driving section 9 to open the radiation section 6 so that the opening/closing section 8 opens the radiation section 6 . As a result, the train 1 rushes into the tunnel portal 3b on the opposite side in a state where the opening and closing section 8 rotates and the radiation section 6 is opened, and a part of the tunnel micro-pressure wave _W21 is radiated from the entrance hood 4a. A portion of the tunnel micro-pressure wave W ₂₂ is radiated from the opening 6a. As a result, tunnel micro-pressure waves W ₂₁ and W ₂₂ radiate from two locations, the entrance hood 4a and the opening 6a shown in FIGS. 10 and 11, and the tunnel micro-pressure wave W ₂ shown in FIG. 25 is dispersed, The tunnel micro-pressure wave _W2 is reduced.

The micro-pressure wave reducing structure for a tunnel entrance hood according to the seventh embodiment of the present invention has the following effects in addition to the effects of the first to sixth embodiments.
In this seventh embodiment, when the train 1 rushes into the entrance hood 4a, the radiation section 6 is closed by the opening/closing section 8, and when the train 1 rushes into the tunnel portal 3b on the opposite side, the radiation section 6 is closed by the opening/closing section. 8 opens. The length L _h3 of the radiating section 6 should be about 20m for the performance when the train 1 rushes into the tunnel entrance hood 4, but when the train 1 rushes into the tunnel portal 3b on the opposite side, From the performance point of view, the length L _h3 of the radiating portion 6 needs to be 0 m or about 40 m. Therefore, in the case of a structure in which the opening/closing portion 8 does not open and close the radiation portion 6, the length L _h3 of the radiation portion 6 needs to be 40 m in order to ensure both the performance at the time of entry and the performance at the time of radiation. As a result, the length _Lh3 of the radiating portion 6 becomes very long, and the merit of cost reduction is diminished. In this seventh embodiment, when the train 1 rushes into the entrance hood 4a, the opening 6a is closed by the opening/closing part 8, and the tunnel entrance hood 4 becomes a double-level entrance hood. As a result, the passage portion 6b of the _radiation portion 6 becomes unnecessary, and the cost can be reduced. can. Further, in the seventh embodiment, when the train 1 rushes into the tunnel portal 3b on the opposite side, the performance during radiation can be ensured even if the length _Lh3 of the radiation section 6 is 0 m. For this reason, the passage portion 6b _of the radiation portion 6 becomes unnecessary _, and a cost reduction effect can be achieved. The tunnel micro-pressure wave _W2 can be dispersed and reduced.

(Eighth embodiment)
The micro-pressure wave reducing structure 5 shown in FIGS. 12 and 13 optimizes control of the radiation section 6 by changing the length L _h3 of the radiation section 6 according to the traveling directions D ₁ and D ₂ of the train 1. to reduce the tunnel micro-pressure wave _W2 . The micro-pressure wave reducing structure 5 includes train detection units 7A and 7B, a length variable unit 12, a position detection unit 13, a control unit 14, and the like.

The radiation section 6 has a structure that can be joined to and separated from the tunnel entrance hood 4 . The radiating portion 6 joins and separates at the stepped portion between the hood hood portion 4A and the hood hood portion 4B. As shown in FIG. 13(A), when the train 1 rushes into the entrance hood 4a, the radiation part 6 is attached to the end of the tunnel entrance 3a side of the entrance hood 4A. side ends connect. As shown in FIG. 13B, when the train 1 rushes into the tunnel portal 3b on the opposite side, the radial section 6 extends from the end of the tunnel portal 3a side of the entrance hood 4A. The end on the mouth 4a side is separated.

The length variable portion 12 shown in FIGS. 12 and 13 is means for varying the length _Lh3 of the radiation portion 6. As shown in FIG. As shown in FIG. 13(A), when the train 1 rushes into the entrance hood 4a, the length variable section 12 changes the length _Lh3 of the radiation section 6 to a predetermined length. As shown, when the train 1 rushes into the tunnel portal 3b on the opposite side, the length _Lh3 of the radiating portion 6 is set to zero. As shown in FIG. 13(A), the variable length portion 12 is formed by joining the radiation portion 6 to the entrance hood portion 4A and adjusting the length _Lh3 of the radiation portion 6 to a predetermined length. drive. As shown in FIG. 13B, the variable length section 12 separates the radiation section 6 from the hood 4A and drives the radiation section 6 so that the length _Lh3 of the radiation section 6 becomes zero. . The variable length part 12 is, for example, a driving force generating device such as a fluid pressure cylinder or an electric motor that generates a driving force for driving the radial part 6 so that the radial part 6 is connected to and separated from the tunnel entrance hood 4. be.

A position detection unit 13 shown in FIGS. 12 and 13 is means for detecting the position of the radiation unit 6 . The position detection part 13 detects the connection position where the radiation part 6 is located when the radiation part 6 is connected to the tunnel entrance hood 4 as shown in FIG. A separation position where the radiation section 6 is positioned when the radiation section 6 is separated from the radiation section 4 is detected. The position detection unit 13 is a detection device such as a sensor that mechanically, electrically, or optically detects whether or not the radiation unit 6 is at the connected position or the separated position. The position detection section 13 outputs a connection position detection signal or a separation position detection signal to the control section 14 according to the position of the radiation section 6 .

The control section 14 shown in FIGS. 12 and 13 is means for controlling the length varying section 12 based on the detection results of the train detection sections 7A and 7B. As shown in FIG. 13A, based on the train detection signal output from the train detection unit 7A, the control unit 14 connects the radiation unit 6 to the tunnel entrance hood 4 so that the length L _h3 of the radiation unit 6 is adjusted. The variable length section 12 is instructed to drive the radiation section 6 so as to obtain a predetermined length. As shown in FIG. 13B, based on the train detection signal output from the train detection unit 7B, the control unit 14 separates the radiation unit 6 from the tunnel entrance hood 4 so that the length L _h3 of the radiation unit 6 is increased. The variable length unit 12 is instructed to drive the radiation unit 6 so that the value becomes zero. Based on the position detection signal output from the position detection section 13, the control section 14 instructs the length varying section 12 to vary the length _Lh3 of the radiation section 6. FIG.

Next, a micro-pressure wave reducing structure for tunnel entrance hoods according to an eighth embodiment of the present invention will be described.
As shown in FIG. 13A, when the train 1 approaches the entrance hood 4a, the train detector 7A detects the approach of the train 1 and outputs a train detection signal to the controller 14. . When the position detection section 13 detects that the radiation section 6 is at the separated position, the position detection section 13 outputs a separated position detection signal to the control section 14 . When the control unit 14 determines that the position of the radiation part 6 is the separated position and that the radiation part 6 is separated from the tunnel entrance hood 4, the length _Lh3 of the radiation part 6 becomes a predetermined length. A joining operation is commanded to the length variable section 12 . As a result, the train 1 rushes into the tunnel portal 3a in a state where the radial section 6 is connected to the tunnel entrance hood 4 and the length _Lh3 of the radial section 6 becomes a predetermined length, and the train 1 enters the tunnel portal 3b on the opposite side. The radiating tunnel micro-pressure wave W ₂ is reduced by the tunnel entrance hood 4 .

On the other hand, as shown in FIG. 13(B), when the train 1 approaches the tunnel portal 3b on the opposite side, the approach of the train 1 is detected by the train detection unit 7B, and the train detection unit 7B outputs the train detection signal to the control unit. 14. When the position detection section 13 detects that the position of the radiation section 6 is the connection position, the position detection section 13 outputs a connection position detection signal to the control section 14 . The position of the radiation part 6 is the connection position, and when the control part 14 determines that the radiation part 6 is connected to the tunnel entrance hood 4, the length L _h3 of the radiation part 6 becomes zero. The variable unit 12 is instructed to perform a separation operation. As a result, the train 1 rushes into the tunnel portal 3b on the opposite side in a state in which the radiation section 6 is separated from the tunnel entrance hood 4 and the length _Lh3 of the radiation section 6 becomes zero, and a portion of the tunnel micropressure A wave _W21 is radiated from the entrance hood 4a, and a part of the tunnel micro-pressure wave _W22 is radiated from the opening 6c. As a result, tunnel micro-pressure waves W ₂₁ and W ₂₂ radiate from two locations, the entrance hood 4a and the opening 6c shown in FIGS. 12 and 13, and the tunnel micro-pressure wave W ₂ shown in FIG. 25 is dispersed, The tunnel micro-pressure wave _W2 is reduced.

The micro-pressure wave reducing structure for a tunnel entrance hood according to the eighth embodiment of the present invention has the following effects in addition to the effects of the first to sixth embodiments.
In this eighth embodiment, when the train 1 rushes into the entrance hood 4a, the length _Lh3 of the radiation part 6 is changed to a predetermined length by the length variable part 12, and the train 1 moves into the tunnel entrance 3b on the opposite side. , the length variable section 12 changes the length L _h3 of the radiation section 6 to zero. From the radiation performance when the train 1 rushes into the tunnel entrance 3b on the opposite side, there is an effect even if the length L _h3 of the radiation part 6 is 0 m, but the performance when the train 1 rushes into the tunnel entrance hood 4 The length L _h3 of the radiating portion 6 is required to be approximately 20 m. In this eighth embodiment, when the train 1 enters the tunnel entrance hood 4, the length _Lh3 of the radiation part 6 is about 20 m. It is possible to make a structure in which the length _Lh3 of the radiating portion 6 is 0 m by shifting. Therefore, when the train 1 rushes into the entrance hood 4a, the tunnel entrance hood 4 can reduce the tunnel micro-pressure wave _W2 emitted from the tunnel entrance 3b on the opposite side. Also, when the train 1 enters the tunnel portal 3b on the opposite side, the tunnel micro-pressure waves _W2 are dispersed and radiated from two locations, the entrance hood 4a and the opening 6c, to reduce the tunnel micro-pressure waves _W2 . be able to.

Next, an embodiment of the invention will be described.
A model experiment was conducted to confirm the effect of the micro-pressure wave reducing structure of the tunnel entrance hood according to the embodiment of the present invention. Using the tunnel micro-pressure wave model test equipment of the Railway Technical Research Institute shown in Fig. 14, a vehicle model was driven into the entrance hood model, and two pressure gauges were installed at a position of 1m from the entrance of the tunnel model. The waveform of the compression wave _W1 in the tunnel model was measured by (pressure transducer P). In order to measure the speed of the vehicle model, a coil was installed at a distance of 4 m. The pressure gradient waveform was obtained by central difference. A semiconductor pressure transducer (model: XCS-190-5G) manufactured by kulite was used as a pressure gauge.

In the model test, axisymmetric models were used for the vehicle, tunnel, and tunnel entrance hood, and the running position was only center running with the central axis of the vehicle and tunnel aligned, and the vehicle speed was 320km/h and 360km/h. bottom. The effect of the ground is simulated by the mirror image method, and the scale is about 1/127. The vehicle/tunnel cross-sectional area ratio was set at 0.19, which is equivalent to the Shinkansen. The shape of the head part is a spheroid, and its length is equivalent to 15m on the actual scale. The main specifications of the model used in the model experiment are shown in Table 1 below.

(Rush performance)
The performance at the time of rushing into the entrance hood of the entrance hood model shown in FIG. 15 was confirmed. FIG. 15 is a schematic diagram of the entrance hood model used in the tunnel micro-pressure wave model experimental device shown in FIG. The proposed entrance hood shown in FIG. 15(A) is a hood hood model according to an embodiment that simulates the tunnel entrance hood 4 provided with the micro-pressure wave reducing structure 5 shown in FIGS. This is an open end end type two-stage entrance hood in which the end end of the joint between the extended part of the conventional two-stage entrance hood and the existing part is opened. The two-stage entrance hood shown in FIG. 15(B) is a tunnel entrance hood model simulating the conventional tunnel entrance hood 104 shown in FIG. 24, and the cross-sectional area is changed in two stages. At the tunnel entrance of the tunnel model of the tunnel micro-pressure wave model experimental device shown in FIG. 14, the proposed entrance hood shown in FIG. 16(A) and the two-stage entrance hood shown in FIG. The compression wave W ₁ in the tunnel model was measured when the tunnel model was opened, and the magnitude of the slope (pressure gradient) of the compression wave W ₁ corresponding to the magnitude of the tunnel micro-pressure wave was compared.

FIG. 17 shows experimental results of the performance during entry when the model test shown in FIG. 15 was conducted for the proposed entrance hood shown in FIG. 16(A) and the two-stage entrance hood shown in FIG. 16(B). The vertical axis shown in FIG. 17 is the pressure gradient maximum value ratio α, and the horizontal axis is the wall length (corresponding to the length L _h3 of the radiation portion 6 shown in FIGS. 2 and 6) (m). Here, the maximum pressure gradient value ratio α is the ratio of the maximum pressure gradient value with the tunnel entrance hood 4 to 1 when the maximum pressure gradient value without the tunnel entrance hood 4 is present. The wall length of the proposed entrance hood shown in FIG. The pressure gradient maximum ratio α of ₁ was measured respectively. Further, the speed of the model vehicle was changed to 320 km/h and 360 km/h for the two-stage entrance hood shown in FIG. 16(B), and the pressure gradient maximum value ratio α of the compression wave _W1 in the tunnel model was measured. As a result, as shown in Fig. 17, the proposed entrance hood can make the pressure gradient (tunnel micro-pressure wave) smaller than the two-stage entrance hood at a wall length of 10 m or more under the conditions equivalent to the current Shinkansen. confirmed.

To generalize the test results of performance during entry, the cross-sectional area ratio σ _h of the entrance hood 6A ≈1.4 to 1.5, the total length of the hood 6A L _h2 ≧L _h1 , and the cross-sectional area ratio σ _h '≈ of the hood 6B 2.5. It was confirmed that under the conditions of total length L _h1 >L _W0 M/(1-M) of entrance hood 6B and length L _h3 of radiation part 6 ≒ 0.35 to 0.40L _W0 , performance at inrush can be improved. was done. Assuming the current Shinkansen train (head length of about 15 m or less, speed of 260 to 360 km/h), total lengths L _h1 and L _h2 of entrance hoods 4A and 4B are 20 m or more, and length L _h3 of radiation part 6 is 15 m. It was confirmed to be about 20m.

(Performance during radiation)
A model train rushed into the tunnel entrance shown in FIG. 18 and the tunnel micro-pressure wave _W2 was radiated from the tunnel entrance of the entrance hood model, and the performance during radiation was confirmed. FIG. 18 is a schematic diagram of the entrance hood model used in the tunnel micro-pressure wave model experimental device shown in FIG. The proposed entrance hood shown in FIG. 18(A) is a hood hood model according to an embodiment simulating the tunnel entrance hood 4 having the micro-pressure wave reducing structure 5 shown in FIGS. It is a two-stage entrance hood of the type. The two-stage entrance hood shown in FIG. 18B is a tunnel hood model simulating the conventional tunnel entrance hood 104 shown in FIG. 25, and the cross-sectional area is changed in two stages. The normal entrance hood shown in FIG. 18(C) is a tunnel entrance hood model simulating the conventional tunnel entrance hood 104 shown in FIG. 22, and has a constant cross-sectional area. The no entrance hood shown in FIG. 18D is a tunnel model simulating the tunnel without the tunnel entrance hood shown in FIG.

At the tunnel exit of the tunnel model of the tunnel micro-pressure wave model experimental device shown in FIG. The tunnel micro-pressure wave _W2 radiated from the tunnel entrance was measured with a microphone installed at the measurement position corresponding to the 40m point when a model train was plunged into the tunnel. In addition, without installing the entrance hood model at the tunnel exit of the tunnel model of the tunnel micro-pressure wave model test device shown in FIG. At that time, the tunnel micro-pressure wave _W2 radiated from the tunnel exit was measured with a microphone installed at the measurement position corresponding to the 40m point. A precision sound level meter (model: NL-32) manufactured by Rion Co., Ltd. was used as a microphone. The proposed entrance hood shown in Figures 18(A) and 19(A) has a wall length of 20 m and a cross-sectional area ratio of the end opening to the main tunnel of 1.1 (0.80 considering the wall thickness). . The microphones shown in FIG. 19 were installed at measurement positions of 30°, 60°, and 90° in the horizontal direction from the center of the tunnel entrance on the center line of the tunnel model along the moving direction of the vehicle model.

Fig. 20 shows the proposed entrance hood shown in Fig. 18(A), the two-stage entrance hood shown in Fig. 18(B), the normal entrance hood shown in Fig. 18(C) and the no entrance hood shown in Fig. 18(D). FIG. 19 shows experimental results of performance during radiation when the model experiment shown in FIG. 19 is conducted. As shown in Fig. 20, when the speed of the model train is 320 km/h and 360 km/h, the tunnel micro-pressure wave _W2 of the proposed entrance hood is smaller than that of the two-stage entrance hood at both measurement positions. confirmed. In addition, it was confirmed that the proposed tunnel hood can reduce the tunnel micro-pressure wave _W2 to the level of the normal hood at the measurement positions other than the measurement position with a radiation angle of 90°.

To generalize the test results of radiation performance, when reducing to the normal entrance hood level (hereinafter referred to as level 1), the length of the radiation part 6 L _h3 > 0.6 L _W0 or L _h3 ≈ 0, 2 In the case of reducing to the step entrance hood level (hereinafter referred to as level 2), it was confirmed that the performance during radiation can be improved under the condition that the length of the radiation portion 6 is L _h3 >0.35L _W0 or L _h3 ≈0. Assuming the current Shinkansen train (head length of about 15 m or less, speed of 260 to 360 km/h), at Level 1, the length L _h3 of the radiation section 6 is 20 m at 260 km/h, 30 m at 320 km/h, and 30 m at 360 km/h. At level 2, the length L _h3 of the radiation section 6 is 15 m at 260 km/h, 20 m at 320 km/h, and 25 m at 360 km/h (sufficient condition).

(Other embodiments)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible as described below, which are also within the scope of the present invention.
(1) In this embodiment, the case where the moving body is the train 1 has been described as an example, but the present invention can also be applied to other moving bodies such as magnetic levitation railways and automobiles. Also, in this embodiment, the case where the fixed structures are the tunnel 3 and the tunnel entrance hood 4 has been described as an example, but the fixed structures are not limited to these. For example, eaves-shaped snow sheds (avalanche protection) that cover the railway from the hillside slope to allow avalanches to pass through, snow shelters that cover the railway to prevent the occurrence of drifts on the railway due to snowstorms and snowstorms, and snow shelters that cover the railway from the slope The present invention can also be applied to a fixed structure such as a rockfall cover (rockfall protection work) that covers a railroad track in order to allow falling or falling rocks to pass through. Furthermore, although the case where the train 1 is a Shinkansen train has been described as an example, a conventional line train that runs on a conventional line, or a train for new direct operation that can run between the Shinkansen and a conventional line The present invention can also be applied to such as.

(2) In this embodiment, the case where the track 2 is a double track has been described as an example, but the present invention can also be applied to a case where the track 2 is a single track or a double track. In this embodiment, the tunnel entrance hood 4 has a semicircular or rectangular cross section, but the cross-sectional shape of the tunnel entrance hood 4 is not limited to these. For example, the present invention can also be applied to polygons such as hexagons. Furthermore, in the sixth embodiment, the case where the radiation section 6 is oriented obliquely upward or linearly in the vertical direction has been described as an example, but the orientation of the radiation section is not limited to these directions. For example, the present invention can be applied to a case in which the radiating portion 6 is oriented linearly or curvedly in any direction.

(3) In the seventh embodiment, before the train 1 rushes into the entrance hood 4a, the opening/closing part 8 closes the opening 6a, and before the train 1 rushes into the tunnel portal 3b on the opposite side, the opening/closing part 8 opens and closes. Although the case where the portion 8 opens the opening portion 6a has been described as an example, the present invention is not limited to such opening/closing timing. For example, when the train 1 entering the entrance hood 4a exits from the tunnel entrance 3b on the opposite side, the opening/closing part 8 may open the opening 6a, or the train 1 entering the tunnel entrance 3b on the opposite side may be buffered. The present invention can also be applied to the case where the opening/closing portion 8 closes the opening portion 6a when exiting from the engineering mouth 4a. Similarly, in this eighth embodiment, before the train 1 rushes into the entrance hood 4a, the radiation section 6 is connected to the tunnel entrance hood 4 by the length variable section 12, and the train 1 is connected to the tunnel entrance 3b on the opposite side. Although the case where the length variable part 12 separates the radiation part 6 from the tunnel entrance hood 4 before the tunnel entrance hood 4 rushes in has been described as an example, the present invention is not limited to such opening/closing timing. For example, when the train 1 rushing into the entrance hood 4a exits from the tunnel entrance 3b on the opposite side, the radiation part 6 is separated from the tunnel entrance hood 4 by the length variable part 12, or the tunnel entrance 3b on the opposite side is moved. The present invention can also be applied to the case where the radiation part 6 is connected to the tunnel entrance hood 4 by the length variable part 12 when the train 1 rushing into the tunnel exits from the entrance hood 4a.

(4) In the eighth embodiment, the case where the length variable portion 12 connects and separates the radiation portion 6 from the tunnel entrance hood 4 to vary the length L _h3 of the radiation portion 6 will be described as an example. However, the present invention can also be applied to the case where the length variable portion 12 moves the radiation portion 6 back and forth with respect to the tunnel entrance hood 4 to vary the length L _h3 of the radiation portion 6 . For example, the length variable part 12 of the radiation part 6 is advanced from the tunnel entrance hood 4 to set the length L _h3 of the radiation part 6 to a predetermined length, and the radiation part 6 is moved to the tunnel entrance hood 4 and the length variable part 12 is retracted. It is also possible to set the length _Lh3 of the radiating portion 6 to zero. In addition, in the seventh and eighth embodiments, the case where the train detection units 7A and 7B electrically or optically detect the passage of the train 1 has been described as an example. The present invention can also be applied when the train detection units 7A and 7B detect the passage of the train 1 based on the position information of the operation management system.

1 train (mobile)
2 track 3 tunnel 3a tunnel portal (tunnel portal)
3b Tunnel portal (opposite tunnel portal)
4 tunnel entrance hood 4A entrance hood (first entrance hood)
4B entrance hood (second hood)
4a Entrance hood 4c Side (wall)
4d top (wall)
5 micro-pressure wave reducing structure 6 radiation section 6a opening 6b passage section 6c opening 7A, 7B train detection section 8 opening/closing section 9 driving section 10 opening/closing state detection section 11 control section 12 length variable section 13 position detection section 14 control section U train speed (vehicle speed)
L _n Head length L _W0 Wave front width of compression wave L _h1 Overall length of entrance hood (full length of 1st entrance hood)
L _h2 total length of entrance hood (total length of 2nd entrance hood)
L length of _h3 radiation part (predetermined length)
A Cross-sectional area of tunnel A _h ' Cross-sectional area of entrance hood (cross-sectional area of first entrance hood)
A _h Cross-sectional area of entrance hood (cross-sectional area of second entrance hood)
σ _h ' Cross-sectional area ratio of entrance hood (cross-sectional area ratio of first entrance hood)
σ _h Cross-sectional area ratio of entrance hood (cross-sectional area ratio of second entrance hood)
W ₁ compression wave (in-tunnel compression wave)
_W2 Tunnel Micro-Pressure Wave _W21 , _W22 Tunnel Micro-Pressure Wave (Part of Tunnel Micro-Pressure Wave _W2 )

Claims (8)

A micro-pressure wave reducing structure for reducing tunnel micro-pressure waves emitted from a tunnel entrance hood covering a tunnel portal,
In order to reduce the tunnel micro-pressure waves radiated from the tunnel entrance when a moving body rushes into the tunnel entrance on the opposite side, a part of the tunnel entrance hood is opened to reduce the tunnel micro-pressure waves. having a radiating part that radiates to the outside,
A micro-pressure wave reduction structure characterized by In the micropressure wave reducing structure according to claim 1,
The tunnel entrance hood has a hood covering the tunnel portal such that the cross-sectional area of the tunnel hood increases stepwise from the tunnel portal toward the tunnel portal,
The radiating section opens a stepped portion of the entrance hood to radiate a part of the tunnel micro-pressure wave to the outside;
A micro-pressure wave reduction structure characterized by In the micropressure wave reducing structure according to claim 1 or claim 2,
The tunnel entrance hood has first and second hoods in order from the tunnel portal to the tunnel portal such that the cross-sectional area of the tunnel entrance hood increases stepwise from the tunnel portal to the tunnel portal. with a hood of
The speed of the moving body is 260 to 360 km/h, the length of the leading end of the moving body is 15 m or less, the cross-sectional area of the tunnel is A, the cross-sectional area of the first entrance hood is A _h ', the length of the first hood is When the cross-sectional area ratio σ _h '=A _h '/A, the cross-sectional area A _h of the second entrance hood, and the cross-sectional area ratio σ _h of the second hood hood = A _h /A,
Cross-sectional area ratio σ _h ≉2.5 to 3.2 of the first entrance hood, total length of the first entrance hood is 20 m or more, cross-sectional area ratio σ _h of the second hood ≅1.4 to 1.5, the above The total length of the second entrance hood is 20 m or more, and the length of the radiating part is 20 to 40 m,
A micro-pressure wave reduction structure characterized by In the micropressure wave reducing structure according to claim 1 or claim 2,
The tunnel entrance hood has first and second hoods in order from the tunnel portal to the tunnel portal such that the cross-sectional area of the tunnel entrance hood increases stepwise from the tunnel portal to the tunnel portal. with a hood of
The Mach number M of the moving body, the cross-sectional area A of the tunnel, and the wave front width L _W0 of the compression wave generated in the tunnel without the tunnel entrance hood when the moving body enters the tunnel. , the cross-sectional area of the first hood hood A _h ', the cross-sectional area ratio of the first hood hood σ _h '=A _h '/A, the total length L _h1 of the first hood hood, the first Cross-sectional area A _h of the hood 2, cross-sectional area ratio σ _h =A _h /A of the second hood, total length L _h2 of the second hood, and length L _h3 of the radial portion when
Cross-sectional area ratio σ _h ' of the first entrance hood ≈2.5 to 3.2, total length of the first entrance hood L _h1 >L _W0 ·M/(1−M), ratio of the second hood hood The cross-sectional area ratio σ _h ≈1.4 to 1.5, the total length L _h2 ≧L _h1 of the second entrance hood, and the length L _h3 ≈0.6 L _W0 of the radiating portion,
A micro-pressure wave reduction structure characterized by In the micropressure wave reducing structure according to claim 1 or claim 2,
The tunnel entrance hood has first and second hoods in order from the tunnel portal to the tunnel portal such that the cross-sectional area of the tunnel entrance hood increases stepwise from the tunnel portal to the tunnel portal. with a hood of
The speed of the moving body is 260 to 360 km/h, the length of the leading end of the moving body is 15 m or less, the cross-sectional area of the tunnel is A, the cross-sectional area of the first entrance hood is A _h ', the length of the first hood is When the cross-sectional area ratio σ _h '=A _h '/A, the cross-sectional area A _h of the second entrance hood, and the cross-sectional area ratio σ _h of the second hood hood = A _h /A,
Cross-sectional area ratio σ _h ≉2.5 to 3.2 of the first entrance hood, total length of the first entrance hood is 20 m or more, cross-sectional area ratio σ _h of the second hood ≅1.4 to 1.5, the above The total length of the second entrance hood is 20 m or more, and the length of the radiating part is 15 to 25 m,
A micro-pressure wave reduction structure characterized by In the micropressure wave reducing structure according to claim 1 or claim 2,
The tunnel entrance hood has first and second hoods in order from the tunnel portal to the tunnel portal such that the cross-sectional area of the tunnel entrance hood increases stepwise from the tunnel portal to the tunnel portal. with a hood of
The Mach number M of the moving body, the cross-sectional area A of the tunnel, and the wave front width L _W0 of the compression wave generated in the tunnel without the tunnel entrance hood when the moving body enters the tunnel. , the cross-sectional area of the first hood hood A _h ', the cross-sectional area ratio of the first hood hood σ _h '=A _h '/A, the total length L _h1 of the first hood hood, the first Cross-sectional area A _h of the hood 2, cross-sectional area ratio σ _h =A _h /A of the second hood, total length L _h2 of the second hood, and length L _h3 of the radial portion when
Cross-sectional area ratio σ _h ' of the first entrance hood ≈2.5 to 3.2, total length of the first entrance hood L _h1 >L _W0 ·M/(1−M), ratio of the second hood hood The cross-sectional area ratio σ _h ≈1.4 to 1.5, the total length of the second entrance hood L _h2 ≧L _h1 , and the length of the radiating portion L _h3 ≈0.35 to 0.4 L _W0 ,
A micro-pressure wave reduction structure characterized by In the micro-pressure wave reducing structure according to any one of claims 1 to 6,
An opening/closing part for opening/closing the radiation part is provided,
The opening/closing section closes the radial section when the moving body enters the entrance hood, and opens the radial section when the moving body enters the opposite tunnel portal;
A micro-pressure wave reduction structure characterized by In the micro-pressure wave reducing structure according to any one of claims 1 to 6,
a variable length section for varying the length of the radiating section;
The length variable section varies the length of the radiation section to a predetermined length when the moving body enters the entrance hood, and changes the length of the radiation section when the moving body enters the tunnel entrance on the opposite side. varying the length of the section to zero;
A micro-pressure wave reduction structure characterized by

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