A buffer structure for mitigating micro-pressure waves at the entrance of high-speed railway tunnels

Abstract

The present invention discloses a buffer structure for alleviating micro-pressure waves at the entrance of a high-speed railway tunnel. The structure comprises a buffer structure body, the outer end face of which is a beveled surface, and an arched plate disposed between the buffer structure body and the tunnel clearance. The axis of the arched plate is arranged to coincide with the axis of the tunnel, and the outer end face of the arched plate is arranged coplanar with the outer end face of the buffer structure body. The arched plate and the buffer structure body are aligned with the outer end face of the tunnel to form a decompression zone with an open outer end and a closed inner end. The arched plate is provided with a plurality of through holes that communicate with the decompression chamber. The present invention can reduce the amount of compression waves generated when airflow enters the tunnel; it can dissipate the energy of the compression waves, and more efficiently alleviate micro-pressure waves at the tunnel exit.

Description

Technical Field

[0001] The present invention relates to the field of tunnel aerodynamics, and in particular to a buffer structure for alleviating micro-pressure waves at a high-speed railway tunnel portal. Background Art

[0002] When a high-speed train enters a tunnel, the air ahead is confined by the tunnel walls, generating compression waves. These waves propagate outward at the tunnel exit in the form of micro-pressure waves, causing a series of aerodynamic issues, including sonic booms at the tunnel entrance and structural vibrations. As train speeds continue to increase, the aerodynamic effects of vehicle-tunnel coupling will become more pronounced, and the impact of these micro-pressure waves at the tunnel exit on the surrounding environment will become even more severe.

[0003] At present, the main measure to mitigate micropressure waves is to add buffer structures at tunnel entrances. While the buffer structures currently used have a certain effect on mitigating micropressure waves, when the train speed reaches 400 km / h, the amplitude of the micropressure waves at the tunnel entrance under the existing buffer structures exceeds the standard value of micropressure waves at the entrances of high-speed railway tunnels in my country (TB 10761-2013). Furthermore, due to factors such as the terrain and the tunnel entrance environment, the mitigation effect of the existing buffer structures is difficult to further improve. Summary of the Invention

[0004] The purpose of the present invention is to address the deficiencies of the prior art and provide a buffer structure that can effectively improve the buffering effect of micro-air pressure waves at the entrance of a high-speed railway tunnel.

[0005] The buffer structure provided by the present invention is used to alleviate micro-air pressure waves at the entrance of a high-speed railway tunnel, including a buffer structure body arranged at the tunnel entrance, the outer end face of the buffer structure body being a beveled surface, an arched plate being sleeved between the buffer structure body and the tunnel clearance, the axis of the arched plate being arranged to coincide with the axis of the tunnel, the arched plate and the buffer structure body being connected to the outer end face of the tunnel to form a decompression zone with an open outer end and a closed inner end, and a plurality of through holes connected to the decompression chamber are opened on the arched plate.

[0006] The cross-sectional area of the buffer structure body is twice the cross-sectional area of the tunnel.

[0007] The through hole is square or circular.

[0008] The through holes are arranged in multiple rows along the axial direction of the arched plate, and the through holes in the same row are arranged at equal intervals along the axial direction of the arched plate.

[0009] The through holes are arranged in four rows along the axial direction of the arched plate, two rows are symmetrically arranged on the left and right sides of the upper part of the arched plate, and two rows are symmetrically arranged on the left and right sides of the lower part of the arched plate.

[0010] The slope of the beveled surface is 1:1.5.

[0011] First, the present invention reduces the restriction of the buffer structure wall on the air flow through an inclined section, enabling the air in front of the high-speed train to flow upward and be released above the tunnel, thereby reducing the amount of compression waves generated when it enters the tunnel. Then, through the through-holes, the pressure waves generated when the high-speed train enters the present invention are transmitted to the pressure relief area. The pressure waves in the pressure relief area are reflected and consumed multiple times under the blocking effect between the inner surface of the buffer structure body and the outer surface of the arched plate, thereby greatly reducing the initial compression wave gradient and dissipating the compression wave energy to a greater extent, so as to more efficiently relieve the micro-pressure wave at the tunnel exit. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is an axonometric structure schematic diagram of the present invention.

[0013] Figure 2 is Figure 1 The enlarged cross-sectional structure schematic diagram at A-A in

[0014] Figure 3 is Figure 1 The enlarged cross-sectional structure schematic diagram at B-B in

[0015] The marks shown in the figure and the corresponding component names are:

[0016] 1. Buffer structure body; 11. Inclined section;

[0017] 2. Arched plate; 21. Through-hole;

[0018] 3. Pressure relief area;

[0019] a. Outer end face of the tunnel; b. Inner contour line of the tunnel. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] It can be seen from Figures 1 to 3 that the buffer structure for relieving the micro-pressure wave at the entrance of the high-speed railway tunnel of the present invention includes a buffer structure body 1 and an arched plate 2 arranged at the tunnel entrance. The arched plate 2 is laid on the road surface along the tunnel running direction. The axis of the arched plate 2 coincides with the tunnel axis, and the inner contour line of the arched plate 2 is arranged not less than the inner contour line b of the tunnel. The buffer structure body 1 is sleeved outside the arched plate 2 with a gap. The inner end face of the arched plate 2 is in close butt joint with the outer end face a of the tunnel, and the inner end face of the buffer structure body 1 is in close butt joint with the outer end face a of the tunnel. The buffer structure body 1, the arched plate 2 and the outer end face a of the tunnel enclose a pressure relief area 3 with an open outer end and a closed inner end. The outer end faces of the buffer structure body 1 and the arched plate 2 are inclined sections 11 arranged on the same plane. A plurality of square through-holes 21 communicating with the pressure relief cavity 3 are opened on the arched plate 2. The through-holes 21 are arranged in multiple rows along the axial direction of the arched plate 2, and the through-holes 21 in the same row are arranged at equal intervals along the axial direction of the arched plate 2.

[0021] It can be seen fromFigures 1 to 3 It can be seen that in the present invention, four rows of square through holes 21 are provided on the arched plate 2, and each row of through holes 21 is arranged along the axial direction of the arched plate 2. Among them, two rows of through holes 21 are symmetrically arranged on the left and right sides of the upper part of the arched plate 2, with 16 in each row; two rows of through holes 21 are symmetrically arranged on the left and right sides of the lower part of the arched plate 2, with 17 in each row; the distance between the through holes 21 in the same row is 5 m, and the side length of the through hole 21 is 4.17 m.

[0022] In the present invention, the cross-sectional area of the buffer structure body 1 is 200 m 2 , which is twice the cross-sectional area of the tunnel, and the length of the bottommost end is 100 m.

[0023] In the present invention, the through hole 21 can also be circular; the slope of the inclined plane 11 is 1:1.5.

[0024] The construction method of the buffer structure for alleviating the micro-pressure wave at the entrance of a high-speed railway tunnel in the present invention includes the following steps:

[0025] S1. According to the inner contour line b of the tunnel, formulate the design parameters of the inner contour line of the arched plate 2, so that the inner contour line of the arched plate 2 is arranged not less than the inner contour line b of the tunnel; according to the method of computational fluid dynamics, formulate the design parameters of the thickness, length of the arched plate 2, and the number of rows and the number of each row of through holes 21 provided on the arched plate 2;

[0026] S2. Starting from the outer end face a of the tunnel, along the tunnel axis, according to the design parameters in step S1, formwork and pour the arched plate 2 with through holes 21 reserved outside the tunnel entrance, and ensure that the inner end face of the arched plate 2 is hermetically connected to the outer end face a of the tunnel;

[0027] S3. According to the outer contour line of the arched plate 2 and the cross-sectional area of the tunnel, formulate the design parameters of the buffer structure body 1, ensure that the inner surface of the buffer structure body 1 is arranged with a gap from the outer surface of the arched plate 2, and the cross-sectional area of the buffer structure body 1 is twice the cross-sectional area of the tunnel;

[0028] S4. Starting from the outer end face a of the tunnel, along the tunnel axis, according to the design parameters in step S3, formwork and pour the buffer structure body 1 around the arched plate 2, and ensure that the inner end face of the buffer structure body 1 is hermetically connected to the outer end face a of the tunnel. The arched plate 2, the buffer structure body 1 and the outer end face a of the tunnel enclose a pressure reduction area 3 with an outer end opening and an inner end closed.

[0029] The micro-pressure wave generated when a high-speed train passes through the tunnel provided with the present invention at a speed of 400 km / h was studied. Through numerical simulation verification, the data shown in Table 1 can be obtained:

[0030] Table 1

[0031]

[0032]

[0033] As can be seen from Table 1, the present invention can reduce the micro-pressure wave at 20 m from the tunnel exit by 78.7%, and the reduction effect of the micro-pressure wave at 50 m from the tunnel exit reaches 73.8%. The amplitudes of the micro-pressure waves at the tunnel entrance under the present invention all meet the micro-pressure wave standard for railway tunnels: the micro-pressure wave at 20 m from the tunnel exit should be less than 50 Pa, and the micro-pressure wave at 50 m from the tunnel exit should be less than 20 Pa.

[0034] The present invention is applicable not only to high-speed railway tunnels but also to maglev railway tunnel structures.

[0035] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only the preferred embodiments of the present invention and are not used to limit the protection scope of the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A buffer structure for mitigating micro-pressure waves at the entrance of a high-speed railway tunnel, comprising a buffer structure body (1) arranged at the tunnel entrance, characterized in that: The outer end face of the buffer structure body is a beveled surface (11), and an arched plate (2) is sleeved between the buffer structure body and the tunnel clearance. The axis of the arched plate is arranged to coincide with the axis of the tunnel, and the outer end face of the arched plate is arranged coplanar with the outer end face of the buffer structure body. The arched plate and the buffer structure body are connected to the outer end face of the tunnel to form a decompression zone (3) with an open outer end and a closed inner end. A plurality of through holes (21) connected to the decompression cavity are opened on the arched plate, so that the pressure wave generated after the high-speed train enters the buffer structure is propagated into the decompression zone. The pressure wave in the decompression zone is subjected to multiple reflection and consumption phenomena under the back-and-forth blocking action of the inner surface of the buffer structure body and the outer surface of the arched plate, thereby reducing the initial compression wave gradient, dissipating the compression wave energy, and alleviating the micro-air pressure wave at the tunnel exit. The cross-sectional area of the buffer structure body is twice the cross-sectional area of the tunnel. The through holes are arranged in multiple rows along the axial direction of the arched plate, and the through holes in the same row are arranged at equal intervals along the axial direction of the arched plate. The slope of the beveled surface is 1:1.

5.

2. The buffer structure for mitigating micro-pressure waves at the entrance of high-speed railway tunnels according to claim 1, wherein: The through hole is square or circular.

3. The buffer structure for mitigating micro-pressure waves at the entrance of high-speed railway tunnels according to claim 1, wherein: The through holes are arranged in four rows along the axial direction of the arched plate, two rows are symmetrically arranged on the left and right sides of the upper part of the arched plate, and two rows are symmetrically arranged on the left and right sides of the lower part of the arched plate.

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