Combined buffer structure for high-speed railway tunnel portal

Abstract

The utility model relates to a combined buffer structure of a high-speed railway tunnel portal, which comprises an opening section connected with a tunnel portal lining structure of a tunnel entrance and exit, the opening section comprises at least one opening section lining, a plurality of surrounding wells are arranged at the top of the opening section lining at intervals, the surrounding wells protrude out of the upper end face of the opening section lining, and the opening section lining is connected with the opening section lining structure of the tunnel entrance and exit. A cavity in the open section lining is communicated with the outside through the trunk; and the beveled section lining is spliced with the opening section lining at the end of the opening section, the end opening of the beveled section lining is inclined, and the inclined direction of the beveled section lining faces the tunnel portal. A plurality of opening section linings can be arranged according to requirements, then the parameters such as the opening position and length of the buffer structure are flexibly adjusted, and meanwhile the design of the trunk can effectively prevent falling rocks of a side slope from falling into a line.

Description

Technical Field

[0001] This utility model relates to the field of tunnel portal structures, specifically a combined buffer structure for the portal of a high-speed railway tunnel. Background Technology

[0002] When a high-speed train passes through a tunnel at high speed, the air in the annular space between the train and the inner surface of the tunnel lining is violently compressed due to the train's front entering the tunnel. This creates a compression wave in front of the train, which propagates within the tunnel at the speed of sound. When the compression wave reaches the tunnel entrance, some of the energy is reflected back into the tunnel as an expansion wave, while the rest radiates into the external environment, forming micro-pressure waves. These micro-pressure waves at the tunnel entrance contain a large number of low-frequency infrasound waves with vibration frequencies between 0 and 20 Hz. These waves can easily trigger resonance in the structures of surrounding buildings (such as doors and windows), as well as in human cavities and vital organs, jeopardizing structural safety and causing negative physiological and psychological impacts on nearby residents. Furthermore, when the peak value of the micro-pressure wave is large, the high-frequency components can induce a sonic boom, creating noise pollution at the tunnel entrance.

[0003] To address the issue of micro-pressure wave environment at tunnel entrances, the main mitigation methods include: 1) Modifying the tunnel structure: such as appropriately increasing the tunnel's clearance area or constructing auxiliary tunnels within the tunnel, thereby mitigating micro-pressure waves at the tunnel entrance; 2) Changing train design parameters: such as increasing the streamlined length of the train's nose or altering the train's cross-sectional area, thereby reducing the initial compression wave gradient; 3) Modifying the type of buffer structure at the tunnel entrance: such as increasing the opening ratio of the buffer structure or extending its length, thereby reducing the initial compression wave gradient and enhancing the mitigation effect of micro-pressure waves. Since the design parameters of tunnels and trains are difficult to change during construction, both domestically and internationally, the main approach is to add buffer structures at the tunnel entrance to mitigate micro-pressure waves.

[0004] Regarding the mitigation mechanism of buffer structures, existing research indicates that the micro-pressure wave at the tunnel exit is positively correlated with the pressure gradient inside the tunnel and negatively correlated with the solid angle of the exit space. For the buffer structure at the tunnel inlet, the main mechanism is to reduce the peak value of the pressure gradient by extending the time it takes for the initial compression wave to reach its peak value, thereby reducing the peak value of the micro-pressure wave. For the buffer structure at the tunnel exit, the main mechanism is to increase the solid angle of the exit space, thereby reducing the peak value of the micro-pressure wave.

[0005] Based on the ratio of the cross-sectional area to the net area of ​​the buffer structure, it can be divided into equal cross-section type (=1:1) and enlarged cross-section type (>1:1). Among them, due to the structural size limitations of the enlarged cross-section type, it has a larger land requirement for the opening site, and it is often impossible to build an enlarged cross-section buffer structure in terrain with small opening space.

[0006] The existing buffer structures have fixed design parameters such as the location and length of openings, making it difficult to design according to mitigation needs, resulting in low economic efficiency. Furthermore, the design of the openings does not consider the risk of falling rocks from the surrounding rock, leading to poor safety. Utility Model Content

[0007] The technical problem to be solved by this utility model is to provide a combined buffer structure that can be equipped with several open sections for lining as needed, thereby flexibly adjusting the opening position and length of the buffer structure, and effectively preventing rocks from falling from the slope into the line, thus achieving the purpose of protection.

[0008] To solve the above problems, the technical solution adopted by this utility model is as follows:

[0009] A combined buffer structure for the entrance of a high-speed railway tunnel, comprising:

[0010] An opening section is connected to the portal lining structure of the tunnel entrance and exit. The opening section includes at least one opening section lining. Several cofferdams are spaced apart on the top of the opening section lining. The cofferdams protrude from the upper end face of the opening section lining. The cavity inside the opening section lining is connected to the outside through the cofferdams.

[0011] The oblique section lining is spliced ​​with the opening section lining at the end of the opening section. The port of the oblique section lining is inclined, and its inclination direction is towards the tunnel entrance.

[0012] In a preferred embodiment, the cross-sectional area of ​​the buffer structure is consistent with the tunnel clearance.

[0013] In a preferred embodiment, the opening segment includes at least two opening segment linings, with adjacent opening segment linings joined together.

[0014] In a preferred embodiment, the cross-section of the well is circular or rectangular.

[0015] In a preferred embodiment, a wellhead groove is provided on the inner side of the upper end of the well, and the wellhead groove is used to install a protective net.

[0016] In a preferred embodiment, the inclination rate at the port of the oblique section lining is consistent with the slope of the terrain slope protection at the tunnel entrance and exit.

[0017] In a preferred embodiment, the port edge of the oblique section lining is provided with a protruding brim structure, the distance of which the brim structure protrudes from the port edge of the oblique section lining increases from bottom to top.

[0018] In a preferred embodiment, the length of the oblique section lining along the tunnel direction is 15 meters, and the length of the open section lining along the tunnel direction is 10 meters.

[0019] The top of the opening section lining is provided with two wells, the wells are rectangular in cross-section, the thickness is 0.5 meters, and the inner dimensions of the wells are: 3 meters long and 3.2 meters wide.

[0020] The center-to-center distance between two adjacent wells is 5 meters, and the straight-line distance between the center of the well and the edge of the lining of the opening section is 2.5 meters.

[0021] The inclination ratio at the port of the oblique section lining is 1:1.25.

[0022] In a preferred embodiment, both the open section lining and the oblique section lining are constructed using reinforced concrete.

[0023] In a preferred embodiment, the well is constructed using reinforced concrete.

[0024] The beneficial effects of adopting the above technical solution are as follows:

[0025] This application provides a combined equal cross-section buffer structure, which divides the buffer structure into oblique section lining and open section lining. The number of open section linings can be changed according to the requirements of the micro-pressure wave mitigation rate, thereby changing the design of the structure length and flexibly adjusting the parameters such as the opening position and length of the buffer structure.

[0026] This application includes a cofferdam in the lining of the open section, which connects the cavity inside the lining of the open section to the outside world, and also serves as a protective measure to prevent rocks from falling from the slope into the railway line. Attached Figure Description

[0027] Figure 1 This is a structural schematic diagram of an embodiment.

[0028] Figure 2 This is a schematic diagram of the structure of the lining of the opening section in an embodiment.

[0029] Figure 3 This is a schematic diagram of the oblique section lining structure in an embodiment.

[0030] Figure 4 yes Figure 3 The main view.

[0031] Figure 5 This is a schematic diagram of another embodiment.

[0032] Among them: 1. External surface structure; 2. Topographic slope protection; 3. Opening section lining; 3-1. Cofferdam; 3-2. Wellhead trench; 4. Inclined section lining; 5. Cap structure; 6. Inclined shear rate. Detailed Implementation

[0033] To make the objectives, technical solutions and advantages of this utility model clearer, the utility model will be clearly and completely described below in conjunction with specific embodiments.

[0034] like Figures 1 to 4 The diagram shows a combined buffer structure at the entrance of a high-speed railway tunnel, installed on the surface structure 1 outside the tunnel to reduce the peak value of micro-pressure waves. It includes:

[0035] An opening section is connected to the portal lining structure of the tunnel entrance and exit (the two ends of the tunnel). The opening section includes at least one opening section lining 3. Several cofferdams 3-1 are spaced apart on the top of the opening section lining 3. The cofferdams 3-1 protrude from the upper surface of the opening section lining 3. The protrusion height of the cofferdams 3-1 ensures that falling rocks are difficult to enter the track. The cavity inside the opening section lining 3 is connected to the outside through the cofferdams 3-1.

[0036] The oblique section lining 4 is spliced ​​with the opening section lining 3 at the end of the opening section. The port of the oblique section lining 4 is inclined, and its inclination direction is towards the tunnel entrance.

[0037] In this embodiment, both the open section lining 3 and the oblique section lining 4 are made of reinforced concrete. The cofferdam 3-1 is also made of reinforced concrete. The splicing process for the gaps between the linings can be achieved by adhesive bonding (using structural adhesive or other types of adhesive to bond two concrete components together) or by connecting the joints between adjacent components through concrete pouring.

[0038] In this embodiment, the cross-sectional area of ​​the buffer structure is consistent with the tunnel clearance (tunnel clearance refers to the space enclosed by the tunnel's inner outline, including the cross-sectional area required for highway tunnel construction clearance, ventilation, and other functions).

[0039] The opening segment includes at least two opening segment liners 3, see [link to relevant documentation]. Figure 4 According to the requirements, it can be set as 4 sets of open section lining 3, and two adjacent open section lining 3 are spliced ​​together.

[0040] In this embodiment, the well 3-1 has a rectangular cross-section, preferably a circular shape. A wellhead groove 3-2 is provided on the inner side of the upper end of the well 3-1, and the wellhead groove 3-2 is used to apply screw components to install the protective net.

[0041] See Figure 1 and Figure 4The inclination rate 6 at the port of the oblique section lining 4 is consistent with the slope of the terrain slope 2 at the tunnel entrance and exit.

[0042] See Figure 3 and Figure 4 The oblique section lining 4 has a protruding brim structure 5 at its port edge, and the distance of the brim structure 5 protruding from the port edge of the oblique section lining 4 increases from bottom to top.

[0043] In a preferred embodiment, the length of the oblique-cut lining 4 along the tunnel direction is 15 meters, and the length of the open-section lining 3 along the tunnel direction is 10 meters. Two retaining wells 3-1 are provided at the top of the open-section lining 3. Each retaining well 3-1 has a rectangular cross-section and a thickness of 0.5 meters. The inner dimensions of each retaining well 3-1 are: length 3 meters and width 3.2 meters. The center-to-center distance between two adjacent retaining wells 3-1 is 5 meters, and the straight-line distance between the center of each retaining well 3-1 and the edge of the open-section lining 3 is 2.5 meters. The inclination ratio 6 at the end of the oblique-cut lining 4 is 1:1.25. Under this scheme, when the number of additional opening sections with lining is 1, 2, 3, and 4, the lengths of the buffer structure are 25, 35, 45, and 55 m, respectively. According to the results of three-dimensional CFD numerical simulation, the peak values ​​of micro-pressure waves 20 m outside the opening of the buffer structure are 64.9, 41.8, 28.7, 26.5, and 21.2 Pa, respectively. The peak value of micro-pressure waves at the opening without the buffer structure of this embodiment is 110.6 Pa. The micro-pressure wave mitigation rates can be obtained as 62.2%, 74.1%, 76.0%, and 80.8%, respectively.

[0044] When the high-speed train enters the entrance, the buffer structure of this embodiment can effectively reduce the initial compression wave pressure gradient, thereby reducing the peak value of the micro-pressure wave; for the tunnel exit buffer structure, the inclined port of the oblique section lining 4 increases the solid angle of the exit space, thereby reducing the peak value of the micro-pressure wave. The joint mitigation effect of the inlet and outlet buffer structures achieves the purpose of reducing the peak value of the micro-pressure wave.

[0045] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A combined buffer structure for the entrance of a high-speed railway tunnel, characterized in that, It includes: An opening section is connected to the portal lining structure of the tunnel entrance and exit. The opening section includes at least two opening section linings (3), and two adjacent opening section linings (3) are spliced ​​together. Several cofferdams (3-1) are provided at intervals on the top of the opening section lining (3). The cofferdams (3-1) protrude from the upper end face of the opening section lining (3). The cavity inside the opening section lining (3) is connected to the outside through the cofferdams (3-1). The oblique section lining (4) is spliced ​​with the opening section lining (3) at the end of the opening section. The port of the oblique section lining (4) is inclined and its inclination direction is towards the tunnel entrance. Both the open section lining (3) and the oblique section lining (4) are made of reinforced concrete. The splicing process of the gaps between the linings can be by using an adhesive or by connecting the joints between adjacent components by pouring concrete.

2. The combined buffer structure at the entrance of a high-speed railway tunnel according to claim 1, characterized in that, The cross-sectional area of ​​the buffer structure is consistent with the tunnel clearance.

3. The combined buffer structure at the entrance of a high-speed railway tunnel according to claim 1, characterized in that, The cross-section of the well (3-1) is circular or rectangular.

4. The combined buffer structure at the entrance of a high-speed railway tunnel according to claim 1, characterized in that, A wellhead groove (3-2) is provided on the inner side of the upper end of the well (3-1), and the wellhead groove (3-2) is used to install a protective net.

5. A combined buffer structure for high-speed railway tunnel entrances according to claim 1, characterized in that, The inclination (6) at the port of the oblique section lining (4) is consistent with the slope of the topographic slope protection (2) at the tunnel entrance and exit.

6. A combined buffer structure for high-speed railway tunnel entrances according to claim 1, characterized in that, The port edge of the oblique section lining (4) is provided with a protruding brim structure (5), and the distance of the brim structure (5) protruding from the port edge of the oblique section lining (4) increases from bottom to top.

7. A combined buffer structure for high-speed railway tunnel entrances according to claim 1, characterized in that, The oblique section lining (4) is 15 meters long along the tunnel direction, and the open section lining (3) is 10 meters long along the tunnel direction. The top of the opening section lining (3) is provided with two wells (3-1). The cross-section of the well (3-1) is rectangular and its thickness is 0.5 meters. The inner diameter of the well (3-1) is 3 meters long and 3.2 meters wide. The center-to-center distance between two adjacent wells (3-1) is 5 meters, and the straight-line distance between the center of the well (3-1) and the edge of the opening section lining (3) is 2.5 meters; The inclination (6) at the port of the oblique section lining (4) is 1:1.

25.

8. A combined buffer structure for high-speed railway tunnel entrances according to claim 1, characterized in that, The well (3-1) is made of reinforced concrete.

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