Vibration response model of subway tunnels with back walls

Abstract

This utility model discloses a vibration response model for a subway tunnel with a cavity behind the wall, belonging to the field of tunnel engineering technology. Multiple first airbags are installed in the assembly space between the lining and the outer cylinder. An inflation device is used to inflate all the first airbags, applying pressure to the lining through these airbags to simulate the pressure exerted by the soil on the lining. Then, one or more of the first airbags are depressurized, creating an unpressurized cavity in the outer wall of the lining at that airbag location, simulating a cavity behind the wall of the lining. Finally, a train moves along the track to simulate subway operation, and multiple vibration sensors on the lining monitor the vibration response. By changing the position and number of the depressurized first airbags, the influence of cavities with different positions, sizes, and numbers behind the wall on the lining during train operation is verified.

Description

Technical Field

[0001] This utility model relates to the field of tunnel engineering technology, and in particular to a vibration response model for a subway tunnel with a cavity behind the wall. Background Technology

[0002] Voids behind the lining walls of subway tunnels are concealed and pose significant potential hazards. These voids unload the load from the surrounding rock, causing a redistribution of pressure and increasing nearby ground pressure. This leads to stress concentration under eccentric loads on the tunnel structure, resulting in insufficient structural bearing capacity. The voids become focal points for lining damage and can even lead to collapse. Under repeated train loads, voids behind the lining walls can cause cracking, misalignment, and even concrete spalling, seriously threatening the structural health of the tunnel and the safety of train operations. However, existing subway tunnel models are insufficient to simulate the situation of voids behind the lining walls and cannot verify their impact on subway tunnels. Utility Model Content

[0003] This utility model aims to solve the technical problems existing in the above-mentioned related technologies, and proposes a vibration response model for a subway tunnel with back wall cavities to verify the influence of back wall cavities of different positions, sizes and numbers on the lining during train operation.

[0004] The vibration response model of a subway tunnel with a cavity behind the wall according to an embodiment of the present invention includes: The outer cylinder is arranged horizontally, and the outer cylinder is provided with an axially penetrating mounting hole; A lining is provided at the mounting hole, the lining having an axially penetrating tunnel, and an assembly space is formed between the outer wall of the lining and the inner wall of the mounting hole; An inflatable assembly includes a plurality of first airbags arranged sequentially along the circumference of the liner in the assembly space. Multiple vibration sensors are distributed at circumferential intervals along the lining; The track is laid at the bottom of the tunnel; The train moves along the track.

[0005] The vibration response model of a subway tunnel with a cavity behind the wall according to an embodiment of the present invention has at least the following beneficial effects: multiple first airbags are set in the assembly space between the lining and the outer cylinder, and all the first airbags are inflated using an inflation device. Pressure is applied to the lining through the multiple first airbags to simulate the pressure of the soil on the lining. Then, one or more of the first airbags are depressurized, so that the outer wall of the lining forms an unpressurized cavity at the first airbag, simulating the cavity behind the wall of the lining. Finally, the train moves along the track to simulate the subway operation, and the vibration response of the lining is monitored by multiple vibration sensors on the lining. By changing the position and number of the depressurized first airbags, the influence of cavities behind the wall with different positions, sizes and numbers on the lining during train operation is verified.

[0006] According to some embodiments of the present invention, the inflation assembly further includes: Multiple second airbags are arranged sequentially along the circumference of the lining in the assembly space; Multiple third airbags are arranged sequentially along the circumference of the lining in the assembly space; The first airbag, the second airbag, and the third airbag are staggered along the axial direction of the lining, and the volumes of the first airbag, the second airbag, and the third airbag are different from each other.

[0007] According to some embodiments of the present invention, the volume of the first airbag, the volume of the second airbag, and the volume of the third airbag increase sequentially.

[0008] According to some embodiments of the present invention, the first airbag, the second airbag, and the third airbag are all arc-shaped, the arc length of the second airbag is equal to the arc length of the third airbag, and the arc length of the second airbag is greater than the arc length of the first airbag.

[0009] According to some embodiments of the present invention, the thickness of the first airbag, the second airbag, and the third airbag gradually increases.

[0010] According to some embodiments of the present invention, the first airbag, the second airbag, and the third airbag are spaced apart from each other.

[0011] According to some embodiments of the present invention, the sidewall of the lining is divided into an arch top, an arch shoulder, an arch waist, an arch foot, and an arch bottom from top to bottom. The lining also includes a floating plate, which is movably disposed at the arch bottom. A plurality of vibration sensors are disposed one-to-one at the arch top, the arch shoulder, the arch waist, the arch foot, and the floating plate.

[0012] According to some embodiments of the present invention, the vibration response model further includes: Multiple pressure sensors are provided, with one pressure sensor located between each of the first airbags and the outer wall of the lining.

[0013] According to some embodiments of the present invention, at least one of the vibration sensors is disposed on the train.

[0014] According to some embodiments of the present invention, the vibration response model further includes: Multiple strain sensors are distributed at circumferential intervals along the lining. Attached Figure Description

[0015] Figure 1 This is a structural schematic diagram of a vibration response model of a subway tunnel with a cavity behind the wall, according to an embodiment of the present invention. Figure 2 This is a cross-sectional view along the axial direction of a vibration response model according to an embodiment of the present invention; Figure 3 This is a radial cross-sectional view of the vibration response model according to an embodiment of the present invention.

[0016] Reference numerals: 10 for the partition airbag, 100 for the outer cylinder, 110 for the mounting hole, 200 for the lining, 201 for the assembly space, 210 for the tunnel, 211 for the arch crown, 212 for the arch shoulder, 213 for the arch waist, 214 for the arch foot, 215 for the arch bottom, 216 for the floating plate, 300 for the first airbag, 400 for the second airbag, 500 for the third airbag, 600 for the track, and 700 for the train. Detailed Implementation

[0017] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0018] In the description of this utility model, it should be understood that the terms front, back, up, down, axial, circumferential, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0019] In the description of this utility model, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly specifying the number of indicated technical features or their sequential relationship.

[0020] In the description of this utility model, it should be noted that terms such as "setting," "installing," and "connecting" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0021] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of this utility model, not all embodiments.

[0022] As a crucial component of subway systems, the demand for high-quality operation of subway tunnels is rapidly increasing. However, statistics show that tunnels commonly suffer from defects such as joint deformation, segment cracking, water leakage, and voids behind the tunnel walls. Among these, voids behind the walls are particularly insidious and hazardous, posing a significant technical challenge to the long-term operational safety of tunnels. These voids primarily form during tunnel construction and can expand during operation, potentially inducing cracking or even spalling of the lining structure, severely impacting the load-bearing capacity of the tunnel structure. Traffic accidents caused by lining instability due to voids behind the walls occur frequently, resulting in substantial losses. Currently, the problem of voids behind tunnel walls is prominent. Researching the impact of voids on tunnel structures, especially their dynamic response under train loads, is crucial for developing a method for identifying voids behind the walls based on vibration response monitoring. This is also an urgent need to ensure the healthy development of tunnels.

[0023] Therefore, this utility model proposes a vibration response model for a subway tunnel with back wall cavities to verify the influence of back wall cavities of different positions, sizes and numbers on the lining during train operation.

[0024] Reference Figures 1 to 3 As shown, this utility model provides a vibration response model for a subway tunnel with a cavity behind the wall.

[0025] The vibration response model includes the outer cylinder 100, the lining 200, the air-filled assembly, the track 600, and the train 700.

[0026] The outer cylinder 100 is cylindrical, and an installation hole 110 is provided inside the outer cylinder 100. The installation hole 110 extends through the outer cylinder 100 along the axial direction. The lining 200 is disposed in the installation hole 110 of the outer cylinder 100 and extends along the axial direction of the outer cylinder 100. A space is left between the outer wall of the lining 200 and the inner wall of the installation hole 110 to form an assembly space 201.

[0027] The inflation assembly includes an inflation device, multiple first airbags 300, multiple second airbags 400 and multiple third airbags 500. The inflation device is connected to all the first airbags 300, all the second airbags 400 and all the third airbags 500. The inflation device can control the air pressure of any one of the airbags.

[0028] Each first airbag 300, each second airbag 400, and each third airbag 500 is designed in an arc shape, with the arc length of the first airbag 300 being less than the arc length of the second airbag 400, and the arc length of the second airbag 400 being equal to the arc length of the third airbag 500.

[0029] All first airbags 300, all second airbags 400, and all third airbags 500 are arranged in the assembly space 201. All first airbags 300 are arranged sequentially along the circumference of the lining 200, all second airbags 400 are arranged sequentially along the circumference of the lining 200, and all third airbags 500 are arranged sequentially along the circumference of the lining 200. The first airbags 300 and second airbags 400 are spaced apart front to back, and the second airbags 400 and third airbags 500 are spaced apart front to back. The inflation device inflates all first airbags 300, all second airbags 400, and all third airbags 500, so that the first airbags 300 abut against the inner wall of the mounting hole 110 and the outer wall of the lining 200, the second airbags 400 abut against the inner wall of the mounting hole 110 and the outer wall of the lining 200, and the third airbags 500 abut against the inner wall of the mounting hole 110 and the outer wall of the lining 200.

[0030] In this embodiment, a second groove and a third groove are provided on the inner sidewall of the mounting hole 110. Both the second groove and the third groove are recessed outwards and encircle the mounting hole 110 in a circle. The second groove and the third groove are distributed at intervals. The distance of the second groove's outward recess is less than the distance of the third groove's outward recess. All second airbags 400 are disposed in the second groove, and all third airbags 500 are disposed in the third groove. Therefore, the thickness of the first airbag 300 along the radial direction of the mounting hole 110 is less than the thickness of the second airbag 400 along the radial direction of the mounting hole 110, and the thickness of the second airbag 400 along the radial direction of the mounting hole 110 is less than the thickness of the third airbag 500 along the radial direction of the mounting hole 110.

[0031] In this embodiment, after the inflation device inflates the first airbag 300, the second airbag 400 and the third airbag 500, the volume of the first airbag 300 is smaller than the volume of the second airbag 400, and the volume of the second airbag 400 is smaller than the volume of the third airbag 500.

[0032] The remaining space of the assembly space 201 is provided with a partition airbag 10. The partition airbag 10 is fixed on the inner wall of the mounting hole 110 to ensure that the position of the partition airbag 10 does not change and the air pressure of the partition airbag 10 remains unchanged, so as to simulate the situation where the lining 200 is squeezed by the soil, and keep the air pressure of the first airbag 300, the second airbag 400, the third airbag 500 and the partition airbag 10 consistent.

[0033] By using the separator airbag 10 to separate the first airbag 300, the second airbag 400 and the third airbag 500 from each other, the position of the remaining airbags is avoided due to the depressurization of the first airbag 300, the second airbag 400 or the third airbag 500. This can prevent the first airbag 300, the second airbag 400 or the third airbag 500 from affecting each other and improve the accuracy of the test.

[0034] Of course, a partition airbag 10 can be set between every two adjacent first airbags 300, between every two adjacent second airbags 400, and between every two adjacent third airbags 500 to ensure that the pressure on the periphery of the lining 200 is evenly distributed.

[0035] The sidewalls of the lining 200 are divided from top to bottom into an arch 211, an arch shoulder 212, an arch waist 213, an arch foot 214, and an arch bottom 215. Multiple first airbags 300 are arranged one-to-one in the arch 211, arch shoulder 212, arch waist 213, arch foot 214, and arch bottom 215. By depressurizing any one of the first airbags 300, the voids behind the arch 211, arch shoulder 212, arch waist 213, arch foot 214, and arch bottom 215 are simulated. Similarly, multiple second airbags 400 are arranged one-to-one in the arch 211, arch shoulder 212, arch waist 213, arch foot 214, and arch bottom 215, and multiple third airbags 500 are arranged one-to-one in the arch 211, arch shoulder 212, arch waist 213, arch foot 214, and arch bottom 215.

[0036] The lining 200 has a tunnel 210 inside, which extends along the axial direction of the lining 200. A movable floating plate 216 is provided at the bottom of the tunnel 210, and a track 600 is installed on the top of the floating plate 216. The track 600 is arranged along the axial direction of the tunnel 210, and the train 700 runs on the track 600.

[0037] To accurately measure the vibration impact caused by the void behind the lining 200, multiple vibration sensors are installed on the outer wall of the lining 200, with each sensor corresponding to one of the arch top 211, arch shoulder 212, arch waist 213, arch foot 214, and floating plate 216. This allows for the measurement of vibration at various locations of the lining 200, thus verifying the amount of vibration at each location of the lining 200 during train 700 operation.

[0038] In order to accurately adjust the pressure of the first airbag 300, the second airbag 400, the third airbag 500 and the partition airbag 10 on the outer wall of the lining 200, multiple pressure sensors are set on the outer wall of the lining 200 at intervals, with one pressure sensor corresponding to each first airbag 300, each second airbag 400, each third airbag 500 and each partition airbag 10.

[0039] To measure the impact of the back cavity at different locations of the lining 200 on the train 700, a vibration sensor was installed on the train 700.

[0040] To verify the displacement of lining 200 caused by the void behind the wall, multiple strain sensors were installed on the inner wall of lining 200 at intervals.

[0041] Multiple first airbags 300, multiple second airbags 400, and multiple third airbags 500 are provided in the assembly space 201 between the lining 200 and the outer cylinder 100. An inflation device is used to inflate all the first airbags 300, all the second airbags 400, and all the third airbags 500, applying pressure to the lining 200 through all the first airbags 300, all the second airbags 400, and all the third airbags 500 to simulate the pressure of soil on the lining 200. Afterwards, one or more of the airbags are depressurized, for example, the first airbags... Airbag 300, second airbag 400, or third airbag 500 are used to create unpressurized cavities in the outer wall of lining 200 at the depressurized airbags, simulating the back cavity of lining 200. Finally, train 700 moves along track 600 to simulate subway operation, and multiple vibration sensors on lining 200 are used to detect the vibration parameters of lining 200. By changing the position and number of depressurized airbags, the influence of back cavities of different positions, sizes, and numbers on lining 200 during train 700 operation is verified.

[0042] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A vibration response model of a subway tunnel with a cavity behind the wall, characterized in that, include: The outer cylinder is arranged horizontally, and the outer cylinder is provided with an axially penetrating mounting hole; A lining is provided at the mounting hole, the lining having an axially penetrating tunnel, and an assembly space is formed between the outer wall of the lining and the inner wall of the mounting hole; An inflatable assembly includes a plurality of first airbags arranged sequentially along the circumference of the liner in the assembly space. Multiple vibration sensors are distributed at circumferential intervals along the lining; The track is laid at the bottom of the tunnel; The train moves along the track.

2. The vibration response model of a subway tunnel with a post-wall cavity according to claim 1, wherein, The inflation assembly also includes: Multiple second airbags are arranged sequentially along the circumference of the lining in the assembly space; Multiple third airbags are arranged sequentially along the circumference of the lining in the assembly space; The first airbag, the second airbag, and the third airbag are staggered along the axial direction of the lining, and the volumes of the first airbag, the second airbag, and the third airbag are different from each other.

3. The vibration response model of a subway tunnel with a post-wall cavity according to claim 2, wherein, The volumes of the first airbag, the second airbag, and the third airbag increase sequentially.

4. The vibration response model of a subway tunnel with a cavity behind the wall according to claim 3, characterized in that, The first airbag, the second airbag, and the third airbag are all arc-shaped. The arc length of the second airbag is equal to the arc length of the third airbag, and the arc length of the second airbag is greater than the arc length of the first airbag.

5. The vibration response model of a subway tunnel with a cavity behind the wall according to claim 3, characterized in that, The thickness of the first airbag, the second airbag, and the third airbag gradually increases.

6. The vibration response model of a subway tunnel with a cavity behind the wall according to claim 2, characterized in that, The first airbag, the second airbag, and the third airbag are separated from each other.

7. The vibration response model of a subway tunnel with a cavity behind the wall according to claim 1, characterized in that, The sidewalls of the lining are divided into arch top, arch shoulder, arch waist, arch foot and arch bottom from top to bottom. The lining also includes a floating plate, which is movably installed at the arch bottom. Multiple vibration sensors are installed one-to-one at the arch top, arch shoulder, arch waist, arch foot and floating plate.

8. The vibration response model of a subway tunnel with a cavity behind the wall according to claim 1, characterized in that, The vibration response model also includes: Multiple pressure sensors are provided, with one pressure sensor located between each of the first airbags and the outer wall of the lining.

9. The vibration response model of a subway tunnel with a cavity behind the wall according to claim 1, characterized in that, At least one of the vibration sensors is located on the train.

10. The vibration response model of a subway tunnel with a cavity behind the wall according to claim 1, characterized in that, The vibration response model also includes: Multiple strain sensors are distributed at circumferential intervals along the lining.

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