A fault-crossing tunnel model experiment lining active protection device and protection method

Abstract

The present application relates to the technical fields of tunnel engineering test, and discloses a kind of through fault tunnel model experiment lining active protection device and protection method, set in tunnel lining interior, the through fault tunnel model experiment lining active protection device includes inflatable air cushion main body, subsection air charging and discharging component, active sensing adjustment component and flexible curvature compensation connecting component, the inflatable air cushion main body includes sealed air cushion chamber and separation component, the separation component is spaced apart and arranged in sealed air cushion chamber interior;The subsection air charging and discharging component is respectively communicated with first sealed air cushion, second sealed air cushion and third sealed air cushion respectively;The active sensing adjustment component is used to respectively collect the cavity information of first sealed air cushion, second sealed air cushion and third sealed air cushion;The flexible curvature compensation connecting component is arranged at the connecting place of first sealed air cushion and second sealed air cushion and the connecting place of second sealed air cushion and third sealed air cushion.

Description

Technical Field

[0001] This invention relates to the field of tunnel engineering testing technology, and in particular to an active protection device and method for the lining of a fault-crossing tunnel model experiment. Background Technology

[0002] As transportation infrastructure continues to extend into complex mountainous areas and active tectonic zones, tunnel engineering inevitably needs to traverse areas with complex geological conditions, such as fault fracture zones, alternating layers of soft and hard rock, and strongly weathered zones. To reveal the interaction mechanisms between tunnels, faults, and surrounding rock under faulting, vibration, or long-term non-uniform confining pressure, and to verify the effectiveness of technical solutions such as flexible buffer layers, waterproof joints, and fault-resistant structures, large-scale indoor model box physical simulation tests have become an important means of studying tunnel fault resistance.

[0003] Because the tunnel lining spans three strata with significantly different physical properties—the hanging wall, footwall, and fault fracture zone—stress concentration occurs at the interfaces between these strata due to differences in stiffness during compaction. Existing lining protective airbags or temporary support structures are mostly monolithic airbags or single pressure equalizing chambers, typically providing only uniform support pressure to the lining's interior. This makes it difficult to differentiate and compensate for the non-uniform confining pressure caused by varying strata stiffness and filling heights during cross-fault tests, and also hinders the maintenance of continuous fit in the transitional areas connecting the hanging wall, fault fracture zone, and footwall. When the monolithic airbag is under tension and local lining curvature changes, hard spots, wrinkles, voids, or localized top pressure can easily appear at the airbag connections, affecting experimental results. Summary of the Invention

[0004] In order to overcome at least one of the defects of the prior art, the present invention provides an active protection device and method for the lining of a fault-crossing tunnel model experiment, which enables the tunnel lining to be supported in sections according to different strata in the fault-crossing model experiment, thereby improving the realism and stability of the fault-crossing tunnel model experiment.

[0005] In a first aspect, this application provides an active protection device for the lining of a fault-crossing tunnel model experiment. The active protection device includes an inflatable air cushion body, a segmented inflation / deflation assembly, an active sensing and adjustment assembly, and a flexible curvature compensation connection assembly. The inflatable air cushion body is arranged along the axial direction of the tunnel lining. The inflatable air cushion body includes a sealed air cushion chamber and a partition component. The partition component is spaced apart inside the sealed air cushion chamber to divide the sealed air cushion chamber into a first sealed air cushion corresponding to the upper plate section of the model box test, a second sealed air cushion corresponding to the fault fracture zone section of the model box test, and a third sealed air cushion corresponding to the lower plate section of the model box test. The segmented inflation / deflation assembly is respectively connected to the first sealing gasket, the second sealing gasket, and the third sealing gasket, so as to inflate or deflate the first sealing gasket, the second sealing gasket, and the third sealing gasket respectively; The active sensing and adjustment component is used to collect cavity information of the first sealing air cushion, the second sealing air cushion and the third sealing air cushion respectively, and to perform pressure compensation based on the cavity information; The flexible curvature compensation connection component is disposed at the connection between the first sealing air pad and the second sealing air pad, and at the connection between the second sealing air pad and the third sealing air pad, so that when the curvature of the connection between the first sealing air pad and the second sealing air pad, and the connection between the second sealing air pad and the third sealing air pad, is changed, it remains in close contact with the tunnel lining.

[0006] In one embodiment, the active protection device further includes a positioning rod, a positioning end plate, and a locking element, wherein, The positioning rod extends axially through the inflatable air cushion body and is used to guide the inflatable air cushion body axially and limit its radial movement. The positioning rod is a hollow rod, and the hollow rod has independent first airflow channel, second airflow channel and third airflow channel inside. The positioning end plate is disposed at one end of the inflatable air cushion body and forms a limiting fit with the end of the tunnel lining to limit the installation position of the inflatable air cushion body inside the tunnel lining. The locking element is disposed between the positioning rod and the positioning end plate, and is used to lock the positioning end plate onto the positioning rod.

[0007] In one embodiment, the surface of the positioning rod is provided with length scale lines, which are used to axially align the first sealing air cushion, the second sealing air cushion, and the third sealing air cushion with the upper plate segment, the fault fracture zone segment, and the lower plate segment, respectively.

[0008] In one embodiment, the segmented inflation / deflation assembly includes an upper plate valve vent pipe, a fault fracture zone valve vent pipe, a lower plate valve vent pipe, a pressure regulating valve, and a pressure relief port, wherein, The upper valve vent pipe is connected to the first sealing gasket through the first airflow channel; The fault fracture zone vent pipe is connected to the second sealing air cushion through the second airflow channel; The lower plate valve vent pipe is connected to the third sealing gasket through the third airflow channel; The pressure regulating valves are respectively disposed on the first airflow channel, the second airflow channel and the third airflow channel; The pressure relief port is connected to the first sealing gasket, the second sealing gasket, and the third sealing gasket, respectively.

[0009] In one embodiment, the active sensing and adjustment component includes a data acquisition unit, a cavity pressure sensor, a contact pressure sensor, a deformation detection sensor, and a vibration detection sensor, wherein, The cavity pressure sensors are respectively disposed in the first sealing air pad, the second sealing air pad, and the third sealing air pad, and are used to detect the cavity pressure in the first sealing air pad, the second sealing air pad, and the third sealing air pad; The contact pressure sensor is disposed at the connection between the first sealing air pad and the second sealing air pad, and at the connection between the second sealing air pad and the third sealing air pad, and is used to detect whether the inflatable air pad body is in contact with the inner wall of the tunnel lining. The deformation detection sensor is disposed on the outer surface of the inflatable air cushion body and is used to obtain deformation information of the tunnel lining or the inflatable air cushion body during the filling and vibration process. The vibration detection sensor is disposed on the outer surface of the inflatable air cushion body and is used to acquire vibration information of the tunnel lining or the inflatable air cushion body during the filling and vibration process. The data acquisition unit is electrically connected to the cavity pressure sensor, the contact pressure sensor, the deformation detection sensor, and the vibration detection sensor, and is used to acquire cavity pressure information, contact pressure information, deformation information, and vibration information.

[0010] In one embodiment, the active sensing and adjustment component further includes an early warning unit and a controller, wherein, The controller is electrically connected to the data acquisition unit, the pressure regulating valve, and the pressure relief port. The controller is used to generate compensation pressure information for the first sealing air cushion, the second sealing air cushion, and the third sealing air cushion based on the cavity pressure information, contact pressure information, deformation information, and vibration information, and to control the pressure regulating valve and the pressure relief port to inflate or deflate. The early warning unit is electrically connected to the controller, and the early warning unit is used to issue an early warning signal when the cavity pressure information exceeds a preset pressure threshold, the contact pressure information exceeds a preset differential pressure threshold, the deformation information exceeds a preset deformation threshold, or the vibration information exceeds a preset vibration threshold.

[0011] In one embodiment, the flexible curvature compensation connection assembly includes a corrugated circumferential flexible capsule wall disposed on the outer surface of the separator assembly, and the corrugated circumferential flexible capsule wall is fixedly connected to the separator assembly.

[0012] In one embodiment, the outer surface of the inflatable air cushion body is provided with a friction-reducing layer, which is used to reduce the frictional resistance when the inflatable air cushion body is placed into the tunnel lining or removed from the tunnel lining.

[0013] In one embodiment, a clamping steel ring is provided at the connection between the corrugated circumferential flexible bladder wall and the separator component to improve the airtight isolation effect.

[0014] Secondly, this application provides an active protection method for the lining of a fault-crossing tunnel model experiment, employing the aforementioned active protection device for the lining of a fault-crossing tunnel model experiment. The protection method includes the following steps: Based on the axial positions of the upper section, fault fracture zone section, and lower section relative to the tunnel lining, the support positions of the first sealing air cushion, the second sealing air cushion, and the third sealing air cushion inside the tunnel lining are determined. The inflatable air cushion body is placed inside the tunnel lining along the tunnel lining axis, with the first sealing air cushion corresponding to the upper plate section, the second sealing air cushion corresponding to the fault fracture zone section, and the third sealing air cushion corresponding to the lower plate section. The first sealing air cushion, the second sealing air cushion and the third sealing air cushion are inflated by the segmented inflation and deflation assembly, so that the main body of the inflatable air cushion forms an initial fit and support with the inner wall of the tunnel lining. The active sensing and adjustment components acquire cavity information of the first sealing air cushion, the second sealing air cushion, and the third sealing air cushion respectively, and generate compensation pressure information of the first sealing air cushion, the second sealing air cushion, and the third sealing air cushion respectively based on the cavity information. According to the compensation pressure information, the first sealing air cushion, the second sealing air cushion and the third sealing air cushion are respectively controlled to inflate or depressurize, so that the first sealing air cushion, the second sealing air cushion and the third sealing air cushion respectively provide the tunnel lining with internal support pressure that is compatible with the external confining pressure of the upper section, the fault fracture zone section and the lower section. When the support state of the tunnel lining inner wall changes at the connection between the first and second sealing air cushions and at the connection between the second and third sealing air cushions, the connection deformation is compensated by the flexible curvature compensation connection component to maintain the fit with the tunnel lining inner wall. When the cavity information exceeds the corresponding preset safety conditions, the active sensing and adjustment component outputs a warning signal and controls the segmented inflation and deflation component to correct the pressure of the corresponding sealing gasket. After the tunnel lining is under stable stress, the first, second and third sealing air cushions are depressurized respectively, causing the main body of the inflatable air cushion to shrink and separate from the inner wall of the tunnel lining. Then the main body of the inflatable air cushion is extracted from the inside of the tunnel lining.

[0015] In summary, the active protection device and method for the lining of a fault-crossing tunnel model experiment provided by this invention have the following advantages over the prior art: (1) The first sealing air cushion, the second sealing air cushion and the third sealing air cushion correspond to the upper plate segment, the fault fracture zone segment and the lower plate segment respectively, which can provide differentiated support for the confining pressure difference of different strata segments; the flexible curvature compensation connection component is set at the connection of adjacent sealing air cushions, which can maintain fit when the lining curvature changes or the support state changes in the transition area, avoiding the generation of hard points, wrinkles, gaps or local top pressure in the connection transition area of ​​traditional integral airbags; (2) By setting positioning tie rods, positioning end plates, and locking components, the inflatable air cushion body has clear axial guidance, radial limitation, and end positioning foundation when placed inside the tunnel lining, which can reduce the risk of air cushion body offset, tilting, or misalignment during installation. The positioning tie rods are hollow rods and are equipped with a first airflow channel, a second airflow channel, and a third airflow channel. They can not only undertake positioning and guiding functions, but also provide an independent air path foundation for different sealing air cushions, making the device structure more compact and facilitating its arrangement and removal inside the narrow tunnel lining model.

[0016] (3) By setting up cavity pressure sensors, contact pressure sensors, deformation detection sensors and vibration detection sensors, the active sensing and adjustment components can obtain test process information from multiple dimensions such as cavity pressure, air cushion fit status, lining or air cushion deformation and filling vibration response, so as to ensure the accuracy and authenticity of the test. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is an axial cross-sectional view of the first sealing air cushion of the active protection device for the lining of a tunnel model experiment through a fault according to an embodiment of this application. Figure 2 This is an axial cross-sectional view of the second sealing air cushion of the active protection device for the lining of a tunnel model experiment through a fault according to an embodiment of this application; Figure 3 This is an axial cross-sectional view of the second sealing air cushion of the active protection device for the lining of a tunnel model experiment through a fault according to an embodiment of this application; Figure 4 This is a transverse sectional view of an active protection device for the lining of a tunnel model experiment through a fault according to an embodiment of this application; Figure 5 This is a partial enlarged view of the positioning end plate of the active protection device for the lining of a tunnel model experiment through a fault according to an embodiment of this application; Figure 6 This is a cross-sectional view of an active protection device for the lining of a tunnel model experiment through a fault according to an embodiment of this application; Figure 7 This is a schematic diagram of the connection of the active sensing and adjustment component of the active protection device for the lining of a tunnel model experiment crossing a fault according to an embodiment of this application; Figure 8 This is a schematic planar structural diagram of the flexible curvature compensation connection component of the active protection device for the lining of a tunnel crossing a fault, according to an embodiment of this application.

[0019] Figure 9 This is a structural block diagram of the controller of the active protection device for the lining of a tunnel model experiment through a fault according to an embodiment of this application.

[0020] The meanings of the reference numerals in the attached drawings are as follows: 1. Inner lining of tunnel; 2. Outer lining of tunnel; 3. Hoop steel ring; 4. Main body of inflatable air cushion; 5. Locking component; 6. Positioning tie rod; 7. Positioning end plate; 8. Separation assembly; 9. Upper plate air valve vent pipe; 10. Fault fracture zone air valve vent pipe; 11. Lower plate air valve vent pipe; 12. Upper plate section; 13. Fault fracture zone section; 14. Lower plate section; 15. First sealing air cushion; 16. Second sealing air cushion; 17. Third sealing air cushion; 18. Data acquisition unit; 19. Early warning unit; 20. Pressure regulating valve; 21. Pressure relief port; 22. Corrugated circumferential flexible bladder wall; 23. Cavity pressure sensor; 24. Contact pressure sensor; 25. Deformation detection sensor; 26. Vibration detection sensor; 27. Controller. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0022] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0023] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" 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 the embodiments of the present invention 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 the embodiments of the present invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] Embodiments of the present invention are described in detail below, examples of which are illustrated 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 intended to explain the present invention, and should not be construed as limiting the present invention.

[0026] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0027] In one embodiment, see Figures 1-9As shown, this invention discloses an active protection device for the lining of a fault-crossing tunnel model experiment. The device is installed inside the tunnel lining, which includes an inner lining and an outer lining. The inner lining is the inner wall of the tunnel lining, and the outer lining is the outer wall. It is suitable for tunnel lining models spanning the upper section 12, fault fracture zone section 13, and lower section 14 of a model box test. The active protection device is placed in the cavity enclosed by the inner lining 1 during the test preparation stage. It provides adjustable internal support pressure to the lining model during the layered filling, compaction, and vibration of similar surrounding rock materials. The pressure is released and removed after the external soil filling has stabilized, thus preventing the lining model from developing cracks, scratches, local instability, or micro-cracks before the formal fault slip test. The active protection device for the fault-crossing tunnel model lining includes an inflatable air cushion body, a segmented inflation and deflation assembly, an active sensing and adjustment assembly, a flexible curvature compensation connection assembly, a positioning tie rod 6, a positioning end plate 7, and a locking element 5.

[0028] Specifically, the inflatable air cushion body 4 is a cylindrical structure extending along the tunnel lining axis, and its outer contour matches the shape of the inner wall of the tunnel lining 1. Depending on the cross-sectional shape of the tunnel lining, the inflatable air cushion body 4 can also be made into other shapes that are compatible with the cross-section of the tunnel lining. When not inflated, the inflatable air cushion body 4 is in a foldable or flattenable state, which is convenient for insertion from the end of the tunnel lining or the observation window of the model box. After inflation, the outer surface of the inflatable air cushion body 4 expands outward and fits into the tunnel lining 1, thereby forming a support surface inside the lining.

[0029] The inflatable air cushion body 4 includes a sealed air cushion chamber and a partition component 8. The sealed air cushion chamber is the internal space of the inflatable air cushion body 4. The partition component 8 is spaced apart inside the sealed air cushion chamber and is arranged radially along the inflatable air cushion body 4. It is also sealed to the inner wall of the inflatable air cushion body 4. In this embodiment, there are two partition components 8 to divide the sealed air cushion chamber into a first sealed air cushion 15 corresponding to the upper plate segment 12 of the model box test, a second sealed air cushion 16 corresponding to the fault fracture zone segment 13 of the model box test, and a third sealed air cushion 17 corresponding to the lower plate segment 14 of the model box test. The partition component 8 is made of flexible composite material, or it can be made of flexible rubber sheet, coated fiber cloth, or multi-layer airtight membrane. The partition component 8 and the inner wall of the inflatable air cushion body 4 can be connected by high-frequency heat sealing, hot-press welding, adhesive sealing, sewing and then applying adhesive sealing, or integral molding to ensure airtight isolation between adjacent sealed air cushions. The first sealing air cushion 15, the second sealing air cushion 16, and the third sealing air cushion 17 can each form an independent support unit. Since the stiffness, filling height, compaction strength, and vibration response of similar materials in the upper plate segment 12, the fault fracture zone segment 13, and the lower plate segment 14 may be different, the internal pressure of the three sealing air cushions can be adjusted respectively, so that each stratum segment obtains a support force that is compatible with the external confining pressure, ensuring the reliability of the support.

[0030] It should also be noted that the inflatable air cushion body 4 is made of a high-strength and tough composite fiber flexible material, such as polyester fiber cloth, aramid fiber cloth, nylon reinforced cloth or glass fiber reinforced cloth. With the above materials, the inflatable air cushion body 4 has sufficient tensile strength and tear resistance, and can also rely on its own elasticity to shrink back after depressurization, making it easy to remove without damage.

[0031] Specifically, the flexible curvature compensation connection assembly is disposed at the connection between the first sealing air pad 15 and the second sealing air pad 16, and at the connection between the second sealing air pad 16 and the third sealing air pad 17, so that when the curvature of the connection between the first sealing air pad 15 and the second sealing air pad 16, and at the connection between the second sealing air pad 16 and the third sealing air pad 17 changes, it remains in close contact with the tunnel lining.

[0032] The flexible curvature compensation connection component includes a corrugated circumferential flexible bladder wall 22, which is disposed on the outer surface of the separator component 8. The separator component 8 is a partition. The corrugated circumferential flexible bladder wall 22 is composed of multiple circumferential folds. The length of the separator component 8 is much smaller than the length of the corrugated circumferential flexible bladder wall 22. The separator component 8 is disposed in the middle of the multiple circumferential folds. This design allows the circumferential folds on one side to communicate with one of the sealing air cushions (such as the first sealing air cushion 15), and the circumferential folds on the other side to communicate with another sealing air cushion (such as the second sealing air cushion 16). The axial expansion and contraction stiffness of the corrugated circumferential flexible bladder wall 22 is less than the axial expansion and contraction stiffness of the main body segments of the first sealing air cushion 15, the second sealing air cushion 16, and the third sealing air cushion 17.

[0033] It should be noted that when the target pressures of two adjacent sealing air cushions (such as the first sealing air cushion 15 and the second sealing air cushion 16) are different, or when the tunnel lining experiences a local curvature abrupt change near the fault fracture zone 13, the corrugated circumferential flexible bladder wall 22 can absorb the geometric differences at the connection of adjacent chambers by deforming through fold expansion or fold contraction. This allows the connection of adjacent sealing air cushions to remain in close contact with the inner lining 1 of the tunnel lining, thus avoiding the formation of hard spots, wrinkles, gaps, or local pressure at the junction of adjacent chambers and reducing stress concentration in the junction area of ​​the upper plate 12, the fault fracture zone 13, and the lower plate 14.

[0034] The corrugated circumferential flexible capsule wall 22 is fixedly connected to the separator component 8. Specifically, the fixed connection between the corrugated circumferential flexible capsule wall 22 and the separator component 8 can be achieved by heat sealing, bonding, integral molding, or compression sealing.

[0035] It should also be noted that a clamping steel ring 3 is provided at the connection between the corrugated circumferential flexible bladder wall 22 and the partition component 8 to improve the airtight isolation effect. Specifically, the clamping steel ring 3 is positioned exactly on the outer surface of the partition plate of the partition component 8, and the circumferential clamping force improves the airtight isolation effect at the connection of the partition component 8. By setting this, the sealing reliability near the partition component 8 can be maintained when there is a pressure difference between adjacent chambers, preventing gas cross-contamination; it can also provide a flexible transition when the inner wall of the lining undergoes local bending, ellipticization, or slight deformation, so that the internal support pressure gradually transitions along the axial direction, rather than changing abruptly at the position of the partition component 8, thereby improving the realism and stability of the lining stress state in the model test.

[0036] Specifically, the positioning rod 6 passes through the inflatable air cushion body 4 along the axial direction. The positioning rod 6 is located in the central area of ​​the inflatable air cushion body 4. The positioning rod 6 is used to guide the inflatable air cushion body 4 axially and limit its radial movement during the insertion, positioning, inflation support, depressurization and removal of the device, so as to prevent the inflatable air cushion body 4 from twisting, deflecting or partially folding inside the tunnel lining.

[0037] It should also be noted that the positioning rod 6 can be a stainless steel hollow rod, an aluminum alloy hollow rod, a carbon fiber composite rod, or an engineering plastic reinforced rod, which can meet the requirements of axial pull-out and push strength while reducing the overall weight of the device.

[0038] In one specific embodiment, the positioning rod 6 is a hollow rod, and the hollow rod has three independent airflow channels: a first airflow channel, a second airflow channel, and a third airflow channel. The first airflow channel is connected to the first sealing air cushion 15, the second airflow channel is connected to the second sealing air cushion 16, and the third airflow channel is connected to the third sealing air cushion 17. The positioning rod 6 can also have reserved signal line channels for laying sensor signal lines, integrating the air path and wiring into the same central rod, thereby reducing the number of pipelines inside the tunnel lining and improving the simplicity of the device layout.

[0039] The positioning tie rod 6 has length scale lines on its surface. These scale lines are used to align the first sealing air cushion 14, the second sealing air cushion 15, and the third sealing air cushion 16 with the upper plate segment 11, the fault fracture zone segment 12, and the lower plate segment 13, respectively. Operators can read the scale lines on the surface of the positioning tie rod 6 based on the axial positions of the upper plate segment 12, the fault fracture zone segment 13, and the lower plate segment 14 relative to the tunnel lining within the model box. This ensures that the first sealing air cushion 15, the second sealing air cushion 16, and the third sealing air cushion 17 are aligned with their corresponding stratum sections. This avoids misalignment of the chambers caused by manual visual inspection and improves the repeatability and comparability of cross-fault model tests.

[0040] Specifically, the positioning end plate 7 is disposed at one end of the inflatable air cushion body 4, and the positioning end plate 7 is disc-shaped. The outer diameter of the positioning end plate 7 is smaller than the inner cavity size of the tunnel lining 1, so that it can form a limiting fit with the end of the tunnel lining; the central area of ​​the positioning end plate 7 is provided with a through hole or threaded hole for the positioning tie rod 6 to pass through. The positioning end plate 7 can be made of aluminum alloy, stainless steel, nylon, polyoxymethylene or glass fiber reinforced plastic, and a rubber buffer pad can be provided on its side facing the tunnel lining end face to avoid rigid collision between the positioning end plate 7 and the brittle lining end face.

[0041] Specifically, the locking element 5 is located between the positioning tie rod 6 and the positioning end plate 7. The locking element 5 is a threaded locking nut. When the positioning end plate 7 is adjusted to the predetermined position, the locking element 5 locks the positioning end plate 7 onto the positioning tie rod 6, maintaining a stable axial relative position between the positioning end plate 7 and the inflatable air cushion body 4. The locking element 5 prevents the positioning end plate 7 from loosening during inflation and filling, ensuring that the device does not experience axial movement due to external vibration or internal pressure changes.

[0042] Specifically, the segmented inflation / deflation assembly is connected to the first sealing gasket 15, the second sealing gasket 16, and the third sealing gasket 17 respectively, to inflate or deflate the first sealing gasket 15, the second sealing gasket 16, and the third sealing gasket 17 respectively; the segmented inflation / deflation assembly includes an upper plate valve vent pipe 9, a fault fracture zone valve vent pipe 10, a lower plate valve vent pipe 11, a pressure regulating valve 20, and a pressure relief port 21. The upper plate valve vent pipe 9 is connected to the first sealing gasket 15 through a first airflow channel, the fault fracture zone valve vent pipe 10 is connected to the second sealing gasket 16 through a second airflow channel, and the lower plate valve vent pipe 11 is connected to the third sealing gasket 17 through a third airflow channel. The upper plate valve vent pipe 9, the fault fracture zone valve vent pipe 10, and the lower plate valve vent pipe 11 are made of silicone hoses and are equipped with quick-connect plugs at the ends for quick connection to external air sources and pressure regulating valve groups.

[0043] The pressure regulating valves 20 are respectively installed on the air lines of the first airflow channel, the second airflow channel and the third airflow channel. The pressure regulating valves are proportional pressure regulating valves to achieve automated operation. They can continuously adjust the opening degree according to the control signal output by the controller 27 so that the pressure of each sealing air cushion chamber gradually approaches the target compensation pressure. The pressure relief port 21 is connected to the first sealing air cushion 15, the second sealing air cushion 16 and the third sealing air cushion 17 respectively. The pressure relief port 21 is equipped with a controllable pressure relief valve, a one-way pressure relief valve or a safety pressure relief valve to release gas when the pressure is too high, the pressure difference is too large or the test ends.

[0044] In use, the external air source can be an air pump. The gas output from the external air source enters the first sealing air cushion 15, the second sealing air cushion 16, and the third sealing air cushion 17 respectively through the pressure regulating valve 20. Since the first, second, and third air flow channels are independent of each other, the inflation, stabilization, or depressurization of any sealing air cushion will not directly affect the other sealing air cushions. This allows for differentiated support for the upper section 11, the fault fracture zone section 12, and the lower section 13. This design can establish different support pressures according to the filling height, compaction state, and external confining pressure differences of different strata sections. When the support requirements change near the fault fracture zone section 13 due to material loosening or local deformation, the second sealing air cushion 16 can be individually replenished or depressurized without changing the overall pressure of the first and third sealing air cushions 15 and 17, thereby improving the pressure regulation accuracy and reducing disturbance to other sections.

[0045] Specifically, the active sensing and adjustment component is used to collect cavity information of the first sealing air cushion 15, the second sealing air cushion 16, and the third sealing air cushion 17 respectively, and to perform pressure compensation based on the cavity information. The active sensing and adjustment component includes a data acquisition unit 18, a cavity pressure sensor 23, a contact pressure sensor 24, a deformation detection sensor 25, a vibration detection sensor 26, a controller 27, and an early warning unit 19.

[0046] Among them, three cavity pressure sensors 23 are provided, which are respectively installed in the first sealing air pad 15, the second sealing air pad 16 and the third sealing air pad 17. They are used to detect the cavity pressure of the corresponding sealing air pad in real time. The cavity pressure sensors 23 are either air pressure sensors or thin film pressure sensors. The cavity pressure sensors 23 are arranged near the outlet of the corresponding airflow channel to improve the response speed of pressure detection.

[0047] The contact pressure sensor 24 is located at the connection between the first sealing air cushion 15 and the second sealing air cushion 16, and at the connection between the second sealing air cushion 16 and the third sealing air cushion 17. It can also be placed on the outer surface of the inflatable air cushion body 4. The contact pressure sensor 24 is a flexible thin-film pressure sensor, a piezoresistive sensor, or a capacitive flexible pressure plate, used to detect whether an effective fit is formed between the inflatable air cushion body 4 and the tunnel lining lining 1. When the contact pressure is lower than the fit threshold, it indicates that there may be a void at the corresponding position; when the contact pressure suddenly increases, it indicates that there may be local pressure or external vibration impact at that position.

[0048] The deformation detection sensor 25 is disposed on the outer surface of the inflatable air cushion body 4 and is used to obtain deformation information of the tunnel lining or the inflatable air cushion body 4 during the filling and vibration process. The deformation detection sensor 25 can be a strain gauge, flexible strain sensing strip, fiber optic grating sensor, displacement sensor or other element capable of detecting deformation.

[0049] The vibration detection sensor 26 is installed on the outer surface of the inflatable air cushion body 4 or on the positioning tie rod 6 to obtain vibration information during the filling and compaction process. The vibration detection sensor 26 can be an acceleration sensor or a vibration sensor.

[0050] The data acquisition unit 18 is electrically connected to the cavity pressure sensor 23, contact pressure sensor 24, deformation detection sensor 25, and vibration detection sensor 26, and is used to collect cavity pressure information, contact pressure information, deformation information, and vibration information. The data acquisition unit 18 can be installed on the outside of the model box and connected to each sensor via signal lines; the signal lines can be fixedly arranged along the inside or outside of the positioning rod 6 to prevent them from being scratched during the insertion and removal of the device.

[0051] The controller 27 is electrically connected to the data acquisition unit 18, the pressure regulating valve 20, and the pressure relief port 21. Based on the cavity pressure information, contact pressure information, deformation information, and vibration information collected by the data acquisition unit 18, the controller 27 generates compensation pressure information for the first sealing air cushion 15, the second sealing air cushion 16, and the third sealing air cushion 17, respectively, and controls the corresponding pressure regulating valve 20 and pressure relief port 21 to perform inflation, pressure stabilization, or pressure relief actions.

[0052] The early warning unit 19 is electrically connected to the controller 27. The early warning unit 19 may include a buzzer, indicator light, display screen, wireless communication module, or host computer alarm interface. When the pressure in any sealing air cushion cavity exceeds a preset pressure threshold, the pressure difference between adjacent sealing air cushions exceeds a preset pressure difference threshold, the contact pressure is lower than the bonding threshold or higher than the local pressure threshold, the deformation information exceeds a preset deformation threshold, or the vibration information exceeds a preset vibration threshold, the early warning unit 19 outputs an early warning signal, prompting the operator to suspend filling or adjust the compaction intensity, and controls the pressure regulating valve 20 and the pressure relief port 21 to correct the pressure in the corresponding cavity. This design, by simultaneously acquiring the cavity pressure, bonding status, deformation response, and vibration response, can more accurately determine whether the forces inside and outside the tunnel lining are balanced, avoiding the lining being crushed by the external soil due to insufficient support, and also avoiding the lining being pushed outward by the air cushion due to excessive internal support.

[0053] It should also be noted that the outer surface of the inflatable air cushion body 4 is provided with a friction-reducing layer, which can be a polytetrafluoroethylene coating or a polyurethane wear-resistant layer. The friction-reducing layer covers the outer surface of the inflatable air cushion body 4 that contacts the tunnel lining 1, and is used to reduce the frictional resistance when the device is inserted and removed. For brittle lining models such as gypsum or microconcrete, the friction-reducing layer can also reduce scratching and pulverization, and maintain the integrity of the inner surface of the lining.

[0054] In the preparation stage of the cross-fault tunnel model test, the tunnel lining model is located between the upper platen 12, the fault fracture zone 13, and the lower platen 14 within the model box. During the layered filling and vibration of the surrounding rock with similar materials, the exterior of the lining model is subjected to gradually increasing static confining pressure and periodic vibration dynamic load. If the interior of the lining model remains in a hollow state, it is prone to local deformation, fatigue micro-cracks, or shear damage. This invention addresses this by setting up segmented, independently pressure-controlled inflatable air cushion bodies 4 inside the lining, allowing the air cushions to provide a reverse support force to the inner wall of the lining that matches the external confining pressure, thereby placing the lining wall in a relatively balanced stress state. The first sealing air cushion 15 is used to support the lining portion located in the upper platen 12, the third sealing air cushion 17 is used to support the lining portion located in the lower platen 14, and the second sealing air cushion 16 is used to support the lining portion located in the fault fracture zone 13. Since the filling material properties of the fault fracture zone 13 are different from those of the upper platen 12 and the lower platen 14, the target pressure of the second sealing air cushion 16 can be set independently. When the upper section 12 has a large filling height or high vibration intensity, the controller 27 increases the compensation pressure of the first sealing air cushion 15; when the fault fracture zone section 13 experiences a sudden change in contact pressure or abnormal deformation response, the controller 27 adjusts the pressure of the second sealing air cushion 16 separately; when the lower section 14 needs to maintain stable support, the third sealing air cushion 17 maintains a corresponding stable pressure state. At the transition between adjacent sections, the corrugated circumferential flexible bladder wall 22 absorbs the deformation differences caused by different air pressures and different lining curvatures, forming a flexible and continuous transition between the first sealing air cushion 15 and the second sealing air cushion 16, and between the second sealing air cushion 16 and the third sealing air cushion 17. This flexible transition prevents the air cushion connection from becoming a rigid node due to the presence of the partition 8, and also prevents voids from occurring at the lining curvature changes, thus ensuring a continuous distribution of support force along the tunnel axis. During the active closed-loop adjustment process, the data acquisition unit 18 continuously collects cavity pressure information, contact pressure information, deformation information, and vibration information for each chamber. The controller 27 compares the current chamber pressure with the target pressure, compares the contact pressure with the bonding threshold, and combines deformation and vibration response to determine whether the lining is in a safe state. When a chamber pressure is detected to be too low and the contact pressure is insufficient, the controller 27 increases the opening of the corresponding pressure regulating valve 20 to replenish air; when a chamber pressure is detected to be too high or the contact pressure is too high, the controller 27 decreases the opening of the pressure regulating valve 20 and opens the pressure relief port 21 to relieve pressure; when vibration exceeds the limit or the deformation rate is abnormal, the early warning unit 19 prompts to suspend filling or reduce the vibration intensity.

[0055] When the upper plate air valve vent pipe 9, the fault fracture zone air valve vent pipe 10, and the lower plate air valve vent pipe 11 inflate the corresponding chambers, the internal pressure of each sealed air cushion chamber gradually increases. The corrugated circumferential flexible bladder wall 22 is located in the transition area connecting adjacent chambers. Its inner side is also subjected to air pressure, which pushes the corrugated folds outward, causing the originally folded or corrugated bladder wall to produce a certain radial expansion and axial extension. The expansion is not an unlimited overall expansion like a regular balloon, but rather the corrugated folds are stretched open by air pressure. Because it is a continuous circumferential structure, after expansion, it can form a continuous fitting surface along the inner wall of the tunnel lining, avoiding steps, gaps, or hard top pressure between adjacent air cushion chambers. In the cross-fault model test, the confining pressure, stiffness, and deformation states of the upper plate segment 12, the fault fracture zone segment 13, and the lower plate segment 14 are different, and there may be a pressure difference between adjacent chambers. At this time, the corrugated circumferential flexible bladder wall 22 will undergo local bending, displacement and expansion and contraction according to the pressure difference between the two chambers and the curvature of the inner wall of the lining.

[0056] The expansion and contraction of the corrugated circumferential flexible bladder wall 22 are achieved by the combined effect of changes in chamber air pressure and the elastic recovery of the flexible material. When adjacent sealed air cushion chambers are inflated, the internal pressure of the chamber acts on the inner surface of the corrugated circumferential flexible bladder wall 22, causing the corrugated folds to unfold axially and bulge radially, thereby forming a deformable flexible transition support surface between adjacent sealed air cushion chambers. When there is a pressure difference between adjacent chambers or when the lining wall experiences a local curvature abrupt change near the fault fracture zone, the corrugated circumferential flexible bladder wall 22 compensates for the axial displacement, radial displacement, and angular deviation at the connection point through the local unfolding, compression, and bending of the folds, ensuring that the inflatable air cushion body 4 remains continuously fitted to the tunnel lining wall at the connection point. During depressurization, as the internal pressure of the chamber decreases, the corrugated circumferential flexible bladder wall 22 contracts and resets under its own elastic recovery force and the rebound effect of the folded structure, reducing the outer diameter at the connection point and lowering the extraction resistance.

[0057] Based on the same inventive concept, this application also provides an active protection method for the lining of a fault-crossing tunnel model experiment, employing the aforementioned active protection device for the lining of a fault-crossing tunnel model experiment, characterized in that the protection method includes the following steps: Based on the axial positions of the upper plate segment 12, the fault fracture zone segment 13, and the lower plate segment 14 relative to the tunnel lining, the support positions of the first sealing air cushion 15, the second sealing air cushion 16, and the third sealing air cushion 17 inside the tunnel lining are determined. The inflatable air cushion body 4 is placed inside the tunnel lining along the tunnel lining axis, and the first sealing air cushion 15 corresponds to the upper plate section 12, the second sealing air cushion 16 corresponds to the fault fracture zone section 13, and the third sealing air cushion 17 corresponds to the lower plate section 14. The first sealing air cushion 15, the second sealing air cushion 16 and the third sealing air cushion 17 are inflated by the segmented inflation and deflation assembly, so that the inflatable air cushion body 4 forms an initial fit and support with the inner wall of the tunnel lining. The active sensing and adjustment components acquire cavity information of the first sealing air cushion 15, the second sealing air cushion 16, and the third sealing air cushion 17 respectively, and generate compensation pressure information of the first sealing air cushion 15, the second sealing air cushion 16, and the third sealing air cushion 17 respectively based on the cavity information. According to the compensation pressure information, the first sealing air cushion 15, the second sealing air cushion 16 and the third sealing air cushion 17 are respectively controlled to inflate or deflate, so that the first sealing air cushion 15, the second sealing air cushion 16 and the third sealing air cushion 17 respectively provide the tunnel lining with internal support pressure that is compatible with the external confining pressure of the upper section 12, the fault fracture zone section 13 and the lower section 14. When the support state of the tunnel lining inner wall changes at the connection between the first sealing air cushion 15 and the second sealing air cushion 16 and at the connection between the second sealing air cushion 16 and the third sealing air cushion 17, the connection deformation is compensated by the flexible curvature compensation connection component to maintain the fit with the tunnel lining inner wall. When the cavity information exceeds the corresponding preset safety condition, the active sensing and adjustment component outputs a warning signal and controls the segmented inflation and deflation component to correct the pressure of the corresponding sealing gasket; wherein, the specific threshold information of the preset safety condition is selected according to the actual situation; After the tunnel lining is under stable stress, the first sealing air cushion 15, the second sealing air cushion 16 and the third sealing air cushion 17 are depressurized respectively, so that the inflatable air cushion body 4 shrinks and separates from the inner wall of the tunnel lining, and then the inflatable air cushion body 4 is extracted from the inside of the tunnel lining.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An active protection device for the lining of a fault-crossing tunnel model experiment, installed inside the tunnel lining, characterized in that, The active protection device for the lining of the fault-crossing tunnel model experiment includes an inflatable air cushion body (4), a segmented inflation and deflation assembly, an active sensing and adjustment assembly, and a flexible curvature compensation connection assembly, wherein... The inflatable air cushion body (4) is arranged along the axial direction of the tunnel lining. The inflatable air cushion body (4) includes a sealed air cushion chamber and a partition assembly (8). The partition assembly (8) is spaced apart inside the sealed air cushion chamber to divide the sealed air cushion chamber into a first sealed air cushion (15) corresponding to the upper plate section (12) of the model box test, a second sealed air cushion (16) corresponding to the fault fracture zone section (13) of the model box test, and a third sealed air cushion (17) corresponding to the lower plate section (14) of the model box test. The segmented inflation and deflation assembly is respectively connected to the first sealing air pad (15), the second sealing air pad (16) and the third sealing air pad (17) to inflate or deflate the first sealing air pad (15), the second sealing air pad (16) and the third sealing air pad (17) respectively. The active sensing and adjustment component is used to collect cavity information of the first sealing air cushion (15), the second sealing air cushion (16) and the third sealing air cushion (17) respectively, and to perform pressure compensation based on the cavity information; The flexible curvature compensation connection assembly is disposed at the connection between the first sealing air pad (15) and the second sealing air pad (16) and the connection between the second sealing air pad (16) and the third sealing air pad (17), so that when the curvature of the connection between the first sealing air pad (15) and the second sealing air pad (16) and the connection between the second sealing air pad (16) and the third sealing air pad (17) changes, it remains in close contact with the tunnel lining.

2. The active protection device for the lining of a fault-crossing tunnel model experiment according to claim 1, characterized in that, The active protection device also includes a positioning rod (6), a positioning end plate (7), and a locking component (5), wherein, The positioning rod (6) passes through the inflatable air cushion body (4) along the axial direction and is used to guide the inflatable air cushion body (4) axially and limit its radial movement. The positioning rod (6) is a hollow rod, and the hollow rod is provided with independent first airflow channel, second airflow channel and third airflow channel. The positioning end plate (7) is disposed at one end of the inflatable air cushion body (4) and forms a limiting fit with the end of the tunnel lining to limit the installation position of the inflatable air cushion body (4) inside the tunnel lining. The locking member (5) is disposed between the positioning rod (6) and the positioning end plate (7) for locking the positioning end plate (7) onto the positioning rod (6).

3. The active protection device for the lining of a fault-crossing tunnel model experiment according to claim 2, characterized in that, The surface of the positioning rod (6) is provided with length scale lines, which are used to axially align the first sealing air cushion (15), the second sealing air cushion (16) and the third sealing air cushion (17) with the upper plate section (12), the fault fracture zone section (13) and the lower plate section (14), respectively.

4. The active protection device for the lining of a fault-crossing tunnel model experiment according to claim 2, characterized in that, The segmented inflation / deflation assembly includes an upper plate valve vent pipe (9), a fault fracture zone valve vent pipe (10), a lower plate valve vent pipe (11), a pressure regulating valve (20), and a pressure relief port (21), wherein, The upper valve vent pipe (9) is connected to the first sealing gasket (15) through the first airflow channel; The fault fracture zone air valve vent pipe (10) is connected to the second sealing air cushion (16) through the second airflow channel; The lower valve vent pipe (11) is connected to the third sealing gasket (17) through the third airflow channel; The pressure regulating valve (20) is respectively disposed on the first airflow channel, the second airflow channel and the third airflow channel; The pressure relief port (21) is connected to the first sealing gasket (15), the second sealing gasket (16) and the third sealing gasket (17) respectively.

5. The active protection device and method for the lining of a fault-crossing tunnel model experiment according to claim 4, characterized in that, The active sensing and adjustment component includes a data acquisition unit (18), a cavity pressure sensor (23), a contact pressure sensor (24), a deformation detection sensor (25), and a vibration detection sensor (26), wherein, The cavity pressure sensor (23) is respectively disposed in the first sealing air pad (15), the second sealing air pad (16) and the third sealing air pad (17) to detect the cavity pressure in the first sealing air pad (15), the second sealing air pad (16) and the third sealing air pad (17); The contact pressure sensor (24) is located at the connection between the first sealing air pad (15) and the second sealing air pad (16) and at the connection between the second sealing air pad (16) and the third sealing air pad (17), and is used to detect whether the inflatable air pad body (4) is in contact with the inner wall of the tunnel lining; The deformation detection sensor (25) is disposed on the outer surface of the inflatable air cushion body (4) and is used to obtain the deformation information of the tunnel lining or the inflatable air cushion body (4) during the filling and vibration process. The vibration detection sensor (26) is disposed on the outer surface of the inflatable air cushion body (4) and is used to obtain vibration information of the tunnel lining or the inflatable air cushion body (4) during the filling and vibration process; The data acquisition unit (18) is electrically connected to the cavity pressure sensor (23), the contact pressure sensor (24), the deformation detection sensor (25) and the vibration detection sensor (26) for acquiring cavity pressure information, contact pressure information, deformation information and vibration information.

6. The active protection device for the lining of a fault-crossing tunnel model experiment according to claim 5, characterized in that, The active sensing and adjustment component further includes an early warning unit (19) and a controller (27), wherein, The controller (27) is electrically connected to the data acquisition unit (18), the pressure regulating valve (20), and the pressure relief port (21). The controller (27) is used to generate compensation pressure information for the first sealing air cushion (15), the second sealing air cushion (16), and the third sealing air cushion (17) based on the cavity pressure information, contact pressure information, deformation information, and vibration information, and to control the pressure regulating valve (20) and the pressure relief port (21) to inflate or deflate. The warning unit (19) is electrically connected to the controller (27). The warning unit (19) is used to issue a warning signal when the cavity pressure information exceeds a preset pressure threshold, the contact pressure information exceeds a preset differential pressure threshold, the deformation information exceeds a preset deformation threshold, or the vibration information exceeds a preset vibration threshold.

7. The active protection device for the lining of a fault-crossing tunnel model experiment according to claim 1, characterized in that, The flexible curvature compensation connection assembly includes a corrugated circumferential flexible capsule wall (22), which is disposed on the outer surface of the separator assembly (8) and is fixedly connected to the separator assembly (8).

8. The active protection device for the lining of a fault-crossing tunnel model experiment according to claim 1, characterized in that, The outer surface of the inflatable air cushion body (4) is provided with a friction-reducing layer, which is used to reduce the frictional resistance when the inflatable air cushion body (4) is placed into the tunnel lining or removed from the tunnel lining.

9. The active protection device for the lining of a fault-crossing tunnel model experiment according to claim 7, characterized in that, A tight-fitting steel ring (3) is provided at the connection between the corrugated circumferential flexible bladder wall (22) and the separator component (8) to improve the airtight isolation effect.

10. A method for active protection of the lining in a fault-crossing tunnel model experiment, employing the active protection device for the lining in a fault-crossing tunnel model experiment as described in any one of claims 1-9, characterized in that, The protection method includes the following steps: Based on the axial positions of the upper plate (12), the fault fracture zone (13), and the lower plate (14) relative to the tunnel lining, the support positions of the first sealing air cushion (15), the second sealing air cushion (16), and the third sealing air cushion (17) inside the tunnel lining are determined. The inflatable air cushion body (4) is placed inside the tunnel lining along the tunnel lining axis, and the first sealing air cushion (15) corresponds to the upper plate section (12), the second sealing air cushion (16) corresponds to the fault fracture zone section (13), and the third sealing air cushion (17) corresponds to the lower plate section (14). The first sealing air cushion (15), the second sealing air cushion (16) and the third sealing air cushion (17) are inflated by the segmented inflation and deflation assembly, so that the main body of the inflatable air cushion (4) forms an initial fit support with the inner wall of the tunnel lining. The active sensing and adjustment components acquire cavity information of the first sealing air cushion (15), the second sealing air cushion (16), and the third sealing air cushion (17) respectively, and generate compensation pressure information of the first sealing air cushion (15), the second sealing air cushion (16), and the third sealing air cushion (17) respectively based on the cavity information. According to the compensation pressure information, the first sealing air cushion (15), the second sealing air cushion (16) and the third sealing air cushion (17) are respectively controlled to be inflated or deflated, so that the first sealing air cushion (15), the second sealing air cushion (16) and the third sealing air cushion (17) provide the tunnel lining with internal support pressure that is compatible with the external confining pressure of the upper section (12), the fault fracture zone section (13) and the lower section (14); When the support state of the tunnel lining inner wall changes at the connection between the first sealing air cushion (15) and the second sealing air cushion (16) and at the connection between the second sealing air cushion (16) and the third sealing air cushion (17), the connection deformation is compensated by the flexible curvature compensation connection component to maintain the fit with the tunnel lining inner wall. When the cavity information exceeds the corresponding preset safety conditions, the active sensing and adjustment component outputs a warning signal and controls the segmented inflation and deflation component to correct the pressure of the corresponding sealing gasket. After the tunnel lining is under stable stress, the first sealing air cushion (15), the second sealing air cushion (16) and the third sealing air cushion (17) are depressurized respectively, so that the main body of the inflatable air cushion (4) shrinks and separates from the inner wall of the tunnel lining, and then the main body of the inflatable air cushion (4) is extracted from the inside of the tunnel lining.

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