Tunnel lining joint and dislocation adaptive control method capable of switching rigidity

Abstract

The invention relates to the field of tunnel engineering, in particular to a tunnel lining connector capable of switching rigidity and a dislocation adaptation control method, and provides the following scheme aiming at the problem that in the prior art, a tunnel lining connector cannot give consideration to normal use rigidity and fault dislocation large deformation adaptability at the same time. The sensor is installed on the lining section, the controller is connected with the sensor and used for distinguishing a normal use / small earthquake working condition and a fault large displacement dislocation working condition, and the connecting faces of the two sides of the lining section are correspondingly provided with an inserting groove and a containing hole respectively. Inserting blocks connected with the inserting grooves in an inserted mode and locking pieces used for locking the inserting blocks to limit rotation of the inserting blocks are installed in the containing holes, and lockable rigid mechanisms used for being connected with the inserting blocks are installed in the inserting grooves. Dynamic switching of the joint rigidity is achieved, the high-rigidity state is kept under the normal use / small-earthquake working condition, the flexible connection state is switched under the fault large-displacement dislocation working condition, and the use requirements under different working conditions are met.

Description

Technical Field

[0001] This invention relates to the field of tunnel engineering, and more particularly to a method for controlling the misalignment of a tunnel lining joint with switchable stiffness. Background Technology

[0002] In tunnel construction, the lining structure, as the core load-bearing component of the tunnel, directly affects the overall stability and durability of the tunnel due to the mechanical properties of its joints. Existing tunnel lining joints mostly adopt a fixed stiffness design, which has significant drawbacks: under normal use or minor earthquake conditions, the joints need high stiffness to ensure the integrity and load-bearing capacity of the tunnel structure and prevent excessive structural deformation; however, when encountering extreme conditions such as large displacement faults, the fixed high-stiffness joints cannot adapt to large deformations, easily leading to cracking, damage, or even failure, resulting in tunnel structural damage and seriously threatening traffic safety and the safety of personnel.

[0003] In existing technologies, while some flexible joints can adapt to certain deformations, their stiffness is insufficient under normal operating conditions, leading to a decrease in the overall load-bearing capacity of the tunnel structure. This fails to simultaneously meet the dual requirements of normal service stiffness and adaptability to large deformations caused by fault slippage. Furthermore, existing joints lack real-time operating condition identification and automatic response adjustment capabilities, making it difficult to dynamically adjust mechanical properties according to actual stress states, thus limiting their effectiveness in disaster prevention and mitigation. Therefore, this solution proposes a tunnel lining joint with switchable stiffness and a fault adaptation control method. Summary of the Invention

[0004] The present invention proposes a switchable stiffness tunnel lining joint and a fault adaptation control method, which solves the problem that the existing tunnel lining joints cannot simultaneously take into account the normal service stiffness and the adaptability to large deformation of fault faults.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A tunnel lining joint with switchable stiffness includes a lining section, a sensor installed on the lining section, and a controller connected to the sensor and used to distinguish between normal use / minor earthquake conditions and fault large displacement fault conditions. The two connecting surfaces of the lining section are respectively provided with slots and receiving holes. The receiving holes are equipped with plugs that are inserted into the slots and locking elements for locking the plugs to limit their rotation. The slots are equipped with lockable rigid mechanisms for connecting the plugs.

[0007] The lockable rigid mechanism includes two pressure plates disposed inside the slot, a drive assembly for adjusting the distance between the two pressure plates, and an anchoring assembly for anchoring the receiving hole under normal conditions. The two pressure plates form a connection space for connecting the plug. The drive assembly is connected to the controller so that, under the command of the controller, the two pressure plates are driven to move away from each other during fault large displacement fault conditions to increase the connection space and form a flexible connection state. Under normal use / minor earthquake conditions, the size of the connection space remains unchanged to maintain a high rigidity state.

[0008] The anchoring component cooperates with the driving component to release the anchoring of the storage hole when the connection space is increased;

[0009] The pressure plate is equipped with a toggle component for moving the insert into the slot when the drive component is operating to increase the connection space. The toggle component cooperates with the locking component to release the locking member from the insert when the connection space is increased, and cooperates with the lockable rigid mechanism to change to a flexible connection state.

[0010] The above technical solution enables dynamic switching of joint stiffness. It maintains high stiffness under normal use / minor earthquake conditions to ensure the integrity and load-bearing capacity of the tunnel structure. Under fault displacement and fault slip conditions, it switches to a flexible connection state, dissipates energy through deformation, effectively adapts to large deformations, avoids joint cracking and damage, and takes into account the usage requirements under different working conditions.

[0011] As a further improvement to the above solution, the inner walls of both long sides of the storage hole are provided with sliding grooves along their length direction. The locking component includes a mounting shaft fixed along the width direction of the insert block at one end located inside the storage hole and a limiting plate fixed on the inner wall of the storage hole on the side facing the opening. The limiting plate is arranged along the length direction of the mounting shaft. A limiting groove for inserting the limiting plate is provided on the outer periphery of the mounting shaft. Both ends of the mounting shaft extend into the two sliding grooves and slide with them. A return spring is fixed between the outer periphery of the mounting shaft at one end inside the sliding groove and the inner wall of the sliding groove on the side away from the limiting plate.

[0012] As a further improvement to the above solution, the two long sides of the slot are provided with side grooves along their length direction. The drive assembly is provided in two sets and is respectively located in the two side grooves. The drive assembly includes a bidirectional screw rotatably connected inside it along the height direction of the side groove and two side plates respectively threaded onto the outside of the bidirectional screw. The two side plates are respectively fixed to the sides of the two pressure plates. The bottom of the bidirectional screw extends to the bottom of the lining section. The drive assembly also includes a transmission component installed on the bottom surface of the lining section for driving the bidirectional screw to rotate.

[0013] As a further improvement to the above solution, a transmission gear is fixed at the bottom of the bidirectional screw and is coaxially arranged therewith. The transmission component includes a telescopic component installed on the bottom surface of the lining section and a transmission rack fixed on the extended section of the telescopic component. The transmission rack meshes with the transmission gear.

[0014] As a further improvement to the above solution, the anchoring assembly includes a fixed shaft rotatably connected inside the slot along the width direction, multiple connecting plates fixed to its outer periphery along the radial direction of the fixed shaft, and two adjusting rods. The end of the connecting plate away from the fixed shaft extends to the outside of the slot, and a locking block is fixed on the bottom surface of the connecting plate at the outside end of the slot. The bottom surface of the receiving hole is provided with multiple locking holes for engaging the locking block. The bottom surface of the slot is provided with two connecting grooves respectively corresponding to the two adjusting rods. The bottom of the two adjusting rods extends through the two connecting grooves to the bottom surface of the lining section and abuts against one end of the corresponding transmission rack.

[0015] As a further improvement to the above solution, torsion springs are sleeved on both ends of the fixed shaft, and one end of the torsion spring is fixed to the inner wall of the slot so as to drive the fixed shaft to automatically return to its original position after rotation.

[0016] As a further improvement to the above solution, the top surface of the pressure plate is provided with a mounting groove for installing the actuating assembly. The actuating assembly includes a rotating shaft rotatably connected in the mounting groove along the width direction of the pressure plate, two linkage gears sleeved on the outer circumference of the rotating shaft, an actuating plate fixed on the outer circumference of the rotating shaft, and fixed racks provided in the mounting groove and respectively meshing with the two linkage gears. One end of each of the two fixed racks is fixedly connected to the top inner wall or bottom inner wall of the slot. The top and bottom surfaces of the insert block are provided with grooves that cooperate with the actuating plate, so that after the actuating plate is inserted into the groove, it drives the insert block to move towards the inside of the slot.

[0017] As a further improvement to the above solution, the outer periphery of the transmission component is provided with a protective cover, and the protective cover is detachably connected to the bottom surface of the lining section.

[0018] As a further improvement to the above solution, the sensor includes a displacement sensor, a strain sensor and an acceleration sensor, the data acquisition frequency is not less than 50Hz, the controller is an industrial-grade PLC controller, and the unlocking response time is no more than 100ms.

[0019] A method for misalignment adaptation control of tunnel lining joints with switchable stiffness includes the following steps:

[0020] S1. Sensors are installed at joints, lining segments and surrounding rock to collect working condition data in real time and transmit it to the controller.

[0021] S2. The controller compares the preset threshold to identify the working conditions and distinguishes between normal use / minor earthquake working conditions and fault large displacement fault working conditions.

[0022] S3. Under normal use / minor earthquake conditions, the control lockable rigid mechanism is locked, and the joint is in a high-rigidity state. Under fault slip conditions, the control lockable rigid mechanism is unlocked, and the joint switches to a flexible state, dissipating energy through deformation.

[0023] S4. After the working condition stabilizes, the lockable rigid mechanism that is far from the slip surface is locked again, the joint is reset to a high-rigidity state, and the lockable rigid mechanism in the lining damage area continues to maintain a flexible state to control the lining damage caused by slippage in a local area.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. By setting a lockable rigid mechanism, the connection space is kept in a normal state during normal use / minor vibration conditions. The two pressure plates press on the top and bottom surfaces of the plug, thereby limiting the swaying of the plug in the connection space and maintaining a high rigidity. However, during fault displacement and faulting conditions, the two pressure plates are driven to move away from each other, the connection space is increased, and the plug has room to move in the slot, thus changing to a flexible connection state to cope with rigid vibrations.

[0026] 2. By setting up an anchoring component, under normal use / minor earthquake conditions, the locking block is used to lock the two adjacent lining sections together in the locking hole, thereby preventing them from separating. At the same time, the setting of the torsion spring also ensures that the locking block will not easily come out of the locking hole without external interference, thus ensuring the stability of the anchoring. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure after the two lining sections are separated;

[0028] Figure 2 This is a schematic diagram of the structure after the two lining sections of the present invention are connected;

[0029] Figure 3 This is a structural diagram of the insert and mounting shaft;

[0030] Figure 4 This is a schematic diagram of the structure of the storage hole;

[0031] Figure 5 This is a schematic diagram of the structure after the lockable rigid mechanism inside the storage hole is connected to the insert block;

[0032] Figure 6 This is a schematic diagram of the drive mechanism on the lining section;

[0033] Figure 7 A schematic diagram of the structure when the connecting plate inside the storage hole is laid flat;

[0034] Figure 8This is a schematic diagram of the structure when the connecting plate inside the storage hole is tilted up.

[0035] Figure 9 This is a schematic diagram showing the connection between the lockable rigid mechanism and the insert block after unlocking.

[0036] Figure 10 for Figure 9 Enlarged view of point A in the middle.

[0037] Explanation of key symbols:

[0038] 1. Lining section; 2. Protective cover; 3. Fixing block; 4. Slot; 5. Pressure plate; 6. Insert block; 7. Groove; 8. Connecting plate; 9. Locking block; 10. Connecting groove; 11. Adjusting rod; 12. Transmission gear; 13. Transmission rack; 14. Telescopic component; 15. Slide groove; 16. Mounting shaft; 17. Limiting groove; 18. Limiting plate; 19. Locking hole; 20. Storage hole; 21. Return spring; 22. Rotating shaft; 23. Fixing rack; 24. Bidirectional screw; 25. Side plate; 26. Mounting groove; 27. Side groove; 28. Fixing shaft; 29. ​​Torsion spring; 30. Actuating plate; 31. Linkage gear; 32. Controller. Detailed Implementation

[0039] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0040] Example 1:

[0041] Please combine Figure 1 - Figure 10 This embodiment of a tunnel lining joint with switchable stiffness includes a lining section 1, sensors installed on the lining section 1, and a controller 32 connected to the sensors and used to distinguish between normal use / minor earthquake conditions and fault large displacement fault conditions. The sensors include displacement sensors, strain sensors, and acceleration sensors, with a data acquisition frequency of not less than 50Hz. Specifically, the displacement sensors are laser displacement sensors with an accuracy of not less than ±0.01mm, and are arranged at both ends of the insert 6 and the inner wall of the slot 4, with 2 to 3 sensors on each side to ensure comprehensive monitoring of the displacement changes of the insert 6. The strain sensors are fiber optic strain sensors, which are attached to the middle and edge of the connecting end face of lining section 1, and the contact surface between pressure plate 5 and insert block 6. Two sensors are installed at each monitoring point to improve data reliability. The accelerometers are piezoelectric accelerometers with a range of 0-50g and a frequency response range of 0.1Hz-10kHz. They are installed in the middle of lining section 1 and at a depth of 1.5-2 times the tunnel diameter in the surrounding rock to ensure accurate vibration data acquisition. The controller 32 is an industrial-grade PLC controller with an unlocking response time of no more than 100ms.

[0042] The two connecting surfaces of the lining section 1 are respectively provided with slots 4 and receiving holes 20. A plug 6 that engages with the slot 4 and a locking element for locking the plug 6 to limit its rotation are installed in the receiving hole 20. The inner walls of both long sides of the receiving hole 20 are provided with sliding grooves 15 arranged along its length. The locking element includes a mounting shaft 16 fixed along the width direction of the plug 6 at one end located inside the receiving hole 20 and a limiting plate 18 fixed on the inner wall of the receiving hole 20 on the side facing its opening. The limiting plate 18 is arranged along the length direction of the mounting shaft 16. The mounting shaft 16 has a limiting groove 17 on its outer periphery for inserting the limiting plate 18. Both ends of the mounting shaft 16 extend into the interior of two sliding grooves 15 and slide in contact with them. A return spring 21 is fixed between the outer periphery of the mounting shaft 16 located in the sliding groove 15 and the inner wall of the sliding groove 15 away from the limiting plate 18. The cooperation between the limiting plate 18 and the limiting groove 17 can effectively limit the rotation of the insertion block 6 and ensure the stability of the connector connection under normal working conditions. The return spring 21 provides a reset force for the insertion block 6, so that the insertion block 6 can return to its initial position after the working conditions are restored.

[0043] The slot 4 is equipped with a lockable rigid mechanism for connecting the plug 6. The lockable rigid mechanism includes two pressure plates 5 disposed inside the slot 4, a drive assembly for adjusting the distance between the two pressure plates 5, and an anchoring assembly for anchoring the receiving hole 20 under normal conditions. The two pressure plates 5 form a connection space for connecting the plug 6. The drive assembly is connected to the controller 32 so that, under the command of the controller 32, it drives the two pressure plates 5 to move away from each other during fault large displacement fault conditions to increase the connection space and form a flexible connection state. Under normal use / minor earthquake conditions, it keeps the size of the connection space unchanged to maintain a high rigidity state. The two long sides of the slot 4 are provided with side grooves 27 arranged along their length. Two sets of drive assemblies are provided and are respectively disposed in the two side grooves 27. The drive assembly includes a bidirectional screw 24 rotatably connected inside the side groove 27 along the height direction of the side groove 27 and two separate threads. Side plates 25 are sleeved on the outside of the bidirectional screw 24. The two side plates 25 are fixed to the sides of the two pressure plates 5 respectively. The bottom of the bidirectional screw 24 extends to the bottom of the lining section 1. The drive assembly also includes a transmission component installed on the bottom surface of the lining section 1 and used to drive the bidirectional screw 24 to rotate. A transmission gear 12 is fixed on the bottom of the bidirectional screw 24 and coaxially arranged therewith. The transmission component includes a telescopic component 14 installed on the bottom surface of the lining section 1 and a transmission rack 13 fixed on the extended section of the telescopic component 14. The transmission rack 13 meshes with the transmission gear 12. The telescopic component 14 adopts one of electric push rod or hydraulic telescopic rod. Through telescopic movement, it drives the transmission rack 13 to move, thereby driving the transmission gear 12 and the bidirectional screw 24 to rotate, realizing efficient power transmission. After the two pressure plates 5 move away from each other, the connection space becomes larger, and the movement space of the insert 6 in the slot 4 becomes larger, which can adapt to the fault large displacement and misalignment conditions.

[0044] The anchoring assembly cooperates with the drive assembly to release the anchoring of the receiving hole 20 when the connection space is increased. The anchoring assembly includes a fixed shaft 28 rotatably connected inside the slot 4 along the width direction, multiple connecting plates 8 fixed to the outer periphery of the fixed shaft 28 in the radial direction, and two adjusting rods 11. The end of the connecting plate 8 away from the fixed shaft 28 extends to the outside of the slot 4, and a locking block 9 is fixed on the bottom surface of the connecting plate 8 at the outer end of the slot 4. The bottom surface of the receiving hole 20 has multiple locking holes 19 for engaging the locking blocks 9. The bottom surface of the slot 4 has two connecting grooves 10 respectively corresponding to the two adjusting rods 11. The bottom of the two adjusting rods 11 extends through the two connecting grooves 10 to the bottom surface of the lining section 1 and connects with the corresponding transmission teeth. When one end of the rack 13 is in contact with the other end, under normal working conditions, the locking block 9 is inserted into the locking hole 19 to anchor the two lining sections 1. When connecting the two lining sections 1, the adjusting rod 11 can be moved to the side away from the transmission rack 13, thereby causing the connecting plate 8 to tilt upwards, preventing the locking block 9 from getting stuck on the outer edge of the receiving hole 20, so that the connecting plate 8 and the locking block 9 can be smoothly inserted into the receiving hole 20. After the two lining sections 1 are connected, the adjusting rod 11 is rotated downwards to make the locking block 9 lock into the locking hole 19, thereby completing the anchoring. When the transmission rack 13 moves, it will push the adjusting rod 11 to move upwards, thereby causing the connecting plate 8 to rotate around the fixed shaft 28, causing the locking block 9 to disengage from the locking hole 19, releasing the anchoring, and realizing the linkage control between the anchoring state and the unlocking state.

[0045] Furthermore, torsion springs 29 are sleeved on both ends of the fixed shaft 28. One end of the torsion spring 29 is fixed to the inner wall of the slot 4 so as to drive the fixed shaft 28 to automatically return to its original position after rotation. The torsion spring 29 provides the reset torque for the fixed shaft 28. When the working condition returns to stability and the transmission rack 13 is reset, the torsion spring 29 can drive the connecting plate 8 to return to the initial position, so that the locking block 9 can be re-engaged into the locking hole 19, realizing the automatic restoration of the anchoring state and improving the self-resetting capability of the joint.

[0046] The pressure plate 5 is equipped with a toggle assembly for moving the insert 6 into the slot 4 when the connection space is increased during the operation of the drive assembly. The toggle assembly cooperates with a locking assembly to release the locking member's restriction on the insert 6 when the connection space is increased, and cooperates with a lockable rigid mechanism to change to a flexible connection state. The top surface of the pressure plate 5 has a mounting groove 26 for mounting the toggle assembly. The toggle assembly includes a rotating shaft 22 rotatably connected to the mounting groove 26 along the width direction of the pressure plate 5, two linkage gears 31 sleeved on the outer periphery of the rotating shaft 22, a toggle plate 30 fixed on the outer periphery of the rotating shaft 22, and fixed racks 23 disposed in the mounting groove 26 and meshing with the two linkage gears 31 respectively. One end is fixed to the top or bottom inner wall of the slot 4. The top and bottom surfaces of the insert 6 are provided with grooves 7 that cooperate with the actuating plate 30. After the actuating plate 30 is engaged in the groove 7, it drives the insert 6 to move towards the inside of the slot 4. When the pressure plate 5 moves, since the fixed rack 23 is fixed, the linkage gear 31 will roll relative to the fixed rack 23, thereby driving the rotating shaft 22 and the actuating plate 30 to rotate. After the actuating plate 30 is engaged in the groove 7, it pushes the insert 6 to move. At the same time, the movement of the insert 6 will cause the limiting groove 17 to disengage from the limiting plate 18, releasing the locking member from restricting the rotation of the insert 6, so that the insert 6 can move flexibly in the connection space. With the help of the lockable rigid mechanism, the switching of the flexible connection state can be realized.

[0047] The implementation principle of this embodiment is as follows: Under normal use / minor earthquake conditions, the controller 32 controls the telescopic component 14 to remain in a retracted state, the bidirectional screw 24 is stationary, the two pressure plates 5 clamp the insert 6, the connection space maintains its initial size, and the locking block 9 is inserted into the locking hole 19 to achieve anchoring. The limiting plate 18 is inserted into the limiting groove 17 to restrict the rotation of the insert 6, and the joint is in a high-rigidity state. When encountering a fault with large displacement, if the displacement, strain, or acceleration data collected by the sensor exceeds the preset threshold, the controller 32 immediately controls the telescopic component 14 to extend, driving the transmission rack 13 to move, thereby driving the bidirectional screw 24 to rotate, so that the pressure plates 5 move away from each other and the connection space is increased. During the movement of the transmission rack 13... Pushing the adjusting rod 11 upwards causes the locking block 9 to disengage from the locking hole 19 and release its anchorage. Simultaneously, the pressure plate 5 moves, causing the linkage gear 31 to roll relative to the fixed rack 23, driving the actuating plate 30 to rotate. After one end of the actuating plate 30 enters the groove 7 and abuts against the edge of the groove 7, it begins to push the insert 6 into the slot 4, thereby causing the limiting groove 17 to disengage from the limiting plate 18, releasing the rotation restriction of the insert 6, and the joint switches to a flexible state. Energy is dissipated through the movement, rotation, and deformation of the components of the insert 6. After the working condition returns to stability, the controller 32 controls the telescopic component 14 to retract and reset. Under the action of the torsion spring 29 and the reset spring 21, each component returns to its initial position, and the joint resets to a high-rigidity state.

[0048] Example 2:

[0049] Combination Figure 5 - Figure 10 Based on Embodiment 1, this embodiment is further improved in that: a protective cover 2 is provided on the outer periphery of the transmission component, and the protective cover 2 is detachably connected to the bottom surface of the lining section 1. Multiple fixing blocks 3 are fixed on the outer side of the protective cover 2, and fixing bolts are threaded on the fixing blocks 3. Bolt holes for connecting the fixing bolts are opened on the bottom surface of the lining section 1. The protective cover 2 can be easily disassembled and assembled by the cooperation of the fixing bolts and the bolt holes. The setting of the protective cover 2 effectively protects the transmission component and the adjusting rod 11, preventing them from being disturbed by external forces or dust, and also preventing dust from entering the slot 4 from the connecting groove 10.

[0050] Example 3:

[0051] Combination Figure 1 - Figure 10 This embodiment, based on Embodiments 1 and 2, further improves upon the following: a method for controlling the misalignment of a tunnel lining joint with switchable stiffness, comprising the following steps:

[0052] S1. Sensors are installed at joints, lining segments, and surrounding rock to collect working condition data in real time and transmit it to the controller. The sensors are installed according to the preset layout scheme. Displacement sensors are installed on the contact surface between the insert 6 and the slot 4, and on the connecting end face of the lining segment 1. Strain sensors are attached to the key stress parts of the lining segment 1 and the surfaces of core components such as the pressure plate 5 and the insert 6. Acceleration sensors are installed in the stable areas of the lining segment 1 and the surrounding rock. The data output terminals of all sensors are electrically connected to the signal input terminals of the controller 32 to realize the real-time acquisition and transmission of working condition data.

[0053] S2. The controller compares preset thresholds to identify the operating conditions, distinguishing between normal use / minor earthquake conditions and fault large displacement fault conditions. The controller 32 has pre-stored displacement thresholds, strain thresholds, and acceleration thresholds. These thresholds are determined through extensive experimental data and numerical simulation analysis, enabling accurate differentiation of different operating condition types. After receiving data transmitted from the sensors, the controller 32 compares the real-time collected displacement, strain, and acceleration values ​​with the corresponding preset thresholds. When all real-time data are less than or equal to the preset thresholds, it is determined to be a normal use / minor earthquake condition. When any real-time data exceeds the preset threshold, it is determined to be a fault large displacement fault condition, and subsequent control commands are immediately triggered.

[0054] S3. Under normal use / minor earthquake conditions, the lockable rigid mechanism is locked, and the joint is in a high-rigidity state. Under fault displacement conditions, the lockable rigid mechanism is unlocked, and the joint switches to a flexible state, dissipating energy through deformation. Under normal use / minor earthquake conditions, the controller 32 controls the telescopic component 14 to remain in a retracted state, the transmission rack 13 does not move, the bidirectional screw 24 remains stationary, the two pressure plates 5 are in a close proximity state, the connection space maintains its initial size, the insert 6 is clamped and fixed by the pressure plate 5, and at the same time, the locking block 9 of the anchoring component is inserted into the locking hole 19, and the limiting plate 18 of the locking component is inserted into the limiting groove 17. All components of the joint work together to form a high-rigidity connection state, ensuring the integrity and load-bearing capacity of the tunnel structure. When a fault displacement condition is determined, the controller 32 immediately sends an extension command to the telescopic component 14. The shrinking component 14 drives the transmission rack 13 to move, which in turn drives the transmission gear 12 and the bidirectional screw 24 to rotate, causing the two side plates 25 to move away from the pressure plate 5, thus increasing the connection space. At the same time, the transmission rack 13 pushes the adjusting rod 11 to move upward, causing the connecting plate 8 to rotate, and the locking block 9 to disengage from the locking hole 19, releasing the anchor. During the movement of the pressure plate 5, the linkage gear 31 rolls relative to the fixed rack 23, driving the rotating shaft 22 and the actuating plate 30 to rotate. The actuating plate 30 engages with the groove 7 and pushes the insert 6 to move inward toward the slot 4, causing the limiting groove 17 to disengage from the limiting plate 18, releasing the rotation restriction of the insert 6. At this time, the insert 6 can move and rotate freely in the connection space, and the joint switches to a flexible state. The energy generated by earthquakes or fault displacement is dissipated through the movement and rotation of the insert 6 and the deformation of related components, reducing the impact force on the structure.

[0055] S4. After the working condition stabilizes, the lockable rigid mechanism far from the misalignment surface is locked again, and the joint is reset to a high-rigidity state. The lockable rigid mechanism in the lining damage area continues to maintain a flexible state to control the lining damage caused by misalignment within a local area. The controller 32 continuously monitors the data collected by the sensors. When all real-time data recovers to below the preset threshold and remains stable for a period of time (e.g., 3-5 seconds), the working condition is determined to have stabilized. The controller 32 sends a retraction command to the telescopic component 14. The telescopic component 14 drives the transmission rack 13 to move in the opposite direction, the bidirectional screw 24 rotates in the opposite direction, and the pressure plates 5 move closer to each other and return to their initial positions. The connection space is restored to its initial size; at the same time, the torsion spring 29 drives the connecting plate 8 to reset, the locking block 9 re-engages into the locking hole 19, and the anchoring state is restored; the reset spring 21 pushes the mounting shaft 16 to drive the insertion block 6 to reset, the limiting plate 18 re-inserts into the limiting groove 17, the locking component is restored to the locked state, and the toggle assembly also returns to its initial position during the reset of the pressure plate 5. The joint as a whole is reset to a high-rigidity state, ensuring that the tunnel structure restores its normal load-bearing capacity. In the area of ​​lining misalignment and damage, it continues to maintain a flexible state, controlling the lining damage caused by misalignment to a local area, protecting the lining in other areas from overall damage, and then carrying out repairs.

[0056] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A tunnel lining joint with switchable stiffness, comprising a lining section (1), a sensor installed on the lining section (1), and a controller (32) connected to the sensor and used to distinguish between normal use / minor earthquake conditions and fault large displacement fault conditions, characterized in that, The two sides of the lining section (1) are respectively provided with slots (4) and storage holes (20). The storage holes (20) are equipped with plugs (6) that are inserted into the slots (4) and locking members for locking the plugs (6) to limit their rotation. The slots (4) are equipped with lockable rigid mechanisms for connecting the plugs (6). The lockable rigid mechanism includes two pressure plates (5) disposed inside the slot (4), a drive assembly for adjusting the distance between the two pressure plates (5), and an anchoring assembly for anchoring the receiving hole (20) under normal conditions. The two pressure plates (5) form a connection space for connecting the plug (6). The drive assembly is connected to the controller so that, under the command of the controller (32), the two pressure plates (5) are driven to move away from each other during fault large displacement faulting conditions to increase the connection space and form a flexible connection state. During normal use / small earthquake conditions, the size of the connection space remains unchanged to maintain a high rigidity state. The anchoring component cooperates with the driving component to release the anchoring of the receiving hole (20) when the connection space is increased; The pressure plate (5) is equipped with a toggle component for moving the plug (6) into the slot (4) when the drive assembly is operating to increase the connection space. The toggle component cooperates with the locking component to release the locking member from the plug (6) when the connection space is increased, and cooperates with the lockable rigid mechanism to change to a flexible connection state.

2. The tunnel lining joint with switchable stiffness according to claim 1, characterized in that, The inner walls of both sides of the storage hole (20) are provided with sliding grooves (15) arranged along their length direction. The locking component includes a mounting shaft (16) fixed along the width direction of the insert (6) at one end located inside the storage hole (20) and a limiting plate (18) fixed on the inner wall of the storage hole (20) facing the opening. The limiting plate 18 is arranged along the length direction of the mounting shaft (16). The outer periphery of the mounting shaft (16) is provided with a limiting groove (17) for inserting the limiting plate (18). The two ends of the mounting shaft (16) extend into the two sliding grooves (15) and slide with them. A return spring (21) is fixed between the outer periphery of the mounting shaft (16) located inside the sliding groove (15) and the inner wall of the sliding groove (15) away from the limiting plate (18).

3. A tunnel lining joint with switchable stiffness according to claim 1, characterized in that, The slot (4) has side grooves (27) on both long sides along its length. The drive assembly has two sets and is respectively located in the two side grooves (27). The drive assembly includes a bidirectional screw (24) rotatably connected inside the side groove (27) along its height direction and two side plates (25) threaded onto the outside of the bidirectional screw (24). The two side plates (25) are respectively fixed to the sides of the two pressure plates (5). The bottom of the bidirectional screw (24) extends to the bottom of the lining section (1). The drive assembly also includes a transmission component installed on the bottom surface of the lining section (1) for driving the bidirectional screw (24) to rotate.

4. A tunnel lining joint with switchable stiffness according to claim 3, characterized in that, The bottom of the bidirectional screw (24) is fixed with a transmission gear (12) coaxially arranged therewith. The transmission component includes a telescopic component (14) installed on the bottom surface of the lining section (1) and a transmission rack (13) fixed on the extended section of the telescopic component (14). The transmission rack (13) meshes with the transmission gear (12).

5. A tunnel lining joint with switchable stiffness according to claim 4, characterized in that, The anchoring assembly includes a fixed shaft (28) rotatably connected inside the slot (4) in the width direction, multiple connecting plates (8) fixed to its outer periphery in the radial direction of the fixed shaft (28), and two adjusting rods (11). One end of the connecting plate (8) away from the fixed shaft (28) extends to the outside of the slot (4), and a locking block (9) is fixed on the bottom surface of the connecting plate (8) at the outside end of the slot (4). The bottom surface of the receiving hole (20) is provided with multiple locking holes (19) for engaging the locking block (9). The bottom surface of the slot (4) is provided with two connecting grooves (10) respectively corresponding to the two adjusting rods (11). The bottom of the two adjusting rods (11) extends through the two connecting grooves (10) to the bottom surface of the lining section (1) and abuts against one end of the corresponding transmission rack (13).

6. A tunnel lining joint with switchable stiffness according to claim 5, characterized in that, Both ends of the fixed shaft (28) are fitted with torsion springs (29). One end of the torsion spring (29) is fixed to the inner wall of the slot (4) so ​​that it can be driven to automatically return to its original position after the fixed shaft (28) rotates.

7. A tunnel lining joint with switchable stiffness according to claim 1, characterized in that, The top surface of the pressure plate (5) is provided with a mounting groove (26) for installing the actuating component. The actuating component includes a rotating shaft (22) rotatably connected in the mounting groove (26) along the width direction of the pressure plate (5), two linkage gears (31) sleeved on the outer periphery of the rotating shaft (22), an actuating plate (30) fixed on the outer periphery of the rotating shaft (22), and fixed racks (23) provided in the mounting groove (26) and meshing with the two linkage gears (31) respectively. One end of each of the two fixed racks (23) is fixedly connected to the top inner wall or bottom inner wall of the slot (4). The top and bottom surfaces of the insert (6) are provided with grooves (7) that cooperate with the actuating plate (30) so that the insert (6) can be driven to move towards the inside of the slot (4) after the actuating plate (30) is inserted into the groove (7).

8. A tunnel lining joint with switchable stiffness according to claim 4, characterized in that, The outer periphery of the transmission component is provided with a protective cover (2), and the protective cover (2) is detachably connected to the bottom surface of the lining section (1).

9. A tunnel lining joint with switchable stiffness according to claim 1, characterized in that, The sensors include displacement sensors, strain sensors and acceleration sensors, with a data acquisition frequency of not less than 50Hz. The controller (32) is an industrial-grade PLC controller with an unlocking response time of not more than 100ms.

10. A method for controlling the misalignment of a tunnel lining joint with switchable stiffness according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Sensors are installed at joints, lining segments and surrounding rock to collect working condition data in real time and transmit it to the controller. S2. The controller compares the preset threshold to identify the working conditions and distinguishes between normal use / minor earthquake working conditions and fault large displacement fault working conditions. S3. Under normal use / minor earthquake conditions, the control lockable rigid mechanism is locked, and the joint is in a high-rigidity state. Under fault slip conditions, the control lockable rigid mechanism is unlocked, and the joint switches to a flexible state, dissipating energy through deformation. S4. After the working condition stabilizes, the lockable rigid mechanism that is far from the slip surface is locked again, the joint is reset to a high-rigidity state, and the lockable rigid mechanism in the lining damage area continues to maintain a flexible state to control the lining damage caused by slippage in a local area.

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