Post-earthquake tunnel treatment method and repair structure

Abstract

This invention provides a post-earthquake tunnel repair method and repair structure that improves the shear bearing capacity and seismic toughness of the repair structure under continuous creep in active fault zones and subsequent earthquakes through a multi-stage shear-yield structure. This addresses the technical problems of existing repair structures lacking multi-stage shear-yield functionality and having insufficient adaptability to subsequent earthquakes, and relates to the field of tunnel repair technology. The post-earthquake tunnel repair structure includes a waterproof layer disposed inside the tunnel and a lining structure disposed inside the waterproof layer. The lining structure includes multiple lining segments arranged sequentially along the circumference of the tunnel; any two adjacent lining segments are connected by a multi-stage shear-yield structure. The multi-stage shear-yield structure includes prestressed steel bars, a first steel plate, a second steel plate, grooves, bosses, radial misalignment gaps, circumferential clearance gaps, and a first force-transmitting pad. This invention improves the structural safety and long-term service performance of tunnels under complex geological conditions.

Description

Technical Field

[0001] This invention relates to the field of tunnel repair technology, specifically a method for post-earthquake tunnel treatment and repair structure. Background Technology

[0002] Following intense tectonic movements, new tectonic fracture zones often form, which may penetrate existing operational tunnels. These fracture zones cause stress redistribution in the surrounding rock on which the tunnel depends, making it difficult for the original tunnel lining reinforcement design to meet the stress requirements. This leads to widespread cracking and water leakage in the lining. If not addressed promptly, the surrounding rock on both sides of the external fracture zone will further slide, causing the stress on the lining structure to continue to deteriorate, potentially leading to structural collapse due to insufficient bearing capacity.

[0003] There are already some relevant technical solutions for the treatment and repair of tunnel earthquake damage.

[0004] Chinese patent CN115059484B discloses a method for repairing tunnel structures after an earthquake. By setting up a circumferential steel arch and replacing the vertical temporary support in sections, it is beneficial to lay the waterproof layer in sections, ensuring the waterproof effect of the tunnel invert arch. Furthermore, by reinforcing the damaged strata around the tunnel with grouting, the method enables the replacement and repair of the damaged structure.

[0005] Chinese patent CN222162646U proposes a post-earthquake arch repair structure for a traffic tunnel, including a steel frame arch and a seismic isolation component. The steel frame arch is set below the tunnel lining section, and the seismic isolation component is set on the inner surface of the initial support of the repaired arch. The steel frame arch is used for temporary reinforcement to improve the stability of the upper structure of the lining, and the seismic isolation component reduces the uneven deformation of the surrounding rock and structure caused by vibration.

[0006] Chinese patent application CN119288533A discloses a tunnel post-earthquake repair system and method, including a waterproof membrane, a lining ring, a rebar gauge, a concrete strain gauge, and a laser displacement gauge. The rebar gauge is used to measure the force on the lining ring, the concrete strain gauge is used to detect the strain inside the lining ring, and the laser displacement gauge is used to measure the opening and closing degree of the lining ring to monitor the deformation, displacement, settlement, strain, and slippage of the tunnel.

[0007] However, the aforementioned existing technologies still have the following shortcomings: (i) Lack of multi-level shear yielding function in repair structures. When a strong earthquake triggers interrock slip in a tectonic fracture zone, the lining structure is subjected to significant shear forces. Existing repair structures often use monolithic rigid linings, which cannot effectively dissipate energy under shear stress and are prone to brittle failure at shear concentration points. While some technologies employ segmental design, the connection structures between lining blocks lack consideration for a multi-level protection mechanism of "shear yielding under small deformations and shear resistance under large deformations," making it difficult to adapt to the complex stress conditions of continuous creep in active fault zones.

[0008] (ii) Insufficient adaptability to subsequent earthquakes. Existing repair technologies mostly focus on restoring the structural function after an earthquake, and the repaired tunnel structure continues to operate according to the original seismic fortification standards. For aftershocks and future earthquakes that may occur in active fault zones, existing repaired structures lack effective coping mechanisms—they cannot dissipate seismic energy through structural deformation, nor can they maintain structural stability under multiple earthquakes, making the repaired structures susceptible to further damage in subsequent earthquakes and unable to achieve safe operation over a long lifespan.

[0009] For the reasons mentioned above, it is necessary to conduct a systematic study and design of post-earthquake tunnel structure repair structures, focusing on solving the technical problems of existing repair structures lacking multi-level shear yielding function and insufficient adaptability to subsequent earthquakes, so that the repair structures have the adaptive protection capability of "small deformation shear yielding energy dissipation and large deformation shear resistance limiting" under the complex stress conditions of active fault zones. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a post-earthquake tunnel treatment method and repair structure that improves the shear bearing capacity and seismic toughness of the repair structure under continuous creep in active fault zones and subsequent earthquakes through a multi-stage shear yielding structure, so as to solve the technical problems of existing repair structures lacking multi-stage shear yielding function and insufficient adaptability to subsequent earthquakes.

[0011] The technical solution adopted by this invention to solve its technical problem is: a post-earthquake tunnel treatment method, comprising the following steps: S1. Use ground-penetrating radar to determine the three-dimensional distribution of the structural fracture zone behind the tunnel crack, and determine the treatment area based on the determined three-dimensional distribution of the structural fracture zone. S2. Based on the determined three-dimensional distribution of the structural fracture zone, grouting anchors are driven into the structural fracture zone from the original tunnel lining, and grouting is performed. S3. Remove the original tunnel lining within the treatment area and lay a waterproof layer; S4. Construct a new lining structure inside the waterproof layer. The lining structure includes multiple lining segments arranged sequentially along the circumference of the tunnel. Any two adjacent lining segments are connected by a multi-stage shear structure. The multi-stage shear structure includes prestressed steel bars, a first steel plate, a second steel plate, a groove, a boss, a radial misalignment gap, a circumferential clearance gap, and a first force transmission pad; wherein, the groove is disposed on one end face of two adjacent lining sections, the boss is disposed on the other end face, and the boss is inserted into the groove; the first steel plate is disposed on the end face of the boss, and the second steel plate is disposed on the bottom surface of the groove; both the first steel plate and the second steel plate have a serrated structure on their opposing surfaces, and a serrated structure is provided between the first steel plate and the second steel plate. The first force-transmitting liner; one end of the prestressed steel bar is connected to one of the two adjacent lining sections, and the other end is connected to the other section, so that the first steel plate and the second steel plate abut against each other through the first force-transmitting liner; a gap is provided between the outer side of the boss and the outer side wall of the groove to form the radial misalignment gap, and a compressible elastic pad is provided in the radial misalignment gap; a gap is provided between the opposing end faces of the two adjacent lining sections to form the circumferential clearance gap; the width of the circumferential clearance gap is greater than the distance between the first steel plate and the second steel plate.

[0012] Furthermore, the distance between the first steel plate and the second steel plate is d. ;in: This represents the maximum radial displacement that the lining section corresponding to the second steel plate can produce. : Radial misalignment clearance; D: Minimum thickness of the elastic pad after compression; The central angle is the lining section corresponding to the second steel plate.

[0013] Furthermore, one end of the lining section is provided with the boss, and the other end is provided with the groove.

[0014] Furthermore, a second force-transmitting pad is provided between the inner side of the boss and the inner sidewall of the groove.

[0015] Furthermore, a compressible water-stop block is provided within the circumferential clearance.

[0016] Furthermore, the waterproof layer is provided with a U-shaped structure at the joint of the lining section.

[0017] The post-earthquake tunnel repair structure includes a waterproof layer installed inside the tunnel and a lining structure installed inside the waterproof layer. The lining structure includes multiple lining segments arranged sequentially along the circumference of the tunnel. Any two adjacent lining segments are connected by a multi-stage shear structure. The multi-stage shear structure includes prestressed steel bars, a first steel plate, a second steel plate, a groove, a boss, a radial misalignment gap, a circumferential clearance gap, and a first force-transmitting pad; wherein, the groove is disposed on one end face of two adjacent lining sections, the boss is disposed on the other end face, and the boss is inserted into the groove; the first steel plate is disposed on the end face of the boss, and the second steel plate is disposed on the bottom surface of the groove; both the first steel plate and the second steel plate have a serrated structure on their opposing surfaces, and there is a toothed structure between the first steel plate and the second steel plate. The first force-transmitting pad is provided; one end of the prestressed steel bar is connected to one of the two adjacent lining sections, and the other end is connected to the other section, so that the first steel plate and the second steel plate abut against each other through the first force-transmitting pad; a gap is provided between the outer side of the boss and the outer side wall of the groove to form the radial misalignment gap, and a compressible elastic pad is provided in the radial misalignment gap; a gap is provided between the opposing end faces of the two adjacent lining sections to form the circumferential clearance gap; the width of the circumferential clearance gap is greater than the thickness of the first force-transmitting pad.

[0018] Furthermore, the thickness of the first force-transmitting pad is d. ;in: This represents the maximum radial displacement that can occur in the lining section corresponding to the second steel plate. The central angle of the lining section corresponding to the second steel plate; : Radial misalignment clearance; D: Minimum thickness of the elastic pad after compression.

[0019] Furthermore, one end of the lining section is provided with the boss, and the other end is provided with the groove.

[0020] Furthermore, a compressible water-stop block is provided within the circumferential clearance.

[0021] The beneficial effects of this invention are as follows: The post-earthquake tunnel treatment method and repair structure of this invention, through the multi-segmentation of the lining structure and the multi-level shear yielding structure, realizes a four-fold protection mechanism of energy dissipation under small deformation shear yielding and shear limiting under large deformation. This significantly improves the shear bearing capacity and seismic toughness of the repair structure under continuous creep of active fault zones and subsequent earthquake action. It effectively solves the technical problems of existing repair structures lacking multi-level shear yielding function and insufficient adaptability to subsequent earthquakes, and improves the structural safety and long-term service performance of tunnels under complex geological conditions. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the post-earthquake tunnel repair structure of the present invention; Figure 2 This is a schematic diagram of the multi-stage shear structure of the present invention; The diagram shows: Tunnel 1, structural fracture zone 2, grouting anchor 3, waterproof layer 4, lining structure 6, lining section 61, boss 71, groove 72, first steel plate 73, second steel plate 74, first force transmission pad 75, prestressed steel bar 76, radial misalignment gap 77, elastic pad 78, circumferential clearance gap 79, second force transmission pad 80, and waterstop block 81. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] like Figure 1 , Figure 2 As shown, a post-earthquake tunnel treatment method of the present invention includes the following steps: S1. The three-dimensional distribution of the structural fracture zone 2 behind the crack in tunnel 1 was determined using ground-penetrating radar, and the treatment area was determined based on the determined three-dimensional distribution of the structural fracture zone 2. S2. Based on the determined three-dimensional distribution of the structural fracture zone 2, grouting anchors 3 are driven into the structural fracture zone 2 from the original tunnel lining, and grouting is performed. S3. Remove the original tunnel lining within the treatment area and lay a waterproof layer 4; the waterproof layer 4 can be made of waterproof membrane, flexible waterproof material, etc. S4. Construct a new lining structure 6 inside the waterproof layer 4. The lining structure 6 includes multiple lining sections 61 arranged sequentially along the circumference of the tunnel. Any two adjacent lining sections 61 are connected by a multi-stage shear structure. The multi-stage shear structure includes prestressed steel bars 76, a first steel plate 73, a second steel plate 74, a groove 72, a boss 71, a radial misalignment gap 77, a circumferential clearance gap 79, and a first force transmission pad 75; wherein, the groove 72 is provided on one end face of two adjacent lining sections 61, the boss 71 is provided on the other end face, and the boss 71 is inserted into the groove 72; the first steel plate 73 is provided on the end face of the boss 71, and the second steel plate 74 is provided on the bottom surface of the groove 72; both the facing surfaces of the first steel plate 73 and the second steel plate 74 are provided with a serrated structure, and the first force transmission pad 75 is provided between the first steel plate 73 and the second steel plate 74; the prestressed steel bars 76, the first steel plate 73, the second steel plate 74, the first steel plate 74, the second steel plate 74, the first steel plate 75, the first steel plate 74, the second steel plate 74, the first steel plate 75, the first steel plate 76, the second steel plate 74, the first steel plate 76, the second steel plate 74, the third steel plate 76, the fourth steel plate 76, the fifth steel plate 76, the sixth steel plate 76, the seventh steel plate 76, the fifth steel plate 76, the sixth steel plate 76, the seventh steel plate 76, the fifth steel plate 76, the sixth steel plate 76, the seventh steel plate 76, the eighth steel plate 76, the ninth steel plate 76, the tenth ... One end of the reinforcing bar 76 is connected to one of the two adjacent lining sections 61, and the other end is connected to the other section, so that the first steel plate 73 and the second steel plate 74 abut against each other through the first force-transmitting pad 75, thereby maintaining the structural stability of the adjacent lining sections and resisting the normal expansion force of the surrounding rock; a gap is provided between the outer side of the boss 71 and the outer side wall (the side plate away from the tunnel center) of the groove 72 to form the radial misalignment gap 77, and a compressible elastic pad 78 is provided in the radial misalignment gap 77; a gap is provided between the opposing end faces of the two adjacent lining sections 61 to form the circumferential clearance gap 79; the width of the circumferential clearance gap 79 is greater than the distance between the first steel plate 73 and the second steel plate 74.

[0025] The treatment area is determined based on the identified three-dimensional distribution of the structural fracture zone 2. Specifically, the projected area of ​​the structural fracture zone 2 on the tunnel lining is determined based on its three-dimensional distribution, and then the treatment area is determined accordingly. Generally, the treatment area must at least cover the projected area.

[0026] The width of the circumferential clearance 79 is greater than the distance between the first steel plate 73 and the second steel plate 74, so that the two adjacent lining sections have enough displacement space in the circumferential direction of the tunnel, so that the first steel plate 73 and the second steel plate 74 can approach each other and enter a sawtooth meshing state during the misalignment process.

[0027] In this invention, the number and location of segments in the newly constructed lining structure are typically determined based on its stress conditions. Specifically, this can be achieved by modeling and analyzing parameters such as tunnel surrounding rock conditions and lining thickness using finite element analysis software to obtain the shear force distribution pattern of the new lining structure. Segments are then placed in areas with high shear force to fully utilize the shear resistance of the multi-stage shear-yielding structure. The number of segments is determined based on the principle that the shear force in the peak shear force region is effectively reduced and the overall stress on the lining structure tends to be uniform; the specific values ​​are determined by the actual stress analysis results of the project. The lining segments are typically constructed of reinforced concrete.

[0028] This invention addresses the issue from two dimensions: root cause treatment of geological structures and multi-level shear tolerance of the lining structure. First, it uses ground-penetrating radar to accurately detect the three-dimensional distribution of the structural fracture zone and determine the treatment area. Then, grouting anchors 3 are driven into the fracture zone and grout is injected to systematically reinforce the loose surrounding rock, fundamentally curbing the continuous creep and sliding of the structural fracture zone 2 and eliminating the harmful effects of the surrounding rock on the lining structure. Based on this, the original lining within the treatment area is removed and a waterproof layer is laid. A new lining structure consisting of multiple lining segments is constructed on the inner side. Adjacent lining segments are connected by grooves and bosses, interlocking sawtooth steel plates and the first force-transmitting pad 75, elastic pad compression buffering, and rigid limiting of the bosses and groove sidewalls. The method forms a four-fold shear yielding mechanism, with circumferential yielding gaps between the opposing end faces of the lining sections to provide space for lining misalignment. This allows each shear defense line to be activated step by step in a predetermined sequence, thereby achieving adaptive protection of shear energy release during small deformations and shear restraint during large deformations. This significantly improves the shear bearing capacity and seismic toughness of the repaired structure under continuous creep in active fault zones and aftershocks. At the same time, this method integrates deep grouting reinforcement, permanent lining support, multi-level energy dissipation, and waterproof protection into one, eradicating the problem of water leakage in the lining. This enables the repaired structure to continuously cope with subsequent earthquakes, effectively solving the technical problems of existing repair structures lacking multi-level shear yielding function and insufficient adaptability to subsequent earthquakes.

[0029] Specifically, the working principle of the step-by-step shearing mechanism of the present invention is as follows: First-stage shear yielding (elastic adaptation stage): When slight creep or minor earthquakes cause rock displacement in the active fault zone, the newly constructed lining structure is composed of multiple segments connected by grooves 72 and protrusions 71. A radial displacement gap 77 is reserved between the outer side of the protrusion and the outer wall of the groove, and a circumferential yielding gap 79 is reserved between the end faces of the lining segments. This allows for relative displacement along the tunnel radially between adjacent lining segments 61 (during radial displacement, circumferential displacement occurs due to radius changes). In the initial stage of displacement (when the displacement is small), the shear force is jointly borne by the prestressed steel bar 76, the elastic resistance of the elastic pad 78, and the frictional resistance of the first force-transmitting lining pad 75. The prestressed steel bar 76 absorbs some shear energy through elastic tensile deformation, and the elastic pad 78 absorbs some shear energy through deformation. Simultaneously, the lining segments release shear energy through frictional slippage between the first steel plate 73 and the second steel plate 74. This stage primarily involves yielding, allowing small displacement of the lining segments to release shear stress and avoid stress concentration.

[0030] Second-stage shear yielding (serrated engagement stage): When the displacement continues to increase and exceeds the bearing capacity of the first-stage shear yielding, the serrated structures on the first steel plate 73 and the second steel plate 74 gradually enter a meshing state during the displacement process, and the engagement depth gradually increases with the increase of radial displacement. At this time, the shear force is gradually transmitted from one side of the lining section through the first steel plate 73 on the boss, the first force transmission pad 75, and the second steel plate 74 on the bottom of the groove to the other side of the lining section. The force transmission path changes from "friction slip" to a composite mode of "friction slip + serrated engagement force transmission". In this stage, through the further elastic tension of the prestressed steel bar 76, the compressive deformation of the first force transmission pad 75, and the gradual engagement of the serrated steel plates, the structure allows the lining section to generate a certain relative displacement to release shear stress, while dissipating a large amount of shear energy by utilizing the material's own damping characteristics and the plastic deformation between the serrated interfaces, thus significantly improving the shear stiffness.

[0031] The third stage of shear resistance (elastic pad compression and resistance limiting stage): When the displacement further increases to the point where the elastic pad 78 is compressed to near its limit, the radial displacement gap 77 between the outer side of the boss 71 and the outer side wall of the groove 72 gradually tends to close. The compressive resistance of the elastic pad 78 increases sharply, and at the same time, the engagement depth of the serrated steel plate reaches its maximum value. The sliding resistance of the first steel plate 73 and the second steel plate 74 along the radial direction of the tunnel is greatly increased. In this stage, the structure is mainly "resistive," providing high resistance shear capacity through the ultimate compressive resistance of the elastic pad and the full engagement state of the serrated structure to prevent the displacement from developing too quickly.

[0032] Fourth-stage shear (rigid limiting stage): When the radial displacement reaches the preset limit value (i.e., the elastic pad 78 is compressed to the minimum thickness D and cannot be compressed further), the outer side of the boss 71 directly contacts the outer side wall of the groove 72. The high rigidity of the boss and the side wall of the groove itself forms a rigid mechanical limit on the displacement, preventing the displacement from developing further, preventing the lining section from detaching or becoming unstable due to excessive displacement, and ensuring that the structure does not collapse as a whole under extreme working conditions.

[0033] In summary, the four lines of defense are activated in the following order: "elastic shear yield (level 1) → sawtooth progressive engagement shear yield (level 2) → elastic pad compression resistance (level 3) → rigid limiting shear resistance (level 4)". This achieves an adaptive protection function of "small deformation shear energy dissipation and large deformation shear resistance limiting". Under normal creep and minor earthquakes, the shear energy dissipation protects the lining structure from shear damage. Under strong earthquakes and extreme displacements, the rigid limiting prevents the structure from losing overall stability. This significantly improves the shear bearing capacity and post-earthquake seismic toughness of the repaired structure under complex stress conditions in active fault zones.

[0034] In this invention, the radial misalignment clearance 77 can be calculated using the following formula: ; In the formula, Radial misalignment clearance, i.e., the initial thickness of the elastic pad; The maximum allowable displacement (mm) between lining blocks is calculated and determined based on geological conditions and seismic fortification requirements. The ratio of the compressed thickness of the elastic pad to its initial thickness is generally taken in the range of 0.6 to 0.8. K: Safety reserve coefficient, usually taken as 1.1 to 1.3.

[0035] Let the distance (spacing) between the first and second steel plates be d. If d is too large, the sawtooth structure will not be able to enter an effective meshing state, and the third shear-resistant mechanism will not be able to activate properly. Therefore, the specific value of d should ensure that the sawtooth structure can enter a fully meshed state before the radial misalignment reaches the maximum allowable value. The specific value of d can be obtained through experiments or simulations. Generally, d can be determined as follows: ;in, This is the maximum radial displacement that can be generated by the lining section with the groove corresponding to the second steel plate 74. The central angle (in radians) of the lining section 61 corresponding to the second steel plate 74 is given in mm. : Radial misalignment clearance; D: Minimum thickness of the elastic pad after compression.

[0036] Similar to existing technologies, the first force transmission pad 75 in this invention can be made of nitrile cork rubber sheet, asbestos rubber sheet, asphalt felt, or latex cement board, etc.

[0037] In this invention, the groove can be located at both ends of the same lining section; alternatively, the groove can be located at one end of the same lining section, and the boss can be located at the other end. The latter is preferred, where the boss 71 is located at one end of the lining section 61, and the groove 72 is located at the other end. This latter configuration ensures reliable force transmission at the joint and good overall structural integrity.

[0038] In order to better transmit the load and make the boss and groove bear the force evenly, a second force transmission pad 80 is also provided between the inner side of the boss 71 and the inner side wall of the groove 72 (the side wall near the center of the tunnel).

[0039] To improve waterproofing, a compressible water-stop block 81 is provided within the circumferential clearance 79. It is understood that after installing the water-stop block 81, the width of the circumferential clearance 79 must be greater than the sum of the thickness of the first force-transmitting pad 75 and the compressed thickness of the water-stop block 81. The water-stop block 81 is generally made of rubber. The number of water-stop blocks can be set as needed. In this invention, there are two water-stop blocks 81, respectively disposed on both sides of the groove.

[0040] In some embodiments, there are one or more prestressed steel bars. Preferably, in this invention, there are two prestressed steel bars 76 respectively disposed on both sides of the groove 72.

[0041] like Figure 2 As shown, the waterproof layer 4 is provided with a U-shaped structure at the joint of the lining section 61. The U-shaped structure is used to generate adaptive tensile deformation when the lining section 61 slips relative to each other, so as to avoid the waterproof layer 4 being torn or damaged.

[0042] The present invention also provides a post-earthquake tunnel repair structure, including a waterproof layer 4 disposed inside the tunnel and a lining structure disposed inside the waterproof layer 4. The lining structure includes multiple lining segments 61 arranged sequentially along the circumference of the tunnel; any two adjacent lining segments 61 are connected by a multi-stage shear structure. The multi-stage shear structure adopts the same structure as the multi-stage shear structure described above.

Claims

1. A method for post-earthquake tunnel repair, characterized in that, Includes the following steps: S1. The three-dimensional distribution of the structural fracture zone (2) behind the tunnel crack was determined by ground-penetrating radar, and the treatment scope was determined based on the determined three-dimensional distribution of the structural fracture zone (2). S2. Based on the determined three-dimensional distribution of the structural fracture zone (2), grouting anchors (3) are driven from the original tunnel lining into the structural fracture zone (2) and grouting is performed. S3. Remove the original tunnel lining within the treatment area and lay a waterproof layer (4). S4. A new lining structure (6) is constructed inside the waterproof layer (4). The lining structure includes multiple lining sections (61) arranged sequentially along the circumference of the tunnel. Any two adjacent lining sections (61) are connected by a multi-stage shear structure. The multi-stage shear structure includes prestressed steel bars (76), a first steel plate (73), a second steel plate (74), a groove (72), a boss (71), a radial misalignment gap (77), a circumferential clearance gap (79), and a first force transmission pad (75); wherein, the groove (72) is provided on one end face of two adjacent lining sections (61), the boss (71) is provided on the other end face, and the boss (71) is inserted into the groove (72); the first steel plate (73) is provided on the end face of the boss (71), and the second steel plate (74) is provided on the bottom surface of the groove (72); both the first steel plate (73) and the second steel plate (74) have a serrated structure on their facing surfaces, and the first steel plate (73) and the second steel plate (74) are also provided with a serrated structure. (74) A first force transmission pad (75) is provided between them; one end of the prestressed steel bar (76) is connected to one of the two adjacent lining sections (61), and the other end is connected to the other section, so that the first steel plate (73) and the second steel plate (74) abut against each other through the first force transmission pad (75); a gap is provided between the outer side of the boss (71) and the outer side wall of the groove (72) to form the radial misalignment gap (77), and a compressible elastic pad (78) is provided in the radial misalignment gap (77); a gap is provided between the opposing end faces of the two adjacent lining sections (61) to form the circumferential clearance gap (79); the width of the circumferential clearance gap (79) is greater than the distance between the first steel plate (73) and the second steel plate (74).

2. The post-earthquake tunnel treatment method as described in claim 1, characterized in that, The distance between the first steel plate (73) and the second steel plate (74) is d. ;in: This is the maximum radial displacement that the lining section (61) corresponding to the second steel plate (74) can produce; The central angle of the lining section (61) corresponding to the second steel plate (74); : Radial misalignment clearance (77); D: Minimum thickness of the elastic pad (78) after compression.

3. The post-earthquake tunnel treatment method as described in claim 1, characterized in that, The lining section (61) has a boss (71) at one end and a groove (72) at the other end.

4. The post-earthquake tunnel treatment method as described in claim 1, characterized in that, A second force transmission pad (80) is provided between the inner side of the boss (71) and the inner sidewall of the groove (72).

5. A method for post-earthquake tunnel treatment as described in claim 1, characterized in that, The circumferential clearance (79) is provided with a compressible waterstop block (81).

6. A method for post-earthquake tunnel restoration as described in claim 1, characterized in that, The waterproof layer (4) is provided with a U-shaped structure at the joint of the lining section (61).

7. A post-earthquake tunnel repair structure, characterized in that, It includes a waterproof layer (4) disposed inside the tunnel and a lining structure disposed inside the waterproof layer (4). The lining structure includes multiple lining sections (61) arranged sequentially along the circumference of the tunnel. Any two adjacent lining sections (61) are connected by a multi-stage shear structure. The multi-stage shear structure includes prestressed steel bars (76), a first steel plate (73), a second steel plate (74), a groove (72), a boss (71), a radial misalignment gap (77), a circumferential clearance gap (79), and a first force transmission pad (75); wherein, the groove (72) is provided on one end face of two adjacent lining sections (61), the boss (71) is provided on the other end face, and the boss (71) is inserted into the groove (72); the first steel plate (73) is provided on the end face of the boss (71), and the second steel plate (74) is provided on the bottom surface of the groove (72); both the first steel plate (73) and the second steel plate (74) have a serrated structure on their facing surfaces, and the first steel plate (73) and the second steel plate (74) are also provided with a serrated structure. (74) A first force transmission pad (75) is provided between them; one end of the prestressed steel bar (76) is connected to one of the two adjacent lining sections (61), and the other end is connected to the other section, so that the first steel plate (73) and the second steel plate (74) abut against each other through the first force transmission pad (75); a gap is provided between the outer side of the boss (71) and the outer side wall of the groove (72) to form the radial misalignment gap (77), and a compressible elastic pad (78) is provided in the radial misalignment gap (77); a gap is provided between the opposing end faces of the two adjacent lining sections (61) to form the circumferential clearance gap (79); the width of the circumferential clearance gap (79) is greater than the distance between the first steel plate (73) and the second steel plate (74).

8. The post-earthquake tunnel repair structure as described in claim 7, characterized in that, The thickness of the first force transmission pad (75) is d. ;in: This is the maximum radial displacement that the lining section (61) corresponding to the second steel plate (74) can produce; The central angle of the lining section (61) corresponding to the second steel plate (74); : Radial misalignment clearance (77); D: Minimum thickness of the elastic pad (78) after compression.

9. The post-earthquake tunnel repair structure as described in claim 7, characterized in that, The lining section (61) has a boss (71) at one end and a groove (72) at the other end.

10. The post-earthquake tunnel repair structure as described in claim 7, characterized in that, The circumferential clearance (79) is provided with a compressible waterstop block (81).

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