A highway tunnel crack treatment method

Abstract

The application discloses a highway tunnel crack treatment method, to solve the problem that the existing treatment for different width cracks often adopts a single scheme, resulting in insufficient or excessive treatment. The application includes: checking and marking the tunnel lining cracks; according to the crack type and the number of each crack, the corresponding treatment scheme is designed; coating the primer layer; pasting the glass fiber mesh cloth layer; coating the surface sealing adhesive layer and other steps; the hierarchical treatment strategy is adopted for cracks of different widths, achieving the balance between technical effect and economic benefit; the glass fiber mesh cloth layer is bonded to the outer surface of the concrete base layer and covers the crack opening area, reducing stress concentration, improving the overall tensile and shear capacity, and effectively inhibiting crack expansion; the full-surface bonding design of "primer layer-glass fiber mesh cloth layer-surface sealing adhesive layer" is adopted, mechanical interlocking is formed, and the anti-peeling capacity is strong; the crack end is provided with an extension lock area to prevent the mesh cloth from peeling off.

Description

Technical Field

[0001] This application relates to the field of crack treatment technology, specifically to a method for treating cracks in highway tunnels. Background Technology

[0002] Due to their unique architectural structure, highway tunnels are affected by multiple factors such as region, geology, and environment. During the construction and operation phases, various cracks will appear in the concrete components of the tunnel, directly affecting its structural safety and durability.

[0003] Traditional methods for treating and repairing tunnel cracks include sealing, adhesive injection, steel plate reinforcement, and carbon fiber reinforcement. However, these methods often employ a single approach for cracks of varying widths, leading to either insufficient or excessive treatment. Furthermore, they suffer from limited crack resistance: the tensile strength of the adhesive layer alone is insufficient to effectively inhibit further crack propagation. Under temperature changes or vehicle vibration loads, the adhesive layer is prone to cracking, and the cracks can easily reflect to the surface.

[0004] Chinese patent CN203096961U discloses a repair structure for concrete cracks. The technical solution is as follows: the concrete crack is chiseled into a trapezoidal groove with a depth of 40-50mm. Cement slurry is applied to the bottom of the trapezoidal groove with a thickness of 2-3mm. Fine stone concrete is filled into the groove. Fiberglass cloth is placed in the middle of the groove and is attached to the reserved hole in the concrete structure with strong adhesive.

[0005] However, the aforementioned existing technologies still have the following shortcomings:

[0006] (1) Over-treatment may be necessary for micro-cracks (deep trenching, filling with concrete);

[0007] (2) Wide cracks are not adequately treated. Since wide cracks often penetrate the lining, there is often groundwater seepage and loosening of the surrounding rock behind the lining. Relying solely on fine stone concrete for filling has limited impermeability.

[0008] (3) When the fiberglass cloth is embedded in the middle of the groove, it can only play a certain role in reinforcing the local area of ​​the crack. When the crack tip generates concentrated stress, the internal interlayer cannot quickly diffuse the stress to the surrounding healthy concrete area. The treated crack is still prone to reflection or secondary cracking from the surface. At the same time, since the fiberglass cloth is wrapped by fine stone concrete, the tensile stress generated by the crack needs to be transmitted through the fine stone concrete to reach the fiberglass cloth. Its stress transmission path is long and inefficient.

[0009] (4) The fiberglass cloth is fixed in a dotted manner only by the strong adhesive in the reserved hole. When the temperature changes or external loads are applied, the fiberglass cloth is easy to peel off from the concrete surface, resulting in repair failure and secondary reflection.

[0010] (5) Under the stress concentration at the crack tip, the fiberglass cloth end is prone to lift and peel off from the concrete surface. Once peeling occurs, it will gradually extend to the middle of the cloth, causing the repair structure to be damaged from the end. Summary of the Invention

[0011] Therefore, this application provides a method for treating cracks in highway tunnels to solve the problems that existing treatments for cracks of different widths often use a single solution, resulting in insufficient or excessive treatment, as well as the problems of secondary reflection at the ends and poor crack suppression effect.

[0012] To achieve the above objectives, this application provides the following technical solution:

[0013] A method for treating cracks in highway tunnels includes the following steps:

[0014] S1. Inspect, mark, and measure the width of cracks in the tunnel lining, and determine the type of crack based on the crack width:

[0015] When the crack width is less than 0.20 mm, it is judged as a micro-crack;

[0016] When the crack width is between 0.20mm and 3.0mm, it is judged as a medium-sized crack;

[0017] A crack is considered a wide crack if its width is greater than 3.0 mm.

[0018] S2. Based on the type of crack and the number of each type of crack, design corresponding treatment plans:

[0019] S21. For micro-cracks, the surface sealing method shall be adopted;

[0020] S22. For medium-sized cracks, use the surface sealing + glue injection method;

[0021] S23. For wide cracks, use the surface sealing + grouting method;

[0022] S3. Apply primer layer: Apply a primer layer along the outer surface of the tunnel concrete base layer to cover the crack opening area;

[0023] S4. Adhere the fiberglass mesh layer: Adhere the fiberglass mesh layer along the upper surface of the base layer, and the fiberglass mesh layer is adhered from top to bottom and from left to right along the base layer, using a scraper to roll and compact it back and forth; the ends of the cracks have extended locking areas;

[0024] S5. Apply a top layer of sealing adhesive: After the fiberglass mesh layer is pasted, apply a top layer of sealing adhesive along the upper surface of the fiberglass mesh layer, and roll and spread it to integrate with the mesh.

[0025] The base layer, the fiberglass mesh layer, and the top sealing layer together constitute a composite reinforcement layer, and the coverage area of ​​the composite reinforcement layer in the crack area is greater than that of the crack itself.

[0026] Optionally, it also includes:

[0027] S6. Applying a repair coating: After the cracks are sealed and the colloid has cured, use a grinder or polisher to polish the surface; then apply the repair coating.

[0028] Optionally, S21, for micro-cracks, a surface sealing method is used, including:

[0029] S211. Concrete base surface treatment: Use a grinder or wire brush to grind along the crack direction in an area of ​​about 5-12cm to remove the laitance, sand, loose concrete blocks, and carbonized layer on the concrete surface until fresh concrete is exposed; if there is oil, wipe it clean with acetone or industrial alcohol, and dry the damp section with a blowtorch to keep it clean and dry.

[0030] S212. Applying a filler layer: A filler layer is applied along the surface of the micro-cracks. Specifically, a special putty knife is used to fill and embed the adhesive along the surface of the micro-cracks, and the operation is performed perpendicular to the crack to ensure that the adhesive overflows throughout the crack. Finally, the excess adhesive around the crack is removed to reveal the crack line.

[0031] Optionally, S22, for medium-sized cracks, a surface sealing + adhesive injection method is used, including:

[0032] S221. Chiseling and crack surface treatment: Widen the crack and cut groove manually or mechanically; then, use a grinder or wire brush to grind along the crack direction in an area of ​​about 5-12cm wide to remove the laitance, sand, loose concrete blocks, and carbonized layer from the concrete surface until fresh concrete is exposed; if there is oil, wipe it clean with acetone or industrial alcohol, and dry the damp section with a blowtorch to keep it clean and dry.

[0033] S222, Setting up injection bases: Multiple injection bases are set at intervals on both sides of the medium crack along the direction of the concrete base layer. The injection bases are fixed to the surface of the concrete base layer by adhesive bonding and are equipped with plugs.

[0034] S223. Applying a filler layer: Apply a filler layer along the surface of the medium crack. Specifically, use a special putty knife to fill and embed the glue along the crack, and operate perpendicular to the crack to ensure that the glue overflows into the entire crack except for the glue base. Finally, remove the excess glue around the crack to reveal the crack line.

[0035] S224. Air pressure test: After the filler layer has hardened, conduct an air pressure test; specifically: first seal the filling base with a plug; compressed gas passes through one of the filling bases, with the air pressure controlled at 0.2-0.4 MPa, and soapy water is applied to the filler layer and around the filling base to observe whether there is any leakage;

[0036] S225. Grouting of Concrete Structural Adhesive: ① Use an grouting device to inject adhesive into the grouting holes. The injection sequence is from bottom to top, one hole at a time, continuously. The injection pressure is 0.22-3 MPa. When adhesive begins to overflow from adjacent holes, maintain the pressure for 3-5 minutes, then stop grouting the current hole and move to the next adjacent hole. ② During the grouting process, pay attention to controlling the pressure. For cracks with larger widths, if the adhesive flow is smooth, the pressure should be controlled at 2 MPa. If the adhesive flow is obstructed, the pump pressure can be controlled at 3 MPa. ③ Injection sequence: For horizontal cracks, it is advisable to gradually press from the lower end to the higher end; for vertical cracks, press from the bottom to the top. After pressing from one end, when the adhesive overflows from the grouting base at the other end after expelling the gas in the crack at the same rate as the injected grout, the grouting can be stopped. ④ For cracks that have been grouted, after the adhesive has cured, remove the grouting bases one by one and smooth the grouting hole with special sealing putty.

[0037] Optionally, S23, for wide cracks, the surface sealing + grouting method is adopted, including:

[0038] S231. Chiseling and crack base surface treatment: Use machinery to make a V-shaped groove along the crack, with a width of 5-12cm and a depth of not less than 10cm. Then use a grinder or wire brush to grind and remove the laitance, sand, loose concrete blocks, and carbonized layer on the concrete surface along the crack direction within a range of about 5-13cm until fresh concrete is exposed. If there is oil, wipe it clean with acetone or industrial alcohol. Dry the damp section with a blowtorch and keep it clean and dry.

[0039] S232. Drilling and embedding grouting pipes: Multiple grouting holes are opened at intervals on both sides of the wide crack on the surface of the concrete base layer, which are connected to the internal cavity of the wide crack. Grouting pipes are pre-embedded in the grouting holes. The front end of the grouting pipe is extended into the internal cavity of the wide crack. The exposed length of the tail end of the grouting pipe meets the requirements for installing the grout stop plug and grouting joint. The grout stop plug is installed on the pipe body near the hole opening to ensure that it is in close contact with the hole wall to prevent the grout from flowing back from the hole opening during grouting. Alternatively, the hole opening can be sealed with quick-hardening cement or anchoring agent.

[0040] S233. Applying a filler layer: Apply a filler layer along the crack surface of the crack of equal width. Specifically, use modified epoxy colloid to fill and seal the V-groove until it is flush with the adjacent concrete surface.

[0041] S234. Air Pressure Test: After the V-groove area is sealed and hardened, an air pressure test is conducted. Specifically, compressed gas is passed through the grouting hole, and the air pressure is controlled at 0.2-0.4MPa. At this time, soapy water can be applied around the sealing strip to observe whether there is any leakage. For vertical seams, the air test can be conducted from bottom to top, and for horizontal seams, it can be conducted from the lower end to the upper end.

[0042] S235. Grouting fluid (such as BG-M2 butyl rubber sealant grouting): Connect the grouting pump and the grouting pipe, inject grout in sections and sequences, and control the grouting pressure; adopt the "drill a section, grout a section" or full hole one-time grouting method, dynamically adjust the flow rate and pressure. After the grouting is completed and waiting for it to set, seal the grouting hole and clean up the residual grout on site.

[0043] Optionally, a waterproof membrane is also provided between the primer layer and the concrete substrate layer.

[0044] Optionally, the glass fiber mesh layer is made of alkali-resistant glass fiber mesh, and its surface is provided with an alkali-resistant coating.

[0045] Optionally, the base layer, the top sealing layer, and the filler layer are all modified epoxy structural adhesives.

[0046] Secondly, a surface repair structure for treating micro-cracks in highway tunnels, employing the aforementioned method for treating highway tunnel cracks, includes:

[0047] The tunnel's concrete base layer contains micro-cracks;

[0048] A filler layer is applied to the surface of the micro-cracks.

[0049] The base coat is applied to the surface of the tunnel concrete base layer and covers the opening areas of micro-cracks;

[0050] A fiberglass mesh layer is adhered to the upper surface of the base adhesive layer, and the fiberglass mesh layer covers the opening area of ​​the microcrack, and extends outward from both ends of the microcrack in the length direction to form a locking area.

[0051] A sealing adhesive layer is applied to the upper surface of the glass fiber mesh layer.

[0052] Thirdly, a glue-injection repair structure for treating moderate cracks in highway tunnels, employing the aforementioned method for treating highway tunnel cracks, includes: a tunnel concrete base layer with moderate cracks; the concrete base layer has a joint-expanding groove along the direction of the moderate cracks.

[0053] The surface of the tunnel concrete base layer is coated with a base layer covering the opening area of ​​the medium crack. A fiberglass mesh layer is adhered to the upper surface of the base layer. The fiberglass mesh layer extends outward at both ends of the medium crack length direction to form a locking area. The upper surface of the fiberglass mesh layer is coated with a top layer sealing adhesive layer.

[0054] It is also equipped with a glue-filling mechanism, which includes a glue-filling device and a glue-filling base. Multiple glue-filling bases are arranged at intervals on both sides of the medium crack along the direction of the concrete base layer. The glue-filling base is provided with glue-filling holes along the axial direction. The glue-filling holes are connected to the internal cavity of the medium crack. The glue-filling device is connected to the tail end of the glue-filling base. A glue-filling layer is provided at the crack opening of the medium crack. The glue-filling layer is provided with avoidance holes at the positions where each glue-filling needle passes through.

[0055] Fourthly, a grouting repair structure for treating wide cracks in highway tunnels, employing the aforementioned method for treating highway tunnel cracks, includes: a tunnel concrete base layer with wide cracks; and a filling layer is provided at the crack opening corresponding to the wide crack.

[0056] The concrete base layer has a V-shaped groove along the direction of the wide crack, and the surface of the concrete base layer has multiple grouting holes that are connected to the internal cavity of the wide crack at intervals on both sides of the wide crack. A grouting pipe is pre-embedded in the grouting hole, the body of the grouting pipe is provided with an overflow hole, the front end of the grouting pipe extends into the internal cavity of the wide crack, and the tail end of the grouting pipe is connected to a grouting machine.

[0057] The surface of the tunnel concrete base layer is coated with a primer layer covering the opening area of ​​the wide crack. A fiberglass mesh layer is adhered to the upper surface of the primer layer. The fiberglass mesh layer extends outward at both ends of the wide crack to form locking areas, and a top sealing layer is coated on the upper surface of the fiberglass mesh layer. The primer layer, the fiberglass mesh layer, and the top sealing layer together constitute a composite reinforcement layer. The coverage area of ​​the composite reinforcement layer in both the width and length directions of the wide crack is larger than the wide crack itself.

[0058] A polymer waterproof membrane is also installed between the base layer and the concrete substrate.

[0059] Compared with the prior art, this application has at least the following beneficial effects:

[0060] 1. Based on further analysis and research of the problems in the prior art, this application provides a method for treating cracks in highway tunnels. It adopts a graded treatment strategy for cracks of different widths, such as using the matching surface sealing method for micro cracks, the surface sealing + glue injection method for medium cracks, and the surface sealing + grouting method for wide cracks. Compared with the existing technology of treating all cracks with a single solution, this application avoids the problems of over-treatment or under-treatment, and achieves a balance between technical effect and economic benefit.

[0061] A fiberglass mesh layer is bonded to the outer surface of the tunnel concrete substrate through a primer layer, covering the cracked areas. A top-coating sealant layer is applied to the upper surface of the fiberglass mesh layer. Together, the primer layer, fiberglass mesh layer, and top-coating sealant layer constitute a composite reinforcement layer, forming a high-modulus "stress absorption and dispersion layer." The high tensile strength of the fiberglass mesh restricts crack propagation, evenly distributing localized stress in the cracked area, significantly reducing stress concentration, and improving overall tensile and shear strength. This effectively inhibits crack generation and propagation, enhancing crack suppression. Simultaneously, the bonding of the fiberglass mesh layer creates a buffer zone in stress concentration areas. When concentrated stress at the crack tip is transferred to the mesh, it is quickly dispersed to a wider area, preventing excessive stress concentration and material damage.

[0062] When the stress at the crack tip is transferred to the concrete surface, it is directly transferred to the mesh through the primer layer, which shortens the stress transfer path and improves the transfer efficiency, thus more effectively inhibiting the generation and propagation of cracks.

[0063] The design employs a full-surface bonding structure consisting of a base layer, a fiberglass mesh layer, and a top sealing layer. This allows the entire lower surface of the fiberglass mesh layer to bond to the concrete substrate through the base layer, while the entire upper surface is covered by the top sealing layer. The adhesive is interconnected through the mesh openings, forming a mechanically interlocking structure. This design results in a large bonding area, high bonding strength, strong peel resistance, and the ability to maintain the integrity of the composite reinforcement layer over a long period of time.

[0064] Furthermore, an extended locking zone is provided at the crack end to firmly anchor the fiberglass mesh to the healthy concrete area without cracks, effectively preventing the mesh from peeling off from the end and preventing the crack from continuing to extend towards the end.

[0065] 2. This application provides a surface repair structure for treating micro-cracks in highway tunnels, targeting medium-sized cracks. It uses a high-pressure injection process on the basis of a composite reinforcement layer to fill the crack with adhesive (modified epoxy structural adhesive). After the adhesive cures, it forms a chemical bond with the concrete of the crack wall, thereby restoring the overall load-bearing capacity of the structure, sealing the water seepage channels, and preventing water from seeping in along the crack.

[0066] 3. This application provides a grouting repair structure for treating wide cracks in highway tunnels. Based on a composite reinforcement layer, it is equipped with a surrounding rock grouting process to inject grout (cement grout or chemical grout) into the cracks of the surrounding rock to reinforce the surrounding rock, seal the seepage channels, and combine it with a polymer waterproof membrane to form a "waterproof + crack-resistant" protection system.

[0067] 4. The fiberglass mesh layer of this application uses alkali-resistant fiberglass mesh with an alkali-resistant coating on its surface, which effectively resists long-term erosion in a highly alkaline environment. It can ensure long-term performance stability in the alkaline environment of tunnel lining, effectively inhibit crack propagation, and ensure the material's resistance to deformation under stress. It also improves the bonding performance and weather resistance between the mesh and the modified epoxy structural adhesive and cement-based materials.

[0068] 5. The upper surface of the sealing adhesive layer of this application is also coated with a repair coating layer, which is a 380A epoxy coating, to further inhibit the colloid's UV protection and oxidation reaction. Attached Figure Description

[0069] To more intuitively illustrate the prior art and this application, exemplary drawings are provided below. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing this application; for example, based on the technical concept disclosed in this application and the exemplary drawings, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, size ratios, etc. of certain units (components).

[0070] Figure 1 This is a schematic flowchart of a method for treating cracks in a highway tunnel according to an embodiment of this application.

[0071] Figure 2 A plan view of a surface repair structure for treating microcracks in highway tunnels, provided in one embodiment of this application;

[0072] Figure 3 This is a cross-sectional schematic diagram of a surface repair structure for treating microcracks in highway tunnels, provided in one embodiment of this application.

[0073] Figure 4 for Figure 3 The diagram shown is a partial view.

[0074] Figure 5 for Figure 3 A schematic diagram showing a repair coating layer applied to the intermediate layer;

[0075] Figure 6 A plan view of an adhesive injection repair structure for treating medium cracks in highway tunnels, provided as an embodiment of this application;

[0076] Figure 7 A cross-sectional schematic diagram (with glue injection mechanism) of an adhesive injection repair structure for treating medium cracks in highway tunnels, provided as an embodiment of this application.

[0077] Figure 8 A cross-sectional schematic diagram (with composite reinforcement layer) of an adhesive injection repair structure for treating medium cracks in highway tunnels, provided as an embodiment of this application.

[0078] Figure 9 for Figure 6 The diagram shown is a partial view.

[0079] Figure 10 for Figure 6 A schematic diagram of a repair coating layer applied to the middle layer.

[0080] Figure 11 A cross-sectional schematic diagram of a grouting repair structure for treating wide cracks in a highway tunnel, provided as an embodiment of this application;

[0081] Figure 12 for Figure 11 The diagram shown is a partial view.

[0082] Figure 13 for Figure 12 A schematic diagram showing a repair coating layer applied to the intermediate layer;

[0083] Figure 14 A schematic diagram of a cross-sectional structure of a grouting repair structure for treating wide cracks in a highway tunnel, provided as an embodiment of this application;

[0084] Figure 15 A cross-sectional schematic diagram of a grouting repair structure for treating wide cracks in a highway tunnel, provided as another embodiment of this application;

[0085] Figure 16 for Figure 15 The diagram shows a grouting plan; the wide cracks in the diagram are construction circumferential joints.

[0086] Figure 17 This is a schematic diagram of a grouting repair structure for treating wide cracks in a highway tunnel, provided as an embodiment of this application; the wide cracks in the diagram are circumferential and diagonal cracks at the arch waist and arch foot.

[0087] Figure 18 A diagram showing the arrangement of grouting holes in a grouting repair structure for treating wide cracks in a highway tunnel, provided as an embodiment of this application.

[0088] Figure 19 for Figure 14 A partial schematic diagram of the first control valve and the second control valve shown;

[0089] Figure 20 for Figure 16 The cross-sectional view at point AA is shown.

[0090] Figure 21 for Figure 1 A schematic diagram of the glass fiber mesh layer in the diagram.

[0091] Explanation of reference numerals in the attached figures:

[0092] 1. Concrete base layer; 2. Micro-cracks; 3. Filler layer; 4. Primer layer; 5. Fiberglass mesh layer; 6. Topcoat sealing layer; 7. Repair coating layer; 8. Injection mechanism; 81. Injection device; 82. Injection base; 83. Adhesive; 9. Grouting hole; 10. Grout; 11. Injection needle; 111. Check needle; 12. Vent hole; 13. First control valve; 14. Second control valve; 15. Injection pipe; 16. Vent pipe; 17. Threaded joint; 18. Surrounding rock; 19. Medium crack; 20. Wide crack; 21. V-groove; 22. Waterproof membrane. Detailed Implementation

[0093] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0094] In the description of this application: unless otherwise stated, "a plurality of" means two or more. The terms "first," "second," "third," etc., in this application are intended to distinguish the objects referred to and do not have any special meaning in terms of technical connotation (e.g., they should not be construed as an emphasis on importance or order). Expressions such as "including," "comprising," and "having" also mean "not limited to" (certain units, components, materials, steps, etc.).

[0095] The terms used in this application, such as "upper," "lower," "left," "right," and "middle," are generally used to indicate the general relative positional relationship for the purpose of intuitive understanding by referring to the accompanying drawings, and are not absolute limitations on the positional relationship in the actual product.

[0096] One embodiment of this application, such as Figure 1 As shown, a method for treating cracks in highway tunnels includes the following steps:

[0097] S1. Inspect, mark, and measure the width of cracks in the tunnel lining, and determine the type of crack based on the crack width:

[0098] When the crack width δ is less than 0.20 mm, it is judged as a micro-crack 2;

[0099] When the crack width δ is 0.20mm-3.0mm, it is judged as a medium crack 19;

[0100] When the crack width δ is greater than 3.0 mm, it is judged as a wide crack 20;

[0101] S2. Based on the type of crack and the number of each type of crack, design corresponding treatment plans, including guiding the preparation of materials such as adhesive and fiberglass mesh:

[0102] S21. For micro-cracks 2, the surface sealing method is adopted;

[0103] S22. For medium-sized crack 19, the surface sealing + glue injection method is adopted;

[0104] S23. For wide crack 20, the surface sealing + grouting method is adopted;

[0105] S3. Apply primer layer 4 (apply primer): Apply primer layer 4 along the outer surface of the tunnel concrete base layer 1 to cover the crack opening area; the primer application should be carried out in the direction of the crack, the thickness of the primer should be thin and uniform, flat and straight, and after the application is completed, pay attention to protection to prevent debris from falling in.

[0106] S4. Adhere the fiberglass mesh layer 5: Adhere the fiberglass mesh layer 5 along the upper surface of the base layer 4, and the fiberglass mesh is adhered from top to bottom and from left to right along the base layer 4. The looseness should be such that it does not arch. Use a scraper to roll and compact it back and forth to ensure a flat and straight appearance. Ensure that the end of the crack has an extension lock area of ​​more than 10cm.

[0107] S5. Apply the surface sealing adhesive layer 6: After the glass fiber mesh layer 5 is pasted, apply the second layer of surface sealing adhesive (surface sealing adhesive layer 6) in time. Specifically, apply the surface sealing adhesive layer 6 along the upper surface of the glass fiber mesh layer 5, roll and spread it to integrate with the mesh. It is required that the application be flat and dense, with no bubbles or drips on the surface, and the lines be straight without wrinkles or curling edges.

[0108] The base layer 4, the fiberglass mesh layer 5, and the top sealing layer 6 together constitute a composite reinforcement layer. The coverage area of ​​the composite reinforcement layer in the crack area (such as the width direction and the length direction) is greater than that of the crack itself.

[0109] Preferably, it further includes:

[0110] S6. Apply repair coating layer 7 (appearance repair coating): After the crack is sealed and the colloid has cured, use a grinder or polisher to grind and polish it to remove dust and make it basically consistent with the color of the surrounding concrete; then, apply repair coating layer 7 to further inhibit the colloid's UV protection and oxidation reaction.

[0111] In step S21 above, such as Figures 2-5As shown, for the micro-crack 2, the surface sealing method is used, including:

[0112] S211. Concrete base surface treatment: First, use a grinder or wire brush to grind along the crack direction in an area of ​​about 5-12cm to remove the laitance, sand, loose concrete blocks, and carbonized layer on the concrete surface until fresh concrete is exposed; if there is oil, wipe it clean with acetone or industrial alcohol, and dry the damp section with a blowtorch to keep it clean and dry.

[0113] Subsequently, material preparation is carried out; the crack sealing material is a modified epoxy resin adhesive, and its various performance indicators must meet the industry standards and specifications. The adhesive is prepared and weighed strictly according to the specified mixing ratio; the mesh size of the glass fiber mesh layer 5 can be 3mm×3mm, and the width can be 8cm.

[0114] S212, Apply filler layer 3 (crack caulking): Apply filler layer 3 along the crack surface of the micro-crack 2. Specifically, use a special putty knife to fill and embed the adhesive along the crack surface of the micro-crack 2. During construction, pay attention to operating perpendicular to the crack to ensure that the adhesive overflows throughout the crack. Finally, remove the excess adhesive around the crack to reveal the crack line.

[0115] In step S22 above, such as Figures 6-10 As shown, for medium-sized crack 19, the surface sealing + glue injection method is adopted, including:

[0116] S221. Chiseling and Crack Treatment: Use manual labor or small machinery to widen and cut grooves to enhance the adhesion between the sealant and the concrete. Then, use a grinder or wire brush to grind along the crack direction for a width of about 5-12cm to remove laitance, sand, loose concrete blocks, and carbonized layer from the concrete surface until fresh concrete is exposed. If there is oil, wipe it clean with acetone or industrial alcohol. Dry damp sections with a blowtorch to keep them clean and dry.

[0117] S222, Setting up injection bases 82: Multiple injection bases 82 are set at intervals on both sides of the medium crack 19 along the surface of the concrete base layer 1. The injection bases 82 are fixed to the surface of the concrete base layer 1 by adhesive bonding. The spacing between adjacent injection bases 82 is 30cm-50cm, and the injection bases 82 are equipped with plugs.

[0118] S223, Apply filler layer 3 (crack caulking): Apply filler layer 3 along the crack surface of medium crack 19. Specifically, use a special putty knife to fill and embed the adhesive along the crack. During construction, pay attention to operating perpendicular to the crack to ensure that the adhesive overflows into the entire crack except for the position of the glue base 82. Finally, remove the excess adhesive around the crack to present the crack line shape.

[0119] S224. Air Pressure Test: After the filler layer 3 (sealing strip) has hardened, an air pressure test is conducted to check whether the sealing strip is sealed tightly. Specifically: First, seal the glue-filling base 82 through the plug; compressed gas is passed through one of the glue-filling bases 82 (glue nozzles), and the air pressure is controlled at 0.2-0.4 MPa. Soap water is applied to the sealing strip of the filler layer 3 and around the glue-filling base 82. If foam is found on the sealing strip after air is passed through, it indicates that the part is leaking and not sealed tightly. The leaking part is resealed to ensure a tight seal. For vertical seams, the air test can be conducted from bottom to top, and for horizontal seams, from the lower end to the upper end.

[0120] S225. Grouting of Concrete Structural Adhesive: ① Use grouting device 81 to grout adhesive 83 into the grouting holes. The grouting sequence is from bottom to top, one hole at a time, continuously. The grouting pressure of adhesive 83 is 0.22-3 MPa. When adhesive begins to overflow from adjacent holes, maintain the pressure for 3-5 minutes, then stop grouting in this hole and move to the adjacent grouting hole; ② During the grouting process, attention should be paid to controlling the pressure. For cracks with larger widths, if the adhesive flow is smooth, the pressure should be controlled at 2 MPa. If the adhesive flow from the crack is obstructed... The pump pressure can be controlled at 3 MPa; ③ Injection sequence: For horizontal cracks, it is advisable to gradually press from the low end to the high end; for vertical cracks, it is adsorbed from the bottom up; after pressing the glue from one end, when the glue injection base 82 at the other end releases the gas in the crack and the glue liquid 83 overflows at the same speed as the injected grout 10, the glue injection can be stopped; ④ Other work: For cracks that have been injected, after the glue liquid 83 has cured, remove the glue injection base 82 one by one, and smooth the grouting hole with special sealing putty to ensure a tight seal.

[0121] Preferably, the dispensing device 81 is a high-pressure dispensing machine or a syringe containing dispensing adhesive 83, wherein the adhesive 83 is a modified epoxy structural adhesive.

[0122] In step S23 above, such as Figures 11-20 As shown, for wide crack 20 (or severely leaking crack), the surface sealing + grouting method is adopted, including:

[0123] S231. Chiseling and crack base surface treatment: Use small machinery to cut a V-shaped groove 21 along the crack, with a width of 5-12cm and a depth of not less than 10cm. Then use a grinder or wire brush to grind and remove the laitance, sand, loose concrete blocks, and carbonized layer on the concrete surface along the crack direction within a range of about 5-13cm until fresh concrete is exposed. If there is oil, wipe it clean with acetone or industrial alcohol. Dry the damp section with a blowtorch and keep it clean and dry.

[0124] S232. Drilling and embedding grouting pipes 15: Multiple grouting holes 9 are opened at intervals on both sides of the wide crack 20, corresponding to the two sides of the crack 20, and are connected to the internal cavity of the crack 20. Grouting pipes 15 are pre-embedded in the grouting holes 9, and the front end of the grouting pipe 15 is inserted into the internal cavity of the crack 20. Specifically, drilling equipment is used to align with the marked point, and the angle of the drill rod is adjusted to ensure that the drilling direction is controlled by the external insertion angle α and the elevation angle β, so as to avoid the drilling bending, which would affect the insertion of the pipe and the grouting effect. After drilling to a reasonable depth, high-pressure air or water is used to grout the pipes. After cleaning the rock powder inside the hole to ensure unobstructed flow, manually or with the help of a drilling rig, insert the prepared grouting pipe 15 (with an overflow hole and a tapered front end) into the hole. If insertion is difficult, hammering or drilling can be used to push it in, ensuring that the pipe reaches the bottom of the hole. The exposed length of the tail of the grouting pipe 15 should meet the requirements for installing the grout stop plug and grouting joint (usually 15-30cm). Install the grout stop plug on the pipe near the hole opening to ensure that it fits tightly against the hole wall and prevents the grout 10 from flowing back from the hole opening during grouting, or seal the hole opening with quick-hardening cement or anchoring agent.

[0125] S233, Applying filler layer 3 (crack caulking): Apply filler layer 3 along the crack surface of the crack of equal width; specifically: use modified epoxy colloid to fill and seal the V-groove 21 until it is flush with the adjacent concrete surface.

[0126] S234. Air Pressure Test: After the V-groove 21 area is sealed and hardened, an air pressure test is conducted to check whether the sealing strip is sealed tightly. Specifically, compressed gas is passed through the grouting hole 9, and the air pressure is controlled at 0.2-0.4MPa. At this time, soapy water can be applied around the sealing strip. If foam is found on the sealing strip after air is passed through, it indicates that the part is leaking and not sealed tightly. The leaking part can be sealed again to ensure a tight seal. For vertical seams, the air test can be carried out from bottom to top, and for horizontal seams, from the lower end to the upper end.

[0127] S235, Grouting 10 (such as BG-M2 butyl rubber sealant grouting): Mix cement or chemical grout and other materials according to the ratio, pay attention to adding admixtures to adjust the setting time and fluidity, stir evenly and filter for later use; then connect the grouting pump and grouting pipe 15, inject grouting 10 in sections and sequences, and control the grouting pressure to generally 0.5-5MPa to avoid splitting the rock mass; adopt the "drill a section, inject a section" or full hole one-time grouting method, dynamically adjust the flow rate and pressure. After the grouting is completed and waiting for it to set, seal the grouting hole 9 and clean up the residual grouting 10 on site; strictly control the grouting ratio and grouting pressure, implement dynamic monitoring, and ensure that the grouting 10 effectively fills the cracks and improves the self-stability and impermeability of the surrounding rock 18.

[0128] Preferably, for wide cracks 20, a polymer waterproof membrane 22 is also provided between the base adhesive layer 4 and the concrete base layer 1 as the first waterproof barrier to seal the water seepage channels behind the lining; while the glass fiber mesh layer 5 serves as the second reinforcing layer to inhibit crack expansion and reflection. The two work together to effectively block cracks and form a continuous waterproof layer to prevent leakage.

[0129] More preferably, after step S2 and before step S3, the waterproof membrane 22 is laid, specifically including the following sub-steps:

[0130] (1) Apply roll material adhesive to the surface of the filler layer 3 and the surrounding concrete base layer 1;

[0131] (2) Lay the polymer waterproof membrane 22 on the base surface coated with adhesive, covering the entire length of the crack and extending to both sides;

[0132] (3) Use a scraper to roll from the middle of the roll outwards to remove the air between the roll and the base surface, so that the roll is fully adhered to the base surface;

[0133] (4) Subsequent construction: After the waterproof membrane 22 is laid, apply a base coat, attach a fiberglass mesh layer, and apply a top sealant layer to its surface in sequence.

[0134] Preferably, the base layer 4, the top sealing layer 6, and the filler layer 3 are all modified epoxy structural adhesives.

[0135] Preferably, such as Figure 21 As shown, the fiberglass mesh layer 5 is made of alkali-resistant fiberglass mesh, and its surface is coated with an alkali-resistant coating.

[0136] The alkali-resistant coating is an acrylic emulsion coating or a polyurethane coating;

[0137] The base material of the alkali-resistant fiberglass mesh is zirconium-titanium fiber.

[0138] The aforementioned alkali-resistant fiberglass mesh is designed to resist corrosion in highly alkaline environments. This mesh uses alkali-free glass fiber as the base material and is coated with an alkali-resistant acrylic or polyurethane coating, effectively resisting long-term erosion in highly alkaline environments. After immersion in an alkali-resistant solution, its tensile strength retention rate is ≥90%, ensuring long-term performance stability in the alkaline environment of tunnel lining. The warp and weft tensile strengths of the mesh are both ≥1000N / 50mm, effectively inhibiting crack propagation. The elongation at break of the mesh is ≤3%-5%, ensuring the material's resistance to deformation under stress. The alkali-resistant coating enhances the adhesion and weather resistance between the mesh and modified epoxy structural adhesives and cement-based materials.

[0139] More preferably, the mesh size of the glass fiber mesh layer 5 is 3mm×3mm-5mm×5mm, and the width of the glass fiber mesh layer 5 is 8cm. The specific dimensions can be adjusted according to the actual situation.

[0140] The mesh size of this application is moderate, making it easy to spread the adhesive during construction, and easy to position and roll the mesh fabric flat, resulting in high construction efficiency. Compared with mesh fabrics with excessively small mesh sizes (such as 1mm×1mm), the mesh size of this application improves the convenience of construction and reduces material costs and construction difficulty. Compared with mesh fabrics with excessively large mesh sizes (such as 10mm×10mm), this application ensures sufficient crack resistance and restraint, with more uniform mechanical properties and good crack resistance, achieving a reasonable balance between economy and performance.

[0141] Preferably, the extension length of the locking area is greater than or equal to 10cm.

[0142] Preferably, the width and length of the glass fiber mesh layer 5 are less than or equal to the width and length of the base adhesive layer 4 and the top sealing adhesive layer 6; the width and length of the base adhesive layer 4 and the top sealing adhesive layer 6 can be the same.

[0143] Preferably, the upper surface of the top layer sealing adhesive layer 6 is further coated with a repair coating layer 7, which is a 380A epoxy coating.

[0144] After the crack sealant has cured, it is polished using a grinder or polisher to remove dust and ensure it matches the color of the surrounding concrete. Depending on the scenario, further measures such as spraying a 380A epoxy coating on the surface can be taken to suppress the colloid's UV protection and oxidation reaction.

[0145] This application also provides a surface repair structure for treating micro-cracks in highway tunnels, such as... Figures 2-5 As shown, it includes:

[0146] The tunnel concrete base layer 1 has micro-cracks 2;

[0147] The filler layer 3 fills the crack surface of the micro-crack 2;

[0148] The base layer 4 is applied to the surface of the tunnel concrete base layer 1 and covers the opening area of ​​the micro-cracks 2.

[0149] A fiberglass mesh layer 5 is adhered to the upper surface of the base layer 4, and the fiberglass mesh layer 5 covers the opening area of ​​the microcrack 2, and extends outward from both ends of the microcrack 2 in the length direction to form a locking area.

[0150] A surface sealing adhesive layer 6 is coated on the upper surface of the fiberglass mesh layer 5.

[0151] This application also provides a glue-injection repair structure for treating medium-sized cracks in highway tunnels, such as... Figures 6-10 As shown, it includes: a tunnel concrete base layer 1 with a medium crack 19; the concrete base layer 1 has a joint widening groove along the direction of the medium crack 19;

[0152] The surface of the tunnel concrete base layer 1 is coated with a base layer 4 covering the opening area of ​​the medium crack 19. A fiberglass mesh layer 5 is attached to the upper surface of the base layer 4. The fiberglass mesh layer 5 extends outward at both ends of the medium crack 19 to form a locking area. The upper surface of the fiberglass mesh layer 5 is coated with a surface sealing layer 6.

[0153] It is also equipped with a glue injection mechanism 8, which includes a glue injection device 81 and a glue injection base 82. Multiple glue injection bases 82 are arranged at intervals along the direction of the medium crack 19 on the surface of the concrete base layer 1. The glue injection base 82 is provided with glue injection holes along the axial direction. The glue injection holes are connected to the internal cavity of the medium crack 19. The glue injection device 81 is connected to the tail end of the glue injection base 82. A glue filling layer 3 is provided at the crack opening of the medium crack 19. The glue filling layer 3 is provided with avoidance holes at the positions where each glue injection needle passes.

[0154] This application also provides a grouting repair structure for treating wide cracks in highway tunnels, such as... Figures 11-21 As shown, it includes: a tunnel concrete base layer 1 with wide cracks 20; a filler layer 3 is provided at the crack opening corresponding to the wide cracks 20.

[0155] A V-shaped groove 21 is provided along the direction of the wide crack 20 in the concrete base layer 1, and multiple grouting holes 9 are provided on the surface of the concrete base layer 1 at intervals on both sides of the wide crack 20, which are connected to the internal cavity of the wide crack 20. A grouting pipe 15 is pre-embedded in the grouting hole 9. The pipe body of the grouting pipe 15 is provided with an overflow hole, and the front end of the grouting pipe 15 extends into the internal cavity of the wide crack 20. The tail end of the grouting pipe 15 is connected to a grouting machine.

[0156] The surface of the tunnel concrete base layer 1 is coated with a base layer 4 covering the opening area of ​​the wide crack 20. A fiberglass mesh layer 5 is adhered to the upper surface of the base layer 4. The fiberglass mesh layer 5 extends outward at both ends of the wide crack 20 in the length direction to form an interlocking area. The upper surface of the fiberglass mesh layer 5 is coated with a surface sealing layer 6. The base layer 4, the fiberglass mesh layer 5 and the surface sealing layer 6 together constitute a composite reinforcement layer. The coverage area of ​​the composite reinforcement layer in both the width and length directions of the wide crack 20 is greater than that of the wide crack 20 itself.

[0157] A polymer waterproof membrane 22 is also installed between the base layer 4 and the concrete base layer 1.

[0158] Preferably, the concrete base layer 1 is provided with multiple vent holes 12 on both sides of the wide crack 20, which communicate with the internal cavity of the wide crack 20, and vent pipes 16 are pre-embedded in the vent holes 12.

[0159] A first control valve 13 and a second control valve 14 are respectively installed at the openings of the exhaust pipe 16 and the grouting pipe 15; the first control valve 13 and the second control valve 14 can be gate valves; a threaded direct pipe 17 is also installed inside the grouting pipe 15.

[0160] More preferably, the front end of the grouting pipe 15 is tapered, and the tail end of the pipe is provided with an exposed section. The length of the exposed section is usually 15-30cm. The exposed section is provided with a grouting joint connected to the grouting pump and is equipped with a grout stop plug. The grout stop plug is installed on the pipe near the borehole. The grout stop plug is a rubber plug or a mechanical expansion plug, used to prevent the grout 10 from flowing back from the borehole during grouting, or to seal the borehole with quick-hardening cement or anchoring agent.

[0161] Preferably, the grouting machine is a grouting pump; or an injection needle 11 is used, and the end of the injection needle 11 is also provided with a check needle 111.

[0162] This application forms a high-modulus "stress absorption and dispersion layer" by bonding a glass fiber mesh layer 5 to the existing structure (tunnel concrete base layer 1). Through its reinforcement, interlocking, and interface buffering functions, it fundamentally prevents or inhibits crack development. The principle is as follows:

[0163] The fiberglass mesh layer 5 is directly attached to the structural surface through an adhesive (modified epoxy structural adhesive) and covers the crack opening area to form an effective fusion. The high tensile strength of the fiberglass mesh further constrains and limits crack propagation, evenly distributes local stress in the crack area, and greatly reduces stress concentration. Its high toughness is coordinated and synchronized with the deformation of the concrete matrix, thereby effectively inhibiting crack development and preventing secondary cracking reflection. At the same time, this application adopts a full-surface bonding design of "adhesive (base adhesive layer 4) - mesh (fiberglass mesh layer 5) - adhesive (surface sealing adhesive layer 6)", which has a large bonding area and high bonding strength. The adhesive is mechanically interlocked through the mesh holes, which has strong anti-peeling ability and can maintain the integrity of the composite reinforcement layer for a long time.

[0164] Meanwhile, for medium-sized cracks 19 and wide cracks 20, adhesive 83 and grout 10 are filled inside the cracks, so that they form a chemical bond with the concrete of the crack wall. After curing, they are integrated with the concrete. Combined with the glass fiber mesh layer 5, it has good long-term stability, can block water seepage channels, and prevent water from seeping in along the cracks.

[0165] This application also includes an extended locking zone at the crack end, firmly anchoring the mesh fabric to the healthy concrete area without cracks, effectively preventing the mesh fabric from peeling off from the end and stopping the crack from continuing to extend towards the end. In terms of construction convenience, compared with traditional reinforcement methods (such as steel plate bonding), fiberglass mesh fabric is easy to construct, requires no large machinery, and can be carried out without interrupting traffic. It is particularly suitable for rapid maintenance of urban underground trunk roads. Fiberglass fabric has good flexibility and can be cut into any shape to fit the curved surface or irregular structure of the tunnel, such as the tunnel arch, arch waist, arch shoulder, equipment hole, etc. In terms of construction operation, the use of fiberglass mesh fabric is lightweight, the construction process is relatively simple, it is easy for construction personnel to operate and master, the pasting and installation are convenient, and the construction progress is relatively fast.

[0166] (1) Reinforcing and strengthening effect

[0167] The high tensile strength of fiberglass mesh allows it to act as an internal "skeleton," directly bearing and offsetting the tensile and shear stresses generated at the crack tip by temperature changes or other external loads. This is equivalent to adding "ribs" to the lining structure, greatly improving its overall tensile and shear resistance, thereby effectively inhibiting the generation and propagation of cracks.

[0168] (2) Stress dispersion and release

[0169] The adhesion of fiberglass mesh creates a buffer zone in areas of stress concentration. When the concentrated stress at the crack tip is transferred to the mesh, it is quickly dispersed to a larger surrounding area, preventing excessive stress concentration that could lead to material failure.

[0170] (3) Interface buffering effect

[0171] As an independent flexible layer, fiberglass mesh actually forms a "buffer zone" between the old structure (such as a concrete slab) and the new layer. This buffer layer can absorb some of the horizontal and vertical displacement from the cracks in the lower layer, thereby reducing the direct impact on the upper structure and forming a "buffer zone".

[0172] In addition, in practical applications, fiberglass mesh can also be used in combination with materials such as polyester fiberglass cloth (waterproof membrane). This composite structure can effectively prevent cracking and form a waterproof layer, preventing seepage behind the lining from forming leaks through cracks and avoiding tunnel water damage.

[0173] This application is applicable to the treatment of defects such as network shrinkage cracks, leakage, and spalling in highway tunnel linings. It can also be used for the repair and suppression of non-structural cracks (circumferential, longitudinal, oblique, crescent-shaped) in tunnel linings, specifically in the following ways:

[0174] (1) Enhanced tensile and crack resistance: The mesh itself has high tensile strength; after being pasted or laid on the lining surface, it can effectively share the tensile stress on the concrete structure, significantly inhibiting the generation and expansion of new and old cracks, especially suitable for the control and reinforcement of non-structural cracks; (2) Delayed reflection cracks: Laying high-strength mesh in the pavement overlay or lining reinforcement layer can effectively delay reflection cracks caused by the displacement of the underlying structure, and improve the overall integrity of the structure; (3) Adaptable to various crack morphologies: Whether longitudinal, circumferential, oblique, or more complex mesh shrinkage cracks and crescent cracks, the mesh can provide all-round constraint through its mesh structure, thus improving the overall stability of the structure; (4) Improve water resistance and waterproofing: When used with polymer mortar and polyester fiberglass cloth, a high-density composite protective layer can be formed, which can effectively block water seepage channels, significantly improve the water resistance of the structure, and prevent leakage; (5) Resist environmental erosion: The mesh cloth has corrosion resistance properties, which can effectively protect the lining structure from the erosion of environmental factors such as chloride ions and carbonization, delay the corrosion of steel bars and the deterioration of concrete, and extend the service life of the tunnel; (6) Repair surface erosion: For the weathering, peeling and flaking of the lining surface, the mesh cloth is used to reinforce and firmly "grab" the repair materials together, which solves the problem that the traditional plaster layer is easy to hollow and fall off again.

[0175] The technical features of the above embodiments can be combined in any way (as long as there is no contradiction in the combination of these technical features). For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; these embodiments not explicitly written should also be considered to be within the scope of this specification.

Claims

1. A method for treating cracks in highway tunnels, characterized in that, Includes the following steps: S1. Inspect, mark, and measure the width of cracks in the tunnel lining, and determine the type of crack based on the crack width: When the crack width is less than 0.20 mm, it is judged as a micro-crack; When the crack width is between 0.20mm and 3.0mm, it is judged as a medium-sized crack; A crack is considered a wide crack if its width is greater than 3.0 mm. S2. Based on the type of crack and the number of each type of crack, design corresponding treatment plans: S21. For micro-cracks, the surface sealing method shall be adopted; S22. For medium-sized cracks, use the surface sealing + glue injection method; S23. For wide cracks, use the surface sealing + grouting method; S3. Apply primer layer: Apply a primer layer along the outer surface of the tunnel concrete base layer to cover the crack opening area; S4. Adhere the fiberglass mesh layer: Adhere the fiberglass mesh layer along the upper surface of the base layer, and the fiberglass mesh layer is adhered from top to bottom and from left to right along the base layer, using a scraper to roll and compact it back and forth; the ends of the cracks have extended locking areas; S5. Apply a top layer of sealing adhesive: After the fiberglass mesh layer is pasted, apply a top layer of sealing adhesive along the upper surface of the fiberglass mesh layer, and roll and spread it to integrate with the mesh. The base layer, the fiberglass mesh layer, and the top sealing layer together constitute a composite reinforcement layer, and the coverage area of ​​the composite reinforcement layer in the crack area is greater than that of the crack itself.

2. The method for treating cracks in highway tunnels according to claim 1, characterized in that, Also includes: S6. Apply a repair coating: After the cracks are sealed and the colloid has cured, use a grinder or polisher to grind and polish the surface. Then, the repair coating layer is applied.

3. The method for treating cracks in highway tunnels according to claim 2, characterized in that, S21. For micro-cracks, the surface sealing method is used, including: S211. Concrete base surface treatment: Use a grinder or wire brush to grind along the crack direction in an area of ​​about 5-12cm to remove the laitance, sand, loose concrete blocks, and carbonized layer on the concrete surface until fresh concrete is exposed; if there is oil, wipe it clean with acetone or industrial alcohol, and dry the damp section with a blowtorch to keep it clean and dry. S212. Applying a filler layer: A filler layer is applied along the surface of the micro-cracks. Specifically, a special putty knife is used to fill and embed the adhesive along the surface of the micro-cracks, and the operation is performed perpendicular to the crack to ensure that the adhesive overflows throughout the crack. Finally, the excess adhesive around the crack is removed to reveal the crack line.

4. The method for treating cracks in highway tunnels according to claim 2, characterized in that, S22. For medium-sized cracks, the surface sealing + glue injection method is adopted, including: S221. Chiseling and crack surface treatment: Widen the crack and cut groove manually or mechanically; then, use a grinder or wire brush to grind along the crack direction in an area of ​​about 5-12cm wide to remove the laitance, sand, loose concrete blocks, and carbonized layer from the concrete surface until fresh concrete is exposed; if there is oil, wipe it clean with acetone or industrial alcohol, and dry the damp section with a blowtorch to keep it clean and dry. S222, Setting up injection bases: Multiple injection bases are set at intervals on both sides of the medium crack along the direction of the concrete base layer. The injection bases are fixed to the surface of the concrete base layer by adhesive bonding and are equipped with plugs. S223. Applying a filler layer: Apply a filler layer along the surface of the medium crack. Specifically, use a special putty knife to fill and embed the glue along the crack, and operate perpendicular to the crack to ensure that the glue overflows into the entire crack except for the glue base. Finally, remove the excess glue around the crack to reveal the crack line. S224. Air pressure test: After the filler layer has hardened, conduct an air pressure test; specifically: first seal the filling base with a plug; compressed gas passes through one of the filling bases, with the air pressure controlled at 0.2-0.4 MPa, and soapy water is applied to the filler layer and around the filling base to observe whether there is any leakage; S225. Grouting of Concrete Structural Adhesive: ① Use an grouting device to inject adhesive into the grouting holes. The injection sequence is from bottom to top, one hole at a time, continuously. The injection pressure is 0.22-3 MPa. When adhesive begins to overflow from adjacent holes, maintain the pressure for 3-5 minutes, then stop grouting the current hole and move to the next adjacent hole. ② During the grouting process, pay attention to controlling the pressure. For cracks with larger widths, if the adhesive flow is smooth, the pressure should be controlled at 2 MPa. If the adhesive flow is obstructed, the pump pressure can be controlled at 3 MPa. ③ Injection sequence: For horizontal cracks, it is advisable to gradually press from the lower end to the higher end; for vertical cracks, press from the bottom to the top. After pressing from one end, when the adhesive overflows from the grouting base at the other end after expelling the gas in the crack at the same rate as the injected grout, the grouting can be stopped. ④ For cracks that have been grouted, after the adhesive has cured, remove the grouting bases one by one and smooth the grouting hole with special sealing putty.

5. The method for treating cracks in highway tunnels according to claim 2, characterized in that, S23. For wide cracks, the surface sealing + grouting method is adopted, including: S231. Chiseling and crack base surface treatment: Use machinery to make a V-shaped groove along the crack, with a width of 5-12cm and a depth of not less than 10cm. Then use a grinder or wire brush to grind and remove the laitance, sand, loose concrete blocks, and carbonized layer on the concrete surface along the crack direction within a range of about 5-13cm until fresh concrete is exposed. If there is oil, wipe it clean with acetone or industrial alcohol. Dry the damp section with a blowtorch and keep it clean and dry. S232. Drilling and embedding grouting pipes: Multiple grouting holes are opened at intervals on both sides of the wide crack on the surface of the concrete base layer, which are connected to the internal cavity of the wide crack. Grouting pipes are pre-embedded in the grouting holes. The front end of the grouting pipe is extended into the internal cavity of the wide crack. The exposed length of the tail end of the grouting pipe meets the requirements for installing the grout stop plug and grouting joint. The grout stop plug is installed on the pipe body near the hole opening to ensure that it is in close contact with the hole wall to prevent the grout from flowing back from the hole opening during grouting. Alternatively, the hole opening can be sealed with quick-hardening cement or anchoring agent. S233. Applying a filler layer: Apply a filler layer along the crack surface of the crack of equal width. Specifically, use modified epoxy colloid to fill and seal the V-groove until it is flush with the adjacent concrete surface. S234. Air Pressure Test: After the V-groove area is sealed and hardened, an air pressure test is conducted. Specifically, compressed gas is passed through the grouting hole, and the air pressure is controlled at 0.2-0.4MPa. At this time, soapy water can be applied around the sealing strip to observe whether there is any leakage. For vertical seams, the air test can be conducted from bottom to top, and for horizontal seams, it can be conducted from the lower end to the upper end. S235. Grouting fluid (such as BG-M2 butyl rubber sealant grouting): Connect the grouting pump and the grouting pipe, inject grout in sections and sequences, and control the grouting pressure; adopt the "drill a section, grout a section" or full hole one-time grouting method, dynamically adjust the flow rate and pressure. After the grouting is completed and waiting for it to set, seal the grouting hole and clean up the residual grout on site.

6. The method for treating cracks in highway tunnels according to claim 5, characterized in that, A waterproof membrane is also installed between the base layer and the concrete substrate.

7. The method for treating cracks in highway tunnels according to claim 3, 4, or 5, characterized in that, The fiberglass mesh layer is made of alkali-resistant fiberglass mesh, and its surface is coated with an alkali-resistant coating.

8. The method for treating cracks in highway tunnels according to claim 3, 4, or 5, characterized in that, The base layer, top sealing layer, and filler layer are all modified epoxy structural adhesives.

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