Method for reinforcing cracked power transmission tower foundation by sticking multidirectional CFRP (carbon fiber reinforced plastic) cloth

Abstract

The invention discloses a method for reinforcing a cracked transmission tower foundation by pasting multidirectional CFRP cloth. The method comprises the following steps: cleaning and purifying a crack area; the crack with the small width is sealed through a low-pressure glue injection method; the crack with the large width is sealed through high-pressure grouting; a waterproof protection layer is painted; axial CFRP cloth is laid on the upper surface and the periphery of the foundation; circumferential CFRP cloth is laid on the side wall of the periphery of the foundation; and curing the reinforcing system. According to the method for reinforcing the cracked power transmission tower foundation by pasting the multidirectional CFRP cloth, crack reinforcing treatment can be more thorough, the reinforcing effect is more durable, the uplift bearing capacity of the foundation is improved, and the situation that the top face of the foundation cracks again due to tension after being repaired is avoided.

Description

Technical Field

[0001] This invention relates to the field of reinforcement of cracked foundations of overhead transmission line towers, and in particular to a method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric. Background Technology

[0002] During operation, the foundations of transmission towers often bear complex loads such as the weight of the entire tower, wind loads, and conductor tension, making them a crucial component for ensuring the stable operation of transmission lines. With the continuous development and expansion of power grids, transmission lines often traverse special areas such as mountainous regions and lakes. Over long-term operation, these lines are susceptible to cracking due to various factors, including corrosive environments, uplift loads, and downlift loads. Cracks not only affect the overall load-bearing capacity of the structure but also allow rainwater, surface water, and corrosive substances to seep into the structure, accelerating steel corrosion and concrete cracking, ultimately jeopardizing the operational safety of the entire transmission line.

[0003] Carbon fiber reinforced polymer (CFRP) composites have been widely used in the reinforcement and repair of structures such as bridges, tunnels, and civil buildings due to their advantages such as light weight, high strength, corrosion resistance, and convenient construction. CFRP reinforcement cages are constructed by directly bonding CFRP fabric to the surface in one direction or by fabricating CFRP sheet stirrups and CFRP longitudinal reinforcement to reinforce concrete structures.

[0004] A similar approach is as follows: CN115573273A proposes a method for repairing fatigue cracks in orthotropic steel bridge decks using a combination of shape memory alloy (SMA) and CFRP fabric. Specifically, a prefabricated SMA patch is placed at the crack location and heated to generate prestress, followed by the application of CFRP fabric for reinforcement. Its drawbacks are: the crack is not pre-filled during treatment, potentially causing it to extend further into the interior after reinforcement; furthermore, the CFRP reinforcement fabric is only applied unidirectionally to the crack surface, failing to create multi-directional stress constraints and thus unable to prevent crack propagation in other directions.

[0005] CN118835828A proposes a method for reinforcing concrete beam structures using CFRP (Cemented Plastic Reinforced Polymer) fabric. Specifically, the concrete surface is cleaned and cracks are sealed. Next, the reinforcement area is determined and moistened to facilitate the application of magnesium phosphate inorganic adhesive for bonding the CFRP fabric. Finally, appropriately sized CFRP fabric is bonded to the designated area to complete the reinforcement. While this method emphasizes crack sealing, it has several drawbacks: concrete beam structures are typical bending members, and their stress mechanisms differ significantly from those of transmission tower pile foundations, which are subjected to tension, compression, and interaction with the soil. Furthermore, this method is designed for planar structures; directly applying it to curved surfaces can lead to poor adhesion, making it unsuitable for reinforcing transmission tower pile foundations. Additionally, it neglects waterproofing, and the intrusion of moisture and acids / alkalis can cause secondary cracking after reinforcement.

[0006] Similarly, CN119041731A proposes a method for reinforcing concrete columns using high-temperature resistant inorganic adhesive to bond CFRP fabric. Specifically, the concrete column surface is pretreated, followed by the preparation of high-temperature resistant inorganic adhesive and CFRP fabric, and then bonding them together. Its disadvantages are: it is suitable for regular cylindrical components but cannot meet the continuous bonding requirements at the connection between the upper surface and the curved surface of a tower foundation; the overall effect is still unidirectional reinforcement, ignoring multidirectional synergistic effects; and it only considers the reliability of reinforcement under high-temperature conditions, neglecting waterproofing protection. The intrusion of moisture and acids / alkalis may lead to secondary cracking after reinforcement.

[0007] CN119616138 proposes a method for improving the seismic performance of concrete columns using seismic-resistant CFRP reinforcement. Specifically, it involves combining CFRP sheet stirrups and CFRP longitudinal bars to form a reinforcing cage, replacing the existing spiral rod stirrup structure to improve the seismic performance of concrete columns and solve the problem of poor seismic performance in existing CFRP-reinforced concrete columns. Its disadvantages are: excessive CFRP requirements leading to high costs; and the need for large-scale removal work to replace the original reinforcement in in-service concrete beam structures, resulting in limited environmental applicability. It is more suitable for new construction projects and not for rapid repair of existing reinforcement projects.

[0008] CN114562118A proposes a method for repairing damaged cracks in frame beam structures using a combination of U-shaped steel plates and CFRP (Concrete Composite Reinforced Polymer). Specifically, a cast-in-place concrete slab joint assembly is connected to the frame beam to be repaired. Then, a U-shaped steel plate is placed at the crack location and integrated with the cast-in-place concrete slab joint. Finally, CFRP fabric is horizontally bonded to reinforce the frame beam. Its disadvantages are: localized reinforcement with the U-shaped steel plate can lead to new stress concentration problems and uneven reinforcement; moreover, this reinforcement method is structurally complex, constituting a structural modification, and is not suitable for reinforcing operational structures such as power transmission tower foundations where space is limited after backfilling.

[0009] In summary, the existing reinforcement methods using CFRP composite materials are mainly focused on one-way direct surface bonding, which has the following disadvantages: (1) The existing CFRP reinforcement methods for cracks in reinforced concrete structures are mostly one-way direct surface bonding or partial wrapping methods for regular cubic structures such as beams, slabs, and cubic columns, and are not suitable for the reinforcement of cylindrical pile foundations of transmission towers. If applied directly, it will lead to unreliable bonding during long-term operation, causing quality problems such as delamination and bulging, as well as insufficient improvement in bearing capacity leading to secondary cracking; (2) It ignores the treatment of the cracks inside, relying only on surface bonding or wrapping of CFRP materials for reinforcement, resulting in no actual repair of the cracks, and the cracks may continue to develop inside; (3) It lacks measures to isolate water and corrosive environments, which can easily lead to water seepage, steel rust swelling, etc., affecting the bonding strength of the structure and the reinforcement effect; (4) It requires large-area chiseling of the original structure, which consumes manpower and material resources and has a high cost. Summary of the Invention

[0010] The technical problem this invention aims to solve is to provide a method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric. Considering the characteristics of cracks on the top surface of the transmission tower foundation and the complexity of its stress, a systematic crack treatment and reinforcement method is designed, combining crack repair, corrosive environment isolation, and multi-directional CFRP fabric reinforcement. This method makes crack reinforcement more thorough and the reinforcement effect more durable, improves the foundation's uplift resistance, and prevents the foundation top surface from cracking again due to tension after repair. Simultaneously, circumferential bonding of CFRP fabric enhances the circumferential constraint force of the foundation, preventing secondary cracking after circumferential crack filling. Furthermore, this method improves construction efficiency and environmental adaptability, avoids large-scale demolition work, and effectively solves the problems of incomplete treatment, poor durability, and insufficient structural recovery capacity in existing technologies, meeting the safety requirements of power systems for the long-term stable operation of transmission tower foundations.

[0011] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric includes the following steps: S1: Cleaning and purification of cracked areas; S2: Low-pressure injection molding method for sealing narrow cracks; S3: High-pressure grouting to seal wide cracks; S4: Apply a waterproof protective layer; S5: Axial CFRP fabric is laid on the base surface and around the perimeter; S6: Circumferential CFRP fabric is laid on the four sides of the foundation; S7: Reinforcement system maintenance.

[0012] S1 specifically includes: S1.1: For cracks with a small width, use a high-pressure air gun to blow away the dust, particles and impurities on the surface; if you encounter hard blocky impurities, use an angle grinder to grind the surface to make the plane flat. S1.2: For cracks with a large width, the edges are chiseled away to form an inverted V-shape.

[0013] S2 specifically includes: S2.1: First, place the grouting device base. After the grouting device base is arranged, install the grouting device. S2.2: Using the grouting nozzle of the grouting machine, highly permeable epoxy resin adhesive is slowly injected along the crack direction under low pressure, so that the adhesive can fully diffuse and fill the crack; S2.3: After filling, use a scraper to remove excess adhesive to make the surface flat, and use a plastic sealant to seal and cure. After the adhesive has completely cured, remove the plastic sealant.

[0014] S3 specifically includes: S3.1: Drill holes near deeper cracks, with the depth controlled to two-thirds of the crack depth; S3.2: Place the high-pressure grouting tank on a flat surface and connect the high-pressure grouting tank to the high-pressure grouting nozzle using a connecting hose; S3.3: After setting up the high-pressure grouting equipment, use a high-pressure grouting pump to inject epoxy grouting material; start from the lowest point and gradually move upwards until it overflows the surface and stops. S3.4: Clean up any excess material, remove the grouting nozzle, and seal the hole for curing.

[0015] S4 specifically includes: S4.1: After ensuring the surface is clean and smooth, apply the waterproof material horizontally and allow it to dry after application. S4.2: After drying, apply a second coat of waterproofing material vertically, perpendicular to the first coat.

[0016] Both horizontal and vertical waterproofing materials are made of highly elastic polyurethane.

[0017] S5 specifically includes: S5.1: After the waterproof material has fully cured, determine the foundation reinforcement area and apply epoxy impregnation adhesive. Lay the pre-cut axial CFRP cloth along the upper surface and extension direction of the foundation. S5.2: During the laying process, use a foam roller to repeatedly roll from the center outwards to remove air bubbles and ensure dense and uniform adhesion; S5.3: If multiple layers of reinforcement are required, after the first layer has cured, stack the layers in the same direction, the number of layers...n Determined according to design requirements, its purpose is to improve the tensile bearing capacity of the foundation surface.

[0018] In S5.1, considering that the surface of the foundation in the extension direction is not a regular cubic structure, but a cylindrical structure with a certain curvature, when the axial CFRP cloth is laid in the extension direction after the upper surface is laid, it should be laid from the edge area downwards at an angle of 10°-30° towards the axis. The extension length is limited to cover the entire tension area of ​​the foundation and should not be extended to wrap the entire side of the foundation to avoid uneven circumferential stress.

[0019] S6 specifically includes: S6.1: Apply a layer of epoxy impregnating adhesive as a primer on the axially laid CFRP fabric in the extension direction; S6.2: The pre-cut circumferential CFRP fabric is pasted circumferentially around the side of the foundation. During the laying process, a foam roller is used to repeatedly roll along the pasting direction of the circumferential CFRP fabric to remove air bubbles and ensure that the circumferential CFRP fabric and the axial CFRP fabric are tightly bonded. S6.3: After wrapping around the loop once, overlap the overlapping part of the circumferential CFRP fabric.

[0020] In S6.3, the overlap length L It can be obtained from the following formula: ; In the formula: L This refers to the overlap length; This refers to the tensile stress that the CFRP fabric needs to bear; This refers to the design value of the tensile strength of the CFRP fabric. b This refers to the effective width of the CFRP fabric.

[0021] This invention provides a method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric, which has the following technical advantages: 1) This invention constructs a multi-directional CFRP reinforcement system by laying axial CFRP fabric on the upper surface and its extended arc surface of the foundation, and bonding circumferential CFRP fabric to the outer perimeter of the foundation. This system can simultaneously resist multi-directional loads such as uplift force, circumferential tensile force, and shear stress, making the foundation stress more balanced and significantly improving the crack resistance of the foundation structure.

[0022] 2) The multi-directional CFRP fabric reinforcement system used in this invention can form cross constraints in different directions, which can effectively suppress the further expansion of cracks in the vertical and circumferential directions; at the same time, it makes the stress distribution in the reinforcement area more uniform, thereby preventing secondary cracking after repair; in addition, the depth filling work of the crack in the early stage also effectively ensures that the crack will not expand and diverge after the multi-directional CFRP fabric is pasted for reinforcement.

[0023] 3) This invention avoids the large-scale chiseling of cracked parts in crack treatment, making the operation more convenient, saving construction costs and shortening the construction cycle.

[0024] 4) This invention fully considers the necessity of a waterproof protective layer, which can prevent the steel reinforcement from rusting due to the intrusion of moisture and acid and alkali substances, thus avoiding the problem of cracking again after the foundation is reinforced. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a cross-sectional view of the cracked foundation structure in this invention.

[0026] Figure 2 This is a schematic diagram of the low-pressure injection method for filling cracks in this invention.

[0027] Figure 3 This is a schematic diagram of the high-pressure grouting method for filling cracks in this invention.

[0028] Figure 4 This is a front view of the horizontal waterproof protective layer applied to the base surface in this invention.

[0029] Figure 5 This is a top view of the horizontal waterproof protective layer applied to the base surface in this invention.

[0030] Figure 6 This is a front view of the longitudinal waterproof protective layer applied to the base surface in this invention.

[0031] Figure 7 This is a top view of the longitudinal waterproof protective layer applied to the base surface in this invention.

[0032] Figure 8 This is a front view of the axial CFRP fabric laid on the foundation in this invention.

[0033] Figure 9 This is an enlarged schematic diagram of the axial CFRP cloth laid on the foundation in this invention.

[0034] Figure 10 This is a front view of the circumferential CFRP fabric laid on the foundation in this invention.

[0035] Figure 11 This is a top view of the circumferential CFRP fabric laid on the foundation in this invention.

[0036] Figure 12 This is a flowchart of the construction scheme of the present invention.

[0037] In the diagram: 1. Cracked foundation; 2. Small crack; 3. Large crack; 4. Cracked area; 5. Grouting device base; 6. Grouting device; 7. Grouting nozzle; 8. High-pressure grouting tank; 9. Connecting hose; 10. High-pressure grouting nozzle; 11. High-pressure grouting pump; 12. Apply waterproof material laterally; 13. Apply waterproof material longitudinally; 14. Axial CFRP cloth; 15. Circumferential CFRP cloth. Detailed Implementation

[0038] A method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric includes the following steps: S1: Cleaning and purification of cracked areas. For example... Figure 1 As shown, before the crack filling work, the cracked area 4 of the cracked foundation 1 is first cleaned and purified.

[0039] S1.1: For narrow cracks 2, use a high-pressure air gun to blow away dust, particles, and impurities from the surface and inside the crack. If hard, blocky impurities are encountered, it may be necessary to use an angle grinder to grind the surface to ensure flatness and facilitate subsequent filling work.

[0040] S1.2: For cracks 3 with a larger width, the edges need to be chiseled away to form an inverted V-shape, which is beneficial for subsequent filling with adhesive material.

[0041] After the cleaning and purification work in the cracked area is completed, the crack filling operation is carried out.

[0042] S2: Low-pressure injection molding method for sealing narrow cracks. For example... Figure 2 As shown, for crack 2 with a smaller width, low-pressure injection is used to seal the crack.

[0043] S2.1: First, place the grouting device base 5. After the grouting device base 5 is arranged, install the grouting device 6. S2.2: Using the grouting nozzle 7 of the grouting device 6, highly permeable epoxy resin adhesive is slowly injected along the crack direction under low pressure to ensure that the adhesive can fully diffuse and fill the crack.

[0044] S2.3: After filling, scrape off the excess adhesive with a scraper to ensure a smooth surface, and seal the opening with a plastic sealant for at least 24 hours. Remove the plastic sealant after the adhesive has completely cured.

[0045] S3: As Figure 3 As shown, high-pressure grouting was used to treat the crack 3, which has a relatively large width.

[0046] S3.1: Drill holes near deeper cracks, with the depth controlled to about two-thirds of the crack depth; S3.2: Place the high-pressure grouting tank 8 on a flat ground and connect the high-pressure grouting tank 8 to the high-pressure grouting nozzle 10 using the connecting hose 9.

[0047] S3.3: After setting up the high-pressure grouting equipment, use the high-pressure grouting pump 11 to inject the epoxy grouting material; start from the lowest point and gradually move upwards until it overflows the surface and stops. S3.4: Clean up any excess material, pull out the high-pressure grouting nozzle 10 and seal the hole for curing. The curing time shall not be less than 48 hours.

[0048] S4: Apply a waterproof protective layer. After all cracks have been filled and fully cured, apply a high-elasticity polyurethane waterproofing material to the cracked base 1 surface to prevent the intrusion of moisture, chloride ions, and other corrosive media into the reinforcing steel, thus avoiding further cracking of the concrete.

[0049] S4.1: After ensuring the surface is clean and smooth, apply the waterproofing material using a traditional roller brush. Apply the first coat of waterproofing material 12 horizontally, and allow it to dry completely. S4.2: Apply the second coat perpendicular to the first coat, applying the waterproof material 13 vertically. This will enhance the tightness of the application and ensure that there are no gaps where the material has not been applied.

[0050] S5: Lay axial CFRP reinforcement fabric on the base surface and in the extension direction.

[0051] S5.1: After the waterproof material has fully cured, determine the foundation reinforcement area and apply epoxy impregnation adhesive. Lay the pre-cut axial CFRP cloth 14 along the upper surface of the foundation and the direction of crack extension.

[0052] Considering that the surface along the direction of the foundation crack is not a regular cubic structure, but rather a cylindrical structure with a certain curvature, the axial CFRP fabric 14, after being laid on the upper surface, should be laid downwards from the edge area at an angle of 10°-30° towards the axis when extending in the direction of extension. The extension length is limited to covering the entire tension area of ​​the foundation and should not extend to wrap the entire side of the foundation to avoid uneven circumferential stress. The specific length depends on the reinforcement project.

[0053] S5.2: During the laying process, use a foam roller to repeatedly roll from the center outwards to remove air bubbles and ensure dense and uniform adhesion.

[0054] S5.3: After the first layer of axial CFRP fabric 14 has cured, overlay the second layer of axial CFRP fabric 14 in a direction perpendicular to it. The second layer of axial CFRP fabric 14 should cover the entire length of the crack to improve the tensile strength of the top surface of the foundation. Repeat the above steps, and the number of layers can be adjusted according to the severity of the cracking.n ; n =1, 2, 3... layers of axial CFRP fabric 14.

[0055] S6: Circumferential CFRP fabric is laid above the axial CFRP fabric extension area of ​​the foundation. After the axial CFRP fabric 14 is laid on the upper surface of the foundation and in the extension direction, the circumferential CFRP fabric 15 is adhered to the circumferential portion of the foundation exposed above the ground.

[0056] S6.1: Apply a layer of epoxy impregnating adhesive as a primer to the axially laid CFRP cloth 14 in the extension direction; S6.2: The pre-cut circumferential CFRP fabric 15 is circumferentially bonded around the foundation. During installation, a foam roller is used to repeatedly roll along the bonding direction of the circumferential CFRP fabric 15 to remove air bubbles and ensure a tight fit between the circumferential CFRP fabric 15 and the axial CFRP fabric 14. The purpose is to enhance the circumferential constraint of the foundation and prevent secondary cracking after reinforcement of circumferential cracks.

[0057] S6.3: Wherein, after one circumferential rotation, an overlap is made at the overlap portion (a) of the circumferential CFRP fabric 15. This is to avoid insufficient restraint due to an excessively small overlap length or saturation of the load-bearing capacity due to an excessively long overlap length, thus avoiding material waste. Overlap length L It can be obtained from the following formula: ; In the formula: L The overlap length is in mm. The tensile stress that the CFRP fabric needs to bear is expressed in N; This is the design value for the tensile strength of CFRP fabric, in N / mm². 2 ; b This refers to the effective width of the CFRP fabric, in mm. If no specific overlap length design value has been calculated, an overlap length of 100-200 mm should be used to meet the reinforcement requirements.

[0058] S7: Reinforcement System Curing. After all reinforcement work is completed, the construction area should be sealed off for curing, ensuring that the reinforcement layer cures naturally for at least 48 hours without interference. Additionally, a UV-resistant coating should be sprayed onto the reinforced area surface to improve the system's environmental adaptability and service life.

Claims

1. A method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric, characterized in that, Includes the following steps: S1: Cleaning and purification of cracked areas; S2: Low-pressure injection molding method for sealing narrow cracks; S3: High-pressure grouting to seal wide cracks; S4: Apply a waterproof protective layer; S5: Axial CFRP fabric is laid on the base surface and around the perimeter; S6: Circumferential CFRP fabric is laid on the four sides of the foundation; S7: Reinforcement system maintenance.

2. The method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric according to claim 1, characterized in that: S1 specifically includes: S1.1: For cracks with a small width (2), use a high-pressure air gun to blow away the dust, particles and impurities on the surface; if you encounter hard block impurities, use an angle grinder to grind the surface to make the plane flat. S1.2: For cracks with a larger width (3), the edges are chiseled away to form an "inverted V-shape".

3. The method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric according to claim 1, characterized in that: S2 specifically includes: S2.1: First, place the grouting device base (5). After the grouting device base (5) is arranged, install the grouting device (6). S2.2: Using the grouting nozzle (7) of the grouting device (6), the highly permeable epoxy resin adhesive is slowly injected along the crack direction under low pressure, so that the adhesive can fully diffuse and fill the crack. S2.3: After filling, use a scraper to remove excess adhesive to make the surface flat, and use a plastic sealant to seal and cure. After the adhesive has completely cured, remove the plastic sealant.

4. The method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric according to claim 1, characterized in that: S3 specifically includes: S3.1: Drill holes near deeper cracks, with the depth controlled to two-thirds of the crack depth; S3.2: Place the high-pressure grouting tank (8) on a flat ground and connect the high-pressure grouting tank (8) to the high-pressure grouting nozzle (10) using the connecting hose (9); S3.3: After setting up the high-pressure grouting equipment, use the high-pressure grouting pump (11) to inject the epoxy grouting material; start from the lowest point and gradually move upwards until it overflows the surface and stops. S3.4: Clean up any excess material, remove the grouting nozzle, and seal the hole for curing.

5. The method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric according to claim 1, characterized in that: S4 specifically includes: S4.1: After ensuring the surface is clean and flat, apply the waterproof material (12) horizontally and let it dry after application; S4.2: After drying, apply a second coat of waterproof material (13) in a vertical direction, perpendicular to the first coat.

6. The method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric according to claim 5, characterized in that: Both the horizontally applied waterproofing material (12) and the vertically applied waterproofing material (13) are high-elasticity polyurethane waterproofing materials.

7. The method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric according to claim 1, characterized in that: S5 specifically includes: S5.1: After the waterproof material has fully cured, determine the foundation reinforcement area and apply epoxy impregnation adhesive. Lay the pre-cut axial CFRP cloth (14) along the upper surface and extension direction of the foundation. S5.2: During the laying process, use a foam roller to repeatedly roll from the center outwards to remove air bubbles and ensure dense and uniform adhesion; S5.3: If multiple layers of reinforcement are required, after the first layer has cured, stack the layers in the same direction, the number of layers... n Determined according to design requirements, its purpose is to improve the tensile bearing capacity of the foundation surface.

8. The method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric according to claim 7, characterized in that: In S5.1, considering that the surface of the foundation extension direction is not a regular cubic structure, but a cylindrical structure with a certain curvature, when the axial CFRP cloth (14) is laid in the extension direction after the upper surface is laid, it is inclined and pasted from the edge area downwards at an angle of 10°-30° towards the axis. The extension length is limited to cover the entire tension area of ​​the foundation and should not be extended to wrap the entire side of the foundation to avoid uneven circumferential stress.

9. The method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric according to claim 1, characterized in that: S6 specifically includes: S6.1: Apply a layer of epoxy impregnating adhesive as a base coat on the axially laid CFRP cloth (14) in the extension direction; S6.2: The pre-cut circumferential CFRP cloth (15) is pasted circumferentially around the side of the foundation. During the laying process, a foam roller is used to repeatedly roll along the pasting direction of the circumferential CFRP cloth (15) to remove air bubbles and ensure that the circumferential CFRP cloth (15) and the axial CFRP cloth (14) are tightly bonded. S6.3: After wrapping around the loop once, overlap the overlapping part of the circumferential CFRP fabric (15).

10. The method for reinforcing cracked transmission tower foundations by bonding multi-directional CFRP fabric according to claim 9, characterized in that: In S6.3, the overlap length L It can be obtained from the following formula: ； In the formula: L This refers to the overlap length; This refers to the tensile stress that the CFRP fabric needs to bear; This refers to the design value of the tensile strength of the CFRP fabric. b This represents the effective width of the CFRP fabric.

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