Carbon fiber composite reinforced steel pipe concrete support system and construction method

Abstract

The application relates to the field of steel pipe concrete support, and particularly discloses a carbon fiber composite material reinforced steel pipe concrete support system and a construction method, which comprises resistance-increasing external-tooth steel pipes, a carbon fiber layer, a ground-glass fiber layer and longitudinal connecting steel bars; a plurality of resistance-increasing external-tooth steel pipes for supporting surrounding rocks are arranged along the longitudinal direction of the surrounding rocks, the resistance-increasing external-tooth steel pipes are internally filled with concrete, the carbon fiber layer is pasted outside the steel pipe body, and mechanical engagement is formed between the resistance-increasing external teeth and the carbon fiber layer; the ground-glass fiber layer is pasted outside the carbon fiber layer; and the longitudinal connecting steel bars pass through the plurality of steel pipe bodies along the longitudinal direction of the surrounding rocks, so that the steel pipe bodies are connected.

Description

Technical Field

[0001] This invention relates to the field of steel-concrete composite support, specifically to a carbon fiber composite reinforced steel-concrete composite support system and its construction method. Background Technology

[0002] In tunnel and underground engineering construction, steel-concrete composite (SCPC) support has advantages such as high strength and large load-bearing capacity, and is widely used in the support of tunnels and underground engineering in various strata. SCPC support and shotcrete together form the initial support structure for tunnels and underground engineering. However, in complex geological environments, such as those with strong corrosion and high stress, traditional SCPC initial support is prone to problems such as steel pipe corrosion, delamination at the interface between the steel pipe and shotcrete, and a decrease in overall load-bearing capacity, leading to a shortened support life and increased maintenance costs. Therefore, some existing technologies disclose techniques for adding carbon fiber to SCPC to improve the load-bearing capacity and durability of the support structure, as detailed in patents CN202248269U and CN202117165U. However, due to the smooth surface of carbon fiber, when further shotcrete is applied after the SCPC support is completed, the carbon fiber wrapping around the steel pipe can easily cause concrete rebound, affecting the shotcrete quality and causing excessive material consumption. Summary of the Invention

[0003] This invention aims to overcome the shortcomings of existing technologies and provide a carbon fiber composite reinforced steel pipe concrete support system and construction method. Through the corrosion protection and reinforcement of the carbon fiber layer, the interface resistance increase of the frosted fiber layer, the flange connection, and the rebar connector connection, the integrated effect of corrosion protection, interface strengthening and load-bearing capacity enhancement is achieved, thereby improving the durability, integrity and adaptability of the support structure to complex environments.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a steel tube concrete support system reinforced with carbon fiber composite material, comprising a friction-enhancing toothed steel tube, a carbon fiber layer, a frosted fiber layer, and longitudinal connecting steel bars. Several resistance-increasing toothed steel pipes are installed along the longitudinal direction of the surrounding rock for supporting the surrounding rock. The inside of the resistance-increasing toothed steel pipes is filled with concrete, and a carbon fiber layer is pasted on the outside of the steel pipe body. The resistance-increasing teeth and the carbon fiber layer are mechanically interlocked. A frosted fiber layer is pasted on the outside of the carbon fiber layer. Longitudinal connecting steel bars pass through several steel pipe bodies along the longitudinal direction of the surrounding rock to realize the connection between the steel pipe bodies.

[0005] The present invention uses a drag-enhancing external toothed steel pipe as the core load-bearing component, forming a combination of excellent compressive strength and high rigidity with the internal concrete filling. From the inside out, a frosted fiber layer and a carbon fiber layer are sequentially arranged on the outer side. The carbon fiber layer significantly reinforces the steel-concrete pipe, effectively improving the overall load-bearing capacity and ductility of the structure, while also possessing excellent corrosion resistance and fatigue resistance. The frosted fiber layer effectively reduces the rebound of shotcrete, improving construction results. When subjected to load, the carbon fiber layer inhibits the expansion and deformation of the steel pipe through lateral restraint, increasing compressive strength. The steel-concrete pipe provides rigid support for the carbon fiber layer, preventing local instability; the two complement each other's advantages.

[0006] As a further technical solution, the frosted fiber layer is composed of quartz sand and fiber filaments, which can effectively reduce the rebound of shotcrete and improve the construction effect. Its surface fiber filaments and frosted particles can greatly enhance the bonding force between the steel pipe concrete support and the shotcrete interface, avoid the peeling of the support interface, and improve the overall structure and stress transmission efficiency.

[0007] As a further technical solution, the aforementioned resistance-increasing external toothed steel pipe is provided with grouting holes and venting holes, wherein the grouting holes are used to inject high-strength concrete, and the venting holes are used to expel air to ensure dense filling.

[0008] As a further technical solution, a nut fixing hole is also provided on the side of the aforementioned resistance-increasing external toothed steel pipe, and a nut is fixed in the nut fixing hole. The nut is connected to the longitudinal connecting steel bar to form a continuous force transmission system.

[0009] As a further technical solution, the aforementioned resistance-enhancing external toothed steel pipe comprises multiple sections, with adjacent sections connected by sleeves and pins to form a shape that matches the surrounding rock; the sleeve is wrapped with a carbon fiber reinforcement layer.

[0010] As a further technical solution, a reinforcing plate is welded around the circumference of the external toothed steel pipe at the locations of the grouting hole and the vent hole.

[0011] Secondly, this invention also proposes a construction method for a carbon fiber composite reinforced steel-concrete composite support system, specifically including the following steps: Step 1: Pre-process the resistance-increasing external toothed steel pipe. The resistance-increasing external toothed steel pipe is opened with grouting holes, venting holes and nut fixing holes according to the design position; and a grout-stopping ring is attached inside the connecting sleeve. Step 2: Apply epoxy adhesive to the outside of the resistance-enhancing external toothed steel pipe to bond the carbon fiber layer, compact and smooth it, and tap it to make the mechanical engagement between the resistance-enhancing external teeth and the carbon fiber layer closer, ensuring no hollow areas or damage; apply epoxy adhesive again to bond the quartz sand and basalt fiber filaments to form a frosted fiber layer; screw the connecting nut into the nut fixing hole to compact the edge of the bonded carbon fiber layer and improve the bonding effect of the carbon fiber layer; Step 3: Tunnel excavation; Step 4: The external toothed steel pipes of the same steel arch frame are connected by sleeves and fixed with pins. The prefabricated steel arch frame is hoisted to the design position and fixed with temporary supports. Step 5: Install longitudinal reinforcing bars; Step 6: High-strength concrete is injected into the inner cavity of the steel pipe under high pressure through the grouting hole. During the grouting process, trapped air is discharged through the vent hole to ensure that the concrete is filled densely without voids. After the grouting is completed, it is cured according to the specifications until the concrete reaches the design strength. Step 7: Grouting hole sealing and reinforcement; Step 8: After the concrete inside the steel pipe reaches the required strength and all connection nodes and protective layers pass inspection, spray concrete onto the entire cross-section of the tunnel surrounding rock, the outer side of the steel arch frame, and the surface of the frosted fiber layer to ensure complete coverage without omission, forming a composite support structure in which the surrounding rock, sprayed concrete, and carbon fiber reinforced steel pipe concrete work together to further improve the overall stability and deformation resistance.

[0012] As a further technical solution, the processing method of the resistance-increasing external toothed steel pipe in step 1 is as follows: roughen the steel pipe to form uniform pits / microburrs to increase resistance, with a height similar to the thickness of the carbon fiber layer, to ensure close mechanical engagement with the carbon fiber and not affect the adhesion of the abrasive fiber layer.

[0013] As a further technical solution, in step 5, the longitudinal connecting steel bars are screwed into the connecting nuts, straightened and fixed to form a longitudinal force transmission skeleton, thereby improving the overall rigidity and deformation resistance of the support system.

[0014] As a further technical solution, in step 7, after the grouting concrete inside the friction-enhancing external toothed steel pipe reaches its initial setting strength, the laitance and debris on the surface of the steel pipe outside the grouting hole and vent hole are thoroughly cleaned; the grouting hole and vent hole are sealed with steel plates to ensure a tight seal; then, carbon fiber cloth is wrapped in a ring around the outside of the grouting hole and vent hole and the surrounding steel pipe surface with epoxy adhesive, and the carbon fiber cloth is compacted and smoothed to ensure that it is tightly attached to the steel pipe, grouting hole and vent hole without voids, which significantly enhances the structural integrity and crack resistance of the grouting hole area.

[0015] Compared with the prior art, the outstanding advantages and beneficial effects of the present invention are as follows: This invention roughens the steel pipe, forming uniformly dotted / microburred external teeth with a height similar to the thickness of the carbon fiber layer. This ensures close mechanical engagement with the carbon fiber without affecting the adhesion of the frosted fiber layer. The carbon fiber layer not only isolates corrosive media but also enhances the structural compressive strength and ductility through lateral restraint. The frosted fiber layer strengthens interfacial bonding, balancing durability and load-bearing efficiency. The steel pipe concrete and carbon fiber layer complement each other, avoiding the defects of materials working alone, resulting in a significant leap in overall load-bearing capacity. It has wide environmental adaptability, can withstand harsh conditions such as strong corrosion and repeated high stress, and is suitable for various complex geological and engineering environments, reducing subsequent maintenance costs. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] Figure 1 This is a schematic diagram of the steel-concrete arch frame connection of the system of the present invention; Figure 2 This is a schematic diagram of the combination of the resistance-increasing external toothed steel pipe, the connecting nut, and the reinforcing plate of the present invention; Figure 3 This is a schematic diagram of the end face of the friction-increasing external toothed steel pipe combined with the connecting nut and reinforcing plate of the present invention; Figure 4 This is a schematic diagram of the connecting nut of the present invention; Figure 5 This is a schematic diagram of the frosted fiber layer of the present invention; Figure 6 This is a schematic diagram of the sleeve connection of the present invention; Figure 7 This is a schematic diagram of the friction-enhancing external toothed steel pipe of the present invention; Figure 8 This is a schematic diagram of the vertical connection between the resistance-enhancing external toothed steel pipe and the sleeve of the present invention; Figure 9 This is a schematic diagram of the longitudinal connection of the steel arch frame of the present invention; In the diagram: 1. Surrounding rock, 2. Casing, 3. Longitudinal connecting steel bar, 4. Steel arch frame, 5. Vent hole, 6. Grouting hole, 7. Reinforcing plate, 8. Connecting nut, 9. Resistance-increasing external toothed steel pipe, 10. Carbon fiber layer, 11. Frosted fiber layer, 12. Quartz sand, 13. Basalt fiber filament, 14. Pin, 15. Grouting stop ring, 16. Nut fixing hole; Detailed Implementation It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0018] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. For ease of description, the words "up," "down," "left," and "right" appearing in this invention only indicate that they are consistent with the up, down, left, and right directions of the accompanying drawings themselves, and do not limit the structure. They are merely for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0019] As described in the background section, there are shortcomings in the existing technology. In order to solve the above-mentioned technical problems, this invention proposes a carbon fiber composite reinforced steel pipe concrete support system and construction method.

[0020] In a typical embodiment of the present invention, such as Figure 1 As shown, this embodiment provides a carbon fiber composite reinforced steel pipe concrete support system and construction method; through the corrosion protection and reinforcement of the carbon fiber layer, the interface resistance increase of the frosted fiber layer, the connection of the sleeve 2, and the connection of the rebar connector, the integrated effect of corrosion protection, interface strengthening and load-bearing capacity enhancement is achieved, thereby improving the durability, integrity and adaptability of the support structure to complex environments.

[0021] This embodiment proposes a carbon fiber composite reinforced steel-concrete composite support system, comprising a resistance-enhancing toothed steel pipe 9, a carbon fiber layer 10, a frosted fiber layer 11, a sleeve 2, longitudinal connecting steel bars 3, connecting nuts 8, grouting holes 6, and venting holes 5; wherein, the resistance-enhancing toothed steel pipe 9 is the core load-bearing component, forming a combination of excellent compressive strength and high stiffness with the internal filling concrete; furthermore, as... Figure 5 As shown, the outer side of the friction-enhancing external toothed steel pipe 9 is provided with a frosted fiber layer 11 and a carbon fiber layer 10 from the inside to the outside. The carbon fiber layer 10 can significantly strengthen the steel pipe concrete, effectively improve the overall load-bearing capacity and ductility of the structure, and at the same time have excellent corrosion resistance and fatigue resistance.

[0022] Furthermore, the frosted fiber layer 11 is composed of quartz sand 12 and basalt fiber filaments 13, which can effectively reduce the rebound of shotcrete and improve the construction effect. The basalt fiber filaments 13 and quartz sand 12 on its surface can greatly enhance the bonding force between the steel pipe concrete support and the shotcrete interface, avoid the peeling of the support interface, and improve the overall structure and stress transmission efficiency.

[0023] Furthermore, such as Figure 7 , Figure 8 As shown, the friction-enhancing external toothed steel pipe 9 is provided with grouting holes 6 and venting holes 5. The grouting holes 6 are used to inject high-strength concrete, and the venting holes 5 are used to expel air to ensure a tight filling. In this embodiment, as... Figure 2 As shown, the grouting hole 6 is located near the lower end of the resistance-enhancing external toothed steel pipe 9, and the vent hole 5 is located near the upper end of the resistance-enhancing external toothed steel pipe 9. During the grouting process through the grouting hole 6 into the resistance-enhancing external toothed steel pipe 9, the air in the resistance-enhancing external toothed steel pipe 9 is discharged through the vent hole 5, and from... Figure 3 As can be seen from the end view, the radius of the grouting hole 6 is larger than the radius of the vent hole 5.

[0024] Furthermore, a connecting nut 8 is also provided on the side of the aforementioned resistance-enhancing external toothed steel pipe 9, and the longitudinal connecting steel bar 3 is connected to the connecting nut 8 to form a continuous force transmission system; in this embodiment, as... Figure 7 , Figure 8 , Figure 9 As shown, four connecting nuts 8 are respectively provided on two opposite sides of the resistance-increasing external toothed steel pipe 9. Along the longitudinal direction of the surrounding rock 1, the longitudinal connecting steel bar 3 is connected to the connecting nuts 8 on different resistance-increasing external toothed steel pipes 9.

[0025] Furthermore, when subjected to loads, the carbon fiber layer suppresses the expansion and deformation of the steel tube through lateral restraint, thereby improving compressive strength. The steel tube concrete provides rigid support for the carbon fiber layer to avoid local instability, and the two complement each other.

[0026] Furthermore, such as Figure 6 As shown, the aforementioned resistance-enhancing external toothed steel pipe 9 comprises multiple sections, which are connected to each other by sleeves 2 and pins 14 to form a shape that matches the surrounding rock.

[0027] Furthermore, a reinforcing plate 7 is welded around the circumference of the external toothed steel pipe 9 at the locations of the grouting hole 6 and the vent hole 5.

[0028] Furthermore, a carbon fiber layer 10 is wound around the outside of the sleeve 2 and the reinforcing plate 7.

[0029] Furthermore, a grout-stopping ring is provided at the mating position of the adjacent longitudinal connecting steel bar 3 and the resistance-increasing external toothed steel pipe 9, i.e., at the position of the connecting nut 8, to prevent grout from flowing out of the hole.

[0030] Furthermore, grout-stopping rings are provided at the edge of the sleeve 2 and at the pin hole to prevent grout from flowing out of the hole.

[0031] Furthermore, the specific construction methods for the aforementioned carbon fiber reinforced concrete tubular support system are as follows: (1) Steel arch frame 4 processing The resistance-increasing external toothed steel pipe 9 is pre-processed. Reinforcing plates 7 are welded above and below the sleeve 2. The reinforcing plates 7 are welded to the resistance-increasing external toothed steel pipe 9. A grout-stopping ring 15 is attached inside the sleeve 2 to prevent leakage during grouting. The steel pipe is roughened to form uniform pits / microburrs on the resistance-increasing external teeth. The height is similar to the thickness of the carbon fiber layer to ensure close mechanical interlocking with the carbon fiber and not affect the adhesion of the frosted fiber layer. Grouting holes 6, venting holes 5, and nut fixing holes 16 are opened at the designed positions.

[0032] (2) Attach carbon fiber and screw in the connecting nut Epoxy adhesive is applied to the outside of the friction-enhancing external toothed steel pipe 9 to bond the carbon fiber layer 10. The layer is then compacted, smoothed, and tapped to ensure a closer mechanical engagement between the friction-enhancing external teeth and the carbon fiber layer 10, preventing voids and damage. Epoxy adhesive is then applied again to bond the quartz sand 12 and basalt fiber filaments 13, forming a frosted fiber layer 11. This frosted fiber layer 11 increases interfacial friction, reducing rebound of the subsequent shotcrete. Simultaneously, the basalt fiber filaments 13 bond with the shotcrete, enhancing interfacial adhesion and preventing structural interface detachment under stress. Finally, connecting nuts 8 are screwed into the nut fixing holes 16 to compact the edges of the bonded carbon fiber layer, improving its bonding effect.

[0033] (3) Tunnel excavation The tunnel section excavation was carried out in strict accordance with the underground engineering construction specifications. The surface of the surrounding rock 1 was thoroughly cleaned of floating debris and dangerous rocks, and the rock wall contour was carefully trimmed to ensure that there were no loose blocks or weak interlayers on the surface of the surrounding rock 1, so as to create a stable and safe working foundation for the subsequent support structure construction.

[0034] (4) Installation of steel arch frame 4 The external toothed steel pipes 9 of the same steel arch frame 4 are connected by sleeves 2 (see Figure 6 Then, the sleeve 2 and the resistance-increasing external toothed steel pipe 9 are fixed with pins 14. The prefabricated steel arch frame 4 is hoisted to the design position using lifting equipment and fixed with temporary supports to ensure connection accuracy.

[0035] (5) Installation of longitudinal reinforcement bars Tighten the longitudinal connecting steel bar 3 into the connecting nut 8, straighten and fix it to form a longitudinal force transmission skeleton, and improve the overall rigidity and deformation resistance of the support system.

[0036] (6) Grouting and filling High-strength concrete is injected into the inner cavity of the steel pipe under high pressure through the grouting hole 6. During the grouting process, trapped air is discharged through the vent hole 5 to ensure that the concrete is filled densely without voids. After the grouting is completed, it is cured according to the specifications until the concrete reaches the design strength.

[0037] (7) Grouting hole sealing and reinforcement After the grouting concrete inside the friction-enhancing external toothed steel pipe 9 reaches its initial setting strength, thoroughly clean the laitance and debris from the surface of the steel pipe outside the grouting hole 6 and the vent hole 5. Use steel plates to seal the grouting hole 6 and the vent hole 5 to ensure a tight seal. Then, use epoxy adhesive to wrap carbon fiber cloth in a ring around the outside of the grouting hole 6 and the vent hole 5 and the surrounding steel pipe surface, and compact and smooth the carbon fiber cloth to ensure that it fits tightly with the friction-enhancing external toothed steel pipe 9, the grouting hole 6, and the vent hole 5 without any voids, which significantly enhances the structural integrity and crack resistance of the grouting hole area.

[0038] (8) Shotcrete After the concrete inside the steel pipe reaches the required strength and all connection nodes and protective layers pass inspection, concrete is sprayed onto the entire cross-section of the tunnel surrounding rock, the outer side of the steel arch frame 4, and the surface of the frosted fiber layer to ensure complete coverage without omission, forming a composite support structure of "surrounding rock-sprayed concrete-carbon fiber reinforced steel pipe concrete" working together to further improve overall stability and deformation resistance.

[0039] The carbon fiber layer of this invention not only isolates corrosive media but also enhances the structural compressive strength and ductility through lateral restraint. The frosted fiber layer strengthens interfacial bonding, balancing durability and load-bearing efficiency. The steel-concrete composite and carbon fiber layer complement each other, avoiding the defects of materials working alone, and significantly increasing the overall load-bearing capacity. It has wide environmental adaptability, can withstand harsh working conditions such as strong corrosion and repeated high stress, and is suitable for various complex geological and engineering environments, reducing later maintenance costs.

[0040] Finally, it should be noted that relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A carbon fiber composite reinforced steel-concrete composite support system, characterized in that, It includes a resistance-enhancing external toothed steel pipe, a carbon fiber layer, a frosted fiber layer, and longitudinal connecting steel bars; Several resistance-increasing toothed steel pipes are installed along the longitudinal direction of the surrounding rock for supporting the surrounding rock. The inside of the resistance-increasing toothed steel pipes is filled with concrete, and a carbon fiber layer is pasted on the outside of the steel pipe body. The resistance-increasing teeth and the carbon fiber layer are mechanically interlocked. A frosted fiber layer is pasted on the outside of the carbon fiber layer. Longitudinal connecting steel bars pass through several steel pipe bodies along the longitudinal direction of the surrounding rock to realize the connection between the steel pipe bodies.

2. The carbon fiber composite reinforced steel-concrete composite support system as described in claim 1, characterized in that, The abrasive fiber layer is composed of quartz sand and fiber filaments.

3. The carbon fiber composite reinforced steel-concrete composite support system as described in claim 1, characterized in that, The aforementioned resistance-enhancing external toothed steel pipe is provided with grouting holes and venting holes. The grouting holes are used to inject high-strength concrete, and the venting holes are used to expel air to ensure a dense filling.

4. The carbon fiber composite reinforced steel-concrete composite support system as described in claim 1, characterized in that, A nut fixing hole is also provided on the side of the aforementioned resistance-increasing external toothed steel pipe. A nut is fixed in the nut fixing hole, and the nut is connected to the longitudinal connecting steel bar to form a continuous force transmission system.

5. The carbon fiber composite reinforced steel-concrete composite support system as described in claim 1, characterized in that, The aforementioned resistance-enhancing external toothed steel pipe comprises multiple sections, which are connected to each other by sleeves and pins to form a shape that matches the surrounding rock; the sleeve is wrapped with a carbon fiber reinforcement layer.

6. The carbon fiber composite reinforced steel-concrete composite support system as described in claim 1, characterized in that, A reinforcing plate is welded around the circumference of the external toothed steel pipe at the locations of the grouting hole and vent hole.

7. A construction method for a carbon fiber composite reinforced steel-concrete composite support system as described in any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Pre-process the resistance-increasing external toothed steel pipe. The resistance-increasing external toothed steel pipe is opened with grouting holes, venting holes and nut fixing holes according to the design position; and a grout-stopping ring is attached inside the connecting sleeve. Step 2: Apply epoxy adhesive to the outside of the resistance-enhancing external toothed steel pipe to bond the carbon fiber layer, compact and smooth it, and tap it to make the mechanical engagement between the resistance-enhancing external teeth and the carbon fiber layer closer, ensuring no hollow areas or damage; apply epoxy adhesive again to bond the quartz sand and basalt fiber filaments to form a frosted fiber layer; screw the connecting nut into the nut fixing hole to compact the edge of the bonded carbon fiber layer and improve the bonding effect of the carbon fiber layer; Step 3: Tunnel excavation; Step 4: The external toothed steel pipes of the same steel arch frame are connected by sleeves and fixed with pins. The prefabricated steel arch frame is hoisted to the design position and fixed with temporary supports. Step 5: Install longitudinal reinforcing bars; Step 6: High-strength concrete is injected into the inner cavity of the steel pipe under high pressure through the grouting hole. During the grouting process, trapped air is discharged through the vent hole to ensure that the concrete is filled densely without voids. After the grouting is completed, it is cured according to the specifications until the concrete reaches the design strength. Step 7: Grouting hole sealing and reinforcement; Step 8: After the concrete inside the steel pipe reaches the required strength and all connection nodes and protective layers pass inspection, spray concrete onto the entire cross-section of the tunnel surrounding rock, the outer side of the steel arch frame, and the surface of the frosted fiber layer to ensure complete coverage without omission, forming a composite support structure in which the surrounding rock, sprayed concrete, and carbon fiber reinforced steel pipe concrete work together to further improve the overall stability and deformation resistance.

8. The construction method of the carbon fiber composite reinforced steel pipe concrete support system as described in claim 7, characterized in that, The processing method for the resistance-enhancing external toothed steel pipe in step 1 is as follows: The steel pipe is roughened to form uniform pits / microburrs that increase resistance. The height of these teeth is similar to the thickness of the carbon fiber layer, ensuring close mechanical engagement with the carbon fiber without affecting the adhesion of the frosted fiber layer.

9. A construction method for a carbon fiber composite reinforced steel-concrete composite support system as described in claim 7, characterized in that, In step 5, the longitudinal connecting steel bars are screwed into the connecting nuts, straightened and fixed to form a longitudinal force transmission skeleton, thereby improving the overall rigidity and deformation resistance of the support system.

10. A construction method for a carbon fiber composite reinforced steel-concrete composite support system as described in claim 7, characterized in that, In step 7, after the grouting concrete inside the friction-enhancing external toothed steel pipe reaches its initial setting strength, the laitance and debris on the surface of the steel pipe outside the grouting hole and vent hole are thoroughly cleaned. The grouting hole and vent hole are sealed with steel plates to ensure a tight seal. Then, carbon fiber cloth is wrapped in a ring around the outside of the grouting hole and vent hole and the surrounding steel pipe surface with epoxy adhesive. The carbon fiber cloth is compacted and smoothed to ensure that it is tightly attached to the steel pipe, grouting hole and vent hole without voids, which significantly enhances the structural integrity and crack resistance of the grouting hole area.

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