CN108824230B - A method of strengthening bridge underwater piers with FRP pipes - Google Patents

Abstract

A method for reinforcing an underwater bridge pier by using an FRP pipe comprises the steps of installing a positioning piece, wrapping a steel wire mesh, manufacturing a self-locking type FRP pipe, winding the self-locking type FRP pipe, solidifying a connecting part of the self-locking type FRP pipe, activating a bottom seal and pouring filling materials to realize the reinforcement of the underwater bridge pier, fastening the self-locking type FRP pipe by a movable clamp of the self-locking type FRP pipe, injecting an underwater adhesive into a glue injection cavity of the movable clamp to enable the self-locking type FRP pipe to be bonded into a whole, and injecting the filling materials into a gap formed between the self-locking type FRP pipe and the bridge pier to be reinforced to finish the reinforcement of the underwater bridge pier. The self-locking FRP pipe is simple in process, one-time fastening is achieved, no binding belt is needed, construction procedures are reduced, corrosion resistance is good, cofferdam and templates are not needed, labor intensity of workers is reduced, the self-locking FRP pipe can be directly reinforced under water, influence on a channel is reduced, applicability is wide, and construction is rapid and convenient.

Description

A method of strengthening bridge underwater piers with FRP pipes

Technical field

The invention relates to a method for reinforcing the underwater structure of a bridge, specifically to a method for reinforcing the underwater pier of a bridge with an FRP pipe, and belongs to the technical field of civil engineering.

Background technique

As a country with many rivers and lakes, a large number of railway bridges and road bridges connect the land transportation network. As the operating time of the bridges increases and the traffic volume increases, various problems continue to emerge. Compared with the upper structure of the bridge, the lower part Damage to underwater structures is more common and difficult to detect. Loads caused by high underwater static stress, water flow impact, ship impact, erosion, freeze-thaw cycles in severe cold areas, etc. can easily cause damage to underwater structures of bridges. Such damage as spalling of the concrete protective layer, cracks, exposed bars, corrosion of steel bars, and undercutting of the riverbed will lead to a reduction in the bridge's bearing capacity, durability, and service life, seriously endangering driving safety. Bridge piers are the main supports of the main structure of the bridge. Once the bridge is damaged during operation, it will seriously limit the performance of the bridge-related functions, and even cause the bridge to collapse due to insufficient bearing capacity.

Due to the inconvenience of large-scale regular maintenance of underwater bridge piers, diseases are often not discovered in time. When designing bridges, the safety factor of the substructure is larger and is considered a safer part. However, later safety inspections are often ignored. The disease treatment is not timely, and due to the difficulty of construction operations in the underwater environment and the specific applicability of the treatment methods, research on the reinforcement technology of underwater bridge piers is of great significance. Commonly used bridge pier reinforcement methods mainly include enlarged cross-section reinforcement method, bonded steel reinforcement method, external prestressed reinforcement method, wire winding reinforcement method, etc. These methods play a certain role in structural reinforcement in actual projects, but at the same time they also There are respective shortcomings. The construction period of the enlarged cross-section reinforcement method is long, there is a lot of wet work on site, and it has a great impact on the surrounding environment; the bonded steel reinforcement method has higher requirements for the strength of the base concrete, and the reinforcement quality depends largely on cementation. The quality of the materials and the level of construction technology; the construction technology of the external prestressed reinforcement method is complex and the prestress loss is large; the wire winding reinforcement method also has problems such as cumbersome construction technology during underwater undrained construction.

FRP (fiber reinforced composite material) has good application prospects in the field of civil engineering due to its advantages such as light weight, corrosion resistance, and easy molding. FRP tube restraint reinforced concrete can effectively improve the bearing capacity, ductility, seismic performance and durability of structural components. Based on the special properties of the material, FRP pipes are used to reinforce structures in some special environments and have good application prospects. The invention proposes a method for reinforcing underwater piers of bridges with FRP pipes. The self-locking fixation of self-locking FRP pipes is used to realize the reinforcement of underwater piers of bridges. The technology is simple, the construction is quick and convenient, and the reinforcement effect is good.

Contents of the invention

The purpose of the invention is to provide a method for reinforcing underwater bridge piers with FRP pipes. The self-locking FRP pipe is clamped by its own movable clamp and fixed with glue without the need for tie ties, which reduces the construction process and is based on the lightweight FRP material. , corrosion resistance, easy to form and other advantages. After strengthening the piers, the bearing capacity, ductility, durability and seismic performance of the structural components can be effectively improved. The construction process does not require cofferdams and large steel formwork, which reduces the labor intensity of workers. The process is simple and can Direct reinforcement underwater reduces the impact on the waterway, has wide applicability, and is fast and convenient to construct.

The technical solution of the present invention is: a method for reinforcing underwater bridge piers with FRP pipes, by installing positioning parts, wrapping steel wire mesh, making self-locking FRP pipes, winding self-locking FRP pipes, and consolidating self-locking FRP pipe connections parts, activate the bottom seal, and pour filling materials to reinforce the underwater piers of the bridge. The self-locking FRP pipe is equipped with limit pads, movable clamps, and bottom seals to facilitate the underwater assembly of the FRP pipe, and the template is combined with the bottom seal. The reinforcement materials are integrated into one body to avoid drainage work; it is characterized by the following construction steps:

A. Surface treatment of the bridge pier to be reinforced: Set up a construction platform in the construction area, and have divers clean the weak layer, attached silt and other impurities on the surface of the bridge pier to be reinforced until a solid surface is exposed;

B. Make steel wire mesh and fixed positioning parts: Make steel mesh according to the size and specification required by the design, and fix positioning parts discretely on the steel mesh. The positioning parts are located inside the steel mesh, and the thickness of the positioning parts is determined by the distance between the steel mesh and the pier to be reinforced. The size of the gap is determined, and the layout range is twice the perimeter of the bridge pier to be reinforced;

C. Wrapping steel wire mesh: Wrap more than one layer of steel wire mesh circumferentially around the pier to be reinforced according to the size required by the design. Set one side of the positioning piece to be close to the surface of the pier to be reinforced. According to the positioning of the positioning piece, the steel mesh There is a certain gap between the bridge pier and the bridge pier to be reinforced. The overlap length of the steel mesh along the circumferential direction is not less than 300mm, and steel wire buckles are used for snap connection at the overlap;

D. Production of self-locking FRP pipe: The shell of the self-locking FRP pipe is formed by laying more than one layer of fiber cloth, impregnating hand lay-up, molding or vacuum-assisted molding process. One end of the shell of the self-locking FRP pipe is the fixed end. , equipped with a movable clamp, which is composed of a glue injection cavity, a base, a pressure plate and bolts. The other end of the shell is the movable end; the inner side of the shell is discretely provided with limit pads, and its thickness is determined by the total amount of filling material. The thickness is determined, and the lower edge of the shell is provided with a bottom seal that is no less than the circumferential circumference of the pier to be reinforced, and the bottom seal is pre-wrapped with a water-proof film;

E. Winding self-locking FRP pipe: The equipment will send the prefabricated self-locking FRP pipe to the predetermined underwater location. Underwater professional staff will wrap the self-locking FRP pipe around the periphery of the steel wire mesh and wrap it. The movable end of the shell extends between the pressure plate and the base of the movable clamp at the other end, tighten the movable end of the shell, press the bottom seal and the limit pad, and the extension length is not less than 100cm;

F. Consolidated self-locking FRP pipe connection part: Underwater professional staff should tighten the bolts on the movable fixture symmetrically up and down, so that the pressure plate presses the base, fix the movable end of the anchor shell, and move it toward the gap between the pressure plate and the base. Inject underwater adhesive into the glue injection cavity for solidification, so that the shell is circumferentially bonded as a whole;

G. Activate the bottom seal: After the underwater adhesive solidifies, remove the water-proof film of the bottom seal. After the bottom seal expands when exposed to water, it will completely seal the gap between the self-locking FRP pipe and the bottom of the pier to be reinforced, forming a bottom seal. , a cavity with an open top, the thickness of the cavity is the thickness of the reinforcement layer;

H. Filling material: Use grouting equipment to press filling material into the cavity between the self-locking FRP pipe and the pier to be reinforced. The pressing process is continued and stably until the entire cavity is filled densely;

I. Completion of reinforcement: After the poured filling material reaches the specified strength, the reinforcement of the underwater piers of the bridge is completed.

The movable clamp is made of metal material. The lower end of the base is closed, the upper end is open, and notches are opened on the left and right sides. The pressing surface of the base and the pressure plate and the pressure plate are equipped with corresponding convex racks and scoring structures at the same time. Multiple score structures are located between adjacent convex racks. The pressing plate can move toward the base as the bolts are tightened. The height of the convex racks is greater than the height of the score structure. After the convex racks are pressed, A glue injection cavity is formed between adjacent convex racks between the pressure plate and the base.

The self-locking FRP pipe is composed of a shell, a limit pad, a movable clamp and a bottom seal. The fixed end of the shell is bonded and fixed with the base of the movable clamp in advance, and the movable end of the shell extends through and is fixed. Between the pressure plate and the base of the movable clamp at the end, the protruding length is not less than 100cm.

The material of the bottom seal is preferably a water-swellable material, which is pre-sealed with a water-proof film and arranged along the lower edge of the shell of the self-locking FRP pipe.

The scoring structure is preferably in the form of bidirectional scoring, pits or floating points.

The underwater adhesive is preferably underwater epoxy resin glue, polyurethane glue or cyanoacrylate glue; the positioning piece and limiting pad are one of plastics, composite materials, cement-based materials, and metal materials.

The steel wire mesh is stainless steel wire mesh or galvanized steel wire mesh; the filling material is underwater epoxy resin, underwater non-dispersible mortar, underwater epoxy resin mortar, underwater non-dispersible concrete or underwater epoxy. A kind of resin concrete.

The winding shape of the self-locking FRP pipe is either circular or polygonal.

In the structure of the present invention, the characteristics of light weight, high strength and anti-corrosion performance of FRP materials are used to make self-locking FRP pipes and steel wire mesh to wrap the underwater bridge piers together, and filling materials are poured into the gaps to achieve non-drainage To complete the repair and reinforcement of the bridge's underwater piers, the self-locking FRP pipes are connected into pipes through movable clamps. At the same time, underwater adhesive is injected into the glue injection cavity formed between the pressure plate and the base to make the self-locking FRP pipes Tightly fixed, with simple process and one-time molding, the presence of steel mesh improves the bearing capacity, stiffness and ductility of the overall structure.

The construction process of the invention does not require cofferdams and large steel formwork, reduces the labor intensity of workers, can be directly reinforced underwater, reduces the impact on waterways, has wide applicability, and is fast and convenient to construct. The invention has the following beneficial effects:

(1) The self-locking FRP pipe comes with a movable clamp. The movable clamp clamps shells of any thickness. It has a wide range of applications and does not require pre-fixing with outer ties. The underwater adhesive in the pressure plate and glue injection cavity is in place at one time, and double tightening is required. Solid, excellent reinforcement effect.

(2) The self-locking FRP pipe material has excellent properties such as light weight, high strength, and corrosion resistance. It also eliminates the need for large steel formwork and can be directly used as an outer formwork when pouring filling materials, and there is no need to consider the turnover of the formwork. problem, greatly shortening the construction period and saving costs.

(3) The bottom seal is made of water-swellable material and is pre-wrapped with a water-proof film. After the self-locking FRP pipe is fixed and activated before filling the filling material, it realizes the function of timed sealing and water-stopping, which can prevent pre-expansion from damaging the reinforcement layer. Effect of thickness.

(4) The construction process is simple and does not require the erection of large-scale construction platforms and cofferdams. Underwater reinforcement without drainage is achieved. The construction process has little impact on the waterway, ensuring the progress of the entire project.

(5) Effectively improve the bearing capacity, corrosion resistance, ductility and seismic performance of the bridge pier to be underwater, with wide applicability, and the materials used are suitable for underwater environments.

Picture description:

Figure 1 is an anatomical structural diagram of a method of reinforcing underwater bridge piers with FRP pipes;

Figure 2 is a process flow chart of a method for reinforcing underwater bridge piers with FRP pipes;

Figure 3 is a three-dimensional schematic view of the steel wire mesh with positioning parts installed;

Figure 4 is a schematic elevation view of the underwater wrapped steel mesh;

Figure 5 is a schematic structural perspective view of a self-locking FRP pipe with a bottom seal installed;

Figure 6 is a schematic structural elevation view of a self-locking FRP pipe that is wound and fixed with glue;

Figure 7 is a schematic structural elevation view of the activated bottom seal;

Figure 8 is a schematic structural elevation view of the filling material filling process;

Figure 9 is a schematic elevation view of the underwater pier of the bridge after completion of reinforcement;

Figure 10 is a partially enlarged structural diagram of the movable clamp A in Figure 5;

Figure 11 is a partially enlarged structural diagram of the movable clamp-consolidated self-locking FRP pipe B in Figure 9;

Figure 12 is a schematic diagram of the circular cross-section of the reinforced underwater bridge pier;

Figure 13 is a schematic diagram of the rectangular cross-section of the reinforced underwater pier of the bridge;

In all the drawings, 1 is the self-locking FRP pipe; 11 is the shell; 12 is the limit pad; 2 is the movable clamp; 21 is the base; 22 is the pressure plate; 23 is the bolt; 20 is the glue injection cavity ; 201 is the convex rack; 202 is the scoring structure; 3 is the steel mesh; 31 is the positioning piece; 4 is the bottom seal; 5 is the pier to be reinforced; 6 is the filling material; 7 is the underwater adhesive.

Detailed ways:

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention will now be described with reference to the accompanying drawings. The invention provides a method for reinforcing underwater bridge piers with FRP pipes, by installing positioning parts 31, wrapping steel wire mesh 3, making self-locking FRP pipes 1, winding self-locking FRP pipes 1, and consolidating self-locking FRP pipes 1 At the connection part, activate the bottom seal 4 and pour filling material 6 to reinforce the bridge's underwater piers. The self-locking FRP pipe 1 is equipped with a limit pad 12, a movable clamp 2 and a bottom seal 4 to realize the underwater sealing of the FRP pipe. It is easy to assemble, and the formwork and reinforcement materials are integrated to avoid drainage work; it is characterized by the following construction steps:

A. Surface treatment of the bridge pier to be reinforced: Set up a construction platform in the construction area, and have divers clean the weak layer, attached silt and other impurities on the surface of the bridge pier 5 to be reinforced until a solid surface is exposed;

B. Make the steel wire mesh and fixed positioning parts: Make the steel wire mesh 3 according to the size and specification required by the design, and fix the positioning parts 31 discretely on the steel wire mesh 3. The positioning parts 31 are located inside the steel wire mesh 3. The thickness of the positioning parts 31 is determined by the steel wire. The size of the gap between the net 3 and the pier 5 to be reinforced is determined, and the layout range is twice the circumference range of the pier 5 to be reinforced;

C. Wrapping steel wire mesh: According to the size required by the design, wrap more than one layer of steel wire mesh 3 circumferentially around the pier 5 to be reinforced underwater, and set one side of the positioning member 31 so that the inside is close to the surface of the pier 5 to be reinforced. According to the positioning member 31 Positioning, there is a certain gap between the steel mesh 3 and the pier 5 to be reinforced, the overlap length of the steel mesh 3 along the circumferential direction is not less than 300mm, and the overlap is connected with a steel wire buckle;

D. Make the self-locking FRP pipe: The shell 11 of the self-locking FRP pipe 1 is formed by laying more than one layer of fiber cloth and impregnating hand lay-up, molding or vacuum-assisted molding process. One end is a fixed end and is provided with a movable clamp 2. The movable clamp 2 is composed of a glue injection cavity 20, a base 21, a pressure plate 22 and a bolt 23. The other end of the housing 11 is a movable end; the inner side of the housing 11 is provided with discrete limits. The thickness of the cushion block 12 is determined by the total thickness of the filling material 6. The lower edge of the shell 11 is provided with a bottom seal 4 that is not less than the circumferential circumference of the pier 5 to be reinforced. The bottom seal 4 is pre-made with a water-proof film. pack;

E. Winding self-locking FRP pipe: The equipment will send the prefabricated self-locking FRP pipe 1 to a predetermined underwater location, and underwater professional staff will wrap the self-locking FRP pipe 1 around the periphery of the steel wire mesh 3. Insert the movable end of the wrapped casing 11 between the pressure plate 22 and the base 21 of the movable clamp 2 at the other end, tighten the movable end of the casing 11, and press the bottom seal 4 and the limit pad 12 , and the extended length is not less than 100cm;

F. Consolidated self-locking FRP pipe connection part: The underwater professional staff tightens the bolts 23 on the movable fixture 2 symmetrically up and down, so that the pressure plate 22 presses the base 21 tightly, fixes the movable end of the anchor shell 11, and moves it toward the pressure plate 22 The underwater adhesive 7 is injected into the glue injection cavity 20 between the base 21 and the base 21 for solidification, so that the shell 11 is circumferentially bonded as a whole;

G. Activate the bottom seal: After the underwater adhesive 7 solidifies, remove the water-proof film of the bottom seal 4. After the bottom seal 4 expands when exposed to water, the gap at the bottom of the self-locking FRP pipe 1 and the pier 5 to be reinforced will be completely closed. , forming a cavity with a bottom seal and an open top, and the thickness of the cavity is the thickness of the reinforcement layer;

H. Filling material: Use the grouting equipment to press the filling material 6 into the cavity between the self-locking FRP pipe 1 and the pier 5 to be reinforced. The pressing process is continued and stably until the entire cavity is filled. until dense;

I. Completion of reinforcement: After the filling material 6 to be poured reaches the specified strength, the reinforcement of the underwater piers of the bridge is completed.

The movable clamp 2 is made of metal material. The lower end of the base 21 is closed, the upper end is open, and notches are provided on the left and right sides. The pressing surface of the base 21 and the pressure plate 22 and the pressure plate 22 are provided with corresponding convex racks at the same time. 201 and score structure 202. Multiple score structures 202 are located between adjacent convex racks 201. The pressure plate 22 can move toward the base 21 and press together as the bolt 23 is twisted. The height of the convex rack 201 is larger than the score After the convex racks 201 are pressed together, a glue injection cavity 20 is formed between the adjacent convex racks 201 between the pressure plate 22 and the base 21 .

The self-locking FRP pipe 1 is composed of a shell 11, a limit pad 12, a movable clamp 2 and a bottom seal 4. The fixed end of the shell 11 is bonded and fixed with the base 21 of the movable clamp 2 in advance. The movable end of the body 11 penetrates between the pressure plate 22 and the base 21 of the movable clamp 2 extending into the fixed end, and the extended length is not less than 100cm.

The material of the bottom seal 4 is preferably a water-swellable material, which is pre-sealed with a water-proof film and is arranged along the lower edge of the shell 11 of the self-locking FRP pipe 1 .

The score structure 202 is preferably in the form of bidirectional scores, pits or floating points.

The underwater adhesive 7 is preferably underwater epoxy resin glue, polyurethane glue or cyanoacrylate glue; the positioning piece 31 and the limiting pad 12 are made of plastic, composite materials, cement-based materials, or metal materials. A sort of.

The steel wire mesh 3 is stainless steel wire mesh 3 or galvanized steel wire mesh 3; the filling material 6 is underwater epoxy resin, underwater non-dispersible mortar, underwater epoxy resin mortar, underwater non-dispersible concrete or A type of underwater epoxy resin concrete.

The winding shape of the self-locking FRP pipe 1 is either circular or polygonal.

Claims (6)

1. A method for reinforcing underwater bridge piers with FRP pipes by installing positioning pieces, wrapping steel wire mesh, making self-locking FRP pipes, winding self-locking FRP pipes, consolidating self-locking FRP pipe connection parts, and activating the bottom end Sealing and pouring filling materials realize the reinforcement of the bridge's underwater piers. The self-locking FRP pipe is equipped with limit pads, movable clamps and bottom seals to realize the convenient underwater assembly of the FRP pipe, and integrate the formwork and reinforcement materials into one , to avoid drainage work; it is characterized by the following construction steps: A. Surface treatment of the bridge pier to be reinforced: Divers will clean the weak layer, attached silt and other impurities on the surface of the bridge pier (5) to be reinforced until a solid surface is exposed; B. Make the steel wire mesh and fixed positioning parts: Make the steel wire mesh (3) according to the size and specification required by the design, fix the positioning parts (31) discretely on the steel wire mesh (3), and the positioning parts (31) are located on the steel wire mesh (3) Inside, the thickness of its positioning piece (31) is determined by the size of the gap between the steel mesh (3) and the pier (5) to be reinforced, and the layout range is twice the circumference of the pier (5) to be reinforced; C. Wrap steel wire mesh: Wrap more than one layer of steel wire mesh (3) around the pier (5) to be reinforced underwater, and set the side of the positioning member (31) so that the inside is close to the surface of the pier (5) to be reinforced. According to When positioning the positioning piece (31), there is a certain gap between the steel mesh (3) and the pier (5) to be reinforced. The overlap length of the steel mesh (3) along the circumferential direction is not less than 300mm, and a steel wire buckle is used to clamp the overlap. buckle connection; D. Make the self-locking FRP pipe: The shell (11) of the self-locking FRP pipe (1) is formed by laying more than one layer of fiber cloth with impregnated hand lay-up, molding or vacuum-assisted molding process. The self-locking FRP pipe (1) ) of the housing (11) is a fixed end and is provided with a movable clamp (2). The movable clamp (2) consists of a glue injection cavity (20), a base (21), a pressure plate (22) and a bolt (23) The other end of the shell (11) is the movable end; the inner side of the shell (11) is discretely provided with limit pads (12), the thickness of which is determined by the total thickness of the filling material (6). The shell (11) The lower edge is provided with a bottom seal (4) that is not less than the circumferential circumference of the pier (5) to be reinforced. The bottom seal (4) is pre-wrapped with a water-proof film; the movable clamp (2) is made of metal material, and the base The lower end of (21) is closed, the upper end is open, and notches are opened on the left and right sides. The pressing surface of the base (21) and the pressure plate (22) and the pressure plate (22) are simultaneously provided with corresponding convex racks (201) and engravings. The multiple score structures (202) are located between adjacent convex racks (201), and the pressure plate (22) can move toward the base (21) and press together as the bolt (23) is twisted. , the height of the convex rack (201) is greater than the height of the score structure (202). After the convex rack (201) is pressed, the adjacent convex rack (201) between the pressure plate (22) and the base (21) 201) to form a glue injection cavity (20); E. Wrap the self-locking FRP pipe: Wrap the self-locking FRP pipe (1) around the periphery of the steel mesh (3), and insert the movable end of the wrapped shell (11) into the movable clamp (11) at the other end. 2) Between the pressure plate (22) and the base (21), tighten the movable end of the housing (11), press the bottom seal (4) and the limit pad (12); self-locking FRP pipe ( 1) It consists of a shell (11), a limit pad (12), a movable clamp (2) and a bottom seal (4). The fixed end of the shell (11) is connected to the base (2) of the movable clamp (2) in advance. 21) Bonding and fixation, the movable end of the housing (11) penetrates between the pressure plate (22) and the base (21) of the movable clamp (2) extending into the fixed end, and the extended length is not less than 100cm; F. Consolidate the self-locking FRP pipe connection part: symmetrically tighten the bolts (23) on the movable clamp (2), so that the pressure plate (22) presses the base (21), and fixes the movable end of the anchor shell (11). Inject underwater adhesive (7) into the glue injection cavity (20) between the pressure plate (22) and the base (21) for solidification, so that the shell (11) is circumferentially bonded as a whole; G. Activate the bottom seal: After the underwater adhesive (7) solidifies, remove the water-proof film of the bottom seal (4). After the bottom seal (4) expands when exposed to water, connect the self-locking FRP pipe (1) and the waiting seal. The gap at the bottom of the reinforced pier (5) is completely closed, forming a cavity with a sealed bottom and an open top; H. Filling material: Use the grouting equipment to press the filling material (6) into the cavity between the self-locking FRP pipe (1) and the pier to be reinforced (5) until the entire cavity is filled densely; I. Completion of reinforcement: After the filling material (6) to be poured reaches the specified strength, the reinforcement of the underwater piers of the bridge is completed. 2. A method of reinforcing underwater piers of bridges with FRP pipes as claimed in claim 1, characterized in that the material of the bottom seal (4) is preferably a water-swellable material, which is pre-sealed with a water-proof film. It is arranged along the lower edge of the shell (11) of the self-locking FRP pipe (1). 3. A method of reinforcing underwater bridge piers with FRP pipes as claimed in claim 2, characterized in that the score structure (202) is preferably in the form of bidirectional scores, pits or floating points. 4. A method for reinforcing underwater bridge piers with FRP pipes as claimed in claim 1, characterized in that the underwater adhesive (7) is preferably underwater epoxy resin glue, polyurethane glue or cyanoacrylate glue. ; The positioning piece (31) and the limiting pad (12) are made of plastic, composite material, cement-based material, or metal material. 5. A method of reinforcing underwater piers of bridges with FRP pipes as claimed in claim 1, characterized in that the steel wire mesh (3) is stainless steel wire mesh or galvanized steel wire mesh; the filling material (6) It is one of underwater epoxy resin, underwater non-dispersible mortar, underwater epoxy resin mortar, underwater non-dispersible concrete or underwater epoxy resin concrete. 6. A method of reinforcing underwater bridge piers with FRP pipes according to claim 1, characterized in that the winding shape of the self-locking FRP pipe (1) is one of a circle or a polygon.