High-adhesion self-monitoring FRP pipe concrete composite pile and manufacturing method thereof

Abstract

The invention discloses a high-adhesion self-monitoring FRP pipe concrete composite pile and a manufacturing method thereof, and relates to the technical field of civil engineering, the high-adhesion self-monitoring FRP pipe concrete composite pile comprises an FRP outer pipe, an FRP middle pipe, an FRP inner pipe and core concrete, and the core concrete, the FRP inner pipe and the FRP middle pipe are all arranged in the FRP outer pipe. The FRP outer pipe comprises an outer pipe FRP rib, an outer pipe FRP contact wall surface and an outer pipe FRP pipe body from inside to outside; the FRP inner pipe comprises an inner pipe FRP pipe body, an inner pipe FRP contact wall surface and an inner pipe FRP rib from inside to outside; the FRP middle pipe comprises a middle pipe inner side FRP rib, a middle pipe inner side FRP contact wall surface, a middle pipe FRP pipe body, a middle pipe outer side FRP contact wall surface and a middle pipe outer side FRP rib from inside to outside, the outer surface of the FRP outer pipe is subjected to sand burning treatment, and distributed optical fiber sensing optical cables are arranged in the FRP pipe body. According to the high-adhesion self-monitoring FRP pipe concrete composite pile and the manufacturing method thereof, the adhesion performance of an FRP pipe-concrete interface and an FRP pipe-soil body interface in an existing FRP pipe concrete composite pile is improved, and meanwhile real-time monitoring of the service performance of the composite pile is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of civil engineering, and in particular to a high-bond self-monitoring FRP pipe concrete composite pile and a manufacturing method thereof. BACKGROUND

[0002] Fiber-reinforced composite materials (FRP) can be produced using recycled plastics and natural fibers, and have the characteristics of low carbon emissions, low unit strength cost, high specific strength and specific modulus, and excellent corrosion resistance. The FRP pipe concrete composite pile made by wrapping an FRP pipe and pouring concrete inside can significantly improve the corrosion resistance of the pile foundation and reduce the carbon emissions in the whole life cycle. However, the existing FRP pipe concrete composite pile has the following two problems:

[0003] Firstly, the surface of the FRP pipe is relatively smooth, and the bonding performance of the FRP pipe-concrete interface is poor, which makes it difficult for the FRP pipe and the core concrete to work together. At the same time, the bonding strength of the FRP pipe-soil interface is low, which leads to poor load transfer capacity of the FRP pipe concrete composite pile and soil, thereby limiting the bearing capacity of the FRP pipe concrete composite pile.

[0004] Secondly, since the pile foundation is deeply buried underground, it is difficult to learn about the damage state of the pile foundation through daily inspection. The existing FRP pipe concrete composite pile does not solve the problem that the performance degradation process of the pile foundation during service is difficult to monitor in real time, and the failure process is not easy to timely warn, and cannot fundamentally guarantee the safety of the structure in use. SUMMARY

[0005] The purpose of the present application is to provide a high-bond self-monitoring FRP pipe concrete composite pile and a manufacturing method thereof, to improve the bonding performance of the FRP pipe-concrete interface and the FRP pipe-soil interface in the existing FRP pipe concrete composite pile, and to realize real-time monitoring of the performance of the composite pile during service, thereby solving the problems of relatively low bearing capacity of the existing FRP pipe concrete composite pile and difficulty in timely evaluation of the service state during long-term service and effective early warning of the failure process.

[0006] To achieve the above-mentioned purpose, the present application provides a high-bond self-monitoring FRP pipe concrete composite pile, which comprises an FRP outer pipe, an FRP middle pipe, an FRP inner pipe and a core concrete, the core concrete, the FRP inner pipe and the FRP middle pipe are all arranged inside the FRP outer pipe; the FRP outer pipe comprises, from inside to outside, an outer pipe FRP rib, an outer pipe FRP contact wall surface and an outer pipe FRP pipe body; the FRP inner pipe comprises, from inside to outside, an inner pipe FRP pipe body, an inner pipe FRP contact wall surface and an inner pipe FRP rib; the FRP middle pipe comprises, from inside to outside, a middle pipe inner side FRP rib, a middle pipe inner side FRP contact wall surface, a middle pipe FRP pipe body, a middle pipe outer side FRP contact wall surface and a middle pipe outer side FRP rib.

[0007] Preferably, the outer tube FRP pipe body, the inner tube FRP pipe body and the middle tube FRP pipe body each comprise a plurality of longitudinal fiber layers, a plurality of oblique fiber layers and a distributed optical fiber sensing optical cable, the distributed optical fiber sensing optical cable is laid in the longitudinal fiber layer along the longitudinal direction, and the fiber direction of the oblique fiber layer is an angle (75°, 90°] with the longitudinal direction of the outer tube FRP pipe body.

[0008] Preferably, the outer tube FRP contact wall surface and the inner tube FRP contact wall surface are each provided with a plurality of oblique fiber layers with the same fiber direction, and the outer surface of the outer tube FRP contact wall surface and the inner surface of the inner tube FRP contact wall surface are respectively attached with an outer tube FRP rib and an inner tube FRP rib, and the fiber directions of the inner tube FRP rib and the outer tube FRP rib are respectively the same as the fiber directions of the inner tube FRP contact wall surface and the outer tube FRP contact wall surface.

[0009] Preferably, the inner side FRP contact wall surface of the middle tube and the outer side FRP contact wall surface of the middle tube each comprise a plurality of oblique fiber layers with the same fiber direction, and the inner side FRP contact wall surface of the middle tube and the outer side FRP contact wall surface of the middle tube are each attached with a FRP rib, and the fiber directions of the inner side FRP contact wall surface of the middle tube and the inner side FRP rib are the same, and the fiber directions of the outer side FRP contact wall surface of the middle tube and the outer side FRP rib are the same.

[0010] Preferably, the outer tube FRP rib, the inner tube FRP rib, the inner side FRP rib of the middle tube and the outer side FRP rib of the middle tube are respectively rotated along the outer tube FRP contact wall surface, the inner tube FRP contact wall surface, the inner side FRP contact wall surface of the middle tube and the outer side FRP contact wall surface of the middle tube, and the rotation mode is single-line unidirectional spiral or multi-line unidirectional spiral.

[0011] Preferably, the distances between adjacent FRP outer tubes and FRP inner tubes, between adjacent FRP outer tubes and FRP middle tubes, and between adjacent FRP middle tubes and FRP inner tubes are each not less than 4 times the maximum particle size of the aggregate in the core concrete, and are each not less than 80mm.

[0012] Preferably, the thicknesses of the outer tube FRP pipe body, the inner tube FRP pipe body and the middle tube FRP pipe body are each not less than 4mm; at the same time, the outer surface of the FRP outer tube is subjected to silica sand sticking treatment by using a high-strength adhesive with a tensile strength not less than 30MPa, the particle size range of the silica sand used is 0.60mm-4.00mm, and the silica sand surface density range of the silica sand sticking layer on the outer surface after the silica sand sticking treatment is 900g / m 2

[0013] -1600g / m 2 .

[0014] Preferably, the configurations of the outer tube FRP rib, the inner tube FRP rib, the inner side FRP rib of the middle tube and the outer side FRP rib of the middle tube should meet the following provisions:

[0015] hr ≥ 3mm

[0016] h r ≥ 0.25 x t b

[0017] h r ≥ 0.009 x h max

[0018]

[0019]

[0020]

[0021] s r ≤ 100mm

[0022] s r ≤ 0.3 x h min

[0023] θ r ≥ 45°

[0024] wherein: h r is the sectional height of the FRP rib along the radial direction of the pipe body; t b is the wall thickness of the FRP pipe, i.e. the sum of the thickness of the pipe body and the thickness of the wall surface; h max is the maximum dimension of the outer contour of the cross section of the FRP pipe; h min is the minimum dimension of the outer contour of the cross section of the FRP pipe (if the outer contour is circular, then h max and h min are each 0.8 times the diameter of the outer contour); w r is the sectional width of the FRP rib along the longitudinal direction of the pipe body; s n is the clear distance between ribs of the FRP rib along the longitudinal direction of the pipe body; s r is the distance between ribs of the FRP rib along the longitudinal direction of the pipe body, s r = w r + s n ; θ r is the included angle between the side surface of the FRP rib and the longitudinal direction of the pipe body.

[0025] A method for manufacturing a high-bonding self-monitoring FRP pipe concrete composite pile, comprising the following steps:

[0026] Step one, determining the length of the pile, the shape and size of the cross section of the pile body, and the maximum bending moment and shear force borne by the pile according to design requirements;

[0027] Step two, determining the lengths of the FRP outer pipe, the FRP inner pipe, and the FRP middle pipe according to the length of the pile;

[0028] Step three, determine whether to set FRP inner tube and FRP middle tube according to the shape and size of the pile cross section and the maximum bending moment and shear force of the pile, and determine the internal design of FRP outer tube, FRP inner tube and FRP middle tube, the strength grade and mix proportion of core concrete, the laying quantity and position of distributed optical fiber sensing optical cable in FRP outer tube, FRP inner tube and FRP middle tube;

[0029] Step four, make corresponding mold and inlay, and prepare FRP outer tube, FRP inner tube and FRP middle tube by using pultrusion-winding process, pultrusion-weaving-winding process or vacuum assisted resin transfer molding process;

[0030] Step five, rinse the outer surface of FRP outer tube with water and wipe it with gauze, evenly apply high-strength adhesive on the outer surface of FRP outer tube, then evenly apply silica sand weighed in the adhesive layer, and let FRP outer tube stand in the room until the adhesive design curing time;

[0031] Step six, process positioning block and packaging end plate, position and bond the relative positions of FRP outer tube, FRP inner tube and FRP middle tube, and use packaging end plate and high-strength adhesive to seal the lower end surface of FRP outer tube, FRP inner tube and FRP middle tube;

[0032] Step seven, use lifting equipment to lift the FRP outer tube, FRP inner tube and FRP middle tube sealed and bonded, and fix them in the vertical direction on the horizontal hardened ground with the help of temporary support members;

[0033] Step eight, install the pouring pipe, pour core concrete into the areas between adjacent FRP outer tube and FRP inner tube, between adjacent FRP outer tube and FRP middle tube, between adjacent FRP middle tube and FRP inner tube, inside FRP outer tube and inside FRP middle tube, vibrate the concrete while pouring, continue to vibrate the core concrete in the depth of 2 meters below the pile top after the core concrete pouring is completed until the concrete stops sinking and no longer bubbles, then smooth the pile top concrete, and maintain it at the temporary fixed position until the design maintenance time of the concrete;

[0034] Step nine, measure and position at the construction site, and lay out the construction position of the composite pile;

[0035] Step ten, lift the FRP pipe concrete composite pile after maintenance, align the measured pile position for pile sinking, when the pile diameter is less than 0.6 meters, it is appropriate to directly use hammering method for pile sinking, and when the pile diameter is greater than 0.6 meters, it can be pre-drilled in the pile foundation hole at the pile position and then use hammering method for pile sinking;

[0036] Step eleven, after the pile sinking is completed, connect the distributed optical fiber sensing optical cable with the distributed optical fiber demodulator by using optical fiber lead wire.

[0037] Preferably, the internal design of the FRP outer tube, the FRP inner tube and the FRP middle tube in step three includes the cross-sectional shape of the FRP outer tube, the FRP inner tube and the FRP middle tube, the thickness and the layer design scheme of each of the outer tube FRP tube body, the inner tube FRP tube body and the middle tube FRP tube body, the thickness and the layer design scheme of each of the outer tube FRP contact wall, the inner tube FRP contact wall, the middle tube inner side FRP contact wall and the middle tube outer side FRP contact wall, and the rotation mode, the cross-sectional shape, the cross-sectional height, the cross-sectional width, the inter-rib clear distance and the layer design scheme of each of the outer tube FRP rib, the inner tube FRP rib, the middle tube inner side FRP rib and the middle tube outer side FRP rib.

[0038] Therefore, the present application has the following beneficial effects by using the above-mentioned high-bond self-monitoring FRP pipe concrete composite pile and the manufacturing method thereof:

[0039] (1) The setting of the FRP rib can significantly enhance the bonding performance of the FRP pipe material-concrete interface; the setting of the FRP contact wall with the same fiber direction as the FRP rib on the surface of the FRP pipe material can reduce the production defects of the FRP pipe material and improve the shear resistance of the FRP rib. The above two mechanisms together enhance the cooperative working performance of the FRP pipe material and the core concrete, so that the mechanical properties of the FRP pipe material can be fully utilized during the stress process of the composite pile, and the bearing capacity of the composite pile is improved.

[0040] (2) The FRP tube body, the FRP pipe wall and the FRP rib are cured and formed by using the pultrusion-winding process, the pultrusion-braiding-winding process or the vacuum-assisted resin transfer molding process in the production process, which eliminates the slotting process of the FRP pipe wall in the existing method, reduces the manufacturing cost of the composite pile foundation, and avoids damage to the FRP pipe material caused by the slotting process.

[0041] (3) The FRP pipe material in the present application includes multiple layers of longitudinal fiber layers and multiple layers of oblique fiber layers, which can provide sufficient longitudinal and transverse constraints for the core concrete in the pipe by means of the good bonding performance of the FRP pipe material and the concrete interface; for pile foundations with lower bearing capacity requirements, the FRP pipe material can fully replace the steel reinforcement; for pile foundations with higher bearing capacity requirements, the FRP pipe material can also partially replace the steel reinforcement, saving the manufacturing and installation steps of the steel reinforcement cage, improving the construction speed, and reducing the construction cost and the life cycle carbon emissions of the pile foundation.

[0042] (4) The sand-bonding treatment on the outer surface of the FRP outer tube can significantly increase the bonding strength of the FRP outer tube-soil interface, improve the side friction resistance of the FRP pipe concrete composite pile, and further improve the bearing capacity of the FRP pipe concrete composite pile.

[0043] (5) By laying the distributed optical fiber sensing optical cable in the longitudinal fiber layer of the FRP pipe, the service state of the FRP pipe concrete composite pile can be monitored in real time, and timely warning can be made before failure, so that the use safety of the structure is effectively ensured.

[0044] The technical solutions of the present application are described in further detail below with the aid of the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 It is a structural schematic diagram of the composite pile in the first embodiment of the present application.

[0046] Figure 2 It is a sectional structural schematic diagram of the composite pile in the first embodiment of the present application.

[0047] Figure 3 It is a sectional structural schematic diagram of the FRP outer pipe in the first embodiment of the present application.

[0048] Figure 4 It is a structural schematic diagram of the FRP outer pipe in the first embodiment of the present application.

[0049] Figure 5 It is a structural schematic diagram of the FRP outer pipe in the first embodiment of the present application.

[0050] Figure 6 It is a construction state schematic diagram of the composite pile in the first embodiment of the present application when pouring core concrete.

[0051] Figure 7 It is a sectional structural schematic diagram of the composite pile in the second embodiment of the present application.

[0052] Figure 8 It is a sectional structural schematic diagram of the composite pile in the third embodiment of the present application.

[0053] Figure 9 It is a sectional structural schematic diagram of the FRP inner pipe in the third embodiment of the present application.

[0054] Figure 10 It is a structural schematic diagram of the FRP inner pipe in the third embodiment of the present application.

[0055] Figure 11 It is a sectional structural schematic diagram of the composite pile after being plugged and adhesively fixed in the third embodiment of the present application.

[0056] Figure 12 It is a structural plan view of the composite pile after being plugged and adhesively fixed in the third embodiment of the present application along the length direction of the FRP pipe.

[0057] Figure 13 It is a sectional structural schematic diagram of the composite pile in the fourth embodiment of the present application.

[0058] Figure 14 Figure 2 is a cross-sectional view of a composite pile according to an embodiment of the present application;

[0059] Figure 15 Figure 3 is a cross-sectional view of a composite pile according to an embodiment of the present application;

[0060] Figure 16 Figure 4 is a cross-sectional view of a layer structure of a FRP middle pipe according to an embodiment of the present application;

[0061] Figure 17 Figure 5 is a structural view of a FRP middle pipe according to an embodiment of the present application;

[0062] Figure 18 Figure 6 is a cross-sectional view of a composite pile according to an embodiment of the present application;

[0063] Figure 19 Figure 7 is a structural view of a FRP middle pipe according to an embodiment of the present application;

[0064] Figure 20 Figure 8 is a cross-sectional view of a composite pile according to an embodiment of the present application;

[0065] Figure 21 Figure 9 is a cross-sectional view of a layer structure of a FRP outer pipe according to an embodiment of the present application;

[0066] Figure 22 Figure 10 is a cross-sectional view of a layer structure of a FRP outer pipe according to an embodiment of the present application;

[0067] Reference signs

[0068] 1. FRP outer pipe; 2. FRP inner pipe; 3. FRP middle pipe; 4. Core concrete; 5. Outer pipe FRP rib; 6. Outer pipe FRP contact wall surface; 7. Outer pipe FRP pipe body; 8. Inner pipe FRP pipe body; 9. Inner pipe FRP contact wall surface; 10. Inner pipe FRP rib; 11. Middle pipe inner side FRP rib; 12. Middle pipe inner side FRP contact wall surface; 13. Middle pipe FRP pipe body; 14. Middle pipe outer side FRP contact wall surface; 15. Middle pipe outer side FRP rib; 16. Longitudinal fiber layer; 17. Oblique fiber layer; 18. Distributed optical fiber sensing optical cable; 19. Positioning block; 20. Encapsulation end plate; 21. Pouring guide pipe. DETAILED DESCRIPTION

[0069] The technical solutions of the present application are further described below through the accompanying drawings and embodiments.

[0070] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the meanings that can be commonly understood by a person with ordinary skill in the art to which the present application belongs. The terms "first", "second", and similar terms in the present application do not denote any order, quantity, or importance, but are used to distinguish different components. The terms "include", "contain", and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like are used only to indicate relative positional relationships, and when the absolute positions of the described objects are changed, the relative positional relationships can also be changed accordingly.

[0071] Embodiments

[0072] Please refer to Figures 1-22 The present application provides a high-bond self-monitoring FRP pipe concrete composite pile, comprising an FRP outer pipe 1, an FRP inner pipe 2, an FRP middle pipe 3, and core concrete 4. The core concrete 4 is filled between the adjacent FRP outer pipe 1 and FRP inner pipe 2, between the FRP outer pipe 1 and FRP middle pipe 3, between the FRP middle pipe 3 and FRP inner pipe 2, inside the FRP outer pipe 1, and inside the FRP middle pipe 3. The FRP inner pipe 2 and the FRP middle pipe 3 are both arranged inside the FRP outer pipe 1. The FRP inner pipe 2 and the FRP middle pipe 3 can both be provided with zero or one root.

[0073] The FRP outer pipe 1 comprises, from the inside to the outside, an outer pipe FRP rib 5, an outer pipe FRP contact wall surface 6, and an outer pipe FRP pipe body 7. The outer pipe FRP pipe body 7 comprises a plurality of layers of longitudinal fiber plies 16, a plurality of layers of oblique fiber plies 17, and 0-4 distributed optical fiber sensing optical cables 18. The oblique fiber plies 17 have an included angle with the longitudinal direction of the outer pipe FRP pipe body 7 in the range of (0°, 90°], preferably in the range of (75°, 90°]. The distributed optical fiber sensing optical cables 18 are arranged in the longitudinal fiber plies 16 of the outer pipe FRP pipe body 7 along the longitudinal direction.

[0074] The outer pipe FRP contact wall surface 6 comprises a plurality of layers of oblique fiber plies 17 with the same fiber direction. The outer pipe FRP rib 5 is attached to the surface of the outer pipe FRP contact wall surface 6, and the fiber direction of the outer pipe FRP contact wall surface 6 is the same as that of the outer pipe FRP rib 5. The outer pipe FRP rib 5 is arranged in a single-line single-direction spiral or a multi-line single-direction spiral along the rotation mode of the outer pipe FRP contact wall surface 6.

[0075] The outer surface of the FRP outer tube 1 is subjected to silica sanding treatment with a high-strength adhesive having a tensile strength not less than 30 MPa, and the silica sand used has a particle size range of 0.60 mm-4.00 mm, preferably 1.18 mm-2.36 mm. The silica sand surface density of the sanding layer on the outer surface after sanding treatment is not less than 900 g / m 2 and not more than 1600 g / m 2 .

[0076] The FRP inner tube 2 comprises, from inside to outside, an inner tube FRP tube body 8, an inner tube FRP contact wall 9, and an inner tube FRP rib 10. The inner tube FRP tube body 8 comprises multiple layers of longitudinal fiber plies 16, multiple layers of oblique fiber plies 17, and 0-4 distributed optical fiber sensing cables 18. The oblique fiber plies 17 have an angle with the longitudinal direction of the inner tube FRP tube body 8 in the range of (0°, 90°], preferably in the range of (75°, 90°]. The distributed optical fiber sensing cables 18 are laid in a certain longitudinal fiber ply 16 of the inner tube FRP tube body 8 along the longitudinal direction.

[0077] The inner tube FRP contact wall 9 comprises several layers of oblique fiber plies 17 with the same fiber direction. The inner tube FRP contact wall 9 has the inner tube FRP rib 10 attached to its surface, and the fiber direction of the inner tube FRP contact wall 9 is the same as that of the inner tube FRP rib 10. The inner tube FRP rib 10 is in the form of single-line unidirectional spiral or multi-line unidirectional spiral along the rotation of the inner tube FRP contact wall 9.

[0078] The FRP middle tube 3 comprises, from inside to outside, a middle tube inner side FRP rib 11, a middle tube inner side FRP contact wall 12, a middle tube FRP tube body 13, a middle tube outer side FRP contact wall 14, and a middle tube outer side FRP rib 15. The middle tube FRP tube body 13 comprises multiple layers of longitudinal fiber plies 16, multiple layers of oblique fiber plies 17, and 0-4 distributed optical fiber sensing cables 18. The oblique fiber plies 17 have an angle with the longitudinal direction of the middle tube FRP tube body 13 in the range of (0°, 90°], preferably in the range of (75°, 90°]. The distributed optical fiber sensing cables 18 are laid in a certain longitudinal fiber ply 16 of the middle tube FRP tube body 13 along the longitudinal direction.

[0079] The inner FRP contact wall 12 and the outer FRP contact wall 14 of the middle tube each comprise several layers of oblique fiber plies 17 in the same fiber direction, and the inner surface of the inner FRP contact wall 12 is attached with the inner FRP rib 11 of the middle tube, the outer surface of the outer FRP contact wall 14 is attached with the outer FRP rib 15 of the middle tube, the fiber direction of the inner FRP contact wall 12 is the same as that of the inner FRP rib 11 of the middle tube, and the fiber direction of the outer FRP contact wall 14 is the same as that of the outer FRP rib 15 of the middle tube. The inner FRP rib 11 of the middle tube is in a single-line unidirectional spiral or a multi-line unidirectional spiral along the inner FRP contact wall 12 of the middle tube; and the outer FRP rib 15 of the middle tube is in a single-line unidirectional spiral or a multi-line unidirectional spiral along the outer FRP contact wall 14 of the middle tube.

[0080] The cross-sectional shape of the outer FRP rib 5, the inner FRP rib 10, the inner FRP rib 11 of the middle tube and the outer FRP rib 15 of the middle tube is rectangular, rounded rectangular, trapezoidal or rounded trapezoidal. The arrangement of the outer FRP rib 5, the inner FRP rib 10, the inner FRP rib 11 of the middle tube and the outer FRP rib 15 of the middle tube should meet the following requirements:

[0081] h r ≥3mm;

[0082] h r ≥0.25xt b ;

[0083] h r ≥0.009xh max ;

[0084]

[0085]

[0086]

[0087] s r ≤100mm;

[0088] s r ≤0.3xh min ;

[0089] θ r ≥45°;

[0090] In the formula, h r is the cross-sectional height of the FRP rib along the radial direction of the tube body; t b is the wall thickness of the FRP tube (i.e. the sum of the thickness of the tube body and the thickness of the wall); h max is the maximum size of the outer contour of the cross-section of the FRP tube (if the outer contour is circular, take 0.8 times the diameter); h minis the minimum dimension of the outer profile of the cross section of the FRP tube (if the outer profile is circular, take 0.8 times the diameter); w r is the cross-sectional width of the FRP rib along the longitudinal direction of the tube body; s n is the cross-sectional width of the FRP rib along the longitudinal direction of the tube body; s r is the cross-sectional width of the FRP rib along the longitudinal direction of the tube body; s r = w r +s n ; θ r is the angle between the side surface of the FRP rib and the longitudinal direction of the tube body.

[0091] The core concrete 4 fills the areas between adjacent FRP outer tubes 1 and FRP inner tubes 2, between adjacent FRP outer tubes 1 and FRP middle tubes 3, between adjacent FRP middle tubes 3 and FRP inner tubes 2, inside the FRP outer tubes 1, and inside the FRP middle tubes 3; the core concrete 4 is in contact with the outer tube FRP ribs 5, the outer tube FRP contact wall surfaces 6, the inner tube FRP ribs 10, the inner tube FRP contact wall surfaces 9, the middle tube inner side FRP ribs 11, the middle tube inner side FRP contact wall surfaces 12, the middle tube outer side FRP ribs 15, and the middle tube outer side FRP contact wall surfaces 14.

[0092] The distances between adjacent FRP outer tubes 1 and FRP inner tubes 2, between adjacent FRP outer tubes 1 and FRP middle tubes 3, and between adjacent FRP middle tubes 3 and FRP inner tubes 2 are all not less than 4 times the maximum particle size of the aggregate in the core concrete 4, and are all not less than 80 mm, so as to ensure smooth flow of the concrete during construction, thereby ensuring that the core concrete 4 is dense and has no voids after construction is completed. The core concrete 4 is preferably micro-expanding concrete mixed with an expanding agent, the maximum particle size of the aggregate in the core concrete 4 is not more than 40 mm, and the strength grade of the core concrete 4 is not less than C30.

[0093] The thicknesses of the outer tube FRP tube body 7, the inner tube FRP tube body 8, and the middle tube FRP tube body 13 are all not less than 4 mm. The FRP outer tubes 1, the FRP inner tubes 2, and the FRP middle tubes 3 of the same high-bond self-monitoring FRP tube concrete composite pile can have different cross-sectional shapes, so as to fully exert the mechanical properties of the materials under the premise of ensuring the applicability of the components.

[0094] The FRP outer tubes 1, the FRP inner tubes 2, and the FRP middle tubes 3 are manufactured in a factory by using a pultrusion-winding process, a pultrusion-braiding-winding process, or a vacuum-assisted resin transfer molding process. The fibers of the FRP outer tubes 1, the FRP inner tubes 2, and the FRP middle tubes 3 are basalt fibers, carbon fibers, aramid fibers, glass fibers, or hybrid fibers composed of two or more of the above fibers; and the matrix resin of the FRP outer tubes 1, the FRP inner tubes 2, and the FRP middle tubes 3 can be vinyl ester resin, epoxy resin, or unsaturated polyester resin.

[0095] The application discloses a manufacturing method of a high-bond self-monitoring FRP pipe concrete composite pile.

[0096] (1) According to the design requirements, the length of the pile, the cross-sectional shape and size of the pile body, the maximum bending moment and shear force of the pile are determined.

[0097] (2) According to the length of the pile, the lengths of the FRP outer pipe 1, the FRP inner pipe 2 and the FRP middle pipe 3 are determined.

[0098] (3) According to the cross-sectional shape and size of the pile body, the maximum bending moment and shear force of the pile, whether the FRP inner pipe 2 and the FRP middle pipe 3 are arranged or not is determined, the cross-sectional shape of the FRP outer pipe 1, the FRP inner pipe 2 and the FRP middle pipe 3, the thickness and the layer design scheme (the layer design scheme includes the type of base resin, the total number of layers, and the thickness, fiber type, fiber volume fraction and fiber direction of each layer) of the outer pipe FRP pipe body 7, the inner pipe FRP pipe body 8 and the middle pipe FRP pipe body 13, the thickness and the layer design scheme of the outer pipe FRP contact wall 6, the inner pipe FRP contact wall 9, the middle pipe inner side FRP contact wall 12 and the middle pipe outer side FRP contact wall 14, the rotation mode, the cross-sectional shape, the cross-sectional height, the cross-sectional width, the rib spacing and the layer design scheme of the outer pipe FRP rib 5, the inner pipe FRP rib 10, the middle pipe inner side FRP rib 11 and the middle pipe outer side FRP rib 15, and the strength grade and the mix ratio design scheme of the core concrete 4 are determined; according to the monitoring requirement of the pile foundation, the laying number and the laying position of the distributed optical fiber sensing optical cable 18 in the outer pipe FRP pipe body 7, the inner pipe FRP pipe body 8 and the middle pipe FRP pipe body 13 are determined.

[0099] (4) In the factory, corresponding molds and inlays are manufactured, and the FRP outer pipe 1, the FRP inner pipe 2 and the FRP middle pipe 3 are prepared by using a pultrusion-winding process, a pultrusion-braiding-winding process or a vacuum-assisted resin transfer molding process.

[0100] (5) The outer surface of the FRP outer pipe is washed with clean water and wiped dry with gauze, high-strength adhesive with a tensile strength of not less than 30 MPa is evenly applied to the outer surface of the FRP outer pipe, and then the weighed silica sand is evenly applied to the adhesive layer, and the FRP outer pipe is placed indoors until the adhesive reaches the designed curing time.

[0101] (6) Process the positioning block 19 and the encapsulation end plate 20. The positioning block 19 and the high-strength adhesive are used to position and bond the relative positions of the FRP outer tube 1, the FRP inner tube 2 and the FRP middle tube 3, and then the encapsulation end plate 20 and the high-strength adhesive are used to seal the lower end faces of the FRP outer tube 1, the FRP inner tube 2 and the FRP middle tube 3. The exposed part of the distributed optical fiber sensing optical cable 18 is wrapped with a bubble film, and then temporarily fixed at a suitable position on the surface of the FRP tube to prevent damage to the optical fiber during construction. If there is no FRP inner tube 2 and no FRP middle tube 3 in the FRP pipe concrete composite pile, the positioning block 19 does not need to be made.

[0102] (7) The FRP outer tube 1, the FRP inner tube 2 and the FRP middle tube 3 that have been sealed and bonded are lifted by lifting equipment and fixed in the vertical direction on the horizontal hardened ground with the help of temporary support members.

[0103] (8) Install the pouring guide pipe 21, pay attention to avoid collision between the pouring guide pipe 21 and the FRP outer tube 1, the FRP inner tube 2 or the FRP middle tube 3, and pour the core concrete 4 into the areas between adjacent FRP outer tubes 1 and FRP inner tubes 2, between adjacent FRP outer tubes 1 and FRP middle tubes 3, between adjacent FRP middle tubes 3 and FRP inner tubes 2, inside the FRP outer tube 1 and inside the FRP middle tube 3. Vibrate the concrete while pouring to ensure that the core concrete 4 is poured densely. After the core concrete 4 is poured, continue to vibrate the core concrete 4 within a depth of 2 meters below the pile top until the concrete stops sinking and no longer bubbles, and then smooth the concrete at the pile top. Curing at the temporary fixing position until the design curing time of the concrete.

[0104] (9) Measure and position at the construction site to lay out the construction position of the composite pile.

[0105] (10) Lift the FRP pipe concrete composite pile after curing, and align the measured pile position for pile sinking. When the pile diameter is less than 0.6 meters, it is appropriate to directly use the hammering method to sink the pile: the pile machine is in place, the FRP pipe concrete composite pile is lifted and aligned with the measured pile position and slowly lowered into the soil, a pile cushion is placed between the pile top and the pile driver, the pile body verticality is corrected to within 0.5%, the pile is lightly hit several times with the pile hammer on the top surface of the composite pile, the pile is sunk into the soil by 1-2 meters to reach a stable position, the pile position horizontal deviation and the pile body verticality are corrected again, and then the pile is uniformly driven to the design elevation. When the pile diameter is greater than 0.6 meters, a suitable drill can be selected according to the construction site conditions to drill a pilot hole for the pile foundation at the pile position before sinking the pile. The diameter of the pilot hole is 0.05-0.1 meters smaller than the diameter of the pile, and the depth of the pilot hole is 0.5-0.7 times the length of the pile, and then the pile is sunk by the hammering method.

[0106] (11) After the completion of pile sinking, the horizontal deviation and the top elevation deviation of the composite pile are checked. Then, the distributed optical fiber sensing cable 18 is connected to the distributed optical fiber demodulator through an optical fiber lead.

[0107] In the first embodiment, the high-bond self-monitoring FRP pipe concrete composite pile comprises an FRP outer pipe 1 with a circular cross-sectional profile and a core concrete 4, as shown in the following figure. Figures 1-6

[0108] The length of the pile body is 3.3 m. The outer profile diameter of the FRP outer pipe 1 is 240 mm, which is produced by basalt fiber and epoxy resin through pultrusion-winding process. The thickness of the outer pipe FRP body 7 is 7 mm, in which 4 distributed optical fiber sensing cables 18 are uniformly arranged. The outer pipe FRP body 7 comprises 5 layers of longitudinal fiber plies 16 and 2 layers of oblique fiber plies 17, in which the fiber direction of the 2 layers of oblique fiber plies 17 is 86° to the longitudinal direction of the FRP outer pipe 1 and the fiber rotation directions are opposite. The thickness of the outer pipe FRP contact wall 6 is 1 mm, which is composed of one layer of oblique fiber plies 17. The fiber direction of the outer pipe FRP contact wall 6 is the same as that of the outer pipe FRP rib 5, which is 86° to the longitudinal direction of the FRP outer pipe 1. The cross-sectional shape of the outer pipe FRP rib 5 is rectangular, and the rotation mode along the outer pipe FRP contact wall 6 is single-line unidirectional spiral. The cross-sectional height of the outer pipe FRP rib 5 along the radial direction of the FRP outer pipe 1 is 4 mm, and the cross-sectional width along the longitudinal direction of the FRP outer pipe 1 is 16 mm. The rib-to-rib clear distance of the outer pipe FRP rib 5 is 33.2 mm. The core concrete 4 is filled in the interior of the FRP outer pipe 1, the maximum particle size of the aggregate is 15 mm, and the strength grade is C40.

[0109] The manufacturing method of the high-bond self-monitoring FRP pipe concrete composite pile of the present embodiment comprises the following steps:

[0110] (1) Determine the pile length, pile cross-sectional shape and size, maximum bending moment and shear force of the pile according to the design requirements.

[0111] (2) Determine the length of the FRP outer pipe 1 according to the pile length.

[0112] ​(3) According to the cross-sectional shape and size of the pile body and the maximum bending moment and shear force of the pile, it is determined that the FRP pipe concrete composite pile does not set the FRP inner tube 2 and the FRP middle tube 3; further, the cross-sectional shape of the outer tube FRP pipe body 7, the thickness and layer design scheme of the outer tube FRP contact wall 6, the rotation mode, cross-sectional shape, cross-sectional height, cross-sectional width, rib spacing and layer design scheme of the outer tube FRP rib 5, the strength grade and mix design scheme of the core concrete 4 are determined. According to the monitoring requirements of the pile foundation, the laying number and laying position of the distributed optical fiber sensing optical cable 18 in the outer tube FRP pipe body 7 are determined. The determined parameters are as described above.

[0113] (4) In the factory, the corresponding mold and insert are made, and the FRP outer tube 1 is prepared by pultrusion-winding process.

[0114] (5) The outer surface of the FRP outer tube is washed clean with clean water and wiped dry with gauze, and the outer surface of the FRP outer tube is evenly brushed with the mixed high-strength epoxy resin adhesive to make the adhesive thickness about 0.2mm-0.3mm, then the weighed silica sand with particle size range of 1.18mm-2.36mm is evenly applied in the adhesive layer, the uniformity of the sand-adhesive layer is visually and manually controlled, and then the FRP outer tube is placed indoors until the adhesive design curing time.

[0115] (6) The packaging end plate 20 is processed and made, the lower end surface of the FRP outer tube 1 is sealed with the packaging end plate 20 and high-strength adhesive; the exposed part of the distributed optical fiber sensing optical cable 18 is wrapped with bubble film, and then it is temporarily fixed at a suitable position on the surface of the FRP pipe to prevent damage to the optical fiber during construction.

[0116] (7) The sealed FRP outer tube 1 is lifted by lifting equipment and fixed in the vertical direction on the horizontal hardened ground with the help of temporary support members.

[0117] (8) The pouring pipe 21 is installed, and attention should be paid to avoid collision between the pouring pipe 21 and the FRP outer tube 1, and the core concrete 4 is poured into the inner area of the FRP outer tube 1, the concrete is vibrated while pouring to ensure that the core concrete 4 is poured densely. After the core concrete 4 is poured, the core concrete 4 within 2 meters below the pile top is continuously vibrated until the concrete stops sinking and no longer bubbles, and then the pile top concrete is smoothed. Curing at the temporary fixing position until the designed curing time of the concrete.

[0118] (9) The construction site is measured and positioned, and the construction position of the composite pile is laid out.

[0119] (10) The FRP pipe concrete composite pile after maintenance is lifted, aligned with the measured pile position, and slowly lowered into the soil. A pile cushion is placed between the pile top and the pile driver, and the pile verticality is corrected to within 0.5%. The pile is lightly hit on the top surface by the pile driver for several times, so that the pile sinks into the soil by 1 m to reach a stable position. The pile position horizontal deviation and the pile verticality are corrected again, and then the pile is driven at a uniform speed to the design elevation.

[0120] (11) After the pile driving is completed, the composite pile position horizontal deviation and the pile top elevation deviation are checked. Then, the distributed optical fiber sensing cable 18 is connected to the distributed optical fiber demodulator by using an optical fiber lead.

[0121] In Example 2, the high-bond self-monitoring FRP pipe concrete composite pile includes an FRP outer pipe 1 with a cross-sectional profile of a rounded square and a core concrete 4.

[0122] The pile length is 3.6 m. The outer profile side length of the FRP outer pipe 1 is 240 mm, which is produced by using basalt fibers and epoxy resin through a pultrusion-winding process. The thickness of the outer pipe FRP pipe body 7 is 7 mm, in which 4 distributed optical fiber sensing cables 18 are uniformly arranged. The outer pipe FRP pipe body 7 includes 5 layers of longitudinal fiber plies 16 and 2 layers of oblique fiber plies 17, in which the fiber directions of the 2 layers of oblique fiber plies 17 are both at an 86° angle with the longitudinal direction of the FRP outer pipe 1 and the fiber rotation directions are opposite. The thickness of the outer pipe FRP contact wall 6 is 1 mm, which is composed of one layer of oblique fiber plies 17. The fiber direction of the outer pipe FRP contact wall 6 is the same as that of the outer pipe FRP rib 5, which is at an 86° angle with the longitudinal direction of the FRP outer pipe 1. The cross-sectional shape of the outer pipe FRP rib 5 is rectangular, and the rotation mode along the outer pipe FRP contact wall 6 is single-line unidirectional spiral. The cross-sectional height of the outer pipe FRP rib 5 along the radial direction of the FRP outer pipe 1 is 4 mm, and the cross-sectional width along the longitudinal direction of the FRP outer pipe 1 is 16 mm. The rib-to-rib clear distance of the outer pipe FRP rib 5 is 45.5 mm. The core concrete 4 is filled in the FRP outer pipe 1, the maximum particle size of the aggregate is 15 mm, and the strength grade is C40.

[0123] The manufacturing method is the same as that of Example 1, which is not described herein.

[0124] Example 3

[0125] Referring to FIG. 1, Figures 8-12 The high-bond self-monitoring FRP pipe concrete composite pile includes an FRP outer pipe 1 with a cross-sectional profile of a circle, an FRP inner pipe 2 with a cross-sectional profile of a circle, and a core concrete 4.

[0126] The length of the pile body is 7.2 m. The outer profile diameter of the FRP outer tube 1 is 480 mm, and the outer profile diameter of the FRP inner tube 2 is 240 mm. Both the FRP outer tube 1 and the FRP inner tube 2 are produced by the pultrusion-winding process using basalt fibers and epoxy resin.

[0127] The thickness of the outer tube FRP pipe body 7 is 10 mm, in which 4 distributed optical fiber sensing cables 18 are uniformly arranged. The outer tube FRP pipe body 7 comprises 6 layers of longitudinal fiber plies 16 and 4 layers of oblique fiber plies 17, in which the fiber directions of the 4 layers of oblique fiber plies 17 are all at an 86° angle with the longitudinal direction of the FRP outer tube 1. The thickness of the outer tube FRP contact wall 6 is 2 mm, which comprises two layers of oblique fiber plies 17 with the same fiber direction. The fiber direction of the outer tube FRP contact wall 6 is the same as that of the outer tube FRP rib 5, which is at an 86° angle with the longitudinal direction of the FRP outer tube 1. The cross-sectional shape of the outer tube FRP rib 5 is rectangular, and the rotation mode along the outer tube FRP contact wall 6 is a double-line unidirectional spiral. The cross-sectional height of the outer tube FRP rib 5 along the radial direction of the FRP outer tube 1 is 5 mm, and the cross-sectional width along the longitudinal direction of the FRP outer tube 1 is 20 mm. The inter-rib clear distance of the outer tube FRP rib 5 is 30.1 mm.

[0128] The thickness of the inner tube FRP pipe body 8 is 7 mm, in which 4 distributed optical fiber sensing cables 18 are uniformly arranged. The inner tube FRP pipe body 8 comprises 4 layers of longitudinal fiber plies 16 and 3 layers of oblique fiber plies 17, in which the fiber directions of the 3 layers of oblique fiber plies 17 are all at an 86° angle with the longitudinal direction of the FRP inner tube 2. The thickness of the inner tube FRP contact wall 9 is 2 mm, which comprises two layers of oblique fiber plies 17 with the same fiber direction. The fiber direction of the inner tube FRP contact wall 9 is the same as that of the inner tube FRP rib 10, which is at an 86° angle with the longitudinal direction of the FRP inner tube 2. The cross-sectional shape of the inner tube FRP rib 10 is rectangular, and the rotation mode along the inner tube FRP contact wall 9 is a single-line unidirectional spiral. The cross-sectional height of the inner tube FRP rib 10 along the radial direction of the FRP inner tube 2 is 4 mm, and the cross-sectional width along the longitudinal direction of the FRP inner tube 2 is 16 mm. The inter-rib clear distance of the inner tube FRP rib 10 is 36.7 mm.

[0129] The core concrete 4 is filled between the FRP outer tube 1 and the FRP inner tube 2, the maximum particle size of the aggregate is 15 mm, and the strength grade is C40.

[0130] The FRP inner tube 2 and the FRP middle tube 3 of the FRP pipe concrete composite pile are not arranged according to the cross-sectional shape and size of the pile body and the maximum bending moment and shear force borne by the pile; the cross-sectional shape of the FRP outer tube 1, the thickness and layer design scheme of the outer tube FRP pipe body 7, the thickness and layer design scheme of the outer tube FRP contact wall 6, the rotation mode, cross-sectional shape, cross-sectional height, cross-sectional width, rib interval and layer design scheme of the outer tube FRP rib 5, and the strength grade and mix design scheme of the core concrete 4 are further determined. The laying number and laying position of the distributed optical fiber sensing optical cable 18 in the outer tube FRP pipe body 7 are determined according to the monitoring requirements of the pile foundation. The determined parameters are as described above. The remaining manufacturing method is the same as that of Embodiment One, and will not be described here.

[0131] Embodiment Four

[0132] Referring to Figure 13 As shown in the figure, the high-bond self-monitoring FRP pipe concrete composite pile of the embodiment includes an FRP outer tube 1 with a cross-sectional profile of a rounded square, an FRP inner tube 2 with a cross-sectional profile of a rounded square, and a core concrete 4. The length of the pile body is 7.8 m.

[0133] The outer profile side length of the FRP outer tube 1 is 480 mm, and the outer profile side length of the FRP inner tube 2 is 240 mm. The FRP outer tube 1 and the FRP inner tube 2 are produced by the pultrusion-winding process of basalt fibers and epoxy resin.

[0134] The thickness of the outer tube FRP pipe body 7 is 10 mm, in which 4 distributed optical fiber sensing optical cables 18 are uniformly arranged. The outer tube FRP pipe body 7 includes 6 layers of longitudinal fiber layers 16 and 4 layers of oblique fiber layers 17, in which the fiber direction of the 4 layers of oblique fiber layers 17 is at an 86° angle with the longitudinal direction of the FRP outer tube 1. The thickness of the outer tube FRP contact wall 6 is 2 mm, including two layers of oblique fiber layers 17 with the same fiber direction. The fiber direction of the outer tube FRP contact wall 6 is the same as that of the outer tube FRP rib 5, both of which are at an 86° angle with the longitudinal direction of the FRP outer tube 1. The cross-sectional shape of the outer tube FRP rib 5 is rectangular, and the rotation mode along the outer tube FRP contact wall 6 is a double-line unidirectional spiral. The cross-sectional height of the outer tube FRP rib 5 along the radial direction of the FRP outer tube 1 is 5 mm, and the cross-sectional width along the longitudinal direction of the FRP outer tube 1 is 20 mm. The rib interval of the outer tube FRP rib 5 is 43.2 mm.

[0135] The thickness of the inner tube FRP pipe body 8 is 7 mm, in which 4 distributed optical fiber sensing cables 18 are uniformly arranged. The inner tube FRP pipe body 8 comprises 4 layers of longitudinal fiber plies 16 and 3 layers of oblique fiber plies 17, in which the fiber direction of the 3 layers of oblique fiber plies 17 is at an 86° angle with the longitudinal direction of the FRP inner tube 2. The thickness of the inner tube FRP contact wall 9 is 2 mm, which comprises two layers of oblique fiber plies 17 with the same fiber direction. The fiber direction of the inner tube FRP contact wall 9 is the same as that of the inner tube FRP rib 10, which is at an 86° angle with the longitudinal direction of the FRP inner tube 2. The cross-sectional shape of the inner tube FRP rib 10 is rectangular, and the rotation mode of the inner tube FRP rib 10 along the inner tube FRP contact wall 9 is single-line unidirectional spiral. The cross-sectional height of the inner tube FRP rib 10 along the radial direction of the FRP inner tube 2 is 4 mm, and the cross-sectional width of the inner tube FRP rib 10 along the longitudinal direction of the FRP inner tube 2 is 16 mm. The rib-to-rib clear distance of the inner tube FRP rib 10 is 49.9 mm.

[0136] The core concrete 4 is filled between the FRP outer tube 1 and the FRP inner tube 2, the maximum particle size of the aggregate is 15 mm, and the strength grade is C40.

[0137] The manufacturing method of the FRP pipe concrete composite pile of the embodiment is the same as that of example three, and will not be repeated here.

[0138] Example five

[0139] Referring to Figure 14 The high-bond self-monitoring FRP pipe concrete composite pile of the embodiment comprises an FRP outer tube 1 with a cross-sectional profile of a rounded square, an FRP inner tube 2 with a cross-sectional profile of a circle, and a core concrete 4. The length of the pile body of the FRP pipe concrete composite pile is 12 m.

[0140] The outer profile side length of the FRP outer tube 1 is 660 mm, and the outer profile diameter of the FRP inner tube 2 is 390 mm. The FRP outer tube 1 and the FRP inner tube 2 are both produced by the pultrusion-winding process of basalt fibers and epoxy resin.

[0141] The outer tube FRP pipe body 7 has a thickness of 12 mm, in which 4 distributed optical fiber sensing cables 18 are uniformly arranged; the outer tube FRP pipe body 7 comprises 7 layers of longitudinal fiber plies 16 and 5 layers of oblique fiber plies 17, in which the fiber directions of the 5 layers of oblique fiber plies 17 are all at an angle of 87° with the longitudinal direction of the FRP outer tube 1. The outer tube FRP contact wall surface 6 has a thickness of 2 mm and comprises two layers of oblique fiber plies 17 with the same fiber direction. The fiber direction of the outer tube FRP contact wall surface 6 is the same as that of the outer tube FRP rib 5, and is at an angle of 87° with the longitudinal direction of the FRP outer tube 1. The outer tube FRP rib 5 has a rectangular cross-sectional shape, and the rotation mode along the outer tube FRP contact wall surface 6 is a double-line unidirectional spiral. The cross-sectional height of the outer tube FRP rib 5 along the radial direction of the FRP outer tube 1 is 6 mm, and the cross-sectional width along the longitudinal direction of the FRP outer tube 1 is 20 mm. The rib-to-rib clear distance of the outer tube FRP rib 5 is 45.6 mm.

[0142] The inner tube FRP pipe body 8 has a thickness of 9 mm, in which 4 distributed optical fiber sensing cables 18 are uniformly arranged; the inner tube FRP pipe body 8 comprises 5 layers of longitudinal fiber plies 16 and 4 layers of oblique fiber plies 17, in which the fiber directions of the 4 layers of oblique fiber plies 17 are all at an angle of 87° with the longitudinal direction of the FRP inner tube 2. The inner tube FRP contact wall surface 9 has a thickness of 2 mm and comprises two layers of oblique fiber plies 17 with the same fiber direction. The fiber direction of the inner tube FRP contact wall surface 9 is the same as that of the inner tube FRP rib 10, and is at an angle of 87° with the longitudinal direction of the FRP inner tube 2. The inner tube FRP rib 10 has a rectangular cross-sectional shape, and the rotation mode along the inner tube FRP contact wall surface 9 is a single-line unidirectional spiral. The cross-sectional height of the inner tube FRP rib 10 along the radial direction of the FRP inner tube 2 is 5 mm, and the cross-sectional width along the longitudinal direction of the FRP inner tube 2 is 20 mm. The rib-to-rib clear distance of the inner tube FRP rib 10 is 44.2 mm.

[0143] The core concrete 4 is filled between the FRP outer tube 1 and the FRP inner tube 2, the maximum particle size of the aggregate is 15 mm, and the strength grade is C40.

[0144] The manufacturing method of the FRP pipe concrete composite pile of the embodiment is the same as that of Embodiment Three, and details are not repeated here.

[0145] Embodiment Six

[0146] Referring to Figures 15-17 As shown in the figure, the high-bond self-monitoring FRP pipe concrete composite pile of the embodiment comprises an FRP outer tube 1 with a circular-rectangular cross-sectional profile, an FRP middle tube 3 with a circular cross-sectional profile, and a core concrete 4. The length of the pile body of the FRP pipe concrete composite pile is 13.8 m.

[0147] The outer profile length of the FRP outer tube 1 is 660 mm, and the outer profile diameter of the FRP middle tube 3 is 390 mm. The FRP outer tube 1 is produced by using basalt fiber and epoxy resin through the pultrusion-winding process, and the FRP middle tube 3 is produced by using basalt fiber and epoxy resin through the vacuum-assisted resin transfer molding process.

[0148] The thickness of the outer tube FRP pipe body 7 is 12 mm, and 4 distributed optical fiber sensing optical cables 18 are uniformly arranged therein. The outer tube FRP pipe body 7 comprises 7 layers of longitudinal fiber plies 16 and 5 layers of oblique fiber plies 17, and the fiber directions of the 5 layers of oblique fiber plies 17 are all at an angle of 87° with the longitudinal direction of the FRP outer tube 1. The thickness of the outer tube FRP contact wall 6 is 2 mm, and it comprises two layers of oblique fiber plies 17 with the same fiber direction. The fiber direction of the outer tube FRP contact wall 6 is the same as that of the outer tube FRP rib 5, and both are at an angle of 87° with the longitudinal direction of the FRP outer tube 1. The cross-sectional shape of the outer tube FRP rib 5 is rectangular, and the rotation mode of the outer tube FRP rib 5 along the outer tube FRP contact wall 6 is double-line unidirectional spiral. The cross-sectional height of the outer tube FRP rib 5 along the radial direction of the FRP outer tube 1 is 6 mm, and the cross-sectional width of the outer tube FRP rib 5 along the longitudinal direction of the FRP outer tube 1 is 20 mm. The rib-to-rib clear distance of the outer tube FRP rib 5 is 45.6 mm.

[0149] The thickness of the middle tube FRP pipe body 13 is 9 mm, and 4 distributed optical fiber sensing optical cables 18 are uniformly arranged therein. The middle tube FRP pipe body 13 comprises 5 layers of longitudinal fiber plies 16 and 4 layers of oblique fiber plies 17, and the fiber directions of the 4 layers of oblique fiber plies 17 are all at an angle of 87° with the longitudinal direction of the FRP middle tube 3. The thickness of the middle tube inner side FRP contact wall 12 and the middle tube outer side FRP contact wall 14 is 1 mm, and each comprises a layer of oblique fiber ply 17. The fiber directions of the middle tube inner side FRP contact wall 12, the middle tube outer side FRP contact wall 14, the middle tube inner side FRP rib 11 and the middle tube outer side FRP rib 15 are the same, and all are at an angle of 87° with the longitudinal direction of the FRP middle tube 3. The cross-sectional shape of the middle tube inner side FRP rib 11 and the middle tube outer side FRP rib 15 is rectangular, and they respectively rotate along the middle tube inner side FRP contact wall 12 and the middle tube outer side FRP contact wall 14 in a single-line unidirectional spiral. The cross-sectional height of the middle tube inner side FRP rib 11 and the middle tube outer side FRP rib 15 along the radial direction of the FRP middle tube 3 is 5 mm, and the cross-sectional width of the middle tube inner side FRP rib 11 and the middle tube outer side FRP rib 15 along the longitudinal direction of the FRP middle tube 3 is 20 mm. The rib-to-rib clear distance of the middle tube inner side FRP rib 11 is 40.6 mm, and the rib-to-rib clear distance of the middle tube outer side FRP rib 15 is 44.2 mm.

[0150] The core concrete 4 is filled in the FRP middle tube 3 and between the FRP outer tube 1 and the FRP middle tube 3, and the maximum particle size of the aggregate is 15 mm, and the strength grade is C40.

[0151] Based on the cross-sectional shape and dimensions of the pile body, as well as the maximum bending moment and shear force experienced by the pile, the FRP-concrete composite pile is designed with one FRP outer tube 1 and one FRP middle tube 3, without an FRP inner tube 2. Further details are provided: the cross-sectional shapes of the FRP outer tube 1 and FRP middle tube 3; the thickness and layup design of the FRP body 7 of the outer tube and the FRP body 13 of the middle tube; the thickness and layup design of the FRP contact wall 6 of the outer tube, the FRP contact wall 12 inside the middle tube, and the FRP contact wall 14 outside the middle tube; the rotation method, cross-sectional shape, cross-sectional height, cross-sectional width, net spacing between ribs, and layup design of the FRP ribs 5 of the outer tube, 11 inside the middle tube, and 15 outside the middle tube; and the strength grade and mix design of the core concrete 4. The number and location of distributed optical fiber sensing cables 18 in the FRP body 7 and the FRP body 13 of the outer tube are determined according to the pile foundation monitoring requirements. The parameters are as described above. The remaining manufacturing methods are the same as in Example 1, and will not be repeated here.

[0152] Example 7

[0153] See Figure 18 , Figure 19 As shown, the high-bonding self-monitoring FRP pipe-concrete composite pile of this embodiment includes an FRP outer pipe 1 with a circular cross-sectional profile, an FRP middle pipe 3 with a circular cross-sectional profile, an FRP inner pipe 2 with a circular cross-sectional profile, and core concrete 4. The pile length of the FRP pipe-concrete composite pile is 19.6m.

[0154] The outer diameters of FRP outer tube 1, FRP middle tube 3, and FRP inner tube 2 are 980mm, 730mm, and 480mm, respectively. FRP outer tube 1 and FRP inner tube 2 are produced by pultrusion-winding process using basalt fiber and epoxy resin, while FRP middle tube 3 is produced by vacuum-assisted resin transfer molding process using basalt fiber and epoxy resin.

[0155] The outer FRP tube body 7 has a thickness of 15mm and houses four distributed optical fiber sensing cables 18. The outer FRP tube body 7 comprises eight longitudinal fiber layups 16 and seven diagonal fiber layups 17, with the fiber directions of the seven diagonal fiber layups 17 forming an 86° angle with the longitudinal direction of the FRP outer tube 1. The outer FRP contact wall surface 6 has a thickness of 2mm and comprises two diagonal fiber layups 17 with the same fiber direction. The fiber direction of the outer FRP contact wall surface 6 is the same as that of the outer FRP ribs 5, both forming an 86° angle with the longitudinal direction of the FRP outer tube 1. The outer FRP ribs 5 have a rectangular cross-sectional shape and rotate along the outer FRP contact wall surface 6 in a three-wire unidirectional spiral pattern. The radial cross-sectional height of the outer FRP ribs 5 along the FRP outer tube 1 is 8mm, and the longitudinal cross-sectional width along the FRP outer tube 1 is 25mm. The net spacing between the outer FRP ribs 5 is 44.3mm.

[0156] The thickness of the middle tube FRP tube body 13 is 12 mm, in which 2 distributed optical fiber sensing cables 18 are arranged. The middle tube FRP tube body 13 comprises 5 layers of longitudinal fiber plies 16 and 6 layers of oblique fiber plies 17, and the fiber direction of the 6 layers of oblique fiber plies 17 is at an 86° angle with the longitudinal direction of the FRP middle tube 3. The thickness of the middle tube inner side FRP contact wall 12 and the middle tube outer side FRP contact wall 14 is 1 mm, and each comprises one layer of oblique fiber plies 17. The fiber direction of the middle tube inner side FRP contact wall 12, the middle tube outer side FRP contact wall 14, the middle tube inner side FRP rib 11 and the middle tube outer side FRP rib 15 is the same, and is at an 86° angle with the longitudinal direction of the FRP middle tube 3. The cross-sectional shape of the middle tube inner side FRP rib 11 and the middle tube outer side FRP rib 15 is rectangular, and is a three-wire single helix along the middle tube inner side FRP contact wall 12 and the middle tube outer side FRP contact wall 14, respectively. The cross-sectional height of the middle tube inner side FRP rib 11 and the middle tube outer side FRP rib 15 along the radial direction of the FRP middle tube 3 is 6 mm, and the cross-sectional width along the longitudinal direction of the FRP middle tube 3 is 20 mm. The rib-to-rib clear distance of the middle tube inner side FRP rib 11 is 31.4 mm, and the rib-to-rib clear distance of the middle tube outer side FRP rib 15 is 33.5 mm.

[0157] The thickness of the inner tube FRP tube body 8 is 10 mm, in which 4 distributed optical fiber sensing cables 18 are uniformly arranged. The inner tube FRP tube body 8 comprises 6 layers of longitudinal fiber plies 16 and 4 layers of oblique fiber plies 17, and the fiber direction of the 4 layers of oblique fiber plies 17 is at an 86° angle with the longitudinal direction of the FRP inner tube 2. The thickness of the inner tube FRP contact wall 9 is 2 mm, and it comprises two layers of oblique fiber plies 17 with the same fiber direction. The fiber direction of the inner tube FRP contact wall 9 is the same as that of the inner tube FRP rib 10, and is at an 86° angle with the longitudinal direction of the FRP inner tube 2. The cross-sectional shape of the inner tube FRP rib 10 is rectangular, and the rotation mode along the inner tube FRP contact wall 9 is a double-wire single helix. The cross-sectional height of the inner tube FRP rib 10 along the radial direction of the FRP inner tube 2 is 5 mm, and the cross-sectional width along the longitudinal direction of the FRP inner tube 2 is 20 mm. The rib-to-rib clear distance of the inner tube FRP rib 10 is 32.7 mm.

[0158] The core concrete 4 is filled between the FRP outer tube 1 and the FRP middle tube 3, and between the FRP middle tube 3 and the FRP inner tube 2, and the maximum particle size of the aggregate is 15 mm, and the strength grade is C40.

[0159] The manufacturing method of the high-bonding self-monitoring FRP tube concrete composite pile of the embodiment comprises the following steps:

[0160] (1) Determine the pile length, the cross-sectional shape and size of the pile body, and the maximum bending moment and shear force of the pile according to the design requirements.

[0161] (2) Determine the length of FRP outer tube 1, FRP inner tube 2 and FRP middle tube 3 according to the length of the pile.

[0162] (3) Determine the FRP tube concrete composite pile with one FRP outer tube 1, one FRP middle tube 3 and one FRP inner tube 2 according to the cross-sectional shape and size of the pile body and the maximum bending moment and shear force of the pile; further determine the cross-sectional shape of FRP outer tube 1, FRP inner tube 2 and FRP middle tube 3, the thickness and layer design scheme of outer tube FRP tube body 7, inner tube FRP tube body 8 and middle tube FRP tube body 13, the thickness and layer design scheme of outer tube FRP contact wall 6, inner tube FRP contact wall 9, middle tube inner side FRP contact wall 12 and middle tube outer side FRP contact wall 14, the rotation mode, cross-sectional shape, cross-sectional height, cross-sectional width, rib spacing and layer design scheme of each of outer tube FRP rib 5, inner tube FRP rib 10, middle tube inner side FRP rib 11 and middle tube outer side FRP rib 15, and the strength grade and mix design scheme of core concrete 4. Determine the number and position of distributed optical fiber sensing optical cable 18 in outer tube FRP tube body 7, inner tube FRP tube body 8 and middle tube FRP tube body 13 according to the monitoring requirements of the pile foundation. The parameters are as described above.

[0163] (4) In the factory, corresponding molds and inlays are made, and FRP outer tube 1 and FRP inner tube 2 are produced by pultrusion-winding process, and FRP middle tube 3 is produced by vacuum assisted resin transfer molding process.

[0164] (5) Use clean water to rinse the outer surface of the FRP outer tube and wipe it dry with gauze, use a brush to evenly apply the mixed high-strength epoxy resin adhesive on the outer surface of the FRP outer tube to make the adhesive thickness about 0.2mm-0.3mm, then immediately apply the weighed silica sand with particle size range of 1.18mm-2.36mm evenly in the adhesive layer, visually and manually control the uniformity of the sand layer, and then place the FRP outer tube indoors until the adhesive design curing time.

[0165] (6) Process and make positioning block 19 and packaging end plate 20, use positioning block 19 and high-strength adhesive to position and bond the relative positions of FRP outer tube 1, FRP inner tube 2 and FRP middle tube 3, and then use packaging end plate 20 and high-strength adhesive to seal the lower end surface of FRP outer tube 1, FRP inner tube 2 and FRP middle tube 3; wrap the exposed part of distributed optical fiber sensing optical cable 18 with bubble film, and then temporarily fix it at a suitable position on the surface of the FRP tube to prevent damage to the optical fiber during construction.

[0166] (7) Use lifting equipment to lift the FRP outer tube 1, FRP inner tube 2 and FRP middle tube 3 that have been sealed and bonded, and fix them in the vertical direction on the horizontal hardened ground with the help of temporary support members.

[0167] (8) Install the grouting conduit 21, taking care to avoid collisions between the grouting conduit 21 and the FRP outer pipe 1, FRP inner pipe 2, or FRP middle pipe 3. Pour the core concrete 4 into the area between the FRP outer pipe 1 and the FRP middle pipe 3, and between the FRP middle pipe 3 and the FRP inner pipe 2, vibrating the concrete while pouring to ensure the core concrete 4 is densely poured. After the core concrete 4 is poured, continue to vibrate the core concrete 4 to a depth of 2 meters below the pile top until the concrete stops settling and no more bubbles appear. Then smooth the concrete at the pile top. Cure in a temporary fixed position until the designed curing time for the concrete.

[0168] (9) Measure and locate the construction position of the composite pile at the construction site.

[0169] (10) Select a suitable drilling rig according to the construction site conditions to drill the pilot hole for the pile foundation at the pile location. The diameter of the pilot hole is 0.05 to 0.1 meters smaller than the pile diameter, and the depth of the pilot hole is 11 meters. Then, the pile driver is positioned, the FRP pipe concrete composite pile is lifted and aligned with the measured pile location and slowly lowered into the soil. A pile pad is placed between the pile top and the pile hammer, and the verticality of the pile body is corrected to within 0.5%. The pile hammer is used to lightly strike the top surface of the composite pile several times, so that the pile sinks into the soil 1 to 2 meters to reach a stable position. The horizontal deviation of the pile position and the verticality of the pile body are corrected again, and then the pile is driven at a uniform speed to the design elevation.

[0170] (11) After the pile driving is completed, check the horizontal deviation of the pile position and the elevation deviation of the pile top of the composite pile. Then, use optical fiber lead wires to connect the distributed optical fiber sensing cable to the distributed optical fiber demodulator.

[0171] Example 8

[0172] See Figure 20 , Figure 21 As shown, the high-bonding self-monitoring FRP pipe concrete composite pile of this embodiment includes an FRP outer pipe 1 with a rounded rectangular cross-section and a core concrete 4.

[0173] The pile body length is 4.0 m. The outer contour of the FRP outer tube 1 is 300 mm long and 240 mm wide, and is produced by basalt fiber and epoxy resin through pultrusion-winding process. The thickness of the outer tube FRP pipe body 7 is 8 mm, and 4 distributed optical fiber sensing cables 18 are uniformly arranged therein. The outer tube FRP pipe body 7 comprises 5 layers of longitudinal fiber plies 16 and 3 layers of oblique fiber plies 17, and the fiber direction of the 3 layers of oblique fiber plies 17 is at an angle of 86° with the longitudinal direction of the FRP outer tube 1. The thickness of the outer tube FRP contact wall 6 is 1 mm, which is composed of one layer of oblique fiber plies 17. The fiber direction of the outer tube FRP contact wall 6 is the same as that of the outer tube FRP rib 5, and is at an angle of 86° with the longitudinal direction of the FRP outer tube 1. The cross-sectional shape of the outer tube FRP rib 5 is rectangular, and the rotation mode along the outer tube FRP contact wall 6 is single-line unidirectional spiral. The cross-sectional height of the outer tube FRP rib 5 along the radial direction of the FRP outer tube 1 is 5 mm, and the cross-sectional width along the longitudinal direction of the FRP outer tube 1 is 20 mm. The rib clearance of the outer tube FRP rib 5 is 49.3 mm. The core concrete 4 is filled in the FRP outer tube 1, the maximum particle size of the aggregate is 15 mm, and the strength grade is C40.

[0174] Therefore, the present application adopts the above-mentioned high-bonding self-monitoring FRP pipe concrete composite pile and its manufacturing method, uses FRP pipe material with good corrosion resistance and sealing performance as the outer surface of the pile foundation, which can prevent the corrosion of the pile body by corrosive medium in the external environment and effectively delay the deterioration process of the pile foundation. The FRP rib arranged on the contact wall of the FRP pipe material and the concrete can significantly enhance the bonding performance of the FRP pipe material-concrete interface; the FRP contact wall with the same fiber direction as the FRP rib arranged on the surface of the FRP pipe material can reduce the production defects of the FRP pipe material and improve the shear resistance of the FRP rib, and the two mechanisms work together to make the composite pile fully exert the mechanical properties of the FRP pipe material during the stress process and improve the bearing capacity of the composite pile.

[0175] The FRP pipe material adopted by the present application comprises multiple layers of longitudinal fiber plies and multiple layers of oblique fiber plies, and by means of the good bonding performance of the FRP pipe material and the concrete interface, sufficient longitudinal and transverse constraints can be provided for the core concrete in the pipe, the FRP pipe material can fully replace the steel reinforcement in the pile foundation with lower bearing capacity requirements, and the FRP pipe material can also partially replace the steel reinforcement in the pile foundation with higher bearing capacity requirements, thereby reducing the manufacturing and installation requirements of the steel reinforcement cage, improving the construction speed, and reducing the construction cost and the life cycle carbon emissions of the pile foundation. The sand-bonding treatment on the outer surface of the FRP outer tube can significantly improve the pile side friction resistance of the FRP pipe concrete composite pile, and further improve the bearing capacity of the FRP pipe concrete composite pile. By arranging the distributed optical fiber sensing cable in the FRP pipe material, the real-time monitoring of the service state of the FRP pipe concrete composite pile can be realized, and the use safety of the structure can be effectively ensured.

[0176] It should be pointed out finally that the above examples are only used to illustrate the technical solutions of the present application but not to limit it, and although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can still be modified or replaced equivalently, and these modifications or equivalent replacements should not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A high-bond self-monitoring FRP pipe concrete composite pile, characterized in that: It includes an FRP outer tube, an FRP middle tube, an FRP inner tube, and core concrete. The core concrete, FRP inner tube, and FRP middle tube are all located inside the FRP outer tube. The FRP outer tube, from the inside out, includes an outer tube FRP rib, an outer tube FRP contact wall, and an outer tube FRP body. The FRP inner tube, from the inside out, includes an inner tube FRP body, an inner tube FRP contact wall, and an inner tube FRP rib. The FRP middle tube, from the inside out, includes a middle tube inner FRP rib, a middle tube inner FRP contact wall, a middle tube FRP body, a middle tube outer FRP contact wall, and a middle tube outer FRP rib.

2. The high-bond self-monitoring FRP pipe concrete composite pile according to claim 1, characterized in that: The outer tube FRP body, inner tube FRP body, and middle tube FRP body all include multiple longitudinal fiber lay-ups, multiple oblique fiber lay-ups, and distributed optical fiber sensing cables. The distributed optical fiber sensing cables are laid longitudinally within the longitudinal fiber lay-ups, and the angle between the fiber direction of the oblique fiber lay-ups and the longitudinal direction of the outer tube FRP body is (75°, 90°).

3. The high-bond self-monitoring FRP pipe concrete composite pile according to claim 2, characterized in that: Both the outer tube FRP contact wall and the inner tube FRP contact wall are provided with several layers of oblique fiber lay-up in the same fiber direction. The outer surface of the outer tube FRP contact wall and the inner surface of the inner tube FRP contact wall are respectively attached with outer tube FRP ribs and inner tube FRP ribs. The fiber direction of the inner tube FRP ribs and the outer tube FRP ribs is the same as that of the inner tube FRP contact wall and the outer tube FRP contact wall, respectively.

4. The high-bond self-monitoring FRP pipe concrete composite pile according to claim 3, characterized in that: Both the inner and outer FRP contact walls of the tube include several layers of oblique fiber lay-ups with the same fiber direction. Both the inner and outer FRP contact walls of the tube are equipped with FRP ribs. The fiber direction of the inner FRP contact wall is the same as that of the inner FRP rib, and the fiber direction of the outer FRP contact wall is the same as that of the outer FRP rib.

5. A high-bond self-monitoring FRP pipe concrete composite pile according to claim 4, characterized in that: The outer tube FRP rib, inner tube FRP rib, inner side FRP rib of the middle tube, and outer side FRP rib of the middle tube rotate along the outer tube FRP contact wall, inner tube FRP contact wall, inner side FRP contact wall, and outer side FRP contact wall of the middle tube, respectively. The rotation method is a single-line unidirectional spiral or a multi-line unidirectional spiral.

6. The high-bond self-monitoring FRP pipe concrete composite pile according to claim 5, characterized in that: The distances between adjacent FRP outer and inner pipes, between adjacent FRP outer and middle pipes, and between adjacent FRP middle and inner pipes shall not be less than 4 times the maximum aggregate size in the core concrete, and shall not be less than 80 mm.

7. A high-bond self-monitoring FRP pipe concrete composite pile according to claim 6, characterized in that: The thickness of the outer FRP tube, inner FRP tube, and middle FRP tube is not less than 4mm. Simultaneously, the outer surface of the FRP outer tube is treated with a high-strength adhesive with a tensile strength of not less than 30MPa and silica sand. The particle size of the silica sand used ranges from 0.60mm to 4.00mm, and the surface density of the silica sand layer on the outer surface after the sand-bonding treatment is 900g / m³. 2 -1600g / m 2 .

8. A high-bond self-monitoring FRP pipe concrete composite pile according to claim 7, characterized in that: The configuration of the outer tube FRP ribs, inner tube FRP ribs, inner side FRP ribs of the middle tube, and outer side FRP ribs of the middle tube shall comply with the following provisions: h r ≥3mm h r ≥0.25×t b h r ≥0.009×h max s r ≤100mm s r ≤0.3×h min i r ≥45° Where: h r t is the cross-sectional height of the FRP rib along the radial direction of the pipe body. b The wall thickness of the FRP pipe is equal to the sum of the pipe body thickness and the wall thickness; h max h is the maximum outer contour dimension of the FRP pipe cross-section; min The minimum outer contour dimension of the FRP pipe cross-section; w r The width of the FRP rib along the longitudinal direction of the pipe body is s. n The net distance between FRP ribs along the longitudinal direction of the tube body; s r The spacing of the FRP ribs along the longitudinal direction of the pipe body is s. r =w r +s n ;θ r It is the angle between the side of the FRP rib and the longitudinal direction of the tube body.

9. A method for manufacturing a high-bond self-monitoring FRP tube concrete composite pile, using the high-bond self-monitoring FRP tube concrete composite pile described in any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Determine the pile length, cross-sectional shape and dimensions, and maximum bending moment and shear force on the pile according to the design requirements; Step 2: Determine the lengths of the FRP outer pipe, FRP inner pipe, and FRP middle pipe based on the pile length; Step 3: Determine whether to install FRP inner tube and FRP middle tube based on the cross-sectional shape and size of the pile body and the maximum bending moment and shear force on the pile, and determine the internal design of FRP outer tube, FRP inner tube and FRP middle tube, the strength grade and mix ratio of core concrete, and the number and location of distributed optical fiber sensing cables in the FRP outer tube, FRP inner tube and FRP middle tube. Step 4: Fabricate the corresponding molds and inserts, and use pultrusion-winding, pultrusion-braiding-winding or vacuum-assisted resin transfer molding processes to prepare FRP outer tubes, FRP inner tubes and FRP middle tubes; Step 5: Rinse the outer surface of the FRP outer tube with clean water and wipe it dry with gauze. Apply high-strength adhesive evenly to the outer surface of the FRP outer tube, and then apply the weighed silica sand evenly to the adhesive layer. Let the FRP outer tube stand indoors until the adhesive has cured for the designed time. Step 6: Process the positioning block and the encapsulation end plate to position and fix the relative positions of the FRP outer tube, FRP inner tube and FRP middle tube. Use the encapsulation end plate and high-strength adhesive to seal the lower end faces of the FRP outer tube, FRP inner tube and FRP middle tube. Step 7: Use lifting equipment to lift the sealed and bonded FRP outer pipe, FRP inner pipe and FRP middle pipe, and use temporary support components to fix them vertically on the horizontal hardened ground. Step 8: Install the grouting conduit and pour core concrete into the areas between adjacent FRP outer and inner pipes, between adjacent FRP outer and middle pipes, between adjacent FRP middle and inner pipes, inside the FRP outer pipe, and inside the FRP middle pipe. Vibrate the concrete while pouring. After the core concrete is poured, continue to vibrate the core concrete up to 2 meters below the pile top until the concrete stops settling and stops bubbling. Then smooth the concrete at the top of the pile and cure it in a temporary fixed position until the designed curing time for the concrete is reached. Step 9: Measure and locate the composite piles at the construction site; Step 10: Lift the FRP pipe concrete composite pile after maintenance, align it with the measured pile position and drive the pile. When the pile diameter is less than 0.6 meters, it is advisable to directly use the hammer driving method to drive the pile. When the pile diameter is greater than 0.6 meters, a pile foundation pilot hole can be pre-drilled at the pile position and then the hammer driving method can be used to drive the pile. Step 11: After the pile driving is completed, use fiber optic leads to connect the distributed fiber optic sensing cable to the distributed fiber optic demodulator.

10. The method for manufacturing a high-bond self-monitoring FRP pipe concrete composite pile according to claim 9, characterized in that: Step 3 involves the internal design of the FRP outer tube, FRP inner tube, and FRP middle tube, including the cross-sectional shape of the FRP outer tube, FRP inner tube, and FRP middle tube; the thickness and layup design scheme of each of the FRP tube bodies; the thickness and layup design scheme of each of the FRP contact walls of the outer tube, inner tube, inner FRP contact walls, and outer FRP contact walls of the middle tube; and the rotation method, cross-sectional shape, cross-sectional height, cross-sectional width, net spacing between ribs, and layup design scheme of each of the FRP ribs of the outer tube, inner tube, inner FRP rib, and outer FRP rib.

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