Composite uplift-resistant repairing, reinforcing and reconstructing structure for existing pipe pile
By drilling a hole in the center of the pile and inserting a composite anti-uplift and buoyancy component, the problem of reinforcement of existing building pile foundations after an anti-uplift accident is solved, the compressive and tensile functions are restored, construction costs and difficulties are reduced, and it is environmentally friendly and controllable.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIAN YAN FOUND ENG
- Filing Date
- 2025-05-21
- Publication Date
- 2026-05-15
AI Technical Summary
After an uplift accident, conventional reinforcement methods for existing building pile foundations consume large amounts of steel and concrete, are difficult to construct, have long construction periods, and cause serious pollution, and cannot effectively solve the problems of compressive and uplift resistance.
By drilling a core sample at the center of the pile, a composite anti-uplift and buoyancy component, including cement grout and steel pipe, is implanted. High-pressure directional injection of cement grout is performed, and steel strands are implanted. The steel strands are then fixed to the pile cap with anchors to form a composite anti-uplift and buoyancy structure.
This method restores the compressive and tensile strength of existing pipe piles, reduces construction costs and difficulty, reduces carbon emissions, simplifies the process, and improves the controllability and environmental friendliness of construction.
Smart Images
Figure CN224243972U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of building reinforcement technology, and in particular provides a composite anti-uplift and buoyancy repair, reinforcement and reconstruction structure for existing pipe piles. Background Technology
[0002] Pile foundations are a common type of foundation used in buildings. They bear the loads of the superstructure, thus solving problems such as insufficient bearing capacity and excessive deformation of the building's foundation. In recent years, due to urban flooding caused by extreme rainfall and floods, rising groundwater levels, or insufficient anti-buoyancy design, some existing buildings using pile foundations have experienced anti-buoyancy accidents, causing significant economic losses and social impact, attracting widespread attention. Besides issues such as overall or partial uplift of the underground structure, foundation voids, and structural damage and cracking, these existing buildings may also experience pile fractures or even breakage under uplift forces if the pile foundation's uplift bearing capacity is not adequately considered.
[0003] After an existing building with pile foundation experiences a buoyancy accident, its reinforcement treatment, in addition to verifying the compressive bearing capacity, should also involve redesigning the foundation and superstructure for buoyancy based on the new buoyancy design water level. The conventional approach is to grout and reinforce the existing piles on the outside to meet the compressive bearing capacity requirements; or to add tension piles or tension anchors. If the reinforced existing pile foundation does not meet the compressive bearing capacity requirements, then additional piles that are both compressive and tension anchors are added. Both adding piles and using tension anchors require significant additional consumption of steel and concrete, increasing carbon emissions. Furthermore, pile driving equipment is difficult to operate in confined spaces, has a long construction period, high costs, and causes severe on-site mud pollution. Summary of the Invention
[0004] Based on this, the present invention provides a composite anti-uplift and buoyancy repair and reinforcement reconstruction method and structure for existing pipe piles, so as to reconstruct defective compression piles into qualified compression and uplift piles, and has the characteristics of simple construction process, feasible in confined space, economic and environmental protection.
[0005] On the one hand, this utility model provides a composite anti-pull-out buoyancy repair, reinforcement and reconstruction method for existing pipe piles, including: drilling a core along the vertical center of the pipe pile body to test the integrity of the pile body and find existing cracks, fissures and other problems; implanting a composite anti-pull-out buoyancy component into the core hole; and using a high-pressure directional grouting pipe to inject cement grout into the core hole of the pipe pile under high pressure and direction.
[0006] Furthermore, a steel pipe is embedded in the middle of the pipe pile, and cement grout is injected into the steel pipe; cement grout is then injected into the annulus between the core hole of the pipe pile and the steel pipe through a high-pressure directional grouting pipe to repair and reinforce the pipe pile body.
[0007] Furthermore, the cement grout in the pipe pile is injected under high pressure using a high-pressure directional grouting pipe, and ordinary grouting pipes are used to reinforce the outside of the pile according to the condition of the pile body. A centering support is set on the outside of the steel pipe to keep the anti-pull-out component in the center of the cement grout.
[0008] Furthermore, a concrete cushion layer, a waterproof membrane, and a fine aggregate concrete protective layer are installed on the upper part of the pipe pile; the top of the steel pipe is higher than the fine aggregate concrete protective layer, the waterproof membrane is wrapped around the steel pipe, and it is tightened with metal pipe clamps.
[0009] Furthermore, the steel pipe is partially reinforced with polymer mortar in the concrete cushion layer, and a cement-based penetrating crystallizer is set at the bottom of the polymer mortar. An additional layer of waterproof membrane is set at the junction with the waterproof membrane, and a high-elasticity rubber asphalt waterproof coating is set on the top of the waterproof membrane at the junction to form a waterproof joint.
[0010] For piles exhibiting anti-uplift and buoyancy issues, a core sampling method is employed at the pile center to detect defects such as cracks and fissures in the pile body. A high-pressure directional method is then used within the core sampling hole to repair and reinforce the pile body, restoring its compressive strength.
[0011] Furthermore, steel strands are installed in the steel pipe, with the upper part of the steel strands extending above the steel pipe. These strands are then fixed to the pile cap by anchors and anchor plates, thus transforming the existing compression-resistant pipe piles into compression-resistant and tension-resistant piles.
[0012] Furthermore, the cement grout in the steel pipe is fully filled, partially filled, or unfilled, and the bonding relationship between the steel strands and the cement grout in the steel pipe corresponds to the fully bonded type, partially bonded type, and unbonded type.
[0013] Furthermore, the unbonded steel strands of the reinforcing bar are fixed to the steel pipe at the bottom end with anchors and anchor plates, and the top end of the steel strands is directly fixed to the bearing platform with anchors; and / or, the top end of the steel strands is prestressed and then fixed to the bearing platform with anchors.
[0014] Furthermore, the pipe pile is a pipe pile. The concrete in the central hole of the pipe pile is removed, and the integrity of the pipe pile is checked. A steel pipe is inserted into the central hole, and cement grout is injected between the pipe pile and the steel pipe through a high-pressure directional grouting pipe. A steel strand is inserted into the steel pipe, so that the upper end of the steel strand is higher than the steel pipe, and the upper end of the steel strand is fixed to the pile cap by anchors and anchor plates. Cement grout is then injected into the steel pipe to fix the lower end of the steel strand. Because the pipe pile has a central hole, after removing the concrete from the central hole, it is more convenient to check the integrity of the pipe pile and find defects or cracks through the central hole.
[0015] The structure involved in anti-uplift and buoyancy mainly includes steel pipes, cement grout, steel strands, centering supports, anchor plates, and anchorages. High-pressure injection of cement grout is used to repair and reinforce the defects in the pile body. Then, steel pipes are inserted into the cement grout, with steel strands inserted into the steel pipes and cement grout poured in for fixation. Centering supports are set on both sides of the steel pipes to ensure that they are located in the middle of the cement grout. The upper part of the steel strands is higher than the steel pipes and is fixed in the pile cap through anchorages and anchor plates, thus enabling the existing compression pipe piles to also have the function of anti-uplift and buoyancy.
[0016] On the other hand, this utility model provides a composite anti-uplift and buoyancy repair, reinforcement and reconstruction structure for existing pipe piles. The composite anti-uplift and buoyancy repair, reinforcement and reconstruction method for existing pipe piles includes drilling a core hole in the pipe pile, and a composite anti-uplift and buoyancy component is provided in the core hole; the composite anti-uplift and buoyancy component includes cement grout, steel pipe and steel strand.
[0017] The cement grout is formed by high-pressure directional injection into the core hole of the pipe pile through a high-pressure directional grouting pipe; the steel pipe is buried in the middle of the pipe pile, and the annulus between the central core hole and the steel pipe is fixed by the cement grout; in the steel strand insertion steel pipe, the upper part of the steel strand is higher than the steel pipe and is fixed in the pile cap by anchors and anchor plates.
[0018] The steel pipe is not filled with cement grout. The bonding relationship between the steel strands and the cement grout in the steel pipe is that the reinforcing bars are unbonded. The steel strands are fixed to the steel pipe at the bottom with anchors and anchor plates. The top of the steel strands is directly fixed to the bearing platform with anchors, or the top of the steel strands is prestressed and then fixed to the bearing platform with anchors.
[0019] The provided composite anti-uplift and buoyancy repair, reinforcement, and reconstruction method and structure for existing pipe piles have technical advantages in at least the following aspects:
[0020] On the one hand, the defects in the pile body are repaired by directional high-pressure grouting after core sampling, thus restoring the compressive strength of the existing pipe pile.
[0021] On the other hand, by implanting composite anti-uplift components through core holes, the anti-uplift function is added, and the defective compression piles are reconstructed into qualified compression and uplift piles. This solves both compression and uplift problems and overcomes the disadvantages of additional compression piles, uplift piles or uplift anchors, and additional uplift measures, such as large steel and concrete usage, high cost, large equipment size, complex construction procedures, mud pollution, and long construction period. It has the advantages of relatively low construction cost, simple construction process, small equipment size, feasible in confined space, controllable quality, time saving, and green, low-carbon and environmentally friendly, and has good engineering application value and prospects for promotion and application. Attached Figure Description
[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The accompanying drawings, which are provided to further illustrate the present invention and constitute a part of this application, do not constitute an undue limitation of the present invention.
[0023] Figure 1 This is a longitudinal sectional view of a preferred embodiment of a composite anti-uplift and buoyancy repair, reinforcement, and reconstruction structure for existing pipe piles.
[0024] Figure 2 yes Figure 1 The diagram shows a radial cross-section of the composite anti-uplift and buoyancy repair and reinforcement reconstruction structure of the pipe pile.
[0025] Figure 3 yes Figure 1 The diagram shows a partially enlarged schematic of the composite anti-uplift and buoyancy repair, reinforcement, and reconstruction structure of the pipe pile.
[0026] Figure 4 This is a schematic diagram illustrating the process of composite anti-uplift and buoyancy repair, reinforcement, and reconstruction of existing pipe piles.
[0027] In the diagram, 1-pipe pile, 2-cement grout, 3-steel pipe, 4-steel strand, 5-centering support, 6-concrete cushion layer, 7-waterproof membrane, 8-waterproof membrane supplementary layer, 9-cement-based penetrating crystallization, 10-polymer mortar, 11-high-elasticity rubber asphalt waterproof coating, 12-fine stone concrete protective layer, 13-metal pipe clamp, 14-anchor, 15-anchor plate, 16-pile cap, 17-high-pressure directional grouting pipe, 18-ordinary grouting pipe, 19-core hole, 20-existing reinforcing steel, 21-existing pile body concrete. Detailed Implementation
[0028] In recent years, due to urban flooding caused by extreme rainfall and floods, rising groundwater levels, or insufficient anti-buoyancy design, some existing buildings using pile foundations have experienced anti-buoyancy accidents, causing significant economic losses and social impact, which has attracted widespread attention. Besides issues such as overall or partial uplift of the underground structure, foundation voids, and structural damage and cracking, these existing buildings may also experience pile fractures or even breakage under uplift forces if the pile foundation's uplift bearing capacity is not adequately considered.
[0029] After an existing building with pile foundation experiences a buoyancy accident, its reinforcement treatment, in addition to verifying the compressive bearing capacity, should also involve redesigning the foundation and superstructure for buoyancy based on the new buoyancy design water level. The conventional approach is to grout and reinforce the existing piles on the outside to meet the compressive bearing capacity requirements; or to add tension piles or tension anchors. If the reinforced existing pile foundation does not meet the compressive bearing capacity requirements, then additional piles that are both compressive and tension anchors are added. Both adding piles and using tension anchors require significant additional consumption of steel and concrete, increasing carbon emissions. Furthermore, pile driving equipment is difficult to operate in confined spaces, has a long construction period, high costs, and causes severe on-site mud pollution.
[0030] To address this issue, this invention provides a composite anti-uplift and buoyancy repair and reinforcement reconstruction method and structure for existing pipe piles. The method involves core drilling to inspect the integrity of the pipe pile, revealing cracks and fissures. A composite anti-uplift and buoyancy component is implanted into the core hole. This component comprises cement grout, a steel pipe, and steel strands. The cement grout is formed by high-pressure directional injection into the core hole of the pipe pile via a high-pressure directional grouting pipe. The steel pipe is embedded in the middle of the pipe pile and fixed by cement grout filling. The annulus between the central core hole and the steel pipe is also fixed by cement grout. The steel strands are inserted into the steel pipe and fixed by cement grout filling. The upper part of the steel strands extends above the steel pipe and is fixed to the pile cap by anchors and anchor plates. This method and structure reconstruct defective compression piles into qualified compression and uplift piles, simultaneously solving both compression and uplift / buoyancy problems. It also features simple construction technology, feasibility in confined spaces, and economic and environmental benefits.
[0031] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. The description of exemplary embodiments is merely illustrative and is in no way intended to limit this disclosure or its application or use. This disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully express the scope of this disclosure to those skilled in the art.
[0032] like Figures 1 to 4 As shown, this utility model provides a composite anti-pull-out buoyancy repair, reinforcement and reconstruction method for existing pipe piles, including: drilling a core along the vertical center of the pipe pile 1 to test the integrity of the pile body and find existing cracks, fissures and other problems; implanting a composite anti-pull-out buoyancy component into the core hole 19; and using a high-pressure directional grouting pipe 17 to inject cement grout 2 into the core hole 19 of the pipe pile 1 under high pressure and direction.
[0033] During implementation, a steel pipe 3 is buried in the middle of the pipe pile 1, and cement grout 2 is injected into the steel pipe 3; cement grout 2 is injected into the annulus between the core hole 19 of the pipe pile 1 and the steel pipe through the high-pressure directional grouting pipe 17 to repair and reinforce the pile body of the pipe pile 1.
[0034] The cement grout 2 in the pipe pile 1 is injected under high pressure using a high-pressure directional grouting pipe 17, and a regular grouting pipe 18 is used to reinforce the outside of the pile according to the condition of the pile body. A centering support 5 is set on the outside of the steel pipe 1 to keep the anti-pull-out component in the center of the cement grout 2.
[0035] Furthermore, a concrete cushion layer 6, a waterproof membrane 7, and a fine aggregate concrete protective layer 12 are installed on the upper part of the pipe pile 1; the top of the steel pipe 3 is higher than the fine aggregate concrete protective layer 12, the waterproof membrane 7 is wrapped around the steel pipe 3, and tightened with a metal pipe clamp 13. The steel pipe 3 is partially reinforced in the concrete cushion layer 6 with polymer mortar 10, and a cement-based penetrating crystallizer 9 is installed below the polymer mortar 10. An additional waterproof membrane layer 8 is installed at the junction with the waterproof membrane 7, and a high-elasticity rubber asphalt waterproof coating waterproof layer 11 is installed on the upper part of the waterproof membrane 7 at the junction to form a waterproof joint.
[0036] Furthermore, in the preferred embodiment, a steel strand 4 is installed in the steel pipe 3, with the upper part of the steel strand 4 extending above the steel pipe 3. It is fixed to the pile cap 16 by the anchor 14 and the anchor plate 15, so that the existing pressure-resistant pipe pile is repaired, reinforced, and reconstructed into a pressure-resistant and tension-resistant pile.
[0037] The cement grout 2 in the steel pipe 3 can be fully filled, partially filled, or unfilled. The bonding relationship between the steel strands 4 and the cement grout 2 in the steel pipe 3 corresponds to the fully bonded, partially bonded, and unbonded types. The unbonded steel strands 4 are fixed to the steel pipe 3 at the bottom end with anchors 14 and anchor plates 15. The top end of the steel strands 4 is directly fixed to the bearing platform 16 with anchors 14; and / or, the top end of the steel strands 4 is prestressed and then fixed to the bearing platform 16 with anchors 14.
[0038] By repairing pile defects through directional high-pressure grouting after core sampling, the compressive strength of existing pipe piles is restored. Composite tensile strength components are then implanted through the core sampling holes to add tensile strength, thus reconstructing defective compressive piles into qualified compressive and tensile piles. This simultaneously solves the problems of compressive and tensile strength, overcoming the disadvantages of additional compressive piles, tensile piles, or tensile anchors, as well as additional tensile strength measures, which involve large amounts of steel and concrete, high costs, large equipment size, complex construction procedures, mud pollution, and long construction periods. It has the advantages of relatively low construction cost, simple construction process, compact equipment size, feasibility in confined spaces, controllable quality, time saving, and green, low-carbon and environmentally friendly features, and has good engineering application value and prospects for promotion and application.
[0039] Another aspect of this utility model provides a composite anti-uplift and buoyancy repair, reinforcement, and reconstruction structure for existing pipe piles. The method for this composite anti-uplift and buoyancy repair, reinforcement, and reconstruction includes drilling a core hole 19 in the pipe pile 1. A composite anti-uplift and buoyancy component is installed within the core hole 19. The composite anti-uplift and buoyancy component includes cement grout 2, a steel pipe 3, and steel strands 4. The cement grout 2 is formed by high-pressure directional injection into the core hole 19 of the pipe pile 1 via a high-pressure directional grouting pipe 17. The steel pipe 3 is embedded in the middle of the pipe pile 1, and the annulus between the central core hole 19 and the steel pipe is fixed by the cement grout 2. The steel strands 4 are inserted into the steel pipe 3, with the upper part of the steel strands 4 extending above the steel pipe 3, and are fixed to the foundation 16 by anchors 14 and anchor plates 15.
[0040] During implementation, the cement grout 2 in the steel pipe 3 can be fully filled, partially filled, or unfilled. The bonding relationship between the steel strands 4 and the cement grout 2 in the steel pipe 3 corresponds to the fully bonded type, partially bonded type, and unbonded type. The unbonded type of steel strands 4 are fixed to the steel pipe 3 at the bottom end with anchors 14 and anchor plates 15, and the top end of the steel strands 4 is directly fixed to the bearing platform 16 with anchors 14; and / or, the top end of the steel strands 4 is prestressed and then fixed to the bearing platform 16 with anchors 14.
[0041] In some embodiments, the steel pipe 3 is not filled with cement grout 2, and the bonding relationship between the steel strand 4 and the cement grout 2 in the steel pipe 3 is a non-bonded type of bar reinforcement. The steel strand 4 and the steel pipe 3 are fixed at the bottom end with anchors 14 and anchor plates 15. The top end of the steel strand 4 is directly fixed to the bearing platform 16 with anchors 14, or the top end of the steel strand 4 is prestressed and then fixed to the bearing platform 16 with anchors 14.
[0042] Regarding compressive strength, for the pipe pile 1 that has problems with pull-out and buoyancy, the pile center core drilling method is used to detect defects such as cracks and fissures in the pile body; the high-pressure directional method in the core hole is used to repair and reinforce the defects such as cracks and fissures in the pile body of the pipe pile 1, and restore the compressive strength function of the pipe pile 1.
[0043] Regarding resistance to pull-out and buoyancy, as shown in the attached document... Figure 1 , Figure 2 and Figure 3 As shown, the anti-uplift device mainly includes: steel pipe 3, cement grout 2, steel strand 4, centering support 5, anchor plate 15, and anchor 14. The pile defects of pile 1 are repaired and reinforced by high-pressure injection of cement grout 2. Then, steel pipe 3 is inserted into cement grout 2. Steel strand 4 is inserted into steel pipe 3 and cement grout 2 is poured in to fix it. Centering supports 5 are set on both sides of steel pipe 3 to ensure that it is located in the middle of cement grout 2. The upper part of steel strand 4 extends above steel pipe 3 and is fixed in pile cap 16 through anchor 14 and anchor plate 15, so that the existing compression pipe pile can also have the function of anti-uplift.
[0044] Compared with traditional solutions, this utility model solves the problems of cost, construction period, environmental protection and construction difficulty of reconstructing anti-uplift piles or anti-buoyancy anchors and other anti-uplift and buoyancy structures. It has the advantages of relatively low construction cost, simple construction process, small equipment size, feasible in confined space, controllable quality, time saving, green and low-carbon environmental protection, and has good engineering application value and prospects for promotion and application.
[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.
Claims
1. A composite anti-uplift and buoyancy repair, reinforcement, and reconstruction structure for existing pipe piles, characterized in that, Includes a core hole (19) drilled in the pipe pile (1), wherein a composite anti-pull-out buoyancy component is provided in the core hole (19); The composite anti-pull-out component includes cement grout (2), steel pipe (3) and steel strand (4). The steel pipe (3) is embedded in the middle of the pipe pile (1), and the annular space between the central core hole (19) and the steel pipe (3) is fixed by cement grout (2); In the steel strand (4) inserted into the steel pipe (3), the upper part of the steel strand (4) is higher than the steel pipe (3) and is fixed in the bearing platform (16) by the anchor (14) and the anchor plate (15); The steel pipe (3) is not filled with cement grout (2), and the bonding relationship between the steel strand (4) and the cement grout (2) in the steel pipe (3) is that the reinforcing bar is unbonded. The steel strand (4) and the steel pipe (3) are fixed at the bottom end with anchor (14) and anchor plate (15). The cement grout (2) in the pipe pile (1) is injected under high pressure using a high-pressure directional grouting pipe (17), and a regular grouting pipe (18) is used to reinforce the outside of the pile according to the condition of the pile body. A centering bracket (5) is set on the outside of the steel pipe (1) to keep the anti-pull-out component in the center of the cement grout (2).
2. The composite anti-uplift and buoyancy repair, reinforcement, and reconstruction structure for existing pipe piles according to claim 1, characterized in that, The top end of the steel strand (4) is directly fixed to the bearing platform (16) by an anchor (14), or the top end of the steel strand (4) is prestressed and then fixed to the bearing platform (16) by an anchor (14).
3. The composite anti-uplift and buoyancy repair, reinforcement, and reconstruction structure for existing pipe piles according to claim 1, characterized in that, The cement grout (2) is formed by high-pressure directional injection of the high-pressure directional grouting pipe (17) into the core hole (19) of the pipe pile (1).
4. The composite anti-uplift and buoyancy repair, reinforcement, and reconstruction structure for existing pipe piles according to claim 1, characterized in that, A steel pipe (3) is embedded in the middle of the pipe pile (1), and cement grout (2) is injected into the steel pipe (3); cement grout (2) is injected into the annulus between the core hole (19) of the pipe pile (1) and the steel pipe through the high-pressure directional grouting pipe (17) to repair and reinforce the pile body of the pipe pile (1).
5. The composite anti-uplift and buoyancy repair, reinforcement, and reconstruction structure for existing pipe piles according to claim 1, characterized in that, The upper part of the pipe pile (1) is provided with a concrete cushion layer (6), a waterproof membrane (7) and a fine stone concrete protective layer (12); the top of the steel pipe (3) is higher than the fine stone concrete protective layer (12), the waterproof membrane (7) is wrapped around the steel pipe (3) and tightened with a metal pipe clamp (13).
6. The composite anti-uplift and buoyancy repair, reinforcement, and reconstruction structure for existing pipe piles according to claim 5, characterized in that, The steel pipe (3) is partially reinforced in the concrete cushion layer (6) with polymer mortar (10). Cement-based penetrating crystallizer (9) is set at the bottom of the polymer mortar (10), and an additional layer of waterproof membrane (8) is set at the junction with the waterproof membrane (7). A high-elasticity rubber asphalt waterproof coating waterproof layer (11) is set on the top of the waterproof membrane (7) at the junction to form a waterproof node.
7. The composite anti-uplift and buoyancy repair, reinforcement, and reconstruction structure for existing pipe piles according to any one of claims 1-6, characterized in that, A steel strand (4) is installed in the steel pipe (3). The upper part of the steel strand (4) is higher than the steel pipe (3) and is fixed in the pile cap (16) by the anchor (14) and the anchor plate (15), so that the existing pressure-resistant pipe pile is repaired, reinforced and reconstructed into a pressure-resistant and tension-resistant pile.
8. The composite anti-uplift and buoyancy repair, reinforcement, and reconstruction structure for existing pipe piles according to claim 7, characterized in that, The cement grout (2) in the steel pipe (3) is fully filled, partially filled or unfilled. The bonding relationship between the steel strand (4) in the steel pipe (3) and the cement grout (2) is as follows: fully bonded, partially bonded and unbonded.
9. The composite anti-uplift and buoyancy repair, reinforcement, and reconstruction structure for existing pipe piles according to claim 7, characterized in that, The unbonded steel strand (4) and the steel pipe (3) are fixed at the bottom end with anchor (14) and anchor plate (15), and the top end of the steel strand (4) is directly fixed to the bearing platform (16) with anchor (14); and / or, the top end of the steel strand (4) is prestressed and then fixed to the bearing platform (16) with anchor (14).