Pressure type precast pile structure

Abstract

The utility model discloses a pressure type precast pile structure, which is applied to uplift pile engineering in the anti-floating field and comprises a pile body structure, an end plate, a prestressed tendon rod body, a locking device and a pile tip. The pile body structure is a cylinder structure made of a reinforced concrete material, and the center of the pile body structure is a longitudinal through inner cavity; the end plates are metal steel plates and arranged at the two ends of the pile body structure. The prestressed tendon locking devices are located at the two ends of the pile body structure and can fix the prestressed tendon rod body and lock the pretensioning force borne by the prestressed tendon rod body to the end plates. The pile tip is of a conical structure formed by rolling a metal plate and is welded to the bottom of the pile body structure. Through mutual cooperation of the components, the pressure type precast pile structure which is internally provided with the prestressed tendon rod body and locks prestress borne by the prestressed tendon rod body at the two ends of the pile body structure is formed, and the problems that a conventional precast pipe pile is low in single pile bearing capacity, cracks are prone to being generated, durability is poor, and confined water cannot be resisted are solved.

Description

Technical Field

[0001] The utility model relates to a prefabricated pile structure, in particular to a pressure-type prefabricated pile structure, which is applied to an anti-pulling pile project in the anti-floating field. Background Art

[0002] In order to make full use of land resources, on the one hand, the main buildings on the ground are developing towards high-rise, and on the other hand, the development and utilization of underground space is also increasing. There are more and more underground projects such as high-rise building basements, pure underground garages, underground shopping malls, sunken squares, underground storage, underground transportation, etc. The utilization of underground space basically faces the problem of anti-floating, and certain anti-floating measures need to be taken. At present, there are many anti-floating measures used in China, which can be generally divided into two categories: active anti-floating (such as drainage decompression, curtain water isolation, etc.) and passive anti-floating (such as weight method, pull-out piles, anti-floating anchor rods, structural counterweights, etc.). Among the many anti-floating technologies, pull-out piles are widely used due to their good adaptability to the stratum and high pull-out bearing capacity, and the application market is broad. Pull-out piles can be divided into cast-in-place concrete pull-out piles and prefabricated pull-out piles according to their pile body materials; they can be divided into tension pull-out piles and pressure pull-out piles according to the acceptance mechanism. Prefabricated pull-out piles have been used in more and more projects because of their reliable construction quality and compliance with the national building energy conservation and green development direction. However, conventional prefabricated pull-out piles are subjected to tension, that is, the pull-out piles are subjected to tension at the top of the piles. In the subsequent working state, the pile body concrete is in a "stretched and contracted" state, with limited bearing capacity and prone to cracks. During the working stage, the pressure-type pull-out pile applies pressure to the pile body through the pile body force transmission components, so that the pile body concrete is continuously in a compressive stress working state under the working state, thereby keeping the cracks in the pile body in a controllable state, and being able to mobilize the deep soil to improve the pull-out bearing capacity of the single pile.

[0003] In recent years, more and more pressure-type prefabricated pile structures have appeared, but there has been no in-depth research on the durability of pressure-type piles, especially the protection of prestressed tendons in pressure-type piles. In addition, for high-pressure water strata, underground pressurized water upwelling often occurs due to the hollow inner cavity of the pipe piles themselves and the loose connections between other components, which seriously affects the construction work surface.

[0004] In view of the limited forms of existing precast pile structures, it is impossible to form precast piles with good durability and suitable for high-pressure water. A pressure-type precast pile structure is proposed to solve the above problems. Utility Model Content

[0005] The utility model aims to provide a pressure-type prefabricated pile structure to solve the problems of low single pile bearing capacity of conventional prefabricated pipe piles, easy cracking, poor durability and poor resistance to pressurized water.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A pressure-type prefabricated pile structure, characterized in that it comprises a pile structure, an end plate, a prestressed tendon rod, a locking device, and a pile tip; the pile structure is a cylindrical structure made of reinforced concrete material, and the center of the pile structure is a longitudinally long inner cavity; the end plates are metal steel plates, which are arranged at both ends of the pile structure, and the two end plates are arranged concentrically, and the outer contour of the end plate plane is similar to the outer contour of the cross-section of the pile structure, and one or more through holes are provided at the center of the end plate, and the through holes match the specifications and quantity of the prestressed tendon rod; the prestressed tendon rod is composed of a single or multiple high-strength threaded steel bars or high-strength steel strands, and is located in the inner cavity of the pile structure, according to the design It is required to apply prestressing force, and the two ends of the prestressed tendon rod are respectively connected to the end plates; the prestressed tendon locking devices are located at the two ends of the pile structure, which can fix the prestressed tendon rod and lock the prestressing force exerted on the prestressed tendon rod on the end plates; the pile tip is a conical structure made of rolled metal plates, which is welded to the bottom of the pile structure, and the space enclosed by the pile tip can cover the bottom of the pile structure and the exposed locking device and the exposed prestressed tendon rod; through the mutual cooperation of the above-mentioned components, a pressure-type prefabricated pile structure is formed in which the prestressed tendon rod is arranged inside and the prestress exerted on the prestressed tendon rod is locked at the two ends of the pile structure.

[0008] Furthermore, the end plate is divided into an upper end plate and a lower end plate, the upper end plate is located at the top of the pile structure, and the lower end plate is located at the bottom of the pile structure; the top end of the prestressed tendon rod extends out of the upper end plate, and the extension length is determined according to the design requirements and is less than the thickness of the raft slab of the main structure. When the length of the prestressed tendon rod extending out of the upper end plate is insufficient, a connector is used to extend it.

[0009] Furthermore, the prestressed tendon locking device is a high-strength nut, an extrusion anchor or a clip-type anchor; when it is a high-strength nut, the high-strength nut has an extended flange, the height of the extended flange is not less than the wall thickness of the high-strength nut, and the width of the extended flange is less than the center distance between adjacent prestressed tendon rods. The setting of the extended flange can reduce the local pressure of the high-strength nut on the end plate.

[0010] Furthermore, anchor plates and spiral reinforcements are provided on the prestressed tendon rod body extending out of the upper end plate, the prestressed tendon rod body extending out of the upper end plate and the anchor plates and spiral reinforcements are integrally buried in the main structure raft slab, and a flexible water stop ring is placed on the prestressed tendon rod body extending out of the upper end plate.

[0011] Furthermore, the upper end plate is concentrically arranged with the upper end face of the pile structure, the diameter of the upper end plate is not less than 4 cm smaller than the outer contour of the upper end face of the pile structure, and the area outside the contact position between the upper end plate and the upper end face of the pile structure forms an annular space, which can contact with the lower end face of the pile driver to provide a contact surface for the pile driver to press the pile, and the upper end plate can limit the lateral displacement of the pile driver and provide guidance for the pile driver.

[0012] Furthermore, a temporary pile cap is provided at the top of the pile structure, and the temporary pile cap is a hollow cylindrical structure formed by rolling a steel plate; the height of the temporary pile cap is greater than the length of the prestressed tendon rod extending out of the upper end plate, the inner diameter is greater than the outer contour enclosed by the locking device of the upper end plate, and the outer diameter is smaller than the outer contour of the upper end surface of the pile structure and smaller than the inner diameter of the pile driver; the temporary pile cap is temporarily welded and fixed to the upper end plate or the top of the pile structure; the temporary pile cap can completely surround the exposed prestressed tendon rod and the locking device of the upper end plate for isolation and protection; during the pile driving construction stage, the temporary pile cap can provide vertical guidance for the pile driver and limit the lateral displacement of the pile driver, and during the earth excavation stage in the pile top area, the temporary pile cap can isolate the contact between the prestressed tendon rod and the external cement soil and concrete.

[0013] Furthermore, a foamed isolation material is filled inside the temporary pile cap and / or an isolation sheath is placed outside the prestressed tendon rod body in the temporary pile cap, so as to facilitate removal of the pile cap and cleaning of the pile head.

[0014] Furthermore, all the prestressed tendon rods located in the inner cavity of the pile structure or the prestressed tendon rods except for a local length at the bottom end are coated with lubricant, and an isolation sleeve is provided outside the lubricant.

[0015] Furthermore, grouting holes and exhaust holes are provided on the upper end plate and the lower end plate, and a grouting pipe is tied to the prestressed tendon rod body. The upper end of the grouting pipe extends out of the outer side of the upper end plate, and the lower end extends into the space enclosed by the pile tip, and cementitious material is poured into the pile tip and the inner cavity of the pile structure through the grouting pipe; or grouting holes and exhaust holes are provided on the upper end plate and the side of the pile tip, and the cementitious material in the inner cavity of the pile structure and the pile tip is poured respectively through the two grouting ports; or grouting holes and exhaust holes are provided only on the upper end plate, and the cementitious material in the inner cavity of the pile structure is poured through the grouting port of the upper end plate; the cementitious material is cement slurry or cement mortar.

[0016] Furthermore, a flexible water stop ring is arranged at the contact position between the lower end plate and the end face of the pile structure to improve the waterproof airtightness of the lower end plate; epoxy resin glue is applied to the contact position between the lower end plate and the locking device and the contact position between the locking device and the prestressed tendon rod body to perform waterproof sealing, which can also avoid loosening of the locking device caused by vibration and reduce prestress loss caused by vibration of the prestress.

[0017] Furthermore, the pressure-type prefabricated pile structure can be used alone or in combination with mixing piles and cast-in-place piles to form a composite pile body structure. When it is a composite pile body structure, a limit block is set on the outside of the pile body structure to control the concentricity of the prefabricated piles and the peripheral mixing piles and cast-in-place piles.

[0018] Compared with the prior art, the advantages of the pressure-type prefabricated pile structure described in the utility model are: it includes a pile structure, an end plate, a prestressed tendon rod, a locking device, and a pile tip; the pile structure is a cylindrical structure made of reinforced concrete material, and the center of the pile structure is a longitudinal inner cavity; the end plates are metal steel plates, which are arranged at both ends of the pile structure, and the two end plates are concentrically arranged, and the outer contour of the end plate plane is similar to the outer contour of the cross-section of the pile structure. One or more through holes are provided at the center of the end plate, and the through holes match the specifications and quantity of the prestressed tendon rod; the prestressed tendon rod is composed of a single or multiple high-strength threaded steel bars or high-strength steel strands, which are located in the inner cavity of the pile structure, and the prestressing force is applied according to the design requirements The two ends of the prestressed tendon rod are respectively connected to the end plates; the prestressed tendon locking devices are located at the two ends of the pile structure, which can fix the prestressed tendon rod and lock the prestressing force exerted on the prestressed tendon rod on the end plates; the pile tip is a conical structure formed by rolling a metal plate and welded to the bottom of the pile structure, and the space enclosed by the pile tip can cover the bottom of the pile structure and the exposed locking device and the exposed prestressed tendon rod; through the mutual cooperation of the above components, a pressure-type prefabricated pile structure is formed in which a prestressed tendon rod is arranged inside and the prestress exerted on the prestressed tendon rod is locked at both ends of the pile structure, thereby solving the problems of low bearing capacity, easy cracking, poor durability and inability to withstand pressurized water of conventional prefabricated pipe piles. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a front view of a pressure-type prefabricated pile structure according to an embodiment of the utility model;

[0020] Figure 2 This is a detailed diagram of the connection between the pile top and the raft slab of a pressure-type prefabricated pile structure according to an embodiment of the utility model;

[0021] Figure 3 This is a detailed diagram of the pile top and pile bottom of a pressure-type prefabricated pile structure according to an embodiment of the utility model (the lower end plate has a slurry inlet hole and an exhaust hole);

[0022] Figure 4 This is a detailed diagram of the pile top and pile bottom of a pressure-type prefabricated pile structure according to an embodiment of the utility model (the lower end plate has no grout inlet hole and exhaust hole);

[0023] Figure 5 A detailed view of the top of a pressure-type prefabricated pile structure (with a temporary pile cap) according to an embodiment of the utility model;

[0024] Figure 6 This is a top view of an upper end plate of a pressure-type prefabricated pile structure according to an embodiment of the utility model (without a temporary pile cap);

[0025] Figure 7 This is a top view of an upper end plate of a pressure-type prefabricated pile structure (with a temporary pile cap) according to an embodiment of the utility model.

[0026] Reference numerals:

[0027] 1: Pile structure; 1-1: Inner cavity.

[0028] 2: end plate; 2-1: upper end plate; 2-2: lower end plate; 2-3: through hole; 2-4: annular space; 2-5: water stop ring; 2-6: slurry inlet hole; 2-7: exhaust hole.

[0029] 3: Prestressed tendon rod; 3-1: Isolation sleeve; 3-2: Grouting pipe.

[0030] 4: Locking device; 4-1: High-strength nut; 4-2: Extended flange.

[0031] 5: Pile tip.

[0032] 6: Anchor plate.

[0033] 7: Spiral rib.

[0034] 8: Raft.

[0035] 9: Temporary pile cap.

[0036] 10: Foam insulation material. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with specific embodiments, but the present invention is not limited to these specific embodiments. Those skilled in the art should recognize that the present invention covers all possible alternatives, improvements and equivalents within the scope of the claims.

[0038] like Figure 1-7As shown, a pressure-type prefabricated pile structure is characterized in that it includes a pile structure (1), an end plate (2), a prestressed tendon rod (3), a locking device (4), and a pile tip (5); the pile structure (1) is a cylindrical structure made of reinforced concrete material, and the center of the pile structure (1) is a longitudinal inner cavity (1-1); the end plate (2) is a metal steel plate, which is arranged at both ends of the pile structure (1), and the two end plates (2) are arranged concentrically, and the plane outer contour of the end plate (2) is similar to the cross-sectional outer contour of the pile structure (1), and one or more through holes (2-3) are provided at the center of the end plate (2), and the through holes (2-3) match the specifications and quantity of the prestressed tendon rod (3); the prestressed tendon rod (3) is composed of a single or multiple high-strength threaded steel or high-strength steel strands, and is located in the inner cavity (1) of the pile structure (1). 1-1), the prestressing force is applied according to the design requirements, and the two ends of the prestressed tendon rod body (3) are respectively connected to the end plates (2); the prestressed tendon locking devices (4) are located at the two ends of the pile structure (1), and can fix the prestressed tendon rod body (3) and lock the prestressed force applied to the prestressed tendon rod body (3) on the end plates (2); the pile tip (5) is a conical structure formed by rolling a metal plate and welded to the bottom of the pile structure (1), and the space enclosed by the pile tip (5) can cover the bottom of the pile structure (1) and the exposed locking device (4) and the exposed prestressed tendon rod body (3); through the mutual cooperation of the above-mentioned components, a pressure-type prefabricated pile structure is formed, in which the prestressed tendon rod body (3) is arranged inside and the prestress applied to the prestressed tendon rod body (3) is locked at the two ends of the pile structure (1).

[0039] As an optional embodiment, the end plate (2) is divided into an upper end plate (2-1) and a lower end plate (2-2), the upper end plate (2-1) is located at the top of the pile structure (1), and the lower end plate (2-2) is located at the bottom of the pile structure (1); the top end of the prestressed tendon rod (3) extends out of the upper end plate (2-1), and the extension length is determined according to design requirements and is less than the thickness of the main structure raft slab. When the length of the prestressed tendon rod (3) extending out of the upper end plate (2-1) is insufficient, a connector is used to extend it.

[0040] As an optional embodiment, the prestressed tendon locking device (4) is a high-strength nut (4-1), an extrusion anchor or a clip-type anchor; when it is a high-strength nut (4-1), the high-strength nut (4-1) has an extended flange (4-2), the height of the extended flange (4-2) is not less than the wall thickness of the high-strength nut (4-1), and the width of the extended flange (4-2) is less than the center distance between adjacent prestressed tendon rods (3). The setting of the extended flange (4-2) can reduce the local pressure of the high-strength nut (4-1) on the end plate (2).

[0041] As an optional embodiment, an anchor plate (6) and a spiral rib (7) are provided on the prestressed tendon rod body (3) extending out of the upper end plate (2-1); the prestressed tendon rod body (3) extending out of the upper end plate (2-1) and the anchor plate (6) and the spiral rib (7) are integrally embedded in the main structure raft slab (8); when the waterproof requirement is high, a flexible water stop ring (2-5) is placed on the prestressed tendon rod body extending out of the upper end plate (2-1).

[0042] As an optional embodiment, the upper end plate (2-1) is concentrically arranged with the upper end surface of the pile structure (1), the diameter of the upper end plate (2-1) is not less than 4 cm smaller than the outer contour of the upper end surface of the pile structure (1), and the area outside the contact position between the upper end plate (2-1) and the upper end surface of the pile structure (1) forms an annular space (2-4), and the annular space (2-4) can contact with the lower end surface of the pile driver to provide a contact surface for the pile driver to press the pile, and the upper end plate (2-1) can limit the lateral displacement of the pile driver and provide guidance for the pile driver.

[0043] As an optional embodiment, a temporary pile cap (9) is provided at the top of the pile structure (1). The temporary pile cap structure (9) is an auxiliary component in the process of pile driving and pile delivery construction. It is removed before the pile top is connected to the raft slab. After removal, spiral stirrups and anchor plates are placed on the pile top. The temporary pile cap (9) is a hollow cylindrical structure made of rolled steel plates. The height of the temporary pile cap (9) is greater than the length of the prestressed tendon rod (3) extending out of the upper end plate (2-1), the inner diameter is greater than the outer contour enclosed by the locking device (4) of the upper end plate (2-1), and the outer diameter is smaller than the upper end plate (2-1). The temporary pile cap (9) is temporarily welded and fixed to the upper end plate (2-1) or the top of the pile structure (1); the temporary pile cap (9) can completely surround the exposed prestressed tendon rod body (3) and the locking device (4) of the upper end plate (2-1) for isolation and protection; during the pile driving construction stage, the temporary pile cap (9) can provide vertical guidance for the pile driver and limit the lateral displacement of the pile driver; during the excavation stage of the pile top area, the temporary pile cap (9) can isolate the prestressed tendon rod body (3) from contact with external cement soil and concrete.

[0044] As an optional embodiment, a foamed insulating material (10) is filled inside the temporary pile cap (9) and / or an insulating sheath is placed outside the prestressed tendon rod (3) inside the temporary pile cap (9), so as to facilitate the removal of the pile cap and the cleaning of the pile head.

[0045] As an optional embodiment, all prestressed tendon rods (3) located in the inner cavity (1-1) of the pile structure (1) or the prestressed tendon rods (3) except for a local length at the bottom are coated with lubricant, and an isolation sleeve (3-1) is provided outside the lubricant.

[0046] As an optional embodiment, Figure 3As shown, a grouting hole (2-6) and an exhaust hole (2-7) are provided on the upper end plate (2-1) and the lower end plate (2-2), and a grouting pipe (3-2) is tied to the prestressed tendon rod (3). The upper end of the grouting pipe (3-2) extends out of the outer side of the upper end plate (2-1), and the lower end extends into the space enclosed by the pile tip (5). The cementitious material is poured into the pile tip (5) and the inner cavity (1-1) of the pile structure (1) through the grouting pipe (3-2). During the pouring process, the space inside the pile tip (5) is filled first, and the grouting returns from the exhaust hole (2-7) of the lower end plate (2-2). As the grouting pipe (3-2) continues to be poured, the inner cavity (1-1) of the pile structure (1) is filled, and the grouting returns from the exhaust hole (2-7) of the upper end plate (2-1); or as shown in FIG. Figure 4 As shown, the upper end plate (2-1) and the pile tip (5) are provided with grout inlet holes (2-6) and exhaust holes (2-7), while the lower end plate (2-2) has no grout inlet holes (2-6) and exhaust holes (2-7). The lower end plate (2-2) isolates the inner cavity (1-1) of the pile structure (1) from the pile tip (5), and the cementitious material in the inner cavity (1-1) of the pile structure (1) and the pile tip (5) is poured through the grout inlet holes of the upper end plate and the pile tip, respectively. Note: or only the upper end plate (2-1) is provided with a grout inlet hole (2-6) and an exhaust hole (2-7), and the cementitious material is poured into the inner cavity (1-1) of the pile structure (1) through the grout inlet of the upper end plate (2-1). At this time, no cementitious material is filled in the pile tip (5), and the anti-corrosion treatment can be carried out by applying an anti-corrosion material to the inner end plate (2) of the pile tip (5), the locking device (4), and the prestressed tendon rod (3); the cementitious material is cement slurry or cement mortar.

[0047] As an optional embodiment, a flexible water stop ring (2-5) is provided at the contact position between the lower end plate (2-2) and the end surface of the pile structure (1) to improve the waterproof tightness of the lower end plate (2-2). Epoxy resin glue is applied at the contact position between the lower end plate (2-2) and the locking device (4) and the contact position between the locking device (4) and the prestressed tendon rod (3) to achieve waterproof sealing. When the prestressed tendon rod (3) is a precision-rolled threaded steel bar, the rib angle of the threaded steel bar is large, and the spacing between adjacent ribs is also large. The vibration during transportation may cause the nuts to loosen and cause the loss of prestress. After applying epoxy resin, the locking device (4) can be fixed to the steel bar, which can avoid the loosening of the locking device (4) caused by vibration and reduce the loss of prestress caused by vibration. When long-distance transportation is required, the wire can be firstly wound at the position where the locking device (4) is exposed outside the threaded steel bar, and then the epoxy resin can be applied.

[0048] As an optional embodiment, the pressure-type prefabricated pile structure can be used alone or in combination with a mixing pile or a cast-in-place pile to form a composite pile body structure (1). When it is a composite pile body structure (1), a limit block is provided on the outside of the pile body structure (1) to control the concentricity of the prefabricated pile and the peripheral mixing pile or cast-in-place pile.

Claims

1. A pressure type prefabricated pile structure, characterized in that: It includes a pile structure, an end plate, a prestressed tendon rod, a locking device, and a pile tip; the pile structure is a cylindrical structure made of reinforced concrete material, and the center of the pile structure is a longitudinal inner cavity; the end plates are metal steel plates, which are arranged at both ends of the pile structure, and the two end plates are arranged concentrically, and the outer contour of the end plate plane is similar to the outer contour of the cross-section of the pile structure. One or more through holes are arranged at the center of the end plate, and the through holes match the specifications and quantity of the prestressed tendon rod; the prestressed tendon rod is composed of a single or multiple high-strength threaded steel bars or high-strength steel strands, which are located in the inner cavity of the pile structure and pre-tensioned according to design requirements. The prestressed tendon rod is applied, and both ends of the prestressed tendon rod are connected to the end plates respectively; the prestressed tendon locking devices are located at both ends of the pile structure, which can fix the prestressed tendon rod and lock the prestressing force exerted on the prestressed tendon rod on the end plates; the pile tip is a conical structure formed by rolling a metal plate, which is welded to the bottom of the pile structure, and the space enclosed by the pile tip can cover the bottom of the pile structure and the exposed locking device and the exposed prestressed tendon rod; through the mutual cooperation of the above-mentioned components, a pressure-type prefabricated pile structure is formed in which a prestressed tendon rod is arranged inside and the prestress exerted on the prestressed tendon rod is locked at both ends of the pile structure.

2. A pressure-type prefabricated pile structure according to claim 1, characterized in that: The end plate is divided into an upper end plate and a lower end plate. The upper end plate is located at the top of the pile structure, and the lower end plate is located at the bottom of the pile structure. The top end of the prestressed tendon rod extends out of the upper end plate, and the extension length is determined according to the design requirements and is less than the thickness of the raft slab of the main structure. When the length of the prestressed tendon rod extending out of the upper end plate is insufficient, a connector is used to extend it.

3. A pressure-type prefabricated pile structure according to claim 1, characterized in that: The prestressed tendon locking device is a high-strength nut, an extrusion anchor or a clip-type anchor; when it is a high-strength nut, the high-strength nut has an extended flange, the height of the extended flange is not less than the wall thickness of the high-strength nut, and the width of the extended flange is less than the center distance between adjacent prestressed tendon rods. The setting of the extended flange can reduce the local pressure of the high-strength nut on the end plate.

4. A pressure-type prefabricated pile structure according to claim 2, characterized in that: Anchor plates and spiral tendons are arranged on the prestressed tendon rod body extending out of the upper end plate, and the prestressed tendon rod body extending out of the upper end plate, the anchor plates and spiral tendons are integrally buried in the main structure raft slab.

5. A pressure-type prefabricated pile structure according to claim 2, characterized in that: The upper end plate is arranged concentrically with the upper end face of the pile structure, and the diameter of the upper end plate is not less than 4 cm smaller than the outer contour of the upper end face of the pile structure. The area outside the contact position between the upper end plate and the upper end face of the pile structure forms an annular space, which can contact the lower end face of the pile driver to provide a contact surface for the pile driver to press the pile. The upper end plate can limit the lateral displacement of the pile driver and provide guidance for the pile driver.

6. A pressure-type prefabricated pile structure according to claim 2, characterized in that: A temporary pile cap is arranged at the top of the pile structure, and the temporary pile cap is a hollow cylindrical structure formed by rolling a steel plate; the height of the temporary pile cap is greater than the length of the prestressed tendon rod body extending out of the upper end plate, the inner diameter is greater than the outer contour surrounded by the locking device of the upper end plate, and the outer diameter is smaller than the outer contour of the upper end surface of the pile structure and smaller than the inner diameter of the pile driver; the temporary pile cap is temporarily welded and fixed to the upper end plate or the top of the pile structure; the temporary pile cap can completely surround the exposed prestressed tendon rod body and the locking device of the upper end plate for isolation and protection; during the pile driving construction stage, the temporary pile cap can provide vertical guidance for the pile driver and limit the lateral displacement of the pile driver, and during the earth excavation stage in the pile top area, the temporary pile cap can isolate the prestressed tendon rod body from the contact with the external cement soil and concrete; the interior of the temporary pile cap is filled with foamed isolation material and / or an isolation sheath is placed on the outer side of the prestressed tendon rod body in the temporary pile cap, so as to facilitate the removal of the pile cap and the cleaning of the pile head.

7. A pressure-type prefabricated pile structure according to claim 2, characterized in that: Grouting holes and exhaust holes are provided on the upper end plate and the lower end plate, and a grouting pipe is tied to the prestressed tendon rod. The upper end of the grouting pipe extends out of the outer side of the upper end plate, and the lower end extends into the space enclosed by the pile tip, and cementitious material is poured into the pile tip and the inner cavity of the pile structure through the grouting pipe; or grouting holes and exhaust holes are provided on the upper end plate and the side of the pile tip, and the cementitious material in the inner cavity of the pile structure and the pile tip is poured respectively through the two grouting ports; or grouting holes and exhaust holes are provided only on the upper end plate, and the cementitious material is poured into the inner cavity of the pile structure through the grouting port of the upper end plate; the cementitious material is cement slurry or cement mortar.

8. A pressure-type prefabricated pile structure according to claim 7, characterized in that: All prestressed tendon rods located in the inner cavity of the pile structure or the prestressed tendon rods except for a local length at the bottom are coated with lubricant, and an isolation sleeve is arranged outside the lubricant.

9. A pressure-type prefabricated pile structure according to claim 2, characterized in that: A flexible water stop ring is arranged at the contact position between the lower end plate and the end face of the pile structure to improve the waterproof tightness of the lower end plate; epoxy resin glue is applied to the contact position between the lower end plate and the locking device and the contact position between the locking device and the prestressed tendon rod body to perform waterproof sealing, which can also avoid loosening of the locking device caused by vibration and reduce prestress loss caused by vibration of the prestress.

10. A pressure-type prefabricated pile structure according to any one of claims 1 to 9, characterized in that: The pressure-type prefabricated pile structure can be used alone or in combination with mixing piles and cast-in-place piles to form a composite pile structure. When it is a composite pile structure, a limit block is set on the outside of the pile structure to control the concentricity of the prefabricated pile and the peripheral mixing piles and cast-in-place piles.

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