A pile body connecting structure for a combined prestressed pile

Abstract

This utility model provides a pile connection structure for composite prestressed piles, including an upper end plate structure, a lower end plate structure, a male tenon structure, a female tenon structure, an elastic positioning mechanism, a locking mechanism, a sealing structure, and a fixing structure. The male tenon structure is disposed on the end face of the upper end plate structure facing the mating side, and the female tenon structure is disposed on the opposite end face of the lower end plate structure. The male and female tenon structures are axially inserted along the pile axis to achieve coaxial positioning. The elastic positioning mechanism is disposed between the male and female tenon structures and provides pre-tightening force in the insertion direction, so that the mating surfaces of the male and female tenon structures self-center and fit together under force. The pile connection structure for composite prestressed piles described in this utility model solves the problem that insufficient control of end plate processing and assembly precision in related technologies leads to stress concentration and structural weakening at the pile joint connection during stress.

Description

Technical Field

[0001] This utility model belongs to the field of pipe pile technology, and in particular relates to a pile connection structure for composite prestressed piles. Background Technology

[0002] In pile foundation construction, composite prestressed piles have gradually become a commonly used pile type in deep foundation and high-load projects due to their ability to achieve ultra-long pile construction through segmented prefabrication and on-site splicing. These piles are typically prestressed in a factory using a pre-tensioning process to apply prestress to high-strength steel bars or steel strands and fabricate standard segments. This segmented design allows for flexible adaptation to different geological conditions and construction environments, offering significant advantages, especially in situations where transportation is limited or deep pile foundations are required. Their overall structure boasts advantages such as good crack resistance, high bearing capacity, stable quality, and convenient construction, making them an important technical approach for improving the efficiency and quality control of pile foundation construction in current engineering projects.

[0003] In existing technologies, the segmental connection of composite prestressed piles relies on the reliable transfer of force and stiffness through end plate mating. Insufficient end plate machining precision can lead to gaps or eccentricity during pile segment splicing, resulting in stress concentration at the connection point. This makes the area a weak point, affecting the overall load-bearing performance and pile foundation safety. Due to insufficient control over the machining and assembly precision of end plates in related technologies, stress concentration and structural weakening are prone to occur at the pile segment connection points during stress loading. Summary of the Invention

[0004] In view of this, the present invention aims to at least partially solve one of the related technical problems.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0006] A pile connection structure for composite prestressed piles includes an upper end plate structure, a lower end plate structure, a male tenon structure, a female tenon structure, an elastic positioning mechanism, a locking mechanism, a sealing structure, and a fixing structure.

[0007] The male tenon structure is disposed on the end face of the upper end plate structure facing the docking side, and the female tenon structure is disposed on the opposite end face of the lower end plate structure. The male tenon structure and the female tenon structure are axially inserted on the pile axis to achieve coaxial positioning.

[0008] The elastic positioning mechanism is disposed between the male tenon structure and the upper end plate structure and provides pre-tightening force in the insertion direction, so that the mating surfaces of the male tenon structure and the female tenon structure self-center and fit together under force;

[0009] The locking mechanism is distributed along the circumferential direction and spans the junction of the male and female falcons to limit their relative radial / tangential displacement and form a mechanical lock.

[0010] The sealing structure is arranged at the end of the male tenon structure and cooperates with the female tenon structure to guide and seal the insertion part;

[0011] The fixing structure includes a locking assembly that clamps and fixes the upper end plate structure and the lower end plate structure along the axial direction of the pile.

[0012] Furthermore, the upper end plate structure includes an end plate body and a thickened pad. The thickened pad is disposed on the side of the end plate body facing away from the docking side and is used for anchoring connection with the steel cage and / or prestressing tendons of the pile. The lower end plate structure has the same structural form as the upper end plate structure.

[0013] Furthermore, the male falcon structure includes an annular positioning protrusion, the outer peripheral surface of which is a conical positioning surface.

[0014] Furthermore, the serpentine structure includes an annular insert sleeve, the inner wall of which is a conical structure that mates with the outer conical positioning surface of the annular positioning protrusion, and the bottom of the conical structure is provided with an annular end face that fits against the bottom end face of the annular positioning protrusion.

[0015] Furthermore, the elastic positioning mechanism includes a compression spring and a positioning sleeve. The compression spring is sleeved on the outside of the annular positioning protrusion, with one end connected to the end plate body of the upper end plate structure and the other end connected to the positioning sleeve. The end plate body of the lower end plate structure is provided with an annular groove that can be inserted into the positioning sleeve.

[0016] The diameter of the annular groove is larger than the outer diameter of the positioning sleeve, and the bottom of the groove is provided with a limiting shoulder to provide axial limiting and radial guidance for the positioning sleeve during assembly.

[0017] Furthermore, the locking mechanism includes a plurality of wedges evenly arranged along the circumference, the wedges penetrating the joint between the male and female falcons;

[0018] The annular positioning protrusion is provided with a first through hole that mates with the wedge, and the annular insertion sleeve is provided with a second through hole that mates with the wedge, so that the wedge forms a radial self-locking structure after assembly.

[0019] Furthermore, the sealing structure includes a guide sleeve, multiple sealing rings, and a sealing gasket. The guide sleeve is fixed to the bottom end face of the annular positioning protrusion and is used to insert into the bottom area of ​​the annular insertion sleeve. The multiple sealing rings are arranged axially on the outer wall of the guide sleeve. The sealing gasket is disposed on the bottom end face of the annular positioning protrusion and abuts against the annular end face to form an end face seal.

[0020] Furthermore, the fixing structure includes a plurality of locking components evenly arranged along the circumference, each of the locking components including a locking bolt penetrating the upper end plate structure and the lower end plate structure and a nut that cooperates with it.

[0021] Furthermore, the wedge is a radially inserted inclined wedge structure, whose wedge-shaped inclined surface matches the mating surface of the first through hole and / or the second through hole to enhance the radial clamping force when subjected to axial pressure.

[0022] Furthermore, it also includes a shoulder structure, which includes an annular shoulder and a metal gasket. The annular shoulder is disposed on the end face of the mating side of the lower baffle structure, and the metal gasket is disposed on the end face of the mating side of the upper baffle structure. The annular shoulder is used to abut against the metal gasket.

[0023] Compared with existing technologies, the pile connection structure for composite prestressed piles described in this utility model has the following advantages:

[0024] 1. During assembly, the conical positioning surface achieves rapid self-centering through the transition from line contact to surface contact, significantly reducing the stringent requirements for on-site measurement and hoisting accuracy. After locking, it forms a large-area metal-metal bonding interface to effectively reduce the peak contact stress. The radial wedge clamping of the wedge block generates a self-reinforcing effect under axial external load, thereby suppressing shear slip caused by slight eccentricity or construction tolerance and improving circumferential shear and torsional stiffness. The end-face bearing band formed by the annular shoulder and metal gasket not only provides a controllable termination position for the conical surface bonding but also bears part of the axial pressure under large load conditions to avoid excessive stress concentration on a single conical surface. As a result, the stress distribution in the connection area is more uniform, local weak points are significantly weakened, and the overall load-bearing capacity, stiffness, and ductility are optimized in a coordinated manner, thereby improving the long-term safety reserve of the pile foundation under complex loads.

[0025] 2. The guide sleeve provides hard guidance in the early stages of assembly and prevents the sealing ring from being sheared and scratched during insertion. The multiple axially arranged sealing rings form a stepped barrier, providing higher redundancy and fault tolerance for media such as groundwater and mud. The end face sealing gasket achieves the final end face pressure seal under the compression of the annular shoulder-metal gasket, giving the connection area both guiding and sealing functions. The wedge block and conical surface and other key mating surfaces are treated with anti-seize and corrosion-resistant materials, allowing for easy unlocking and disassembly after long-term service. This facilitates partial replacement and reassembly when necessary, and makes maintenance convenient. Attached Figure Description

[0026] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0027] Figure 1 This is a schematic diagram of a pile connection structure for a combined prestressed pile according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the male falcon structure described in an embodiment of the present utility model;

[0029] Figure 3 This is a schematic diagram of the sealing structure described in an embodiment of the present utility model;

[0030] Figure 4 This is a schematic diagram of the scimitar structure described in an embodiment of the present utility model;

[0031] Figure 5 This is a schematic diagram of the thickened pad described in an embodiment of the present invention.

[0032] Explanation of reference numerals in the attached figures:

[0033] 100. Upper end plate structure; 110. Locking bolt; 120. Nut; 130. Lower end plate structure; 200. Elastic positioning mechanism; 210. Compression spring; 220. Positioning sleeve; 230. Annular groove; 300. Fence structure; 310. Annular insertion sleeve; 320. Annular end face; 330. Second through hole; 400. Shoulder structure; 410. Metal gasket; 420. Annular shoulder; 510. Annular positioning protrusion; 511. Annular sealing gasket; 520. Guide sleeve; 521. Sealing ring; 530. First through hole. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0035] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0036] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0037] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] Referring to the application scenarios described in the background technology, in order to solve the engineering pain points of the difficulty in ensuring the coaxiality of composite prestressed pile segments during on-site splicing, and the stress concentration caused by gaps and eccentricity in the connection area, which weakens the overall load-bearing capacity and durability, this embodiment proposes a pile connection structure for composite prestressed piles. The structure is organically composed of an upper end plate structure 100, a lower end plate structure 130, a male tenon structure, a female tenon structure 300, an elastic positioning mechanism 200, a locking mechanism, a sealing structure, and a fixing structure unit.

[0039] The upper end plate structure 100 includes an end plate body and a thickened pad plate for reliable anchoring with the pile reinforcement cage and / or prestressed tendons (the thickened pad plate is arranged on the side of the end plate body facing away from the butt joint, so that it can be pre-stressed in the factory and then anchored by welding of steel bars or grouting of sleeves to form an integral stress section). The lower end plate structure 130 is the same as the upper end plate structure 100 in structure and function so as to achieve interchangeable manufacturing and assembly.

[0040] The male tenon structure is located on the end face of the upper end plate structure 100 facing the mating side and specifically includes an annular positioning protrusion 510. The outer peripheral surface of the annular positioning protrusion 510 is machined into a conical positioning surface (preferably a linear conical surface with a half-angle of 5° to 8° and a surface roughness of Ra1.6 or better to obtain repeatable metal-to-metal bonding). The corresponding female tenon structure 300 is located on the opposite end face of the lower end plate structure 130 and specifically includes an annular insertion sleeve 310. The inner wall of the annular insertion sleeve 310 is a conical surface structure that mates with the outer peripheral conical surface of the annular positioning protrusion 510, and its bottom is provided with an annular end face 320 for mating with the bottom end face of the annular positioning protrusion 510, thereby achieving axial insertion guidance and self-alignment on the segment axis. To ensure a secure fit and provide continuous axial preload during insertion and to suppress minor backlash and vibration-induced loosening, an elastic positioning mechanism 200 is provided between the male tenon structure and the upper end plate structure 100. This mechanism includes a compression spring 210 sleeved on the outside of the annular positioning protrusion 510 and a positioning sleeve 220 coaxially connected thereto. One end of the compression spring 210 is connected to the end plate body of the upper end plate structure 100, and the other end is connected to the positioning sleeve 220. The end plate body of the lower end plate structure 130 is correspondingly provided with an annular groove 230 that can be inserted into the positioning sleeve 220. The groove opening diameter of the annular groove 230 is slightly larger than the outer diameter of the positioning sleeve 220, and the bottom of the groove is provided with an annular limiting shoulder to provide clear axial stop and radial guidance during the assembly stage.

[0041] The locking mechanism forms a mechanical circumferential self-locking at the joint of the male and female tenons and restricts their relative radial / tangential displacement. The locking mechanism consists of multiple wedges evenly distributed along the circumference. Each wedge passes through the joint and is respectively matched with the first through hole 530 on the annular positioning protrusion 510 and the second through hole 330 on the annular insertion sleeve 310. The wedges preferably adopt a radially inserted oblique wedge structure and make their wedge-shaped oblique surfaces engage with the mating surfaces of the first through hole 530 and / or the second through hole 330 in an oblique meshing relationship so as to generate amplified radial clamping force under axial pressure and operational vibration to form a reliable self-locking state.

[0042] The sealing structure is designed to combine assembly guidance, media barrier, and end-face sealing. The sealing structure includes a guide sleeve 520 fixed to the bottom end face of the annular positioning protrusion 510, multiple sealing rings 521 arranged axially along the outer wall of the guide sleeve 520, and a sealing gasket arranged on the bottom end face of the annular positioning protrusion 510 and abutting against the annular end face 320. The guide sleeve 520 undertakes the hard guiding function and the radial support function of the sealing rings 521 in the initial insertion stage. The sealing rings 521 can be selected from oil-resistant and heat-resistant elastomers (such as FKM or NBR) according to the characteristics of the medium and adopt ≥ two-stage step-by-step sealing to reduce the risk of leakage. The sealing gasket should preferably be a metal-coated graphite or polytetrafluoroethylene composite gasket to form an end-face seal.

[0043] The fixing structure is designed to clamp the upper and lower end plates together in the axial direction and transfer external loads. The fixing structure consists of multiple locking components evenly arranged along the circumference. Each locking component includes a locking bolt 110 that passes through the upper end plate structure 100 and the lower end plate structure 130 and a nut 120 that mates with it. The locking components are preferably tightened symmetrically and crosswise, and the threads are coated with anti-seize agent to ensure long-term maintainability. In addition, to further limit the mating and pressing position and improve the stress distribution on the end face, a shoulder structure 400 is also provided. The shoulder structure 400 includes an annular shoulder 420 and a metal washer 410. The annular shoulder 420 is located on the mating side end face of the lower end plate structure 130, and the metal washer 410 is located on the mating side end face of the upper end plate structure 100. After the locking components are tightened, the annular shoulder 420 forms a surface contact support for the metal washer 410 and provides a controllable termination position and an additional end face bearing ring for the conical surface fit.

[0044] In terms of manufacturing and tolerance control, the conical surface fit between the annular positioning protrusion 510 and the annular insertion sleeve 310 preferably adopts H7 / h7 grade or equivalent control requirements and ensures that the roundness and coaxiality are not greater than 0.10mm, so as to reduce local hard spots caused by manufacturing deviations. The chamfer of the groove opening of the annular groove 230 matches the chamfer of the end edge of the guide sleeve 520 to avoid scratching the sealing ring 521 during assembly. The preload of the compression spring 210 under the maximum assembly compression displacement should account for 10% to 20% of the design axial clamping force of the connection area to establish a basic fit before locking. The surface of the wedge block can be phosphated or nickel-plated to improve the anti-galling performance and maintain the stable friction coefficient of the wedge surface during secondary disassembly and assembly. The locking bolt 110 can be an 8.8 grade or 10.9 grade high-strength bolt and paired with a lock nut 120 or a mechanical locking plate to adapt to vibration conditions.

[0045] How this example works

[0046] Step 1: At the factory or on-site, bring the upper and lower pile sections close together and initially align them, ensuring that the annular positioning protrusion 510 of the male tenon structure is coaxially aligned with the annular insertion sleeve 310 of the female tenon structure. Then, slowly advance the guide sleeve 520 along the pile axis, allowing it to enter the bottom area of ​​the annular insertion sleeve 310 first, achieving flexible guidance under the elastic support of the sealing ring 521. As the advancement stroke increases, the compression spring 210 is gradually compressed, driving the positioning sleeve 220 to press into the annular groove 230 and generating continuous axial preload until the annular positioning protrusion 510... The bottom end face of 0 is in contact with the annular end face 320, and the metal gasket 410 of the upper end plate structure 100 is in contact with the annular shoulder 420 of the lower end plate structure 130 to form an end face pressure seal. At this time, the wedge is radially inserted through the first through hole 530 and the second through hole 330 along the circumference and is driven or pressed into place in a symmetrical manner. Finally, the locking bolt 110 is passed through the upper and lower end plates and the nut 120 is tightened symmetrically to reach the specified torque. Thus, a reliable coaxial locking and sealing system is established under the combined action of conical surface contact, wedge self-locking, multi-stage sealing of sealing ring and end face pressure seal.

[0047] Step 2: When the pile is put into use and bears vertical pressure, horizontal force and bending moment, the external load is continuously transmitted through the path of upper pile concrete - thickened pad plate - end plate body - annular positioning protrusion conical surface - annular insertion sleeve - lower end plate body - thickened pad plate - lower pile. The self-centering geometry of the conical surface and the radial clamping effect of the wedge block will evenly disperse the additional bending moment caused by slight eccentricity within the circumference. The locking component provides stable clamping force in the axial direction and works with the end face bearing band of the annular shoulder - metal gasket to restrict the interface from opening. The sealing ring 521 and the sealing gasket remain sealed under the action of operating temperature and groundwater pressure. If unlocking maintenance is required, the locking component is unloaded symmetrically in the opposite order, the wedge block is pulled out, and the conical surface is released under the rebound action of the compression spring 210 to achieve safe disassembly.

[0048] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A pile body connecting structure for a combined prestressed pile, characterized by: It includes an upper end plate structure (100), a lower end plate structure (130), a male tenon structure, a female tenon structure (300), an elastic positioning mechanism (200), a locking mechanism, a sealing structure, and a fixing structure; The male tenon structure is disposed on the end face of the upper end plate structure (100) facing the docking side, and the female tenon structure (300) is disposed on the opposite end face of the lower end plate structure (130). The male tenon structure and the female tenon structure (300) are axially inserted on the pile axis to achieve coaxial positioning. The elastic positioning mechanism (200) is disposed between the male tenon structure and the upper end plate structure (100) and provides pre-tightening force in the insertion direction, so that the mating surfaces of the male tenon structure and the female tenon structure (300) self-center and fit together under force; The locking mechanism is distributed along the circumferential direction and spans the junction of the male falcon structure and the female falcon structure (300) to limit the relative radial / tangential displacement of the two and form a mechanical lock. The sealing structure is arranged at the end of the male tenon structure and cooperates with the female tenon structure (300) to guide and seal the insertion part; The fixing structure includes a locking assembly that clamps and fixes the upper end plate structure (100) and the lower end plate structure (130) along the axial direction of the pile body.

2. A pile connecting structure according to claim 1, characterized in that: The upper end plate structure (100) includes an end plate body and a thickened pad. The thickened pad is disposed on the side of the end plate body facing away from the docking side and is used for anchoring connection with the steel cage and / or prestressed tendons of the pile. The lower end plate structure (130) has the same structural form as the upper end plate structure (100).

3. The pile connection structure according to claim 1, characterized in that: The yang falcon structure includes an annular positioning protrusion (510), and the outer peripheral surface of the annular positioning protrusion (510) is a conical positioning surface.

4. The pile connection structure according to claim 3, characterized in that: The scimitar structure (300) includes an annular insert sleeve (310), the inner wall of which is a conical structure that matches the conical positioning surface of the annular positioning protrusion (510) on its outer periphery, and the bottom of the conical structure is provided with an annular end face (320) that fits against the bottom end face of the annular positioning protrusion (510).

5. A pile connecting structure according to claim 4, characterized in that: The elastic positioning mechanism (200) includes a compression spring (210) and a positioning sleeve (220). The compression spring (210) is sleeved on the outside of the annular positioning protrusion (510), with one end connected to the end plate body of the upper end plate structure (100) and the other end connected to the positioning sleeve (220). The end plate body of the lower end plate structure (130) is provided with an annular groove (230) that can be inserted into the positioning sleeve (220). The diameter of the annular groove (230) is larger than the outer diameter of the positioning sleeve (220), and the bottom of the groove is provided with a limiting shoulder to provide axial limiting and radial guidance for the positioning sleeve (220) during assembly.

6. A pile connecting structure according to claim 5, characterized in that: The locking mechanism includes a plurality of wedges evenly arranged along the circumference, the wedges penetrating the joint between the male and female falcon structures (300); The annular positioning protrusion (510) is provided with a first through hole (530) that mates with the wedge, and the annular insertion sleeve (310) is provided with a second through hole (330) that mates with the wedge, so that the wedge forms a radial self-locking structure after assembly.

7. A pile connecting structure according to claim 6, characterized in that: The sealing structure includes a guide sleeve (520), a plurality of sealing rings (521) and a sealing gasket. The guide sleeve (520) is fixed to the bottom end face of the annular positioning protrusion (510) and is used to insert into the bottom area of ​​the annular insertion sleeve (310). The plurality of sealing rings (521) are arranged axially on the outer wall of the guide sleeve (520). The sealing gasket is disposed on the bottom end face of the annular positioning protrusion (510) and abuts against the annular end face (320) to form an end face seal.

8. The pile connecting structure according to claim 1, characterized by: The fixing structure includes a plurality of locking components evenly arranged along the circumference, each of the locking components including a locking bolt (110) penetrating the upper end plate structure (100) and the lower end plate structure (130) and a nut (120) cooperating therewith.

9. The pile connecting structure according to claim 6, characterized by: The wedge is a radially inserted inclined wedge structure, and its wedge-shaped inclined surface matches the mating surface of the first through hole (530) and / or the second through hole (330) to enhance the radial clamping force when subjected to axial pressure.

10. The pile connecting structure according to claim 7, characterized by: It also includes a shoulder structure (400), which includes an annular shoulder (420) and a metal gasket (410). The annular shoulder (420) is disposed on the end face of the mating side of the lower baffle structure, and the metal gasket (410) is disposed on the end face of the mating side of the upper baffle structure. The annular shoulder (420) is used to abut against the metal gasket (410).

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