Concrete precast pile mechanical connecting piece

Abstract

According to the concrete precast pile mechanical connecting piece, the pile end plate and the pile hoop are welded, prefabricated and formed through the connecting piece, the temporary slurry sealing ring is arranged between the pile end plate and the pile hoop to form a regular connecting clamping groove structure, and the single-opening connecting clamp which has micro-elasticity, can be opened moderately and is good in integrity is matched; and quick and reliable mechanical connection between the precast piles is realized. The problem of slurry leakage of the clamping groove part in the prefabrication process is effectively solved through cooperation of the linking piece and the temporary slurry sealing ring, and the forming quality and the size precision of the connecting clamping groove are ensured; due to the design of the integral connecting hoop with the opening, enough structural strength and circumferential constraining force are guaranteed, the installation process is simplified through the micro-elasticity of the connecting hoop, and on-site operation is more convenient and faster; and the selectable weldable end plate and the anti-slip tooth surface design further enhance the multi-element adaptability and the anti-rotation capability of the connection. According to the method, the comprehensive performance and economical efficiency of precast pile connection are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of reinforced concrete precast pile foundation connection technology, and in particular to a mechanical connector for precast concrete piles. Background Technology

[0002] Precast concrete piles, such as pipe piles, hollow square piles, solid square piles, and various irregularly shaped piles, have been widely used in various infrastructure construction fields, including industrial and civil buildings, municipal engineering, metallurgy, ports, and highways, due to the advantages of stable quality and rapid construction brought about by factory production. With the continuous development of engineering needs, the requirements for pile foundation performance are also increasing, especially under conditions of uplift loads (tension resistance), such as wind power foundations and anti-buoyancy of underground structures in areas with frequent changes in groundwater levels. In these cases, the vertical tensile bearing capacity of the pile body has become a key design indicator.

[0003] Currently, the mainstream methods for connecting precast pile segments in engineering mainly include welding and some mechanical connections. Welding connections are achieved by butt-joining the end plates of adjacent pile segments and then welding them at the bevel of the end plates. Although this method is widely used, it has many drawbacks: First, the quality of on-site welding is greatly affected by the operator's skill and weather conditions (such as wind and rain), making it difficult to guarantee the internal quality and uniformity of the weld, and posing risks of defects such as incomplete welds and slag inclusions, directly affecting the connection strength and structural safety; second, the welding process is time-consuming, including multiple stages such as preheating, welding, heat preservation, and cooling, significantly affecting construction efficiency; third, the weld area is prone to corrosion in complex soil electrolyte environments, making rust prevention difficult and posing a challenge to long-term durability.

[0004] To overcome the shortcomings of welded connections, mechanical connection methods have been gradually proposed and applied. Some existing mechanical connection schemes, such as using multiple independent socket-type connectors and filling the joints with sealant, avoid on-site welding, but their stress patterns often fail to form a coherent stress system with the pile body, leading to stress concentration, limited pull-out resistance, and difficulty in meeting stringent pull-out design requirements. Other connection schemes using integral clamps or sleeves, while potentially ensuring structural strength, often result in bulky components, increased material usage, and higher costs. Furthermore, they place extremely high demands on the manufacturing precision of the precast piles and connectors, as well as the accuracy of on-site installation alignment, posing significant challenges to production and construction. For example, existing technologies with complex grooves in the end plates are prone to grout leakage during precast concrete pouring, leading to groove blockage or dimensional deviations, making on-site installation of the connecting clamps exceptionally difficult, or even impossible. In addition, some split clamp designs, while reducing the weight of individual components, increase the number of parts to be assembled on-site and the complexity of the operation. Multiple connection interfaces may also introduce additional weak points.

[0005] Therefore, the urgent technical problem to be solved in this field is: how to provide a mechanical connection scheme that is reasonably constructed, cost-controllable, easy to prefabricate and easy to install on site, while ensuring that the connection between precast pile segments has high tensile strength, high reliability and durability, so as to overcome the many defects of existing welded connections, such as unstable quality and low efficiency, as well as existing mechanical connection schemes, such as bulky structure, high cost, easy leakage of grout, and difficult installation. Summary of the Invention

[0006] The purpose of this invention is to provide a mechanical connector for precast concrete piles to solve the problems existing in the prior art.

[0007] To achieve the above objectives, the present invention provides the following solution: This invention provides a mechanical connector for precast concrete piles, comprising: Precast piles, wherein prestressed steel bars are provided inside the precast piles; A pile end plate, which is embedded in the pile end surface of the precast pile, and the pile end plate is formed with end plate holes for connecting with the prestressed steel bars; A pile sleeve is pre-embedded in the pile end of the precast pile. The pile sleeve has at least one circumferentially formed anti-pull-out reinforcement bar for engaging with the pile body. Before precasting, the pile end plate is welded to the pile sleeve via a first connector and a second connector to form a single unit. The first connector and the second connector are used to create a gap of a predetermined width between the pile end plate and the pile sleeve. The bottom surface of the pile end plate, the pile sleeve, and the concrete within the pile sleeve together form a connecting groove. If there are special requirements for the project, the pile sleeves can also be removed; A connecting clamp is fitted into the connecting groove to connect the pile end plates of the upper and lower sections of the precast pile into a whole. The connecting clamp has at least one connecting clamp opening. A temporary grouting sealing ring is installed in the gap before the precast pile is precast; the temporary grouting sealing ring is removed after the precast pile is precast.

[0008] Preferably, the bottom surface of the pile end plate is formed with an L-shaped groove in a closed loop, and the upper end of the pile sleeve is connected to the pile end plate through the second connector to form the gap together; after the precast pile is prefabricated, the L-shaped groove and the concrete in the pile sleeve cooperate to form the connecting groove.

[0009] Preferably, a rectangular notch-shaped connecting groove is machined on the circumference of the pile end plate, immediately adjacent to its bottom surface.

[0010] Preferably, after the connecting clamp is inserted into the connecting groove, the two ends of the opening of the connecting clamp are connected to the side of the pile end plate by welding to form a weld between the clamp and the end plate.

[0011] Preferably, the top surface of the pile end plate is machined with a welding bevel to form a weldable pile end plate. When two precast piles are joined together, the welding bevels cooperate to form a welding groove, and the welding groove is provided with a connecting weld to weld the two pile end plates together.

[0012] Preferably, the connecting clamp is an integral ring-shaped component with an opening; the connecting clamp has two buckling parts for engaging with the corresponding connecting slots of the upper and lower precast piles, and a clamping cavity is formed between the two buckling parts for securing the periphery of the pile end plate of the two precast piles.

[0013] Preferably, the L-shaped groove is machined with anti-slip teeth; the snap-fit ​​part is machined with anti-slip teeth for engaging with the anti-slip teeth. Alternatively, an interference fit bevel is machined in the L-shaped groove; an interference fit bevel is machined on the buckle part for engaging with the interference fit bevel, the bevel angle on the end plate can be set to about 10°, and the bevel angle of the clamp is one degree smaller than that of the end plate, set to about 9°.

[0014] Preferably, the thickness of the connecting clamp and the dimensions of the buckle are determined by finite element analysis of the tensile bearing capacity of a thin plate. The finite element analysis equation for the tensile bearing capacity of a thin plate is as follows: ; in, The minimum inner radius of the clamp. The outer radius of the clamp. This refers to the bending stiffness of the clamp plate.

[0015] Preferably, the thickness of the connecting clamp is not greater than the thickness of the pile end plate, so that the connecting clamp has slight elasticity in the circumferential direction, and the circumferential dimension can be increased by widening the opening of the connecting clamp to facilitate installation.

[0016] Preferably, the two ends of the opening of the connecting clamp are fixedly connected by a clamp connecting assembly; the clamp connecting assembly includes a connecting plate and a connecting bolt; the opening end of the connecting clamp is machined with a circular bolt hole or an elongated bolt hole, and the connecting bolt is screwed into the elongated bolt hole.

[0017] The present invention achieves the following beneficial technical effects compared to the prior art: This invention provides a mechanical connector for precast concrete piles. It utilizes a precast pile end plate and pile sleeve, welded together with a connector, and incorporates a temporary grouting seal to form a regular connecting groove. Combined with a single-opening connecting clamp that is slightly elastic, can open moderately, and has good overall integrity, this achieves a rapid and reliable mechanical connection between precast piles. This connector features fast connection speed, high construction efficiency, strong pull-out resistance, good safety and reliability, and excellent durability. Specifically, the combination of the connector and the temporary grouting seal effectively solves the problem of grout leakage at the groove location during precasting, ensuring the forming quality and dimensional accuracy of the connecting groove, laying the foundation for smooth installation of the clamp on site. The integral, open-type connecting clamp design ensures sufficient structural strength and circumferential restraint while its slight elasticity simplifies the installation process, reducing stringent requirements for installation accuracy and making on-site operation more convenient. Furthermore, the optional weldable end plate and anti-slip toothed surface design further enhance the connection's versatility and anti-rotation capability. This invention effectively solves the technical problems of traditional welding connection, such as difficulty in controlling quality and low efficiency, as well as the existing mechanical connection scheme, such as complex structure, high cost, easy leakage of grout, and difficult installation, and significantly improves the comprehensive performance and economy of precast pile connection. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a structural schematic diagram of the pile-to-pile connection of the present invention and a partially enlarged schematic diagram of point I; Figure 2 yes Figure 1 A partially enlarged cross-sectional view (1-1) of the schematic diagram of the weldless pile end plate splicing of the present invention, type 1 of the slot; Figure 3 yes Figure 1 A partial enlarged cross-sectional view of the weldable pile end plate of the present invention, type 1, groove, in the present invention, shown in section 1-1; Figure 4 yes Figure 1 A partial enlarged cross-sectional view of the weldless pile end plate of the present invention, type 2, in the present invention, shown in section 1-1; Figure 5 yes Figure 1 A partial enlarged cross-sectional view of the weldable pile end plate of the present invention, slot type 2, in the present invention, shown in section 1-1; Figure 6 This is a schematic diagram of the circular and square end plates of the present invention; Figure 7 This is a side view of the end plate, clamp, and sealing ring being installed during the production of this invention; Figure 8 This is a top view of the end plate, clamps, and sealing rings during the production of this invention; Figure 9 yes Figure 7 and Figure 8 Schematic diagram of the center seal grout sealing ring; Figure 10 yes Figure 8 Cross-sectional view of the weldable pile end plate of slot type 1 and a partially enlarged schematic diagram of section III; Figure 11 This is a schematic diagram of the connection structure between the end plate and the pile sleeve of the present invention; Figure 12 This is a schematic diagram of the structure of the slot type 1 of the present invention with a partial pile end plate with anti-slip tooth surface; Figure 13 This is a schematic diagram and a side sectional view of the groove-type pile sleeve of the present invention; Figure 14 yes Figure 8 Cross-sectional view of the weldless pile end plate of slot type 2 and a partially enlarged schematic diagram of point IV; Figure 15 yes Figure 8 Cross-sectional view of the weldable pile end plate of slot type 2 and a partially enlarged schematic diagram of section V; Figure 16 This is a schematic diagram of the structure of the groove type 2 of the present invention, which has anti-slip toothed surface and partial pile end plate with interference fit surface; Figure 17 This is a schematic diagram of the circular and square connecting clamps of the present invention; Figure 18 yes Figure 21 Cross-sectional structural diagram; Figure 19 yes Figure 21 A schematic diagram of a connecting clamp with anti-slip teeth and an interference fit surface; Figure 20 This is an installation diagram of the circular and square connecting clamps of the present invention when connecting piles; Figure 21 This is a schematic diagram of the structure of the circular and square connecting clamps welded together in the present invention 1; Figure 22 This is a schematic diagram of the structure of the circular and square connecting clamps welded together in the second manner according to the present invention; Figure 23 This is a schematic diagram of the circular and square connecting clamps with threaded holes of the present invention; Figure 24 This is a schematic diagram of the connection structure of the present invention with a threaded hole connecting clamp. Detailed Implementation

[0020] The serial numbers assigned to components in this document, such as "first," "second," etc., are merely used to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention.

[0021] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The purpose of this invention is to provide a mechanical connector for precast concrete piles, which aims to solve the problems of unstable quality and low efficiency of existing welded connections, as well as the problems of bulky structure, easy grout leakage, and difficult installation of existing mechanical connection schemes.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example 1: Please see Figure 1 , Figure 6 , Figure 7 , Figure 8 , Figure 20 and Figure 24The basic connecting components of this invention include a pile end plate 2 embedded in the end face of the precast pile 1, a pile sleeve 3 embedded in the end of the precast pile 1, a connecting clamp 4 for finally connecting the two pile sections, a temporary sealing ring 5 used during prefabrication, and a first connecting member 6a and a second connecting member 6b for connecting the pile end plate 2 and the pile sleeve 3. The pile end plate 2 has multiple end plate holes 2a formed on it for anchoring to the prestressed steel bars 11 inside the precast pile 1 during prefabrication. The pile sleeve 3 has at least two circumferential pull-out ribs 3a formed on it. These ribs are embedded into the pile body after concrete pouring, greatly enhancing the bonding force between the pile sleeve 3 and the concrete pile body, thereby significantly improving the pull-out resistance of the connection node area.

[0026] A core aspect of this invention lies in the synergistic effect of the pile end plate 2, the pile sleeve 3, and the temporary grouting sealing ring 5 during the prefabrication stage. For example... Figure 7 , Figure 8 , Figure 10 , Figure 14 and Figure 15 As shown, before the precast pile 1 is produced, the pile end plate 2 and the pile sleeve 3 are welded and fixed together as a single sub-component using the first connector 6a and the second connector 6b. This welding connection creates a gap of a predetermined width between the pile end plate 2 and the pile sleeve 3. Subsequently, a temporary sealing ring 5 (whose shape can be seen in the diagram) is installed in this reserved gap. Figure 9 The function of the temporary grout sealing ring 5 is to effectively prevent cement grout from entering the slot space formed by the pile end plate 2 and the pile sleeve 3 during the concrete pouring and vibration process, which will be used to install the connecting clamp 4 in the future. This ensures that the connecting slot K1 is clean and dimensionally accurate after the pile body curing is completed. After the precast pile 1 has cured and reached its strength, the temporary grout sealing ring 5 can be removed. At this time, a regular and continuous connecting slot K1 is formed by the bottom surface of the pile end plate 2, a specific part of the pile sleeve 3, and the concrete inside the pile sleeve 3. Figures 2 to 5 As shown.

[0027] Regarding the specific configuration of the connecting slot K1, this invention provides at least two preferred embodiments. The first slot configuration can be found in [reference needed]. Figure 2 , Figure 3 , Figure 10 , Figure 12 and Figure 13 In this configuration, an L-shaped groove 21 is machined in a closed loop around the bottom perimeter of the pile end plate 2. The upper end of the pile sleeve 3 is welded to the pile end plate 2 via a second connector 6b, forming a gap between them for installing a temporary grout sealing ring 5. After prefabrication, the temporary grout sealing ring 5 is removed, and the L-shaped groove 21 of the pile end plate 2 and the concrete surface inside the pile sleeve 3 together constitute the connecting groove K1. A second type of groove can be found in [reference needed]. Figure 4 , Figure 5 , Figure 14 , Figure 15 and Figure 16 In this configuration, the connecting groove K1 is directly machined onto the circumferential surface of the pile end plate 2, specifically, a rectangular (or approximately rectangular) notch-shaped structure is machined around the bottom surface of the pile end plate 2. The first connector 6a is used to maintain the relative position of the pile end plate 2 and the pile sleeve hoop 3 and to form a gap for installing the temporary sealing ring 5.

[0028] Depending on the structure of its top, the pile end plate 2 can be divided into non-welded types (such as...). Figure 2 , Figure 4 , Figure 14 (as shown) and weldable (such as) Figure 3 , Figure 5 , Figure 10 , Figure 15 (As shown). For weldable pile end plates, a welding bevel 22 is machined around the top surface. (See figure). Figure 1 , Figure 3 and Figure 5 As shown, when the upper and lower precast pile sections 1 are joined together, the welding bevels 22 on the pile end plates 2 of the two pile sections are aligned with each other, forming a complete welding groove K2. During construction, welding can be performed first in this welding groove K2 to form a connecting weld F2, achieving a preliminary connection between the two pile end plates. This provides additional safety and connection strength for subsequent operations. For non-welded pile end plates, this welding step is unnecessary, and mechanical connection can be performed directly.

[0029] Another core component of this invention is the connecting clamp 4. (See attached diagram) Figures 17 to 24 As shown, the connecting clamp 4 is preferably an integral annular component (which can be circular or square to accommodate different pile cross-sectional shapes) with a connecting clamp opening 41. The connecting clamp 4 has two snap-fit ​​parts 411, and a clamping cavity 412 is formed between these two snap-fit ​​parts 411 to accommodate and clamp the periphery of the pile end plate 2 of the upper and lower precast pile 1. The thickness of the connecting clamp 4 is designed not to exceed the thickness of the pile end plate 2, which gives the connecting clamp 4 a certain degree of slight elasticity in the circumferential direction. Figure 20 As shown, during installation, a tool (such as open-end pliers) can be used to pry open the opening 41 of the connecting clamp slightly, increasing its circumferential dimension, so that the connecting clamp 4 can be fitted onto the pile head of the lower pile section first. After the upper pile section is in place, the connecting clamp 4 is moved to the position where the connecting grooves K1 of the upper and lower pile sections are aligned. The tool is then released, and the connecting clamp 4, relying on its own elastic restoring force, tightly locks into the connecting grooves K1 on both sides, completing the mechanical locking.

[0030] To ensure sufficient strength of the connecting clamp 4 under stress, its thickness and critical dimensions of the snap-fit ​​part 411 need to be precisely calculated and optimized through finite element analysis of the tensile bearing capacity of thin plates. The mechanical equations upon which this analysis is based are: ; in, The minimum inner radius of the clamp. The outer radius of the clamp. The bending stiffness of the clamp plate is given. By solving the system of equations, the minimum thickness and clamp dimensions required to meet the design tensile load can be determined, thereby achieving material economy while ensuring safety.

[0031] After the connecting clamp 4 is inserted into the connecting slot K1, its opening needs to be secured to prevent it from loosening during long-term use. This invention provides at least two securing methods. The first method is as follows... Figure 21 As shown, the two ends of the connecting clamp opening 41 are directly welded to the side of the pile end plate 2 below (or above) to form the clamp-end plate weld F4. The second method is as follows... Figure 22 , Figure 23 and Figure 24 As shown, a separate clamp connection assembly 7 is used for mechanical connection. This assembly includes a connecting plate 71 and two connecting bolts 72. The clamp connection assembly 7 has two bolt holes, one circular bolt hole 71a and the other elongated bolt hole 71b. During installation, the connecting bolt 72 is passed through the elongated bolt hole 71b, and the two ends of the opening are tightened and fixed. The elongated bolt hole 71b provides installation adjustment margin, facilitating on-site hole alignment and tightening.

[0032] To further enhance the mechanical interlocking ability between the connecting clamp 4 and the pile end plate 2 and prevent relative rotation between them, the present invention also includes an anti-slip structure. For example... Figure 12 , Figure 16 and Figure 19 As shown, an anti-slip toothed surface 21a can be machined in the L-shaped groove 21 of the pile end plate 2 (taking the first type of groove as an example). Correspondingly, an anti-slip toothed surface 41a that mates with it is also machined on the snap-fit ​​part 411 of the connecting clamp 4. When the connecting clamp 4 is tightened, the anti-slip toothed surface 21a and the anti-slip toothed surface 21a mesh with each other, effectively resisting circumferential torque; as another embodiment, an interference fit inclined surface 21b can be machined in the L-shaped groove 21, and the angle of the inclined surface can be set to about 10°; an interference fit inclined surface 41b for mates with the interference fit inclined surface 21b is machined on the snap-fit ​​part 411, and the angle of the inclined surface can be set to about 9°, which can also achieve a similar effect.

[0033] The pile splicing process of the present invention can be briefly summarized as follows: For weldable pile end plates, butt welding can be performed first to form a connecting weld F2; then, the connecting clamp 4, which is pre-fitted onto the pile head of the lower pile section, is moved up to the alignment of the connecting groove K1 of the upper and lower pile sections; its slight elasticity is used to make it snap into the groove; finally, welding (forming the clamp and end plate weld F4) or using the clamp connecting assembly 7 to tighten the connecting clamp opening 41 is selected according to the design, thereby quickly and reliably completing the mechanical connection of the two precast pile sections.

[0034] In summary, this invention fundamentally solves the problems of grout leakage and forming accuracy in the connecting groove K1 through the prefabricated integrated design of the pile end plate 2, pile sleeve 3, temporary grout sealing ring 5, and first connecting piece 6a and second connecting piece 6b; the single-opening, slightly elastic integral connecting clamp 4 design balances installation convenience and connection reliability; and the optional welding bevel 22, anti-slip tooth surface 21a, and various clamp fixing methods provide a flexible and robust connection solution, effectively improving the construction efficiency, tensile strength, and economy of prefabricated pile connections.

[0035] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0036] It should be noted that the components mentioned in the above embodiments are all general standard parts or components known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0037] This invention has illustrated its principles and implementation methods using specific examples. The descriptions of these embodiments are merely illustrative of the method and its core ideas; furthermore, those skilled in the art will recognize that modifications may be made to the specific implementation methods and application scope based on the principles of this invention. Therefore, the content of this specification should not be construed as limiting the invention.

Claims

1. A mechanical connector for precast concrete piles, characterised in that: The utility model relates to a precast pile (1) is equipped with prestressed reinforcement (11) in, pile end plate (2) is embedded in the pile end surface of precast pile (1), and the end plate hole (2a) for connecting with prestressed reinforcement (11) is shaped in pile end plate (2), pile sleeve hoop (3) is embedded in the pile end of precast pile (1), and at least one anti -pulling convex rib (3a) for being clamped into the pile body of precast pile (1) is shaped on the pile sleeve hoop (3) annularly, the first connecting piece (6a) and the second connecting piece (6b) are connected with the pile sleeve hoop (3) and are welded to be connected into an organic whole before precast pile precast, and the first connecting piece (6a) and the second connecting piece (6b) are used to make the gap with the predetermined width between the pile end plate (2) and the pile sleeve hoop (3), the bottom surface of the pile end plate (2), the pile sleeve hoop (3) and the concrete in the pile sleeve hoop (3) jointly form the connecting clamping groove (K1), the connecting clamping hoop (4) is clamped in the connecting clamping groove (K1), is used to connect the pile end plate (2) of the upper and lower two sections precast pile (1) and is connected into an organic whole, and the connecting clamping hoop (4) has at least one connecting clamping hoop opening (41), the temporary sealing circle of sealing grout (5) is installed in the gap before precast pile (1) precast, and the temporary sealing circle of sealing grout (5) is removed after precast pile (1) precast is completed. The bottom surface of the pile end plate (2) is peripherally shaped with an L-shaped notch (21), the upper end of the pile sleeve hoop (3) is connected with the pile end plate (2) through the second connecting piece (6b), and the L-shaped notch (21) and the concrete in the pile sleeve hoop (3) cooperatively form the connecting clamping groove (K1) after the precast pile (1) is precasted. The connecting clamping groove (K1) is processed on the surface of the pile end plate (2) adjacent to the bottom surface in a rectangular notch shape. After the connecting clamping hoop (4) is clamped into the connecting clamping groove (K1), the two ends of the connecting clamping hoop opening (41) are connected with the side surface of the pile end plate (2) through welding, forming a hoop and end plate weld (F4). The top surface of the pile end plate (2) is peripherally processed with a welding bevel (22), forming a weldable pile end plate, and the welding bevel (22) cooperatively constitutes a welding groove (K2) when the two sections of the precast pile (1) are butted, and the connecting weld (F2) for welding and connecting the two pile end plates (2) is arranged in the welding groove (K2). The connecting clamping hoop (4) is an integral annular member with the connecting clamping hoop opening (41), and the connecting clamping hoop (4) is provided with two buckle parts (411) for clamping into the corresponding connecting clamping grooves (K1) of the upper and lower two sections of the precast pile (1), and a clamping cavity (412) for clamping the periphery of the pile end plates (2) of the two sections of the precast pile (1) is formed between the two buckle parts (411).

2. A mechanical connection for concrete precast piles according to claim 1, characterized in that: ​ 3. A mechanical connection for concrete precast piles according to claim 1, characterized in that: ​ 4. A mechanical connection for concrete precast piles according to claim 3, characterized in that: ​ 5. A mechanical connection for concrete precast piles according to claim 1, characterized in that: ​ 6. A mechanical connection for concrete precast piles according to claim 1, characterized in that: ​ 7. A mechanical connection for concrete precast piles according to claim 6, characterized in that: The L-shaped notch (21) is processed with an anti-skid tooth surface (21a); the buckle part (411) is processed with an anti-skid tooth part (41a) for matching with the anti-skid tooth surface (21a); Or, the L-shaped notch (21) is processed with an interference fit inclined surface (21b); the buckle part (411) is processed with an interference fit inclined surface (41b) for matching with the interference fit inclined surface (21b).

8. A mechanical connection for concrete precast piles according to claim 6, characterized in that: The thickness of the connecting clamp (4) and the size of the buckle part (411) are determined by thin plate tension bearing capacity finite element analysis, and the thin plate tension bearing capacity finite element analysis equation is: ； wherein, is the minimum inner radius of the clamp, is the outer radius of the clamp, is the bending stiffness of the clamp plate.

9. A mechanical connection for concrete precast piles according to claim 1, characterized in that: The thickness of the connecting clamp (4) is not greater than the thickness of the pile end plate (2), so as to make the connecting clamp (4) have micro-elasticity in the ring direction, and the ring direction size can be increased by expanding the connecting clamp opening (41), so as to facilitate installation.

10. A mechanical connection for concrete precast piles according to claim 1, characterized in that: Both ends of the connecting clamp opening (41) are fixedly connected through a clamp connecting assembly (7); the clamp connecting assembly (7) comprises a connecting plate (71) and a connecting bolt (72); the opening end of the connecting clamp (7) is processed with a circular bolt hole (71a) or a long strip-shaped bolt hole (71b), and the connecting bolt (72) is screwed into the long strip-shaped bolt hole (71b).

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