A core filling assembly for PHC pipe piles and its manufacturing process

Abstract

A core-filling assembly for PHC pipe piles includes multiple concrete core-filling flaps (2), a variable cross-section wedge (4), and a locking circular plate (5). The concrete core-filling flaps and the variable cross-section wedge are columnar structures. The multiple concrete core-filling flaps are arranged around the variable cross-section wedge and placed together inside the PHC pipe pile. The locking circular plate fixes the variable cross-section wedge. The concrete core-filling flaps, the variable cross-section wedge, and the locking circular plate are fixed by concrete pouring. This invention also provides a manufacturing process for the core-filling assembly for PHC pipe piles, including the arrangement of the concrete core-filling flaps around the circumference of the variable cross-section wedge and placing them together inside the PHC pipe pile. The variable cross-section wedge is locked by the locking circular plate and fixed by concrete pouring. Compared with traditional wet-filling on-site fabrication, this invention has significant advantages such as simple manufacturing process, short cycle, easy construction control, excellent quality, stable pull-out and shear bearing capacity, and enhanced interfacial bond strength between the core-filling concrete and the inner wall of the pipe pile.

Description

Technical Field

[0001] This invention belongs to the field of civil engineering pile foundations, specifically relating to a core-filling assembly for PHC pipe piles and its manufacturing process. Background Technology

[0002] Prestressed high-strength concrete pipe piles (PHC pipe piles) are characterized by high pile quality, high vertical bearing capacity per pile, strong adaptability to engineering geological conditions, and fast construction speed. They have been widely used in construction, highway, railway, and port projects. Essentially, a prestressed high-strength concrete pipe pile foundation is a prefabricated pile foundation structure system. It is a pile foundation system in which the prestressed pipe piles are placed in place and then connected to the pile cap by subsequent pouring of filler concrete. From the perspective of the stress on the pile head of a PHC pipe pile…

[0003] On the one hand, for box or raft foundations, PHC pipe piles may cause damage to all or one side of the pile foundations due to tension under horizontal seismic forces, wind loads, etc., in areas with abundant groundwater and for high-rise or tall structures.

[0004] On the other hand, under horizontal seismic action, the shear force at the bottom of the building is transmitted to the pile foundation through the pile cap, and the connection between the top of the pile foundation and the pile cap is subjected to horizontal force. The core-filling concrete serves as the connection node between the top of the pipe pile and the subsequently poured foundation cap. The axial tensile force borne by the pipe pile body is transmitted through the core-filling concrete, and the horizontal shear force borne by the top of the pipe pile is also shared by the core-filling concrete.

[0005] Currently, in engineering practice, the common practice is to fill the PHC pile borehole with reinforced concrete. The aim is to directly increase the shear capacity of the pile top and provide greater pull-out resistance for uplift piles. However, traditional wet concrete filling methods have problems:

[0006] (1) Traditional wet concrete filling includes the process of setting longitudinal steel bars and spiral stirrups for the filling part, and wet concrete pouring. The operation is complicated, the construction cycle is long, the construction is difficult to control, and the construction quality is difficult to guarantee.

[0007] (2) When the groundwater level at the construction site is high, water is filled into the holes of PHC pipe piles, making it difficult to achieve wet filling construction and ensuring the strength and quality of cast-in-place concrete.

[0008] (3) Under the current environmental pressure, the core filling part of the pipe hole is still poured on site, which causes more serious environmental pollution and is not suitable for the requirements of the current construction industrialization.

[0009] (4) Traditionally, the core filling part is manually poured on site. The core filling concrete is difficult to cure, and the compressive strength of the core filling concrete is not easy to guarantee. When the core filling part of the pile hole provides the tensile bearing capacity of the pile foundation, it mainly depends on the consolidation strength of the core filling concrete and the interfacial bond strength between the core filling concrete and the inner wall of the pipe pile. When the core filling concrete is poured on site, the consolidation strength of the core filling concrete and the interfacial bond strength are not easy to guarantee. The consolidation dispersion of the core filling part of the pile hole filled with reinforced concrete in the on-site construction of the core filling structure of PHC pile body pipe hole is relatively large.

[0010] To address the problems of cumbersome and time-consuming traditional wet core filling methods, difficulty in construction control, difficulty in quality assurance, and unstable pull-out bearing capacity, and to promote the prefabricated construction of PHC pipe pile foundations. Summary of the Invention

[0011] To address the problems of cumbersome on-site fabrication, long cycle, difficult construction control, quality assurance, and unstable tensile and shear bearing capacity in traditional wet core filling methods, and to promote the prefabricated construction of PHC pipe pile foundations, especially considering the issue of unstable tensile and shear bearing capacity, this invention provides a core filling assembly for PHC pipe piles, comprising: multiple fabricated concrete core filling flaps 2, variable cross-section wedges 4, and locking circular plates 5.

[0012] The concrete-filled valve 2 and the variable cross-section wedge 4 are columnar structures;

[0013] Multiple concrete core-filling valves 2 are arranged around the variable cross-section wedge rod 4 and placed together in the pipe hole at the upper end of the PHC pipe pile. The locking circular plate 5 fixes the variable cross-section wedge rod 4 to the top of the PHC pipe pile.

[0014] The concrete-filled valve 2, the variable cross-section wedge 4, and the locking circular plate 5 are fixed by concrete pouring.

[0015] Preferably, the variable cross-section wedge 4 includes: a constant cross-section rod and a variable cross-section rod;

[0016] The constant cross-section rod is a column structure with texture on the outside;

[0017] The variable cross-section rod is a tapered straight rod with a smooth outer surface;

[0018] The diameter of the uniform cross-section bar is determined based on the pull-out bearing capacity of the PHC pipe pile, the pull-out force on the uniform cross-section bar, and the profile of the uniform cross-section bar.

[0019] The diameter of the variable cross-section bar is determined based on the concrete core flap 2, the pull-out bearing capacity of the PHC pipe pile, and the profile of the variable cross-section bar.

[0020] Preferably, the concrete core-filling flap 2 has a fan-shaped cross-section, with a notch at the center of the fan shape.

[0021] Preferably, the number of concrete core-filling flaps 2 is determined by the angle of the sector, and all the concrete core-filling flaps 2 enclose a circular cylinder. The notch of the concrete core-filling flaps 2 forms the central hole of the circular cylinder, and the variable cross-section wedge 4 is located inside the central hole.

[0022] Preferably, the number of concrete core-filled flaps 2 is not less than 3.

[0023] Preferably, the concrete-filled flap 2 includes:

[0024] A constant-section filler flap and a variable-section filler flap composed of multiple longitudinal bars 7, stirrups 8, and tie bars 9.

[0025] Multiple longitudinal ribs 7 are configured with a fan-shaped cross-section;

[0026] Stirrups 8 are placed around the longitudinal reinforcement 7;

[0027] The tie bars 9 are distributed radially in the sector of the cross-section and are connected to the longitudinal bars 7 and the stirrups 8;

[0028] The fan-shaped notch area of ​​the equal cross-section core-filled valve is the same;

[0029] The variable cross-section core-filled valve has at least two cross-sections with different notch areas;

[0030] The lengths of the variable cross-section core-filled valve and the constant cross-section core-filled valve are set according to the pull-out bearing capacity of the PHC pipe pile, respectively.

[0031] The minimum cross-section of the central hole in the concrete-filled valve 2 is smaller than the maximum cross-section of the variable cross-section wedge 4;

[0032] The length of the longitudinal reinforcement 7 is the same as the length of the concrete core-filling valve 2. The equal-section core-filling valve is matched with the equal-section rod, and the variable-section core-filling valve is matched with the variable-section rod. The length of the equal-section core-filling valve is less than the length of the equal-section rod, and the length of the variable-section core-filling valve is greater than the length of the variable-section rod.

[0033] Preferably, the bottom surface of the variable cross-section core-filled valve is located below the bottom surface of the variable cross-section rod and is at a distance from it.

[0034] Preferably, the locking circular plate 5 is made of high-strength steel with holes, its inner diameter matches the diameter of the uniform cross-section rod, and the outer diameter of the locking circular plate 5 is larger than the inner diameter of the PHC pipe pile.

[0035] Based on the same inventive concept, the present invention also provides a manufacturing process for a core-filling assembly for PHC pipe piles, comprising:

[0036] The concrete core-filled valve 2 is arranged around the circumference of the variable cross-section wedge rod 4 and placed together in the pipe hole at the upward end of the PHC pipe pile.

[0037] The upper end of the variable cross-section wedge rod 4 protrudes from the top of the PHC pipe pile and is locked by the locking circular plate 5;

[0038] The concrete core flap 2, the variable cross-section wedge rod 4, and the locking circular plate 5 are fixed by integral concrete casting.

[0039] Preferably, the diameter of the variable cross-section wedge 4 is designed based on the magnitude of the pull-out force borne by the PHC pipe pile and the magnitude of the pull-out force borne by the variable cross-section wedge 4, as well as the profile requirements of the variable cross-section wedge 4.

[0040] Preferably, the length of the circular column formed by the concrete core flap 2 is designed based on the magnitude of the pull-out force borne by the PHC pipe pile.

[0041] Preferably, the fabrication of the variable cross-section wedge 4 includes:

[0042] The length of the variable cross-section wedge rod 4 is designed based on the length of the circular column formed by the concrete-filled valve 2.

[0043] The profile is machined according to the diameter and length of the variable cross-section wedge 4 to obtain the variable cross-section wedge 4, which includes a constant cross-section bar and a variable cross-section bar;

[0044] The length of the variable cross-section wedge 4 includes the lengths of both the constant cross-section rod and the variable cross-section rod.

[0045] Preferably, the fabrication of the concrete-filled flap 2 includes:

[0046] The dimensions of the concrete filling valve 2 are designed based on the dimensions of the variable cross-section wedge 4, the dimensions of the PHC pipe pile, and the magnitude of the upward pull force borne by the PHC pipe pile. The external mold of the concrete filling valve 2 is selected according to the PHC pipe pile.

[0047] Cut multiple longitudinal reinforcement bars 7 according to the length of the concrete core flap 2;

[0048] Inside the mold outside the concrete core flap 2, multiple longitudinal ribs 7 are arranged in a fan-shaped cross-section along the length of the concrete core flap 2.

[0049] The longitudinal reinforcement 7 is surrounded by stirrups 8 and tied in the radial direction of the cross-section by tie bars 9;

[0050] Concrete is poured into the external mold, and after curing, consolidation and demolding, concrete core-filled valve 2, including equal cross-section core-filled valve and variable cross-section core-filled valve, is obtained;

[0051] The constant cross-section core-filled valve is fitted with the constant cross-section rod, and the variable cross-section core-filled valve is fitted with the variable cross-section rod;

[0052] The dimensional parameters of the concrete core-filled flap 2 include: the length of the concrete core-filled flap 2, the sector angle of the cross-section of the concrete core-filled flap 2, the sector angle, the sector radius, and the size of the notch at the center.

[0053] Preferably, the manufacturing of the locking circular plate 5 includes:

[0054] The dimensions of the locking circular plate 5 are designed based on the dimensions of the variable cross-section wedge 4 and the inner diameter of the PHC pipe pile and its bearing capacity and / or pull-out force requirements.

[0055] The high-strength steel material is cut according to the dimensional parameters of the locking circular plate 5;

[0056] The cut high-strength steel material is machined to produce the inner and outer diameters of the locking circular plate 5 according to the inner diameter of the PHC pipe pile and the diameter of the equal cross-section rod, thus obtaining the locking circular plate 5.

[0057] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0058] This invention provides a core-filling assembly for PHC pipe piles, comprising: multiple concrete core-filling flaps 2, variable cross-section wedges 4, and locking circular plates 5. The concrete core-filling flaps 2 and variable cross-section wedges 4 are columnar structures. The multiple concrete core-filling flaps 2 are arranged around the variable cross-section wedges 4 and placed together within the borehole at the upward-facing end of the PHC pipe pile. The locking circular plates 5 fix the variable cross-section wedges 4 to the top of the PHC pipe pile. The concrete core-filling flaps 2, variable cross-section wedges 4, and locking circular plates 5 are fixed by concrete pouring. Compared to traditional wet-filling methods in the prior art, the concrete core-filling assembly for PHC pipe piles provided by this invention has significant advantages in terms of superior quality, stable tensile and shear bearing capacity, and enhanced interfacial bond strength between the core-filling concrete and the inner wall of the pipe pile.

[0059] This invention also provides a manufacturing process for a core-filling assembly for PHC pipe piles, comprising: arranging a manufactured concrete core-filling flap 2 around the circumference of a variable cross-section wedge rod 4, and placing them together inside the pipe hole at the upward-facing end of the PHC pipe pile; the upper end of the variable cross-section wedge rod 4 protruding from the top of the PHC pipe pile and locked by a locking circular plate 5; and fixing the concrete core-filling flap 2, the variable cross-section wedge rod 4, and the locking circular plate 5 by integrally casting concrete. Compared with the traditional wet-filling on-site fabrication methods in the prior art, the manufacturing process of the core-filling assembly for PHC pipe piles provided by this invention has significant improvements in terms of simple manufacturing process, short construction period, and easy construction control, resulting in significant advantages. Attached Figure Description

[0060] Figure 1 This invention provides a schematic diagram of a core-filling assembly for PHC pipe piles.

[0061] Figure 2 A schematic diagram of a variable cross-section wedge structure provided by the present invention;

[0062] Figure 3 A schematic diagram of a core-filled valve reinforcement structure for a PHC pipe pile provided by the present invention;

[0063] Figure 4 Provided by the present invention Figure 1 A top-down view of points 11-12;

[0064] Figure 5 Provided by the present invention Figure 1 A schematic diagram of the cross-sectional profile of the structure at positions 22-23;

[0065] Figure 6 Provided by the present invention Figure 1 A schematic diagram of the cross-sectional profile of the structure at positions 33-34;

[0066] Figure 7 Provided by the present invention Figure 1 A schematic diagram of the cross-sectional profile of the structure at positions 44-45;

[0067] Figure 8 This invention provides a process flow diagram for manufacturing a core-filling assembly for PHC pipe piles.

[0068] Explanation of icon numbers:

[0069] 1-PHC pipe pile body; 2-Concrete core filling valve; 3-Pipe pile end plate; 4-Variable cross-section wedge rod; 5-Locking circular plate; 6-Anti-loosening nut; 7-Longitudinal reinforcement; 8-Stirrup; 9-Tie bar; 101-Core filling length; 102-Constant cross-section rod; 103-Variable cross-section rod; 104-Maximum cross-sectional diameter at the bottom of the wedge segment; 105-Pipe pile inner diameter; 106-Pipe pile outer diameter. Detailed Implementation

[0070] This invention proposes a prefabricated concrete core-filled composite component. (See attached diagram) Figure 1 and attached Figure 3As shown, the main components include multiple fan-shaped precast high-strength concrete flaps 2, variable cross-section wedges 4, pipe pile end plates 3, locking circular plates 5 and anti-loosening nuts 6, longitudinal bars 7 and stirrups 8. By setting special structural forms and design parameters, combined with assembly tensioning anchoring and locking measures, the precast assembled concrete core-filled composite components and PHC pipe piles are quickly connected, while meeting the requirements of pile head pull-out bearing capacity and horizontal shear bearing capacity. This invention provides a novel precast concrete core filling method for prestressed high-strength concrete pipe piles (PHC pipe piles). It overcomes the challenges of traditional wet concrete pouring methods, which are cumbersome, time-consuming, and difficult to control in terms of quality. These challenges include high groundwater levels at the construction site, water filling within the PHC pipe pile borehole, difficulties in wet core filling, and challenges in ensuring the strength and quality of the cast-in-place concrete. Traditional wet concrete core filling methods also face difficulties in connecting with precast foundations or caps, and are difficult to cure, resulting in inconsistent compressive and interfacial bond strengths and significant dispersion. This invention enables rapid core filling for PHC pipe pile foundations, adapting to the fast pace of precast construction. It shortens the construction cycle, improves efficiency, enhances the interfacial compressive and bond strengths between the core concrete and the inner wall of the pipe pile, reduces dispersion, and ensures stable core filling quality. It is a novel component form that facilitates rapid connection with precast piles and caps.

[0071] To better understand this invention, the following description, in conjunction with the accompanying drawings and examples, will further illustrate the invention.

[0072] Example 1:

[0073] This invention provides a core filling assembly for PHC pipe piles. The product of this invention can be used for core filling needs of PHC pipe piles in various occasions, and has particular advantages in combination with prefabricated reinforced concrete foundations.

[0074] As attached Figure 1 As shown, the precast assembled concrete core-filling component comprises three fan-shaped precast high-strength concrete core-filling flaps 2, which together form a circular cylindrical core-filling component. The length of the circular cylinder is the core-filling length 101, and the outer diameter of the circular cylinder is slightly smaller than the inner diameter of the central hole in the PHC pipe pile body 1, with a difference of 7-10 mm. The core-filling component, formed by the three concrete core-filling flaps 2, has a central hole at its center. The upper diameter of the central hole in the core-filling component enclosed by the concrete core-filling flaps 2 is smaller, as shown in the attached diagram. Figure 2As shown, the variable cross-section wedge 4 includes a constant cross-section rod and a variable cross-section rod. The lower diameter of the variable cross-section rod 103 gradually increases at a certain angle within a certain length range, forming a partially wedge-shaped central hole. The angle between the wedge-shaped inclined surface of the wedge-shaped central hole and its longitudinal cross-section is determined according to the force on the concrete core-filling valve 2 and the PHC pipe pile foundation, and meets the angle requirements of the engineering construction. The total length of the concrete core-filling valve 2, that is, the core length 101, is determined according to the vertical tensile force on the pile foundation. The diameter of the variable cross-section wedge 4 is designed based on the magnitude of the uplift force borne by the PHC pipe pile and the variable cross-section wedge 4, as well as the profile requirements of the variable cross-section wedge 4. The length of the circular cylinder formed by the concrete core-filling valve 2 is designed based on the magnitude of the uplift force borne by the PHC pipe pile body 1.

[0075] As attached Figure 1 As shown, the variable cross-section wedge rod 4 is inserted into the variable cross-section central hole of the core-filling component formed by the enclosing of three concrete flaps 2. The diameter of the variable cross-section wedge rod 4 is slightly smaller than the diameter of the wedge-shaped central hole of the concrete core-filling flap 2, with a difference of 5 mm. The upper half of the variable cross-section wedge rod 4, the constant cross-section rod 102, is a fully threaded steel rod. A locking circular plate 5 and a fastening anti-loosening nut 6 are fitted on the pipe pile end plate 3. The variable cross-section wedge rod 4 can be a variable cross-section wedge-shaped screw rod; the locking circular plate 5 is a steel fixed circular steel plate; and the anti-loosening nut 6 is a locking nut.

[0076] During construction, gaps exist between the precast concrete core-filling flaps 2 and the inner wall of the PHC pipe pile body 1, and between the three concrete core-filling flaps 2 and the variable cross-section wedge rod 4 at the center of the core-filling component. The variable cross-section wedge rod 4 can be a variable cross-section wedge-shaped round steel bar. All gaps are filled by pressure penetration of cement-based high-strength concrete grout. Simultaneously, a hollow jack is used to pre-apply a pull-out force to the variable cross-section wedge rod 4 at the center of the core-filling component. The wedge-shaped section in the core-filling component exerts radial or perpendicular pressure on the precast concrete core-filling flaps 2, thereby achieving pressure between the precast concrete core-filling flaps 2 and the inner wall of the PHC pipe pile body 1, thus improving the bonding strength of the concrete interface in the gaps. After pre-tensioning, a locking round plate 5, together with the pipe pile end plate 3, locks the fully threaded end of the variable cross-section wedge rod 4, and the anti-loosening nut 6 is tightened.

[0077] As attached Figures 3-7As shown, this embodiment includes three precast high-strength concrete core-filling flaps 2. The plane angle of the concrete core-filling flaps 2 is 120°. The three concrete core-filling flaps 2 together form a core-filling component of a circular column, with a circular hole at the center of the column. The concrete core-filling flaps 2 are non-uniform cross-section components, and their lower half varies with the cross-sectional diameter of the variable cross-section wedge rod 4. The concrete core-filling flaps 2 are made of concrete and steel reinforcement. The concrete core-filling flaps 2 are equipped with longitudinal reinforcement 7, stirrups 8, and tie bars 9, wherein the longitudinal reinforcement 7 can be longitudinal steel bars.

[0078] Example 2:

[0079] The present invention provides a core-filling assembly for PHC pipe piles. According to the technical means of the present invention, the length and shape requirements of the variable cross-section wedge 4 in this embodiment are as follows:

[0080] As attached Figures 1-2 As shown, the variable cross-section wedge rod 4 in this invention is made of Q355 steel, and its diameter is related to the pull-out force borne by the pipe pile. The diameter of the constant cross-section section is 50mm to 80mm; the cross-sectional dimensions of the wedge section vary with the angle of the wedge slope, and the maximum cross-sectional diameter 104 of the bottom of the wedge section in the variable cross-section wedge rod 4 is 100mm to 120mm. The length of the variable cross-section wedge rod 4 varies with the length of the precast concrete flap 2. The bottom of the precast concrete flap 2 extends approximately 100mm beyond the bottom of the screw rod. The length of the precast concrete flap 2 is determined according to the pull-out bearing capacity requirements of the pile, and its range is approximately 5D to 8D, where D is the outer diameter of the PHC pipe pile. The variable cross-section wedge rod 4 is divided into a constant cross-section rod (fully threaded structure) 102 and a variable cross-section rod (smooth surface structure) 103, where the constant cross-section rod 102 is a straight rod section and the variable cross-section rod 103 is a wedge section. The length of the constant cross-section rod 102 is 3 to 4 times the length of the variable cross-section rod 103, and the length of the variable cross-section rod 103 ranges from 1D to 1.5D, where D is the outer diameter of the PHC pipe pile. (See attached...) Figure 1 As shown, the inner diameter of the PHC pipe pile is 105 mm, and the outer diameter is 106 mm. The variable cross-section wedge-shaped bar segment (smooth structure) can be either a circular cross-section or a multi-faceted structure, with the wedge angle ranging from 8° to 12°.

[0081] like Figures 3-7 As shown, in this embodiment, the number of prefabricated concrete core-filling flaps 2 is no less than 2, and can range from 3, 4, or 5. The prefabricated concrete core-filling flaps 2 can be made along the entire length and installed as a whole, or they can be divided into 3 to 5 sections along the length and made separately for installation. The wedge-shaped section of the prefabricated concrete core-filling flap 2 is one section, and the prefabricated concrete core-filling flap 2 with equal cross-sections is multiple sections, each section being approximately 1D to 2D in length, where D is the outer diameter of the PHC pipe pile.

[0082] Example 3:

[0083] Based on the same inventive concept, this invention also provides a manufacturing process for a core-filling assembly for PHC pipe piles. According to this invention, the product can be used for core-filling requirements of PHC pipe piles in various situations, and it has particular advantages in combination with prefabricated reinforced concrete foundations, as shown in the attached figure. Figure 8 As shown, the construction process of the product of this invention is as follows:

[0084] (1) Make a precast concrete core valve 2.

[0085] Precast concrete core-filled flaps are generally manufactured in precast concrete component factories. The main processes include formwork fabrication, rebar processing and tying, concrete pouring and molding, and demolding and curing. During the manufacturing process, all dimensional parameters and material strength requirements must be strictly guaranteed.

[0086] (2) Make variable cross-section wedge 4.

[0087] The variable cross-section wedge 4 is manufactured through machining, and is processed in a steel processing plant according to the design specifications. This ensures that all dimensional parameters and material strength requirements are met.

[0088] (3) Preparation for cleaning the inner wall of PHC pipe piles.

[0089] At the construction site, the inner wall of the PHC pipe pile borehole is cleaned to remove cement slurry and loose concrete, ensuring that the inner wall cross-sectional dimensions are regular and meet the shear and compressive strength requirements. The inner wall is then cleaned with high-pressure water and dried for later use.

[0090] (4) Precast assembled concrete core-filled composite components.

[0091] During construction, the prefabricated concrete core-filling valve 2, variable cross-section wedge rod 4, locking circular plate 5, and anti-loosening nut 6 are initially assembled but not tightened. After being lifted, they are sunk into the PHC pipe pile borehole. After positioning, there are gaps between the prefabricated concrete core-filling valve 2 and the inner wall of the PHC pipe pile body 1, and gaps between the three concrete core-filling valves 2 and the center of the core-filling component and the variable cross-section wedge rod 4. The variable cross-section wedge rod 4 is a variable cross-section wedge-shaped round steel rod. All gaps are filled by pressure penetration of cement-based grouting material. At the same time, a hollow jack is used to pre-apply a pull-out force to the variable cross-section wedge rod 4 in the center of the core-filling component. The wedge-shaped section of the variable cross-section wedge rod 4 forms radial or perpendicular compression to the joint surface (wedge surface) of the prefabricated concrete core-filling valve 2, thereby realizing the extrusion force between the prefabricated concrete core-filling valve 2 and the inner wall of the PHC pipe pile body 1 borehole, so as to improve the bonding strength of the concrete interface. After pre-tensioning, the fully threaded end of the variable cross-section wedge rod 4 is locked to the end plate 3 of the pipe pile using the locking circular plate 5, and the anti-loosening nut 6 is tightened. Finally, the variable cross-section wedge rod 4 provides the upward pull force for the precast assembled concrete core-filled composite component.

[0092] Compared with the prior art, the present invention also has the following beneficial effects:

[0093] (1) It can realize rapid core filling of PHC pipe pile foundation and adapt to the prefabricated construction rhythm of foundation or pile cap.

[0094] (2) The interfacial bonding strength between the core filling concrete and the inner wall of the pipe pile has been improved by artificial means, so that it can be reliably guaranteed.

[0095] (3) By making the core filler, the compressive strength quality of the core filler concrete is guaranteed.

[0096] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0097] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0098] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A core-filling assembly for PHC pipe piles, characterized in that, include: Multiple concrete core-filled flaps (2), variable cross-section wedges (4), and locking circular plates (5) were fabricated. The concrete-filled valve (2) and the variable cross-section wedge (4) are columnar structures; Multiple concrete core-filling valves (2) are set around the variable cross-section wedge rod (4) and placed together in the pipe hole at the upper end of the PHC pipe pile. The locking plate (5) fixes the variable cross-section wedge rod (4) at the top of the PHC pipe pile. The concrete-filled valve (2), the variable cross-section wedge (4), and the locking circular plate (5) are fixed by concrete pouring; The variable cross-section wedge (4) includes: a constant cross-section rod and a variable cross-section rod; The constant cross-section rod is a column structure with texture on the outside; The variable cross-section rod is a tapered straight rod with a smooth outer surface; The diameter of the uniform cross-section bar is determined based on the pull-out bearing capacity of the PHC pipe pile, the pull-out force on the uniform cross-section bar, and the profile of the uniform cross-section bar. The diameter of the variable cross-section bar is determined based on the concrete core valve (2), the pull-out bearing capacity of the PHC pipe pile, and the profile of the variable cross-section bar. The concrete core valve (2) has a fan-shaped cross section with a notch at the center of the fan shape; The number of concrete core-filling valves (2) is determined by the angle of the sector. All the concrete core-filling valves (2) enclose a circular cylinder. The notch of the concrete core-filling valve (2) forms the central hole of the circular cylinder. The variable cross-section wedge (4) is located inside the central hole. The number of concrete core-filled valves (2) shall not be less than 3; The concrete-filled valve (2) includes: A constant-section filler flap and a variable-section filler flap composed of multiple longitudinal bars (7), stirrups (8), and tie bars (9). Multiple longitudinal ribs (7) are configured as a structure with a fan-shaped cross-section; Stirrups (8) are placed around the longitudinal reinforcement (7); Tie bars (9) are distributed radially in the cross-sectional sector and connected to the longitudinal bars (7) and stirrups (8); The fan-shaped notch area of ​​the equal cross-section core-filled valve is the same; The variable cross-section core-filled valve has at least two cross-sections with different notch areas; The lengths of the variable cross-section core-filled valve and the constant cross-section core-filled valve are set according to the pull-out bearing capacity of the PHC pipe pile, respectively. The minimum cross-section of the central hole in the concrete-filled valve (2) is smaller than the maximum cross-section of the variable cross-section wedge (4); The length of the longitudinal reinforcement (7) is the same as the length of the concrete core-filling valve (2). The equal-section core-filling valve is matched with the equal-section rod, and the variable-section core-filling valve is matched with the variable-section rod. The length of the equal-section core-filling valve is less than the length of the equal-section rod, and the length of the variable-section core-filling valve is greater than the length of the variable-section rod.

2. The core-filling assembly according to claim 1, characterized in that, The bottom surface of the variable cross-section core-filled valve is located below the bottom surface of the variable cross-section rod, and there is a distance between them.

3. The core-filling assembly according to claim 2, characterized in that, The locking circular plate (5) is made of high-strength steel with holes, and its inner diameter matches the diameter of the equal cross-section rod. The outer diameter of the locking circular plate (5) is greater than the inner diameter of the PHC pipe pile.

4. A method for manufacturing a core-filling assembly for PHC pipe piles, used in the core-filling assembly as described in claim 1, characterized in that, include: The concrete core-filled valve (2) is arranged around the circumference of the variable cross-section wedge rod (4) and placed together in the pipe hole at the upper end of the PHC pipe pile; The upper end of the variable cross section wedge (4) protrudes from the top of the PHC pipe pile and is locked by the locking circular plate (5); The concrete core valve (2), the variable cross-section wedge (4), and the locking circular plate (5) are fixed by integral concrete casting.

5. The method for manufacturing the core-filling assembly according to claim 4, characterized in that, The diameter of the variable cross-section wedge (4) is designed based on the magnitude of the upward pull force borne by the PHC pipe pile and the magnitude of the upward pull force borne by the variable cross-section wedge (4), as well as the profile requirements of the variable cross-section wedge (4).

6. The method for manufacturing the core-filling assembly according to claim 5, characterized in that, The length of the circular column formed by the concrete core valve (2) is designed based on the magnitude of the pull-out force borne by the PHC pipe pile.

7. The method for manufacturing the core-filling assembly according to claim 6, characterized in that, The fabrication of the variable cross-section wedge (4) includes: The length of the variable cross-section wedge rod (4) is designed based on the length of the circular column formed by the concrete core valve (2); The profile is machined according to the diameter and length of the variable cross-section wedge (4) to obtain a variable cross-section wedge (4) including a constant cross-section bar and a variable cross-section bar; The length of the variable cross-section wedge (4) includes the lengths of the constant cross-section rod and the variable cross-section rod.

8. The method for manufacturing the core-filling assembly according to claim 7, characterized in that, The fabrication of the concrete-filled valve (2) includes: The dimensions of the concrete filling valve (2) are designed based on the dimensions of the variable cross section wedge (4), the dimensions of the PHC pipe pile, and the magnitude of the upward pull force borne by the PHC pipe pile. The external mold of the concrete filling valve (2) is selected according to the PHC pipe pile. Cut multiple longitudinal bars (7) according to the length of the concrete core valve (2); Inside the mold outside the concrete core valve (2), multiple longitudinal ribs (7) are arranged in a fan-shaped cross-section along the length of the concrete core valve (2); The longitudinal reinforcement (7) is surrounded by stirrups (8) and tied in the radial direction of the cross-section by tie bars (9); Concrete is poured into the external mold, and after curing, consolidation and demolding, concrete cored valves (2) including equal cross-section cored valves and variable cross-section cored valves are obtained. The constant cross-section core-filled valve is fitted with the constant cross-section rod, and the variable cross-section core-filled valve is fitted with the variable cross-section rod; The dimensional parameters of the concrete core-filled valve (2) include: the length of the concrete core-filled valve (2), the sector angle of the cross-section of the concrete core-filled valve (2), the sector radius, and the size of the notch at the center.

9. The method for manufacturing the core-filling assembly according to claim 8, characterized in that, The fabrication of the locking circular plate (5) includes: The dimensions of the locking circular plate (5) are designed based on the dimensions of the variable cross-section wedge (4) and the inner diameter of the PHC pipe pile and its bearing capacity and / or pull-out force requirements; The high-strength steel material is cut according to the dimensional parameters of the locking circular plate (5); After cutting, the strong steel material is machined. The inner and outer diameters of the locking circular plate (5) are machined according to the inner diameter of the PHC pipe pile and the diameter of the equal section rod to obtain the locking circular plate (5).

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