Precast concrete variable-diameter pile foundation

Abstract

The utility model discloses a precast concrete variable-diameter pile foundation which comprises a precast concrete pile assembly, a mechanical connecting assembly and a pile tip assembly, the precast concrete pile assembly comprises a plurality of concrete pile bodies and reinforcement cages arranged in the concrete pile bodies, and the concrete pile bodies comprise large-section pile bodies and small-section pile bodies which are arranged at intervals. The large-section pile body protrudes by a certain height relative to the small-section pile body to form a protrusion. The adjacent concrete pile bodies are connected into a whole through mechanical connecting assemblies. The mechanical connecting assembly comprises an upper nut sleeve arranged at the bottom of the inner side of the upper side concrete pile body, a lower nut sleeve arranged at the top of the inner side of the lower side concrete pile body and a clamping piece connecting the upper nut sleeve and the lower nut sleeve. The upper part of the clamping piece is in threaded connection with the upper nut sleeve, and the bottom is clamped in a limiting clamping groove in the lower nut sleeve; the pile tip assembly comprises a pile tip connecting plate and a pile tip body fixed to the pile tip connecting plate. Efficient connection of upper and lower piles and pile tips can be achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of reinforced concrete prefabricated piles, in particular to a prefabricated concrete variable-diameter pile foundation. Background Art

[0002] Precast piles are mostly used in projects with relatively hard soil and high bearing capacity requirements. They are popular among many projects because of their convenient construction and high economy. With the development of building industrialization, there are higher requirements for the bending, shear and pull-out resistance of piles. This has given rise to a new type of pile foundation - prestressed concrete variable diameter pile foundation. The main function of this type of pile is to increase the friction between the soil layer and the pile by changing the cross-section of the concrete pile body, thereby improving the bearing capacity of the pile foundation while also improving the pull-out resistance, while reducing the dead weight and solving the problems of solid pile sinking and transportation difficulties.

[0003] Existing prefabricated pile foundations usually use end plate welding connections. Although this can effectively connect and greatly improve construction speed, traditional end plate welding is easily affected by human factors and weather, the welding quality is not stable enough, and there are safety hazards at the pile connection site. In addition, a large number of examples have shown that in corrosive environments, the welded pile head connection method is easily damaged and easily causes pile detachment problems. Therefore, we propose a prefabricated concrete variable diameter pile foundation with a new mechanical connection method. Utility Model Content

[0004] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and in the abstract and title of the utility model to avoid obscuring the purpose of this section, the abstract and the title of the utility model, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0005] In view of the above problems and / or the problems existing in the existing reinforced concrete precast piles, the present utility model is proposed.

[0006] Therefore, the purpose of the present invention is to provide a precast concrete variable diameter pile foundation, which can achieve the improvement of the compressive bearing capacity and the pull-out bearing capacity of the pile foundation by arranging large-section pile body segments, small-section pile body segments and protrusions at intervals. By setting a mechanical connection method, efficient connection of the upper and lower piles and the pile tips can be achieved, replacing the traditional end plate welding, making the assembly capacity stronger, the connection method simpler and easier to operate.

[0007] In order to solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0008] A precast concrete variable diameter pile foundation, comprising:

[0009] The precast concrete pile assembly includes a plurality of concrete pile bodies longitudinally connected by a mechanical connection assembly and a steel cage disposed inside the concrete pile bodies. The concrete pile bodies include large-section pile bodies and small-section pile bodies disposed at intervals. The large-section pile bodies protrude relative to the small-section pile bodies by a certain height to form a bulge.

[0010] The mechanical connection assembly includes a plurality of upper nut sleeves and lower nut sleeves of equal number and corresponding positions, and also includes a clamping member connecting the upper and lower nut sleeves into one body; the upper nut sleeves are arranged at the bottom of the upper pile body, and the lower nut sleeves are arranged at the top of the lower pile body, and one end of the clamping member is threadedly connected to the upper nut sleeves, and the other end is clamped to the lower nut sleeves;

[0011] The pile tip assembly comprises a pile tip connecting plate connected to the bottom of the lowest concrete pile body and a pile tip body fixed at the middle of the lower end of the pile tip connecting plate.

[0012] As a preferred technical solution, each concrete pile body includes a pile head and a pile bottom with a large cross-section. The large and small cross-section sections between the pile head and the pile bottom are spaced apart to ensure that the pressure on the pile end is the greatest.

[0013] As an optimal technical solution, the steel cage includes main bars and stirrups; a plurality of main bars made of prestressed steel bars are evenly arranged around the pile body, the stirrups are arranged perpendicular to the main bars, and the stirrup arrangement density at both ends of the pile body is greater than that in the middle area.

[0014] As a preferred technical solution, the main reinforcement of the steel cage is connected between the upper nut sleeve and the lower nut sleeve of the same section of the pile body.

[0015] As a preferred technical solution, the top end of the upper nut sleeve and the bottom end of the lower nut sleeve are both provided with openings for connecting to the main reinforcement, and the openings are clamped with the ends of the main reinforcement through a limiting structure.

[0016] As a preferred technical solution, the clamping part includes a threaded connector, an elastic rod and a barb; the threaded connector is a cylindrical connector with an external thread, and an elastic rod is provided at the bottom of the connector; the elastic rod is a cylindrical hollow annular column as a whole; a plurality of vertical openings are evenly and symmetrically arranged along the circumference of the elastic rod, and a barb is provided between every two vertical openings, and the barb is provided on the side away from the center of the elastic rod and is integrally formed with the bottom of the elastic rod; the entire elastic rod and the barb can be retracted toward the center of the elastic rod under the action of external force.

[0017] As a preferred technical solution, the upper nut sleeve is provided with an internal thread to connect to the threaded connector;

[0018] As an optimal technical solution, a convex-shaped socket that is narrow at the top and wide at the bottom is provided inside the lower nut sleeve; the upper half of the socket is used to accommodate the elastic plug rod, and the inner diameter of the lower half is larger than that of the upper half to form a slot for clamping the barb.

[0019] As a preferred technical solution, the pile tip body adopts a cross-shaped pile tip or a conical pile tip.

[0020] As an optimal technical solution, the pile tip connecting plate is provided with a threaded hole corresponding to the upper nut sleeve at the bottom of the lowest section of the pile body, and the two ends of the connecting screw are threadedly connected to the pile tip and the upper nut sleeve of the lowest section of the concrete pile body through the threaded hole respectively.

[0021] Compared with the existing technology, the beneficial effects of the present invention are as follows: this precast concrete variable diameter pile foundation can improve the compressive bearing capacity and pull-out bearing capacity of the pile foundation by arranging large-section pile body segments, small-section pile body segments and protrusions at intervals, and realizes efficient connection of the upper and lower pile bodies and pile tips by setting mechanical connection components, replacing traditional end plate welding, making the assembly capacity stronger, the connection method more simple and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below in conjunction with the accompanying drawings and detailed embodiments. 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 inventive labor. Among them:

[0023] Figure 1 This is a schematic diagram of the three-dimensional structure of the precast concrete variable diameter pile foundation of the utility model;

[0024] Figure 2 This is a schematic diagram of the connection between the upper and lower pile bodies of the precast concrete variable diameter pile foundation of the present utility model;

[0025] Figure 3 This is a schematic diagram of the mechanical connection assembly structure of the present utility model;

[0026] Figure 4 This is a schematic diagram of the connection structure between the variable diameter pile foundation tip assembly and the precast concrete pile assembly of the utility model.

[0027] In the figure: 100, concrete precast pile assembly; 101, protrusion; 102, main reinforcement; 110, large-section pile body; 120, small-section pile body; 200, mechanical connection assembly; 210, upper nut sleeve; 220, lower nut sleeve; 230, slot; 240, limiting structure; 250, clamping part; 260, elastic plug rod; 300, pile tip assembly; 310, pile tip connecting plate; 320, bolt; 330, pile tip body. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0029] Next, the present invention is described in detail with reference to schematic diagrams. For ease of illustration, cross-sectional views of device structures may be partially enlarged and not to scale when describing the embodiments of the present invention. Furthermore, the schematic diagrams are merely illustrative and should not limit the scope of protection of the present invention. Furthermore, in actual production, three-dimensional dimensions, including length, width, and depth, should be included.

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] The utility model provides a precast concrete variable diameter pile foundation, which can improve the compressive bearing capacity and pull-out bearing capacity of the pile foundation by arranging large-section pile body segments, small-section pile body segments and protrusions at intervals. By arranging mechanical connections, efficient connection of upper and lower piles and pile tips is achieved, replacing traditional end plate welding, making the assembly capacity stronger, the connection method simpler and easier to operate.

[0032] The variable diameter pile foundation of this utility model can be configured as a solid or hollow precast concrete pile foundation with circular, square, polygonal, or other shapes according to practical needs. This case study focuses on the special-shaped square pile, but the shape of the practical pile can be varied according to the specific project situation and is not limited to the description of square piles.

[0033] See also Figures 1 to 4 The utility model discloses a precast concrete variable diameter pile foundation, which includes a precast concrete pile assembly 100, a mechanical connection assembly 200 and a pile tip assembly 300.

[0034] The precast concrete pile assembly 100 includes a plurality of concrete pile bodies longitudinally connected by the mechanical connection assembly 200 and a steel cage arranged inside the concrete pile body. The concrete pile body includes a large-section pile body 110 and a small-section pile body 120 arranged at intervals. The large-section pile body 110 protrudes a certain height relative to the small-section pile body 120 to form a protrusion 101. The plurality of concrete pile bodies form a variable-diameter pile foundation along the longitudinal direction.

[0035] Each concrete pile body comprises a pile head and a pile bottom with a large cross-section. The large and small cross-section sections between the pile head and the pile bottom are arranged at intervals to ensure that the pressure borne by the pile end is the greatest.

[0036] Because concrete has high compressive strength but low tensile strength, the steel cage primarily constrains the concrete pile, enabling it to withstand a certain amount of axial tension. The cage comprises main bars 102 and stirrups. Multiple main bars, made of prestressed steel, are evenly distributed around the pile. The upper and lower ends of the main bars are connected to mechanical connection assemblies 200 within the pile. The stirrups are arranged perpendicular to the main bars, and the density of the stirrups at the ends of the pile is greater than in the middle.

[0037] The mechanical connection assembly 200 includes a plurality of upper nut sleeves 210 and lower nut sleeves 220 of equal quantity and corresponding positions, and also includes a clamping member that connects the upper and lower nut sleeves into one; the upper nut sleeve is arranged at the bottom of the upper section of the pile body, and the lower nut sleeve is arranged at the top of the lower section of the pile body; the number of nut sleeves is determined according to the pile foundation pipe diameter and the number of steel bars.

[0038] The clamping part includes a threaded connector 250, an elastic rod 260 and a hook 270; the threaded connector is a cylindrical connector with an external thread, and an elastic rod 260 is provided at the bottom; the elastic rod is a cylindrical hollow annular column as a whole; four vertical openings are evenly and symmetrically arranged along the circumference of the elastic rod 260, and a hook 270 is provided between each two vertical openings. The hook 270 is provided on the side away from the center of the elastic rod and is integrally formed with the bottom of the elastic rod 260; the entire elastic rod 260 and the hook 270 can be retracted toward the center of the elastic rod 260 under the action of external force.

[0039] The outer diameter of the lower nut sleeve is greater than the outer diameter of the upper nut sleeve.

[0040] The upper nut sleeve 210 is provided with an internal thread for connecting to the threaded connector 250 .

[0041] The outer wall of the lower nut sleeve 220 is a smooth inscribed decagonal cylinder, and a convex-shaped smooth inner wall socket with a narrow upper part and a wide lower part is provided inside; the upper half of the socket is used to accommodate the elastic plug rod 260, and the lower half has a thinner wall thickness and a larger inner diameter than the upper half, forming a slot 230 for clamping the hook.

[0042] Preferably, the outer wall of the elastic rod 260 is inclined toward the center of the elastic rod from the side of the threaded connector 250 to the side of the barb 270. Preferably, the barb 270 is smoothly connected to the elastic rod 260, and the corners are provided with rounded corners for easy insertion. More preferably, the upper portion of the barb is a right-angle section so as to fit with the top and side walls of the slot, and the lower portion of the barb is an inclined surface so as to be inserted into the socket during installation. In a natural state, the outer wall size of the barb is larger than the top opening of the socket of the lower nut sleeve. During installation, the elastic rod is compressed inwardly. After entering the socket of the lower nut sleeve, as the inner diameter of the socket increases, the barb expands outward and locks with the slot.

[0043] Preferably, a plurality of upper nut sleeves are embedded in the bottom of the upper pile body, and an equal number of lower nut sleeves are embedded in the top of the lower pile body. The number of nut sleeves is determined according to the pile foundation pipe diameter and the number of steel bars.

[0044] Preferably, a steel cage is embedded in both the upper and lower pile sections, and the main bars 102 of the steel cage are connected between the upper nut sleeve and the lower nut sleeve of the same pile section.

[0045] Preferably, the two ends of the same main reinforcement are respectively connected to the upper nut sleeve 210 and the lower nut sleeve 220 inside the pile body. The top end of the upper nut sleeve is opened with a hole for connecting to the bottom end of the main reinforcement of the upper pile body; similarly, the bottom end of the lower nut sleeve is opened with a hole for connecting to the top end of the main reinforcement of the lower pile body. The upper and lower nut sleeves are connected by an elastic plug and a limit slot to achieve a mechanical connection between the upper and lower pile bodies. The pile head plane where the upper and lower pile bodies meet is coated with structural adhesive, which can be squeezed out when the upper and lower pile bodies are connected, thereby achieving a stable connection between the two pile bodies.

[0046] Preferably, in this embodiment, the inner sides of the upper and lower nut sleeves are clamped with the ends of the main reinforcement through the limiting structure 240, ensuring the stable connection between the upper nut sleeve 210 and the lower nut sleeve 220, and further ensuring the stable connection between the two concrete pile bodies.

[0047] The main reinforcement 102 can be made of threaded steel, PC steel rod or steel strand. The main reinforcement 102 made of various materials enhances the practicality of the device, allowing the operator to select the appropriate material according to the actual use situation:

[0048] When the main reinforcement 102 is made of threaded steel, a threaded through hole matching the threaded end is provided in the upper nut sleeve 210 and the lower nut sleeve 220, and the thread of the main reinforcement is screwed into the threaded through hole. The limiting structure is an enlarged portion provided at the threaded end, and the diameter of the enlarged portion is larger than the diameter of the threaded through hole, so that the main reinforcement can be limited in the nut sleeve; when the main reinforcement 102 is a PC steel bar, the limiting structure includes a through hole provided at the bottom of the upper nut sleeve 210 and the lower nut sleeve 220 and a flange provided on the inner side of the through hole, and the internal space of the flange is The space is funnel-shaped and cooperates with the steel rod; when the main reinforcement 102 is a steel strand, the limiting structure includes a conical hole provided at the bottom of the upper nut sleeve 210 and the lower nut sleeve 220 and with the large mouth facing inward, and a steel strand anchor head with a conical outer surface is provided in the conical hole. The outer surface of the steel strand anchor head cooperates with the conical hole, and the steel strand anchor head is limited in the conical hole, and a steel wire retaining spring is provided on the outside of the steel strand anchor head. The steel strand anchor head is sleeved and fixed on the end of the steel strand to realize the connection between the steel strand and the upper nut sleeve 210 and the lower nut sleeve 220.

[0049] The pile tip assembly 300 includes a pile tip connection plate 310 connected to the bottom of the lowest concrete pile body and a pile tip body 330 fixed to the middle of the lower end of the pile tip connection plate. The pile tip connection plate is provided with a threaded hole 320 corresponding to the upper nut sleeve at the bottom of the lowest pile body. The two ends of the connecting screw are respectively threadedly connected to the pile tip and the upper nut sleeve of the lowest concrete pile body through the threaded hole.

[0050] Preferably, in this embodiment, the pile tip body 330 can adopt a cross-shaped pile tip or a conical pile tip. The pile tip body 330 with a cross-shaped pile tip or a conical pile tip allows the operator to select a suitable pile tip according to actual usage, further enhancing the practicality of the device.

[0051] Combine Figures 1 to 4 The precast concrete variable diameter pile foundation of this embodiment is specifically used as follows: the large-section pile body 110, the small-section pile body 120 and the protrusion 101 arranged at intervals can improve the compressive bearing capacity and the pull-out bearing capacity of the pile foundation; when the two concrete pile bodies need to be connected, the clamping piece is first installed in the upper nut sleeve 210, and then the structural glue is applied to the pile head of the lower concrete pile body. Finally, the elastic plug rod 260 is inserted into the lower nut sleeve 220 of the lower concrete pile body. The elastic plug rod 260 is squeezed into the lower nut sleeve 220 under the push of external force until it is stuck in the slot 230. A sound of the elastic plug rod 260 being stuck is heard. At this time, the elastic plug rod 260 completely enters the lower nut sleeve 220 and is squeezed out along with the applied structural glue, thereby achieving the fixation of the upper nut sleeve 210 and the lower nut sleeve 220, and then achieving the connection of the two concrete pile bodies.

[0052] While the present invention has been described above with reference to specific embodiments, various modifications may be made and equivalent components may be substituted without departing from the scope of the present invention. In particular, as long as no structural conflicts exist, the various features of the embodiments disclosed herein may be combined with one another in any manner, and the omission of an exhaustive description of these combinations in this specification is solely for the sake of space and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A precast concrete variable diameter pile foundation, characterized in that: include: The precast concrete pile assembly includes a plurality of concrete pile bodies longitudinally connected by a mechanical connection assembly and a steel cage disposed inside the concrete pile bodies. The concrete pile bodies include large-section pile bodies and small-section pile bodies disposed at intervals. The large-section pile bodies protrude relative to the small-section pile bodies by a certain height to form a bulge. The mechanical connection assembly includes a plurality of upper nut sleeves and lower nut sleeves of equal number and corresponding positions, and also includes a clamping member connecting the upper and lower nut sleeves into one body; the upper nut sleeves are arranged at the bottom of the upper pile body, and the lower nut sleeves are arranged at the top of the lower pile body, and one end of the clamping member is threadedly connected to the upper nut sleeves, and the other end is clamped to the lower nut sleeves; The pile tip assembly comprises a pile tip connecting plate connected to the bottom of the lowest concrete pile body and a pile tip body fixed at the middle of the lower end of the pile tip connecting plate.

2. The precast concrete variable diameter pile foundation according to claim 1, characterized in that: Each concrete pile body comprises a pile head and a pile bottom with a large cross-section. The large and small cross-section sections between the pile head and the pile bottom are arranged at intervals to ensure that the pressure borne by the pile end is the greatest.

3. The precast concrete variable diameter pile foundation according to claim 1, characterized in that: The steel cage includes main bars and stirrups; a plurality of main bars made of prestressed steel bars are evenly arranged around the pile body, the stirrups are arranged perpendicular to the main bars, and the stirrup arrangement density at both ends of the pile body is greater than that in the middle area.

4. The precast concrete variable diameter pile foundation according to claim 3, characterized in that: The main reinforcement of the steel cage is connected between the upper nut sleeve and the lower nut sleeve of the same section of the pile body.

5. The precast concrete variable diameter pile foundation according to claim 4, characterized in that: The top end of the upper nut sleeve and the bottom end of the lower nut sleeve are both provided with openings for connecting the main reinforcement, and the openings are clamped with the ends of the main reinforcement through a limiting structure.

6. The precast concrete variable diameter pile foundation according to claim 1, characterized in that: The clamping part includes a threaded connector, an elastic rod and a barb; the threaded connector is a cylindrical connector with an external thread, and an elastic rod is provided at the bottom of the threaded connector; the elastic rod is a hollow cylindrical ring-shaped column as a whole; a plurality of vertical openings are evenly and symmetrically arranged along the circumference of the elastic rod, and a barb is provided between every two vertical openings, and the barb is provided on the side away from the center of the elastic rod and is integrally formed with the bottom of the elastic rod; the entire elastic rod and the barb can be retracted toward the center of the elastic rod under the action of an external force.

7. The precast concrete variable diameter pile foundation according to claim 6, characterized in that: The upper nut sleeve is provided with an internal thread for connecting to the threaded connector.

8. The precast concrete variable diameter pile foundation according to claim 6, characterized in that: The lower nut sleeve is provided with a convex-shaped socket which is narrow at the top and wide at the bottom. The upper part of the socket is used to accommodate the elastic plug rod, and the inner diameter of the lower part is larger than that of the upper part to form a slot for clamping the barb.

9. The precast concrete variable diameter pile foundation according to claim 1, characterized in that: The pile tip body adopts a cross-shaped pile tip or a cone-shaped pile tip.

10. The precast concrete variable diameter pile foundation according to claim 9, characterized in that: The pile tip connecting plate is provided with a threaded hole corresponding to the upper nut sleeve at the bottom of the lowest pile body, and the two ends of the connecting screw are threadedly connected to the pile tip and the upper nut sleeve of the lowest concrete pile body through the threaded holes respectively.

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