Precast pile foundation bearing platform connecting structure and construction method

Abstract

The invention relates to a precast pile foundation bearing platform connecting structure and a construction method, the precast pile foundation bearing platform connecting structure comprises a precast bearing platform, a precast pile and a connecting assembly, the precast bearing platform is provided with an up-down through post-pouring area, the connecting assembly is fixedly connected with the inner wall of the post-pouring area and the top surface of the precast pile, and concrete is poured into the post-pouring area after the connecting assembly completes connection; the connecting assembly is a steel bar connecting assembly or a steel plate connecting assembly, the steel bar connecting assembly comprises a steel bar connector and a steel bar, and the steel plate connecting assembly comprises a first steel plate and a second steel plate; the method comprises the steps that the prefabricated bearing platform and the prefabricated piles are manufactured in advance in a factory; the prefabricated pile is vertically buried in the foundation, and the prefabricated bearing platform is in butt joint with the prefabricated pile through hoisting equipment; the prefabricated bearing platform and the prefabricated pile are connected through a connecting assembly; and concrete is poured into the post-pouring area, and after the concrete is solidified, the joint part is checked and accepted. Compared with the prior art, the connecting structure has the advantages of simple structure, quick construction, reliable connection and the like.

Description

Technical Field

[0001] The invention relates to the field of construction engineering foundation structures, and in particular to a prefabricated pile foundation cap connection structure and a construction method. Background Art

[0002] With the continuous expansion of the scale of modern engineering construction, traditional pile foundation cap construction methods often face problems such as long construction period, complicated procedures, and difficult quality control. Especially in areas with complex geology and unstable foundations, the joint between the cast-in-place cap and the pile foundation often becomes the weak link of the entire structure, making it difficult to meet the requirements of high load-bearing, high safety, and seismic performance. Prefabricated components are widely used in infrastructure construction due to their advantages such as factory production, controllable quality, and fast construction speed. However, the connection problem between the prefabricated cap and the pile foundation is still a technical problem in engineering construction. How to improve construction efficiency while ensuring the strength and safety of the connection? Summary of the invention

[0003] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a prefabricated pile foundation cap connection structure and construction method with fast construction and reliable connection.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] As one aspect of the present invention, a prefabricated pile foundation cap connection structure is provided, comprising a prefabricated cap, a prefabricated pile and a connection assembly, wherein a post-casting area penetrating from top to bottom is provided on the prefabricated cap, the connection assembly is fixedly connected to the inner wall of the post-casting area and the top surface of the prefabricated pile, and concrete is poured in the post-casting area after the connection assembly is connected;

[0006] The connection assembly is a steel bar connection assembly or a steel plate connection assembly, the steel bar connection assembly includes a steel bar connector and steel bars, the steel bar connector is fixedly connected to the inner wall of the post-casting area, one end of the steel bar is fixedly connected to the top surface of the precast pile, and the other end is fixedly connected to the steel bar connector;

[0007] The steel plate connection assembly includes a first steel plate and a second steel plate. Both sides of the first steel plate are fixedly connected to the inner wall of the post-casting area. The bottom surface of the second steel plate is fixedly connected to the top surface of the precast pile. The first steel plate and the second steel plate are fixedly connected.

[0008] Furthermore, the fixed connection between the connection component and the inner wall of the post-casting area and between the connection component and the top surface of the precast pile are both embedded connections.

[0009] Furthermore, the steel bar connector is a retractable locking structure, and the steel bar connector and the steel bar are connected by thread or mechanical clamping.

[0010] Furthermore, the connection between the first steel plate and the second steel plate includes welding and connection through high-strength bolts.

[0011] Furthermore, a shear key is provided on the inner wall of the post-casting area, and a limiting device is provided at the connection between the post-casting area and the connecting assembly.

[0012] Furthermore, the material of the concrete is crack-resistant high-performance concrete.

[0013] Furthermore, the thickness of the first steel plate and the second steel plate are both greater than or equal to 20 mm.

[0014] As another aspect of the present invention, a construction method for a prefabricated pile foundation cap connection structure is provided, the method comprising the steps of:

[0015] The prefabricated cap and the prefabricated pile are prefabricated in the factory, and the steel bar connector or the first steel plate is embedded in the prefabricated cap, and the corresponding steel bar or the second steel plate is installed on the top of the prefabricated pile;

[0016] The precast piles are buried vertically in the foundation, and the precast cap is connected to the precast piles by hoisting equipment;

[0017] The prefabricated cap and the prefabricated pile are connected by a connection assembly. When the connection assembly is a steel bar connection assembly, the steel bar connector is connected to the corresponding steel bar to form a preliminary connection between the cap and the pile; when the connection assembly is a steel plate connection assembly, the first steel plate and the second steel plate are fixedly connected by high-strength bolts, and the first steel plate and the second steel plate are welded at the edges;

[0018] Pour concrete into the post-casting area of ​​the precast cap to ensure the integrity and sealing of the joint;

[0019] After the poured concrete solidifies to meet the design strength, the joints are inspected and accepted to ensure that the bearing capacity and seismic performance meet the requirements of the specifications.

[0020] Furthermore, the concrete is poured into the connection components without voids or air bubbles.

[0021] Furthermore, after the construction is completed, numerical simulation is used to verify the structural stability of the system composed of the prefabricated pile foundation cap connection structure under vertical loads, horizontal loads and seismic loads.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) The connection structure of the present invention is provided with a post-casting area on the precast foundation, and the connection between the precast foundation and the precast pile is achieved by connecting a connection component that connects the inner wall of the post-casting area and the top surface of the precast pile. The connection component includes a steel bar connection component and a steel plate connection component. After the connection components are connected, concrete is poured into the post-casting area to complete the construction. The steel bar connector and the steel plate connection design ensure the connection strength and overall stability between the foundation and the pile foundation, thereby enhancing the seismic performance. In addition, the two joint forms provide flexible choices, and the appropriate joint form can be selected according to different engineering requirements to adapt to different geological and environmental conditions, with strong adaptability.

[0024] (2) The construction method of the present invention prefabricates the prefabricated foundation and prefabricated piles in the factory, and connects the connecting components and pours the post-casting area at the construction site; through standardized post-casting construction and factory prefabrication, the difficulty and cost of on-site construction are reduced, errors are reduced, and the accuracy of quality control is improved. At the same time, the construction period is greatly shortened, the complexity of on-site construction is reduced, and the construction efficiency is improved. In addition, the concrete in the post-casting area can enhance the crack resistance and sealing of the joint, thereby improving the long-term durability and stability of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a prefabricated pile foundation cap connection structure based on a pre-buried steel bar connector;

[0026] Figure 2 A schematic diagram of a prefabricated pile foundation cap connection structure connected by steel plates and bolts;

[0027] In the figure, 1 is precast foundation, 2 is precast pile, 3 is steel bar connector, 4 is concrete, 5 is steel bar, 6 is first steel plate, 7 is high-strength bolt, 8 is second steel plate, 9 is post-casting area. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0031] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0032] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0033] Example 1

[0034] This embodiment shows a prefabricated pile foundation cap connection structure and construction method based on embedded steel bar connectors. Figure 1 As shown, the connection structure consists of a prefabricated foundation 1, a prefabricated pile 2, a steel bar connector 3, concrete 4 and steel bars 5.

[0035] The middle part of the precast cap 1 is a post-casting area 9 that runs through from top to bottom. The precast cap 1 and the precast pile 2 are firmly connected by the steel bar connector 3 embedded in the inner wall of the post-casting area 9 and the concrete 4 filled in the post-casting area 9. There are multiple steel bar connectors 3, which are used to connect with the corresponding number of steel bars 5 embedded in the top of the precast pile 2. The post-casting area 9 is used to fill the high-performance concrete 4 to ensure the overall strength and density of the joint.

[0036] In this embodiment, the steel bar connector 3 includes a retractable locking structure to adapt to different degrees of error adjustment to ensure high-precision connection.

[0037] In particular, the concrete 4 in the post-casting area 9 is made of crack-resistant high-performance concrete, and a shear key is provided in the post-casting area 9 to further improve the bending resistance and seismic resistance of the joint. At the same time, a limit device for positioning the post-casting area 9 is provided on the precast cap 1 to ensure that the connection error between the precast cap 1 and the precast pile 2 is controlled within ±5mm, thereby improving the construction accuracy.

[0038] The prefabricated cap 1 and the prefabricated pile 2 are both prefabricated in the factory before construction, and during prefabrication, the steel bar connector 3 is pre-embedded in the prefabricated cap 1, and the steel bar 5 is pre-embedded in the prefabricated pile 2. During construction, the prefabricated pile 2 is first vertically buried in the foundation, and the prefabricated cap 1 is connected to the prefabricated pile 2 by hoisting equipment, and then the steel bar connector 3 is connected to the steel bar 5.

[0039] The steel bar connector 3 and the steel bar 5 are connected by threading or mechanical clamping. After the steel bar 5 is inserted into the steel bar connector 3, it is locked by rotation or mechanically clamped to ensure a stable connection between the steel bar 5 and the steel bar connector 3. This connection method not only improves the tensile strength of the connection between the prefabricated cap 1 and the prefabricated pile 2, but also significantly improves the construction efficiency.

[0040] After the steel bar is butt-jointed, concrete 4 is poured through the post-casting area 9. The concrete 4 should be evenly poured into the steel bar connector 3 and the surrounding gaps, and ensure that there are no bubbles or gaps. After solidification, the concrete 4 forms an integral connection with the steel bar connector 3, the precast cap 1, and the precast pile 2. The design of the post-casting area 9 allows a certain positioning error, making the on-site construction more flexible;

[0041] After the construction is completed, wait for the poured concrete to solidify to the designed strength, and then check the joints to ensure that the bearing capacity and seismic performance meet the requirements of the specifications. The following items should be checked in particular:

[0042] (1) Whether the steel bar connector 3 is installed in place to ensure that the steel bar 5 is connected without looseness;

[0043] (2) Whether the concrete 4 in the post-casting area 9 is evenly filled and there are no gaps at the joints;

[0044] (3) The shear and tensile properties of the overall structure must be ensured to meet design standards.

[0045] As a preferred embodiment, after the post-casting construction is completed, the structural stability of the cap-pile system under vertical loads, horizontal loads and seismic loads can be verified through numerical simulation.

[0046] Example 2

[0047] This embodiment shows a prefabricated pile foundation cap connection structure and construction method connected by steel plates and bolts. Figure 2 As shown, the connection structure consists of a prefabricated foundation 1, a prefabricated pile 2, concrete 4, a first steel plate 6, high-strength bolts 7 and a second steel plate 8.

[0048] The difference between this embodiment and the embodiment 1 is that the precast cap 1 and the precast pile 2 are connected by the first steel plate 6, the second steel plate 8 and the high-strength bolts 7. The first steel plate 6 is embedded in the bottom of the precast cap 1, and the second steel plate 8 is embedded in the top of the precast pile 2. The first steel plate 6 and the second steel plate 8 are arranged opposite to each other, and the steel plates are fastened by the high-strength bolts 7 to ensure a firm connection between the two. The post-casting area 9 is located at the periphery of the steel plate connection, and is used to pour concrete 4 to further enhance the overall strength of the joint.

[0049] Before the construction of the prefabricated foundation 1 and the prefabricated pile 2, the first steel plate 6 and the second steel plate 8 are embedded at the bottom of the prefabricated foundation 1 and the top of the prefabricated pile 2 respectively. The size and thickness of the steel plates are determined according to the design requirements, and bolt holes are evenly opened. As a preferred embodiment, the thickness of the first steel plate 6 and the second steel plate 8 is not less than 20 mm to improve the shear resistance of the overall structure. When connecting, the high-strength bolts 7 are passed through the bolt holes of the first steel plate 6 and the second steel plate 8, and tightened with nuts. In order to improve the connection stability, the high-strength bolt 7 is connected by pre-tensioning, and a pre-tightening force is applied to the high-strength bolt 7 through the tensioning equipment to ensure that the high-strength bolt 7 does not loosen under long-term load.

[0050] In addition to the bolt connection, in order to further improve the strength and durability of the joint, welding reinforcement is used at the contact edge of the first steel plate 6 and the second steel plate 8. The welding range covers the periphery of the steel plate, and the welding process adopts gas shielded welding to ensure the strength and density of the weld. After welding, the first steel plate 6, the second steel plate 8 and the high-strength bolts 7 form an integrated structure, which enhances the shear, tensile and seismic resistance of the overall connection;

[0051] After the first steel plate 6, the second steel plate 8 and the high-strength bolts 7 are connected, high-performance concrete 4 is poured through the post-casting area 9. The concrete 4 should evenly fill the gaps around the steel plate to ensure that there are no voids or bubbles. After the concrete 4 solidifies, the first steel plate 6, the second steel plate 8, the high-strength bolts 7 and the post-casting area 9 form an integral structure, which significantly improves the bearing capacity of the joint. This post-casting structure design effectively compensates for positioning errors and adapts to complex on-site construction conditions.

[0052] After the construction is completed, the following quality checks are required:

[0053] (1) Check the tightness of the high-strength bolts 7 to ensure that the preload meets the design standards;

[0054] (2) Perform flaw detection on the welding parts of the first steel plate 6 and the second steel plate 8 to ensure that the welds are free of defects such as cracks and pores;

[0055] (3) Check whether the contact surfaces of the concrete 4 in the post-casting area 9 and the first steel plate 6 and the second steel plate 8 are tightly bonded and whether there are obvious gaps or cracks.

[0056] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A prefabricated pile foundation cap connection structure, characterized in that: The invention comprises a prefabricated foundation (1), a prefabricated pile (2) and a connection assembly, wherein the prefabricated foundation (1) is provided with a post-casting area (9) which is connected from top to bottom, the connection assembly is fixedly connected to the inner wall of the post-casting area (9) and the top surface of the prefabricated pile (2), and concrete (4) is poured into the post-casting area (9) after the connection assembly is connected. The connection assembly is a steel bar connection assembly or a steel plate connection assembly, the steel bar connection assembly comprises a steel bar connector (3) and steel bars (5), the steel bar connector (3) is fixedly connected to the inner wall of the post-casting area (9), one end of the steel bar (5) is fixedly connected to the top surface of the precast pile (2), and the other end is fixedly connected to the steel bar connector (3); The steel plate connection assembly comprises a first steel plate (6) and a second steel plate (8), the first steel plate (6) having two sides fixedly connected to the inner wall of the post-casting area (9), the bottom surface of the second steel plate (8) being fixedly connected to the top surface of the precast pile (2), and the first steel plate (6) and the second steel plate (8) being fixedly connected.

2. A prefabricated pile foundation cap connection structure according to claim 1, characterized in that: The fixed connection between the connection component and the inner wall of the post-casting area (9), and between the connection component and the top surface of the precast pile (2) are both pre-buried connections.

3. The prefabricated pile foundation cap connection structure according to claim 1, characterized in that: The steel bar connector (3) is a retractable locking structure, and the steel bar connector (3) and the steel bar (5) are connected by thread or mechanical clamping.

4. The prefabricated pile foundation cap connection structure according to claim 1, characterized in that: The connection between the first steel plate (6) and the second steel plate (8) includes welding and connection via high-strength bolts (7).

5. The prefabricated pile foundation cap connection structure according to claim 1, characterized in that: The post-casting area (9) is provided with a shear key on the inner wall, and the post-casting area (9) is provided with a limit device at the connection with the connection component.

6. The prefabricated pile foundation cap connection structure according to claim 1, characterized in that: The material of the concrete (4) is crack-resistant high-performance concrete.

7. The prefabricated pile foundation cap connection structure according to claim 1, characterized in that: The thickness of the first steel plate (6) and the second steel plate (8) are both greater than or equal to 20 mm.

8. A construction method for a prefabricated pile foundation cap connection structure according to any one of claims 1 to 7, characterized in that: The following steps are involved: The prefabricated cap (1) and the prefabricated pile (2) are respectively prefabricated in a factory, and a steel bar connector (3) or a first steel plate (6) is pre-embedded on the prefabricated cap (1), and corresponding steel bars (5) or a second steel plate (8) are installed on the top of the prefabricated pile (2); The prefabricated pile (2) is vertically buried in the foundation, and the prefabricated cap (1) is butt-jointed with the prefabricated pile (2) by means of a lifting device; The prefabricated cap (1) and the prefabricated pile (2) are connected by a connection assembly. When the connection assembly is a steel bar connection assembly, the steel bar connector (3) is connected to the corresponding steel bar (5) to form a preliminary connection between the cap and the pile. When the connection assembly is a steel plate connection assembly, the first steel plate (6) and the second steel plate (8) are fixedly connected by high-strength bolts (7), and the first steel plate (6) and the second steel plate (8) are welded at the edges. Pouring concrete (4) into the post-casting area (9) of the prefabricated cap (1) to ensure the integrity and sealing of the joint; After the post-cast concrete (4) solidifies to meet the design strength, the joints are inspected and accepted to ensure that the bearing capacity and seismic performance meet the requirements of the specifications.

9. A construction method according to claim 8, characterized in that: When the concrete (4) is poured into the connection components, it is ensured that there are no voids or bubbles.

10. A construction method according to claim 8, characterized in that: After the construction is completed, the structural stability of the system formed by the prefabricated pile foundation cap connection structure under the action of vertical load, horizontal load and seismic load is verified through numerical simulation.

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