Precast pile
By adopting the cage rib skeleton design and the circumferential deflection of the main rib in the precast concrete pipe pile, the problem of insufficient bearing capacity of the precast concrete pipe pile in the prior art is solved, and higher structural stability and pressure resistance are achieved.
Patent Information
- Application Number
- CN202510436894.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2025-06-06
AI Technical Summary
There is still room for improvement in the bearing capacity of existing precast concrete pipe piles, especially under soft soil foundation conditions, the traditional straight main rib design may lead to prestress loss and stress concentration problems.
The cage rib skeleton design is adopted, in which the main ribs are arranged in a circumferential direction and are deflected along the circumferential deflection angle α in the length direction of the concrete pile body. The center angle θ of α is greater than or equal to 0.5° and less than or equal to 1/2, and the circumferential deflection direction of the main ribs is the same.
The axial deflection of the main rib reduces prestress loss, enhances the overall stability and pressure resistance of the structure, reduces the risk of fracture at the end of the main rib, and improves the safety and durability of the structure.
Smart Images
Figure CN120099942A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of building materials and relates to a prefabricated pile. Background Art
[0002] Precast concrete pipe piles have been widely used in various construction engineering scenarios due to their excellent mechanical properties and ease of construction. In the foundation engineering of high-rise residential buildings, commercial buildings and super high-rise buildings, concrete pipe piles have become an ideal choice of foundation materials due to their high bearing capacity and good stability. Especially under soft soil conditions, the use of prestressed high-strength concrete pipe piles (PHC piles) can effectively reduce foundation settlement and ensure the safety and stability of the building.
[0003] At present, precast concrete pipe piles on the market are formed by pouring concrete with a main reinforcement array composed of main reinforcements. The projection angle of the main reinforcement at both ends is usually 0°. According to conventional engineering knowledge, keeping the main reinforcement straight helps to maximize the bearing capacity of precast concrete pipe piles, because the straight line shape can transfer loads more effectively and reduce stress concentration points, thereby ensuring the overall stability and strength of the structure.
[0004] However, with the development of engineering technology and in-depth research on material properties, people have found that even under this so-called "optimal design", the bearing capacity of precast concrete piles still has room for significant improvement. Summary of the invention
[0005] The purpose of the present invention is to solve the above problems in the prior art and to provide a prefabricated pile, comprising:
[0006] The cage reinforcement skeleton is composed of a main reinforcement array formed by a plurality of main reinforcements arranged in a circumferential direction and stirrups arranged around the main reinforcement array;
[0007] A concrete pile body, which is cast on the cage reinforcement skeleton;
[0008] In the projection along the length direction of the concrete pile body, one end of the main reinforcement is deflected at an angle α relative to the other end of the main reinforcement along the circumferential direction of the concrete pile body.
[0009] In the above-mentioned precast pile, the central angle between two adjacent main reinforcements is θ, and the deflection angle α is smaller than the central angle θ.
[0010] In the above-mentioned precast pile, the deflection angle α is greater than or equal to 0.5°, and the circumferential deflection directions of the main reinforcements are the same.
[0011] In the above-mentioned precast pile, the deflection angle α is less than or equal to 1 / 2 of the center angle θ, and the circumferential deflection angles of the main reinforcements are the same.
[0012] In the above-mentioned precast pile, the deflection angle α is in the range of 0° to 3°, and the main reinforcement is uniformly deflected in the circumferential direction along the length direction of the concrete pile body.
[0013] In the above-mentioned precast pile, it also includes end plates, two of which are respectively arranged at the two ends of the concrete pile body, and the end plates are provided with end holes, and the ends of the main reinforcement are installed in the end holes.
[0014] In the above-mentioned prefabricated pile, the end hole includes an anchor hole, a reinforcement hole and a reinforcement groove, and the anchor hole and the reinforcement hole are connected through the reinforcement groove.
[0015] In the above-mentioned precast pile, the concrete pile body is provided with a thick pile segment and a thin pile segment, and the thick pile segment and the thin pile segment are alternately arranged in sequence along the length direction of the concrete pile body. The concrete pile body is also provided with a frustum-shaped pile segment, and the thick pile segment and the thin pile segment are transitionally connected by the frustum-shaped pile segment.
[0016] In the above-mentioned precast pile, sleeves are pre-buried at both ends of the concrete pile body, and the ends of each main reinforcement are respectively connected and fixed to a corresponding one of the sleeves.
[0017] The above-mentioned prefabricated pile further includes a hooping, wherein two hoopings are respectively sleeved on the sleeves at both ends of the concrete pile body.
[0018] Compared with the prior art, the present invention has the following beneficial effects:
[0019] 1. Controlling the axial deflection of the main reinforcement helps reduce prestress loss. Prestressing technology offsets the tensile stress that may be caused by external loads by pre-applying pressure to the concrete, thereby increasing the service life and bearing capacity of the structure.
[0020] 2. Limit the deflection angle of the main reinforcement according to the number of main reinforcements. If the axial deflection of the main reinforcement is too large, it will not only lead to the loss of prestress, but also may cause the risk of fracture at the end of the main reinforcement, which will seriously affect the safety of the structure.
[0021] 3. Setting the deflection angle α to at least 0.5° can ensure that each main reinforcement has a minimum deflection angle, which not only helps to enhance the overall stability of the structure, but also effectively disperses the impact of external forces on a single main reinforcement, making the entire structure more solid and durable.
[0022] 4. The alternating thick and thin design is particularly important in precast pile projects. It not only helps to give full play to the lateral friction and end bearing capacity of the precast piles, thereby significantly improving the overall mechanical bearing performance of the pile body, but also effectively optimizes the stability and durability of the entire structure. A frustum-shaped transition pile section is added between the thick pile section and the thin pile section to eliminate or reduce the stress concentration problem that may occur inside the pile body and ensure the safety and reliability of the pile body in long-term use.
[0023] 5. By using sleeves to connect two concrete piles, various challenges brought about by length limitations during transportation of concrete piles have been greatly overcome. After adopting the sleeve connection method, the length of a single concrete pile is no longer a fixed constraint factor. This method not only ensures the integrity and stability of the pile structure, but also significantly improves the construction flexibility and adaptability. Whether in narrow urban spaces or in remote areas with inconvenient transportation, the appropriate pile length can be customized according to actual needs without worrying about the limitations caused by transportation problems. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a structural schematic diagram of the present invention.
[0025] Figure 2 It is a schematic diagram of the cage reinforcement skeleton of the present invention.
[0026] Figure 3 Schematic diagram of the end plate of the present invention.
[0027] Figure 4 Schematic diagram of the end hole of the present invention.
[0028] Figure 5 It is a schematic diagram of a ferrule of the present invention.
[0029] In the figure:
[0030] 1. Cage reinforcement skeleton; 11. Main reinforcement; 12. Hoop reinforcement; 2. Concrete pile body; 21. Thick pile section; 22. Thin pile section; 23. Cone-shaped pile section; 3. End plate; 31. End hole; 311. Anchor hole; 312. Rebar hole; 313. Rebar groove; 4. Hoop. DETAILED DESCRIPTION
[0031] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.
[0032] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0033] In addition, in the present invention, descriptions such as "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, "multiple" means at least two, for example two, three, etc., unless otherwise clearly and specifically defined.
[0034] In the present invention, unless otherwise clearly stipulated and limited, the terms "connection", "fixed" and the like should be understood in a broad sense. For example, "fixed" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to specific circumstances.
[0035] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.
[0036] The specific embodiments described in this article are merely examples of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner, but they will not deviate from the present invention or exceed the scope defined by the attached claims.
[0037] like Figure 1-Figure 5 As shown, a prefabricated pile includes: a cage reinforcement frame 1 and a concrete pile body 2.
[0038] The cage reinforcement skeleton 1 is composed of a main reinforcement array 11 formed by a plurality of main reinforcements 11 arranged and distributed in a circumferential direction and stirrups 12 arranged around the main reinforcement array 11 .
[0039] The concrete pile body 2 is cast on the cage reinforcement frame 1, and the concrete pile body 2 is provided with an inner wall and an outer wall.
[0040] In the projection of the length direction of the concrete pile body 2 , one end of the main reinforcement 11 is deflected by an angle α along the circumferential direction of the concrete pile body 2 relative to the other end of the main reinforcement 11 .
[0041] Specifically, before pouring, the stirrups 12 can fix several main bars 11 arranged in a circumferential direction to prevent the main bars 11 from being unevenly distributed on the concrete pile body 2 due to position deviation of the main bars 11 during the pouring of the concrete pile body 2, thereby causing stress concentration.
[0042] In this embodiment, controlling the axial deflection of the main reinforcement 11 helps to reduce prestress loss. The prestressing technology offsets the tensile stress that may be caused by external loads by applying pressure to concrete in advance, thereby increasing the service life and bearing capacity of the structure.
[0043] like Figure 1-Figure 5 As shown, based on the above implementation, the central angle between two adjacent main ribs 11 is θ, and the deflection angle α is smaller than the central angle θ.
[0044] In this embodiment, the deflection angle of the main reinforcement 11 is limited according to the number of the main reinforcements 11. If the axial deflection of the main reinforcement 11 is too large, it will not only cause the loss of prestress, but also may cause the risk of fracture of the end of the main reinforcement 11, which will seriously affect the safety of the structure.
[0045] like Figure 1-Figure 5 As shown, based on the above implementation, the deflection angle α is greater than or equal to 0.5°, and the circumferential deflection directions of the main ribs 11 are the same.
[0046] In this embodiment, the deflection angle α is set to at least 0.5°, which can ensure that each main reinforcement 11 has a minimum deflection angle, which not only helps to enhance the overall stability of the structure, but also effectively disperses the impact of external forces on a single main reinforcement 11, making the entire structure more solid and durable.
[0047] like Figure 1-Figure 5 As shown, based on the above implementation, the deflection angle α is less than or equal to 1 / 2 of the central angle θ, and the circumferential deflection angles of the main ribs 11 are the same.
[0048] In this embodiment, it is crucial to reasonably set the layout and angle of the main reinforcement 11 to ensure the safety and durability of the structure. The deflection angle α is less than or equal to 1 / 2 of the central angle θ. On the basis of ensuring that the main reinforcement 11 has a deflection angle α, the number of the main reinforcement 11 can also meet the standard requirements. By limiting the deflection angle of the main reinforcement 11 and ensuring that the main reinforcements 11 are kept at a uniform spacing, the bearing capacity of the precast pile can be effectively enhanced.
[0049] like Figure 1-Figure 5 As shown, based on the above embodiment, the deflection angle α is in the range of 0° to 3°, and the main reinforcement 11 is uniformly deflected along the circumferential direction in the length direction of the concrete pile body 2 .
[0050] In this embodiment, the deflection angle α is set between 0° and 3°. The precast pile has sufficient bearing capacity without causing excessive deflection to cause loss of prestress or breakage of the main reinforcement 11. By reasonably selecting the deflection angle, it is possible to ensure that the bond strength between the main reinforcement 11 and the concrete reaches the optimal state, thereby enhancing the bearing capacity and durability of the entire structure.
[0051] like Figure 1-Figure 5 As shown, based on the above embodiment, it further includes end plates 3, two end plates 3 are respectively arranged at the two ends of the concrete pile body 2, and the end plates 3 are provided with end holes 31, and the ends of the main reinforcement 11 are installed in the end holes 31.
[0052] In this embodiment, the end of the main reinforcement 11 is upset and then passed through the end hole 31 to be connected to the end plate 3. The end plate 3 enhances the integrity and stability of the pile by connecting with the main reinforcement 11. This connection method ensures good cooperative working performance between the various parts of the pile body and improves the ability of the pile body to resist external loads. The end plate 3 helps to distribute the externally applied load more evenly on the cross-section of the pile body, thereby reducing local stress concentration. This not only extends the service life of the pile, but also reduces the risk of damage caused by uneven stress.
[0053] like Figure 1-Figure 5 As shown, based on the above embodiment, the end hole 31 includes an anchor hole 311 , a rib hole 312 and a rib groove 313 , and the anchor hole 311 and the rib hole 312 are connected through the rib groove 313 .
[0054] Specifically, the outer diameter of the end of the main reinforcement 11 after being upset is smaller than the aperture of the reinforcement hole 312 but larger than the minimum aperture of the step hole of the anchor hole 311, and the width of the reinforcement groove 313 is also smaller than the outer diameter of the end of the main reinforcement 11 after being upset. In this way, the end of the main reinforcement 11 first passes through the reinforcement hole 312 after being upset, and then slides into the anchor hole 311 through the reinforcement groove 313. The step surface of the end of the main reinforcement 11 after being upset is abutted and fixed with the step surface of the step hole of the anchor hole 311.
[0055] In this embodiment, through the anchor hole 311, the reinforcement hole 312 and the reinforcement groove 313, the end of the main reinforcement 11 can be upset in advance before the end plate 3 is installed, which simplifies the complex installation process and improves the construction efficiency.
[0056] The finite element simulation analysis of AB type hollow precast piles with outer diameters of 400mm, 500mm, 600mm and 800mm was carried out using FLAC 3D 6.0 software. The pile body was defined as a linear elastic material, the number of grids was 3872, and the linear hexahedron, among which the material mechanical parameters of the standard value of concrete cube compressive strength fcu, the design value of axial compressive strength fc, and the design value of axial tensile strength ft were selected as shown in Table 1:
[0057] Table 1 Mechanical parameters of pile concrete
[0058]
[0059] Among them, the elastic modulus E, yield strength fy, ultimate strength fu and maximum elongation Agt of the main reinforcement are shown in Table 2, and the experimental data are shown in Table 3:
[0060] Table 2 Mechanical parameter values of main reinforcement (prestressed steel bar)
[0061]
[0062] Table 3 Ultimate bending bearing capacity simulation experimental values
[0063]
[0064]
[0065] From the data in Table 3, it can be seen that for hollow pipe piles with different outer diameters, a circumferential deflection angle α of 2° relative to 0° (i.e., the anchor holes at both ends of the pile body are aligned along the length direction Z of the concrete pile body) can improve the ultimate bending bearing capacity of the pile body.
[0066] like Figure 1-Figure 5 As shown, on the basis of the above embodiment, the concrete pile body 2 is provided with a thick pile segment 21 and a thin pile segment 22, and the thick pile segment 21 and the thin pile segment 22 are alternately arranged in sequence along the length direction of the concrete pile body 2. The concrete pile body 2 is also provided with a frustum-shaped pile segment 23, and the thick pile segment 21 and the thin pile segment 22 are transitionally connected by the frustum-shaped pile segment 23.
[0067] In this embodiment, the alternating thick and thin design is particularly important in precast pile engineering. It not only helps to give full play to the lateral friction and end bearing capacity of the precast pile, thereby significantly improving the overall mechanical bearing performance of the pile body, but also can effectively optimize the stability and durability of the entire structure. A frustum-shaped transition pile segment is added between the thick pile segment 21 and the thin pile segment 22 to eliminate or reduce the stress concentration problem that may occur inside the pile body, and ensure the safety and reliability of the pile body in long-term use.
[0068] like Figure 1-Figure 5 As shown, on the basis of the above embodiment, sleeves (not shown) are pre-buried at both ends of the concrete pile body 2, and the ends of each main reinforcement 11 are respectively connected and fixed to a corresponding sleeve.
[0069] Specifically, due to transportation conditions, the length of the concrete pile body 2 is usually between 7 and 15 meters, but the concrete pile body 2 used in the pile foundation is usually between 40 and 60 meters. This requires the concrete pile body 2 to be formed and manufactured in sections in the factory and then extended at the construction site. Figure 1 The ends of the main reinforcement 11 are respectively connected and fixed with a corresponding sleeve, and the sleeve has a cavity exposed at the end face of the pile. During construction, the lower sleeve of the upper concrete pile body 2 is connected and fixed with the upper sleeve of the lower concrete pile body 2.
[0070] In this embodiment, by using a sleeve to connect two concrete pile bodies 2, various challenges caused by length limitations during transportation of concrete piles are greatly overcome. After adopting the sleeve connection method, the length of a single concrete pile body 2 is no longer a fixed constraint factor. This method not only ensures the integrity and stability of the pile structure, but also significantly improves the construction flexibility and adaptability. Whether in a narrow urban space or in a remote area with inconvenient transportation, the appropriate pile length can be customized according to actual needs without worrying about the limitations caused by transportation problems.
[0071] like Figure 1-Figure 5 As shown, on the basis of the above embodiment, it further includes a sleeve 4, and two sleeves 4 are respectively sleeved on the sleeves at both ends of the concrete pile body 2.
[0072] In this embodiment, the hoop 4 can significantly improve the shear resistance of the concrete pile body 2 when subjected to lateral forces, especially when the concrete pile body 2 is subjected to complex loads such as lateral earth pressure and earthquake effects. The hoop 4 effectively prevents shear failure of the concrete pile body 2 by providing additional constraints.
Claims
1. A prefabricated pile, characterized in that: include: The cage reinforcement skeleton is composed of a main reinforcement array formed by a plurality of main reinforcements arranged in a circumferential direction and stirrups arranged around the main reinforcement array; A concrete pile body, which is cast on the cage reinforcement skeleton; In the projection along the length direction of the concrete pile body, one end of the main reinforcement is deflected at an angle α relative to the other end of the main reinforcement along the circumferential direction of the concrete pile body.
2. A prefabricated pile according to claim 1, characterized in that: The center angle between two adjacent main ribs is θ, and the deflection angle α is smaller than the center angle θ.
3. A prefabricated pile as claimed in claim 2, characterized in that: The deflection angle α is greater than or equal to 0.5°, and the circumferential deflection directions of the main ribs are the same.
4. A prefabricated pile as claimed in claim 3, characterized in that: The deflection angle α is less than or equal to 1 / 2 of the central angle θ, and the circumferential deflection angles of the main ribs are the same.
5. A prefabricated pile as claimed in claim 4, characterized in that: The deflection angle α is in the range of 0° to 3°, and the main reinforcement is uniformly deflected in the circumferential direction along the length direction of the concrete pile body.
6. A prefabricated pile according to claim 1, characterized in that: It also includes end plates, wherein two end plates are respectively arranged at the two ends of the concrete pile body, and the end plates are provided with end holes, and the ends of the main reinforcement are installed in the end holes.
7. A prefabricated pile as claimed in claim 6, characterized in that: The end hole comprises an anchor hole, a reinforcement hole and a reinforcement groove, and the anchor hole and the reinforcement hole are connected through the reinforcement groove.
8. A prefabricated pile as claimed in claim 1, characterized in that: The concrete pile body is provided with a thick pile segment and a thin pile segment, and the thick pile segment and the thin pile segment are alternately arranged in sequence along the length direction of the concrete pile body. The concrete pile body is also provided with a frustum-shaped pile segment, and the thick pile segment and the thin pile segment are transitionally connected by the frustum-shaped pile segment.
9. A prefabricated pile as claimed in claim 1, characterized in that: Sleeves are pre-buried at both ends of the concrete pile body, and the ends of each main reinforcement are respectively connected and fixed to a corresponding sleeve.
10. The prefabricated pile according to claim 1, characterized in that: It also includes a hoops, wherein two hoops are respectively sleeved on the sleeves at both ends of the concrete pile body.