Precast pile
By adopting a cage-like design and sleeve connection in precast concrete pipe piles, controlling the circumferential deflection angle of the main reinforcement, and combining the alternating design of thick and thin pile segments, the problems of insufficient bearing capacity and prestress loss of precast concrete pipe piles are solved, thereby improving the stability and construction adaptability of the structure.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NINGBO ZHONGCHUN HIGH-TECH CO LTD
- Filing Date
- 2025-04-09
- Publication Date
- 2026-05-12
AI Technical Summary
The bearing capacity of existing precast concrete pipe piles still has significant room for improvement, and there is a risk of prestress loss and main reinforcement fracture under the straight shape design, which affects the safety and stability of the structure.
The design adopts a cage-like skeleton, with the main reinforcement deflected at an angle α less than the central angle θ along the circumference of the concrete pile, and α ≥ 0.5° and ≤ 1/2θ. Combined with the alternating design of thick and thin pile segments and sleeve connection, the end plate is fixed to the end of the main reinforcement, and the sleeve provides additional restraint.
It enhances the overall stability and load-bearing capacity of the structure, reduces prestress loss, optimizes construction flexibility and adaptability, and improves the durability and safety of the structure.
Smart Images
Figure CN224227772U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to building material technical field relates to a precast pile. BACKGROUND
[0002] The prefabricated concrete pipe pile is widely used in various construction engineering scenes due to its excellent mechanical properties and convenient construction. In the foundation engineering of high-rise residential buildings, commercial buildings and super high-rise buildings, the concrete pipe pile becomes an ideal foundation material selection due to its high bearing capacity and good stability. Especially under the condition of soft soil foundation, by using prestressed high-strength concrete pipe pile (PHC pile), the foundation settlement can be effectively reduced to ensure the safety and stability of the building.
[0003] At present, the prefabricated concrete pipe pile on the market is formed by pouring concrete into a main reinforcement array composed of main reinforcement. The angle of the main reinforcement projection at both ends is usually 0°. According to conventional engineering cognition, keeping the main reinforcement straight helps to maximize the bearing capacity of the prefabricated concrete pipe pile, because the straight shape can more effectively transfer the load and reduce stress concentration points, thereby ensuring the overall stability and strength of the structure.
[0004] However, with the development of engineering technology and the in-depth study of material properties, people have found that even under this so-called "optimal design", the bearing capacity of the prefabricated concrete pipe pile still has room for significant improvement. SUMMARY
[0005] The utility model aims at the above-mentioned problems existing in prior art, and provides a prefabricated pile, which comprises:
[0006] A cage reinforcement framework composed of a main reinforcement array formed by circumferentially arranging a plurality of main reinforcements and stirrups arranged around the main reinforcement array;
[0007] A concrete pile body poured into the cage reinforcement framework;
[0008] In the projection of the length direction of the concrete pile body, one end of the main reinforcement is circumferentially deflected by an angle a relative to the other end of the main reinforcement.
[0009] In the above-mentioned prefabricated pile, the central angle between the two adjacent main reinforcements is θ, and the deflection angle a is less than the central angle θ.
[0010] In the above-mentioned prefabricated pile, the deflection angle a 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 prefabricated pile, the deflection angle a is less than or equal to 1 / 2 of the central angle θ, and the circumferential deflection angles of the main reinforcements are the same.
[0012] In the precast pile, the deflection angle a is 0-3 degrees, and the main reinforcement is uniformly deflected along the circumference in the length direction of the concrete pile body.
[0013] In the precast pile, two end plates are arranged at two ends of the concrete pile body, and the end plates are provided with end holes, and the end portions of the main reinforcement are installed in the end holes.
[0014] In the precast pile, the end holes include anchor holes, wire holes and wire grooves, and the anchor holes and the wire holes are connected through the wire grooves.
[0015] In the precast pile, the concrete pile body is provided with thick pile sections and thin pile sections, the thick pile sections and the thin pile sections are arranged alternately in sequence in the length direction of the concrete pile body, and the concrete pile body is further provided with frustum-shaped pile sections, and the thick pile sections and the thin pile sections are transitionally connected by the frustum-shaped pile sections.
[0016] In the precast pile, sleeves are pre-buried at two ends of the concrete pile body, and the end portions of each main reinforcement are connected and fixed with one corresponding sleeve.
[0017] In the precast pile, two sleeves are arranged at two ends of the concrete pile body.
[0018] Compared with the prior art, the precast pile has the advantages that:
[0019] 1. Controlling the axial deflection of the main reinforcement helps to reduce the loss of prestress. Prestress technology applies pressure to the concrete in advance to offset the tensile stress caused by external loads, thereby increasing the service life and load-carrying capacity of the structure.
[0020] 2. The deflection angle of the main reinforcement is limited according to the number of main reinforcements. If the axial deflection of the main reinforcement is too large, not only will the prestress be lost, but also the risk of breaking the end of the main reinforcement will be caused, which will seriously affect the safety of the structure.
[0021] 3. The deflection angle a is set to at least 0.5 degrees, which can ensure that each main reinforcement has a minimum deflection angle. This not only helps to enhance the overall stability of the structure, but also effectively disperses the influence of external force 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 the precast pile engineering, which not only helps to fully exert the side friction and end bearing of the precast pile, thereby significantly improving the overall mechanical bearing performance of the pile body, but also effectively optimizes the stability and durability of the whole structure, the tapered transition pile section is added between the thick pile section and the thin pile section, which eliminates or reduces the stress concentration problem that may occur in the pile body, and ensures the safety and reliability of the pile body in long-term use.
[0023] 5、By using the sleeve to connect two concrete pile bodies, the various challenges caused by the length limitation of the concrete pile in the transportation process are greatly broken, after adopting the sleeve connection mode, the length of the single concrete pile body is no longer a fixed restrictive factor, this mode not only ensures the integrity and stability of the pile body structure, but also significantly improves the construction flexibility and adaptability, whether in narrow urban space or in remote areas with inconvenient transportation, the appropriate pile length can be customized according to the actual needs, and the limitation caused by the transportation problem does not need to be worried. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 It is a structural schematic view of the utility model.
[0025] Figure 2 It is a schematic view of the cage skeleton of the utility model.
[0026] Figure 3 It is a schematic view of the end plate of the utility model.
[0027] Figure 4 It is a schematic view of the end hole of the utility model.
[0028] Figure 5 It is a schematic view of the sleeve of the utility model.
[0029] In the drawing:
[0030] 1, cage skeleton; 11, main reinforcement; 12, stirrup; 2, concrete pile body; 21, thick pile section; 22, thin pile section; 23, tapered pile section; 3, end plate; 31, end hole; 311, anchor hole; 312, reinforcing hole; 313, reinforcing groove; 4, sleeve. DETAILED DESCRIPTION
[0031] The following is a specific embodiment of the utility model and further describes the technical scheme of the utility model in combination with the drawings, but the utility model is not limited to these embodiments.
[0032] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.
[0033] Furthermore, in this utility model, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, features defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly and specifically defined.
[0034] In this utility model, unless otherwise explicitly specified and limited, the terms "connection" and "fixation" should be interpreted broadly. For example, "fixation" can be a fixed connection, a detachable connection, or an integral part; 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 components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0035] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0036] The specific embodiments described herein are merely illustrative examples of this utility model patent. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or adopt similar methods to replace them, but without departing from the patent of this utility model or exceeding the scope defined by the appended claims.
[0037] like Figures 1-5 As shown, a precast pile includes: a reinforcing cage 1 and a concrete pile body 2.
[0038] The cage frame 1 is composed of a main bar array 11 formed by several main bars 11 arranged in a circumferential direction and stirrups 12 arranged around the main bar array 11.
[0039] The concrete pile body 2 is cast into 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, the one end of the main reinforcement 11 is deflected by an angle α in the circumferential direction relative to the other end of the main reinforcement 11.
[0041] Specifically, the hoop reinforcement 12 can fix a plurality of circumferentially arranged main reinforcements 11 before pouring, preventing uneven distribution of the main reinforcement 11 on the concrete pile body 2 caused by positional deviation of the main reinforcement 11 during pouring of the concrete pile body 2, thereby causing stress concentration.
[0042] In the present embodiment, controlling the axial deflection of the main reinforcement 11 helps to reduce the loss of prestress, and the prestress technology can offset the tensile stress caused by external load by applying pressure to the concrete in advance, thereby increasing the service life and carrying capacity of the structure.
[0043] As shown in Figures 1-5 On the basis of the above embodiment, the central angle between the two adjacent main reinforcements 11 is θ, and the deflection angle α is less than the central angle θ.
[0044] In the present embodiment, the deflection angle of the main reinforcement 11 is limited according to the number of main reinforcements 11. If the axial deflection of the main reinforcement 11 is too large, not only will it cause loss of prestress, but it may also cause the risk of breaking the end of the main reinforcement 11, which will seriously affect the safety of the structure.
[0045] As shown in Figures 1-5 On the basis of the above embodiment, the deflection angle α is greater than or equal to 0.5°, and the circumferential deflection directions of the main reinforcements 11 are the same.
[0046] In the present 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 influence of external force on a single main reinforcement 11, making the entire structure more solid and durable.
[0047] As shown in Figures 1-5 On the basis of the above embodiment, 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 reinforcements 11 are the same.
[0048] In the present embodiment, reasonable arrangement and angle of the main reinforcement 11 are crucial 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 main reinforcements 11 can also meet the standard requirements. By limiting the deflection angle of the main reinforcement 11 and ensuring that the main reinforcements 11 maintain uniform spacing, the carrying capacity of the prefabricated pile can be effectively enhanced.
[0049] As shown in Figures 1-5As shown, based on the above implementation method, the deflection angle α ranges from 0° to 3°, and the main reinforcement 11 deflects uniformly along the circumference 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 that could lead to prestress loss or breakage of the main reinforcement 11. By reasonably selecting the deflection angle, the bond strength between the main reinforcement 11 and the concrete can be ensured to reach the optimal state, thereby enhancing the bearing capacity and durability of the entire structure.
[0051] like Figures 1-5 As shown, based on the above embodiment, it also includes end plates 3. The two end plates 3 are respectively disposed at both ends of the concrete pile body 2. 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 so that it passes through the end hole 31 and connects 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 performance between the various parts of the pile body and improves the pile body's ability to resist external loads. The end plate 3 helps to distribute the externally applied load more evenly on the pile body section, 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 Figures 1-5 As shown, based on the above embodiment, the end hole 31 includes an anchor hole 311, a through hole 312, and a through groove 313, and the anchor hole 311 and the through hole 312 are connected through the through groove 313.
[0054] Specifically, the outer diameter of the upset end of the main reinforcement 11 is smaller than the diameter of the through hole 312 but larger than the minimum diameter of the stepped hole of the anchor hole 311. The width of the through groove 313 is also smaller than the outer diameter of the upset end of the main reinforcement 11. In this way, after the upset end of the main reinforcement 11 is upset, it first passes through the through hole 312 and then slides into the anchor hole 311 through the through groove 313. The stepped surface of the upset end of the main reinforcement 11 abuts and is fixed with the stepped surface of the stepped hole of the anchor hole 311.
[0055] In this embodiment, the ends of the main reinforcement 11 can be upset in advance through the anchor hole 311, the through hole 312 and the through groove 313, and then the end plate 3 can be installed, which simplifies the complicated installation process and improves construction efficiency.
[0056] The AB type hollow precast pile with outer diameter of 400mm, 500mm, 600mm and 800mm is simulated and analyzed by using FLAC 3D 6.0 software, the pile body is defined as linear elastic material, the grid number is 3872, and the linear hexahedron is used, wherein the material mechanics parameter values 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 are selected as shown in Table 1:
[0057] Table 1: Pile body concrete mechanics parameter value
[0058]
[0059] The elastic modulus E, yield strength fy, ultimate strength fu and maximum elongation rate Agt of the main reinforcement are shown in Table 2, and the experimental data are shown in Table 3:
[0060] Table 2: Main reinforcement (prestressed steel bar) mechanics parameter value
[0061]
[0062] Table 3: Ultimate bending capacity simulation experiment value
[0063]
[0064]
[0065] From the data in Table 3, for hollow pipe piles with different outer diameter sizes, the circumferential deflection angle a 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 capacity of the pile body.
[0066] As shown in Figures 1-5 , on the basis of the above embodiment, the concrete pile body 2 is provided with a thick pile section 21 and a thin pile section 22, the thick pile section 21 and the thin pile section 22 are alternately arranged along the length direction of the concrete pile body 2, and the concrete pile body 2 is further provided with a frustum-shaped pile section 23, and the thick pile section 21 and the thin pile section 22 are transitionally connected by the frustum-shaped pile section 23.
[0067] In the present embodiment, the design of thick-thin alternation is particularly important in the precast pile engineering, which not only helps to fully exert the side friction and end bearing capacity of the precast pile, thereby significantly improving the overall mechanical bearing performance of the pile body, but also effectively optimizes the stability and durability of the whole structure, and the frustum-shaped transition pile section is added between the thick pile section 21 and the thin pile section 22, so as to eliminate or reduce the stress concentration problem that may occur in the pile body, and ensure the safety and reliability of the pile body in long-term use.
[0068] As shown in Figures 1-5As shown, based on the above implementation method, sleeves (not shown in the figure) are pre-embedded at both ends of the concrete pile body 2, and the ends of each main reinforcement 11 are respectively connected and fixed to one of the corresponding sleeves.
[0069] Specifically, due to transportation limitations, the length of the concrete pile body 2 is typically between 7 and 15 meters, but the concrete pile body 2 used in pile foundations is usually between 40 and 60 meters. This necessitates the segmented molding and manufacturing of the concrete pile body 2 in the factory, followed by on-site splicing. The concrete pile body 2, in its length direction (i.e., Figure 1 Sleeves are pre-embedded at both ends of the main reinforcement bar 11 (in the direction indicated by the middle arrow Z). The ends of each main reinforcement bar 11 are respectively connected and fixed to their corresponding sleeves. The sleeves have cavities exposed on the pile end face. During construction, the lower sleeve of the upper concrete pile body 2 is connected and fixed to the upper sleeve of the lower concrete pile body 2.
[0070] In this embodiment, by using a sleeve to connect two concrete piles 2, the various challenges caused by the length limitation of concrete piles during transportation are greatly overcome. After adopting the sleeve connection method, the length of a single concrete pile 2 is no longer a fixed constraint. This method not only ensures the integrity and stability of the pile structure, but also significantly improves the flexibility and adaptability of construction. 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.
[0071] like Figures 1-5 As shown, based on the above embodiment, it also includes a sleeve 4, with two sleeves 4 respectively fitted onto the sleeves at both ends of the concrete pile body 2.
[0072] In this embodiment, the sleeve 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 seismic action, the sleeve 4 can effectively prevent the concrete pile body 2 from shearing failure by providing additional constraints.
Claims
1. A precast pile, characterized in that, include: The cage skeleton consists of a main reinforcement array formed by several main reinforcement bars arranged in a circumferential direction and stirrups arranged around the main reinforcement array. The concrete pile body is cast into the aforementioned reinforcing cage. On the projection along the length of the concrete pile, one end of the main reinforcement bar is deflected by an angle α relative to the other end of the main reinforcement bar along the circumference of the concrete pile.
2. A precast pile as described in claim 1, characterized in that: The central angle between two adjacent main reinforcing bars is θ, and the deflection angle α is less than the central angle θ.
3. A precast pile as described in claim 2, characterized in that: The deflection angle α is greater than or equal to 0.5°, and the circumferential deflection direction of each main reinforcement is the same.
4. A precast pile as described 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 angle of each of the main reinforcement bars is the same.
5. A precast pile as described in claim 4, characterized in that: The deflection angle α ranges from 0° to 3°, and the main reinforcement is uniformly deflected circumferentially along the length of the concrete pile.
6. A precast pile as described in claim 1, characterized in that: It also includes end plates, two of which are respectively disposed at both ends of the concrete pile body. The end plates are provided with end holes, and the ends of the main reinforcement bars are installed in the end holes.
7. A precast pile as described in claim 6, characterized in that: The end hole includes an anchor hole, a through hole, and a through groove, and the anchor hole and the through hole are connected through the through groove.
8. A precast pile as described in claim 1, characterized in that: The concrete pile body is provided with coarse pile segments and fine pile segments, which are arranged alternately along the length of the concrete pile body. The concrete pile body is also provided with frustum-shaped pile segments, and the coarse pile segments and fine pile segments are connected by the frustum-shaped pile segments.
9. A precast pile as described in claim 1, characterized in that: Sleeves are pre-embedded at both ends of the concrete pile body, and the ends of each main reinforcement bar are respectively connected and fixed to one of the corresponding sleeves.
10. A precast pile as described in claim 1, characterized in that: It also includes sleeves, two of which are respectively fitted onto sleeves at both ends of the concrete pile body.