Prefabricated high-strength concrete composite pile
By designing precast high-strength concrete composite piles with enlarged pile bodies or end plates at one end of the precast pile, the problems of insufficient pile end resistance and material waste are solved, the pile body stiffness and bearing capacity are improved, and the construction difficulty and cost are reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-08
- Publication Date
- 2026-04-07
AI Technical Summary
Precast piles have limited bearing capacity under geological conditions of end-bearing piles and friction piles, making it difficult to fully utilize the pile end resistance. This leads to material waste and quality control issues during construction, especially in soft soil and hard rock formations.
A precast high-strength concrete composite pile is designed with an enlarged pile body or an enlarged end plate at one end of the core pile. The core pile is wrapped with reinforcement. By using the mixing and pre-drilling pile planting process, the contact area between the enlarged end plate and the bearing layer is increased. The end plate seals the inner hole of the core pile, thereby improving the pile body stiffness and bearing capacity.
It effectively increases the resistance at the pile end, reduces construction difficulty and material waste, improves the bearing capacity of the pile body, ensures the verticality and connection quality of the pile body, reduces environmental pollution, and lowers construction costs.
Smart Images
Figure CN224092469U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of building engineering, and in particular to a precast high-strength concrete composite pile. Background Technology
[0002] Prestressed concrete piles, as a high-efficiency, economical, and environmentally friendly foundation engineering material, have been widely used in modern construction projects. They possess significant advantages such as high pile bearing capacity, stable quality, fast construction speed, low overall cost, and environmental friendliness on-site. Therefore, in various construction projects, especially large-scale infrastructure projects such as high-rise buildings, bridges, and docks, prestressed concrete piles have become the preferred foundation type. However, with the deepening of engineering practice, some problems have also been exposed in the practical application of prestressed concrete piles. In particular, the current construction technology of pre-drilled holes and precast pipe piles exists in end-bearing pile geology, while in friction pile geology, there are construction technologies such as stiffened composite piles, mixing piles, and cement-soil composite pipe piles. However, the following problems have also been found in practical applications:
[0003] Question 1: Under end-bearing pile geological conditions, especially in geological environments with shallow rock layers or soft soil above and bedrock below, the rock-penetrating performance of precast piles is significantly limited. Due to the cross-sectional shape and material properties of precast piles, they often fail to achieve ideal embedment when penetrating hard rock layers, resulting in insufficient end-resistance. Therefore, in practical engineering, cast-in-place piles are more commonly used under end-bearing pile geological conditions, where concrete is poured on-site to enhance the bond between the pile tip and the rock layer.
[0004] In recent years, to overcome the limitations of precast piles in end-bearing geological conditions, the engineering community has successively introduced pre-drilling methods using equipment such as long augers, rotary drilling rigs, and down-the-hole hammers. The specific process involves first using these devices to pre-drill holes in the rock strata, then injecting filler material (such as cement grout or concrete) into the holes, and finally inserting the precast pipe piles into the holes. This process has improved the applicability of precast piles in end-bearing geological conditions to some extent, but their bearing capacity still mainly depends on the end resistance, which in turn depends on the cross-sectional area of the precast pipe pile and the strength of the concrete.
[0005] However, as precast pipe piles are precast components with a continuous length and uniform diameter, their cross-sectional shape is relatively simple, which is not conducive to further improving the end resistance. Because the end resistance of the pile is limited, the compressive bearing capacity of the precast pile itself often cannot be fully utilized, resulting in material waste.
[0006] Question 2: Under friction pile geological conditions, the bearing capacity of precast piles mainly depends on the lateral friction between the pile and the surrounding soil. In recent years, to enhance the bearing capacity of friction piles, the engineering community has successively developed new construction techniques such as rigid composite piles, mixing piles, and cement-soil composite pipe piles. These techniques involve mixing the soil with high-pressure jet grouting equipment and injecting cement slurry to form a cement-soil composite, then pressing or driving the precast pipe piles into the soil. This process, to a certain extent, improves the bonding force between the pile and the soil, enhancing the utilization of lateral friction.
[0007] However, despite the significant achievements of these new technologies in improving lateral friction, the end resistance of precast piles remains difficult to fully realize. Due to the limited net cross-sectional area of precast piles, the effect of end resistance in friction pile geology is relatively small, thus limiting the overall bearing capacity of the pile. This is particularly true in soft soil foundations, where the realization of end resistance is even more challenging, further impacting the bearing performance of precast piles.
[0008] Question 3: Traditional precast pipe pile installation methods suffer from material waste and quality control issues. Firstly, some projects do not use steel plates to seal the pile ends during construction, resulting in the borehole being filled with filler material. This not only increases material usage but also leads to waste. Furthermore, during the connection between the precast pile and the pile cap, the presence of filler material necessitates borehole cleaning, increasing the complexity and duration of the construction.
[0009] Secondly, while some projects use on-site welding of steel plates to seal the pile ends, which can reduce material waste to some extent, the welding quality is affected by factors such as weather and the skill level of on-site operators, making it difficult to guarantee the stability of the welding quality. Especially in some precast piles that require bottom sealing in their design, the instability of the welding quality may lead to incomplete sealing of the pile ends, thereby affecting the pile's bearing capacity and durability.
[0010] Furthermore, traditional precast pipe pile implantation methods face challenges during construction, including controlling pile verticality and insufficient bonding force between the pile tip and the soil. Due to soil resistance during implantation, the pile may become misaligned, resulting in verticality that fails to meet design requirements and consequently affecting its bearing capacity. Simultaneously, insufficient bonding force between the pile tip and the soil prevents the pile tip resistance from being fully utilized, further weakening its bearing capacity. Summary of the Invention
[0011] To address the shortcomings of existing technologies, this utility model provides a precast high-strength concrete composite pile, with one end of the core pile having an enlarged pile body or an enlarged end plate, which can achieve better stress performance. It has a reasonable structure, high pile body stiffness and strength, efficient production and manufacturing, and reliable construction quality.
[0012] This utility model achieves the above-mentioned technical objectives through the following technical means.
[0013] A precast high-strength concrete composite pile includes a core pile and a reinforcing body. The reinforcing body is wrapped around the outside of the core pile. One end of the core pile is provided with an enlarged end that is larger than the outer diameter of the core pile. The enlarged end includes an end plate that seals the inner hole of the core pile, thereby achieving better stress performance.
[0014] Furthermore, one end of the core pile is provided with an enlarged pile body, the outer diameter of which is larger than the outer diameter of the core pile body; an end plate is provided on the core pile located at one end of the enlarged pile body.
[0015] Furthermore, a gradually widening transition section is provided between the enlarged pile body and the core pile body.
[0016] Furthermore, the length of the enlarged pile body is 500–2000 mm.
[0017] Furthermore, the end plate is an enlarged end plate, the outline of which extends outward from the pile body of the core pile by at least 20mm.
[0018] Furthermore, the enlarged end plate extending outward from the core pile body is provided with a plurality of end plate reinforcing ribs, which are connected to the core pile body; the end plate reinforcing ribs are located within the reinforcement body.
[0019] Furthermore, the bearing capacity of the reinforcement is less than that of the core pile / enlarged pile body.
[0020] Furthermore, the material of the reinforcing body is concrete, cement mortar, or cement grout; the concrete strength of the core pile and the enlarged pile body is not less than C60.
[0021] Furthermore, a limiting device is provided on the outer surface of the core pile, and the limiting device is located within the reinforcement body.
[0022] Furthermore, the limiting device is a ring-shaped stirrup, and the distance between the outer side of the stirrup and the outer contour of the reinforcing body does not exceed 5cm.
[0023] A construction method for precast high-strength concrete composite piles includes the following steps:
[0024] Pre-machine pilot holes in the base layer and inject reinforcing material into the pilot holes;
[0025] The core pile is prefabricated, and one end of the core pile is provided with an enlarged end;
[0026] Insert the enlarged end of the core pile into the pilot hole.
[0027] A construction method for precast high-strength concrete composite piles includes the following steps:
[0028] The base layer is stirred, and the reinforcing material is injected into the base layer;
[0029] The core pile is prefabricated, and one end of the core pile is provided with an enlarged end;
[0030] The enlarged end of the core pile is pressed or driven into the foundation layer.
[0031] The beneficial effects of this utility model are as follows:
[0032] 1. The precast high-strength concrete composite pile of this utility model has an enlarged pile body or an enlarged end plate at one end of the core pile, which significantly increases the contact area with the bearing layer, resulting in high pile body stiffness and strength, effectively increasing end resistance and reducing costs.
[0033] 2. The precast high-strength concrete composite pile of this utility model has an end plate that seals the inner hole of the core pile. The end plate and the core pile are integrally formed, which reduces the construction difficulty and avoids the waste of filler material caused by the influx of filler material into the pile hole. At the same time, the end plate can further improve the bearing capacity of the pile end.
[0034] 3. The precast high-strength concrete composite pile of this utility model has a core pile made of high-strength concrete, which can effectively improve the bearing capacity of the pile body.
[0035] 4. The construction method of the precast high-strength concrete composite piles described in this utility model effectively solves the difficulty of precast piles being formed in hard soil layers through the mixing and pre-drilling pile planting processes. The mixing and pre-drilling pile planting process eliminates the need for mud pits, reducing construction measures and environmental pollution; the pre-drilling pile planting process reduces curing time and the number of steps required for steel cage fabrication. Simultaneously, it eliminates the soil displacement effect of the precast piles.
[0036] 5. The precast high-strength concrete composite pile of this utility model has a limiting device on the outer surface of the core pile, which facilitates the positioning of the core pile and controls the verticality error of the core pile. Furthermore, the limiting device is located on the outside of the core pile and can serve as a reinforcing cage for the reinforcement, thus increasing the strength of the reinforcement. Attached Figure Description
[0037] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are some embodiments of this utility model. For those skilled in the art, it is obvious that other drawings can be obtained from these drawings without creative effort.
[0038] Figure 1 This is a front view of the precast high-strength concrete composite pile described in Embodiment 1 of this utility model.
[0039] Figure 2This is a cross-sectional view of the precast high-strength concrete composite pile described in Embodiment 1 of this utility model.
[0040] Figure 3 This is a front view of the precast high-strength concrete composite pile described in Embodiment 2 of this utility model.
[0041] In the picture:
[0042] 1-Core pile; 1-1-Enlarged pile body; 1-2-End plate; 1-3-Transition section; 1-4-Enlarged end plate; 1-5-End plate reinforcement; 2-Reinforcing body; 2-1-Stirrup. Detailed Implementation
[0043] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.
[0044] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0045] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0046] like Figure 1As shown, the precast high-strength concrete composite pile of this utility model includes a core pile 1 and a reinforcing body 2. The reinforcing body 2 is wrapped around the outside of the core pile 1. One end of the core pile 1 is provided with an enlarged end larger than the outer diameter of the core pile 1. The enlarged end includes an end plate, which seals the inner hole of the core pile 1. The enlarged end can be an enlarged pile body 1-1 with an end plate, or it can be just an enlarged end plate 1-4. The contact area between the enlarged end and the bearing layer is significantly increased, resulting in high pile body stiffness and strength, which can effectively increase end resistance and reduce costs. By using the end plate to seal the inner hole of the core pile, the end plate and the core pile are integrally formed, reducing construction difficulty and avoiding waste of filler material caused by filler material flowing into the pile hole. At the same time, the end plate can further improve the bearing capacity of the pile end. If the enlarged end is an enlarged end plate 1-4, then the enlarged end plate 1-4 can be directly regarded as an enlarged end with an end plate.
[0047] Example 1
[0048] like Figure 1 and Figure 2 As shown, the precast high-strength concrete composite pile in Example 1 includes a core pile 1 and a reinforcing body 2. The core pile 1 in Example 1 is a precast pipe pile, which can also be a square hollow pile. One end of the core pile 1 is provided with an enlarged pile body 1-1, the outer diameter of which is larger than the outer diameter of the core pile 1. The bearing strength of the reinforcing body 2 is less than the bearing strength of the core pile 1 / enlarged pile body 1-1. Generally, the material of the reinforcing body 2 is concrete, cement mortar, or cement grout. The concrete strength of the core pile 1 and the enlarged pile body 1-1 is not lower than C60. The core pile 1 and the enlarged pile body 1-1 can be precast integrally. The contact area between the enlarged pile body 1-1 and the bearing layer is significantly increased, resulting in high pile stiffness and strength, which can effectively increase end resistance and reduce costs.
[0049] To improve the strength of the connection between the enlarged pile body 1-1 and the core pile 1, a gradually widening transition section 1-3 is provided between the enlarged pile body 1-1 and the core pile 1. In Example 1, the length of the enlarged pile body 1-1 is 500-2000 mm.
[0050] An end plate 1-2 is provided on the core pile 1 located at one end of the enlarged pile body 1-1. The end plate 1-2 seals the inner hole of the core pile 1, such as... Figure 1As shown, the inner hole here refers to the central hole of the core pile 1, which is the inner hole of the pipe pile. The thickness of the end plate 1-2 should not be less than 20mm, and the end plate 1-2 can be made of Q235B or Q355B steel plate. The core pile 1, the enlarged pile body 1-1, and the end plate 1-2 can be prefabricated as a whole in the factory, which can ensure the quality of the core pile 1 and reduce the construction difficulty. In addition, the end plate 1-2 seals the inner hole of the core pile, avoiding the waste of filler material caused by the influx of filler material into the pile hole. At the same time, the end plate can further improve the bearing capacity of the pile end. In Example 1, the outer diameter of the end plate 1-2 is not greater than the outer diameter of the core pile 1. In another embodiment, the outer diameter of the end plate 1-2 can also exceed the outer diameter of the core pile 1, but the outer diameter of the end plate 1-2 is smaller than the outer diameter of the reinforcing body 2.
[0051] like Figure 2 As shown, a limiting device is provided on the outer surface of the core pile 1, and the limiting device is located inside the reinforcement body 2. The limiting device is an annular stirrup 2-1, and the distance between the outer side of the stirrup 2-1 and the outer contour of the reinforcement body 2 does not exceed 5cm, that is, the diameter of the outer side of the stirrup 2-1 is at least 10cm smaller than the diameter of the outer contour of the reinforcement body 2. The annular stirrup 2-1 can prevent the core pile 1 from tilting during piling, ensuring the verticality of the core pile 1 in the formed composite pile. In addition, the annular stirrup 2-1 is located on the outside of the core pile 1, and it can serve as a steel cage for the reinforcement body 2, thus increasing the strength of the reinforcement body 2.
[0052] Example 2
[0053] like Figure 3 As shown, the precast high-strength concrete composite pile in Example 2 includes a core pile 1 and a reinforcing body 2. The core pile 1 in Example 2 is a precast pipe pile. One end of the core pile 1 is provided with an enlarged end plate 1-4, the outline of which extends outwards from the pile body of the core pile 1. The enlarged end plate 1-4 seals the inner hole of the core pile 1. The contact area between the enlarged end plate 1-4 and the bearing layer is significantly increased, resulting in high pile body stiffness and strength, effectively increasing end resistance and reducing costs. By using the enlarged end plate 1-4 to seal the inner hole of the core pile 1, waste of filler material caused by its influx into the pile hole is avoided, and the enlarged end plate 1-4 can further improve the pile end bearing capacity.
[0054] In Example 2, the outline of the enlarged end plate 1-4 extends outward from the pile body of the core pile 1 by at least 20mm. Several end plate reinforcing ribs 1-5 are evenly distributed on the enlarged end plate 1-4 extending outward from the pile body of the core pile 1. The end plate reinforcing ribs 1-5 are connected to the pile body of the core pile 1. The end plate reinforcing ribs 1-5 are located within the reinforcing body 2 and can support the pile end bearing capacity, further improving the pile end bearing capacity. The enlarged end plate 1-4 can be made of Q235B or Q355B steel plate. The core pile 1 and the enlarged end plate 1-4 can be prefabricated as a single unit in a factory, which ensures the quality of the core pile 1 and reduces construction difficulty. The longitudinal main reinforcement within the pile body of the core pile 1 can be prestressed steel strands, or a combination of prestressed and non-prestressed steel bars.
[0055] A limiting device is provided on the outer surface of the core pile 1, and the limiting device is located inside the reinforcement body 2. The limiting device is an annular stirrup 2-1, and the diameter of the stirrup 2-1 is 5-15 cm smaller than the outer diameter of the reinforcement body 2. The annular stirrup 2-1 can prevent the core pile 1 from tilting during piling and ensure the verticality of the core pile 1 in the formed composite pile. In addition, the annular stirrup 2-1 is located on the outside of the core pile 1, and it can serve as a steel cage for the reinforcement body 2, thus increasing the strength of the reinforcement body 2.
[0056] Example 3
[0057] The construction method for precast high-strength concrete composite piles according to this utility model includes the following steps:
[0058] The core pile 1 described in Example 1 or Example 2 is prefabricated, and one end of the core pile 1 is provided with an enlarged end; the enlarged end can be an enlarged pile body 1-1 or an enlarged end plate 1-4.
[0059] In soft soil foundations, pre-drilling holes are pre-drilled using equipment such as long spirals, rotary drilling, and down-the-hole hammers, and fluid plain concrete, cement mortar, cement grout, and other materials are injected into the pre-drilling holes to form reinforcement body 2;
[0060] Before the reinforcement 2 hardens, the enlarged end of the core pile 1 is inserted into the pilot hole, and mechanical equipment is used to compact the soil at the bottom of the pile through the core pile. In order to prevent the core pile 1 from tilting during pile driving, an annular stirrup 2-1 can be set on the outer surface of the core pile 1. The annular stirrup 2-1 can be a circle made of ordinary steel bars. The diameter of the stirrup 2-1 is 5-15cm smaller than the inner diameter of the pilot hole.
[0061] Example 4
[0062] The construction method for precast high-strength concrete composite piles according to this utility model includes the following steps:
[0063] The core pile 1 described in Example 1 or Example 2 is prefabricated, and one end of the core pile 1 is provided with an enlarged end; the enlarged end can be an enlarged pile body 1-1 or an enlarged end plate 1-4.
[0064] The hard soil layer is mixed by processes such as cement mixing, and cement slurry is injected into the hard soil layer to form reinforcement 2;
[0065] Before the reinforcement 2 hardens, the enlarged end of the core pile 1 is pressed or driven into the foundation layer. To prevent the core pile 1 from tilting during pile driving, an annular stirrup 2-1 can be provided on the outer surface of the core pile 1. The annular stirrup 2-1 can be a circle made of ordinary steel bars tied together. The diameter of the stirrup 2-1 is 5-15cm smaller than the inner diameter of the pilot hole.
[0066] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.
[0067] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present utility model, and are not intended to limit the scope of protection of the present utility model. All equivalent embodiments or modifications made without departing from the spirit of the present utility model should be included within the scope of protection of the present utility model.
Claims
1. A precast high-strength concrete composite pile, characterized in that, It includes a core pile (1) and a reinforcing body (2). The core pile (1) is wrapped with the reinforcing body (2). One end of the core pile (1) is provided with an enlarged end that is larger than the outer diameter of the core pile (1). The enlarged end includes an end plate (1-2) that blocks the inner hole of the core pile (1).
2. The precast high-strength concrete composite pile according to claim 1, characterized in that, The enlarged end includes an enlarged pile body (1-1), the outer diameter of which is larger than the outer diameter of the core pile (1); the end plate (1-2) is located at one end of the enlarged pile body (1-1).
3. The precast high-strength concrete composite pile according to claim 2, characterized in that, A gradually widening transition section (1-3) is provided between the enlarged pile body (1-1) and the core pile (1).
4. The precast high-strength concrete composite pile according to claim 2, characterized in that, The length of the enlarged pile body (1-1) is 500-2000 mm.
5. The precast high-strength concrete composite pile according to claim 1, characterized in that, The end plate (1-2) is an enlarged end plate (1-4), the outline of which extends outward from the pile body of the core pile (1), and the outline of which extends outward from the pile body of the core pile (1) by not less than 20mm.
6. The precast high-strength concrete composite pile according to claim 5, characterized in that, The enlarged end plate (1-4) extending outward from the pile body of the core pile (1) is provided with a plurality of end plate reinforcing ribs (1-5), the end plate reinforcing ribs (1-5) being connected to the pile body of the core pile (1); the end plate reinforcing ribs (1-5) being located inside the reinforcing body (2).
7. The precast high-strength concrete composite pile according to claim 1, characterized in that, The bearing capacity of the reinforcement (2) is less than that of the core pile (1) / enlarged pile body (1-1).
8. The precast high-strength concrete composite pile according to claim 7, characterized in that, The material of the reinforcing body (2) is concrete, cement mortar, or cement grout; the concrete strength of the core pile (1) and the enlarged pile body (1-1) is not less than C60.
9. The precast high-strength concrete composite pile according to claim 1, characterized in that, A limiting device is provided on the outer surface of the core pile (1), and the limiting device is located inside the reinforcement body (2).
10. The precast high-strength concrete composite pile according to claim 9, characterized in that, The limiting device is a ring-shaped stirrup (2-1), and the distance between the outer side of the stirrup (2-1) and the outer contour of the reinforcing body (2) does not exceed 5cm.