Composite prestressed pipe pile for strong weathered granite stratum

Abstract

The utility model discloses a kind of composite prestressed pipe pile for strong weathering granite stratum, solve the technical problem that traditional hollow pipe pile is when encountering hard strong weathering rock layer, huge punctate impact force and extrusion force are concentrated on pile tip and lower part of pile body, leading to concrete structure local stress too large and breakage. Including: pile pipe body, the pile pipe body is hollow prestressed concrete tubular structure;Pile tip, the pile tip is fixedly connected in the lower end of the pile pipe body;Internal reinforcing core, the internal reinforcing core is a metal core, is set in the hollow cavity of the lower part of the pile pipe body, and is connected with the pile tip, for transmitting and dispersing impact stress from pile tip in the process of sinking pile;And, annular gap formed between the internal reinforcing core and the inner wall of the pile pipe body is filled with reinforced concrete, so that the internal reinforcing core and pile pipe body form a whole.

Description

Technical Field

[0001] This utility model relates to the field of building engineering technology, and more specifically, to a composite prestressed pipe pile for strongly weathered granite strata. Background Technology

[0002] Strongly weathered granite strata are widely distributed in my country, especially in Guangdong and other areas, where undulating strata and dense fault formations are common. With the increasing scarcity of urban construction land, new land development is gradually expanding to the suburbs. A certain urban renewal project is located in Houlongshan, Jiulong Town, Huangpu District, Guangzhou. This area has significant strata undulations due to natural factors, and the strongly weathered granite strata are shallowly buried. Since strongly weathered rock strata generally have good mechanical properties (standard penetration test blow count generally >50 blows, side friction generally >200 kPa, end resistance generally >10000 kPa), when the tip of a prestressed high-strength concrete (PHC) pipe pile enters the strongly weathered rock strata, the enormous point impact and compressive forces concentrate on the pile tip and lower part of the pile body. This easily leads to excessive local stress in the concrete structure, causing damage and resulting in difficulties in pile driving, inability to drive the pile to the design elevation, weld detachment, and pile fracture.

[0003] To address the aforementioned issues, the current solution is to use other types of piles, such as steel pipe piles. While steel pipe piles possess excellent toughness, bending resistance, and impact resistance, enabling them to adapt well to complex stress conditions, their high cost and complex, costly corrosion protection methods limit their large-scale adoption. Utility Model Content

[0004] The purpose of this invention is to provide a composite prestressed pipe pile for use in strongly weathered granite strata, which solves the technical problem that when traditional hollow pipe piles encounter hard, strongly weathered rock strata, the huge point impact force and extrusion force are concentrated on the pile tip and the lower part of the pile body, resulting in excessive local stress and damage to the concrete structure.

[0005] This utility model provides a composite prestressed pipe pile for strongly weathered granite strata, comprising: a pile pipe body, which is a hollow prestressed concrete tubular structure; a pile tip, which is fixed to the lower end of the pile pipe body; and an internal reinforcing core, which is a metallic core disposed in the hollow cavity at the lower part of the pile pipe body and connected to the pile tip, for transmitting and dispersing impact stress from the pile tip during pile driving; and, the annular gap formed between the internal reinforcing core and the inner wall of the pile pipe body is filled with reinforced concrete so that the internal reinforcing core and the pile pipe body form an integral whole.

[0006] As an optimization and / or instance of the above-mentioned composite prestressed pipe piles for strongly weathered granite strata, further: the upper end of the internal reinforcing core extends into the interior of the pile pipe body, and its lower end is fixedly connected to the base of the pile tip.

[0007] As an optimization and / or instance of the above-mentioned composite prestressed pipe piles for strongly weathered granite strata, further: the internal reinforcing core is a solid or hollow steel column, H-beam, or steel pipe structure.

[0008] As an optimization and / or instance of the above-mentioned composite prestressed pipe piles for strongly weathered granite strata, further: the reinforced concrete is non-shrink cement-based reinforced concrete or epoxy resin reinforced concrete.

[0009] As an optimization and / or instance of the above-mentioned composite prestressed pipe piles for strongly weathered granite strata, further: the pile tip is made of wear-resistant alloy steel or high manganese steel, and its shape is a cross-shaped structure or a conical structure.

[0010] As an optimization and / or instance of the above-mentioned composite prestressed pipe piles for strongly weathered granite strata, further: an integrally formed connecting sleeve is provided on the base of the pile tip, and the lower end of the internal reinforcing core is inserted into the connecting sleeve and fixed by welding or threaded connection.

[0011] As an optimization and / or instance of the above-mentioned composite prestressed pipe piles for strongly weathered granite strata, further: the length of the internal reinforcing core is 1 / 10 to 1 / 3 of the total length of the pile pipe body, and its setting range covers the lower section of the pile body that is mainly subjected to force during pile driving.

[0012] As an optimization and / or instance of the above-mentioned composite prestressed pipe piles for strongly weathered granite strata, further: an external reinforcing steel sleeve is also fitted on the lower part of the outer wall of the pile pipe body.

[0013] As an optimization and / or instance of the above-mentioned composite prestressed pipe piles for strongly weathered granite strata, further: the pile body is a prestressed high-strength concrete pipe pile.

[0014] As an optimization and / or instance of the aforementioned composite prestressed pipe piles for strongly weathered granite strata, further: the internal reinforcing core is a casting, which consists of a tungsten-based high-density alloy core and a cast steel outer shell covering the tungsten-based high-density alloy core, wherein the density of the tungsten-based high-density alloy core is not less than 17.0 g / cm³. 3 .

[0015] The composite prestressed pipe piles for strongly weathered granite strata provided by this utility model have produced significant beneficial effects:

[0016] First, by setting an internal reinforcing core that is directly connected to the pile tip, the huge impact stress borne by the pile tip during the pile driving process is directly transferred to the internal reinforcing core. Then, the stress is evenly distributed to the pile tube body by the filled reinforced concrete, which greatly improves the overall impact resistance and compressive strength of the lower part of the pile body, ensures the integrity of the pile structure during the hammering process, and avoids the risk of pile body cracking or breaking.

[0017] Secondly, because the lower structure of the pile has been fundamentally strengthened, it can withstand greater hammering energy, enabling the pipe piles to penetrate hard bearing layers such as strongly weathered granite strata smoothly and efficiently, and reliably drive the piles to the design elevation. This not only ensures the bearing capacity of a single pile and avoids engineering hazards caused by incomplete pile driving, but also reduces rework or abandoned piles due to pile fracture or damage, significantly saving construction costs and time.

[0018] Third, a composite structure design with local reinforcement is adopted, with internal reinforcing cores only installed in the lower section of the pile body that bears the main force during pile driving. Compared with the scheme of using steel pipe piles as the whole, this scheme achieves superior impact resistance while significantly reducing material costs, providing a highly cost-effective technical option for the application of high-performance pile foundations in hard strata.

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages provided by the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice. Attached Figure Description

[0020] The accompanying drawings, which form part of this specification, are used to aid in understanding the present invention. The contents provided in the drawings and their related descriptions in this specification can be used to explain the present invention, but do not constitute an undue limitation on the present invention.

[0021] Figure 1 This is a schematic diagram of a composite prestressed pipe pile for use in strongly weathered granite strata, according to an embodiment of the present invention.

[0022] Figure 2 for Figure 1 The diagram shown is a cross-sectional view of section AA in a composite prestressed pipe pile used in strongly weathered granite strata.

[0023] Figure 3 for Figure 1 The diagram shows a structural schematic of one embodiment of the internal reinforcing core in a composite prestressed pipe pile used in strongly weathered granite strata.

[0024] The components are marked as follows: 1. Pile pipe body, 2. Pile tip, 21. Connecting sleeve, 3. Internal reinforcing core, 31. Tungsten-based high-density alloy core, 32. Steel outer shell, 4. Reinforced concrete, 5. External reinforcing steel sleeve. Detailed Implementation

[0025] The present invention will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0026] The technical solutions and features provided in the various sections, including the following description, can be combined with each other without conflict. Furthermore, where possible, these technical solutions, features, and related combinations can be given specific technical subject matter and protected by relevant patents.

[0027] The embodiments of the present invention described below are generally only some embodiments and not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of patent protection.

[0028] The terms "comprising," "including," "having," and any variations thereof in this specification, the corresponding claims, and related sections are intended to cover non-exclusive inclusion. Other related terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0029] like Figure 1 As shown in the figure, the present invention provides a composite prestressed pipe pile for strongly weathered granite strata, which mainly includes a pile pipe body 1, a pile tip 2 fixed to the lower end of the pile pipe body 1, and an internal reinforcing core 3 disposed in the hollow cavity at the lower part of the pile pipe body 1.

[0030] Specifically, the pile body 1 is a hollow prestressed concrete tubular structure, preferably a prestressed high-strength concrete (PHC) pipe pile, to provide the foundation with axial bearing capacity and bending resistance.

[0031] The pile tip 2 is fixed to the lower end of the pile pipe body 1 and is used to break soil and crush rock during pile driving. To adapt to hard strata such as strongly weathered granite, the pile tip 2 is preferably made of wear-resistant alloy steel or high manganese steel, and its shape can be a cross-shaped structure or a conical structure for efficient piercing.

[0032] The key structure of this utility model lies in the provision of an internal reinforcing core 3. This internal reinforcing core 3 is a metallic core, the lower end of which is fixedly connected to the base of the pile tip 2, and the upper end of which extends upward into the interior of the pile tube body 1.

[0033] Preferably, the length of the internal reinforcing core 3 is 1 / 10 to 1 / 3 of the total length of the pile pipe body 1. This setting range can effectively cover the lower section of the pile body where the hammering stress is most concentrated during pile driving.

[0034] In order to achieve a reliable connection between the internal reinforcing core 3 and the pile tip 2, a preferred connection method is to provide an integrally formed connecting sleeve 21 on the base of the pile tip 2, insert the lower end of the internal reinforcing core 3 into the connecting sleeve 21, and fix it firmly by welding or threaded connection.

[0035] In some embodiments, in order to further enhance the circumferential constraint force at the lower part of the pile body and prevent the pile head from radially cracking under huge impact, an external reinforcing steel sleeve 5 can also be fitted on the lower part of the outer wall of the pile pipe body 1.

[0036] Please see Figure 2 The figure more clearly illustrates the composite structure at the bottom of the pile. As can be seen from the figure, the internal reinforcing core 3 is located at the center of the hollow cavity of the pile tube body 1. An annular gap is formed between the internal reinforcing core 3 and the inner wall of the pile tube body 1, and this gap is filled with reinforced concrete 4.

[0037] This filling ensures a tight bond between the internal reinforcing core 3, the reinforced concrete 4, and the pile pipe body 1, forming a robust whole. To guarantee the bonding effect, the reinforced concrete 4 is preferably non-shrink cement-based reinforced concrete or epoxy resin reinforced concrete to prevent shrinkage gaps after curing, ensuring the continuity and effectiveness of stress transmission.

[0038] Please see Figure 3 In one optional embodiment, the internal reinforcing core 3 is a casting, consisting of a high-density tungsten-based high-density alloy core 31 and a steel outer shell 32 that is cast around the tungsten-based high-density alloy core 31. The density of the tungsten-based high-density alloy core 31 is not less than 17.0 g / cm³.

[0039] Tungsten-based high-density alloys are existing composite materials with metallic tungsten as the matrix (usually with a weight percentage of 90%-98%) and small amounts of elements such as nickel, iron, copper, and cobalt added as binder phases. Known applications include ballast materials in the aerospace field.

[0040] By adopting the above-mentioned composite structure, the extremely high density and mass of tungsten-based high-density alloy can be fully utilized to provide strong impact inertia and energy absorption capacity. At the same time, the good toughness and weldability of the outer steel shell 32 can be used to facilitate reliable fixation with the connecting sleeve 21 of the pile tip 2, and can form a good interface bond with the filled reinforced concrete 4.

[0041] It should be noted that the structure of the internal reinforcing core 3 is not limited to... Figure 3 The composite casting shown. In other embodiments, depending on specific engineering requirements and cost considerations, the internal reinforcing core 3 can also be a solid or hollow steel column, H-beam, or steel pipe structure, which similarly serves to transfer and disperse impact stress.

[0042] The working principle of the composite prestressed pipe piles used in strongly weathered granite strata is as follows: During pile driving, the enormous impact force generated by the hammering equipment acts on the pile top and is transmitted to the pile tip 2 through the pile body. When the pile tip 2 encounters a hard bearing layer such as strongly weathered granite, it generates a huge point reaction force. This impact stress is first transmitted from the pile tip 2 to the internal reinforcing core 3, which is directly and rigidly connected to it. Since the internal reinforcing core 3 is a high-strength metallic core (especially when using the aforementioned castings), it can withstand and effectively transmit this concentrated impact energy. Subsequently, the stress is evenly distributed to a larger area of ​​the lower section of the pile body 1 through the composite whole formed by the internal reinforcing core 3 and the filled reinforced concrete 4, thereby avoiding stress concentration, improving the overall impact resistance and compressive strength of the lower part of the pile body, ensuring the integrity of the pile structure during the hammering process, and effectively avoiding the risk of pile body cracking or breakage.

[0043] The foregoing has described the relevant content of this utility model. Those skilled in the art will be able to implement this utility model based on these descriptions. All other embodiments obtained by those skilled in the art based on the foregoing content of this specification without inventive effort should fall within the scope of this utility model.

Claims

1. A composite prestressed pipe pile for use in strongly weathered granite strata, comprising: The pile pipe body (1) is a hollow prestressed concrete tubular structure. The pile tip (2) is fixed to the lower end of the pile pipe body (1); Its features are: It also includes an internal reinforcing core (3), which is a metallic core that is set in the hollow cavity at the bottom of the pile pipe body (1) and connected to the pile tip (2) to transmit and disperse the impact stress from the pile tip (2) during the pile driving process. Furthermore, reinforced concrete (4) is filled in the annular gap formed between the inner reinforcing core (3) and the inner wall of the pile pipe body (1) so that the inner reinforcing core (3) and the pile pipe body (1) form an integral whole.

2. The composite prestressed pipe pile for strongly weathered granite strata as described in claim 1, characterized in that: The upper end of the internal reinforcing core (3) extends into the interior of the pile pipe body (1), and its lower end is fixedly connected to the base of the pile tip (2).

3. The composite prestressed pipe pile for strongly weathered granite strata as described in claim 1, characterized in that: The internal reinforcing core (3) is a solid or hollow steel column, H-beam or steel pipe structure.

4. The composite prestressed pipe pile for strongly weathered granite strata as described in claim 1, characterized in that: The reinforced concrete (4) is non-shrink cement-based reinforced concrete or epoxy resin reinforced concrete.

5. The composite prestressed pipe pile for strongly weathered granite strata as described in claim 1, characterized in that: The pile tip (2) is made of wear-resistant alloy steel or high manganese steel, and its shape is a cross-shaped structure or a conical structure.

6. The composite prestressed pipe pile for strongly weathered granite strata as described in claim 1, characterized in that: The base of the pile tip (2) is provided with an integrally formed connecting sleeve (21), and the lower end of the internal reinforcing core (3) is inserted into the connecting sleeve (21) and fixed by welding or threaded connection.

7. The composite prestressed pipe pile for strongly weathered granite strata as described in claim 1, characterized in that: The length of the internal reinforcing core (3) is 1 / 10 to 1 / 3 of the total length of the pile pipe body (1), and its installation range covers the lower section of the pile body that is mainly subjected to force during pile driving.

8. The composite prestressed pipe pile for strongly weathered granite strata as described in claim 1, characterized in that: An external reinforcing steel sleeve (5) is also fitted on the lower part of the outer wall of the pile pipe body (1).

9. The composite prestressed pipe pile for strongly weathered granite strata as described in claim 1, characterized in that: The pile body (1) is a prestressed high-strength concrete pipe pile.

10. The composite prestressed pipe pile for strongly weathered granite strata as described in claim 1, characterized in that: The internal reinforcing core (3) is a casting, which consists of a tungsten-based high-density alloy core (31) and a steel outer shell (32) cast and covering the tungsten-based high-density alloy core (31). The density of the tungsten-based high-density alloy core (31) is not less than 17.0 g / cm³. 3 .

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