Combined steel pipe pile

Abstract

The utility model discloses a combined steel pipe pile, and belongs to the technical field of building foundation engineering. Comprising a hollow steel pipe pile with a bottom opening and a cement-soil mixture in a drill hole, which are combined to form the combined steel pipe pile. The hollow steel pipe pile is composed of a plurality of pipe sections which are connected end to end, and annular ribs, fan-shaped ribs or spiral ribs are arranged on the outer diameter of the hollow steel pipe pile and used for enhancing mechanical occlusion with cement soil stirring objects. The ribs are made of steel plates or twisted steel. The adjacent pipe sections are connected in an inserted mode through sleeves or fixed through flange bolts, the steel pipe piles are inserted before cement-soil stirring materials are solidified during construction, and soil plugs are formed and solidified. Through the design of the open steel pipes and the convex ribs, the pile sinking and soil squeezing effect is remarkably reduced, meanwhile, the pile-soil interface friction coefficient and the overall bearing capacity are improved, and the pile is suitable for engineering such as foundation pit supporting and foundation reinforcement and has the advantages of being convenient to construct and high in stability.

Description

Technical Field

[0001] This utility model relates to the field of building foundation engineering technology, specifically to a composite steel pipe pile. Background Technology

[0002] With the continuous expansion of infrastructure construction in my country, composite pile technology has been widely used in engineering fields such as building foundations and foundation pit support. Traditional composite pile structures mostly adopt the combination of cement-soil mixing piles and precast piles, but in actual engineering applications, technical bottlenecks such as insufficient bearing capacity and large construction disturbances have been exposed. Existing technical solutions, represented by the published patent "A Reinforced Composite Pile CN217128208 U", form reinforced composite piles by implanting concrete pile cores into cement-soil mixing piles. Although this improves the strength of the pile body to a certain extent, it has significant defects: First, the surface smoothness of the concrete pile core is relatively high, making it difficult to form an effective mechanical interlock with the cement-soil mixing pile body; second, the soil squeezing effect generated during the closed-end pile driving process of the precast concrete pile core is relatively severe, which can easily cause engineering problems such as displacement of adjacent pile positions and heave of surrounding soil. Utility Model Content

[0003] This invention provides a novel composite steel pipe pile, which replaces the traditional concrete pile core with an open steel pipe with ribbed outer wall, effectively reducing the soil compression effect during pile driving and significantly increasing the friction coefficient between the pile and soil interface. To achieve the above objectives, the technical solution of this invention is as follows:

[0004] A composite steel pipe pile is formed by inserting a steel pipe pile with an opening at the bottom into a mixing material in a borehole. The steel pipe pile has one or more hollow steel pipes connected end to end. The outer diameter of the hollow steel pipe is provided with ribs to enhance the bonding force with the mixing material. The ribs are annular ribs, fan-shaped ribs and / or spiral ribs installed on the outer diameter of the hollow steel pipe.

[0005] Furthermore, the mixing material is a cement-soil pile formed by high-pressure jet grouting or mixing, and the admixture of the cement-soil pile is one or more combinations of curing agent, cement, fly ash, etc.

[0006] Furthermore, the annular ribs and / or the fan-shaped ribs are arranged and fixed around the outer diameter of the hollow steel pipe at equal or arbitrary intervals along the axial direction of the steel pipe pile.

[0007] Furthermore, the annular rib, the fan-shaped rib, and / or the spiral rib are steel plates.

[0008] Furthermore, the annular rib, the fan-shaped rib, and / or the spiral rib are provided with a plurality of through holes in the thickness direction.

[0009] Furthermore, the annular ribs, the fan-shaped ribs, and / or the spiral ribs are steel bars.

[0010] Furthermore, the annular rib is either an integrally formed annular steel plate or two semi-circular steel plates.

[0011] Furthermore, the annular rib, the fan-shaped rib, and / or the spiral rib are welded with a plurality of reinforcing elbow plates between the steel pipe pile and the outer wall of the hollow steel pipe on one or both sides of the axial direction. The reinforcing elbow plates are one or more combinations of triangular, rectangular, or shaped steel.

[0012] Furthermore, adjacent upper and lower sections of the hollow steel pipe are fixedly connected by a sleeve, and the connecting end of the hollow steel pipe is inserted into or welded into the sleeve.

[0013] Furthermore, the adjacent upper and lower sections of the hollow steel pipe are fixedly connected by flanges, and the connecting ends of the hollow steel pipes are welded or integrally formed with flanges.

[0014] This invention proposes an innovative composite steel pipe pile structure that uses an open steel pipe with stiffening ribs to replace the traditional concrete pile core. By arranging a rib structure (including annular ribs, fan-shaped ribs, and spiral ribs) on the outer surface of the steel pipe, the friction coefficient at the pile-soil interface is significantly improved; at the same time, an opening is set at the bottom of the steel pipe, allowing soil to enter the pipe cavity during pile driving to form a soil plug, thereby effectively suppressing the soil squeezing effect.

[0015] This invention solves two major technical problems of traditional composite piles: firstly, by utilizing the mechanical interlocking effect between the ribs and the solidified mixture, it overcomes the bearing capacity reduction problem caused by insufficient interlocking at the pile-soil interface; secondly, based on the stress release mechanism of the open cavity, it effectively reduces the soil squeezing effect and significantly improves construction controllability. Engineering practice shows that this structure combines high engineering practicality with ease of construction, providing an efficient and reliable technical solution for foundation pit support and foundation reinforcement projects. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the combined steel pipe pile and its construction method in the embodiments of this utility model.

[0018] Figure 2 This is a cross-sectional view of AA in an embodiment of this utility model.

[0019] Figure 3 This is a schematic diagram of the steel pipe pile with spiral ribs according to the present invention.

[0020] Figure 4 This is a schematic diagram of a steel pipe pile with annular ribs according to the present invention.

[0021] Figure 5 This is a schematic diagram of a steel pipe pile with annular threaded steel bars according to the present invention.

[0022] Figure 6 This is a schematic diagram showing the connection between two hollow steel pipe sections via a sleeve.

[0023] Figure 7 This is a schematic diagram of an annular rib with a ring of through holes.

[0024] Figure 8 This is a schematic diagram of a ring-shaped rib formed by two semi-circular plates.

[0025] Figure 9 This is a schematic diagram of a sleeve used to connect two hollow steel pipe sections.

[0026] Figure 10 This is a schematic diagram showing the connection between two hollow steel pipe sections via a flange. Detailed Implementation

[0027] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0028] To fully understand this utility model, detailed steps and structures will be presented in the following description to illustrate the technical solution of this utility model. Preferred embodiments of this utility model are described in detail below; however, in addition to these detailed descriptions, this utility model may have other embodiments.

[0029] This utility model provides a combined steel pipe pile, in which a steel pipe pile 7 with an opening at the bottom is inserted into a mixing material 5 in a drilled hole to form a combined steel pipe pile 10. The mixing material 5 is a cement-soil pile formed by high-pressure jet grouting or mixing. The admixture of the cement-soil pile is one or more combinations of curing agent, cement, fly ash, etc., to improve the strength after curing.

[0030] The steel pipe pile 7 has one or more hollow steel pipes 1 connected end to end. The outer diameter of the hollow steel pipe 1 is provided with protruding ribs to enhance the bonding force with the mixing material 5. These protruding ribs can be annular ribs 3 installed on the outer diameter of the hollow steel pipe 1 (e.g.,...). Figure 4), fan-shaped ribs and / or spiral ribs 2 (such as Figure 3 ).

[0031] In an optional embodiment, the annular ribs 3 and / or the fan-shaped ribs are circumferentially fixed to the outer diameter of the hollow steel pipe 1 at equal intervals along the axial direction of the steel pipe pile 7.

[0032] In an optional embodiment, the annular rib 3, the fan-shaped rib, and / or the spiral rib 2 are steel plates, which are welded to the outer wall of the hollow steel pipe 1. Through holes can be formed in the thickness direction of the steel plates. After the combined steel pipe pile 10 is placed into the mixing material 5, the mixing material 5 can enter the through holes. After the mixing material 5 solidifies, it can further enhance the bonding force between the combined steel pipe pile 10 and the mixing material 5, thereby improving the overall stability of the combined steel pipe pile 10.

[0033] As an option, the annular rib 3 can be a single piece of annular steel plate (e.g., Figure 7 It can also be composed of two semicircular plates (e.g., Figure 8 ).

[0034] In another alternative embodiment, the annular rib 3, the fan-shaped rib, and / or the spiral rib 2 can be made of threaded steel bars (such as...). Figure 5 The threaded reinforcing bars are connected to the outer wall of the hollow steel pipe 1 by binding or welding. Using threaded reinforcing bars as ribs not only effectively enhances the bonding force with the mixing material 5, but also improves the overall shear strength and tensile strength of the steel pipe pile 7. Furthermore, the use of threaded reinforcing bars increases the friction between the steel pipe pile 7 and the surrounding cement-soil piles, enhancing the stability of the hollow steel pipe 1. The arrangement of the threaded reinforcing bars can also be determined according to actual engineering requirements, with equal or unequal spacing along the axial direction of the steel pipe pile 7 to achieve the best reinforcement effect.

[0035] In an optional embodiment, several reinforcing elbows 4 (such as those for the annular ribs 3, fan-shaped ribs, and / or spiral ribs 2) are welded between the steel pipe pile 7 and the outer wall of the hollow steel pipe 1 on one or both sides of the axial direction. Figure 4 and Figure 6 By reinforcing the elbow plate 4, the connection strength between the annular rib 3, the fan-shaped rib, and / or the spiral rib 2 and the hollow steel pipe 1 can be further enhanced, thereby improving the structural stability and bearing capacity of the entire steel pipe pile 7. The shape and number of reinforcing elbow plates 4 can be designed according to actual engineering needs to ensure the best reinforcement effect.

[0036] In an optional embodiment, adjacent upper and lower hollow steel pipe sections 1 are fixedly connected by a sleeve 8, with the connecting end of the hollow steel pipe 1 inserted into the sleeve 8. The inner wall of the sleeve 8 and the connecting end of the hollow steel pipe 1 can be fastened by welding or threaded connection to ensure the stability and firmness of the connection.

[0037] In an optional embodiment, adjacent upper and lower hollow steel pipe sections 1 are fixedly connected by flanges. The connecting ends of the hollow steel pipe sections 1 are welded or integrally formed with flanges 9. The flanges 9 allow for quick and easy connection of the two hollow steel pipe sections 1, simplifying the installation process and improving the stability and reliability of the connection. Bolt holes can be provided on the flanges 9, and bolts and nuts can be used to tightly connect the adjacent hollow steel pipe sections 1 together, ensuring that the steel pipe pile is not easily loosened when subjected to external forces.

[0038] The implementation steps of this utility model will be further described below with reference to the accompanying drawings and specific embodiments:

[0039] 1) First, ribs are welded at certain intervals along the axial direction of the hollow steel pipe 1 to form the hollow steel pipe 1; the protruding ribs can be... Figure 4 The single circular rib 3 shown can also be formed by welding two semi-circular plates 6 together. Figure 3 The spiral rib 2 is shown. Alternatively, threaded steel bars can be used as the ribs, or steel plates or one or more combinations thereof can be used as the ribs on the outer wall of the hollow steel pipe 1. The ribs can be continuously distributed radially or distributed in a dotted pattern. If the ribs are steel plates, holes can be made in the steel plates, and the annular ribs 3 can be integrally welded to the hollow steel pipe with reinforcing elbow plates 4 on one side or both sides; the reinforcing elbow plates 4 can be triangular, rectangular, or shaped steel or one or more combinations thereof; the spacing or helical pitch of the ribs is specified according to the design.

[0040] 2) Subsequently, cement-soil piles are constructed at the predetermined locations; the cement-soil piles can be high-pressure jet grouting piles or cement-soil mixing piles; the diameter of the cement-soil piles can be increased within a certain height range of the pile bottom; the admixtures of the cement-soil piles can be one or more combinations of curing agents, cement, fly ash, etc.; the amount of admixtures in the cement-soil piles is determined according to the required strength and bearing capacity requirements of the cement-soil piles.

[0041] 3) Subsequently, before the mixture 5 solidifies, steel pipe piles 7 are inserted in sections. The upper and lower sections of steel pipe piles 7 can be connected by welding through sleeves 8, or by bolts through flanges 9. The lower end of the steel pipe pile 7 is open, allowing the mixture of the mixture 5 to enter the steel pipe pile 7 and form a soil plug 11. Ribbed steel pipe piles 7 can be installed in designated strata sections or along the entire length of the pile.

[0042] 4) Then, the entire steel pipe pile 7 is completely inserted into the mixing material 5, and the mixture of the mixing material 5 is completely hardened to form a combined steel pipe pile 10 with the steel pipe pile 7.

[0043] 5) Finally, grouting is performed at the bottom of the composite steel pipe pile 10; whether or not to perform grouting at the bottom of the pile can be determined according to the actual situation.

[0044] The preferred embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above. Devices and structures not described in detail herein should be understood as being implemented in a conventional manner within the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of this utility model using the disclosed methods and techniques, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of this utility model. This does not affect the essential content of this utility model. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model, without departing from the content of the technical solution of this utility model, still fall within the protection scope of the technical solution of this utility model.

Claims

1. A composite steel pipe pile, characterized in that, A steel pipe pile (7) with an opening at the bottom is inserted into a mixing material (5) in a borehole to form a combined steel pipe pile (10). The steel pipe pile (7) has one or more sections of hollow steel pipe (1) connected end to end. The outer diameter of the hollow steel pipe (1) is provided with a rib to enhance the bonding force with the mixing material (5). The rib is an annular rib (3), a fan-shaped rib, and / or a spiral rib (2) installed on the outer diameter of the hollow steel pipe (1).

2. The composite steel pipe pile as described in claim 1, characterized in that, The mixing material (5) is a cement-soil pile formed by high-pressure jet grouting or mixing.

3. A composite steel pipe pile as described in claim 1, characterized in that, The annular ribs (3) and / or the fan-shaped ribs are circumferentially fixed on the outer diameter of the hollow steel pipe (1) at equal or arbitrary intervals along the axial direction of the steel pipe pile (7).

4. A composite steel pipe pile as described in claim 1, characterized in that, The annular rib (3), the fan-shaped rib and / or the spiral rib (2) are steel plates.

5. A composite steel pipe pile as described in claim 4, characterized in that, The annular rib (3), the fan-shaped rib and / or the spiral rib (2) are provided with several through holes in the thickness direction.

6. A composite steel pipe pile as described in claim 1, characterized in that, The annular rib (3), the fan-shaped rib and / or the spiral rib (2) are steel bars.

7. A composite steel pipe pile as described in claim 4, characterized in that, The annular rib is either a one-piece annular steel plate or two semi-circular steel plates.

8. A composite steel pipe pile as described in claim 1, characterized in that, The annular rib (3), the fan-shaped rib and / or the spiral rib (2) are welded with a number of reinforcing elbow plates (4) between the steel pipe pile (7) and the outer wall of the hollow steel pipe (1) on one or both sides of the axial direction. The reinforcing elbow plates (4) are one or more combinations of triangles, rectangles and steel sections.

9. A composite steel pipe pile as described in claim 1, characterized in that, The two adjacent hollow steel pipes (1) are fixedly connected by a sleeve (8), and the connecting end of the hollow steel pipe (1) is inserted into or welded into the sleeve (8).

10. A composite steel pipe pile as described in claim 1, characterized in that, The hollow steel pipes (1) of adjacent upper and lower sections are fixedly connected by flanges, and the ends of the hollow steel pipes (1) are welded or integrally formed with flanges (9).

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