Large-diameter self-expansion steel pipe concrete pile and preparation pile mold and preparation method thereof
By using steel inner pipes in cast-in-place large diameter concrete pipe piles combined with external expanded concrete pipe structural design, the problems of poor load-bearing capacity and bending damage are solved, and efficient load-bearing and stability improvement of the pile body is achieved.
Patent Information
- Application Number
- CN202411833136.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2025-03-14
AI Technical Summary
The load-bearing capacity of cast-in-place large diameter concrete pipe piles is poor and is prone to bending and failure when bearing horizontal loads.
The steel inner pipe is combined with external expanded concrete pipes to apply compressive stress to the outside and internal soil to enhance the load-bearing capacity and bending resistance of the pile body.
It significantly improves the bending and flexural properties of pipe piles, reduces pile body size and material consumption, and improves the friction and stability between pile body and soil.
Smart Images
Figure CN119615883A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of steel tube concrete pile casting, in particular to a large-diameter self-expanding steel tube concrete pile and a pile mold and a preparation method thereof. Background Art
[0002] Traditional pile foundations are mainly solid concrete piles, which have the characteristics of mature construction technology and high bearing capacity. However, solid piles are heavy, have high pile sinking resistance during construction, and are costly. Especially in areas with soft foundations or high groundwater levels, construction difficulties and pile sinking quality problems are prone to occur. Therefore, in order to overcome these problems, engineering technology has gradually developed various new types of pile foundations, including cast-in-place large-diameter concrete pipe piles with hollow structures.
[0003] The advantage of cast-in-place large-diameter concrete pipe piles is that the soil in the center of the pipe pile and the main body of the pipe pile together form the pile foundation structure. The soil in the center of the pipe pile can also effectively participate in the load-bearing, thereby reducing the load component that the pile wall needs to bear. The structural design of this type of pile foundation not only improves the overall load-bearing efficiency of the pile foundation, but also realizes the economical use of pile body materials. However, the pile body of existing cast-in-place large-diameter concrete pipe piles is relatively thin, and its bearing capacity is relatively poor compared to solid piles. In addition, the thin-walled characteristics may cause the pile body to bend and break when subjected to horizontal bending and shear loads. Therefore, how to improve the strength and stiffness of the pile body is the key problem that this technology currently needs to solve.
[0004] Therefore, it is of great significance that the present invention provides a cast-in-place large-diameter self-expanding steel tube concrete pile. Summary of the invention
[0005] In view of the deficiencies in the prior art, the present invention provides a large-diameter self-expanding steel tube concrete pile and a pile mold and a preparation method thereof, which solve the problem that the existing cast-in-place large-diameter concrete tube piles have poor bearing capacity and are easy to bend when subjected to horizontal loads.
[0006] In the first aspect, in order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is:
[0007] A large-diameter self-expanding steel tube concrete pile comprises an expansion concrete tube, an inner tube is arranged inside the expansion concrete tube, and a concrete pile cap is arranged on the top of the expansion concrete tube.
[0008] In this scheme, an inner tube is arranged inside the expansive concrete tube. Different from the existing cast-in-place large-diameter concrete pipe piles, a steel inner tube is combined with an external expansive concrete tube to apply compressive stress to the external and internal soil, thereby enhancing the bearing capacity of the pile body. At the same time, the inner tube supports the expansive concrete tube, thereby improving the bending and shear resistance of the pile body.
[0009] In the second aspect, the present invention provides a preparation pile mold for a large diameter self-expanding steel tube concrete pile based on a large diameter self-expanding steel tube concrete pile provided in the first aspect, which specifically includes: an outer tube and an inner tube, the inner tube is arranged inside the outer tube; a grouting area is between the outer tube and the inner tube; and a valve pile shoe is movably connected to the bottom of the outer tube.
[0010] In this scheme, after the pile form is sunk into the soil, concrete is poured in the grouting area, and the outer tube is pulled out after pouring. During the pulling-out process, the flap pile shoe opens automatically under the action of the gravity of the concrete; after the outer tube is pulled out, concrete continues to be poured in the gap left by the outer tube. Due to the expansion of concrete, a large compressive stress will be applied to the external soil, thereby increasing the friction between the pile and the soil; it will also cause the density of the external soil to increase, thereby increasing the stability between the pile and the soil.
[0011] Furthermore, both the outer tube and the inner tube are steel structures.
[0012] In a third aspect, the present invention provides a method for preparing a large-diameter self-expanding steel tube concrete pile based on a preparation pile mold of a large-diameter self-expanding steel tube concrete pile provided in the second aspect, comprising the following steps:
[0013] S1: sink the outer tube and the inner tube into the soil;
[0014] S2: prepare expansive concrete;
[0015] S3: pour the expansive concrete into the grouting area between the inner tube and the outer tube, and vibrate and compact it;
[0016] S4: Pull out the outer tube, and the flap pile shoe opens during the pulling process;
[0017] S5: Continue pouring expansive concrete in the gap left by the outer tube until the expansive concrete is poured to a preset height, thereby obtaining an expansive concrete tube;
[0018] S6: pour concrete pile cap on top of the expansion concrete pipe and apply static load;
[0019] S7: Wait for the expansion concrete pipe to be hydrated; during the hydration process of the expansion concrete pipe, monitor the vertical displacement of the top of the pile body, and increase or decrease the static load according to the displacement until the vertical displacement of the top of the pile body tends to be stable.
[0020] In this scheme, after pouring expansive concrete in the grouting area, the outer tube is pulled out. Due to the expansiveness of the expansive concrete, the friction between the pile and the soil is increased, thereby improving the stability of the pile foundation. The inner tube is retained. The inner tube generates restraining stress on the internal soil and restricts the expansive concrete, thereby avoiding the obvious necking and squeezing effect of the internal soil due to the expansiveness of the expansive concrete, thereby avoiding the problem of the pile floating.
[0021] Furthermore, when the outer pipe and the inner pipe are sunk in S1, if the soil is clayey, static pressure construction is adopted; if the soil is sandy, tamping or vibration construction is adopted.
[0022] In this solution, the pile form sinking method is selected according to the geology of the soil to ensure that the inner tube fits tightly with the soil inside it.
[0023] Furthermore, when preparing the expansive concrete in S2, cement, gravel, sand, water, high-performance expansive agent and water reducing agent are uniformly mixed in a ratio of 1:2:1:0.25:0.2:0.01 to obtain the expansive concrete.
[0024] In this solution, a high-performance expansive agent is added to the expansive concrete to ensure that the poured expansive concrete is in close contact with the external soil, thereby improving the stability of the pile.
[0025] Furthermore, before pouring the expansive concrete in S3, a steel cage is placed in the grouting area.
[0026] In this scheme, for piles that need to resist bending and folding, a steel cage is placed during pouring to enhance the bending and folding resistance of the pile.
[0027] The beneficial effects of the present invention are:
[0028] The large-diameter self-expanding steel tube concrete pile provided by the present invention is different from the traditional steel tube concrete structure which adopts the form of internal expansion concrete combined with external steel tube. Instead, it adopts the form of steel inner tube combined with external expansion concrete tube, which can simultaneously apply compressive stress to the external and internal soil bodies; ensure the stability and bearing capacity of the pile body, and can significantly improve the bending and folding resistance of the pile. Compared with the existing concrete piles, the required pile body size and material consumption are significantly lower than the existing cast-in-place large-diameter concrete pipe piles, and much lower than the solid single piles.
[0029] In the preparation method of large-diameter self-expanding steel tube concrete piles, the outer tube is pulled out after pouring the expansive concrete. Due to the expansiveness of the expansive concrete, a large compressive stress is applied to the external soil, thereby increasing the friction between the pile and the soil; it also causes the density of the external soil to increase, thereby increasing the friction coefficient between the pile and the soil; the inner tube is retained. While the inner tube generates restraining stress on the internal soil, the restriction of the inner tube also avoids the obvious necking and soil squeezing effect of the internal soil after the expansion of the expansive concrete, thereby avoiding the floating of the pile and causing the pile to be unstable. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 This is a schematic structural diagram of a large-diameter self-expanding steel tube concrete pile in Example 1;
[0031] Figure 2This is a schematic structural diagram of a pile mold for preparing a large-diameter self-expanding steel tube concrete pile in Example 2;
[0032] Figure 3 This is a schematic structural diagram of a pile mold for preparing a large-diameter self-expanding steel tube concrete pile in Example 2;
[0033] Figure 4 This is a schematic diagram of the structure of the pile form being sunk into the soil in Example 3;
[0034] Figure 5 It is a schematic diagram of the structure of pouring concrete into the grouting area in Example 3;
[0035] Figure 6 This is a schematic diagram of the structure after the outer tube is pulled out in Example 3.
[0036] Reference numerals:
[0037] 1. Outer pipe; 2. Inner pipe; 3. Expansive concrete pipe; 4. Concrete pile cap; 5. Valve pile shoe; 6. Expansive concrete; 7. Grouting area; 8. Conical platform; DETAILED DESCRIPTION
[0038] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. The specific implementation of the present invention is described below to facilitate the understanding of the present invention by those skilled in the art, but it should be clear that the present invention is not limited to the scope of the specific implementation. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.
[0039] Example 1
[0040] like Figure 1 As shown, this embodiment provides a large-diameter self-expanding steel tube concrete pile, which adopts a steel inner tube combined with an expansive concrete tube to ensure the stability and bearing capacity of the pile body and significantly improve the bending and folding resistance of the pile; it specifically includes:
[0041] Inner pipe 2, expansion concrete pipe 3 and concrete pile cap 4;
[0042] Among them, an inner tube 2 is arranged inside the expansive concrete tube 3, and the inner tube 2 supports the expansive concrete tube 3 to ensure the stability and bearing capacity of the pile body and improve the bending and shear resistance of the pile body; a concrete pile cap 4 is arranged on the top of the expansive concrete tube 3.
[0043] Example 2
[0044] Based on a large-diameter self-expanding steel tube concrete pile provided in Example 1, this embodiment provides a preparation pile mold for a large-diameter self-expanding steel tube concrete pile, which specifically includes: an outer tube 1 and an inner tube 2, wherein the inner tube 2 is arranged inside the outer tube 1; a grouting and pouring area 7 is provided between the outer tube 1 and the inner tube 2; and a flap pile shoe 5 is movably connected at the bottom of the outer tube 1. After the pile mold is sunk into the soil, concrete is poured in the grouting and pouring area 7, and the outer tube 1 is pulled out after pouring. During the pulling-out process, the flap pile shoe 5 automatically opens under the gravity of the concrete; after the outer tube 1 is pulled out, concrete is continuously poured in the gap left by the outer tube 1. Due to the expansion of the concrete, a large compressive stress will be applied to the external soil, thereby increasing the friction between the pile body and the soil; it will also promote the increase of the density of the external soil, thereby increasing the stability between the pile body and the soil.
[0045] The outer tube 1 and the inner tube 2 are both steel structures.
[0046] As another implementation of this embodiment, a conical platform 8 is provided at the bottom of the inner tube 2, and the valve shoe 5 is not required at the bottom of the outer tube 1, and the outer tube 1 is directly seated on the conical platform 8; Figure 3 shown.
[0047] Example 3
[0048] This embodiment provides a preparation method of a large-diameter self-expanding steel tube concrete pile based on a preparation pile mold of a large-diameter self-expanding steel tube concrete pile provided in Embodiment 2, comprising the following steps:
[0049] S1: Sink the outer tube 1 and the inner tube 2 into the soil. Figure 4 As shown;
[0050] If the soil is clay, static pressure construction is adopted; if the soil is sandy, tamping or vibration construction is adopted.
[0051] S2: prepare expansive concrete 6;
[0052] Cement, gravel, sand, water, high-performance expansive agent and water reducing agent are uniformly mixed according to the ratio of 1:2:1:0.25:0.2:0.01 to obtain expansive concrete 6; the high-performance expansive agent can enhance the expansibility of the expansive concrete 6, ensure that the poured expansive concrete 6 is in close contact with the external soil, and improve the stability of the pile body.
[0053] S3: Pour the expansive concrete 6 into the grouting area 7 between the inner tube 2 and the outer tube 1, and vibrate and compact it. Figure 5 As shown;
[0054] For piles that need to resist bending and folding, adding steel cages during pouring can enhance the pile's resistance to bending and folding.
[0055] S4: Pull out the outer tube 1. During the pulling-out process, the flap pile shoe 5 opens under the gravity of the expansive concrete 6.
[0056] S5: Figure 6 As shown, the expansive concrete 6 is continuously poured in the space left by the outer tube 1 until the expansive concrete 6 is poured to a preset height, thereby obtaining the expansive concrete tube 3 .
[0057] S6: pouring a concrete pile cap 4 on the top of the expansion concrete pipe 3 and applying a static load;
[0058] S7: Waiting for the expansion concrete tube 3 to be hydrated; during the hydration process of the expansion concrete tube 3, monitoring the vertical displacement of the top of the pile body, and increasing or decreasing the static load according to the displacement, until the vertical displacement of the top of the pile body tends to be stable.
[0059] In this embodiment, after pouring the expansive concrete 6 in the grouting area 7, the outer tube 1 is pulled out. Due to the expansibility of the expansive concrete 6, the friction between the pile body and the soil body is increased, thereby improving the stability of the pile foundation. The inner tube 2 is retained. The inner tube 2 generates a restraining stress on the internal soil body and restricts the expansive concrete 6, thereby avoiding the obvious necking and squeezing effect of the internal soil body due to the expansibility of the expansive concrete 6, thereby avoiding the problem of the pile body floating.
[0060] Those skilled in the art will appreciate that the embodiments herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the invention.
Claims
1. A large diameter self-expanding steel tube concrete pile, characterized in that: It comprises an expansion concrete pipe (3), wherein an inner pipe (2) is arranged on the inner side of the expansion concrete pipe (3); and a concrete pile cap (4) is arranged on the top of the expansion concrete pipe (3).
2. A pile mold for preparing a large-diameter self-expanding steel tube concrete pile according to claim 1, characterized in that: It comprises an outer tube (1) and an inner tube (2), wherein the inner tube (2) is arranged inside the outer tube (1); a grouting area (7) is provided between the outer tube (1) and the inner tube (2); and a valve pile shoe (5) is movably connected to the bottom of the outer tube (1).
3. The preparation pile mold for large-diameter self-expanding steel tube concrete pile according to claim 2 is characterized in that: The outer tube (1) and the inner tube (2) are both steel structures.
4. A method for preparing a large-diameter self-expanding steel tube concrete pile according to claim 3, characterized in that: The following steps are involved: S1: sinking the outer tube (1) and the inner tube (2) into the soil; S2: preparing expansive concrete (6); S3: pouring the expansive concrete (6) into the grouting area (7) between the inner tube (2) and the outer tube (1), and vibrating and compacting the concrete; S4: Pull out the outer tube (1), and during the pulling out process, the flap pile shoe (5) opens; S5: Continue pouring the expansive concrete (6) in the gap left by the outer tube (1) until the expansive concrete (6) is poured to a preset height, thereby obtaining an expansive concrete tube (3); S6: pouring a concrete pile cap (4) on the top of the expansion concrete pipe (3) and applying a static load; S7: Waiting for the expansion concrete pipe (3) to be hydrated; during the hydration process of the expansion concrete pipe (3), monitoring the vertical displacement of the top of the pile body, and increasing or decreasing the static load according to the displacement, until the vertical displacement of the top of the pile body tends to be stable.
5. The method for preparing a large-diameter self-expanding steel tube concrete pile according to claim 4, characterized in that: When the outer tube (1) and the inner tube (2) are sunk into the S1, if the soil is clayey, static pressure construction is adopted; if the soil is sandy, tamping or vibration construction is adopted.
6. The method for preparing a large-diameter self-expanding steel tube concrete pile according to claim 4, characterized in that: When preparing the expansive concrete (6) in S2, cement, gravel, sand, water, high-performance expansive agent and water reducing agent are uniformly mixed according to the ratio of 1:2:1:0.25:0.2:0.01 to obtain the expansive concrete (6).
7. The method for preparing a large-diameter self-expanding steel tube concrete pile according to claim 4, characterized in that: Before pouring the expansive concrete (6) in S3, a steel cage is placed in the grouting area (7).