Steel pipe screw pile

Abstract

The utility model provides a steel pipe screw pile. The steel pipe screw pile comprises a steel pipe; the spiral blades surround the steel pipe and are fixedly connected with the steel pipe; the annular three-fork support is fixedly connected with the top of the steel pipe, and the diameter of the three-fork support is larger than that of the spiral blade. According to the scheme, the problem that the horizontal bearing capacity is low after the steel pipe screw pile is formed can be solved, and the horizontal bearing capacity of the steel pipe screw pile is obviously improved.

Description

Technical Field

[0001] This utility model relates to the field of civil engineering technology, and in particular to a steel pipe helical pile. Background Technology

[0002] Steel pipe helical piles are the most widely used type of helical pile, and this pile type has become a very mature type. Due to their advantages such as fast construction speed, minimal environmental damage, and simple operation, steel pipe helical piles have been successfully applied in industries such as transportation, power, and building alignment correction.

[0003] However, the existing steel pipe helical piles, after pile driving, exhibit significantly lower horizontal bearing capacity, failing to meet the structural design requirements. This problem arises because during pile driving, the blades disturb the surrounding soil, causing structural damage, particularly to the shallow soil layers. This damage has the greatest impact on horizontal bearing capacity, as it primarily depends on the soil properties within a depth of 2(d+1) (d being the pile diameter) below the pile top. Since the blade diameter of the steel pipe helical pile is larger than the pile diameter, it cuts through the soil during driving, disrupting the surrounding soil structure and thus significantly reducing the horizontal bearing capacity.

[0004] In the current application of steel pipe helical piles, the focus is on the vertical compressive and tensile bearing capacity of the pile foundation, while less research is done on the horizontal bearing capacity, which limits its further development in various industries. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a steel pipe spiral pile that can solve the problem of low horizontal bearing capacity after the steel pipe spiral pile is formed, and significantly improve the horizontal bearing capacity of the steel pipe spiral pile.

[0006] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0007] A steel pipe helical pile, comprising:

[0008] steel pipe;

[0009] Multiple helical blades surround the steel pipe, and the helical blades are fixedly connected to the steel pipe;

[0010] A circular three-pronged bracket is fixedly connected to the top of the steel pipe, the diameter of which is larger than the diameter of the helical blade.

[0011] Optionally, the steel pipe includes a cylindrical steel pipe body and a conical tip fixedly connected to the cylindrical steel pipe body.

[0012] Optionally, the diameter of the main body of the steel pipe is equal to the diameter of the bottom surface of the conical tip.

[0013] Optionally, the plurality of helical blades are arranged at equal intervals around the surface of the steel pipe at a certain preset distance.

[0014] Optionally, the tripod support includes:

[0015] A cylindrical inner ring with a predetermined height;

[0016] Cylindrical outer ring;

[0017] Multiple blades are fixedly connected to the cylindrical inner ring and the cylindrical outer ring.

[0018] Optionally, the diameter of the cylindrical inner ring is equal to the diameter of the steel pipe body.

[0019] Optionally, the height of the inner cylindrical ring is equal to the height of the outer cylindrical ring.

[0020] Optionally, the diameter of the cylindrical outer ring is twice the diameter of the helical blade.

[0021] Optionally, the heights of the cylindrical inner ring and the cylindrical outer ring are within a first preset range.

[0022] Optionally, the cylindrical inner ring of the three-pronged bracket is clamped to the top of the steel pipe.

[0023] The above-described solution of this utility model has at least the following beneficial effects:

[0024] The above-mentioned solution of this utility model uses a steel pipe; multiple spiral blades surrounding the steel pipe, the spiral blades being fixedly connected to the steel pipe; and a circular three-pronged bracket fixedly connected to the top of the steel pipe, the diameter of the three-pronged bracket being larger than the diameter of the spiral blades, to solve the problem of low horizontal bearing capacity after the steel pipe spiral pile is formed, thus significantly improving the horizontal bearing capacity of the steel pipe spiral pile. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a steel pipe helical pile provided in an embodiment of this utility model;

[0026] Figure 2 This is a schematic diagram of the steel pipe and spiral blade provided in an embodiment of this utility model;

[0027] Figure 3 This is a schematic diagram of a three-pronged bracket provided in an embodiment of this utility model;

[0028] Explanation of reference numerals in the attached figures:

[0029] 1. Steel pipe; 2. Spiral blade; 31. Cylindrical inner ring; 32. Cylindrical outer ring; 33. Blade. Detailed Implementation

[0030] Exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0031] like Figure 1 As shown, an embodiment of this utility model proposes a steel pipe helical pile, comprising:

[0032] Steel pipe 1;

[0033] Multiple helical blades 2 surround the steel pipe 1, and the helical blades 2 are fixedly connected to the steel pipe 1;

[0034] A circular three-pronged bracket is fixedly connected to the top of the steel pipe 1, and the diameter of the three-pronged bracket is larger than the diameter of the spiral blade 2.

[0035] In this embodiment, the steel pipe helical pile includes a steel pipe 1 surrounded by helical blades 2, and a three-pronged support fixed to the top of the steel pipe 1. During construction, the steel pipe 1 extends into the soil. Due to the multiple evenly distributed helical blades 2 surrounding its surface, it has high load-bearing capacity and stability. Under load, it can evenly distribute stress, thus providing good support. The three-pronged support is an annular ring with a diameter significantly larger than that of the helical blades 2, and it is fixed to the top of the steel pipe 1. After the steel pipe 1 is driven into the soil, the three-pronged support is aligned with the insertion port at the top of the steel pipe 1 by insertion and extraction, and pressed into the soil through the insertion port, so that the steel pipe 1, the three-pronged support, and the soil form a whole.

[0036] The three-pronged support increases the contact area between the top of the steel pipe helical pile and the soil, thereby strengthening the constraint of the shallow soil, improving the stiffness of the shallow pile, and enhancing the horizontal bearing capacity of the steel pipe helical pile.

[0037] In an optional embodiment of this utility model, the steel pipe 1 includes a cylindrical steel pipe body and a conical tip fixedly connected to the cylindrical steel pipe body. The diameter of the steel pipe body is equal to the diameter of the base of the conical tip.

[0038] In this embodiment, the bottom of the steel pipe 1 is provided with a conical tip, which allows the steel pipe 1 to sink into the soil more effectively. The main body of the steel pipe 1 is a slender cylinder, which increases the stability of the steel pipe helical pile after pile formation.

[0039] like Figure 2As shown, in an optional embodiment of the present invention, the plurality of spiral blades 2 are arranged at equal intervals around the surface of the steel pipe 1 at a certain preset distance.

[0040] In this embodiment, multiple helical blades 2 are provided on the surface of the steel pipe 1. During the pile driving process of the steel pipe 1, the helical blades 2 cut the soil, causing disturbance to the soil around the pile. Preferably, the helical blades 2 are welded and fixed to the steel pipe 1.

[0041] like Figure 3 As shown, in an optional embodiment of this utility model, the three-pronged support includes:

[0042] A cylindrical inner ring 31 with a predetermined height;

[0043] Cylindrical outer ring 32;

[0044] Multiple blades 33 are fixedly connected to the cylindrical inner ring 31 and the cylindrical outer ring 32.

[0045] In this embodiment, the inner cylindrical ring 31 and the outer cylindrical ring 32 are two concentric circles, and the blades 33 are disposed on the radius of the outer cylindrical ring 32. Preferably, three blades 33 are provided, with an included angle of 120° between the three blades 33, and they are evenly arranged around the inner cylindrical ring 31, fixing the outer cylindrical ring 32 and the inner cylindrical ring 31 together. The three-pronged bracket can increase the horizontal bearing capacity of the steel pipe helical pile.

[0046] In an optional embodiment of this utility model, the diameter of the cylindrical inner ring 31 is equal to the diameter of the steel pipe body.

[0047] The cylindrical inner ring 31 is fixed to the top of the steel pipe body by insertion and removal, thus fixing the three-pronged bracket and the steel pipe 1 together.

[0048] In an optional embodiment of this utility model, the height of the cylindrical inner ring 31 is equal to the height of the cylindrical outer ring 32, and the heights of the cylindrical inner ring 31 and the cylindrical outer ring 32 are within a first preset range. Preferably, the first preset range is 10-15cm.

[0049] In an optional embodiment of this utility model, the diameter of the cylindrical outer ring 32 is twice the diameter of the helical blade 2.

[0050] In this embodiment, the diameter of the cylindrical outer ring 32 is twice the diameter of the spiral blade 2. Due to the transmission effect of the three-pronged support, the horizontal force around the pile is transmitted to the original soil outside the disturbed soil through the three-pronged support. By increasing the force-bearing area of ​​the horizontal force at the pile top, the horizontal bearing capacity is improved.

[0051] In an optional embodiment of this utility model, the cylindrical inner ring 31 of the three-pronged bracket is clamped to the top of the steel pipe 1.

[0052] The principle behind the three-pronged bracket enhancing the horizontal bearing capacity of the steel pipe helical pile in the above embodiments of this utility model is as follows:

[0053] 1. Trident support enhances the confinement of shallow soil.

[0054] The three-pronged support increases the pile diameter, with the equivalent diameter increasing from the diameter of the pile's spiral blades to the outer diameter of the three-pronged support, specifically the diameter of the cylindrical outer ring (32mm). This increases the passive earth pressure.

[0055] The formula for passive earth pressure is:

[0056]

[0057] Among them, P p γ represents passive earth pressure, and γ represents the soil unit weight, in kN / m. 3 z represents the depth of the calculation point, and Kp represents the passive earth pressure coefficient.

[0058] The formula for the total passive earth pressure distributed along the pile is:

[0059]

[0060] Among them, P p总 L is the total passive earth pressure, L is the effective load depth of the pile, and D is the width of the pile-soil contact surface.

[0061] Through the above expression, D is increased from the diameter of the pile's helical blades to the outer diameter of the three-pronged support, which increases the total passive earth pressure. The greater the passive earth pressure, the stronger the lateral support of the soil on the pile, and the higher the horizontal bearing capacity of the pile.

[0062] 2. Bending stiffness EI of the three-pronged support reinforced pile

[0063] EI = E·I E

[0064] Where EI is the bending stiffness of the pile, E is the elastic modulus of the material (in kPa or GPa), and I is the moment of inertia of the pile section, reflecting the contribution of the cross-sectional shape to the bending stiffness (in meters). 4 .

[0065] Let the bending stiffness of the steel pipe helical pile with a three-pronged support be EI. 总 E1 and E2 are the elastic moduli of the three-pronged support and the steel pipe, respectively. Then:

[0066] EI 总 =E1·I 三叉支架 +E2·I钢管

[0067] The higher the EI, the higher the stiffness of the pile and the smaller the deformation. Under horizontal load, the pile will undergo bending deformation. The pile with high stiffness has small deformation and can therefore withstand greater loads without exceeding the allowable deformation. This device improves the bending stiffness of the pile, thereby improving the horizontal bearing capacity of the pile.

[0068] The above embodiments of this utility model increase passive earth pressure by increasing pile diameter and improving soil compaction, thereby enhancing bearing capacity and shallow soil constraint. The construction process is simple to operate, possessing operability and large-scale promotion potential, and is easily mass-produced. It has high practical value, significantly improving horizontal bearing capacity, thus greatly saving project costs, shortening construction time, and resulting in significant economic benefits.

[0069] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A steel pipe helical pile, characterized in that, include: Steel pipe (1); Multiple helical blades (2) surround the steel pipe (1), and the helical blades (2) are fixedly connected to the steel pipe (1); A circular three-pronged bracket is fixedly connected to the top of the steel pipe (1), the diameter of which is larger than the diameter of the spiral blade (2).

2. The steel pipe spiral pile according to claim 1, characterized in that, The steel pipe (1) includes a cylindrical steel pipe body and a conical tip fixedly connected to the cylindrical steel pipe body.

3. The steel pipe spiral pile according to claim 2, characterized in that, The diameter of the main body of the steel pipe is equal to the diameter of the bottom surface of the conical tip.

4. The steel pipe spiral pile according to claim 1, characterized in that, The plurality of spiral blades (2) are arranged at equal intervals around the surface of the steel pipe (1) at a certain preset distance.

5. The steel pipe spiral pile according to claim 2, characterized in that, The tripod support includes: A cylindrical inner ring (31) with a certain preset height; Cylindrical outer ring (32); Multiple blades (33) are fixedly connected to the cylindrical inner ring (31) and the cylindrical outer ring (32).

6. The steel pipe spiral pile according to claim 5, characterized in that, The diameter of the cylindrical inner ring (31) is equal to the diameter of the main body of the steel pipe.

7. The steel pipe helical pile according to claim 5, characterized in that, The height of the cylindrical inner ring (31) is equal to the height of the cylindrical outer ring (32).

8. The steel pipe spiral pile according to claim 5, characterized in that, The diameter of the cylindrical outer ring (32) is twice the diameter of the helical blade (2).

9. The steel pipe spiral pile according to claim 5, characterized in that, The heights of the cylindrical inner ring (31) and the cylindrical outer ring (32) are within a first preset range.

10. The steel pipe helical pile according to claim 5, characterized in that, The cylindrical inner ring (31) of the three-pronged bracket is clamped to the top of the steel pipe (1).

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