A prefabricated pipe pile capable of improving the vertical bearing capacity of the pile bottom

Abstract

The present invention provides a prefabricated pipe pile capable of improving the vertical bearing capacity of the pile bottom, comprising a hollow pile body, wherein the inner diameter of the upper portion of the pile body is uniform, and the inner diameter of the lower portion of the pile body gradually decreases from a height above the pile bottom to the pile bottom. The present invention improves the vertical bearing capacity of the prefabricated pipe pile bottom by increasing the concrete load-bearing area at the prefabricated pipe pile bottom. Specifically, when making the prefabricated pipe pile, the upper portion is kept unchanged from the existing prefabricated pipe pile, and the concrete portion is gradually increased from a distance h from the prefabricated pipe pile bottom to the pile bottom. The resulting prefabricated pipe pile has a thickness t greater than that of the conventional prefabricated pipe pile bottom concrete, and the concrete load-bearing area at the prefabricated pipe pile bottom is also increased accordingly, thereby improving the vertical bearing capacity of the prefabricated pipe pile bottom.

Description

Technical Field

[0001] The present invention relates to the field of bridge construction, and in particular to a prefabricated pipe pile capable of improving the vertical bearing capacity of a pile bottom. Background Art

[0002] Bridges are irreplaceable in people's transportation lives. They facilitate daily life and solve transportation problems across waterways and valleys, playing an important role. Piles, as part of a bridge, bear the bridge's vertical bearing capacity. Therefore, the vertical bearing capacity of the piles determines the bridge's vertical bearing capacity. In recent years, the promotion of prefabricated structures has significantly increased the construction speed of bridges and other projects, and prefabricated components have also been widely used. Prefabricated pipe piles are frequently used in bridge construction due to their simple construction, short construction period, low technical difficulty, high environmental benefits, and the ability to significantly reduce costs and save steel. Currently used prefabricated pipe piles often have a fixed inner diameter along the length of the pile, resulting in a small load-bearing area for the concrete at the pile bottom and a low vertical bearing capacity. The vertical bearing capacity of prefabricated pipe piles determines the vertical bearing capacity of prefabricated bridges. Therefore, improving the vertical bearing capacity of prefabricated pipe piles is essential. Summary of the Invention

[0003] Based on the above content, it is necessary to provide a prefabricated pipe pile that can improve the vertical bearing capacity of the pile bottom, so as to solve the problem of low vertical bearing capacity of the pile bottom of the previous prefabricated pipe piles.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A prefabricated pipe pile capable of improving the vertical bearing capacity of the pile bottom comprises a hollow pile body, wherein the inner diameter of the upper portion of the pile body is the same, and the inner diameter of the lower portion of the pile body gradually decreases from a height h from the pile bottom to the pile bottom, wherein the range of h is Wherein, F is the vertical bearing capacity of the precast pipe pile, τ is the design allowable shear stress of the pile concrete material, D1 is the outer diameter of the pile body, D2 is the inner diameter of the portion of the pile body where the height from the pile bottom is greater than h, and t is the thickness difference between the pile body and the pile bottom, which is the difference between the thickness of the pile body at the bottom and the thickness of the portion of the pile body where the height from the pile bottom is greater than h.

[0006] Furthermore, the range of the thickness difference t of the pile body and the pile bottom is Where [σ] is the allowable compressive stress of the pile concrete material, d 管 The diameter of the lower pipe should be reserved for the bottom of the pile.

[0007] Compared with the prior art, the present invention has the following beneficial effects:

[0008] 1. The prefabricated pipe piles proposed in the present invention can improve the vertical bearing capacity of the bottom of the prefabricated pipe piles compared with the existing prefabricated pipe piles. Specifically, the vertical bearing capacity of the bottom of the prefabricated pipe piles is improved by increasing the load-bearing area of ​​the concrete at the bottom of the prefabricated pipe piles and increasing the thickness of the concrete at the bottom of the pile body.

[0009] 2. The present invention can be applied to prefabricated pipe piles of various diameters, and has convenient construction, simple structure, and convenient operation, and has high promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a longitudinal cross-sectional view of the present invention.

[0011] Figure 2 yes Figure 1 Transverse cross-section at point 1-1.

[0012] Figure 3 yes Figure 1 Transverse cross-section at 2-2.

[0013] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0014] See also Figure 1-3 In a preferred embodiment of the present invention, a prefabricated pipe pile capable of improving the vertical bearing capacity of the pile bottom comprises a hollow pile body, wherein the inner diameter of the upper portion of the pile body is the same, and the inner diameter of the lower portion of the pile body gradually decreases from a height h from the pile bottom to the pile bottom, and the range of h is Where F is the vertical bearing capacity of the prefabricated pipe pile, τ is the design allowable shear stress of the pile concrete material, D1 is the outer diameter of the pile body, D2 is the inner diameter of the portion of the pile body that is greater than h from the pile bottom, and t is the thickness difference of the pile body at the bottom, which is the difference between the thickness of the pile body at the bottom and the thickness of the portion of the pile body that is greater than h from the pile bottom. Furthermore, the range of the thickness difference t of the pile body at the bottom is Where [σ] is the allowable compressive stress of the pile concrete material, d 管 The diameter of the lower pipe should be reserved for the bottom of the pile.

[0015] The present invention increases the stress-bearing area of ​​the concrete at the bottom of the prefabricated pipe pile, thereby improving the vertical bearing capacity of the bottom of the prefabricated pipe pile. That is, when making the prefabricated pipe pile, the upper part is kept unchanged from the existing prefabricated pipe pile, and the concrete part is gradually increased from a distance h from the bottom of the prefabricated pipe pile to the bottom of the pipe pile. The thickness of the concrete at the bottom of the obtained prefabricated pipe pile is increased by t compared with the previous prefabricated pipe pile, and the stress-bearing area of ​​the concrete at the bottom of the prefabricated pipe pile is also increased accordingly, thereby improving the vertical bearing capacity of the bottom of the prefabricated pipe pile.

[0016] For the prefabricated pipe piles of the present invention, the value ranges of h and t are determined by the following method.

[0017] The first step is to determine the thickness difference t of the pile body and pile bottom:

[0018] ① Assuming that the bottom should leave a diameter d for the lower tube 管 In order to facilitate the pouring of concrete into the lower pipe, d≥d 管 , where d is the inner diameter of the prefabricated pipe pile bottom, and d = D2-2t, so,

[0019] ② Assuming that the vertical bearing capacity of precast pipe pile is F, since the allowable compressive stress [σ] of concrete needs to be considered, we have Where A is the compressive area of ​​concrete, Therefore, Thus, it can be deduced that

[0020] In summary, the value range of t is

[0021] The second is to determine the value range of h (also known as the height of the increase in the thickness of the prefabricated pipe pile):

[0022] In order to prevent the extra concrete thickness at the bottom from being sheared, Where A' is the area subjected to shear force, F' is the force borne by the extra thickness t of concrete at the bottom of the pile. It follows from this That is the value range of h.

[0023] The manufacturing process of the prefabricated pipe pile designed by the present invention is as follows:

[0024] Step 1: Determine the inner and outer diameters of the prefabricated pipe piles, i.e., the sizes of D1 and D2, according to the connection between the prefabricated pipe pile installation platform and the prefabricated pipe piles.

[0025] Step 2: Based on the known maximum vertical bearing capacity F required for the bridge and the diameter d of the concrete pipe (lower pipe) used 管 , add the inner and outer diameters of the prefabricated pipe pile in step 1, and enter the formula of thickness difference t to calculate the value range of thickness difference t required for thickening the pile body and pile bottom, and then select the appropriate t value.

[0026] Step 3: Based on the thickness difference t of the pile body and the pile bottom, the range of values ​​of the height h of the prefabricated pipe pile thickness increase is obtained after substituting it into the above calculation, and then the appropriate h value is selected.

[0027] Step 4: Create a mold for the precast pile based on the inner and outer diameters, the thickness difference (t) of the pile base, and the height (h) of the added thickness. Starting from the distance h from the pile base, gradually reduce the inner diameter inward until the base reaches D2-2t, while the upper portion remains the same as the original precast pile.

[0028] Step 5: After the mold is made, place the steel cage into the mold, insert the lower pipe into the inside of the mold until the bottom of the pile, pour in concrete, and the production is completed after it dries.

[0029] The above description is a detailed description of the preferred embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. Any equivalent changes or modifications completed under the technical spirit suggested by the present invention should fall within the patent scope covered by the present invention.

Claims

1. A prefabricated pipe pile capable of improving the vertical bearing capacity of the pile bottom, comprising a hollow pile body, characterized in that: The inner diameter of the upper part of the pile body is the same, and the inner diameter of the lower part of the pile body gradually decreases from the height h from the pile bottom to the pile bottom, and the range of h is Where F is the vertical bearing capacity of the prefabricated pipe pile, τ is the design allowable shear stress of the pile concrete material, D1 is the outer diameter of the pile body, D2 is the inner diameter of the part of the pile body with a height greater than h from the pile bottom, and t is the thickness difference of the pile body at the bottom, which is the difference between the thickness of the pile body at the bottom and the thickness of the part of the pile body with a height greater than h from the pile bottom; the range of the thickness difference t of the pile body at the bottom is Where [σ] is the allowable compressive stress of the pile concrete material, d 管 The diameter of the lower pipe should be reserved for the bottom of the pile.

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