Method for determining disc spacing of double disc extrusion expansion branch disc pile

Abstract

This invention generally relates to the field of expanded-diaphragm pile technology, and in particular to a method for determining the spacing between the discs of a double-disc expanded-diaphragm pile. The method includes: obtaining the physical parameters of the target soil and the double-disc expanded-diaphragm pile, including the soil's lateral pressure coefficient, unit weight, internal friction angle, cohesion, the depth of the upper disc, the disc diameter, and the pile diameter; calculating the ultimate bearing capacity of the target soil based on the cohesion, internal friction angle, unit weight, depth of the upper disc, disc diameter, lateral pressure coefficient, and pile diameter; calculating the projected area of ​​the upper disc based on the disc diameter and pile diameter; further calculating the bearing capacity of the upper disc; and finally calculating the optimal disc spacing based on the upper disc bearing capacity and the physical parameters of the target soil and the double-disc expanded-diaphragm pile. This invention not only has a simple calculation process, but the calculated optimal disc spacing can significantly improve the bearing capacity of the expanded-diaphragm pile, and has high practical value in engineering.

Description

Technical Field

[0001] This invention generally relates to the field of extrusion-expanded support pile technology, and in particular to a method for determining the spacing between the discs of a double-disc extrusion-expanded support pile. Background Technology

[0002] Disc piles are a type of pile proposed by Indian scholars in the 1950s and introduced to my country in the 1990s, where they have been further developed. These piles are variable cross-section piles created by rotating or compressing a disc at different soil depths to enlarge the disc diameter, followed by the pouring of concrete, based on the principle of constant-diameter piles. Due to their high bearing capacity and settlement control effect, they have gradually been applied to highway engineering in soft soil areas of my country.

[0003] Multiple studies have shown that the spacing between the discs is one of the main factors affecting the bearing capacity of double-disc expanded-diameter piles. When the disc spacing is small, the bearing capacity of the upper disc cannot be fully utilized, while when the disc spacing is too large, the "time effect" of the bearing capacity of the upper and lower discs is obvious, leading to asynchronous development of bearing capacity. Both of these situations will reduce the bearing capacity of the pile. Therefore, a reasonable disc spacing can maximize the bearing capacity and fully utilize the bearing efficiency of the pile.

[0004] Currently, the optimal disc spacing for double-disc expanded bearing piles is determined by obtaining the ultimate bearing capacity of the piles with different disc spacings through indoor model tests, field tests, or finite element simulations. The disc spacing corresponding to the maximum ultimate bearing capacity is considered the optimal disc spacing. It can be seen that the existing process for determining the optimal disc spacing is cumbersome and inefficient. Summary of the Invention

[0005] This invention provides a method for determining the spacing between the discs of a double-disc expanded support pile, which is used to solve the above-mentioned problem.

[0006] According to one aspect of the present invention, a method for determining the spacing between the discs of a double-disc expanded-support pile is provided, wherein the method includes:

[0007] Obtain the physical parameters of the target soil and the double-disc extrusion pile. The physical parameters of the target soil include the lateral pressure coefficient, unit weight, internal friction angle, and cohesion. The physical parameters of the double-disc extrusion pile include the embedment depth of the upper disc, the disc diameter, and the pile diameter.

[0008] The ultimate bearing capacity of the target soil is calculated based on cohesion, internal friction angle, unit weight of soil, depth of the upper plate, diameter of the plate, lateral pressure coefficient of soil, and pile diameter.

[0009] The projected area of ​​the upper plate is calculated based on the diameter of the plate and the diameter of the pile.

[0010] The bearing capacity of the hanging wall is calculated based on the ultimate bearing capacity of the target soil and the projected area of ​​the hanging wall; the bearing capacity of the hanging wall is positively correlated with the ultimate bearing capacity of the target soil and the projected area of ​​the hanging wall.

[0011] Based on the bearing capacity of the upper plate, combined with the plate diameter, the burial depth of the upper plate, the unit weight of the soil, the internal friction angle, the lateral pressure coefficient of the soil, and the cohesion, the plate spacing is calculated, and this plate spacing is the optimal plate spacing.

[0012] The beneficial effects of the method for determining the spacing of double-disc expanded support piles provided by the present invention are as follows: The present invention can calculate the optimal spacing of the discs through the physical parameters of the target soil and the support piles. Not only is the calculation process simple, but the calculated optimal spacing of the discs can also greatly improve the bearing capacity of the support piles and improve the efficiency of determining the spacing of the discs. It has high practical value in engineering.

[0013] Furthermore, in the above method for determining the spacing between the two-disc expanded support piles, the calculation process for the optimal spacing is as follows:

[0014]

[0015] Among them, L pjj The optimal plate spacing is represented by F, where F is the load-bearing capacity of the upper plate, and D is the load-b p γ is the diameter of the plate; h is the burial depth of the upper plate; γ is the unit weight of the soil; K0 is the lateral pressure coefficient of the soil; θ is the internal friction angle; c is the cohesion.

[0016] Furthermore, in the above method for determining the spacing between the two-disc expanded support piles, the calculation process for the bearing capacity of the upper disc is as follows:

[0017] F = Sf;

[0018] Where F is the bearing capacity of the upper plate; S is the projected area of ​​the upper plate; and f is the ultimate bearing capacity of the target soil.

[0019] Furthermore, in the above method for determining the spacing between the upper and lower disks of a double-disc expanded support pile, the calculation process for the projected area of ​​the upper disk is as follows:

[0020]

[0021] Where S is the projected area of ​​the upper plate; D p D is the diameter of the disk. z The diameter is the pile diameter.

[0022] Furthermore, in the above method for determining the spacing between the two-disc expanded support piles, the calculation process for the ultimate bearing capacity of the target soil is as follows:

[0023]

[0024] Where f is the ultimate bearing capacity of the target soil; c is the cohesion; θ is the internal friction angle; h is the burial depth of the upper plate; γ is the unit weight of the soil; K0 is the lateral pressure coefficient of the soil; D p D is the diameter of the disk. z The diameter is the pile diameter.

[0025] Furthermore, in the above method for determining the spacing between the double-disc expanded support piles, the physical parameters of the target soil are determined by indoor undrained shear tests. Attached Figure Description

[0026] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein:

[0027] Figure 1 This is a flowchart illustrating the method for determining the spacing between the two-disc expanded support piles.

[0028] Figure 2 This is a model dimension drawing of a double-disc expanded support pile;

[0029] Figure 3 It is the ultimate bearing capacity of double-disc expanded support piles under different disc spacings. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be understood that when the terms "first," "second," etc., are used in the claims, specification, and drawings of this invention, they are only used to distinguish different objects and not to describe a specific order. The terms "comprising" and "including" used in the specification and claims of this invention indicate the presence of the described features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof.

[0032] In one embodiment, a method for determining the spacing between the discs of a double-disc expanded-support pile is as follows: Figure 1 As shown, it includes the following steps:

[0033] 1) Obtain the physical parameters of the target soil and the double-disc expanded support pile.

[0034] The physical parameters of the target soil were determined by indoor undrained shear tests. The physical parameters of the target soil included the unit weight γ, the internal friction angle θ, the lateral pressure coefficient K0, and the cohesion c.

[0035] The physical parameters of the double-disc expanded-support pile are geometric design parameters, including the embedment depth h of the upper disc and the diameter D of the disc. p and pile diameter D z .

[0036] 2) Based on the cohesion c, internal friction angle θ, soil unit weight γ, upper plate burial depth h, and plate diameter D p The soil lateral pressure coefficient K0 and the pile diameter D z The ultimate bearing capacity f of the target soil is calculated.

[0037] The calculation process for the ultimate bearing capacity f of the target soil is as follows:

[0038]

[0039] 3) Based on the disk diameter D p and pile diameter D z The projected area S of the upper plate is calculated.

[0040] The calculation process for the projected area S is as follows:

[0041]

[0042] 4) Calculate the bearing capacity F of the upper plate based on the ultimate bearing capacity f of the target soil obtained in step 2) and the projected area S of the upper plate obtained in step 3).

[0043] The calculation process for the bearing capacity F of the upper plate is as follows:

[0044] F = Sf.

[0045] 5) Based on the bearing capacity of the upper plate obtained in step 4), combined with the plate diameter D p The spacing between the soil discs is calculated based on the burial depth h of the upper disc, the unit weight γ of the soil, the angle of internal friction θ, the lateral pressure coefficient K0 of the soil, and the cohesion c. This spacing is the optimal spacing L. pjj .

[0046] Optimal disk spacing L pjj The calculation process is as follows:

[0047]

[0048] The method of the present invention will be described in detail below with reference to a specific embodiment.

[0049] The thickness h of the upper and lower plates p =20mm, pile length l=275mm, disc diameter Dp =35mm, pile diameter D z =15mm, the burial depth of the upper plate is h=40mm. The physical parameters of the target soil were determined by indoor undrained shear tests as follows: cohesion c=0.93kPa, internal friction angle θ=16.5°, soil lateral pressure coefficient K0=0.84, and soil unit weight γ=18kN / m. 3 .

[0050] Based on the above calculations, the ultimate bearing capacity of the target soil is f = 3.57 kN, and the bearing capacity of the upper plate is F = 0.0028 kN. Therefore, the final result is:

[0051] Optimal disk spacing

[0052] To verify the accuracy of the results of this invention, the ultimate bearing capacity for different disc spacings was determined based on field tests, such as... Figure 3 As shown, Figure 3 Using the spacing between the bearing plates as the horizontal axis and the ultimate bearing capacity as the vertical axis, this invention tested the ultimate bearing capacity under five different bearing plate spacings. It can be seen that both excessively large and small spacing between the bearing plates affect the ultimate bearing capacity of the bearing plate piles. In this experiment, the optimal bearing plate spacing was 180mm, which is consistent with the optimal bearing plate spacing L calculated theoretically in this invention. pjj =177mm is close, with a small error.

[0053] This invention can calculate the optimal spacing between the piles by using the physical parameters of the target soil and the piles. Not only is the calculation process simple, but the calculated optimal spacing can also significantly improve the bearing capacity of the piles, making it highly practical in engineering.

[0054] The present invention can implement all or part of the processes in the above embodiments of the method, or it can be implemented by a computer program product. When the computer program product is running on the disc spacing determination device of the double-disc extrusion and expansion pile, the disc spacing determination device of the double-disc extrusion and expansion pile can implement the steps in the above method embodiments.

[0055] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0056] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0057] In the embodiments provided by this invention, it should be understood that the disclosed apparatus / computer devices and methods can be implemented in other ways. For example, the apparatus / computer device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0058] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for determining the spacing between the discs of a double-disc expanded support pile, characterized in that, The determination method includes: Obtain the physical parameters of the target soil and the double-disc extrusion pile. The physical parameters of the target soil include the lateral pressure coefficient, unit weight, internal friction angle, and cohesion. The physical parameters of the double-disc extrusion pile include the embedment depth of the upper disc, the disc diameter, and the pile diameter. The ultimate bearing capacity of the target soil is calculated based on cohesion, internal friction angle, unit weight of soil, depth of the upper plate, diameter of the plate, lateral pressure coefficient of soil, and pile diameter. The projected area of ​​the upper plate is calculated based on the diameter of the plate and the diameter of the pile. The bearing capacity of the hanging wall is calculated based on the ultimate bearing capacity of the target soil and the projected area of ​​the hanging wall; the bearing capacity of the hanging wall is positively correlated with the ultimate bearing capacity of the target soil and the projected area of ​​the hanging wall. Based on the bearing capacity of the upper plate, combined with the plate diameter, the burial depth of the upper plate, the unit weight of the soil, the angle of internal friction, the lateral pressure coefficient of the soil, and the cohesion, the plate spacing is calculated and determined to be the optimal plate spacing. The calculation process for the optimal disk spacing is as follows: ； in, To achieve the optimal disk spacing; For the bearing capacity of the upper plate; The diameter of the disk; The depth of the upper plate; The weight of soil; The lateral pressure coefficient of the soil; It is the internal friction angle; For cohesion, The calculation process for the bearing capacity of the upper plate is as follows: ； in, For the bearing capacity of the upper plate; This represents the projected area of ​​the upper plate; The ultimate bearing capacity of the target soil. The calculation process for the projected area of ​​the upper plate is as follows: ； in, This represents the projected area of ​​the upper plate; The diameter of the disk; The diameter of the pile. The calculation process for the ultimate bearing capacity of the target soil is as follows: ； in, The ultimate bearing capacity of the target soil; It is cohesive force; It is the internal friction angle; The depth of the upper plate; The weight of soil; The lateral pressure coefficient of the soil; The diameter of the disk; The diameter is the pile diameter.

2. The method for determining the spacing between the discs of a double-disc expanded support pile according to claim 1, characterized in that, The physical parameters of the target soil were determined by indoor undrained shear tests.

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