Production method and mold of high-strength prestressed spiral piles

Abstract

The present invention discloses a production method and a mold for high-strength prestressed spiral piles, which relate to the technical fields of pile foundation engineering and environmental protection. The method comprises the following steps: S1, vibrating concrete to obtain raw materials for high-strength components; S2, constructing a detachable mold with a preset shape, and loading a prestressed pipe pile steel cage into the mold; S3, closing the mold and tensioning prestressed tendons, and injecting the raw materials for high-strength components into the mold in a predetermined manner; S4, based on the centrifugal method, rotating the mold to produce high-strength prestressed components; S5, subjecting the high-strength prestressed components formed in step S4 to autoclave curing until reaching the specified strength, disassembling the mold, and taking out the finally obtained concrete structure. The present invention can obtain high-strength prestressed pipe piles. By designing a detachable film shell, the air problem generated during pouring is eliminated, so that the strength of the tooth part of the high-strength prestressed pipe pile is similar to that of the pile body, meeting the requirements of modern pile foundation engineering.

Description

Technical Field

[0001] The invention relates to the technical fields of pile foundation engineering and environmental protection in foundation engineering, and in particular to a production method and a mould for high-strength prestressed spiral piles. Background Art

[0002] In pile foundation projects in modern construction, prestressed pipe piles are usually used. The outer periphery of the pipe pile body is a smooth surface. Relying on the friction generated by the pressed pipe and the surrounding squeezed soil and the resistance generated by the soil plug at the pile end, the friction between the pipe and the soil layer is small, making it possible for the pipe pile to shift in poor soil layers.

[0003] Therefore, Japanese bamboo piles are equipped with raised parallel ribs at intervals on the outer periphery of high-strength prestressed pipe piles. However, due to the influence of soil properties, when the soil properties are good, it is difficult for them to sink, which increases the difficulty of engineering technology. Therefore, a patent named "interval spiral rib high-strength prestressed pipe pile" is proposed to solve the above problems. However, since the new pipe pile structure has undergone significant changes compared with the traditional pipe pile structure, the processing technology needs to be redesigned.

[0004] Compared with the existing bored cast-in-place piles, holes must be drilled on site with mud wall protection or rotary drilling. The hole diameter is the same as the pile diameter. The steel bars must be processed into cages on site and hoisted into the holes, and concrete must be poured on site. This method has high labor intensity on site construction, poor civilized construction working conditions, and the quality of the piles is difficult to guarantee.

[0005] Therefore, what this application aims to solve is how to design the above-mentioned high-strength prestressed pipe piles so that they can meet the specified strength and realize their mass production through process methods or molds. Summary of the invention

[0006] Purpose of the invention: Based on the problems mentioned in the background technology, the present invention proposes a method for producing high-strength prestressed spiral piles for producing high-strength pipe piles, and also proposes a mold to produce high-strength pipe piles with the aid of the above method.

[0007] Technical solution: S1, vibrating concrete to obtain high-strength component raw materials;

[0008] S2, constructing a detachable clamping unit with a preset shape, assembling the clamping unit, and placing the prestressed pipe pile reinforcement cage in the mold;

[0009] S3, closing the mold, tensioning the prestressed tendons, and injecting the high-strength component raw materials into the mold in a predetermined manner;

[0010] S4, based on the centrifugal method, rotating the mold to produce high-strength prestressed components;

[0011] S5. Steam-cure the high-strength prestressed component formed in step S4 to the specified strength, disassemble the mold, and take out the finally obtained concrete structure.

[0012] A further preferred technical solution is that the design process of the mold includes:

[0013] S21. Construct a matching upper semi-open steel pipe and a lower semi-open steel pipe as a mold closing unit; install fixing plates on the side walls of the upper semi-open steel pipe and the lower semi-open steel pipe; and open a preset number of connection holes on the fixing plates.

[0014] S22. Open installation holes on the outer sides of the upper semi-open steel pipe and the lower semi-open steel pipe, and weld a preset number of formwork shells at preset interval positions.

[0015] S23. Use high-strength bolts to pass through the connection holes at corresponding positions on the upper semi-open steel pipe and the lower semi-open steel pipe to close the mold and obtain the mold.

[0016] S24. Install a preset number of longitudinal stiffeners along the axis of the mold, and install a preset number of reversing stiffeners on the outer side of the mold to fasten the mold.

[0017] A further preferred technical solution is that the design process of the formwork shell in step S22 includes:

[0018] S22. Design an arc-shaped wire frame adapted to the side surface based on the side curvature of the mold.

[0019] S22. Design a local surface based on the structure of the spiral teeth. The area covered by the local surface is smaller than the area covered by the arc-shaped wire frame; the local surface rotates a preset angle along a certain straight line in space, and the local surface is at a preset distance from the arc-shaped wire frame. Its edge line is mapped to the arc-shaped wire frame to form a side surface that connects end to end; the side surface and the local surface are combined in space to form a crescent-shaped structure.

[0020] A further preferred technical solution is to design the formwork shell in step S22 as a detachable structure, and its use process includes the following steps:

[0021] Step 1. Design the formwork shell as an annular side wall adapted to the installation hole. The bottom of the annular side wall extends outward to form an installation part, and the formwork shell is installed on the outside of the installation hole through the installation part.

[0022] Step 2. Use an installation shell to be detachably connected to the annular side wall to form a detachable formwork shell.

[0023] A further preferred technical solution is that the installation shell is provided with insertion holes. After injecting the raw materials of the high-strength component into the mold, insert steel bars of a preset length through the insertion holes to achieve local reinforcement.

[0024] A further preferred technical solution is to reinforce the steel bars on the steel bar cage through the annular side wall.

[0025] For a further preferred technical solution, the upper half-open steel pipe and the lower half-open steel pipe in step S22 are used as a mold clamping unit, the radian of the mold clamping unit is reduced, and the number of mold clamping units is increased; a preset number of formwork shells are installed on the mold clamping unit at preset positions, and a preset number of mold clamping units are combined to form a mold.

[0026] For a further preferred technical solution, for the mold composed of a preset number of mold clamping units, the formwork shells distributed on the outside thereof are in a spiral shape along the length direction of the mold.

[0027] A mold, based on a high-strength prestressed spiral pile production method as described in any one of the above, the mold includes at least two mold clamping units, and a plurality of mold clamping units are assembled according to a preset assembly method to form a mold; a preset number of mounting holes are opened on the outer wall of the mold clamping unit, and the positions of the plurality of mounting holes are in a spiral shape for installing formwork shells.

[0028] For a further preferred technical solution, a bearing plate is installed at the end of the mold; a plurality of running wheels are installed on the outside of the mold; longitudinal stiffening ribs and circumferential stiffening ribs are welded respectively in the radial and circumferential directions of the mold.

[0029] Beneficial effects

[0030] 1. The present invention can obtain high-strength prestressed pipe piles. By designing a formwork shell with a detachable structure, the air problem generated during pouring is eliminated, so that the strength of the teeth part of the obtained high-strength prestressed pipe pile is similar to that of the pile body, meeting the requirements of modern pile foundation engineering.

[0031] 2. Compared with the well-known steel molds for high-strength prestressed concrete pipe piles, the multi-column spaced spiral tooth prestressed high-strength concrete pipe pile mold of the present invention can be processed based on common steel molds. By embedding crescent-shaped teeth in rows between the longitudinal and transverse stiffening ribs of the steel mold, the existing molds can be efficiently reused, saving mold materials. At the same time, there is no need to transform the existing pile diameter production line, realizing the rapid production of high-strength prestressed pipe piles with multi-column spiral teeth. Description of the drawings

[0032] Figure 1 is the production process flow chart of the present invention.

[0033] Figure 2 is the mold design flow chart of the present invention.

[0034] Figure 3 is the schematic structural diagram of the mold in the mold-clamped state of the present invention.

[0035] Figure 4 is the schematic structural diagram of the mold clamping unit of the present invention.

[0036] Figure 5 is the schematic structural diagram of the mold clamping unit of the present invention.

[0037] Figure 6 It is a schematic diagram of the formwork structure of the present invention.

[0038] Figure 7 It is a schematic diagram of the structure of another mold clamping unit of the present invention.

[0039] Figure 8 It is a schematic diagram of the structure of still another embodiment of the present invention.

[0040] Figure 9 It is a schematic diagram of the partial structure of still another embodiment of the present invention.

[0041] Figure 10 It is a schematic diagram of the structure of another embodiment of the present invention.

[0042] Figure 11 It is a schematic diagram of the characteristic parameters of another embodiment of the present invention, where a, b, and c are respectively parameters related to area, frictional resistance, and center distance of the circle.

[0043] Figure 12 It is a schematic diagram of the cross-section and tooth cross-section of another embodiment of the present invention, where a is the schematic diagram of the cross-section and b is the schematic diagram of the tooth cross-section.

[0044] Figures 1 to 7 Marked as: mold 1, formwork 2, longitudinal stiffening rib 3, circumferential stiffening rib 4, fixing plate 5, running wheel 6, bearing plate 7, upper semi-open steel pipe 11 of the mold, lower semi-open steel pipe 12 of the mold, quarter mold steel pipe 13, annular side wall 21, installation part 22, installation shell 23. Embodiment

[0045] The following further explains the present invention with reference to the accompanying drawings.

[0046] Based on the problems mentioned in the background art, in this embodiment, a new solution is designed for the existing pipe pile production process. In order to change the outer peripheral surface shape of the high-strength prestressed pipe pile to increase the frictional resistance around the pile and also take into account the prestressed pipe pile production process. Therefore, this embodiment proposes a method for producing high-strength concrete components, which is realized through the following steps:

[0047] The first step, vibrating the concrete to obtain the raw material of the high-strength component;

[0048] The second step, constructing a detachable and pre-set-shaped mold clamping unit for assembling into mold 1, and loading the prestressed pipe pile steel cage into mold 1;

[0049] The third step, closing the mold of mold 1, and performing prestressing tendon tensioning, and injecting the raw material of the high-strength component into mold 1 in a predetermined manner;

[0050] Step 4: Rotate the mold 1 based on the centrifugal method to produce high-strength prestressed components;

[0051] Step 5: Subject the high-strength prestressed components formed by the above method to autoclave curing until the specified strength, disassemble the mold 1, and take out the finally obtained concrete structure.

[0052] During the above process, the design of the mold 1 includes the following: As Figure 4 shown, in this embodiment, two semi-circular structures are used as the components of the mold 1 for assembly: First, construct the upper mold semi-open steel pipe 11 and the lower mold semi-open steel pipe 12 that are adapted to each other. Fixing plates 5 are installed on the side walls of the upper mold semi-open steel pipe 11 and the lower mold semi-open steel pipe 12, and a preset number of connection holes are opened on the fixing plates 5. Then, installation holes are opened on the outer sides of the upper mold semi-open steel pipe 11 and the lower mold semi-open steel pipe 12. The installation holes are adapted to the installation parts 22 at the bottom of the mold shell 2. According to the preset interval positions, a preset number of mold shells 2 are welded to the wall. Use high-strength bolts to pass through the connection holes at the corresponding positions on the upper mold semi-open steel pipe 11 and the lower mold semi-open steel pipe 12 to close the mold to obtain the mold 1. Install a preset number of longitudinal stiffening ribs 3 along the axis of the mold 1, and install a preset number of circumferential stiffening ribs 4 on the outer side of the mold 1 to fasten the mold 1.

[0053] Different from the prior art, this application improves the conventional pipe pile structure and optimizes the common annular rib structure, so the mold needs to be redesigned, and one of the inventions of this application lies in the design of the module. The design process of the mold shell 2 in this embodiment is as follows:

[0054] Design an arc-shaped wire frame adapted to the side surface according to the side surface radian of the mold 1;

[0055] Based on the structure of the spiral teeth, design a local surface. The area covered by the local surface is smaller than the area covered by the arc-shaped wire frame; the local surface rotates a preset angle along a certain straight line in space, and the local surface is at a preset distance from the arc-shaped wire frame. Its edge line is mapped to the arc-shaped wire frame to form a side surface that is connected end to end; the side surface and the local surface are combined into a crescent structure in space.

[0056] This embodiment will be described in combination with the content of actual production. First, concrete is vibrated on a centrifuge of an assembly line according to a specific rotation program to produce the pile body of a pipe pile as a raw material for high-strength components. Therefore, through the above-mentioned formwork 2, a structure with multiple rows of spaced spiral teeth arranged on the outer surface of the pile body can be obtained, and the tooth shape can be a twisted crescent tooth. The pile body of the pipe pile is formed by a precast pipe pile steel mold 1. The outer side walls of the upper half-open steel pipe 11 and the lower half-open steel pipe 12 are welded with a space-twisted crescent tooth steel formwork 2. The space-twisted crescent tooth steel formwork 2 is embedded between the longitudinal stiffening ribs 3 and the reversing stiffening ribs of the precast pipe pile steel mold 1. Fixed plates 5 are welded to both side walls of the upper half-open steel pipe 11 and the lower half-open steel pipe 12. After placing the prestressed pipe pile steel reinforcement cage, the formworks 2 are clamped at the fixed plates 5 with high-strength bolts. First, the prestressed tendons are tensioned, and then concrete is poured into the steel mold through a concrete delivery pipe.

[0057] In this embodiment, in combination with the production process of prestressed pipe piles and the processing process of precast steel molds, multiple rows of spaced crescent spiral teeth are used to replace the parallel spaced ring ribs of the well-known bamboo joint piles. The spiral teeth are arranged at intervals, and a reasonable twisted crescent tooth shape and pitch are adopted. The crescent teeth in a row can be embedded between the longitudinal and circumferential stiffening ribs 4 of the steel mold, which is more conducive to the centrifugal processing and forming of high-strength prestressed pipe piles with multiple rows of spiral teeth. And various hole-forming pipe pile machines can be used in combination with different engineering soil conditions, either directly screwed in, or stirred into cement soil and then screwed in, or grouted with cement mortar and then screwed in, or grouted with concrete and then screwed in.

[0058] Based on the above technical solution, when the structure of the formwork 2 is used, the construction personnel found during actual pouring that since the formwork 2 is a convex structure, after pouring, in the obtained finished product, the end shapes of some crescent teeth are incomplete, and the structure is brittle and easy to damage. The reason is that there is air inside the formwork 2. During pouring, the air inside the formwork 2 is not discharged in time or is difficult to discharge. At the same time, the concrete is less stressed at the formwork 2, resulting in the actual internal strength of the structure incorporated into the high-strength concrete inside the formwork 2 being less than that of other places, that is, the cylindrical main body of the mold 1 contains a large amount of concrete and is easily compacted and tightened under its own pressure.

[0059] Therefore, in this embodiment, the formwork 2 is modified to a detachable structure. The formwork 2 is designed as an annular side wall 21 adapted to the connection hole. The bottom of the annular side wall 21 extends outward to form an installation part 22, and is installed outside the connection hole through the installation part 22. An installation shell 23 is detachably connected to the annular side wall 21 to form a detachable formwork 2. Then, after injecting concrete, by disassembling the installation shell 23, the concrete can be supplemented, compacted, or the air can be exhausted, thereby ensuring the integrity of the pouring and the strength of the components inside the formwork 2.

[0060] Based on the technical solutions of Embodiment 1 and Embodiment 2, the spiral teeth obtained through the mold 1 in this application are of a pure concrete structure, and their hardness is much lower than that of the pipe pile itself. Therefore, in this embodiment, other technical solutions are proposed to enhance the hardness of the spiral teeth.

[0061] Technical solution 1: The installation shell 23 is provided with insertion holes. After injecting the raw material of the high-strength component into the mold 1, steel bars of a preset length are inserted through the insertion holes to achieve local reinforcement, and the insertion holes are sealed. Then, the formed spiral teeth contain steel bars inside, and their hardness is similar to that of the pipe pile itself.

[0062] Technical solution 2: Before concrete pouring, the steel bars are reinforced on the steel reinforcement cage through the annular side wall 21, that is, after the steel reinforcement cage is placed in the mold 1, the steel bars are connected to the steel reinforcement cage through the annular side wall 21, and then concrete pouring is carried out. Through the above solutions, the hardness of the finished product can be high and it is not easily damaged. In particular, the strength of the obtained spiral teeth is close to the strength of the pipe pile column body.

[0063] In the above-mentioned embodiment, two common semi-circular structures are assembled to achieve mold closing. Therefore, there are usually only two rows of spiral teeth on the outer side of the formed pipe pile. In order to increase the number of spiral teeth, fit them into a thread structure, and increase the strength of the overall spiral teeth, in this embodiment, the upper semi-open steel pipe 11 and the lower semi-open steel pipe 12 are used as mold closing units, the radian of the mold closing unit is reduced, the number of mold closing units is increased, and a preset number of mold shells 2 are installed at preset positions on the mold closing unit. The preset number of mold closing units are combined to form the mold 1.

[0064] This embodiment is described by taking the example of four quarter-mode steel pipes 13 being connected and closed by high-strength bolts at the fixing plate 5. The multi-row spaced spiral tooth high-strength prestressed pipe pile body is formed through the precast pipe pile steel mold 1. The outer side walls of the four quarter-mode steel pipes 13 are welded with space-twisted crescent-shaped tooth steel mold shells 2. The space-twisted crescent-shaped tooth steel mold shells 2 are embedded between the longitudinal stiffening ribs 3 and the reversing stiffening ribs of the precast pipe pile steel mold 1. Fixed plates 5 are welded on both side walls of each quarter-mode steel pipe 13. After the prestressed pipe pile steel reinforcement cage is placed, the four mold shells 2 are connected and closed in pairs by high-strength bolts at the fixing plate 5. First, the prestressed tendons are tensioned, and then the concrete in the steel mold is poured through the concrete delivery pipe.

[0065] Furthermore, for the mold 1 composed of a preset number of mold closing units, the mold shells 2 distributed on its outer part are in a spiral shape along the length direction of the mold 1. Then, the distribution of the formed spiral teeth is also in a spiral shape.

[0066] When manufacturing pipe piles, the steel mold 1 can be divided into two or four combined molds according to the number of rows of teeth. The protruding twisted crescent-shaped tooth mold shell 2 is embedded between the longitudinal and transverse stiffeners of the prefabricated steel mold and welded to the pile body steel mold as a whole. The production process is the same as that of conventional precast pipe piles. Using the precast multi-row spaced spiral tooth pipe pile of the present invention, the common use of compression and tension piles can be realized, the amount of concrete used can be reduced, the economic index is good, and the effect of small pile diameter and high bearing capacity can be achieved.

[0067] Based on the above process method, this embodiment proposes a mold 1. The mold 1 includes at least two combined mold units, and multiple combined mold units are assembled according to a preset assembly method to form the mold 1; a preset number of mounting holes are opened on the outer wall of the combined mold unit, and the positions of the multiple mounting holes are in a spiral shape for installing the mold shell 2. A bearing plate 7 is installed at the end of the mold 1, and multiple running wheels 6 are installed on the outside of the mold 1. Longitudinal stiffeners 3 and circumferential stiffeners 4 are welded to the mold 1 in the radial and circumferential directions respectively. Through the above structure, the production of preset high-strength pipe piles is realized.

[0068] As Figures 10 to 12 shown, in this application, the spiral pile produced by the mold is described. Since the relevant parameters of the spiral pile are defined by the mold, the definition of some parameters of the spiral pile is also the definition of the mold.

[0069] As Figure 11 in Figures a, b, c of Figure 12 and Figures a, b of

[0070] The design of the spiral pile satisfies the following conditions:

[0071] The bottom height, top height, pitch, central angle of the inner-side sector horizontal projection, central angle of the outer-side sector horizontal projection, angles between the upper and lower sides of the tooth and the horizontal plane, angle between the tooth helix and the vertical direction, etc. of the spiral teeth satisfy the following conditions:

[0072] First constraint: 0.7f t A i ≥τ tz A t +τ oz A o +τ bz A b +τ bsz A bs ;

[0073] Second constraint: 0.35f t A i d≥τ ty A t r t +0.5τ oy A o D+τ by Ab r b +τ bsy A bs r bs ;

[0074] wherein, A i = αbd 、A o = βaD ;

[0075] A t =A b =h×(l 1 +l 2 ) / 2,

[0076] l 1 =(α / π)×sqrt[s 2 +(πd) 2 ;

[0077] l 2 =(β / π)×sqrt[s 2 +(πD) 2 ;

[0078] A ts =A bs =h ts ×(a + b) / 2;

[0079] h ts =h bs =(D / 2)×csc(α - β) / 2 - d / 2×cot(α - β) / 2;

[0080] θ = arctan (s / πd);

[0081] τ tz = τ t cosθ; τ ty = τ t sinθ; τ oz = τ o cosθ; τ oy = τ o sinθ; τ bz = τ b cosθ; τ by = τ b sinθ;

[0082] τ bsz = τ bs cosθ; τ bsy = τ bs sinθ; τ tsz = τ ts cosθ; τ tsy = τ ts sinθ;

[0083] r t =r b = d / 2 + 1 / 3 × h × [1 +l 2 / (l 1 +l 2 ) ; r ts =r bs =d / 2+ (D - d) / (2h ts ) ×h / 3× [1 + a / (a + b) 。

[0084] A i is the inner side area of the tooth; A o is the outer side area of the tooth; A t is the upper side area of the tooth; A b is the lower side area of the tooth; A ts is the upper side end face area of the tooth; A bs is the lower side end face area of the tooth; f t is the design value of the tensile strength of concrete.

[0085] τ o is the soil friction resistance on the outer side of the tooth; τ t is the soil friction resistance on the upper side of the tooth; τ b is the soil friction resistance on the lower side of the tooth; τ ts is the soil friction resistance on the upper side end face of the tooth; τ bs is the soil friction resistance on the lower side end face of the tooth.

[0086] r o is the horizontal distance from the centroid of the outer side of the tooth to the center of the pile cross-section; r t ​​is the horizontal distance from the centroid of the upper side surface of the tooth to the center of the pile cross-section; r b is the horizontal distance from the centroid of the lower side surface of the tooth to the center of the pile cross-section; r ts is the horizontal distance from the centroid of the upper end surface of the tooth to the center of the pile cross-section; r bs is the horizontal distance from the centroid of the lower end surface of the tooth to the center of the pile cross-section. b is the height of the tooth bottom; a is the top height; h is the tooth height; s is the pitch; d is the inner diameter of the pile; D is the outer diameter of the pile. α is the central angle of the horizontal projection of the inner sector of the tooth; β is the central angle of the horizontal projection of the outer sector of the tooth; φ is the angle between the upper and lower side surfaces of the tooth and the horizontal plane; θ is the angle between the tooth helix and the vertical direction.

[0087] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A production method of high-strength prestressed spiral piles, characterized in that, it includes the following steps: S1. Vibrate the concrete to obtain raw materials for high-strength components; S2. Construct a detachable mold unit with a preset shape, assemble the mold unit, and install a prestressed pipe pile steel cage in the mold; S3. Close the mold and perform tensioning of prestressed tendons, and inject the raw materials for high-strength components into the mold in a predetermined manner; S4. Based on the centrifugal method, rotate the mold to produce high-strength prestressed components; S5. Steam-cure the high-strength prestressed components formed in step S4 to the specified strength, disassemble the mold, and take out the finally obtained concrete structure; The design process of the mold includes: S21. Construct a matching upper half-open steel pipe and a lower half-open steel pipe as the mold unit; fixing plates are installed on the side walls of the upper half-open steel pipe and the lower half-open steel pipe; a preset number of connection holes are opened on the fixing plates; S22. Open installation holes on the outer sides of the upper half-open steel pipe and the lower half-open steel pipe, and weld a preset number of formwork shells at preset interval positions; S23. Use high-strength bolts to pass through the corresponding connection holes on the upper half-open steel pipe and the lower half-open steel pipe to close the mold to obtain the mold; S24. Install a preset number of longitudinal stiffeners along the axis of the mold, and install a preset number of commutation stiffeners on the outer side of the mold to fasten the mold; The design process of the formwork shell in step S22 includes: S22. Based on the side curvature of the mold, design an arc-shaped wire frame that matches the side; S22. Based on the structure of the spiral teeth, design a local surface, and the area covered by the local surface is smaller than the area covered by the arc-shaped wire frame; the local surface rotates a preset angle along a certain straight line in space, and the local surface is at a preset distance from the arc-shaped wire frame, and its edge line is mapped to the arc-shaped wire frame to form a side that is connected end to end; the side and the local surface are combined into a crescent-shaped structure in space; The structural parameters of the spiral teeth are: First constraint: 0.7f t A i ≥τ tz A t +τ oz A o +τ bz A b +τ bsz A bs ; Second constraint: 0.35f t A i d ≥ τ ty A t r t +0.5τ oy A o D + τ by A b r b +τ bsy A bs r bs ; Wherein, A i = αbd 、A o = βaD ; A t =A b =h×(l 1 +l 2 ) / 2, l 1 = (α / π) × sqrt[s 2 + (πd) 2 ; l 2 =(β / π)×sqrt[s 2 +(πD) 2 ; A ts = A bs = h ts ×(a + b) / 2; h ts = h bs = (D / 2) × csc(α - β) / 2 - d / 2 × cot(α - β) / 2; θ = arctan (s / πd); τ tz = τ t cosθ; τ ty = τ t sinθ; τ oz = τ o cosθ; τ oy = τ o sinθ; τ bz = τ b cosθ; τ by = τ b sinθ; τ bsz = τ bs cosθ; τ bsy = τ bs sinθ; τ tsz = τ ts cosθ; τ tsy = τ ts sinθ; r t =r b = d / 2 + 1 / 3×h× [1 +l 2 / (l 1 +l 2 ) ]； r ts =r bs =d / 2+ [ (D - d) / (2h ts ) ] ×h / 3× [1 + a / (a + b) ]； A i is the area of the inner side of the tooth; A o is the area of the outer side of the tooth; A t is the area of the upper side of the tooth; A b is the area of the lower side of the tooth; A ts is the area of the upper end face of the tooth; A bs is the area of the lower end face of the tooth; f t is the design value of the tensile strength of concrete; τ o is the frictional resistance of the soil on the outer side of the tooth; τ t is the frictional resistance of the soil on the upper side of the tooth; τ b is the frictional resistance of the soil on the lower side of the tooth; τ ts is the frictional resistance of the soil on the upper end face of the tooth; τ bs is the frictional resistance of the soil on the lower end face of the tooth; r o is the horizontal distance from the centroid of the outer side surface of the tooth to the center of the circle of the pile cross-section; r t is the horizontal distance from the centroid of the upper side surface of the tooth to the center of the circle of the pile cross-section; r b is the horizontal distance from the centroid of the lower side surface of the tooth to the center of the circle of the pile cross-section; r ts is the horizontal distance from the centroid of the upper end surface of the tooth to the center of the circle of the pile cross-section; r bs is the horizontal distance from the centroid of the lower end surface of the tooth to the center of the circle of the pile cross-section; b is the height of the tooth bottom; a is the top height; h is the tooth height; s is the pitch; d is the inner diameter of the pile; D is the outer diameter of the pile; α is the central angle of the horizontal projection of the inner side sector of the tooth; β is the central angle of the horizontal projection of the outer side sector of the tooth; φ is the angle between the upper and lower side surfaces of the tooth and the horizontal plane; θ is the angle between the tooth helix and the vertical direction; Design the formwork shell in step S22 as a detachable structure, and its use process includes the following steps: Step 1. Design the formwork shell as an annular side wall that matches the installation hole, and the bottom of the annular side wall extends outward to form an installation part, and install it on the outside of the installation hole through the installation part; Step 2. Use an installation shell to be detachably connected to the annular side wall to form a detachable formwork shell.

2. A production method of high-strength prestressed spiral piles according to claim 1, characterized in that, the installation shell is provided with a jack, and after injecting the raw materials for high-strength components into the mold, insert a steel bar with a preset length through the jack to achieve local reinforcement.

3. A production method of high-strength prestressed spiral piles according to claim 2, characterized in that, The steel bars are reinforced on the steel reinforcement cage through the annular side wall.

4. A method for manufacturing a high-strength prestressed spiral pile according to claim 1, characterized in that the upper die semi-open steel pipe and the lower die semi-open steel pipe in step S22 are used as a die clamping unit, the radian of the die clamping unit is reduced, and the number of die clamping units is increased; a preset number of formwork shells are installed on the die clamping unit at preset positions, and a preset number of die clamping units are combined to form a mold.

5. A method for manufacturing a high-strength prestressed spiral pile according to claim 4, characterized in that for the mold composed of a preset number of the die clamping units, the formwork shells distributed on the outside thereof are in a spiral shape along the length direction of the mold.

6. A mold based on a method for manufacturing a high-strength prestressed spiral pile according to any one of claims 1-5, characterized in that the mold includes at least two die clamping units, and a plurality of the die clamping units are assembled according to a preset assembly method to form a mold; a preset number of mounting holes are opened on the outer wall of the die clamping unit, and the positions of the plurality of mounting holes are in a spiral shape for installing formwork shells.

7. A mold according to claim 6, characterized in that a bearing plate is installed at the end of the mold; a plurality of running wheels are installed on the outside of the mold; longitudinal stiffening ribs and circumferential stiffening ribs are welded respectively in the radial and circumferential directions of the mold.

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