A negative engraving fractal texture biomimetic pile and a manufacturing method thereof

Abstract

This invention discloses a biomimetic pile with engraved fractal texture and its manufacturing method. The biomimetic pile with engraved fractal texture includes a pile body; wherein: the outer surface of the pile body has a plurality of grooves; and the interior of the grooves has a plurality of biomimetic texture grooves. This invention obtains a pile with engraved fractal texture by creating grooves on the outer surface of the pile body and then creating biomimetic texture grooves within the grooves. This creates a near-infinite contact boundary on a finite surface area, resulting in an order-of-magnitude increase in the effective contact area between the pile and the soil. The concave structure tightly embeds the soil, forming a strong three-dimensional spatial interlocking effect, thereby significantly improving the vertical bearing capacity, pull-out force, and lateral stability of the pile.

Description

Technical Field

[0001] This invention belongs to the field of pile foundation technology in geotechnical engineering, and specifically relates to a biomimetic pile with engraved fractal texture and its manufacturing method. Background Technology

[0002] Pile foundations are key components in buildings, bridges, wind power facilities, and other engineering projects that transfer loads to deep soil layers. Traditional precast piles, such as prestressed concrete pipe piles and steel pipe piles, often have smooth cylindrical surfaces or simple raised threads or ribs. Their bearing capacity mainly depends on the pile side friction and pile end resistance. For example, patent application number CN202511549357.X discloses a biomimetic cross-shaped plate pipe pile with an outer wall resembling snake scales, an inner wall resembling tree roots, and a bottom end resembling tooth roots, as well as its manufacturing method. The biomimetic cross-shaped plate pipe pile includes a cylindrical pipe pile, a cross-shaped plate pile, and a cross-shaped plate pile. The cylindrical pipe pile features a cross-shaped plate and a tooth-like root structure. The outer wall of the cylindrical pipe pile has multiple snake-scale-like protrusions, and the inner wall has multiple tree-root-like protrusions. The cross-shaped plate is located inside the cylindrical pipe pile, dividing the circular cavity inside into four first sector-shaped chambers. The tooth-like root structure is located at the bottom end of the cylindrical pipe pile. This patent, through multiple biomimetic designs, synergistically enhances the pile's moment of inertia, end resistance, side friction, and pull-out resistance, thereby significantly improving the comprehensive bearing capacity of the pipe pile under the combined action of vertical and horizontal loads.

[0003] Precast piles, leveraging the advantages of industrialized production, significantly improve construction efficiency and project quality. Their core advantages include: Convenience of construction: factory prefabrication allows for customized lengths or diameters, requiring only on-site assembly, reducing on-site work by over 60%; All-weather construction: overcoming seasonal limitations, such as avoiding winter concrete curing periods for cast-in-place piles, shortening the construction period by 30%–50%; Environmental friendliness: eliminating the need for large-scale excavation, reducing earthwork by 80% and lowering the risk of groundwater pollution by 90%; Quality stability: using C60–C80 high-strength concrete with a compressive strength ≥60MPa, load-bearing capacity of 200–300kN / m², and a service life exceeding 50 years; Seismic durability: passing ISO standard seismic testing, capable of withstanding magnitude 8 earthquakes, suitable for heavy structures such as high-rise buildings and bridges.

[0004] However, traditional pile foundations still have the following shortcomings:

[0005] (1) The mechanical interlocking between the smooth pile side surface and the soil is weak, and the side friction resistance is limited;

[0006] (2) Although piles with raised threads can improve bearing capacity, the raised part is easily damaged during construction and increases the resistance to pile driving, making construction difficult in hard soil layers.

[0007] (3) Whether it is a smooth surface or a raised texture, there is still a huge room for improvement in the contact area with the soil and the three-dimensional interlocking effect, and the potential of the soil around the pile has not been fully utilized.

[0008] In nature, biological structures such as tree roots and coral surfaces can achieve maximum contact and anchoring with the surrounding medium within a limited space through complex fractal morphology, exhibiting extremely high load-bearing and pull-out resistance efficiency. Inspired by this, applying the principles of fractal geometry to pile design is a cutting-edge direction for improving pile foundation performance. Summary of the Invention

[0009] The purpose of this invention is to address the shortcomings of existing technologies by providing a biomimetic pile with engraved fractal texture and its manufacturing method. This invention primarily mimics the fractal structure of natural root systems. Without increasing construction difficulty, it maximizes the pile-soil contact area and three-dimensional interlocking effect through geometric means, significantly improving the pile's bearing capacity, pull-out resistance, and stability. It offers advantages such as construction friendliness, flexible design, and economic and environmental friendliness.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A biomimetic pile with engraved fractal texture includes a pile body; wherein: the outer surface of the pile body has a plurality of grooves; and the interior of the grooves has a plurality of biomimetic texture grooves.

[0012] In this invention, by creating grooves on the outer surface of the pile body and then creating biomimetic textured grooves within the grooves, a pile body with engraved fractal textures is obtained. This creates a near-infinite contact boundary on a limited surface area, resulting in an order-of-magnitude increase in the effective contact area between the pile and the soil. The concave structure tightly embeds the soil, forming a powerful three-dimensional spatial interlocking effect, which significantly improves the vertical bearing capacity, pull-out force, and lateral stability of the pile.

[0013] As a further explanation of the present invention, the biomimetic texture grooves in the same groove are continuously distributed along the axial direction and spaced apart along the circumferential direction on the surface of the pile body.

[0014] As a further explanation of the present invention, the shape of the biomimetic texture groove includes one or more of the following: Sierpinski triangle, Koch curve, tree root bifurcation network, Mandelbrot boundary line, or Cantor dust.

[0015] In terms of visual presentation, the biomimetic texture grooves of the Sierpinski triangle, after being engraved, produce a delicate sense of layering and depth due to its self-similar fractal structure. When light shines on it, the grooves form a gradient shadow, highlighting the geometric precision of the pattern and creating a dynamic three-dimensional effect, making the static carving appear vivid. In terms of process implementation, the recursive characteristics of the fractal pattern are suitable for the repetitive operation of engraving, facilitating mechanized processing. At the same time, its infinite details can enrich the texture within a limited area, improving carving efficiency.

[0016] Due to its self-similarity and fractal dimension, the Koch curve can be used to generate self-similar geometric figures. After intaglio, not only is its perimeter infinite, but the distance between any two points on the curve is also infinite.

[0017] The biomimetic texture grooves mimicking the branching network of tree roots, combined with the engraved texture that mimics the organic feel of biological forms, present a smooth and vibrant visual effect when combined with the smooth and firm characteristics of the engraved lines.

[0018] The Mandelbrot set boundary is a typical representative of fractal geometry in complex dynamic systems. Its boundary has infinite complexity and exhibits a self-similar fine structure at any magnification scale. The self-similar structure can interact with external fields such as sound waves or shock waves at different scales, enhancing energy absorption efficiency. For example, it can provide broadband noise attenuation in acoustic materials. Structural compactness and surface area optimization: the infinitely tortuous boundary maximizes the surface area in a finite space, similar to the efficient material exchange design of biological tissues such as alveoli or roots. It is suitable for microfluidic channels or catalyst carriers. Fractal topology can disperse stress concentration and reduce the risk of local damage. Analogous to the gradient structure of shells or bones, it improves structural durability.

[0019] The self-similarity of the biomimetic texture grooves of Cantor dust allows the texture to present a consistent and complex aesthetic at different scales. The engraving process can permanently engrave fractal patterns into the pile material, highlighting the warm and smooth texture of the material.

[0020] As a further explanation of the present invention, the depth of the groove is 1% to 5% of the outer diameter of the pile body, and the ratio of the maximum width to the depth of the groove is between 1:1 and 5:1.

[0021] The geometry of the groove directly affects the frictional resistance between the pile and the soil, or the embedment depth. A suitable groove depth helps the pile fully embed into the bearing stratum, improving end bearing capacity and overturning resistance; width control ensures a tight interlock, preventing misalignment or slippage under load, thus enhancing the overall stability of the support structure. The width and depth of the groove must precisely match the protrusions of the paired piles to form a tight watertight or airtight connection. If the groove is too shallow or too narrow, gaps may appear at the connection, reducing the integrity of the overall structure and affecting impermeability or shear strength; conversely, if the groove is too deep or too wide, it may weaken the effective area of ​​the pile cross-section, causing stress concentration and increasing the risk of localized fatigue failure.

[0022] As a further explanation of the present invention, the characteristic dimension of the biomimetic texture groove's contour pattern is not less than 5mm. That is, the minimum dimension of the contour pattern of a single biomimetic texture groove is 5mm, to ensure the compactness of the concrete pouring and the mechanical effectiveness of the texture.

[0023] As a further explanation of the present invention, the pile body is a prestressed concrete pipe pile, a solid square pile, a steel pipe pile, or a composite material pile.

[0024] The present invention also provides a method for manufacturing the above-mentioned biomimetic pile with engraved fractal texture, comprising the following steps:

[0025] Step 1: Mold preparation;

[0026] Based on the predetermined engraved fractal texture (including grooves and biomimetic texture grooves) pattern design, the corresponding raised fractal pattern is processed on the inner wall of the pile mold through CNC engraving, 3D printing or precision casting process.

[0027] Step two: Concrete pouring and vibration;

[0028] Arrange a steel reinforcement skeleton inside the mold with the raised fractal pattern, pour concrete and vibrate it thoroughly to ensure that the concrete completely fills the mold cavity and forms a dense shape.

[0029] Step 3: Curing and demolding;

[0030] After the concrete is poured, it is cured according to standard. After the concrete reaches the specified strength, it is demolded. After demolding, the surface of the pile body forms an inwardly recessed fractal texture that corresponds to the raised fractal pattern on the inner wall of the mold.

[0031] Step four, surface treatment;

[0032] After demolding, the engraved fractal texture of the pile body is deburred and moistened for curing to obtain the engraved fractal texture bionic pile.

[0033] As a further explanation of the method described in this invention, the concrete pouring and vibration in step two specifically includes:

[0034] 21) Reinforcing bar cage layout: The layout of the reinforcing bar cage must strictly follow the design drawings to ensure that the specifications, spacing, protective layer thickness and lap length of the reinforcing bars meet the specifications. When installing in the mold, spacers or brackets should be used to fix the reinforcing bars to prevent displacement during the pouring process.

[0035] 22) Concrete pouring: Concrete shall be poured in layers according to the design mix proportion and in a uniform manner. The thickness of each layer shall not exceed 1.25 times the length of the vibrating rod. During the pouring process, the slump and fluidity of the concrete shall be controlled to avoid segregation.

[0036] 23) Vibration operation: Use an immersion vibrator and follow the principle of quick insertion and slow withdrawal. The spacing between vibration points should be less than 1.5 times the effective radius of the vibrator. In key areas, including areas with dense reinforcement and around embedded parts, the vibration time should be extended until the surface is covered with slurry and no air bubbles escape.

[0037] As a further explanation of the method described in this invention, the curing and demolding of the mold body in step three is as follows:

[0038] 31) Curing conditions and time: The concrete should be covered and watered for curing within 1 to 2 hours after pouring to keep the surface moist. When the temperature is low, below 5℃, it is necessary to cover it with straw bags for insulation. The curing time is based on 30% of the strength after 28 days of curing under standard conditions of 20±2℃ and relative humidity above 95%.

[0039] 32) Side formwork removal: When removing the side formwork, the concrete strength must ensure that the surface and edges of the pile are not damaged. After removal, the formwork should be cleaned in time and stacked neatly to avoid being stacked on the freshly poured pile. After the formwork is removed, the appearance quality of the pile should meet the requirements, with a flat and dense surface, a corner chipping depth of less than 10mm, a local honeycomb defect area of ​​less than 0.5% of the total surface area of ​​the pile, a shrinkage crack depth of no more than 20mm and a width of no more than 0.15mm, a transverse crack length of less than 1 / 2 of the side length, and no honeycomb, pitting or cracks at the top and tip of the pile.

[0040] 33) Removal of end formwork for inter-compartment: The removal of end formwork for inter-compartment should also be carried out when the concrete strength reaches 30% of the standard strength after 28 days of curing. The operation procedure is the same as that for side formwork removal.

[0041] 34) Overlapping fabrication and lifting and transportation: If it is necessary to overlap the upper piles after demolding, the lower pile body shall be used as the bottom mold. The number of overlapping layers shall be less than 4. The pile body shall be lifted after the concrete strength reaches 70% of the design value. The lifting points shall be set according to the design specifications and padded. Transportation shall be carried out when the strength reaches 100%.

[0042] As a further explanation of the method described in this invention, the surface treatment in step four specifically includes:

[0043] 41) Deburring treatment: After demolding, first clean the burrs on the engraved fractal texture of the pile body. Use a fine chisel or wire brush to gently remove loose particles, sharp edges and micro-cracks on the concrete surface caused by demolding, so as to avoid damaging the engraved fractal texture structure. When operating, it is necessary to follow the texture direction to prevent the scratches from expanding or the edges from cracking.

[0044] 42) Moistening and curing implementation: Moistening and curing should be carried out immediately after deburring to ensure that the concrete hydration reaction is sufficient. Spray water or cover with wet burlap or straw mats to keep the surface of the pile continuously moist. The curing time should not be less than 7 days. During this period, direct sunlight and wind drying should be avoided. The humidity should be maintained above 90% and the temperature should not be lower than 5℃.

[0045] 43) Surface defect inspection and repair: During the curing process, it is necessary to check whether there are defects such as mud inclusion, exposed reinforcement or insufficient strength in the engraved fractal texture. If mud inclusion or insufficient strength is found in the area, it is necessary to chisel it down to the depth of the fresh concrete surface layer 10-15cm, clean the reinforcement and pour C35 concrete. If the main reinforcement is exposed or broken, it is necessary to repair it by double-sided lap welding or pouring concrete.

[0046] 44) Post-curing treatment: After the curing period, remove surface residues and perform final cleaning of the engraved fractal texture. If decorative or protective treatment is required, apply concrete protectant, but ensure that the surface is completely dry and free of dust.

[0047] Advantages of this invention:

[0048] 1. This invention uses geometric methods to design engraved fractal textures on the outer surface of the pile body. Without increasing the pile diameter or construction difficulty, it creates a near-infinite contact boundary on a limited surface area, resulting in an order-of-magnitude increase in the effective contact area between the pile and the soil. The concave structure tightly embeds the soil, forming a powerful three-dimensional interlocking effect, thereby increasing the vertical bearing capacity and pull-out resistance by 50% to several times.

[0049] 2. Compared with existing raised textured piles, the engraved fractal texture of the present invention is less prone to damage during transportation, hoisting, and pile driving and pressing, and will not significantly increase pile driving resistance, thus having good construction adaptability and durability.

[0050] 3. The engraved fractal texture of the present invention can guide the soil around the pile to form a multi-scale, interrelated reinforced stress arch, transforming a larger area of ​​soil into part of the load-bearing structure, improving the load transfer mechanism and reducing settlement.

[0051] 4. This invention can optimize the design of different engraved fractal texture patterns, groove depths and distribution densities according to different engineering geological conditions such as sand and clay, so as to achieve customized performance.

[0052] 5. When achieving the same load-bearing requirements, the biomimetic pile with engraved fractal texture of the present invention reduces the pile length, pile diameter or number of piles, saves materials, reduces the overall project cost and carbon emissions, and conforms to the concept of green construction.

[0053] 6. The present invention creates an engraved fractal texture on the outer surface of the pile body. That is, by engraving a recessed pattern on the surface of the pile body, the surface area of ​​the pile body exposed to the external environment is reduced, thereby reducing the risk of surface deterioration caused by moisture, ultraviolet rays or microbial erosion. This treatment method is especially suitable for pile bodies in underground or humid environments and can effectively extend their service life.

[0054] 7. The engraved fractal texture of the present invention increases the friction on the surface of the pile body, improves the interlocking effect at the mortise and tenon joints with other components, thereby enhancing the stability of the overall structure. At the same time, the engraving depth is usually controlled within the range of 2 to 3 mm to avoid excessively weakening the cross-sectional strength of the pile body, thus balancing aesthetics and mechanical performance.

[0055] 8. The intaglio fractal texture of the present invention can express the brushwork and charm of traditional Chinese painting through the depth and pauses of the lines, forming a visual effect that contrasts sharply with the pile body and improving the aesthetics of the pile body. Attached Figure Description

[0056] Figure 1 This is a front view of a biomimetic pile with engraved fractal texture in one embodiment of the present invention.

[0057] Figure 2 for Figure 1 An enlarged 3D schematic diagram of the biomimetic texture groove (Serpinski triangle) inside the groove at point A.

[0058] Figure 3 This is a flowchart of a manufacturing method according to an embodiment of the present invention.

[0059] Figure 4 This is a top view of the present invention.

[0060] In the diagram: 1-Pile body; 2-Groove; 3-Bionic texture groove. Detailed Implementation

[0061] The invention will be further described below with reference to the accompanying drawings.

[0062] Example 1: A biomimetic pile with engraved fractal texture, comprising a pile body 1; wherein, as shown in the figure... Figure 1 , 2As shown in Figure 4, the outer surface of the pile body 1 has several grooves 2; the interior of each groove 2 has a biomimetic textured groove 3. The shape of the biomimetic textured groove 3 is a Sierpinski triangle. The depth of each groove 2 is 1% of the outer diameter of the pile body 1; the ratio of the maximum width to the depth of each groove 2 is 1:1. The pile body 1 is a prestressed concrete pipe pile.

[0063] Example 2: A biomimetic pile with engraved fractal texture, comprising a pile body 1; wherein, a plurality of grooves 2 are formed on the outer surface of the pile body 1; and biomimetic texture grooves 3 are formed inside the grooves 2. The shape of the biomimetic texture grooves 3 is a Sierpinski triangle. The depth of the grooves 2 is 2% of the outer diameter of the pile body 1. The ratio of the maximum width to the depth of the grooves 2 is 2:1. The pile body 1 is a solid square pile.

[0064] Example 3: A biomimetic pile with engraved fractal texture, comprising a pile body 1; wherein, a plurality of grooves 2 are formed on the outer surface of the pile body 1; and biomimetic texture grooves 3 are formed inside the grooves 2. The shape of the biomimetic texture grooves 3 is a Koch curve. The depth of the grooves 2 is 3% of the outer diameter of the pile body 1. The ratio of the maximum width to the depth of the grooves 2 is 3:1. The pile body 1 is a steel pipe pile.

[0065] Example 4: A biomimetic pile with an engraved fractal texture, comprising a pile body 1; wherein, a plurality of grooves 2 are formed on the outer surface of the pile body 1; and biomimetic texture grooves 3 are formed inside the grooves 2. The shape of the biomimetic texture grooves 3 is a network of branching branches resembling tree roots. The depth of the grooves 2 is 4% of the outer diameter of the pile body 1. The ratio of the maximum width to the depth of the grooves 2 is 4:1. The pile body 1 is a composite material pile.

[0066] Example 5: A biomimetic pile with engraved fractal texture, comprising a pile body 1; wherein, a plurality of grooves 2 are formed on the outer surface of the pile body 1; and biomimetic texture grooves 3 are formed inside the grooves 2. The shape of the biomimetic texture grooves 3 is the boundary line of the Mandelbrot junction. The depth of the grooves 2 is 5% of the outer diameter of the pile body 1. The ratio of the maximum width to the depth of the grooves 2 is 5:1. The pile body 1 is a prestressed concrete pipe pile.

[0067] Example 6: A biomimetic pile with engraved fractal texture, comprising a pile body 1; wherein, a plurality of grooves 2 are formed on the outer surface of the pile body 1; and biomimetic texture grooves 3 are formed inside the grooves 2. The shape of the biomimetic texture grooves 3 is Cantor dust. The depth of the grooves 2 is 3% of the outer diameter of the pile body 1. The ratio of the maximum width to the depth of the grooves 2 is 1:1. The pile body 1 is a steel pipe pile.

[0068] Example 7: A biomimetic pile with engraved fractal texture, comprising a pile body 1; wherein, a plurality of grooves 2 are formed on the outer surface of the pile body 1; and biomimetic texture grooves 3 are formed inside the grooves 2. The shapes of the biomimetic texture grooves 3 include Sierpinski triangles and Koch curves, that is, biomimetic texture grooves with Sierpinski triangles and biomimetic texture grooves with Koch curves are provided on the pile body 1. The depth of the grooves 2 is 1% of the outer diameter of the pile body 1. The maximum width to depth ratio of the grooves 2 is 5:1. The pile body 1 is a prestressed concrete pipe pile.

[0069] Example 8: A biomimetic pile with engraved fractal texture, comprising a pile body 1; wherein, the outer surface of the pile body 1 is provided with a plurality of grooves 2; and biomimetic texture grooves 3 are provided inside the grooves 2. The shapes of the biomimetic texture grooves 3 include Sierpinski triangles, root-like branching networks, and Cantor dust, that is, biomimetic texture grooves of Sierpinski triangles, root-like branching networks, and Cantor dust are provided on the pile body 1. The depth of the grooves 2 is 2.5% of the outer diameter of the pile body 1. The ratio of the maximum width to the depth of the grooves 2 is between 2:1. The pile body 1 is a composite material pile.

[0070] Example 9: A biomimetic pile with engraved fractal texture, comprising a pile body 1; wherein, a plurality of grooves 2 are formed on the outer surface of the pile body 1; and biomimetic texture grooves 3 are formed inside the grooves 2. The shape of the biomimetic texture grooves 3 is a network of branching branches resembling tree roots. The depth of the grooves 2 is 1% of the outer diameter of the pile body 1. The maximum width to depth ratio of the grooves 2 is 3:1. The pile body 1 is a prestressed concrete pipe pile.

[0071] The manufacturing method of the biomimetic pile with engraved fractal texture in Examples 1-9 above, such as Figure 3 The steps shown are as follows:

[0072] Step 1: Mold preparation;

[0073] Based on the predetermined engraved fractal texture pattern design, the corresponding raised fractal pattern is processed on the inner wall of the pile mold through CNC engraving, 3D printing or precision casting processes.

[0074] Step two: Concrete pouring and vibration;

[0075] A steel reinforcement framework is arranged inside the mold with the prepared raised fractal pattern. Concrete is then poured and thoroughly vibrated to ensure that the concrete completely fills the mold cavity and forms a dense structure. Specifically:

[0076] 21) Reinforcing bar cage layout: The layout of the reinforcing bar cage must strictly follow the design drawings to ensure that the specifications, spacing, protective layer thickness and lap length of the reinforcing bars meet the specifications. When installing in the mold, spacers or brackets should be used to fix the reinforcing bars to prevent displacement during the pouring process.

[0077] 22) Concrete pouring: Concrete shall be poured in layers according to the design mix proportion and in a uniform manner. The thickness of each layer shall not exceed 1.25 times the length of the vibrating rod. During the pouring process, the slump and fluidity of the concrete shall be controlled to avoid segregation.

[0078] 23) Vibration operation: Use an immersion vibrator and follow the principle of quick insertion and slow withdrawal. The spacing between vibration points should be less than 1.5 times the effective radius of the vibrator. In key areas, including areas with dense reinforcement and around embedded parts, the vibration time should be extended until the surface is covered with slurry and no air bubbles escape.

[0079] Step 3: Curing and demolding;

[0080] After the concrete is poured, it undergoes standard curing. Once the concrete reaches the specified strength, it is demolded. After demolding, the surface of the pile body forms an inwardly recessed fractal texture corresponding to the raised fractal pattern on the inner wall of the mold; specifically:

[0081] 31) Curing conditions and time: The concrete should be covered and watered within 1 to 2 hours after pouring to keep the surface moist; if the temperature is below 5℃, it should be covered with straw bags for insulation. The curing time should be based on 30% of the strength after 28 days of curing under standard conditions of 20±2℃ and relative humidity above 95% as the basis for demolding.

[0082] 32) Side formwork removal: When removing the side formwork, the concrete strength must ensure that the surface and edges of the pile are not damaged. After removal, the formwork should be cleaned in time and stacked neatly to avoid being stacked on the freshly poured pile. After the formwork is removed, the appearance quality of the pile should meet the requirements, with a flat and dense surface, a corner chipping depth of less than 10mm, a local honeycomb defect area of ​​less than 0.5% of the total surface area of ​​the pile, a shrinkage crack depth of no more than 20mm and a width of no more than 0.15mm, a transverse crack length of less than 1 / 2 of the side length, and no honeycomb, pitting or cracks at the top and tip of the pile.

[0083] 33) Removal of end formwork for inter-compartment: The removal of end formwork for inter-compartment should also be carried out when the concrete strength reaches 30% of the standard strength after 28 days of curing. The operation procedure is the same as that for side formwork removal.

[0084] 34) Overlapping fabrication and lifting and transportation: If it is necessary to overlap the upper piles after demolding, the lower pile body shall be used as the bottom mold. The number of overlapping layers shall be less than 4. The pile body shall be lifted after the concrete strength reaches 70% of the design value. The lifting points shall be set according to the design specifications and padded. Transportation shall be carried out when the strength reaches 100%.

[0085] Step four, surface treatment;

[0086] After demolding, the engraved fractal texture on the pile body is deburred and moistened for curing, thus obtaining the biomimetic pile with engraved fractal texture; specifically:

[0087] 41) Deburring treatment: After demolding, first clean the burrs on the engraved fractal texture of the pile body. Use a fine chisel or wire brush to gently remove loose particles, sharp edges and micro-cracks on the concrete surface caused by demolding, so as to avoid damaging the engraved fractal texture structure. When operating, it is necessary to follow the texture direction to prevent the scratches from expanding or the edges from cracking.

[0088] 42) Moistening and curing implementation: Moistening and curing should be carried out immediately after deburring to ensure that the concrete hydration reaction is sufficient. Spray water or cover with wet burlap or straw mats to keep the surface of the pile continuously moist. The curing time should not be less than 7 days. During this period, direct sunlight and wind drying should be avoided. The humidity should be maintained above 90% and the temperature should not be lower than 5℃.

[0089] 43) Surface defect inspection and repair: During the curing process, it is necessary to check whether there are defects such as mud inclusion, exposed reinforcement or insufficient strength in the engraved fractal texture. If mud inclusion or insufficient strength is found in the area, it is necessary to chisel it down to the depth of the fresh concrete surface layer 10-15cm, clean the reinforcement and pour C35 concrete. If the main reinforcement is exposed or broken, it is necessary to repair it by double-sided lap welding or pouring concrete.

[0090] 44) Post-curing treatment: After the curing period, remove surface residues and perform final cleaning of the engraved fractal texture. If decorative or protective treatment is required, apply concrete protectant, but ensure that the surface is completely dry and free of dust.

[0091] Application Example 1: The pile body 1 of the biomimetic pile with engraved fractal texture in Example 9 is cylindrical. On its entire outer surface, a continuous, inwardly recessed network texture resembling tree roots with branching branches is prefabricated. The groove 2 of this texture has a depth of 5mm, which is 1% of the pile diameter of 500mm. The groove width is 15mm, and the width-to-depth ratio is 3:1. The characteristic scale of the pattern, i.e., the width of the minimum branch, is not less than 5mm to ensure the compactness of the concrete pouring and the mechanical effectiveness of the texture. The manufacturing method is as follows: First, a pile mold is made using high-strength alloy steel. Based on the three-dimensionally designed fractal pattern resembling tree roots... The process involves using a five-axis CNC engraving machine to precisely machine corresponding raised patterns onto the inner wall of the pile mold; then, a prestressed steel reinforcement skeleton is installed inside the mold, and C80 high-strength concrete is poured. A high-frequency attached vibrator is used to ensure that the concrete flows densely and without air bubbles within the complex fractal mold cavity; subsequently, steam curing is performed to accelerate the strength development of the concrete. After curing, the pile is demolded, resulting in a concrete pile with a clear and complete engraved fractal texture on the surface. Through pull-out tests in a large model trench, under the same sandy soil conditions, the pull-out bearing capacity of the pile in this embodiment is 2.8 times that of a pile with a smooth surface of the same size.

[0092] Application Example 2: The biomimetic pile with engraved fractal texture in Example 3 uses laser engraving technology to process spaced fractal texture bands based on the Koch curve on the outer surface of the steel pipe. The texture bands are arranged at 300mm intervals along the axial direction of the pile body. Corrosion protection is achieved through surface zinc diffusion treatment. This design ensures a significant improvement in pull-out resistance while taking into account pile driving efficiency and economy. The principle of this device is clear, the manufacturing process is feasible, and it can be realized by upgrading and transforming the existing precast pile production line. The product is widely used in high-rise buildings, bridge piers, ports and docks, offshore wind power, transmission tower foundations, and major projects with high requirements for seismic resistance and pull-out resistance, and has huge market prospects and engineering value.

[0093] Obviously, the above embodiments are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description; it is neither necessary nor possible to exhaustively list all possible implementations; however, obvious variations or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A biomimetic pile with engraved fractal texture, comprising a pile body (1); characterized in that: The outer surface of the pile body (1) is provided with several grooves (2); the interior of the grooves (2) is provided with several biomimetic texture grooves (3).

2. The biomimetic pile with engraved fractal texture according to claim 1, characterized in that: The shape of the biomimetic texture groove (3) includes one or more of the following: the Sierpinski triangle, the Koch curve, the root-like bifurcation network, the Mandelbrot boundary line, or the Cantor dust.

3. The biomimetic pile with engraved fractal texture according to claim 1, characterized in that: The depth of the groove (2) is 1% to 5% of the outer diameter of the pile body (1), and the ratio of the maximum width to the depth of the groove is between 1:1 and 5:

1.

4. The biomimetic post with engraved fractal texture according to claim 1 or 3, characterized in that: The feature size of the biomimetic texture groove (3) is not less than 5mm.

5. The biomimetic pile with engraved fractal texture according to claim 1, characterized in that: The pile body (1) is a prestressed concrete pipe pile, solid square pile, steel pipe pile or composite material pile.

6. A method for manufacturing a biomimetic pile with engraved fractal texture as described in any one of claims 1-5, characterized in that... Includes the following steps: Step 1: Mold preparation; Based on the predetermined engraved fractal texture pattern design, the corresponding raised fractal pattern is processed on the inner wall of the pile mold through CNC engraving, 3D printing or precision casting processes. Step two: Concrete pouring and vibration; Arrange a steel reinforcement skeleton inside the mold with the raised fractal pattern, pour concrete and vibrate it thoroughly to ensure that the concrete completely fills the mold cavity and forms a dense shape. Step 3: Curing and demolding; After the concrete is poured, it is cured according to standard. After the concrete reaches the specified strength, it is demolded. After demolding, the surface of the pile body forms an inwardly recessed fractal texture that corresponds to the raised fractal pattern on the inner wall of the mold. Step four, surface treatment; After demolding, the engraved fractal texture of the pile body is deburred and moistened for curing to obtain the engraved fractal texture bionic pile.

7. The manufacturing method of the biomimetic pile with engraved fractal texture according to claim 6, characterized in that: The concrete pouring and vibration in step two are specifically as follows: 21) Reinforcing bar cage layout: The layout of the reinforcing bar cage must strictly follow the design drawings to ensure that the specifications, spacing, protective layer thickness and lap length of the reinforcing bars meet the specifications. When installing in the mold, spacers or brackets should be used to fix the reinforcing bars to prevent displacement during the pouring process. 22) Concrete pouring: Concrete shall be poured in layers according to the design mix proportion and in a uniform manner. The thickness of each layer shall not exceed 1.25 times the length of the vibrating rod. During the pouring process, the slump and fluidity of the concrete shall be controlled to avoid segregation. 23) Vibration operation: Use an immersion vibrator and follow the principle of quick insertion and slow withdrawal. The spacing between vibration points should be less than 1.5 times the effective radius of the vibrator. In key areas, including areas with dense reinforcement and around embedded parts, the vibration time should be extended until the surface is covered with slurry and no air bubbles escape.

8. The manufacturing method of the biomimetic pile with engraved fractal texture according to claim 6, characterized in that: The curing and demolding of the molded body in step three is as follows: 31) Curing conditions and time: The concrete should be covered and watered within 1 to 2 hours after pouring to keep the surface moist. When the temperature is low, below 5℃, it is necessary to cover it with straw bags for insulation. The curing time is based on the strength of 30% after 28 days of curing under standard conditions of temperature 20±2℃ and relative humidity above 95%. 32) Side formwork removal: When removing the side formwork, the concrete strength must ensure that the surface and edges of the pile are not damaged. After removal, the formwork should be cleaned in time and stacked neatly to avoid being stacked on the freshly poured pile. After the formwork is removed, the appearance quality of the pile should meet the requirements, with a flat and dense surface, a corner chipping depth of less than 10mm, a local honeycomb defect area of ​​less than 0.5% of the total surface area of ​​the pile, a shrinkage crack depth of no more than 20mm and a width of no more than 0.15mm, a transverse crack length of less than 1 / 2 of the side length, and no honeycomb, pitting or cracks at the top and tip of the pile. 33) Removal of end formwork for inter-compartment: The removal of end formwork for inter-compartment should also be carried out when the concrete strength reaches 30% of the standard strength after 28 days of curing. The operation procedure is the same as that for side formwork removal. 34) Overlapping fabrication and lifting and transportation: If it is necessary to overlap the upper piles after demolding, the lower pile body shall be used as the bottom mold. The number of overlapping layers shall be less than 4. The pile body shall be lifted after the concrete strength reaches 70% of the design value. The lifting points shall be set according to the design specifications and padded. Transportation shall be carried out when the strength reaches 100%.

9. The manufacturing method of the biomimetic pile with engraved fractal texture according to claim 6, characterized in that: The surface treatment in step four specifically involves: 41) Deburring treatment: After demolding, first clean the burrs on the engraved fractal texture of the pile body. Use a fine chisel or wire brush to gently remove loose particles, sharp edges and micro-cracks on the concrete surface caused by demolding, so as to avoid damaging the engraved fractal texture structure. When operating, it is necessary to follow the texture direction to prevent the scratches from expanding or the edges from cracking. 42) Moistening and curing implementation: Moistening and curing should be carried out immediately after deburring to ensure that the concrete hydration reaction is sufficient. Spray water or cover with wet burlap or straw mats to keep the surface of the pile continuously moist. The curing time should not be less than 7 days. During this period, direct sunlight and wind drying should be avoided. The humidity should be maintained above 90% and the temperature should not be lower than 5℃. 43) Surface defect inspection and repair: During the curing process, it is necessary to check whether there are defects such as mud inclusion, exposed reinforcement or insufficient strength in the engraved fractal texture. If mud inclusion or insufficient strength is found in the area, it is necessary to chisel it down to the depth of the fresh concrete surface layer 10-15cm, clean the reinforcement and pour C35 concrete. If the main reinforcement is exposed or broken, it is necessary to repair it by double-sided lap welding or pouring concrete. 44) Post-curing treatment: After the curing period, remove surface residues and perform final cleaning of the engraved fractal texture. If decorative or protective treatment is required, apply concrete protectant, but ensure that the surface is completely dry and free of dust.

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