Layered variable-pitch bionic scale steel pile and mounting method thereof
By setting layered variable-pitch shear components on the outer wall of the steel pile body, the problem of excessive slippage of the steel pile under high normal stress was solved, and the pull-out performance and bearing capacity of the steel pile under different soil conditions were improved.
Patent Information
- Application Number
- CN202511967008.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-24
- Publication Date
- 2026-03-03
AI Technical Summary
In the existing technology, under high normal stress, existing steel piles are prone to "overslipping," which leads to a decrease in shear resistance and a decline in pull-out performance.
A layered, variable-pitch biomimetic scale steel pile is designed. By setting shear-resistant component one, shear-resistant component two, and shear-resistant component three on the outer wall of the steel pile body, the spacing of the shear keys gradually changes according to the layers to adapt to the normal stress of different soil layers, avoid excessive slippage, and increase shear resistance.
It significantly improves the pull-out resistance and bearing capacity of steel piles, ensures uniform stress distribution on steel piles, and enhances pull-out resistance under different soil conditions.
Smart Images
Figure CN121593467A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of pile foundation engineering technology, and relates to a layered variable-pitch biomimetic scale steel pile and its installation method. Background Technology
[0002] Steel piles are steel structural members that are driven deep into the soil or rock layers to transfer the loads of the superstructure, such as buildings, bridges, or docks, to deeper, more solid strata, thus ensuring the stability and safety of the superstructure. Steel piles possess excellent compressive, bending, and tensile strength, capable of withstanding vertical or horizontal loads and providing stable support. Steel piles mainly include tubular steel piles and H-beam steel piles. Tubular steel piles have a circular cross-section, while H-beam steel piles have an H-shaped cross-section. Because tubular steel piles have a closed cross-section, their bending stiffness is the same in all directions, resulting in better bearing capacity and stability, and therefore they are more widely used.
[0003] Traditional tubular steel piles have relatively smooth outer surfaces. When driven into the soil, the friction between the steel pile and the soil is limited, resulting in insufficient bearing capacity, especially in loose sandy soil where their pull-out resistance is poor. This makes them unsuitable for pile foundation projects requiring high bearing capacity and pull-out resistance, such as offshore wind power foundations, port and dock engineering, and high-rise building foundations. To improve the bearing capacity and pull-out resistance of steel piles, researchers have designed a new type of steel pile. This new steel pile includes a main body and multiple layers of continuous, densely packed protrusions along its axial direction on the outer wall of the main body. These protrusions bear shear stress when the steel pile is subjected to pull-out force; therefore, they are commonly referred to as shear keys. When the steel pile is embedded in the soil, the shear keys interlock with the surrounding soil. When the steel pile is subjected to an upward pull-out force, the shear keys "hook" into the surrounding soil. Simultaneously, the sand particles between adjacent layers of shear keys undergo compression, rolling, and misalignment to dissipate the pull-out force, thereby achieving good pull-out resistance.
[0004] However, as the depth of the steel pile driven into the soil increases, the normal stress on the pile, i.e., the stress perpendicular to the outer wall of the pile, also gradually increases. Under high normal stress, the continuous and dense shear keys can cause "overslip" of the sand particles. "Overslip" refers to the phenomenon where, under high normal stress (typically greater than 150 kPa but less than 200 kPa), the sand particles are forcibly compressed by the continuous and dense shear keys, causing excessive constraint between adjacent shear key layers, preventing normal rearrangement. The enormous pull-out force "crushes" or "highly oriented" the extremely thin layer of soil particles adhering to the outer surface of the shear keys, ultimately forming a slip layer. This slip layer causes the soil to slide relative to the shear keys along their outer surface, rather than effectively engaging with them. Therefore, "overslip" actually reduces the shear resistance of the steel pile, leading to a decrease in its pull-out resistance. Summary of the Invention
[0005] The purpose of this invention is to provide a layered variable-pitch biomimetic scale steel pile and its installation method, in order to solve the technical problem that existing steel piles, under high normal stress conditions, exhibit "overslip phenomenon" and form a slip layer, which reduces shear resistance and leads to a decrease in the pull-out performance of the steel pile.
[0006] To achieve the above objectives, the present invention provides a specific technical solution for a layered variable-pitch biomimetic scale steel pile as follows: A layered variable-pitch biomimetic scale steel pile includes a steel pile body, a shear-resistant component one, a shear-resistant component two, and a shear-resistant component three; the shear-resistant component one, the shear-resistant component two, and the shear-resistant component three are sequentially arranged on the outer wall of the steel pile body along the axial direction of the steel pile body; each of the shear-resistant component one, the shear-resistant component two, and the shear-resistant component three includes a plurality of shear keys arranged along the axial direction of the steel pile body, and each shear key is arranged circumferentially along the steel pile body; In shear component one, the spacing between adjacent shear keys is equal; in shear component three, the spacing between adjacent shear keys is equal; in shear component two, the spacing between adjacent shear keys gradually increases from the end closer to shear component one to the end closer to shear component three, and satisfies the following relationship: ,in, The spacing between adjacent shear keys in the shear-resistant component is given. The spacing between adjacent shear keys in the second shear-resistant component is given. The spacing between adjacent shear keys in the three shear-resistant components is given.
[0007] Furthermore, the shear key is annular; the cross-section of the shear key is a right triangle, the first right-angled side of the right triangle is arranged radially along the main body of the steel pile, and the hypotenuse of the right triangle is located below the first right-angled side.
[0008] Furthermore, the shear key is composed of multiple spaced shear blocks, and the shear blocks of two adjacent shear keys are staggered along the circumference of the steel pile body; the cross-sectional shape of the shear block is a right triangle, the first right-angled side of the right triangle is arranged radially along the steel pile body, and the hypotenuse of the right triangle is located below the first right-angled side.
[0009] Furthermore, in the first shear component, the ratio of the spacing between adjacent shear keys to the first right-angled side is 2; in the second shear component, the ratio of the spacing between adjacent shear keys to the first right-angled side is 2 to 4; and in the third shear component, the ratio of the spacing between adjacent shear keys to the first right-angled side is 4.
[0010] Furthermore, the angle between the hypotenuse of the right triangle and the axis of the steel pile body is 25° to 35°.
[0011] Furthermore, the ratio of the length of the first shear-resistant component to the length of the main body of the steel pile is 0 to 0.375; the ratio of the length of the second shear-resistant component to the length of the main body of the steel pile is 0.375 to 0.625.
[0012] Furthermore, the shear-resistant component one, the shear-resistant component two, and the shear-resistant component three each also include two arc-shaped plates and clamps, with the shear key located on the outer wall of the arc-shaped plate; the inner wall of the arc-shaped plate matches the shape of the outer wall of the steel pile body; and the two arc-shaped plates are fixed to the outer wall of the steel pile body by the clamps.
[0013] Furthermore, a groove is provided on the outer wall of the steel pile body, and the groove is arranged along the circumference of the steel pile body; a protrusion is provided on the inner wall of the arc-shaped plate to cooperate with the groove.
[0014] Furthermore, the main body of the steel pile is made of Q345 steel, and the shear key is made of stainless steel or galvanized steel.
[0015] This invention also provides a method for installing a layered, variable-pitch biomimetic scale steel pile, comprising the following steps: S1. Based on the geological survey results, determine the shallow, middle and deep sections of the soil, and determine the spacing of the shear keys in the shear-resistant component one, the shear-resistant component two and the shear-resistant component three respectively; S2. The shear-resistant component one, the shear-resistant component two, and the shear-resistant component three are respectively installed on the steel pile body to form a biomimetic scale steel pile, wherein the shear-resistant component one is the same length as the shallow section, the shear-resistant component two is the same length as the middle section, and the shear-resistant component three is the same length as the deep section. S3. Drive the biomimetic scale steel pile into the soil, with the first shear component located in the shallow section, the second shear component located in the middle section, and the third shear component located in the deep section.
[0016] The layered variable-pitch biomimetic scale steel pile and its installation method of the present invention have the following advantages: The present invention relates to a layered, variable-pitch biomimetic scale steel pile. Shear-resistant component one is embedded in the shallow soil layer, shear-resistant component two in the middle soil layer, and shear-resistant component three in the deep soil layer. As the depth of the steel pile increases, the spacing of the shear keys in the shear-resistant components also increases, resulting in the largest spacing of the shear keys in shear-resistant component three. In the deep soil layer, under high normal stress conditions (greater than 150 kPa and less than 200 kPa), the larger shear key spacing provides sufficient rearrangement space for sand particles, preventing excessive slippage and allowing the shear keys to interlock with the soil, increasing the shear resistance on the steel pile and improving its pull-out performance. Conversely, the smallest spacing of the shear keys in shear-resistant component one allows the steel pile to primarily bear pull-out forces in the shallow soil layer (greater than 0 kPa and less than 100 kPa). The smaller shear key spacing provides a near-continuous supporting friction surface for the sand particles, increasing the frictional resistance between the shear keys and the soil, thereby significantly improving pull-out performance. Furthermore, this design allows the spacing of the shear keys in the second shear component to gradually increase. This gradual design matches the spacing of the shear keys with the soil middle layer where the normal stress is 100kPa to 150kPa, avoiding stress concentration caused by abrupt changes in spacing and achieving a smooth transition in stiffness and strength. As a result, the steel piles in this transition zone can balance their pull-out resistance and bearing capacity, ensuring the uniformity of stress on the all-steel piles. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the layered variable-pitch biomimetic scale steel pile of the present invention; Figure 2 for Figure 1 A magnified view of a portion of the image; Figure 3 This is a schematic diagram of the steel pile body and shear-resistant components of the present invention; Figure 4 This is a schematic diagram of the arc-shaped plate and shear key of the present invention; Figure 5 This is a schematic diagram of the arc-shaped plate and shear key according to another embodiment of the present invention; Figure 6 This is a flowchart illustrating the installation method of the layered variable-pitch biomimetic scale steel pile of the present invention.
[0018] Figure label: 1. Steel pile body; 11. Groove; 2. Shear component one; 21. Shear key; 211. Shear block; 23. Curved plate; 24. Clamp; 25. Protrusion; 3. Shear component two; 4. Shear component three. Detailed Implementation
[0019] The technical solutions of this application will now be described clearly and in detail with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, "multiple" refers to two or more. The terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.
[0020] like Figure 1 and Figure 2 As shown, this invention provides a layered, variable-pitch biomimetic scale steel pile, comprising a steel pile body 1, a shear-resistant component 2, a shear-resistant component 3, and a shear-resistant component 4. Shear-resistant components 2, 3, and 4 are sequentially arranged on the outer wall of the steel pile body 1 along its axial direction. Each of the shear-resistant components 2, 3, and 4 includes multiple shear keys 21 arranged along the axial direction of the steel pile body 1, with each shear key 21 arranged circumferentially around the steel pile body 1. The spacing between adjacent shear keys 21 in shear-resistant component 2 is equal, the spacing between adjacent shear keys 21 in shear-resistant component 4 is equal, and the spacing between adjacent shear keys 21 in shear-resistant component 3 gradually increases from the end closer to shear-resistant component 2 to the end closer to shear-resistant component 4, satisfying the following relationship: ,in, The spacing between adjacent shear keys 21 in shear component 2. The spacing between adjacent shear keys 21 in shear component 23. The spacing between adjacent shear keys 21 in shear component 3 4.
[0021] When a steel pile is embedded in the soil and pulled upwards, due to the presence of shear keys 21, the pile primarily bears the downward pull-out resistance from the soil and the normal stress perpendicular to the outer wall of the pile. The pull-out resistance reflects the pile's pull-out performance, while the normal stress reflects its bearing capacity. When the pile is shallowly embedded, the normal stress is relatively small, and the force acting on the pile is mainly pull-out resistance. As the pile's embedment depth increases, the normal stress also increases. At a certain depth, the force acting on the pile is dominated by normal stress. By setting the spacing of the shear keys 21 at different embedment depths, the pull-out performance and bearing capacity of the steel pile can be balanced.
[0022] In the layered variable-pitch biomimetic scale steel pile of this invention, shear-resistant components 1-2, 2-3, and 3-4 are provided on the outer wall of the steel pile body 1. Shear-resistant component 1-2 is buried in the shallow soil layer, shear-resistant component 2-3 is buried in the middle soil layer, and shear-resistant component 3-4 is buried in the deep soil layer. As the depth of the steel pile body 1 increases, the spacing of the shear keys 21 in the shear-resistant components also increases, making the spacing of the shear keys 21 in the shear-resistant component 3-4 the largest. In the deep soil layer, i.e., under high normal stress conditions greater than 150 kPa and less than 200 kPa, the larger spacing of the shear keys 21 can provide sufficient rearrangement space for sand particles, avoid excessive slippage, and make the shear keys 21 interlock with the soil, increasing the shear resistance of the steel pile and improving the pull-out performance of the steel pile. Furthermore, by minimizing the spacing of the shear keys 21 in shear-resistant component 2, the steel pile primarily bears the uplift force in the shallow soil layer (i.e., under low normal stress conditions greater than 0 kPa and less than 100 kPa). The smaller spacing of the shear keys 21 provides a near-continuous support friction surface for the sand particles, increasing the frictional resistance between the shear keys 21 and the soil, thereby significantly improving the uplift resistance. Conversely, the spacing of the shear keys 21 in shear-resistant component 3 gradually increases. This gradual design matches the spacing of the shear keys 21 with the soil layer where the normal stress is between 100 kPa and 150 kPa, avoiding stress concentration caused by abrupt spacing changes. This achieves a smooth transition in stiffness and strength, allowing the steel pile in this transition zone to balance uplift and bearing capacity, ensuring uniform stress distribution in the all-steel pile.
[0023] In some embodiments of the present invention, the ratio of the spacing between adjacent shear keys 21 in shear-resistant component three 4 to the spacing between adjacent shear keys 21 in shear-resistant component one 2 is 2. The ratio of the minimum spacing between adjacent shear keys 21 in shear-resistant component two 3 to the spacing between adjacent shear keys 21 in shear-resistant component one 2 is 2. The ratio of the maximum to the minimum spacing between adjacent shear keys 21 in shear component 23 is _____. , , The minimum spacing between adjacent shear keys 21 in shear component 23 is the spacing between the two adjacent shear keys 21 closest to shear component 12, and the maximum spacing between adjacent shear keys 21 in shear component 23 is the spacing between the two adjacent shear keys 21 closest to shear component 34.
[0024] In some embodiments of the present invention, such as Figure 2 and Figure 3 As shown, the shear key 21 is annular. The cross-section of the shear key 21 is a right triangle. The first right-angled side of the right triangle is radially arranged along the main body of the steel pile 1, and the hypotenuse of the right triangle is located on the side of the first right-angled side facing the direction in which the steel pile is driven into the soil. The second right-angled side of the right triangle is axially arranged along the main body of the steel pile 1. The cross-section of the shear key 21 is similar to a cone or wedge with the apex pointing downwards.
[0025] In this embodiment, since the cross-section of the shear key 21 is a right-angled triangle with the upper end larger than the lower end, when the steel pile is pulled upwards, the upper end of the shear key 21 hooks into the soil, causing the soil to wedge tightly into the upper end of the shear key 21, generating a large hooking force, i.e., shear resistance, thereby improving the pull-out resistance of the steel pile. When the steel pile is pressed downwards, because the lower end of the shear key 21 is smaller and the local stress is high, it is easy to slip, and the soil can slide along the inclined surface of the shear key 21, facilitating the driving of the steel pile into the soil. Therefore, the shear key 21 of the shear-resistant component can maximize the utilization of the directional strength difference of the shear key 21, significantly improving the pull-out resistance and facilitating the driving of the steel pile into the soil. Furthermore, the shear key 21 in this embodiment is a continuous structure that can mimic the alignment structure of snake scales. It has strong overall structural integrity and can significantly increase the local stiffness of the steel pile at this cross-section. It can evenly adjust the frictional resistance of the steel pile body 1 in all directions, making it suitable for relatively soft soil or pile foundation projects that require stiffness of the steel pile body 1.
[0026] In some embodiments of the present invention, such as Figure 2 and Figure 5 As shown, the shear key 21 is composed of multiple shear blocks 211 spaced apart, with the shear blocks 211 of two adjacent shear keys 21 staggered along the circumference of the steel pile body 1. The cross-sectional shape of the shear block 211 is a right triangle, with the first right-angled side of the right triangle arranged radially along the steel pile body 1, and the hypotenuse of the right triangle located on the side of the first right-angled side in the direction of the steel pile being driven into the soil.
[0027] In this embodiment, the effect of the cross-sectional shape of the shear key 21 is the same as in the above embodiment, and will not be repeated. The shear key 21 in this embodiment adopts a dispersed structure, which can mimic the staggered structure of fish scales. The discrete shear blocks 211 allow the soil to undergo a certain degree of "flow around" and local shearing between the shear blocks 211, resulting in better pile driving effect. Each shear block 211 can independently adjust the bearing capacity of the soil, which is suitable for hard soil and dense soil, or pile foundation projects with requirements on pile driving depth.
[0028] In some embodiments of the present invention, such as Figure 2 As shown, the distance between adjacent shear keys 21 is The length of the first leg of the right triangle is Then the distance between adjacent shear keys 21 in shear component 2 is... The length of the first right-angled side in shear component 2 is ,and The ratio relationship in this embodiment applies to situations where the steel pile is embedded in ordinary soil at a depth of less than 7.5m, and the normal stress on the steel pile is between 0kPa and 100kPa. This is because the normal stress on the steel pile is relatively small at this time, and the pull-out resistance is the main factor. By reducing the spacing of the shear keys 21 in the shear-resistant component 2, the lower ends of the multiple shear keys 21 provide a continuous and uniform friction surface, which improves the pull-out resistance of the steel pile and thus improves the pull-out performance of the steel pile.
[0029] In some embodiments of the present invention, the distance between adjacent shear keys 21 in the shear-resistant component 3 4 is The length of the first leg of the right triangle in shear component 3 is 4. ,and The ratio in this embodiment applies to situations where steel piles are embedded in ordinary soil at a depth greater than 12.5m, and the normal stress on the steel piles is greater than 150kPa but less than 200kPa. This is because the normal stress on the steel piles is relatively large at this point, and the normal stress is dominant. To prevent excessive slippage, the ratio is set to be larger, i.e., the distance between adjacent shear keys 21 is larger. This allows sufficient space between adjacent shear keys 21, enabling sand particles to rearrange under high pressure. The sand particles can "fill" the gaps between the shear keys 21, forming a "toothed" structure. The upper end of each shear key 21 can independently perform a "soil-moving" function, rather than sliding as a whole. The soil in the gaps forms "shear bonds," improving the overall shear strength. Experiments have shown that under a high normal stress of 200kPa, in At that time, when the shear keys 21 were continuously and densely arranged, the measured shear force was 129.71 kPa. At that time, the measured shear force was 158.12 kPa. Compared with the shear keys 21 continuously and densely arranged in the prior art, the shear force of the shear key 21 in the shear component 3 4 in this embodiment is increased by 21.9%, which fully proves the effectiveness of the appropriate spacing to avoid excessive slippage.
[0030] In some embodiments of the present invention, the distance between adjacent shear keys 21 in the shear-resistant component 2 3 is... The length of the first leg of the right triangle in shear component 23 is... ,and In this embodiment, the ratio in shear-resistant component 3 increases with the depth of the steel pile embedded in the soil. For example, at a depth of 7.5m, At a depth of 9m, At a depth of 10.5m, At a depth of 12.5m, In this embodiment, the gradual design of the spacing between adjacent shear keys 21 in the shear-resistant component 2 3 matches the working conditions of steel piles being buried in ordinary soil at a depth of 7.5m to 12.5m and a normal stress of 100kPa to 150kPa. This avoids stress concentration caused by abrupt changes in the spacing between adjacent shear keys 21, achieving a smooth transition in stiffness and strength. Thus, the pull-out resistance and bearing capacity can be balanced in this transition section, ensuring uniform stress distribution along the entire pile length.
[0031] In some embodiments of the present invention, such as Figure 2 As shown, the angle between the hypotenuse of the right triangle and the axis of the main body of the steel pile 1 The angle is between 25° and 35°. Preferably, the included angle is... It is 30°.
[0032] In this embodiment, the upper end of the shear key 21 is larger than the lower end, resulting in a higher shear strength at the upper end compared to the lower end. When the steel pile body 1 is subjected to an uplift load, the shear key 21 can maximize the utilization of the directional strength difference, significantly improving the uplift bearing capacity. Furthermore, research shows that when the angle between the hypotenuse of the right triangle and the axis of the steel pile body 1... At an angle of 30°, the pull-out bearing capacity is the highest, and the pull-out performance is the best. Experiments showed that under a normal stress of 200 kPa, and... When the steel pile is pulled upward, the shear strength at the upper end of the shear key 21 is 158.12 kPa, and when the steel pile is pressed downward, the shear strength at the lower end of the shear key 21 is 147.60 kPa. The difference between the two shear strengths is 10.52 kPa, which is 7.1%. This reflects the difference in directional strength of the shear key 21.
[0033] In some embodiments of the present invention, the steel pile body 1 is made of Q345 steel. Q345 steel is a steel with a yield strength of not less than 345 MPa, which has advantages such as high strength, high toughness, and low price, and can meet the usage requirements of the steel pile body 1. The shear key 21 is made of stainless steel or galvanized steel. Stainless steel has advantages such as excellent corrosion resistance, good high and low temperature performance, and aesthetics and durability. Galvanized steel has advantages such as excellent corrosion resistance, long service life, and low cost. Both stainless steel and galvanized steel can meet the usage requirements of the shear key 21.
[0034] In some embodiments of the present invention, such as Figure 1 , Figure 3 and Figure 4As shown, shear-resistant components 1 (2), 2 (3), and 3 (4) each include two arc-shaped plates 23 and clamps 24. Shear keys 21 are located on the outer surface of the arc-shaped plates 23. The inner wall of the arc-shaped plate 23 matches the shape of the outer wall of the steel pile body 1. The two arc-shaped plates 23 are fixed to the outer wall of the steel pile body 1 by clamps 24. At least two clamps 24 are used, located on the outer peripheral wall of the arc-shaped plates 23, making the two arc-shaped plates 23 more firmly fixed to the steel pile body 1. Each arc-shaped plate 23 can be formed by dividing a cylindrical body along the plane containing its axis. The shear keys 21 and the arc-shaped plates 23 can be integrally manufactured.
[0035] In this embodiment, the two arc-shaped plates 23 are spliced and fixed by clamps 24, which can modularize the shear-resistant components. This allows for quick disassembly and replacement of appropriate shear-resistant components according to different positions of the steel pile body 1, making it suitable for different usage environments and improving the adaptability and construction flexibility of the pile foundation.
[0036] In some embodiments of the present invention, such as Figure 3 , Figure 4 As shown, a groove 11 is provided on the outer wall of the steel pile body 1, and the groove 11 is arranged along the circumference of the steel pile body 1. A protrusion 25 that mates with the groove 11 is provided on the inner wall of the arc plate 23.
[0037] In this embodiment, when the arc plate 23 is installed on the steel pile body 1, the protrusion 25 on the arc plate 23 is inserted into the corresponding groove 11 on the steel pile body 1 to achieve axial positioning of the shear assembly and prevent it from axially moving after assembly, which would affect the bearing capacity and pull-out resistance of the steel pile body 1.
[0038] In some embodiments of the present invention, such as Figure 3 , Figure 4 As shown, there are multiple grooves 11 on the outer wall of the steel pile body 1, and they are arranged along the axial direction of the steel pile body 1. Correspondingly, there are multiple protrusions 25 on the inner wall of the arc plate 23, which are used to cooperate with the multiple grooves 11 on the steel pile body 1 to further improve the firmness of the shear-resistant component installation.
[0039] In some alternative embodiments of the present invention, a protrusion 25 may be provided on the outer wall of the steel pile body 1, and a groove 11 that cooperates with the protrusion 25 may be provided on the inner wall of the arc plate 23.
[0040] In some embodiments of the present invention, the ratio of the length of shear-resistant component 2 to the length of the steel pile body 1 is 0 to 0.375, and the ratio of the length of shear-resistant component 3 to the length of the steel pile body 1 is 0.375 to 0.625. The ratio of the length of each shear-resistant component to the length of the steel pile body 1 can be selected according to the actual geological conditions and engineering needs.
[0041] In some embodiments of the present invention, the design of a monopile foundation for an offshore wind power project is used as a basis for illustration. The steel pile body 1 has a length of 20m extending into the soil and a diameter of 2m. The first right-angled side of the right triangle of the shear key 21 is... mm, the hypotenuse of the right triangle of shear key 21 makes an angle of 30° with the axis of the steel pile body 1. The shallow section of the soil is located in the depth range of 0m to 7.5m, corresponding to soil with normal stress greater than 0kPa and less than 100kPa. The shear component 2 of the steel pile body 1 is of the same length as the shallow section, and in the shear component 2... The middle section of the soil lies at a depth of 7.5m to 7.5m, corresponding to soil with a normal stress greater than 100kPa and less than 150kPa. The shear component 23 of the steel pile body 1 is of the same length as the middle section. In shear component 23... And it increases with increasing depth. The deep section of the soil is located in the depth range of 12.5m to 20m, corresponding to soil with a normal stress greater than 150kPa and less than 200kPa. The shear component 34 of the steel pile body 1 is the same length as the deep section, and the shear component 34 contains... .
[0042] A simulation test was conducted on the steel pile. The simulation test was conducted under the same environment and scaled up proportionally. First, the bearing capacity and pull-out bearing capacity of the traditional smooth steel pile were obtained through the simulation test. Then, the bearing capacity and pull-out bearing capacity of the layered variable-pitch bionic scale steel pile were obtained through the simulation test. The test results show that compared with the traditional smooth steel pile, the bearing capacity of the bionic scale steel pile of this application is increased by 40% and the pull-out bearing capacity is increased by 60%.
[0043] This invention also provides a method for installing layered, variable-pitch biomimetic scale steel piles, such as... Figure 6 As shown, it includes the following steps: S1. Based on the geological survey results, determine the shallow, middle, and deep sections of the soil, and determine the spacing of shear keys 21 in shear component 1 (2), shear component 2 (3), and shear component 3 (4) respectively; wherein, the normal stress corresponding to the shallow section is 0 kPa to 100 kPa, the normal stress corresponding to the middle section is 100 kPa to 150 kPa, and the normal stress corresponding to the deep section is greater than 150 kPa and less than 200 kPa; S2. Shear-resistant component 1, shear-resistant component 2, and shear-resistant component 3 are respectively installed on the steel pile body 1 to form a biomimetic scale steel pile. Shear-resistant component 1 is the same length as the shallow section, shear-resistant component 2 is the same length as the middle section, and shear-resistant component 3 is the same length as the deep section. S3. Drive the biomimetic scale steel piles into the soil, with shear component 1 2 located in the shallow section, shear component 2 3 located in the middle section, and shear component 3 4 located in the deep section.
[0044] In the installation method of the layered variable-pitch biomimetic scale steel pile of this invention, shear-resistant components 1-2, 2-3, and 3-4 are set on the outer wall of the steel pile body 1. As the depth of the steel pile body 1 increases, the spacing of the shear keys 21 in the shear-resistant components also increases, making the spacing of the shear keys 21 in the shear-resistant component 3-4 the largest. In the deep soil layer, that is, under the high normal stress conditions of greater than 150 kPa and less than 200 kPa, the larger spacing of the shear keys 21 can provide sufficient rearrangement space for sand particles, avoid excessive slippage, and make the shear keys 21 interlock with the soil, increasing the shear resistance of the steel pile and improving the pull-out performance of the steel pile. Furthermore, by minimizing the spacing of the shear keys 21 in shear-resistant component 2, the steel pile primarily bears the uplift force in the shallow soil layer (i.e., under low normal stress conditions greater than 0 kPa and less than 100 kPa). The smaller spacing of the shear keys 21 provides a near-continuous support friction surface for the sand particles, increasing the frictional resistance between the shear keys 21 and the soil, thereby significantly improving the uplift resistance. Conversely, the spacing of the shear keys 21 in shear-resistant component 3 gradually increases. This gradual design matches the spacing of the shear keys 21 with the soil layer where the normal stress is between 100 kPa and 150 kPa, avoiding stress concentration caused by abrupt spacing changes. This achieves a smooth transition in stiffness and strength, allowing the steel pile in this transition zone to balance uplift and bearing capacity, ensuring uniform stress distribution in the all-steel pile.
[0045] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.
Claims
1. A layered, variable-pitch biomimetic scale steel pile, comprising a steel pile body, characterized in that, It also includes shear-resistant component one, shear-resistant component two, and shear-resistant component three; shear-resistant component one, shear-resistant component two, and shear-resistant component three are sequentially arranged on the outer wall of the steel pile body along the axial direction of the steel pile body; each of shear-resistant component one, shear-resistant component two, and shear-resistant component three includes multiple shear keys arranged along the axial direction of the steel pile body, and each shear key is arranged along the circumference of the steel pile body; In shear component one, the spacing between adjacent shear keys is equal; in shear component three, the spacing between adjacent shear keys is equal; in shear component two, the spacing between adjacent shear keys gradually increases from the end closer to shear component one to the end closer to shear component three, and satisfies the following relationship: ,in, The spacing between adjacent shear keys in the shear-resistant component is given. The spacing between adjacent shear keys in the second shear-resistant component is given. The spacing between adjacent shear keys in the three shear-resistant components is given.
2. The layered variable-pitch biomimetic scale steel pile according to claim 1, characterized in that, The shear key is annular; the cross-section of the shear key is a right triangle, the first right-angled side of the right triangle is arranged radially along the main body of the steel pile, and the hypotenuse of the right triangle is located on the side of the first right-angled side in the direction of the steel pile being driven into the soil.
3. The layered variable-pitch biomimetic scale steel pile according to claim 1, characterized in that, The shear key is composed of multiple spaced shear blocks, with the shear blocks of two adjacent shear keys being staggered along the circumference of the steel pile body; the cross-sectional shape of the shear block is a right triangle, with the first right-angled side of the right triangle arranged radially along the steel pile body, and the hypotenuse of the right triangle located on the side of the first right-angled side in the direction of the steel pile being driven into the soil.
4. The layered variable-pitch biomimetic scale steel pile according to claim 2 or 3, characterized in that, In the first shear component, the ratio of the spacing between adjacent shear keys to the first right-angled side is 2; in the second shear component, the ratio of the spacing between adjacent shear keys to the first right-angled side is 2 to 4; and in the third shear component, the ratio of the spacing between adjacent shear keys to the first right-angled side is 4.
5. The layered variable-pitch biomimetic scale steel pile according to claim 2 or 3, characterized in that, The angle between the hypotenuse of the right triangle and the axis of the main body of the steel pile is 25° to 35°.
6. The layered variable-pitch biomimetic scale steel pile according to claim 1, characterized in that, The ratio of the length of the first shear-resistant component to the length of the main body of the steel pile is 0 to 0.375; the ratio of the length of the second shear-resistant component to the length of the main body of the steel pile is 0.375 to 0.
625.
7. The layered variable-pitch biomimetic scale steel pile according to claim 1, characterized in that, Shear-resistant component one, shear-resistant component two, and shear-resistant component three each further include two arc-shaped plates and clamps. The shear key is located on the outer wall of the arc-shaped plate. The inner wall of the arc-shaped plate matches the shape of the outer wall of the steel pile body. The two arc-shaped plates are fixed to the outer wall of the steel pile body by the clamps.
8. The layered variable-pitch biomimetic scale steel pile according to claim 7, characterized in that, The outer wall of the steel pile body is provided with a groove, which is arranged along the circumference of the steel pile body; the inner wall of the arc plate is provided with a protrusion that cooperates with the groove.
9. The layered variable-pitch biomimetic scale steel pile according to claim 1, characterized in that, The main body of the steel pile is made of Q345 steel, and the shear key is made of stainless steel or galvanized steel.
10. A method for installing a layered, variable-pitch biomimetic scale steel pile according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Based on the geological survey results, determine the shallow, middle and deep sections of the soil, and determine the spacing of the shear keys in the shear-resistant component one, the shear-resistant component two and the shear-resistant component three respectively; S2. The shear-resistant component one, the shear-resistant component two, and the shear-resistant component three are respectively installed on the steel pile body to form a biomimetic scale steel pile, wherein the shear-resistant component one is the same length as the shallow section, the shear-resistant component two is the same length as the middle section, and the shear-resistant component three is the same length as the deep section. S3. Drive the biomimetic scale steel pile into the soil, with the first shear component located in the shallow section, the second shear component located in the middle section, and the third shear component located in the deep section.