Device and method for monitoring strength of stiff composite pile with spiral pile core based on nail shooting theory

Abstract

The invention provides a spiral pile core stiff composite pile strength monitoring device and method based on a nail shooting theory, relates to the technical field of pile strength detection, is used for detecting the strength of cemented soil of a pile body of a spiral pile core stiff composite pile, and specifically comprises an insertion cylinder assembly, at least one telescopic sleeve, a soil partition plate assembly, a telescopic power assembly and an anchoring nail shooting assembly. According to the invention, by designing the insertion cylinder assembly, the anchoring nail shooting assembly, the telescopic sleeve (in a storage state), the soil partition plate assembly, the telescopic power assembly and the anchoring nail shooting assembly can be protected in the link of arranging the insertion cylinder assembly, and the telescopic sleeve is unfolded before a nail shooting experiment; the telescopic power assembly drives the telescopic sleeve to transversely get close to the spiral pile core stiff composite pile, and a channel is formed between the insertion cylinder assembly and the spiral pile core stiff composite pile. Compared with a low strain method, a drilling sampling method and the like, the experiment mode has the advantages of being easy to operate and reliable in experiment result.

Description

Technical Field

[0001] This invention relates to the field of measuring the physical properties of materials, specifically to the field of pile strength testing technology, and more specifically to a device and method for monitoring the strength of helical pile core stiffness composite piles based on the nail-shooting theory. Background Technology

[0002] To address the limitations of traditional pile types in marine soft soil regions, the helical core-reinforced composite pile has emerged as an innovative solution that balances load-bearing capacity with low-carbon safety. Its construction method employs an integrated process of "helical drilling - reinforcement implantation - pressure grouting": First, a drill bit with helical blades rotates and cuts into the soft soil, utilizing the blades' soil removal function to minimize disturbance to the surrounding soil; then, a reinforcement core is implanted, forming a rigid framework for the pile; finally, cement-based grout is injected under high pressure into the soil around and at the pile tip through the drill bit's built-in grouting channel. The grout undergoes a physicochemical reaction with the soft soil, forming a solidified composite soil mass, which, together with the helical blades and reinforcement core, constitutes a synergistic load-bearing system of "core-blade-composite soil."

[0003] The helical core-reinforced composite pile adopts a multi-section construction process, with the pile body spliced ​​from multiple segments. Each segment has helical blades, which makes the pile body not a continuous and homogeneous whole. There are natural stiffness abrupt changes at the interfaces between the multiple segments. The presence of helical blades further exacerbates the complexity of the pile structure (the material and stiffness of the blades differ significantly from the main body of the pile). The helical distribution of the blades also creates periodic stiffness fluctuations. This discontinuous and variable stiffness structural characteristic directly makes traditional low-strain testing methods that rely on the assumption of a homogeneous and continuous pile body difficult to apply. (Due to the discontinuity of the interfaces between the multiple segments and the stiffness abrupt changes caused by the helical blades, stress waves undergo multiple reflections, refractions, and scattering during propagation. The reflected wave signals are chaotic. At the same time, the stiffness differences between the blades and the pile body, and at the segment interfaces, lack a unified pattern, making it impossible to form a reference low-strain spectrum feature library. This makes it difficult for technicians to interpret whether there are defects in the pile body, the location and extent of defects, and to effectively determine the integrity of the pile body.) Furthermore, because the helical blades of the helical core-reinforced composite pile are spirally arranged around the pile body, and the edges of the blades are tightly bonded to the surrounding soil or the internal core, forming a "mechanical obstruction," when the drilling equipment attempts to penetrate deep into the pile body, the blades directly obstruct the drill bit's path. This prevents the borehole from penetrating along the pile axis and allows only limited advancement within the gaps between the blades, failing to reach the concrete in the core area of ​​the pile body (the core requirement of the borehole sampling method is that the borehole can penetrate deep into the pile body and obtain a representative sample). Consequently, it is impossible to accurately assess the actual strength of the cement-soil mixture in the pile body through physical and mechanical property testing of the sample, severely restricting the judgment of the pile's bearing capacity. Therefore, a new, targeted testing method is urgently needed to overcome these technical bottlenecks. In view of this, we propose a device and method for monitoring the strength of the cement-soil mixture in the helical core-reinforced composite pile body based on the nail-driving theory. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a device and method for monitoring the strength of helical core-strength composite piles based on the nail-shooting theory, which solves the problem that traditional methods cannot detect the strength of cement-soil in the pile body of helical core-strength composite piles.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A strength monitoring device for helical pile core stiffness composite piles based on nail-driving theory includes:

[0007] Insert assembly;

[0008] At least one set of telescopic sleeves is provided on the side of the insert assembly, and a soil-separating plate assembly is installed at the end of the telescopic sleeve away from the insert assembly;

[0009] A telescopic power assembly is installed inside the insert assembly and is used to drive the telescopic sleeve to extend or retract.

[0010] An anchoring nail assembly, which is installed inside the insert assembly and is used to fire nails toward the telescopic sleeve;

[0011] A measurement module is used to measure the depth to which a nail is driven into a spiral core-reinforced composite pile.

[0012] Preferably, the insert assembly includes:

[0013] A cylindrical body, with a cone head fixedly installed at the bottom of the cylindrical body.

[0014] Preferably, a sleeve receiving tube is fixedly connected to the inner side wall of the cylinder, and a round opening is provided on the side wall of the cylinder corresponding to the end of the sleeve receiving tube;

[0015] The telescopic sleeve includes several axially slidably connected guide sleeves. The guide sleeve located at the first end of the telescopic sleeve is slidably engaged with the inner side of the sleeve receiving tube. A soil isolation plate assembly is installed at the end of the guide sleeve located at the second end of the telescopic sleeve.

[0016] The soil barrier assembly is provided with a clearance component.

[0017] Preferably, an L-shaped clamp is fixedly connected to the end of the guide sleeve located at the second end of the telescopic sleeve, and a notch is provided on the side of the soil isolation plate assembly.

[0018] Preferably, the yielding component includes:

[0019] A soil-retaining plate, with a window at one end of the soil-retaining plate;

[0020] A sliding plate, wherein a U-shaped opening is provided on one side of the sliding plate, the U-shaped opening is slidably engaged with the side of the window, and a first magnetic block is fixedly connected to the side of the window, and a second magnetic block is fixedly connected to the inside of the U-shaped opening.

[0021] At least one of the first magnetic block and the second magnetic block is an electromagnet.

[0022] Preferably, a flange is fixedly connected to the end of the sleeve receiving tube;

[0023] The telescopic power assembly includes: a linear drive assembly and a transmission rod. The linear drive assembly is fixedly connected to the inner wall of the cylinder. The telescopic end of the linear drive assembly is fixedly connected to the transmission rod. A guide hole is provided on the flange. The transmission rod is slidably engaged with the guide hole. The end of the transmission rod away from the linear drive assembly is fixedly connected to the inner wall of the guide sleeve located at the second end of the telescopic sleeve.

[0024] Preferably, the measurement module includes: a first distance sensor and a second distance sensor, both of which are fixedly connected to the flange. The first distance sensor is used to detect the distance to the helical core stiff composite pile body, and the second distance sensor is used to detect the distance to the end of the nail.

[0025] Preferably, the linear drive assembly is a flexible lifting assembly, the transmission rod is a multi-section telescopic hollow sleeve, and one end of the chain of the linear drive assembly is fixedly connected to the inner end of the transmission rod.

[0026] Preferably, the anchoring nail assembly is an automatic nail gun with a nail storage compartment.

[0027] The method for monitoring the strength of helical pile core-stiffness composite piles based on the nail-shooting theory, using the aforementioned nail-shooting theory-based helical pile core-stiffness composite pile strength monitoring device, specifically includes the following steps:

[0028] S1. Arrange the insert assembly:

[0029] Select a point 10-30cm outside the spiral core rigid composite pile, then connect the insert assembly to the pile driver, and use the pile driver to drive the insert assembly into the predetermined depth at the selected point, while always keeping the telescopic sleeve on the side of the insert assembly facing the spiral core rigid composite pile.

[0030] S2. Unfold the telescopic sleeve:

[0031] The telescopic power component is used to push the telescopic sleeve to move outward, and the soil in the area where the soil isolation plate component passes is pushed to both sides until the soil isolation plate component is in close contact with the outer side of the helical core rigid composite pile.

[0032] S3. Nail firing and calculation:

[0033] The anchoring nail assembly is activated, and the nails are fired into the helical core-reinforced composite pile along the direction of the telescopic sleeve. The depth of the nails driven into the helical core-reinforced composite pile is measured based on the measurement module.

[0034] The pile strength is evaluated by comparing the depth data of the driven helical core-reinforced composite pile with standard experimental data obtained in the laboratory.

[0035] This invention provides a device and method for monitoring the strength of helical pile core stiffness composite piles based on the nail-driving theory.

[0036] It has the following beneficial effects:

[0037] 1. This invention, through the design of a sleeve assembly, installs the anchoring nail assembly, telescopic sleeve (in the retracted state), soil isolation plate assembly, telescopic power assembly, and anchoring nail assembly inside the sleeve assembly. This provides protection for the anchoring nail assembly, telescopic sleeve (in the retracted state), soil isolation plate assembly, telescopic power assembly, and anchoring nail assembly during the sleeve assembly setup. Before the nail firing test, the telescopic sleeve is deployed, and the telescopic power assembly drives the telescopic sleeve laterally towards the helical pile core-reinforced composite pile, forming a channel between the sleeve assembly and the helical pile core-reinforced composite pile for the anchoring nail assembly to fire the nails for the experiment. The measurement module provides feedback on the depth of the nail penetration into the helical pile core-reinforced composite pile, and this data is compared with standard experimental data obtained in the laboratory to evaluate the pile strength. Compared with low strain testing and borehole sampling methods, this experimental method has the advantages of simple operation and reliable experimental results. Attached Figure Description

[0038] Figure 1 This is a model diagram of the helical pile core stiffness composite pile strength monitoring device based on the nail-driving theory proposed in this invention;

[0039] Figure 2 This is a front view of the helical pile core stiffness composite pile strength monitoring device based on the nail-driving theory proposed in this invention;

[0040] Figure 3 This is a cross-sectional view of the helical pile core stiffness composite pile strength monitoring device based on the nail-driving theory proposed in this invention;

[0041] Figure 4 This is a perspective view of the anchoring nail assembly of the helical pile core stiffness composite pile strength monitoring device based on the nail-shooting theory proposed in this invention.

[0042] Figure 5 This is a three-dimensional view of the soil isolation plate and the telescopic sleeve of the spiral pile core stiffness composite pile strength monitoring device based on the nail shooting theory proposed in this invention;

[0043] Figure 6 for Figure 3 Enlarged view of a portion of point A in the middle;

[0044] Figure 7 This is a perspective view of the linear drive component of the spiral pile core stiffness composite pile strength monitoring device based on the nail-shooting theory proposed in this invention.

[0045] The components are as follows: 1. Cylinder; 2. Telescopic sleeve; 2a. Guide sleeve; 3. Soil-separating plate assembly; 4. Cone head; 5. Linear drive assembly; 5a. Chain; 6. Sleeve storage tube; 7. Flange; 8. Guide hole; 9. Anchoring nail assembly; 10. First distance sensor; 11. Second distance sensor; 12. Transmission rod; 13. L-shaped clamp; 14. Soil-separating plate body; 15. Notch; 16. Clearance assembly; 161. Sliding plate; 162. U-shaped opening; 163. First magnetic block; 164. Second magnetic block. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Example 1:

[0048] like Figures 1-7 As shown, this embodiment of the invention provides a helical core stiffness composite pile strength monitoring device based on the nail-shooting theory. It is used to measure the physical properties of materials and is used to detect the strength of the cement-soil in the helical core stiffness composite pile. Specifically, it includes: a cylinder assembly, at least one set of telescopic sleeves 2, a soil isolation plate assembly 3, a telescopic power assembly, and an anchoring nail assembly 9.

[0049] like Figure 2As shown, the telescopic sleeve 2 is laterally arranged on the side of the insert assembly. Multiple telescopic sleeves 2 are distributed along the axial direction of the insert assembly, maintaining a consistent extension direction. A soil-isolating plate assembly 3 is installed at the end of the telescopic sleeve 2 furthest from the insert assembly. The soil-isolating plate assembly 3 is used to seal the end of the telescopic sleeve 2, allowing the soil outside the soil-isolating plate assembly 3 to be pushed to both sides during the extension of the telescopic sleeve 2. The channel area formed inside the telescopic sleeve 2 is used for the anchoring nail assembly 9 to fire nails. The telescopic power assembly is installed inside the insert assembly, using... The telescopic sleeve 2 is driven to extend and retract. The anchoring nail assembly 9 is installed inside the insert assembly and is used to fire nails in the direction of the telescopic sleeve 2. The measurement module is used to measure the depth of the nail driven into the helical core composite pile. That is, the measurement module feeds back the depth data of the nail driven into the helical core composite pile. This data is compared with the standard experimental data obtained in the laboratory (multiple composite pile samples with step-like strength are made in the laboratory and standard nail tests are performed on them to obtain the composite pile strength belonging to the data group with the nail driving depth) to evaluate the pile strength.

[0050] This invention, through the design of a sleeve assembly, mounts the anchoring nail assembly 9, the telescopic sleeve 2 (in the retracted state), the soil isolation plate assembly 3, the telescopic power assembly, and the anchoring nail assembly 9 all inside the sleeve assembly. This design protects the anchoring nail assembly 9, the telescopic sleeve 2 (in the retracted state), the soil isolation plate assembly 3, the telescopic power assembly, and the anchoring nail assembly 9 during the sleeve assembly setup. Before the nail firing test, the telescopic sleeve 2 is deployed, and the telescopic power assembly drives the telescopic sleeve 2 laterally towards the helical core-reinforced composite pile, forming a channel between the sleeve assembly and the helical core-reinforced composite pile for the anchoring nail assembly 9 to fire the nail for the experiment. The measurement module provides feedback on the depth of the nail driven into the helical core-reinforced composite pile, and this data is compared with standard experimental data obtained in the laboratory to evaluate the pile strength. Compared with low strain testing and borehole sampling methods, this experimental method has the advantages of simple operation and reliable experimental results.

[0051] It is worth noting that the testing process of the helical pile core stiffness composite pile strength monitoring device based on the nail shooting theory in this application is not limited by the cross-sectional shape of the pile, and can still be used in the strength testing process of piles with other complex cross-sections.

[0052] In one embodiment, the insert assembly includes: a cylinder 1, with a cone 4 fixedly installed at the bottom of the cylinder 1. The cone 4 at the bottom is used to guide the cylinder 1 downward into the soil layer, making the process of arranging the insert assembly easier. In some cases, depending on the depth of the helical core-reinforced composite pile, the cylinder 1 can be designed in a multi-section form, with telescopic sleeves 2 designed on some sections of the cylinder 1. The multi-section cylinder 1 is fixed by connecting the upper and lower sections together, such as by threaded connection, flange connection, etc.

[0053] In one embodiment, a sleeve storage tube 6 is fixedly connected to the inner side wall of the cylinder 1. The sleeve storage tube 6 is used to store the telescopic sleeve 2 in the retracted state. A circular opening is provided on the side wall of the cylinder 1 corresponding to the end of the sleeve storage tube 6. The shape of the circular opening is the boundary line between the sleeve storage tube 6 and the cylinder 1.

[0054] The telescopic sleeve 2 includes several axially slidingly connected guide sleeves, such as... Figure 3 As shown, the guide sleeve is designed in 5 sets. The guide sleeve at the first end of the telescopic sleeve 2 is slidably engaged with the inner side of the sleeve receiving tube 6. The soil isolation plate assembly 3 is installed at the end of the guide sleeve 2a at the second end of the telescopic sleeve 2. The remaining two adjacent guide sleeves are slidably engaged. Generally, an annular groove is provided on the inner wall of the end of the guide sleeve, and a matching protrusion is provided on the outer wall of the top of the guide sleeve. The protrusion and the groove cooperate to restrict radial displacement and allow axial expansion and contraction. When the axial expansion and contraction reaches the longest state, the protrusion is embedded in the groove to restrict the two from continuing to extend, thus preventing the two adjacent guide sleeves from separating.

[0055] The soil isolation plate assembly 3 is used to divert the outer soil layer during the deployment of the telescopic sleeve 2 to prevent soil from entering the interior of the telescopic sleeve 2. However, during the nailing process of the anchoring nail assembly 9, the soil isolation plate assembly 3 should not interfere with the nailing into the helical core rigid composite pile.

[0056] One approach is to design the soil barrier assembly 3 as a mesh metal frame and equip it with a fine mesh fabric, so that the nails launched by the anchor nail assembly 9 can easily pass through the mesh fabric and drive into the helical core rigid composite pile.

[0057] Another approach is to install a clearance component 16 that can be opened and closed on the soil barrier assembly 3.

[0058] Specifically, the clearance component 16 includes: a soil-separating plate 14, a sliding plate 161, a first magnetic block 163, and a second magnetic block 164.

[0059] A window is opened at the end of the soil-separating plate 14. The window can be rectangular. A U-shaped opening 162 is opened on one side of the sliding plate 161. The U-shaped opening 162 is slidably locked on the side of the window. A first magnetic block 163 is fixedly connected to the side of the window. A second magnetic block 164 is fixedly connected to the inside of the U-shaped opening 162. At least one of the first magnetic block 163 and the second magnetic block 164 is an electromagnet.

[0060] Adjusting the first magnetic block 163 and the second magnetic block 164 to a state where opposite poles attract each other allows the sliding plate 161 to slide to one side, opening the window on the soil-separating plate 14 for nail-shooting experiments; adjusting the first magnetic block 163 and the second magnetic block 164 to a state where like poles repel each other allows the sliding plate 161 to be pushed to the other side, completely closing the window on the soil-separating plate 14.

[0061] In one embodiment, two sets of sliding plates 161 may be symmetrically arranged, and each set of sliding plates 161 is equipped with a first magnetic block 163 and a second magnetic block 164.

[0062] In one embodiment, an L-shaped clip 13 is fixedly connected to the end of the guide sleeve 2a located at the second end of the telescopic sleeve 2, and a notch 15 is provided on the side of the soil isolation plate assembly 3.

[0063] In one embodiment, a flange 7 is fixedly connected to the end of the sleeve receiving tube 6. The flange 7 is used to install the anchoring nail assembly 9 and the measuring module.

[0064] The measurement module includes a first distance sensor 10 and a second distance sensor 11. Both the first distance sensor 10 and the second distance sensor 11 are fixedly connected to the flange 7. The first distance sensor 10 is used to detect the distance to the helical core-reinforced composite pile body, and the second distance sensor 11 is used to detect the distance to the end of the nail. The data from the first distance sensor 10 can be used independently to confirm whether the position of the insert assembly is appropriate. Furthermore, the combined data from the first distance sensor 10 and the second distance sensor 11 (the data from the first distance sensor 10 minus the data from the second distance sensor 11) can be used to obtain the depth data of the helical core-reinforced composite pile.

[0065] In some cases, the first distance sensor 10 and the second distance sensor 11 can be integrated into a multifunctional laser sensor.

[0066] Specifically, the telescopic power assembly includes: a linear drive assembly 5 and a transmission rod 12. The linear drive assembly 5 is fixedly connected to the inner wall of the cylinder 1. The telescopic end of the linear drive assembly 5 is fixedly connected to the transmission rod 12. A guide hole 8 is provided on the flange 7. The transmission rod 12 is slidably engaged with the guide hole 8. The end of the transmission rod 12 away from the linear drive assembly 5 is fixedly connected to the inner wall of the guide sleeve 2a located at the second end of the telescopic sleeve 2.

[0067] The linear drive assembly 5 drives the transmission rod 12 to move linearly. The guide hole 8 on the flange 7 guides the transmission rod 12. The transmission rod 12 pushes the guide sleeve 2a located at the second end of the telescopic sleeve 2 to move outward, causing the telescopic sleeve 2 to telescopically extend and retract outward.

[0068] In one embodiment, such as Figure 7 As shown, the linear drive assembly 5 is a flexible lifting assembly, the transmission rod 12 is a multi-section telescopic hollow sleeve, and one end of the chain 5a of the linear drive assembly 5 is fixedly connected to the inner end of the transmission rod 12. This structure design allows the linear drive assembly 5 with sufficient stroke to be installed in the limited space inside the cylinder 1. The hollow sleeve is used to protect the chain 5a of the linear drive assembly 5.

[0069] In one embodiment, the anchoring nail assembly 9 is an automatic nail gun with a nail storage compartment, which can automatically complete the nail firing action and the loading of nails, making it more convenient to use, especially since manual nail firing is inconvenient inside the cylinder 1.

[0070] Example 2:

[0071] The method for monitoring the strength of helical pile core-stiffness composite piles based on the nail-shooting theory, using the nail-shooting theory-based helical pile core-stiffness composite pile strength monitoring device in Example 1, specifically includes the following steps:

[0072] S1. Arrange the insert assembly:

[0073] Site clearance: Clear and level the construction site, place conspicuous construction notices, and ensure that there are no unauthorized personnel at the construction site.

[0074] Positioning: Use an adjustable laser locator to precisely locate the pile position. Select a point 10-30cm from the pile foundation location to ensure accuracy. The laser locator provides precise position guidance throughout the positioning process; the installation of the insert assembly requires using the located pile foundation location as a reference to determine the approximate range for subsequent device installation.

[0075] Then connect the insert assembly to the pile driver, and use the pile driver to drive the insert assembly into the predetermined depth at the selected point, while always keeping the telescopic sleeve 2 on the side of the insert assembly facing the helical core stiff composite pile.

[0076] S2, Expand telescopic sleeve 2:

[0077] The telescopic power component is used to push the telescopic sleeve 2 to move outward, and the soil in the area where the soil isolation plate component 3 passes is pushed to both sides until the soil isolation plate component 3 is in close contact with the outer side of the spiral core rigid composite pile.

[0078] S3. Nail firing and calculation:

[0079] The anchoring nail assembly 9 is activated, and the nail is fired into the helical core-reinforced composite pile along the direction of the telescopic sleeve 2. The depth of the nail driven into the helical core-reinforced composite pile is measured based on the measurement module.

[0080] The pile strength is evaluated by comparing the depth data of the driven helical core-reinforced composite pile with standard experimental data obtained in the laboratory.

[0081] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A strength monitoring device for helical pile core stiffness composite piles based on nail-driving theory, characterized in that, include: Insert assembly; At least one set of telescopic sleeves (2) are provided on the side of the insert assembly, and a soil-separating plate assembly (3) is installed at the end of the telescopic sleeve (2) away from the insert assembly; Telescopic power assembly, which is installed inside the insert assembly and is used to drive the telescopic sleeve (2) to telescopically extend and retract. Anchoring nail assembly (9), which is installed inside the insert assembly for firing nails toward the telescopic sleeve (2); A measurement module is used to measure the depth to which a nail is driven into a spiral core-reinforced composite pile.

2. The strength monitoring device for helical pile core stiffness composite pile based on nail-driving theory according to claim 1, characterized in that, The insert assembly includes: A cylindrical body (1) with a cone head (4) fixedly installed at the bottom.

3. The strength monitoring device for helical pile core stiffness composite pile based on nail-driving theory according to claim 2, characterized in that: The inner wall of the cylinder (1) is fixedly connected to a sleeve receiving tube (6), and a round opening is provided on the side wall of the cylinder (1) corresponding to the end of the sleeve receiving tube (6). The telescopic sleeve (2) includes several axially slidingly connected guide sleeves. The guide sleeve located at the first end of the telescopic sleeve (2) is slidably engaged with the inner side of the sleeve receiving tube (6). The soil isolation plate assembly (3) is installed at the end of the guide sleeve (2a) located at the second end of the telescopic sleeve (2). The soil barrier assembly (3) is provided with a clearance assembly (16).

4. The strength monitoring device for helical pile core stiffness composite pile based on nail-driving theory according to claim 3, characterized in that: An L-shaped clamp (13) is fixedly connected to the end of the guide sleeve (2a) located at the second end of the telescopic sleeve (2), and a notch (15) is provided on the side of the soil isolation plate assembly (3).

5. The strength monitoring device for helical pile core stiffness composite pile based on nail-driving theory according to claim 3, characterized in that, The yielding component (16) includes: A soil barrier plate (14), with a window at one end of the soil barrier plate (14); A sliding plate (161) has a U-shaped opening (162) on one side. The U-shaped opening (162) is slidably locked on the side of the window, and a first magnetic block (163) is fixedly connected to the side of the window. A second magnetic block (164) is fixedly connected to the inside of the U-shaped opening (162). At least one of the first magnetic block (163) and the second magnetic block (164) is an electromagnet.

6. The strength monitoring device for helical pile core stiffness composite pile based on nail-driving theory according to claim 3, characterized in that: The end of the sleeve receiving tube (6) is fixedly connected to a flange (7); The telescopic power assembly includes: a linear drive assembly (5) and a transmission rod (12). The linear drive assembly (5) is fixedly connected to the inner wall of the cylinder (1). The telescopic end of the linear drive assembly (5) is fixedly connected to the transmission rod (12). A guide hole (8) is provided on the flange (7). The transmission rod (12) is slidably engaged with the guide hole (8). The end of the transmission rod (12) away from the linear drive assembly (5) is fixedly connected to the inner wall of the guide sleeve (2a) located at the second end of the telescopic sleeve (2).

7. The strength monitoring device for helical pile core stiffness composite pile based on nail-driving theory according to claim 6, characterized in that, The measurement module includes a first distance sensor (10) and a second distance sensor (11). Both the first distance sensor (10) and the second distance sensor (11) are fixedly connected to the flange (7). The first distance sensor (10) is used to detect the distance to the helical core stiff composite pile body, and the second distance sensor (11) is used to detect the distance to the end of the nail.

8. The strength monitoring device for helical pile core stiffness composite pile based on nail-driving theory according to claim 6, characterized in that: The linear drive assembly (5) is a flexible lifting assembly, and the transmission rod (12) is a multi-section telescopic hollow sleeve. One end of the chain (5a) of the linear drive assembly (5) is fixedly connected to the inner end of the transmission rod (12).

9. The strength monitoring device for helical pile core stiffness composite pile based on nail-driving theory according to claim 1, characterized in that: The anchoring nail assembly (9) is an automatic nail gun with a nail storage compartment.

10. A method for monitoring the strength of helical pile core-strength composite piles based on nail-driving theory, characterized in that, The strength monitoring device for helical pile core stiffness composite piles based on the nail-driving theory as described in any one of claims 1-9 specifically includes the following steps: S1. Arrange the insert assembly: Select a point 10-30cm outside the spiral core rigid composite pile, then connect the insert assembly to the pile driver, and use the pile driver to drive the insert assembly into the selected point to a predetermined depth, and always keep the telescopic sleeve (2) on the side of the insert assembly facing the spiral core rigid composite pile. S2, unfold the telescopic sleeve (2): Using the telescopic power assembly to push the telescopic sleeve (2) to move outward, the soil in the area where the soil isolation plate assembly (3) passes is pushed to both sides until the soil isolation plate assembly (3) is pressed against the outside of the spiral core rigid composite pile. S3. Nail firing and calculation: Start the anchoring nail assembly (9), fire the nails into the helical core-reinforced composite pile along the direction of the telescopic sleeve (2), and measure the depth of the nails driven into the helical core-reinforced composite pile based on the measurement module; The pile strength is evaluated by comparing the depth data of the driven helical core-reinforced composite pile with standard experimental data obtained in the laboratory.

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