Working method of tower foundation structure for preventing and controlling freeze-thaw deformation in seasonal frozen soil region

Abstract

The invention discloses a working method of a tower foundation structure for preventing and controlling freeze-thaw deformation in a seasonal frozen soil region. In the tower foundation structure, the lower portion of a pile body is connected with the top of a center cylinder through a hydraulic damper, the outer side of the bottom of the center cylinder is sleeved with an isolation cylinder, a conical cylinder is fixedly connected to the top of the isolation cylinder, and the conical cylinder is slidably connected to the outer side of the top of the center cylinder; the periphery of the central cylinder is fixedly connected with an upper inclined strut which is inclined upwards and a lower inclined strut which is inclined downwards; the end parts of the upper inclined strut and the lower inclined strut are movably inserted into through holes in the side wall of the isolation cylinder respectively; the bottom of the isolation cylinder is fixedly connected with a base, a lock pin is fixed to the upper portion of the base, the bottom of the center cylinder is hollow to form a center cylinder cavity allowing the lock pin to be inserted, the lock pin is slidably connected with the bottom of the center cylinder through the center cylinder cavity, a gap is reserved between the bottom of the center cylinder and the base, the hydraulic damper forms first-level prevention and control, and the upper inclined strut and the lower inclined strut form second-level prevention and control. The conical barrels form three-stage prevention and control, and the three stages of prevention and control work together to achieve whole-process control over frost heaving and thaw collapse deformation.

Description

[0001] This invention application is a divisional application of the parent application "A tower foundation structure and construction method for preventing and controlling freeze-thaw deformation in seasonal frozen soil areas". The application number of the parent application is 2025109128827, and the application date is July 3, 2025. Technical Field

[0002] The present invention relates to the technical field of construction for preventing and controlling freeze-thaw deformation of power transmission and transformation facility foundations, and in particular to a pole tower foundation structure and a construction method for preventing and controlling freeze-thaw deformation in seasonally frozen soil areas. Background Art

[0003] my country's seasonally frozen ground areas are widely distributed across Northeast China, North China, Northwest China, and the edge of the Qinghai-Tibet Plateau. These areas are characterized by significant interannual freeze-thaw cycles, characterized by soil expansion during winter and thawing and settling during summer. In recent years, the scale of power transmission and transformation projects in these areas has continued to expand. However, frequent freeze-thaw cycles in these areas cause repeated freeze-heaving and thawing settlement of the soil surrounding tower foundations, leading to foundation uplift, tilting, and even fracture, posing a serious threat to the safe operation of the power grid.

[0004] Traditional tower foundations often utilize shallow buried designs. While this offers the advantages of convenient construction and low cost, it is directly exposed to the active freeze-thaw layer, making it susceptible to frost heave forces generated by soil phase transitions. Current prevention and control technologies focus primarily on two categories: one is to suppress deformation by enhancing the frost resistance of foundation materials (e.g., high-strength concrete, fiber-reinforced composites), but this material cost is high and the effects of frost heave forces cannot be eliminated. The other is to employ deep foundations or thermal insulation measures (e.g., polystyrene insulation layers, gravel replacement). While these measures can partially mitigate frost damage, they significantly increase construction complexity and cost, and are not adaptable enough in areas with severe frost heave. The current technical bottleneck lies in the excessive pursuit of a "zero-deformation" rigid resistance model for the foundation, while neglecting to optimize the soil-foundation interaction mechanism during freeze-thaw cycles. Traditional structures lack a design to dissipate the repeated stresses caused by freeze-thaw cycles, which can easily lead to foundation fatigue damage. Therefore, a new foundation structure that balances cost-effectiveness and reliability is urgently needed. This new foundation structure can achieve active prevention and control of freeze-thaw deformation by reshaping the frost heave force distribution and improving the coordinated deformation capacity of the foundation and frozen soil.

[0005] Based on the concept of "combination of guidance and dredging", this invention breaks through the rigid anti-freeze thinking and proposes a tower foundation that integrates a load-sharing structure. It comprehensively solves the freeze-thaw deformation problem from three dimensions: optimization of the frost heave force transmission path, release of deformation energy and automatic locking, and provides an innovative solution for the long-term and stable operation of power infrastructure in seasonally frozen areas. Summary of the Invention

[0006] The purpose of the present application is to provide a tower foundation structure for preventing and controlling freeze-thaw deformation in seasonal frozen soil areas to address the technical defects in the prior art.

[0007] Another purpose of the present application is to provide a construction method of the tower foundation structure.

[0008] The technical scheme adopted to achieve the purpose of the present application is as follows:

[0009] A tower foundation structure for preventing and controlling freeze-thaw deformation in seasonal frozen soil areas, comprising a pile body, a hydraulic damper, a conical cylinder, an isolation cylinder, and a central cylinder, wherein:

[0010] The lower part of the pile body is connected to the top of the central cylinder through the hydraulic damper, the bottom outer side of the central cylinder is sleeved with the isolation cylinder, the conical cylinder is fixedly connected to the top of the isolation cylinder, and the conical cylinder is slidingly connected to the outer side of the top of the central cylinder.

[0011] The central cylinder is fixedly connected with an upwardly inclined upper inclined strut and a downwardly inclined lower inclined strut, the ends of the upper inclined strut and the lower inclined strut are respectively movably inserted into the through holes in the side wall of the isolation cylinder, and the upper inclined strut and the lower inclined strut are made of elastic material.

[0012] The bottom of the isolation cylinder is fixedly connected with a base, the upper part of the base is fixedly connected with a locking pin, the bottom of the central cylinder is hollow to form a central cylinder cavity for inserting the locking pin, the locking pin is slidingly connected to the bottom of the central cylinder through the central cylinder cavity, and a gap is left between the bottom of the central cylinder and the base.

[0013] The isolation cylinder is completely located below the seasonal frozen soil layer, the pile body, the conical cylinder, and the hydraulic damper are completely located within the seasonal frozen soil layer, the top of the pile body is flush with the natural ground surface, and the bottom of the conical cylinder is flush with the maximum seasonal frozen depth.

[0014] Another aspect of the present application also includes a working method of the tower foundation structure, comprising the following steps:

[0015] When the season frozen soil freezes and expands, the tangential frost heaving force is generated and acts on the pile body preferentially, driving the pile body to produce upward displacement, the hydraulic damper is first in action, the hydraulic damper provides resistance in the opposite direction of the frost heaving force, offsetting the influence of the frost heaving force, when the hydraulic damper reaches the locking state, the pile body drives the center cylinder to move upward, the upper inclined support starts to act, the upper inclined support gradually extends from the through hole of the isolation cylinder and penetrates into the surrounding soil, forming a "barb" anchoring effect; at the same time, the lower inclined support is retracted into the isolation cylinder; when entering the warm season thawing subsidence stage, the soil melting causes the pile body to be subjected to downward pulling, so that the hydraulic damper returns to the initial position, with the further development of thawing subsidence, the center cylinder starts to move downward under the driving of the pile body, at this time, the lower inclined support extends from the through hole and penetrates into the surrounding soil, and the side wall friction resistance is increased to inhibit the structure settlement, when the bottom of the center cylinder contacts the base, the base will provide the final bearing capacity support.

[0016] In the above technical solution, the material of the upper inclined support and the lower inclined support is a metal with elasticity.

[0017] In the above technical solution, the inclination angle of the conical cylinder is not less than 26.57°.

[0018] In the above technical solution, the upper inclined support and the lower inclined support are fixed alternately in layers on the outside of the center cylinder, each layer of upper inclined support is composed of N upper support pieces inclined upward at the same height, and each layer of lower inclined support is composed of N lower support pieces inclined downward at the same height.

[0019] In the above technical solution, N is 3-6.

[0020] In the above technical solution, the N upper support pieces at the same height are evenly distributed in the form of umbrella on the outside of the center cylinder, and the N lower support pieces at the same height are evenly distributed in the form of umbrella on the outside of the center cylinder.

[0021] In the above technical solution, the hydraulic damper comprises a piston body fixed to the bottom of the pile body, a hydraulic cavity formed at the top of the center cylinder, and a plurality of damping channels formed in the side wall of the top of the center cylinder, the piston body is slidably connected in the hydraulic cavity, the hydraulic cavity is divided into an upper hydraulic cavity and a lower hydraulic cavity, the upper hydraulic cavity and the lower hydraulic cavity are filled with anti-freezing medium, a sealing ring is fixed on the outer wall of the piston body, the two ends of each damping channel are open and connected with the hydraulic cavity, and the one ends of the plurality of damping channels are arranged from high to low.

[0022] In the above technical solution, the center lines of the plurality of damping channels are located on the same straight line.

[0023] In the above technical solution, each damping channel is in arc structure.

[0024] In the technical scheme, the cross-sectional area of the upper hydraulic cavity minus the cross-sectional area of the piston body is equal to the cross-sectional area of the lower hydraulic cavity.

[0025] Another aspect of the application also includes a construction method of the tower foundation structure, comprising the following steps:

[0026] S1, construction preparation: conduct permafrost geological survey, understand the seasonal permafrost characteristics of the site, and develop a construction plan according to the same;

[0027] S2, foundation positioning: use measuring instruments to perform site setting-out, determine the center position and elevation control point of the foundation, and mark the installation position of each structural component;

[0028] S3, structure manufacturing and assembly: prefabricate main components in a factory, assemble the hydraulic damper on site and test the sealing performance, weld and fix the upper inclined brace, the lower inclined brace and the center cylinder, complete the overall pre-assembly and check the fitting size of each component;

[0029] S4, drilling: use a rotary drilling rig to perform pile hole construction, the drilling diameter needs to be greater than the design isolation cylinder diameter, strictly control the verticality deviation during drilling, timely handle the hole wall collapse, remove the hole bottom sediment after hole forming, and ensure the hole bottom flatness;

[0030] S5, structure hoisting: use a special lifting appliance for overall hoisting, strictly control the accuracy of the structure in place, timely install temporary supports after the structure is in place, and ensure construction safety;

[0031] S6, pore backfilling and compaction: backfill improved soil in layers, use small compaction equipment to compact layer by layer, pause when backfilling to the bottom of the conical cylinder, and continue backfilling to the design elevation after checking the verticality of the structure;

[0032] S7, engineering acceptance: comprehensively detect the installation quality of the structure, complete the construction acceptance record, and complete the corrosion protection treatment.

[0033] Compared with the prior art, the application has the following beneficial effects:

[0034] 1. The system has multi-level control, which is the first level control of the hydraulic damper, the second level control of the upper inclined brace and the lower inclined brace, and the third level control of the conical cylinder, which changes the direction of the frost heaving force and converts the destructive normal force into beneficial constraint force, and the first, second and third level controls work together to realize the whole process control of the frost heaving and thawing settlement deformation.

[0035] 2. The conical cylinder, the base and the locking pin work together to allow the center cylinder to move only in a strictly vertical direction, completely avoiding the possibility of lateral inclination, and significantly improving the safety and reliability of the tower foundation under complex permafrost conditions.

[0036] 3. The hydraulic damper's progressive pressurization achieves three key functions: first, it significantly reduces peak frost-uplift forces through hydraulic reaction; second, it effectively dissipates axial tensile stress in the pile foundation; and finally, it prevents excessive pile uplift while allowing controlled displacement. This dynamic balancing mechanism not only protects the structural integrity of the pile but also significantly improves the foundation's stability during repeated freeze-thaw cycles of seasonally frozen soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Shown is a schematic diagram of the overall structure of the present invention.

[0038] Figure 2 It is a schematic diagram of the connection structure of the pile body, hydraulic damper, central tube, upper diagonal brace and lower diagonal brace.

[0039] Figure 3 It is a structural diagram of the tapered cylinder, base and locking pin.

[0040] Figure 4 It is a structural diagram of the isolation cylinder.

[0041] Figure 5 It is a cross-sectional view of the present invention.

[0042] Figure 6 is a cross-sectional view of a hydraulic damper.

[0043] Figure 7 It is a schematic diagram of the frost heave force acting on the inclined surface of the cone.

[0044] Figure 8 It is a flow chart of the construction method of the present invention.

[0045] In the figure: 1. Pile body; 2. Hydraulic damper; 3. Conical cylinder; 4. Isolation cylinder; 5. Base; 6. Damping channel; 7. Upper diagonal brace; 8. Lower diagonal brace; 9. Center cylinder; 10. Center cylinder cavity; 11. Lock pin; 12. Isolation cavity; 13. Upper hydraulic cavity; 14. Lower hydraulic cavity; 15. Piston body; 16. Sealing ring; 17. Through hole. DETAILED DESCRIPTION

[0046] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0047] Example 1

[0048] like Figures 1-5 As shown, a tower foundation structure for preventing and controlling freeze-thaw deformation in seasonally frozen soil areas includes a pile body 1, a hydraulic damper 2, a tapered tube 3, an isolation tube 4, and a central tube 9, wherein:

[0049] The lower part of the pile body 1 is connected with the top of the central cylinder 9 through the hydraulic damper 2, the outside of the bottom of the central cylinder 9 is sleeved with the isolation cylinder 4, the conical cylinder 3 is fixedly connected with the top of the isolation cylinder 4, and the conical cylinder 3 is slidably connected with the outside of the top of the central cylinder 9;

[0050] The upper inclined braces 7 and the lower inclined braces 8 are fixedly connected around the central cylinder 9 and are inclined upwards and downwards respectively, and the ends of the upper inclined braces 7 and the lower inclined braces 8 are movably inserted into the through holes 17 in the side wall of the isolation cylinder 4 respectively;

[0051] The bottom of the isolation cylinder 4 is fixedly connected with the base 5, the upper part of the base 5 is fixedly connected with the locking pin 11, the bottom of the central cylinder 9 is hollow to form the central cylinder cavity 10 for inserting the locking pin 11, the locking pin 11 is slidably connected with the bottom of the central cylinder 9 through the central cylinder cavity 10, and a gap is left between the bottom of the central cylinder 9 and the base 5;

[0052] The isolation cylinder 4 is completely located below the seasonally frozen soil layer, the pile body 1, the conical cylinder 3 and the hydraulic damper 2 are completely located in the seasonally frozen soil layer, the top of the pile body 1 is flush with the natural ground surface, and the bottom of the conical cylinder 3 is flush with the maximum seasonal frozen depth.

[0053] When the seasonally frozen soil freezes and expands, the tangential frost heaving force generated acts on the pile body 1 preferentially, drives the pile body 1 to generate upward displacement, the hydraulic damper 2 acts first, the hydraulic damper 2 provides resistance in the opposite direction of the frost heaving force, offsets the influence of the frost heaving force, when the hydraulic damper 2 reaches the locking state, the pile body 1 drives the central cylinder 9 to move upwards, and the upper inclined braces 7 begin to act, specifically, the upper inclined braces 7 gradually extend out of the through holes 17 of the isolation cylinder 4 and pierce into the surrounding soil, form an anchoring effect similar to "barbs", and in the development process of the frost heaving, with the upper inclined braces 7 gradually extending out and anchoring into the surrounding soil, the force applied to the isolation cylinder 4 by the upper inclined braces 7 is synchronously enhanced; at the same time, the lower inclined braces 8 are retracted into the isolation cylinder 4. The upper inclined braces 7 and the lower inclined braces 8 are made of metal with elasticity, and always remain in an elastic deformation state in the whole movement process, so as to ensure the reusable performance. In the warm season thawing and subsidence stage, the system presents self-adaptive recovery characteristics: firstly, the soil melts, the pile body 1 is pulled downward, and the hydraulic damper 2 returns to the initial position; with the further development of the thawing and subsidence, the central cylinder 9 begins to move downward under the driving of the pile body 1, at this time, the lower inclined braces 8 extend out of the through holes 17 and pierce into the surrounding soil, and inhibit the structure settlement by increasing the side wall friction resistance. When the bottom of the central cylinder 9 is in contact with the base 5, the base 5 will provide the final bearing capacity support. It is particularly worth noting that the elastic restoring force of the upper inclined braces 7 and the lower inclined braces 8 will act synergistically to push the central cylinder 9 to accurately return to the initial design position, and this characteristic effectively guarantees the dimensional stability and durability of the structure in the multi-year freezing and thawing cycle. In the whole working process, the upper inclined braces 7, the lower inclined braces 8 and the hydraulic damper form perfect cooperation, and realize the whole process control of the frost heaving and thawing and subsidence deformation.

[0054] The mechanical optimization design of the cone 3 achieves a self-locking effect of frost heave force. When the freezing front extends to the buried depth of the cone 3, its unique inclined structure plays a key role: by changing the direction of the frost heave force, the original destructive normal force is converted into a beneficial restraining force. Specifically, Figure 7 As shown in the figure, the frost heave force on the inclined surface of the cone is decomposed into the normal force (F f ) and tangential force (F q ), the vertical component F fs 、F qs There is a clear mechanical relationship. By accurately calculating the inclination angle of the tapered tube, ensure that F qs ≤F fs The mechanical conditions always hold.

[0055] F f ×sinθ≥F q ×cosθ

[0056] Where: F f F is the normal component of the frost heave force on the inclined surface of the cone; q is the tangential component of the frost heave force on the tapered tube slope; θ is the angle between the tapered tube slope and the vertical. The inclination angle θ of the tapered tube 3 should be no less than 26.57°. This design cleverly utilizes the frost heave force itself to automatically lock the tapered tube 3, effectively suppressing the upward displacement of the isolation tube 4. This provides a reliable bottom anchoring force for the pile 1 and significantly improves the foundation's stability during the frost heave period.

[0057] The structure's anti-overturning stability is ensured by a triple guarantee mechanism consisting of the conical tube 3, the base 5, and the locking pin 11. The spatial constraint principle of the three components is as follows: the central tube 9 is precisely restricted to movement within the internal space of the conical tube 3, while the top of the locking pin 11 penetrates the central tube cavity 10, and the bottom of the locking pin 11 is rigidly connected to the base 5. This nested structural design forms a three-dimensional constraint system, whose mechanical characteristics are as follows: first, the precise fit between the inner wall of the conical tube 3 and the outer wall of the central tube 9 limits horizontal displacement; second, the guiding effect of the locking pin 11 within the central tube cavity 10 ensures the linearity of vertical movement; finally, the fixed connection between the base 5 and the isolation tube 4 provides a stable foundation platform.

[0058] Preferably, the upper and lower diagonal braces 7 and 8 are alternately fixed in layers on the exterior of the central tube 9. Each layer of upper diagonal braces 7 is composed of N upper support pieces at the same height, tilted upward, and each layer of lower diagonal braces 8 is composed of N lower support pieces at the same height, tilted downward. More preferably, N is 3 to 6. The N upper support pieces at the same height are evenly distributed on the exterior of the central tube 9 in an umbrella-like pattern, while the N lower support pieces at the same height are evenly distributed on the exterior of the central tube 9 in an umbrella-like pattern.

[0059] Example 2

[0060] like Figure 6 As shown, this embodiment further optimizes the structure of the hydraulic damper 2 based on the embodiment 1.

[0061] The hydraulic damper 2 includes a piston body 15 fixed to the bottom of the pile body 1, a hydraulic chamber formed at the top of the center tube 9, and multiple damping channels 6 formed on the side wall of the top of the center tube 9. The piston body 15 is slidably connected to the hydraulic chamber. The hydraulic chamber includes an upper hydraulic chamber 13 and a lower hydraulic chamber 14. The upper hydraulic chamber 13 and the lower hydraulic chamber 14 are filled with antifreeze medium. A sealing ring 16 is fixed on the outer wall of the piston body 15. The openings at both ends of each damping channel 6 are connected to the hydraulic chamber. The openings at one end of multiple damping channels 6 are arranged from high to low. Preferably, the center lines of multiple damping channels 6 are located on the same straight line.

[0062] The cross-sectional area of ​​the upper hydraulic chamber 13 minus the cross-sectional area of ​​the piston body 15 equals the cross-sectional area of ​​the lower hydraulic chamber 14. This ensures that when the piston body 15 moves, the volume changes of the upper hydraulic chamber 13 and the lower hydraulic chamber 14 are equal, ensuring the normal movement of the piston body 15.

[0063] When the tangential frost heave force acts on the pile body 1 , the pile body 1 drives the piston body 15 to slide upward in the hydraulic damper 2 , compressing the antifreeze medium in the upper hydraulic chamber 13 . The antifreeze medium in the upper hydraulic chamber 13 enters the damping channel 6 through one end opening of the damping channel 6 and flows out from the other end opening into the lower hydraulic chamber 14. In this embodiment, three damping channels 6 are provided. More preferably, each damping channel 6 is an arc-shaped structure. In the initial stage of freeze drawing, the center line of the piston body 15 is located on the center line of the damping channel 6. One end opening of each damping channel 6 is located in the upper hydraulic chamber 13, and the other end opening is located in the lower hydraulic chamber 14. Antifreeze medium flows in the three damping channels 6. As freeze drawing further occurs, the piston body 15 rises, and the number of damping channels 6 with openings located on the upper part of the piston body 15 decreases, that is, the number of damping channels 6 for the circulation of antifreeze medium decreases, first reducing to two damping channels 6 for the circulation of antifreeze medium, and then reducing to one. In this process, the resistance gradually increases, and the pressure of the antifreeze medium in the upper hydraulic chamber 13 acting on the piston body 15 gradually increases.

[0064] During the entire freeze-pulling process, thanks to the incompressible characteristics of the antifreeze medium and the damping effect of the damping channel 6, a progressive pressurization process is formed in the upper hydraulic chamber 13. This pressure reacts to the pile body 1 through the piston body 15, generating an anchoring force in the opposite direction of the frost heave force, thereby effectively decomposing and offsetting the impact of the frost heave force. During the continuous action of the frost heave force, the system exhibits intelligent response characteristics: as the pile body 1 slowly rises, the sealing ring 16 moves synchronously with the piston body 15, gradually closing the damping channel 6 in a preset order. This progressive closing mechanism ensures that the system's damping force increases with increasing displacement. When all damping channels 6 are completely closed, the system reaches a force balance state and the piston body 15 stops moving.

[0065] In the initial stage of frost heave, when all the damping channels 6 of the hydraulic damper 2 are completely closed and the piston body 15 reaches a locked state, as the frost heave force continues to act, the pile body 1 will drive the central tube 9 to move upward as a whole.

[0066] Example 3

[0067] like Figure 7 As shown, the construction method of the tower foundation structure for preventing and controlling freeze-thaw deformation in seasonal frozen soil areas includes the following steps:

[0068] S1. Construction Preparation: Before construction, a detailed geological survey of seasonal frozen ground is required to understand the characteristics of the site's seasonal frozen ground. Based on the survey results, a special construction plan is developed, necessary construction equipment and materials are prepared, and technical instructions are provided to the construction personnel.

[0069] S2, Foundation Positioning: Use surveying instruments to lay out the site and determine the foundation center and elevation control points. Mark the installation locations of each structural component to ensure accurate positioning.

[0070] S3, structural fabrication and assembly: prefabricate the main components in the factory and assemble on site. The assembly process is to first assemble the hydraulic damper 2, then weld the upper diagonal brace 7 and the lower diagonal brace 8 to the outside of the central tube 9, assemble the isolation tube 4, and then weld the isolation tube 4 to the base 5, and finally weld the tapered tube 3 to complete the overall pre-assembly and check the matching dimensions of each component.

[0071] S4, Drilling: Use a rotary drilling rig to construct the pile hole. The drill hole diameter should be slightly larger than the designed isolation tube diameter. Strictly control vertical deviation during drilling and promptly address any problems such as hole wall collapse. After drilling, remove any sediment from the bottom of the hole to ensure a smooth, level hole bottom.

[0072] S5, Structure Hoisting: Use special hoisting equipment for overall hoisting, strictly control the positioning accuracy. After the structure is in place, install temporary supports in a timely manner to ensure construction safety.

[0073] S6, hole backfilling and compaction: stratified backfilling of improved soil material, and layer by layer compaction with small compaction equipment. Stop when backfilling to the bottom of the conical cylinder, and continue backfilling to the design elevation after checking the vertical condition of the structure.

[0074] S7, project acceptance: comprehensive detection of the installation quality of the structure, including geometric size, mechanical property, etc. Complete the construction acceptance record, and complete the finishing work such as corrosion protection.

[0075] The above is only the preferred embodiment of the present application, it should be noted that for those skilled in the art, without departing from the principles of the present application, can make a number of improvements and refinements, these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A working method for a tower foundation structure for preventing and controlling freeze-thaw deformation in seasonally frozen soil areas, characterized in that: The tower foundation structure includes a pile body, a hydraulic damper, a tapered tube, an isolation tube and a central tube, wherein: The lower part of the pile body is connected to the top of the central tube through a hydraulic damper. An isolation tube is sleeved on the outer side of the bottom of the central tube. The conical tube is fixedly connected to the top of the isolation tube, and the conical tube is slidably connected to the outer side of the top of the central tube. An upper diagonal brace inclined upward and a lower diagonal brace inclined downward are fixedly connected around the central tube. The ends of the upper diagonal brace and the lower diagonal brace are movably inserted into the through holes on the side wall of the isolation tube. The upper diagonal brace and the lower diagonal brace are made of elastic material. The bottom of the isolation tube is fixedly connected to the base, a locking pin is fixed to the upper part of the base, the bottom of the central tube is hollow to form a central tube cavity for the locking pin to be inserted, the locking pin is slidably connected to the bottom of the central tube through the central tube cavity, and a gap is left between the bottom of the central tube and the base; The isolation cylinder is completely located below the seasonal frozen soil layer, and the pile body, conical cylinder, and hydraulic damper are completely located within the seasonal frozen soil layer. The top of the pile body is flush with the natural ground surface, and the bottom of the conical cylinder is flush with the maximum seasonal freezing depth. The working method comprises the following steps: When seasonal frozen soil expands, the resulting tangential frost-heave force preferentially acts on the pile, driving it upward. The hydraulic damper activates first, providing resistance in the opposite direction of the frost-heave force, offsetting its influence. When the hydraulic damper reaches the locked state, the pile drives the central tube upward, and the upper diagonal brace begins to take effect. The upper diagonal brace gradually extends from the through-hole of the isolation tube and penetrates the surrounding frozen soil, forming a "barb" anchoring effect. At the same time, the lower diagonal brace retracts into the isolation tube. During the warm-season thaw settlement phase, the thawing soil pulls the pile downward, causing the hydraulic damper to return to its initial position. As thaw settlement continues, the central tube begins to move downward, driven by the pile. At this time, the lower diagonal brace extends from the through-hole and penetrates the surrounding soil, suppressing structural settlement by increasing sidewall friction resistance. When the bottom of the central tube contacts the base, the base provides the final bearing capacity support.

2. The working method according to claim 1, characterized in that The upper diagonal brace and the lower diagonal brace are made of elastic metal.

3. The working method according to claim 1, characterized in that: The inclination angle of the tapered tube slope is not less than 26.57°.

4. The working method according to claim 1, characterized in that: The upper and lower diagonal braces are alternately fixed on the outside of the central tube in layers, and each layer of upper diagonal braces is composed of N upper support pieces inclined upward at the same height, and each layer of lower diagonal braces is composed of N lower support pieces inclined downward at the same height.

5. The working method according to claim 4, characterized in that: N is 3 to 6.

6. The working method according to claim 4, characterized in that: N upper supporting pieces at the same height are evenly distributed outside the central tube in an umbrella shape, and N lower supporting pieces at the same height are evenly distributed outside the central tube in an umbrella shape.

7. The working method according to claim 1, characterized in that: The hydraulic damper includes a piston body fixed to the bottom of the pile body, a hydraulic chamber formed at the top of the center tube, and multiple damping channels formed on the side wall of the top of the center tube. The piston body is slidably connected to the hydraulic chamber. The hydraulic chamber is divided into an upper hydraulic chamber and a lower hydraulic chamber. The upper hydraulic chamber and the lower hydraulic chamber are filled with antifreeze medium. A sealing ring is fixed on the outer wall of the piston body. The openings at both ends of each damping channel are connected to the hydraulic chamber, and the openings at one end of multiple damping channels are arranged from high to low.

8. The working method according to claim 1, characterized in that: The center lines of the multiple damping channels are located on the same straight line, and each damping channel is an arc-shaped structure.

9. The working method according to claim 7, characterized in that: The cross-sectional area of ​​the upper hydraulic chamber minus the cross-sectional area of ​​the piston body is equal to the cross-sectional area of ​​the lower hydraulic chamber.

Images