Ice bolt pile in permafrost region and construction method

Abstract

The invention provides a permafrost region ice bolt pile and a construction method, the permafrost region ice bolt pile is suitable for road and railway roadbed engineering, and the ice bolt pile is jointly composed of a pile body center shaft, a connector, a bionic conical tooth structure, small-diameter threaded blades, reserved connecting holes and a splicing reinforcing assembly; the two sets of pile body center shafts are arranged and are each of a hollow structure, bionic conical teeth are integrated at the bottom ends of the pile body center shafts of the lower side set, and small-diameter threaded blades are further arranged on the peripheral walls of the pile body center shafts. The construction method comprises the following key procedures: (a) geological exploration analysis; (b) prefabricating a pile body assembly; (c) field pretreatment; (d) measuring and positioning; (e) pile position calibration; (f) screwing in an ice bolt pile; (g) splicing the pile sections step by step; (h) removing residual frozen soil chippings in the hollow shaft; (i) specially-made reinforcing slurry is poured in a layered mode. The bearing capacity and stability of the pile foundation in the permafrost region can be improved, and the safety and stability of roadbed engineering are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of highway and railway roadbed construction, and in particular to an ice bolt pile in permafrost areas and a construction method thereof. Background Art

[0002] In the context of the global shift toward a green, low-carbon development paradigm, traditional piles are unable to meet the requirements of sustainable development in engineering construction due to their high carbon emissions, complex construction procedures, and limited bearing capacity. Furthermore, given the unique geological environment of permafrost regions, foundation construction in permafrost areas faces three technical challenges: thermal disturbances triggering permafrost thawing and settlement; mechanical extrusion destabilizes permafrost structures; and long-term freeze-thaw cycles under a "warming and humid" climate lead to changes in pile performance and degradation of the mechanical properties of the soil interface. Existing engineering technology systems have significant deficiencies in permafrost stability control, making them unable to meet the reliability design requirements for cold-region roadbeds and posing a persistent threat to road foundation safety. To address this, the present invention proposes an ice bolt pile structure and construction method. By integrating permafrost thermal disturbance suppression technology, a freeze-thaw cycle adaptive adjustment mechanism, and a spiral blade-enhanced anchoring system, this structure achieves a synergistic optimization of high-efficiency compressive performance during the pile screw-in phase and enhanced pullout performance during the refreezing phase through mechanical engagement. This technology will effectively improve the long-term stability and service durability of roadbed projects in permafrost regions, providing key technical support for roadbed construction in permafrost areas. Summary of the Invention

[0003] In order to solve the problems in the background technology, the present invention provides an ice bolt pile and construction method in permafrost areas, aiming to solve the problems of large thermal disturbance, large impact of freeze-thaw cycles, and low anchoring efficiency of traditional foundation piles in permafrost areas, improve the bearing capacity and stability of pile foundations in permafrost areas, and ensure the safety and stability of roadbed projects.

[0004] The present invention provides an ice bolt pile for permafrost areas, specifically comprising: an ice bolt pile;

[0005] The ice bolt pile consists of a pile center axis, a connector, a bionic tapered tooth structure, small-diameter threaded blades, a reserved connection hole, and a splicing reinforcement component.

[0006] The central shafts of the pile bodies are all hollow structures, and the upper and lower ends of the central shafts of the pile bodies of the upper group and the top of the central shafts of the pile bodies of the lower group are respectively provided with connecting heads, and four groups of reserved connecting holes are respectively provided on the connecting heads, and the connecting head at the bottom end of the central shafts of the pile bodies of the upper group is docked with the connecting head at the top end of the central shafts of the pile bodies of the lower group, and the reinforced connection is completed by assembling the reinforcement components to the reserved connecting holes. The connecting head at the top end of the central shafts of the pile bodies of the upper group can also be connected to the torque electric motor, and the bottom end of the central shafts of the pile bodies of the lower group is integrated with bionic conical teeth, and the outer peripheral wall of the central shafts of the pile bodies is also provided with small-diameter threaded blades.

[0007] Furthermore, the small-diameter threaded blade adopts a spiral blade with a blade width of 40 to 120 mm, the pitch is reduced to 5 to 8 cm, and a high-density spiral array is formed through topological optimization. The root of the blade is thickened and 3 to 5 mm or 8 to 12 mm ribs are added, and the blade inclination angle is set to 10° to 12°.

[0008] Furthermore, the bionic conical teeth are shaped like a wedge, with a sharp tip like a blade, and the tooth body gradually widens from the tip to the base to form a conical structure. The bionic conical teeth are arranged in an orderly manner around the lower part of the ice bolt pile and are tightly engaged.

[0009] Furthermore, the ice bolt pile adopts a steel-titanium alloy composite structure, with the interior made of ASTMA572 high-strength steel and the outer layer covered with Ti-6Al-4V titanium alloy (thermal expansion coefficient 8.0~9.5×10 -6 / ℃), and gradient composite technology is used, with titanium alloy only used in the upper part of the pile body. Since the upper part of the pile body is "the pile section crossing the active layer, between the surface and the permafrost interface", titanium alloy is needed in this location due to frequent freeze-thaw cycles. The surface microstructure of the pile body is simulated by spraying a super-hydrophobic coating containing polytetrafluoroethylene (PTFE) to reduce the frictional resistance between the pile and the frozen soil during the screw-in stage. However, due to the high water content in the frozen soil area, an anti-corrosion coating needs to be sprayed on the outer surface of the pile body. Different anti-corrosion coating formulas are selected according to different frozen soil environments, and the coating thickness is controlled at 0.2-0.3mm. For less-ice-rich frozen soil (ice content <10%), a three-layer protection system of epoxy zinc-rich primer + epoxy micaceous iron intermediate paint + polyurethane topcoat is adopted; for more-ice-rich frozen soil (ice content 10%-25%), silicone-modified epoxy coating is suitable; for saturated frozen soil (ice content >25%), polyurea coating is preferred; for extremely low-temperature environments with ground temperature below -1℃, organic fluorine coating is used.

[0010] Furthermore, a paraffin-based phase change material (melting point -5°C to 0°C) is embedded in the surface of the ice bolt pile to form a phase change energy storage layer.

[0011] A method for constructing ice bolt piles in permafrost areas, comprising the following steps in sequence:

[0012] (a) Geological exploration and analysis: Detailed measurement of frozen soil thickness, ice content, and ground temperature to provide a basis for pile design;

[0013] (b) Prefabricated pile assembly: Based on the survey data, ice bolt piles of appropriate size are customized and sprayed with super hydrophobic and anti-corrosion coatings;

[0014] (c) Site pretreatment: Before ice bolt pile construction, remove all obstacles above and below ground to ensure a smooth construction surface;

[0015] (d) Measurement and positioning: measuring and placing pile positions according to the designed construction drawings and coordinate grid points;

[0016] (e) Pile position calibration: Determine the pile position on the construction axis, assign pile numbers, and measure the ground elevation of each pile position based on the benchmark. The pile position should be strictly measured and set according to the design drawings, with a deviation of no more than 50mm;

[0017] (f) Screw in the ice bolt pile:

[0018] 1) Put the torque electric motor in place, install the ice bolt pile with bionic conical teeth on the torque electric motor drill bit, align it with the pile position, and control the angle with a square;

[0019] 2) Use the automatic control system of the torque electric motor to strictly control the rotation speed and the drill pipe descent speed, requiring that the spiral blade descends one pitch for each rotation;

[0020] 3) Rotate the ice bolt pile with blades until the top of the pile is 20 cm above the ground, and stop rotating, leaving the pile head for splicing;

[0021] 4) During the screwing process, pay attention to the changes in the stratum at any time, and record the construction torque, screwing depth and other parameters in detail. If screwing is difficult, stop immediately to find the cause and screw again after solving the problem;

[0022] (g) Step-by-step splicing of pile segments:

[0023] 1) After removing the ice bolt pile with bionic conical teeth from the drill bit, it is spliced ​​with the upper ice bolt pile body through the reinforcement assembly;

[0024] 2) Install the connector at the top of the central axis of the upper pile group onto the torque electric motor drill bit and screw it into the soil. The screwing process is the same as in (f);

[0025] 3) It is required to check the control angle with a square every 1m of rotation;

[0026] 4) Repeat this step until the length of the spliced ​​ice bolt pile reaches the designed pile length;

[0027] (h) Clear the frozen soil debris remaining inside the hollow shaft:

[0028] Combination of mechanical crushing and vacuum suction:

[0029] 1) A special small spiral crushing drill is used to extend from the top of the pile into the hollow shaft. The spiral blades are made of high-strength wear-resistant material and have a diameter slightly smaller than the inner diameter of the shaft to avoid damaging the pile body. After starting, the blades rotate at a low speed (10 to 20 rpm) to crush the frozen soil. The low speed can effectively crush high-hardness frozen soil and reduce heat transfer to the frozen soil outside the pile.

[0030] 2) Use the supporting vacuum suction equipment to remove the broken frozen soil debris through the pile top interface. The suction force is precisely controlled at -0.05 to 0.08 MPa, which can effectively remove the debris without disturbing the external frozen soil.

[0031] 3) Install an endoscope on the pile top to monitor the hollow shaft in real time, making it easier to adjust the drilling tool position and suction status;

[0032] (i) Pouring special reinforcement slurry:

[0033] 1) First, pour the low-temperature early-strength concrete prepared with composite antifreeze (containing triethanolamine, sodium nitrite, ethylene glycol), thermal conductivity enhancer graphite powder and sulphoaluminate early-strength cement through a chute to the interface of the lower permafrost layer in the permafrost area;

[0034] 2) After the concrete inside the hollow piles in the permafrost layer is completely hardened, a second pouring of special antifreeze coordinated concrete is required. The concrete is made of early-strength Portland cement as the base material, mixed with polycarboxylate high-efficiency water reducer, rosin thermopolymer air-entraining agent and fiber reinforcement (polypropylene fiber and steel fiber), and a composite antifreeze synergist prepared by triethanolamine, air-entraining agent and polycarboxylate water reducer. The concrete is poured into the hollow piles in the upper active layer section of the permafrost zone until it is flush with the ground surface.

[0035] Furthermore, the length of the ice bolt pile and the diameter-to-length ratio are determined and adjusted according to the working conditions in the permafrost area. In the seasonal permafrost area, due to the shallow freezing depth, the ice bolt pile with a pile diameter of 150 to 200 mm can meet the structural requirements; in the permafrost area, in order to penetrate the active layer and anchor in the permafrost layer, the pile diameter needs to be increased to 200 to 250 mm and the pile length needs to be increased accordingly to ensure the stability of the bearing system.

[0036] The present invention provides an ice bolt pile in permafrost areas and a construction method thereof, which has the following beneficial effects:

[0037] The present invention achieves technical feasibility in permafrost roadbed projects by combining the dual characteristics of ice bolts and spiral steel piles through dual innovations of structural miniaturization and material composites. It solves the key problems of traditional foundation piles in permafrost areas, such as large thermal disturbances, large freeze-thaw cycle impact, and low anchoring efficiency. It significantly improves the efficient compressive performance of the piles in the screw-in stage and the mechanical bite-strengthened pull-out performance in the refreezing period, as well as the bearing capacity and stability in permafrost areas, ensuring the safety and stability of roadbed projects. The application of ice bolt piles with excellent performance in permafrost areas is of extremely important practical significance for promoting the development of roadbed construction in this area and ensuring roadbed safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments are briefly introduced below.

[0039] The drawings described below only relate to some embodiments of the present invention, but are not intended to limit the present invention.

[0040] In the attached figure:

[0041] Figure 1 Shows a schematic diagram of the overall structure of the present invention after construction;

[0042] Figure 2 Shows a schematic diagram of the ice bolt pile structure of the present invention;

[0043] Figure 3 A schematic diagram of the local structure of the connection between the central axes of two groups of ice bolt piles in the present invention is shown;

[0044] Figure 4 The present invention is shown Figure 3 A top view of the structure where two groups of ice bolt pile joints are connected;

[0045] Figure 5 A schematic diagram of the top view of the ice bolt pile connection head of the present invention is shown;

[0046] Figure 6 The diagram shows the incision of ice bolt piles after they are driven into the permafrost region according to the present invention.

[0047] Reference Signs List

[0048] 1. Ice bolt pile; 101. Central axis of the pile body; 102. Connector; 103. Bionic conical teeth; 104. Small-diameter threaded blades; 105. Reserved connection holes; 106. Splicing reinforcement components; 2. Ground surface; 3. Upper active layer in permafrost areas; 4. Lower permafrost layer in permafrost areas; 501. Low-temperature, early-strength concrete; 502. Frost-resistant coordinated concrete. DETAILED DESCRIPTION

[0049] In order to make the purpose, scheme and advantages of the technical solution of the present invention more clear, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of specific embodiments of the present invention. Unless otherwise specified, the terms used herein have the common meanings in the art. The same reference numerals in the drawings represent the same components.

[0050] Example 1: Please refer to Figures 1 to 6 :

[0051] The present invention proposes an ice bolt pile in permafrost areas and a construction method thereof, comprising: an ice bolt pile 1;

[0052] The ice bolt pile 1 is composed of a pile body central axis 101, a connecting head 102, a bionic tapered tooth structure 103, a small-diameter threaded blade 104, a reserved connection hole 105 and a splicing reinforcement component 106;

[0053] The pile body central axis 101 is provided with two or more groups, and all of them are hollow structures. The hollow structure of the pile body central axis 101 not only reduces the weight of the pile body, but also facilitates the discharge of frozen soil during construction, reduces damage to the environment, and achieves the effect of green environmental protection and material saving. At the same time, the hollow axis design enhances the overall rigidity and bending resistance of the pile body, further improves the stability and service life of the pile foundation, and ensures that the pile body can still maintain high strength and stability under extremely low temperatures. When there are two groups, the upper and lower ends of the pile body central axis 101 of the upper group and the top of the pile body central axis 101 of the lower group are respectively provided with connecting heads 102. When there are multiple groups, all the single pile body central axes 101 on the upper side are connected. The upper and lower ends and the top of the pile body central shaft 101 of the lower group are respectively provided with connecting heads 102, and four groups of reserved connecting holes 105 are respectively provided on the connecting heads 102. The connecting head 102 at the bottom of the pile body central shaft 101 of the upper group is docked with the connecting head 102 at the top of the pile body central shaft 101 of the lower group, and the reinforced connection is completed by assembling the reinforcing components 106 into the reserved connecting holes 105. The connecting head 102 at the top of the pile body central shaft 101 of the upper group can also be connected to the torque electric motor. The bottom end of the pile body central shaft 101 of the lower group is integrated with a bionic bevel gear 103, and the outer peripheral wall of the pile body central shaft 101 is also provided with small-diameter threaded blades 104.

[0054] In this embodiment, the small-diameter threaded blades 104 use spiral blades with a blade width of 40 to 120 mm, and the pitch is reduced to 5 to 8 cm. A high-density spiral array is formed through topological optimization. The root of the blade is thickened and 3 to 5 mm or 8 to 12 mm ribs are added. The blade inclination angle is set to 10° to 12°, which can balance the cutting resistance and bearing capacity, increase the pile-frozen soil contact surface and friction. This structure enhances the compressive resistance through mechanical extrusion of the high-density spiral array, and mainly reduces the pull-out resistance by mechanical engagement between the blade and the frozen soil. While improving the anchoring effect, it effectively reduces the thermal disturbance of the frozen soil, ensuring high strength and stability under extremely low temperatures.

[0055] In this embodiment, the bionic conical teeth 103 are shaped like a wedge, with a sharp tip like a blade, and the tooth body gradually widens from the tip to the base to form a conical structure. The bionic conical teeth 103 are arranged in an orderly manner around the lower part of the ice bolt pile 1 and tightly engage with each other, which can enable the ice bolt pile 1 to drill into the permafrost layer more quickly and efficiently, reducing construction time and energy consumption. At the same time, the conical tooth design enhances the bite force and pull-out resistance between the pile body and the permafrost, ensuring efficient anchoring in permafrost areas, showing excellent low disturbance, easy-to-adjust pull-out resistance and recyclable characteristics, ensuring its long-term stability and reliability under the control of permafrost temperature.

[0056] In this embodiment, the ice bolt pile 1 is made of a steel-titanium alloy composite structure. The inner layer is made of ASTMA572 high-strength steel, which can ensure the bearing capacity of the ice bolt pile 1. The outer layer is covered with Ti-6Al-4V titanium alloy (thermal expansion coefficient 8.0-9.5×10 -6 / ℃), and adopt gradient composite technology, only use titanium alloy in the upper range of the pile body, which can control the cost increase within 50%. Since the upper range of the pile body is "the pile section crossing the active layer, between the surface and the permafrost interface", the freeze-thaw cycle is frequent in this location and titanium alloy is needed. The surface microstructure of the ice bolt is imitated on the surface of the pile body, and a super-hydrophobic coating containing polytetrafluoroethylene (PTFE) is sprayed to reduce the frictional resistance between the pile and the frozen soil during the screw-in stage. However, due to the high water content in the frozen soil area, an anti-corrosion coating is sprayed on the outer surface of the pile body, and different anti-corrosion coatings are selected according to different frozen soil environments. Layer formula, for less frozen soil (ice content <10%), a three-layer protection system of epoxy zinc-rich primer + epoxy micaceous iron intermediate paint + polyurethane topcoat is adopted; for more frozen soil (ice content 10% to 25%), silicone modified epoxy coating is suitable; for saturated frozen soil (ice content >25%), polyurea coating is preferred; for extreme low temperature environments with ground temperature below -1°C, organic fluorine coating is used, which shows excellent cold resistance and can ensure the long-term stability of the pile body in different frozen soil environments. The coating thickness is controlled at 0.2 to 0.3 mm, which effectively extends the service life of the pile body and reduces maintenance costs.

[0057] In this embodiment, paraffin-based phase change material (melting point -5°C to 0°C) is embedded in the surface of the ice bolt pile 1 to form a phase change energy storage layer. During construction, the phase change material absorbs friction heat, delays the melting of frozen soil, and reduces thermal disturbances. During use, the phase change material can adjust the temperature of the pile body and the surrounding soil to maintain the stability of the frozen soil.

[0058] In this embodiment, the length of the ice bolt pile 1 and the diameter-to-length ratio are determined according to the working conditions in the frozen soil area. In the seasonal frozen soil area, since the freezing depth is relatively shallow, the ice bolt pile 1 with a pile diameter of 150 to 200 mm can meet the structural requirements; in the permafrost area, in order to penetrate the active layer and anchor in the permafrost layer, the pile diameter needs to be increased to 200 to 250 mm and the pile length needs to be increased accordingly to ensure the stability of the bearing system.

[0059] In the present invention, the construction method of ice bolt piles in permafrost areas comprises the following steps in sequence:

[0060] (a) Geological exploration and analysis: Detailed measurement of frozen soil thickness, ice content, and ground temperature to provide a basis for pile design;

[0061] (b) Prefabricated pile assembly: Based on the survey data, ice bolt piles 1 of appropriate size are customized and sprayed with super hydrophobic and anti-corrosion coatings;

[0062] (c) Site pretreatment: Before the construction of ice bolt pile 1, all obstacles on the ground and underground should be removed to ensure that the construction surface is flat;

[0063] (d) Measurement and positioning: measuring and placing pile positions according to the designed construction drawings and coordinate grid points;

[0064] (e) Pile position calibration: Determine the pile position on the construction axis, assign pile numbers, and measure the ground elevation of each pile position based on the benchmark. The pile position should be strictly measured and set according to the design drawings, with a deviation of no more than 50mm;

[0065] (f) Screw in the ice bolt pile:

[0066] 1) The torque electric motor is in place, and the ice bolt pile 1 with the bionic bevel teeth 103 at the bottom is installed on the torque electric motor drill bit, and aligned with the pile position, and the angle is controlled with a square;

[0067] 2) Use the automatic control system of the torque electric motor to strictly control the rotation speed and the drill pipe descent speed, requiring that the spiral blade descends one pitch for each rotation;

[0068] 3) Rotate the ice bolt pile with blades until the top of the pile is 20 cm above the ground, and stop rotating, leaving the pile head for splicing;

[0069] 4) During the screwing process, pay attention to the changes in the stratum at any time, and record the construction torque, screwing depth and other parameters in detail. If screwing is difficult, stop immediately to find the cause and screw again after solving the problem;

[0070] (g) Step-by-step splicing of pile segments:

[0071] 1) After removing the ice bolt pile 1 with the bionic conical teeth 103 at the bottom from the drill bit, it is spliced ​​with the ice bolt pile body 1 on the upper side through the reinforcement assembly 106;

[0072] 2) Install the connector 102 at the top of the pile center shaft 101 of the upper group onto the torque electric motor drill bit and screw it into the soil. The screwing process is the same as in (f);

[0073] 3) It is required to check the control angle with a square every 1m of rotation;

[0074] 4) Repeat the above steps until the length of the spliced ​​ice bolt pile reaches the designed pile length;

[0075] (h) Clear the frozen soil debris remaining inside the hollow shaft:

[0076] Combination of mechanical crushing and vacuum suction:

[0077] 1) A special small spiral crushing drill is used to extend from the top of the pile into the hollow shaft. The spiral blades are made of high-strength wear-resistant material and have a diameter slightly smaller than the inner diameter of the shaft to avoid damaging the pile body. After starting, the blades rotate at a low speed (10 to 20 rpm) to crush the frozen soil. The low speed can effectively crush high-hardness frozen soil and reduce heat transfer to the frozen soil outside the pile.

[0078] 2) Use the supporting vacuum suction equipment to remove the broken frozen soil debris through the pile top interface. The suction force is precisely controlled at -0.05 to 0.08 MPa, which can effectively remove the debris without disturbing the external frozen soil.

[0079] 3) Install an endoscope on the pile top to monitor the hollow shaft in real time, making it easier to adjust the drilling tool position and suction status;

[0080] (i) Pouring special reinforcement slurry:

[0081] 1) First, a low-temperature early-strength concrete 501 prepared with a composite antifreeze (containing triethanolamine, sodium nitrite, and ethylene glycol), graphite powder as a thermal conductivity enhancer, and sulphoaluminate early-strength cement is poured through a chute to the interface position of the lower permafrost layer 4 in the permafrost area;

[0082] 2) After the concrete inside the permafrost hollow piles is completely hardened, a second pouring of special antifreeze coordinated concrete 502 is required. The concrete is made of early-strength Portland cement as a base material, mixed with polycarboxylate high-efficiency water reducer, rosin thermopolymer air entraining agent and fiber reinforcement (polypropylene fiber and steel fiber), and a composite antifreeze synergist prepared from triethanolamine, air entraining agent and polycarboxylate water reducer. The concrete is poured into the hollow piles in the upper active layer 3 of the permafrost zone until it is flush with the ground surface 2.

[0083] In this article, there are several points to note:

[0084] 1. The drawings of the embodiments of the present invention only relate to the structures related to the embodiments of the present invention. Other structures may refer to conventional designs.

[0085] 2. In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to form new embodiments.

[0086] The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed by the present invention, which should be covered by the scope of protection of the present invention.

Claims

1. An ice bolt pile in permafrost areas, characterized in that: include: Ice Bolt Stake (1); The ice bolt pile (1) is composed of a pile body central axis (101), a connector (102), a bionic tapered tooth structure (103), small-diameter threaded blades (104), a reserved connection hole (105), and a splicing reinforcement component (106); The pile body central shaft (101) is a hollow structure. The upper and lower ends of the pile body central shaft (101) of the upper group and the top of the pile body central shaft (101) of the lower group are respectively provided with connecting heads (102). Four groups of reserved connecting holes (105) are respectively provided on the connecting heads (102). The connecting heads (102) at the bottom end of the pile body central shaft (101) of the upper group are docked with the connecting heads (102) at the top end of the pile body central shaft (101) of the lower group, and the reinforced connection is completed by assembling them into the reserved connecting holes (105). The connecting heads (102) at the top end of the pile body central shaft (101) of the upper group can also be connected to a torque electric motor. The bottom end of the pile body central shaft (101) of the lower group is integrated with a bionic bevel gear (103). Small-diameter threaded blades (104) are also respectively provided on the outer peripheral wall of the pile body central shaft (101).

2. The permafrost region ice bolt pile according to claim 1, characterized in that: The small-diameter threaded blade (104) adopts a spiral blade with a blade width of 40 to 120 mm, a pitch reduced to 5 to 8 cm, a high-density spiral array formed through topological optimization, a thickened blade root and a 3 to 5 mm or 8 to 12 mm rib, and a blade inclination angle set to 10° to 12°.

3. The permafrost region ice bolt pile according to claim 1, characterized in that: The bionic conical teeth (103) are shaped like a wedge, with a sharp tip like a blade, and a tooth body that gradually widens from the tip to the base to form a conical structure. The bionic conical teeth (103) are arranged in order around the lower part of the ice bolt pile (1) and are tightly engaged.

4. The permafrost region ice bolt pile according to claim 1, characterized in that: The ice bolt pile (1) is entirely made of a steel-titanium alloy composite structure, with the interior being made of ASTMA572 high-strength steel and the outer layer being covered with Ti-6Al-4V titanium alloy (thermal expansion coefficient 8.0-9.5×10 -6 / ℃), and adopt gradient composite technology, use titanium alloy only in the upper part of the pile body, imitate the surface microstructure of ice bolts on the surface of the pile body, spray a super hydrophobic coating containing polytetrafluoroethylene (PTFE), and spray an anti-corrosion coating on the outer surface of the pile body. According to different permafrost environments, different anti-corrosion coating formulas are selected, and the coating thickness is controlled at 0.2-0.3mm. For less-ice permafrost (ice content <10%), a three-layer protection system of epoxy zinc-rich primer + epoxy micaceous iron intermediate paint + polyurethane topcoat is adopted; for more-ice permafrost (ice content 10%-25%), silicone-modified epoxy coating is suitable; for saturated permafrost (ice content >25%), polyurea coating is preferred; for extreme low temperature environments with ground temperature below -1℃, organic fluorine coating is used.

5. The permafrost region ice bolt pile according to claim 1, characterized in that: The surface of the ice bolt pile (1) is embedded with a paraffin-based phase change material (melting point -5°C to 0°C) to form a phase change energy storage layer.

6. The method for constructing ice bolt piles in permafrost areas according to claim 1, characterized in that: The steps are as follows: (a) Geological exploration and analysis: Detailed measurement of frozen soil thickness, ice content, and ground temperature to provide a basis for pile design; (b) Prefabricated pile assembly: Based on the survey data, ice bolt piles (1) of appropriate size are customized and sprayed with super hydrophobic and anti-corrosion coatings; (c) Site pretreatment: Before the construction of ice bolt piles (1), all obstacles on the ground and underground should be removed to ensure that the construction surface is flat; (d) Measurement and positioning: measuring and placing pile positions according to the designed construction drawings and coordinate grid points; (e) Pile position calibration: Determine the pile position on the construction axis, assign pile numbers, and measure the ground elevation of each pile position based on the benchmark. The pile position should be strictly measured and set according to the design drawings, with a deviation of no more than 50mm; (f) Screw in the ice bolt pile: 1) The torque electric motor is in place, and the ice bolt pile (1) with the bionic cone teeth (103) at the bottom is installed on the torque electric motor drill bit, and is aligned with the pile position, and the angle is controlled with a square; 2) Use the automatic control system of the torque electric motor to strictly control the rotation speed and the drill pipe descent speed, requiring that the spiral blade descends one pitch for each rotation; 3) Rotate the ice bolt pile with blades until the top of the pile is 20 cm above the ground, and stop rotating, leaving the pile head for splicing; 4) During the screwing process, pay attention to the changes in the stratum at any time, and record the construction torque, screwing depth and other parameters in detail. If screwing is difficult, stop immediately to find the cause and screw again after solving the problem; (g) Step-by-step splicing of pile segments: 1) After the ice bolt pile (1) with the bionic conical teeth (103) at the bottom is removed from the drill bit, it is spliced ​​with the ice bolt pile body (1) at the upper side through the reinforcement component (106); 2) Install the connector (102) at the top of the central axis (101) of the upper pile group onto the torque electric motor drill bit and screw it into the soil. The screwing process is the same as in (f); 3) It is required to check the control angle with a square every 1m of rotation; 4) Repeat this step until the length of the spliced ​​ice bolt pile reaches the designed pile length; (h) Clear the frozen soil debris remaining inside the hollow shaft: Combination of mechanical crushing and vacuum suction: 1) A special small spiral crushing drill is used to extend from the top of the pile into the hollow shaft. The spiral blades are made of high-strength wear-resistant material and have a diameter slightly smaller than the inner diameter of the shaft to avoid damaging the pile body. After starting, the blades rotate at a low speed (10 to 20 rpm) to crush the frozen soil. The low speed can effectively crush high-hardness frozen soil and reduce heat transfer to the frozen soil outside the pile. 2) Use the supporting vacuum suction equipment to remove the broken frozen soil debris through the pile top interface. The suction force is precisely controlled at -0.05 to 0.08 MPa, which can effectively remove the debris without disturbing the external frozen soil. 3) Install an endoscope on the pile top to monitor the hollow shaft in real time, making it easier to adjust the drilling tool position and suction status; (i) Pouring special reinforcement slurry: 1) First, a low-temperature early-strength concrete (501) prepared by a composite antifreeze (containing triethanolamine, sodium nitrite, and ethylene glycol), a thermal conductivity enhancer graphite powder, and sulphoaluminate early-strength cement is poured into the interface of the lower permafrost layer (4) in the permafrost area through a chute; 2) After the concrete inside the permafrost hollow pile is completely hardened, a second pouring of special antifreeze coordinated concrete (502) is required. The concrete is made of early-strength Portland cement as a base material, mixed with polycarboxylic acid high-efficiency water reducer, rosin thermopolymer air entraining agent and fiber reinforcement material (polypropylene fiber and steel fiber), and a composite antifreeze synergist prepared by triethanolamine, air entraining agent and polycarboxylic acid water reducer. The concrete is poured into the hollow pile in the upper active layer (3) of the permafrost zone until it is flush with the ground surface (2).

7. The method for constructing ice bolt piles in permafrost areas according to claim 6, characterized in that: The length of the ice bolt pile (1) is determined and the diameter-to-length ratio is adjusted according to the working conditions in the frozen soil area. In the seasonal frozen soil area, since the frozen depth is relatively shallow, the ice bolt pile (1) adopts a pile diameter of 150 to 200 mm to meet the structural requirements; in the permafrost area, in order to penetrate the active layer and anchor in the permafrost layer, the pile diameter needs to be increased to 200 to 250 mm and the pile length needs to be increased accordingly to ensure the stability of the bearing system.

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