Screw anchor capable of reducing installation torque

Abstract

The invention discloses a screw anchor capable of reducing installation torque, and belongs to the technical field of screw anchors, the screw anchor comprises an anchor body and an anti-torsion sleeve coaxially arranged on the outer side of the anchor body in a sleeving mode, the inner wall of the anti-torsion sleeve is in clearance fit with the outer wall of the anchor body, and the anchor body is further provided with an axial force transmission assembly for driving the anti-torsion sleeve to synchronously sink. The torsion-resistant casing pipe is arranged on the outer side of the anchor body, the torsion-resistant casing pipe directly bears lateral pressure of a soil body, and the anchor rod freely rotates in the torsion-resistant casing pipe, so that direct friction between the anchor rod and the soil body is greatly reduced, torque needed for rotating the anchor body is reduced, and distortion and breakage of the anchor rod or damage of driving equipment caused by over-limit torque are effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of spiral anchor technology, and in particular to a spiral anchor that can reduce installation torque. Background Technology

[0002] In existing technologies, the spiral anchor is a pile foundation structure composed of welded spiral blades made of high-strength steel pipes. It provides structural support by spiraling into the soil layer to the bearing stratum, offering advantages such as convenient construction, low cost, and short construction period. Its core advantages include: high degree of mechanization, eliminating the need for earthwork excavation and dewatering, significantly reducing environmental pollution; flexible foundation design improving seismic performance; and excellent bidirectional compressive and tensile strength. It is suitable for various scenarios such as power towers, temporary buildings, and pipeline support.

[0003] The inventors discovered that in relatively hard soils such as dense sand layers and cemented sand, spiral anchors are prone to drilling difficulties, leading to excessive torque. If the torque is forcibly increased during construction, it is very easy to cause the anchor material to twist and deform, or even break. At the same time as the torque is increased, it is also very easy to cause the power of the drive equipment to exceed the limit, or even be damaged, which also puts forward higher requirements for the installation equipment. Excessive torque also means that the soil around the pile will be disturbed too much, which will reduce the bearing capacity of the pile foundation and threaten the safety of the superstructure.

[0004] Therefore, how to effectively reduce the required installation torque in the design of helical anchors is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a spiral anchor that can reduce installation torque.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A spiral anchor that can reduce installation torque includes an anchor body and an anti-torsion sleeve coaxially sleeved on the outside of the anchor body. The inner wall of the anti-torsion sleeve is clearance-fitted with the outer wall of the anchor body and has no radial pressure. The anchor body is provided with an axial force transmission component that drives the anti-torsion sleeve to sink synchronously.

[0007] Preferably, the anchor body includes an anchor rod and an anchor disc fixed to the anchor rod body.

[0008] Preferably, the anchor disc is spirally coiled and fixed to the outer wall of the anchor rod.

[0009] Preferably, the number of anchor discs is at least one, and a plurality of anchor discs, more than one in number, are fixedly connected to the body of the anchor rod at intervals along the length of the anchor rod. The anti-torsion sleeve is segmented to avoid the anchor discs and is sleeved on the body of the anchor rod.

[0010] Preferably, the number of axial force transmission components corresponds to the number of anti-torsion sleeves, and they are fixed to the outer wall of the anchor rod and abut against the end of the corresponding anti-torsion sleeve.

[0011] Preferably, the shape of the axial force transmission component is adapted to the radial cross-section of the anti-torsion sleeve, and its outer periphery is aligned with the outer periphery of the anti-torsion sleeve.

[0012] Preferably, one end of the anchor body has a conical soil-drilling section, and a soil-breaking section is provided on the outer periphery of the soil-drilling section.

[0013] Preferably, the soil-breaking section is a tooth-like structure extending outward from the conical surface of the soil-drilling section in its radial direction.

[0014] Preferably, the space between the anchor body and the anti-torsion sleeve is sealed with a lubricating material.

[0015] Preferably, it is applied to dense sand layers and cemented sand.

[0016] The spiral anchor of this invention, by introducing an anti-torsion sleeve and an axial force transmission component, significantly reduces the torque required during installation while maintaining the original load-bearing capacity of the spiral anchor. Specific technical effects are as follows: 1. In hard soil layers (such as dense sand and cemented sand), the main resistance during the installation of helical anchors comes from the friction between the anchor body and the surrounding soil. This invention addresses this by installing an anti-torsion sleeve on the outside of the anchor body. This sleeve directly bears the lateral pressure from the soil, while the anchor rod rotates freely within the sleeve. This significantly reduces the direct friction between the anchor rod and the soil, lowering the torque required to rotate the anchor body. This effectively prevents anchor rod twisting, breakage, or damage to the drive equipment due to excessive torque.

[0017] 2. The anti-torsion sleeve is sunk synchronously with the anchor body through an axial force transmission component. During service, the axial force transmission component transfers the vertical soil friction resistance experienced by the anti-torsion sleeve to the anchor body, ensuring that the overall bearing capacity of the helical anchor is not reduced due to the introduction of the anti-torsion sleeve. At the same time, the presence of the anti-torsion sleeve can also reduce soil disturbance, maintain the original strength of the soil around the pile, and help improve long-term stability.

[0018] 3. This design is particularly suitable for high-resistance soil layers, expanding the application range of helical anchors. Reduced torque means that less powerful drive equipment can be used, reducing equipment costs and energy consumption, while improving construction speed and safety. Furthermore, the segmented anti-torsion sleeve design can flexibly adapt to multi-anchor structures, ensuring efficient installation under various geological conditions.

[0019] 4. The gap between the anchor body and the anti-torsion sleeve is filled with a lubricating material (such as petroleum jelly or special grease), which not only reduces rotational friction but also prevents fine soil particles from entering the gap, avoiding jamming or wear. The design of the drilling section and the soil breaking section further assists in breaking up the soil ahead, reducing drilling resistance and improving installation smoothness.

[0020] 5. This invention requires no complex external equipment or significant changes to existing construction techniques; the torsional reduction effect can be achieved through structural optimization, resulting in low cost and ease of promotion. Furthermore, by reducing soil disturbance and equipment energy consumption, it aligns with the principles of green construction.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is a structural schematic diagram of Embodiment 1 of the present invention; Figure 2 yes Figure 1 Enlarged view of point A in the middle; Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the present invention; Figure 4 yes Figure 3 Enlarged view of point B in the middle; Figure 5 This is a schematic diagram of the structure of Embodiment 4 of the present invention; Figure 6 yes Figure 5 Enlarged view of point C in the middle; Figure 7 This is a chart of data obtained from laboratory tests of this invention.

[0023] Figure label: 1. Anchor body; 11. Anchor rod; 12. Anchor plate; 2. Anti-torsion sleeve; 3. Axial force transmission component; 4. Soil drilling section; 5. Soil breaking section; 6. Bearing; 7. Lubricating material. Detailed Implementation

[0024] like Figures 1 to 7As shown, this invention provides a spiral anchor that can reduce installation torque, an improvement on the traditional spiral anchor. It mainly includes an anchor body 1, a segmented anti-torsion sleeve 2 fitted outside the anchor body 1, and an axial force transmission component 3 that ensures the synchronous sinking of the anchor body 1 and the anti-torsion sleeve 2. The anchor body 1 consists of an anchor rod 11 and an anchor disc 12. The anchor rod 11 is a long cylindrical straight rod with a smooth outer wall and uniform diameter; one end is tapered, and the other end is used to install a drive device, typically a drilling rig or similar device that provides torque. The anchor disc 12 is a spiral disc structure, coaxially fixed to the outer wall of the anchor rod 11. Driven by the drive device, the anchor body 1 rotates and drills into the ground to provide anchoring. In relatively hard soils such as dense sand layers and cemented sand, auger anchor drilling is difficult, and the torque is easily exceeded. If the torque is forcibly increased during construction, it can easily cause the anchor material to twist and deform, or even break. At the same time, increasing the torque can also easily cause the drive equipment to exceed its power limit, or even be damaged. In addition, excessive disturbance to the soil around the pile can lead to a reduction in the bearing capacity of the pile foundation and threaten the safety of the superstructure. In order to reduce the installation torque, an anti-torsion sleeve 2 is rotatably sleeved on the outer wall of the anchor 11. The anti-torsion sleeve 2 is clearance-fitted with the outer wall of the anchor 11. During the drilling process, the anti-torsion sleeve 2 directly bears the lateral pressure of the soil instead of the outer wall of the anchor 11. The anchor rod 11 rotates freely within the anti-torsion sleeve 2, significantly reducing direct friction between the anchor rod 11 and the soil, lowering the torque required for installation, and effectively preventing anchor rod twisting, breakage, or damage to the drive equipment due to excessive torque. Simultaneously, to ensure the anti-torsion sleeve 2 sinks synchronously with the anchor body 1, an axial force transmission component 3 is specially installed on the anchor rod 11. The axial force transmission component 3 is fixedly connected to the anchor rod 11 and rotates against the end of the anti-torsion sleeve 2. Its specific form can vary, but all must ensure that its outer diameter matches the outer diameter of the anti-torsion sleeve, and that there is both circumferential relative rotation and axial contact with the anti-torsion sleeve. Based on this relationship, as the anchor body 1 sinks with the drilling progress, the axial force transmission component 3 acts on the end of the anti-torsion sleeve 2, generating an axial downward thrust. This causes the anti-torsion sleeve 2 to sink synchronously with the anchor body 1 without affecting the rotation of the anchor rod 11. Specifically, to further reduce installation torque, lubrication is performed in the gap between the anti-torsion sleeve 2 and the anchor rod 11. Lubrication involves installing a bearing 6 between the anti-torsion sleeve 2 and the anchor rod 11, and applying and filling the gap with a lubricating material 7, such as petroleum jelly or a special grease. This not only reduces rotational friction but also prevents fine soil particles from entering the gap, avoiding jamming or wear. Furthermore, to facilitate installation and ensure a constant gap between the anti-torsion sleeve 2 and the anchor rod 11, the contact surface between the axial force transmission component 3 and the anti-torsion sleeve 2 is designed as a stepped surface. This stepped surface can generate axial thrust while also providing radial restraint to the anti-torsion sleeve 2, and it also serves as a guide during installation.

[0025] Specifically, shallow burial depth tests were conducted in the laboratory, and the results were as follows: Figure 7As shown in the chart, at a burial depth of 1.6m, the installation torque of the sleeve-type auger anchor with the same diameter is reduced by nearly 48% compared to the original auger anchor. At this depth, the installation torque of the sleeve-type auger anchor with Vaseline applied is not significantly different from that of the original auger anchor, indicating that Vaseline has not yet played a role. However, as the burial depth increases, after reaching 1.8m, Vaseline begins to have an effect, and the installation torque of the sleeve-type auger anchor with Vaseline applied becomes significantly lower than that of the original auger anchor. At 2.5m, the installation torque of the sleeve-type auger anchor with Vaseline applied is reduced by 26% compared to the original auger anchor.

[0026] It is evident that the technical solution provided by this invention can effectively reduce the installation torque of the spiral anchor.

[0027] The technical solution of the present invention will be further described below through specific embodiments.

[0028] Example 1 This embodiment provides a spiral anchor that can reduce installation torque. It is a spiral anchor for small temporary buildings and is suitable for dense sand layers. The system includes an anchor body 1 and an anti-torsion sleeve 2. The anchor body 1 consists of an anchor rod 11 and an anchor plate 12. The anchor rod 11 is made of a seamless steel pipe with a diameter of 89mm × 6mm and a length of 3.5m. One end is welded with a conical drilling part 4 with a conical angle of 60°. The other end is used to install on the driving equipment and has a corresponding assembly part. For ease of subsequent description, the end of the anchor rod 11 used for assembly is defined as the upper end of the anchor rod 11, and the end with the conical drilling part 4 is defined as the lower end. In this embodiment, there are two anchor plates 12, which are welded to the outer wall of the anchor rod 11 and are located at the lower end and middle end of the anchor rod 11, respectively. The anchor plate 12 is a spiral steel plate structure, and the center line of its spiral coincides with the axis of the anchor rod 11. It is coiled around the outer wall of the welded anchor rod 11, with an outer diameter of 300mm and a thickness of 12mm. Each anchor plate 12 has at least one pitch length along the axial direction of the anchor rod 11, and the spiral directions of the two anchor plates 12 are the same, the lengths are the same, and the starting points are located on the same straight line.

[0029] The anti-torsion sleeve 2 is made of seamless steel pipe with a diameter of 94mm and a diameter of 5mm. It is segmented to avoid the anchor plate 12 welded to the anchor rod 11. In this embodiment, the anti-torsion sleeve 2 is divided into two segments. The first segment is sleeved on the outer wall of the anchor rod 11 from the upper end to the middle anchor plate 12. The second segment is sleeved on the outer wall of the anchor rod 11 from the middle anchor plate 12 to the lower anchor plate 12. The inner wall of the anti-torsion sleeve 2 is clearance-fitted with the outer wall of the anchor rod 11. That is, whether in use or during service, the spiral anchor is in a vertically downward state, and no radial pressure is generated between the inner wall of the anti-torsion sleeve 2 and the outer wall of the anchor rod 11, thereby ensuring the smooth rotation of the anchor body 1.

[0030] Because the inner wall of the anti-torsion sleeve 2 and the outer wall of the anchor rod 11 are in a clearance fit, no axial force is generated between them when the whole is vertically downward. When the driving device drives the anchor body 11 to rotate and gradually drill downward into the ground, it cannot simultaneously drive the anti-torsion sleeve 2 to drill into the ground along with the anchor rod 11. Therefore, an axial force transmission component 3 is additionally provided. The axial force transmission component 3 is fixedly connected to the anchor body 1. Its function is to generate an axial force with the anti-torsion sleeve 2, thereby driving the anti-torsion sleeve 2 to sink synchronously with the anchor body 1. The ends of the axial force transmission component 3 and the anti-torsion sleeve 2 are in a rotating abutment relationship, that is, the relative rotation of the axial force transmission component 3 with the anti-torsion sleeve 2 does not affect Its function is to apply axial thrust to it, causing it to sink synchronously with the anchor body 1. Specifically, in this application, the axial force transmission component 3 is an annular clamp with a thickness of 5mm, an inner diameter of 89mm that is interference-fitted with the anchor rod 11, and an outer diameter of 94mm that is aligned with the outer circumference of the anti-torsion sleeve 2. It is welded to the outer wall of the anchor rod 11. The end of the anti-torsion sleeve 2 is formed with a stepped surface that is adapted to the wall thickness of the anti-torsion sleeve 2 and abuts against the end of the anti-torsion sleeve 2. When the anchor rod 11 rotates and drills into the ground under the drive of the driving device, the annular clamp moves downward synchronously with the anchor rod 11. Under the abutment of the annular clamp, it replaces the anchor rod 11 and generates an axial force between the anti-torsion sleeve 2. In addition, a bearing 6 is rotatably installed between the anchor body 1 and the anti-torsion sleeve 2, and a lubricating material 7, such as petroleum jelly or graphite grease, is sealed and filled to further reduce the relative rotational friction coefficient, reduce the rotational resistance of the anchor body 1 in the anti-torsion sleeve 2, and at the same time form a sealing barrier to prevent sand particles from entering the gap and causing jamming, thus ensuring the long-term effectiveness of torque reduction.

[0031] During installation, a small hydraulic drilling rig is used as the driving device. The drive anchor 1 rotates, which, through the axial force transmission component 3, causes the anti-torsion sleeve 2 to be driven into the soil. The anti-torsion sleeve 2 bears the main lateral pressure of the soil, while the anchor rod 11 rotates freely within the anti-torsion sleeve 2, significantly reducing torque. During the load-bearing phase, the frictional resistance of the soil against the anti-torsion sleeve 2 is transmitted to the anchor 1 through the axial force transmission component 3, maintaining the overall load-bearing capacity.

[0032] Example 2 The difference between this embodiment and Embodiment 1 is that a spiral anchor for transmission tower foundations is provided, suitable for cemented sand. The anchor rod 11 is made of Φ168mm×8mm seamless steel pipe with a length of 8.0m; the drilling part 4 has a cone angle of 45°; the anchor plate 12 is a spiral steel plate with a thickness of 16mm and an outer diameter of 450mm, with a quantity of 3, arranged at 2.0m intervals along the length of the anchor rod 11; the anti-torsion sleeve 2 is made of Φ175mm×7mm seamless steel pipe, with a segmented design, each segment being 1.8m long, for a total of 3 segments, which are respectively fitted between the three anchor plates 12 and on the topmost anchor plate 12; the inner wall of the anti-torsion sleeve 2 is coated with an epoxy resin anti-corrosion layer; the axial force transmission component 3 is a double-piece bolt clamp made of Q355 steel with an inner diameter of 168mm and an outer diameter of 175mm, which is fastened to the anchor rod 11 by 4 M16 bolts; a rubber gasket is set between the clamp and the end of the anti-torsion sleeve 2 for buffering.

[0033] After construction, ground-penetrating radar testing showed that the soil disturbance depth was 12cm, with no damage to the cemented structure; the measured tensile strength was 480kN, meeting the design requirements for the transmission tower foundation.

[0034] Example 3 The difference between this embodiment and Embodiment 1 is that a spiral anchor for pipe support is provided, suitable for the transition layer of dense sand layer and cemented sand. The anchor rod 11 is made of Φ114mm×7mm seamless steel pipe, with a length of 5.0m and a 50° conical angle for the drilling part 4. The anchor plate 12 is a spiral steel plate with a thickness of 14mm and an outer diameter of 380mm. There are two of them, which are arranged at intervals of 1.8m along the length of the anchor rod 11. The anti-torsion sleeve 2 is made of Φ120mm×6mm seamless steel pipe, with a segmented design. Each segment is 2.2m long, and there are two segments in total. They are respectively fitted on the upper and lower parts of the anchor rod 11. The axial force transmission component 3 adopts a ring-shaped welded baffle + reinforcing rib structure. The baffle is 12mm thick and has an outer diameter of 120mm. Each baffle has 4 triangular reinforcing ribs evenly arranged around its circumference and welded to the anchor rod 11 to improve the vertical force transmission efficiency. During the drilling process, the anti-torsion sleeve 2 sank synchronously with a deviation of ≤5° and no skewness, meeting the verticality requirements of the pipeline support; after standing for 6 months, the pull-out bearing capacity was retested and was basically consistent with the initial test value, with no bearing capacity reduction due to soil creep.

[0035] Example 4 The main difference between this embodiment and Embodiment 1 is that a soil-breaking section 5 is additionally provided around the outer periphery of the drilling section 4. Specifically, the soil-breaking section 5 is a toothed structure that starts from the conical surface of the drilling section 4 and extends outward along the radial direction of the drilling section 4. The soil-breaking section 5 pre-breaks the soil in front during drilling, reducing initial resistance. It performs well in extremely hard or cemented soil layers. The drilling section 44 guides the anchor body 1 to directional drilling, and the soil-breaking section 55 breaks down the soil structure. Combined with the torsion reduction effect of the anti-torsion sleeve 2, efficient and safe installation is achieved under harsh geological conditions. This embodiment provides a large-diameter heavy-duty structural spiral anchor suitable for high-strength cemented sand. The anchor rod 11 is made of Φ219mm×10mm seamless steel pipe with a length of 12.0m; the anchor plate 12 is a double-layer spiral steel plate, each layer is 20mm thick, with an outer diameter of 800mm, and there are 4 plates. Anchor rods 11 are spaced 2.5m apart along their length; anti-torsion sleeves 2 are made of Φ228mm×9mm seamless steel pipes, segmented with each segment 2.3m long, for a total of 4 segments; the axial force transmission component 3 uses annular bearing plates and prestressed bolts for connection. The bearing plates are 20mm thick and 228mm in outer diameter. Each bearing plate is secured to anchor rods 11 by 6 M24 prestressed bolts to ensure reliable transmission of vertical force; notably, the drilling section 4 has a 40° conical angle and a length of 400mm; the soil-breaking section 5 has 6 hard alloy tooth-like structures with a tooth height of 60mm and a tooth spacing of 50mm, improving the efficiency of soil breaking and pulverizing. Construction can be completed using a conventional drilling rig, eliminating the need for specialized ultra-high torque equipment, significantly reducing construction costs.

[0036] In summary, the spiral anchor provided by this invention, which can reduce torque, represents a significant improvement over existing technologies.

[0037] In traditional spiral anchor drilling, the anchor body 1 (anchor rod 11 + anchor plate 12) is in direct contact with the soil. The high density of dense sand layers and cemented sand generates extremely strong side friction resistance. The torque must simultaneously overcome the friction of the anchor rod 11 sidewall, the extrusion friction of the anchor plate 12 cutting the soil, and the interlocking resistance between soil particles. This invention achieves a significant reduction in torque through an innovative structure that isolates the anchor body 1 by using an anti-torsion sleeve 2 to allow free rotation. The segmented anti-torsion sleeve 2 avoids the anchor plate 12, which not only does not affect the cutting and drilling function of the anchor plate 12, but also allows the anti-torsion sleeve 2 to fit snugly against the main body of the anchor rod 11, preventing soil from entering the interior of the anti-torsion sleeve 2 through the gaps in the anchor plate 12, thus ensuring a continuous and stable isolation effect.

[0038] The anti-torsion sleeve 2 bears the main lateral earth pressure, isolating the anchor body 1 from the soil. The anchor body 1 only needs to overcome the minor friction of the inner wall of the anti-torsion sleeve 2, rather than directly resisting the strong interlocking resistance of the soil. The installation torque can be reduced by 40%-60%. The reduction in torque directly avoids problems such as torsion deformation and weld cracking caused by excessive torque in the anchor rod 11, and reduces material loss rate, making it particularly suitable for large-diameter, long-rod spiral anchors.

[0039] At the same time, the power requirements of the driving equipment are reduced, and small crawler drilling rigs or conventional construction drilling rigs can be selected, eliminating the need for special ultra-high torque equipment, thus reducing construction costs and equipment transportation difficulties. Furthermore, after construction, the range of soil disturbance is reduced, avoiding local liquefaction of dense sand layers or damage to cemented sand structures, ensuring the stability of the soil around the pile foundation, and indirectly improving the long-term bearing capacity of the pile foundation.

[0040] In addition, to further ensure the smooth operation of the device, an axial force transmission component 3 is set up to realize the vertical force transmission between the anti-torsion sleeve 2 and the anchor body 1. The vertical frictional resistance of the outer periphery of the anti-torsion sleeve 2 is completely transmitted to the anchor body 1 through the axial force transmission component 3, so that the overall pull-out and compressive bearing capacity of the spiral anchor is on par with the traditional structure. The outer periphery of the axial force transmission component 3 is aligned with the anti-torsion sleeve 2 to avoid additional soil scraping resistance during drilling, ensuring that the anti-torsion sleeve 2 sinks smoothly and synchronously without the risk of jamming or deflection.

[0041] Furthermore, in order to combat cemented sand, a combination of a conical drilling section 4 and a toothed soil-breaking section 5 is used to reduce the soil breaking resistance in the early stage of drilling. The toothed structure can cut off the blocky bonds of cemented sand and break the soil into fine particles. Combined with the spiral rise angle of the anchor plate 12, efficient soil removal is achieved, which further assists in reducing torque.

Claims

1. A spiral anchor that can reduce installation torque, characterized in that: It includes an anchor body and an anti-torsion sleeve coaxially sleeved on the outside of the anchor body. The inner wall of the anti-torsion sleeve is clearance-fitted with the outer wall of the anchor body and there is no radial pressure. The anchor body is provided with an axial force transmission component that drives the anti-torsion sleeve to sink synchronously.

2. The spiral anchor with reduced installation torque according to claim 1, characterized in that: The anchor body includes an anchor rod and an anchor disc fixed to the anchor rod body.

3. A spiral anchor with reduced installation torque according to claim 2, characterized in that: The anchor disc is spirally coiled and fixed to the outer wall of the anchor rod.

4. A spiral anchor with reduced installation torque according to claim 3, characterized in that: The number of anchor discs is at least one, and a plurality of anchor discs, more than one in number, are fixedly connected to the body of the anchor rod at intervals along the length of the anchor rod. The anti-torsion sleeve is segmented to avoid the anchor discs and is sleeved on the body of the anchor rod.

5. A spiral anchor with reduced installation torque according to claim 4, characterized in that: The number of axial force transmission components corresponds to the number of anti-torsion sleeves, and they are fixed to the outer wall of the anchor rod and abut against the end of the corresponding anti-torsion sleeve to provide axial force.

6. A spiral anchor with reduced installation torque according to claim 5, characterized in that: The shape of the axial force transmission component is adapted to the radial section of the anti-torsion sleeve, and its outer periphery is aligned with the outer periphery of the anti-torsion sleeve.

7. A spiral anchor with reduced installation torque according to claim 1, characterized in that: One end of the anchor body has a conical soil-drilling section, and a soil-breaking section is provided around the outer periphery of the soil-drilling section.

8. A spiral anchor with reduced installation torque according to claim 7, characterized in that: The soil-breaking section is a tooth-like structure that extends outward from the conical surface of the soil-drilling section in its radial direction.

9. A spiral anchor with reduced installation torque according to claim 1, characterized in that: The space between the anchor body and the anti-torsion sleeve is sealed with lubricating material.

10. A spiral anchor with reduced installation torque according to claim 1, characterized in that: It is applied to dense sand layers and cemented sand.

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