Anti-freezing screw anchor and construction method thereof

Abstract

The invention discloses an anti-freezing and anti-pulling screw anchor and a construction method thereof, and belongs to the field of pile foundation engineering.The anti-freezing and anti-pulling screw anchor comprises an upper pile body, an anti-freezing and anti-pulling mechanism and a screw anchor body, the upper pile body penetrates through the anti-freezing and anti-pulling mechanism and then is in threaded connection with the top end of the screw anchor body, the anti-freezing and anti-pulling mechanism comprises a mounting sleeve, and the side wall of the mounting sleeve is wrapped with a layer of rubber coiled material; the outer side of the rubber coiled material is coated with a layer of asphalt coiled material, limiting grooves are formed in the top end and the bottom end of the mounting sleeve, a plurality of rails are annularly formed in the sides, away from the asphalt coiled material, of the limiting grooves, a sliding block is arranged in each rail in a sliding mode, a spring is fixed to each sliding block, and the free end of each spring is connected with a telescopic sleeve. And a gap exists between the telescopic sleeve and the asphalt coiled material. Frost heaving force can be further counteracted, so that the freezing pulling effect of the spiral anchor in the cold region is reduced, the freezing pulling damage risk is reduced, the service life of the spiral anchor is prolonged, and the later maintenance cost is reduced.

Description

Technical Field

[0001] The invention belongs to the field of pile foundation engineering, and in particular relates to a freeze-pullout resistant spiral anchor and a construction method thereof. Background Art

[0002] With the development of social economy, my country's infrastructure construction is booming. Many infrastructure projects are inevitably constructed in permafrost areas. The soil layers within the frozen depth range of seasonal permafrost areas experience frost heave and thaw settlement with seasonal changes. The frost heave of the soil within the frozen depth will produce freeze-pullout effect on the pile foundation in the permafrost area. The negative friction caused by thawing and subsidence will increase the settlement of the piles, resulting in increased infrastructure operation and maintenance costs. In severe cases, it will also lead to safety accidents such as tilting and cracking of the pile foundation superstructure, seriously affecting the safe use of the superstructure or building.

[0003] The existing Chinese patent: CN117026954A discloses a reinforced spiral pile and construction method for anti-freezing and pulling. This technology fixes the anti-freezing and pulling reinforced pile body in the frozen soil layer. When the frozen soil layer freezes and heaves, the frozen soil acts on the outer wall of the wing plate and the slide tube, so that the slide tube slides up and down on the outer surface of the sleeve with the help of the first ball. The first ball rolls in the first ball groove of the sleeve and the slide tube, which limits the rotation of the slide tube on the outer surface of the sleeve, adapts to the frost heave phenomenon of the frozen soil, alleviates the frozen pulling displacement of the pile foundation, and multiple wing plates can improve the horizontal bearing capacity of the pile foundation. However, after long-term use, with the corrosion and aging of the first ball groove and the first ball and the action of horizontal force, the first ball will deviate from the first ball groove, causing the slide tube and the sleeve to get stuck, causing the anti-freezing and pulling ability of the pile foundation to fail, so it needs to be further improved. Summary of the invention

[0004] The object of the present invention is to provide a freeze-pull-resistant spiral anchor and a construction method thereof to solve the deficiencies in the prior art.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is:

[0006] A freeze-pull resistant spiral anchor comprises: an upper pile body, an anti-freeze-pull mechanism and a spiral anchor body, wherein the upper pile body passes through the anti-freeze-pull mechanism and is threadedly connected to the top end of the spiral anchor body, and the anti-freeze-pull mechanism comprises: a mounting sleeve, the side wall of the mounting sleeve is coated with a layer of rubber coil, the outer side of the rubber coil is coated with a layer of asphalt coil, the top and bottom ends of the mounting sleeve are both provided with limiting grooves, a side of the limiting groove away from the asphalt coil is circumferentially provided with multiple tracks, a slider is slidably arranged in each track, a spring is fixed on the slider, the free end of the spring is connected to a telescopic sleeve, and a gap is provided between the telescopic sleeve and the asphalt coil.

[0007] Furthermore, it also includes a first ball, a first ball groove is opened at the top of the installation sleeve, and a first flange is correspondingly arranged at the top of the upper pile body, and the first flange is rotatably arranged in the first ball groove through the first ball.

[0008] Furthermore, it also includes a second ball, the bottom end of the mounting sleeve is provided with a second ball groove, the top end of the spiral anchor body is correspondingly provided with a protrusion, and the protrusion is rotatably arranged in the second ball groove through the second ball.

[0009] Furthermore, a second flange extends from the bottom of the second ball groove, and the second flange is slidably connected to the spiral anchor body.

[0010] Furthermore, the telescopic sleeve includes: a plurality of arc-shaped plates connected to the springs, and adjacent arc-shaped plates are connected by elastic telescopic materials.

[0011] Furthermore, it also includes a pressure plate, which is fixed on the top of the upper pile body.

[0012] A construction method of a freeze-pull resistant spiral anchor, using any of the spiral anchors described above, comprises the following steps:

[0013] S1. Determine the construction site of the pile foundation, determine the depth of the frozen soil layer, and prefabricate the pile body, anti-freezing and pulling mechanism, and spiral anchor body;

[0014] S2. Drill the spiral anchor body downward into the soil using a drilling rig;

[0015] S3. Place the second ball into the top of the protrusion, place the mounting sleeve into the top of the spiral anchor body, and insert the protrusion into the second ball groove, while the top of the spiral anchor body is slidably connected to the inner side wall of the second flange;

[0016] S4. Place the first ball into the first ball groove, and pass the upper pile body through the mounting sleeve so that the bottom end of the upper pile body is threadedly connected to the top of the spiral anchor body, and insert the first flange into the first ball groove;

[0017] S5. Use the drilling rig to connect to the top of the upper pile body and drive the spiral anchor body to continue to move downward until the antifreeze pull mechanism reaches the frozen soil layer;

[0018] S6. Inject grout into the interior of the upper pile body and the spiral anchor body, and weld the pressure plate to the top of the upper pile body.

[0019] Furthermore, in step S1, after the depth of the frozen soil layer is determined, the length of the prefabricated telescopic sleeve is greater than the depth of the frozen soil layer.

[0020] The invention provides a freeze-pull-resistant spiral anchor and a construction method thereof, which have the following advantages over the prior art:

[0021] 1. The spring and telescopic sleeve slidingly arranged on the inner wall of the limit groove form the first protection, and the rubber coil and asphalt coil coated on the side wall of the installation sleeve form the second protection. When the frozen soil layer frost heaves, the frost heave force first acts on the telescopic sleeve, causing the telescopic sleeve to slide upward in the limit groove or tilt inward; when the telescopic sleeve is tightened and touches the asphalt coil, the asphalt coil and rubber coil are deformed with their good toughness and elasticity, further offsetting the frost heave force, thereby reducing the frost pull effect of the spiral anchor in cold areas, reducing the risk of frost pull damage, extending the service life of the spiral anchor, and reducing the later maintenance cost;

[0022] 2. Since the frost heave forces generated at different positions of the frozen soil layer are different, by setting up multiple arc-shaped plates and connecting them through elastic telescopic materials, it can adapt to the frost heave forces at different positions and cause corresponding deformation, thereby improving the adaptability of the telescopic sleeve and extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 It is a structural schematic diagram of the present invention;

[0025] Figure 2 for Figure 1 Sectional view at AA;

[0026] Figure 3 for Figure 2 A local enlarged view at point B;

[0027] Figure 4 It is a top view of the telescopic sleeve of the present invention.

[0028] In the figure: 1-upper pile body, 2-spiral anchor body, 3-installation sleeve, 4-rubber coil, 5-asphalt coil, 6-limiting groove, 7-spring, 8-telescopic sleeve, 9-first ball, 10-first flange, 11-second ball, 12-protrusion, 13-second flange, 14-arc plate, 15-elastic telescopic material, 16-pressure plate, 17-track, 18-slider. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0030] Example 1

[0031] refer to Figure 1-4As shown, the present invention provides a freeze-drawing resistant spiral anchor, comprising: an upper pile body 1, an anti-freeze-drawing mechanism and a spiral anchor body 2, wherein the upper pile body 1 passes through the anti-freeze-drawing mechanism and is threadedly connected to the top end of the spiral anchor body 2, and the anti-freeze-drawing mechanism comprises: a mounting sleeve 3, the side wall of the mounting sleeve 3 is coated with a layer of rubber coil 4, the outer side of the rubber coil 4 is coated with a layer of asphalt coil 5, the top and bottom ends of the mounting sleeve 3 are both provided with limiting grooves 6, and the limiting groove 6 is circumferentially provided with multiple tracks 17 on the side away from the asphalt coil 5, and a slider 18 is slidably arranged in each track 17, a spring 7 is fixed on the slider 18, and the free end of the spring 7 is connected to a telescopic sleeve 8, and there is a gap between the telescopic sleeve 8 and the asphalt coil 5. The spring 7 and the telescopic sleeve 8 slidingly arranged on the inner wall of the limit groove 6 form the first protection, and the rubber coil 4 and the asphalt coil 5 coated on the side wall of the installation sleeve 3 form the second protection. When frost heaving occurs in the frozen soil layer, the frost heaving force first acts on the telescopic sleeve 8, causing the telescopic sleeve 8 to slide upward in the limit groove 6 or tilt inward; when the telescopic sleeve 8 is tightened and touches the asphalt coil 5, the asphalt coil 5 and the rubber coil 4 are deformed with their good toughness and elasticity, further offsetting the frost heaving force, thereby extending the service life of the spiral anchor and reducing the later maintenance cost.

[0032] As a preferred embodiment, it further comprises a first ball 9, a first ball groove is provided at the top of the installation sleeve 3, a first flange 10 is correspondingly provided at the top of the upper pile body 1, and the first flange 10 is rotatably arranged in the first ball groove by the first ball 9. It further comprises a second ball 11, a second ball groove is provided at the bottom of the installation sleeve 3, a protrusion 12 is correspondingly provided at the top of the spiral anchor body 2, and the protrusion 12 is rotatably arranged in the second ball groove by the second ball 11. When the drilling rig screws the upper pile body 1, the upper pile body 1 and the spiral anchor body 2 continue to move downward as a whole, the first flange 10 and the protrusion 12 roll in the first ball groove respectively with the help of the first ball 9, and the second ball 11 rolls in the second ball groove, so that the installation sleeve 3 only moves vertically downward without rotating around the axis of the drilling rig, so that the antifreeze pull mechanism can easily enter the frozen soil layer, and the feasibility of the entire pile foundation is also improved.

[0033] A second flange 13 extends from the bottom of the second ball groove, and the second flange 13 is slidably connected to the spiral anchor body 2 , thereby improving the rotation stability of the spiral anchor body 2 .

[0034] As a preferred embodiment, the telescopic sleeve 8 includes: a plurality of arc plates 14 connected to the spring 7, and adjacent arc plates 14 are connected by elastic telescopic materials 15, and the elastic telescopic material 15 can be selected from thermoplastic elastomers (TPE). In this embodiment, the number of arc plates 14 is four. Since the frost heave forces generated at different positions of the frozen soil layer are different, by providing a plurality of arc plates 14 and connecting them by elastic telescopic materials 15, it can adapt to the frost heave forces at different positions and cause corresponding deformation, thereby improving the adaptability of the telescopic sleeve 8 and extending the service life.

[0035] As a preferred embodiment, it further comprises a pressure plate 16 , and the pressure plate 16 is fixed on the top end of the upper pile body 1 .

[0036] Example 2

[0037] A construction method of a freeze-resistant spiral anchor comprises the following steps:

[0038] S1. Determine the construction site of the pile foundation and the depth of the frozen soil layer, prefabricate the pile body 1, the anti-freezing and pulling mechanism and the spiral anchor body 2; according to the depth of the frozen soil layer, prefabricate the telescopic sleeve 8 with a length greater than the depth of the frozen soil layer, so that when frost heave occurs, the frozen pulling force acts completely on the outer surface of the curved plate 14;

[0039] S2. Use a drilling rig to drill the spiral anchor body 2 down into the soil;

[0040] S3. The second ball 11 is placed into the top of the protrusion 12, the mounting sleeve 3 is placed into the top of the spiral anchor body 2, and the protrusion 12 is inserted into the second ball groove, while the top of the spiral anchor body 2 is slidably connected to the inner side wall of the second flange 13;

[0041] S4. Place the first ball 9 into the first ball groove, and pass the upper pile body 1 through the mounting sleeve 3 so that the bottom end of the upper pile body 1 is threadedly connected to the top end of the spiral anchor body 2, and insert the first flange 10 into the first ball groove;

[0042] S5. The upper pile body 1 and the spiral anchor body 2 are driven to continue to move downward as a whole by connecting the drilling rig to the top of the upper pile body 1, and the first flange 10 and the protrusion 12 are respectively rolled in the first ball groove by the first ball 9, and the second ball 11 is rolled in the second ball groove, so that the installation sleeve 3 only moves vertically downward without rotating around the axis of the drilling rig, so that the antifreeze pull mechanism can easily enter the frozen soil layer;

[0043] S6. Grouting is performed inside the upper pile body 1 and the spiral anchor body 2 to increase the rigidity of the entire pile foundation; during grouting, only the top of the upper pile body 1 is left exposed on the soil surface, and then a pressure plate 16 is welded to the top of the upper pile body 1 to limit the soil uplift when the pile foundation collapses.

[0044] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0045] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0046] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A freeze-pull resistant spiral anchor, characterized in that: include: An upper pile body (1), an antifreeze pull mechanism and a spiral anchor body (2), wherein the upper pile body (1) passes through the antifreeze pull mechanism and is threadedly connected to the top end of the spiral anchor body (2), and the antifreeze pull mechanism comprises: a mounting sleeve (3), the side wall of the mounting sleeve (3) is coated with a layer of rubber coil (4), the outer side of the rubber coil (4) is coated with a layer of asphalt coil (5), the top and bottom ends of the mounting sleeve (3) are both provided with limiting grooves (6), a side of the limiting groove (6) away from the asphalt coil (5) is provided with a plurality of tracks (17) in a circumferential direction, each track (17) is slidably provided with a slider (18), a spring (7) is fixed on the slider (18), the free end of the spring (7) is connected with a telescopic sleeve (8), and a gap exists between the telescopic sleeve (8) and the asphalt coil (5).

2. A freeze-pull resistant spiral anchor according to claim 1, characterized in that: It also includes a first ball (9), a first ball groove is provided at the top of the mounting sleeve (3), a first flange (10) is correspondingly provided at the top of the upper pile body (1), and the first flange (10) is rotatably arranged in the first ball groove through the first ball (9).

3. A freeze-pull resistant spiral anchor according to claim 1, characterized in that: It also includes a second ball (11), a second ball groove is provided at the bottom end of the mounting sleeve (3), a protrusion (12) is correspondingly provided at the top end of the spiral anchor body (2), and the protrusion (12) is rotatably arranged in the second ball groove through the second ball (11).

4. A freeze-pull resistant spiral anchor according to claim 3, characterized in that: A second flange (13) extends from the bottom of the second ball groove, and the second flange (13) is slidably connected to the spiral anchor body (2).

5. A freeze-pull resistant spiral anchor according to claim 1, characterized in that: The telescopic sleeve (8) comprises: a plurality of arc-shaped plates (14) connected to the spring (7), and adjacent arc-shaped plates (14) are connected via elastic telescopic materials (15).

6. A freeze-pull resistant spiral anchor according to claim 1, characterized in that: It also comprises a pressure plate (16), wherein the pressure plate (16) is fixed on the top end of the upper pile body (1).

7. A method for constructing a frost-resistant spiral anchor, characterized in that: Using the spiral anchor according to any one of claims 1 to 6, comprising the following steps: S1. Determine the construction site of the pile foundation, determine the depth of the frozen soil layer, prefabricate the pile body (1), the antifreeze pull mechanism and the spiral anchor body (2); S2. Drill the spiral anchor body (2) downward into the soil using a drilling rig; S3. Place the second ball (11) into the top of the protrusion (12), place the mounting sleeve (3) into the top of the spiral anchor body (2), and insert the protrusion (12) into the second ball groove, while making the top of the spiral anchor body (2) slidably connected to the inner side wall of the second flange (13); S4. Place the first ball (9) into the first ball groove, and pass the upper pile body (1) through the mounting sleeve (3) so that the bottom end of the upper pile body (1) is threadedly connected to the top end of the spiral anchor body (2), and insert the first flange (10) into the first ball groove; S5. Using a drilling rig connected to the top of the pile body (1), drive the spiral anchor body (2) to continue to move downward until the antifreeze pull mechanism reaches the frozen soil layer; S6. Grouting is performed inside the upper pile body (1) and the spiral anchor body (2), and the pressure plate (16) is welded to the top of the upper pile body (1).

8. The construction method of a freeze-pull resistant spiral anchor according to claim 7, characterized in that: In step S1, after the depth of the frozen soil layer is determined, the length of the prefabricated telescopic sleeve (8) is greater than the depth of the frozen soil layer.

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