Nested recoverable freezing pipe for inhibiting frost heaving and thaw collapse deformation of soil body and construction method of nested recoverable freezing pipe

Abstract

The invention provides a nested recoverable freezing pipe for inhibiting frost heaving and thaw collapse deformation of a soil body and a construction method thereof.The freezing pipe comprises an inner freezing pipe body and an anchoring sleeve, the inner freezing pipe body is detachably nested in the anchoring sleeve, the anchoring sleeve is provided with a cement paste circulating hole, and a plurality of anchoring assemblies are arranged on the outer wall of the anchoring sleeve; the anchoring assembly comprises at least two movable anchor flukes; the anchoring sleeve comprises a plurality of sleeve branch pipes, every two adjacent sleeve branch pipes are connected through a spring, in every two adjacent sleeve branch pipes, the outer wall of one sleeve branch pipe is hinged to a movable anchor fluke, a sliding way is formed in the movable anchor fluke, an expansion arm is installed on the outer wall of the other sleeve branch pipe in a hinged mode, and the other end of the expansion arm is arranged in the sliding way in a sliding mode. By adjusting the distance between every two adjacent casing branch pipes, the movable anchor flukes can be adjusted to turn up and down. According to the device, frost heaving deformation generated when the soil body is frozen can be restrained, thaw collapse deformation of the soil body after freezing is finished can be restrained, and repeated utilization of the inner freezing pipe can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of urban underground space engineering construction, and in particular relates to a nested recyclable freezing pipe for inhibiting soil frost heave, thaw and sink deformation and a construction method thereof. Background Art

[0002] Artificial freezing method has been widely used in the construction of urban underground space projects. Its most significant advantage is that it can effectively stop water. However, the soil around the frozen pipe will produce frost heave deformation during the freezing stage, and the soil will produce settlement deformation during the melting stage. If the deformation exceeds a certain limit, it will cause the yield fracture of the embedded pipeline and even cause uneven settlement of the ground surface and overturning of surface buildings. Therefore, suppressing the frost heave and thaw settlement deformation of the soil is crucial to construction safety.

[0003] At present, the methods for controlling soil frost heave deformation mainly include controlling freezing temperature (such as intermittent freezing) and grouting, but the effect is not significant and may bring negative effects. For example, the hydration heat generated by grouting will affect the freezing effect of the soil. The method for controlling soil thawing and sinking deformation also mainly adopts the grouting method, but the random distribution of slurry will also cause uneven settlement of the soil. Grouting of soil before and after freezing requires separate grouting pipes. Due to the complexity of the stratum, the diffusion of slurry is random and cannot be controlled. Ineffective grouting engineering events occur from time to time. After freezing construction, the frozen pipes are usually not recycled and directly filled with cement slurry. Few projects use the method of removing the frozen pipes after thawing. These existing measures consume a lot of manpower, material and financial resources, and affect the construction period. Therefore, there is an urgent need for a frozen pipe and its construction method that can not only suppress the frost heave and thaw deformation of the soil, but also realize post-construction recycling. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a nested recyclable freezing pipe and a construction method thereof for inhibiting the frost heave and thaw deformation of the soil. The freezing pipe can not only inhibit the frost heave deformation caused by the freezing of the soil around the freezing pipe, but also inhibit the thaw deformation of the soil after the freezing is completed. The internal freezing pipe can also be reused, which can greatly reduce the potential hazards brought by the artificial freezing method and reduce the construction cost at the same time.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0006] (I) The present invention provides a nested recyclable freezing pipe for suppressing soil frost heave, thaw and sink deformation, comprising an inner freezing pipe and an anchoring sleeve; the inner freezing pipe is used for cold medium circulation, and the inner freezing pipe can be detachably nested in the anchoring sleeve, and the coldness of the cold medium in the inner freezing pipe can be transferred to the soil around the anchoring sleeve; the anchoring sleeve is provided with a cement slurry circulation hole, and when the inner freezing pipe is disassembled and separated from the anchoring sleeve, the cement slurry injected into the anchoring sleeve can flow to the outside of the anchoring sleeve through the cement slurry circulation hole; the outer wall of the anchoring sleeve is provided with a plurality of groups of anchoring assemblies, and the anchoring assemblies include at least two movable anchor claws, and the ends of the movable anchor claws are movably connected to the outer wall of the anchoring sleeve, and the movable anchor claws can be flipped up and down.

[0007] Furthermore, the anchoring sleeve includes a plurality of sleeve branches connected in sequence, and two adjacent sleeve branches are connected by a spring; the number of the anchoring components is consistent with the number of springs and is distributed at the connection between two adjacent sleeve branches; among the two adjacent sleeve branches, the end outer wall of one sleeve branch is hinged to the movable anchor claw, and a slideway is provided on the movable anchor claw, and the end outer wall of the other sleeve branch is hingedly installed with an expansion arm, and the other end of the expansion arm is slidably arranged in the slideway of the movable anchor claw, and the up and down flipping of the movable anchor claw can be adjusted by adjusting the distance between the two adjacent sleeve branches.

[0008] Furthermore, among the plurality of casing branches, the lower end of the casing branch distributed at the bottom is provided with an internal thread, the bottom of the inner freezing pipe is provided with an external thread, and the inner freezing pipe is threadedly connected to the casing branch distributed at the bottom.

[0009] Furthermore, the device is also provided with a nut; the nut is provided with an internal thread, the top of the inner freezing pipe is provided with an external thread, and the nut is threadedly connected to the inner freezing pipe; the outer diameter of the nut is larger than the outer diameter of the anchor sleeve.

[0010] Furthermore, the inner freezing pipe includes a liquid inlet pipe and a liquid outlet pipe, the liquid inlet pipe is nested in the liquid outlet pipe, and the bottom of the liquid inlet pipe is connected to the bottom of the liquid outlet pipe.

[0011] Furthermore, the inner freezing pipe comprises a plurality of inner freezing branch pipes connected in sequence, two adjacent inner freezing branch pipes are threadedly connected, and a sealing rubber ring (20) is provided at the connection; the liquid inlet pipes of two adjacent inner freezing branch pipes are connected, and the liquid outlet pipes of two adjacent inner freezing branch pipes are connected.

[0012] Furthermore, the present invention is also provided with a brine tank and a brine freezing device; the brine tank is provided with a liquid inlet, a liquid outlet, a refrigeration cycle inlet and a refrigeration cycle outlet; the liquid outlet of the brine tank is connected to the liquid inlet pipe, and the liquid inlet of the brine tank is connected to the liquid outlet pipe; a brine pump is provided on the connecting pipe between the brine tank and the liquid inlet pipe; the outlet of the brine freezing device is connected to the refrigeration cycle inlet of the brine tank, and the inlet of the brine freezing device is connected to the refrigeration cycle outlet of the brine tank.

[0013] Furthermore, the movable fluke includes a first anchor rod and a second anchor rod; one end of the first anchor rod is hinged to the outer wall of the anchor sleeve, and the other end is fixedly connected to the second anchor rod, and the angle between the first anchor rod and the second anchor rod is an obtuse angle.

[0014] Furthermore, a conical head is provided at the bottom of the anchoring sleeve.

[0015] (II) The present invention also provides a construction method for nested recyclable freezing pipes for suppressing soil frost heave, thaw and sink deformation, which is based on the above-mentioned nested recyclable freezing pipes and includes the following steps:

[0016] According to the construction drawings, determine the drilling position and carry out the drilling construction; install the inner freezing pipe in the anchor casing, insert it into the hole and reach the designed depth; screw the nut to make the nut move downward relative to the inner freezing pipe, thereby generating downward pressure on the anchor casing and squeezing each spring, so that the distance between two adjacent casing branches becomes smaller, and the expansion arm drives the movable anchor claw to flip outward to form a fan-shaped area in the soil; input cold medium freezing liquid into the liquid inlet pipe of the inner freezing pipe, and it flows out from the liquid outlet pipe to carry out the freezing cycle of the cold medium freezing liquid; after the soil is frozen, remove and separate the inner freezing pipe from the anchor casing; inject cement slurry into the anchor casing, and after the cement slurry enters the anchor casing, it enters the soil layer through the cement slurry circulation hole on the one hand, and enters the fan-shaped area along the spring gap on the other hand, and expands radially outward into the soil; after the grouting pressure reaches the designed value, stop grouting, and after the cement slurry solidifies, the construction is completed.

[0017] Beneficial Effects

[0018] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0019] (1) The present invention can achieve the purpose of anchoring into the soil by providing a multi-section anchoring device embedded in the soil outside. Under the squeezing action of the upper nut, the spring is forced to compress the anchor claw to open, thereby achieving the purpose of anchoring into the soil. At the same time, prestress is applied to the outside of the device. Under the action of each anchoring section, the soil is squeezed from bottom to top, thereby achieving the purpose of suppressing the frost heave deformation of the soil.

[0020] (2) The present invention designs an internal freezing pipe with multiple sections of rotational splicing and arranges a rotating thread at the bottom of the internal freezing pipe to achieve the purpose of mutual disassembly of the internal freezing pipe and the external sleeve, thereby realizing the recycling of the internal freezing pipe and reducing construction costs. At the same time, it reduces the assembly time and steps of the internal freezing pipe and reduces the construction difficulty.

[0021] (3) After the freezing pipe is recovered by the present invention, the multiple sections of anchor sleeves connected together and left in the soil can be directly used as grouting channels, and the cement slurry is directly directed into the soil through the spring gap. In addition, because the spacing between the anchor devices of each section embedded in the soil is the same, the cement slurry can flow into the soil evenly, thereby achieving the purpose of controlling the flow direction and uniformity of the cement slurry, avoiding cement slurry waste, and reducing the construction cost of separate hole drilling and grouting.

[0022] (4) The present invention avoids the disturbance of soil mass caused by drilling and grouting alone, and grouting can be carried out immediately after freezing, thereby reducing construction time and construction cost.

[0023] (5) The fan-shaped area formed by the movable anchor claws pressing down on the soil can guide the cement slurry to flow radially outward into the soil, thereby avoiding the concentration of cement slurry and reducing the grouting effect.

[0024] (6) After grouting, the present invention forms a skeleton to support the soil to prevent soil settlement. At the same time, the anchoring device embedded in the soil plays a supporting role, further reducing melting settlement and achieving the purpose of inhibiting soil deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the freezing system of the present invention;

[0026] Figure 2 This is a top view of the internal freezing pipe of the present invention;

[0027] Figure 3 It is a front view of the anchor sleeve in the uncompressed state of the spring of the present invention;

[0028] Figure 4 It is a front view of the anchor sleeve in the spring compression state of the present invention;

[0029] Figure 5 This is a schematic diagram of the splitting of different sections of the freezing pipe in the present invention;

[0030] Figure 6 This is a schematic diagram of the internal freezing pipe of the present invention;

[0031] Figure 7 It is a schematic diagram of the anchoring sleeve of the present invention;

[0032] Figure 8 Grouting schematic diagram of the present invention;

[0033] The markings in the accompanying drawings are:

[0034] 1-cement slurry flow hole; 2-movable anchor claw; 3-expansion arm; 4-spring; 5-brine flow direction; 6-liquid outlet pipe; 7-liquid inlet pipe; 8-upper thread of inner freezing pipe; 9-nut; 10-brine pump; 11-brine tank; 12-brine freezing device; 13-bottom brine circulation direction; 14-bottom thread of inner freezing pipe; 15-pressing cement slurry into soil; 16-lateral cement slurry diffusion direction; 17-cement slurry flow direction in the pipe; 18-bottom opening cement slurry diffusion direction; 19-movable anchor claw unfolds to form a fan-shaped passage; 20-rubber ring; 21-ungrouted soil. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Reference Figures 1-2 An embodiment of the present invention provides a nested recyclable freezing pipe for suppressing soil frost heave, thaw and sink deformation, including an inner freezing pipe and an anchoring sleeve.

[0037] Wherein, the inner freezing pipe can be detachably nested in the anchoring sleeve, such as Figures 5-6 As shown, the inner freezing pipe includes a plurality of inner freezing branches which are detachably fixedly connected in sequence, two adjacent inner freezing branches are threadedly connected, and a sealing rubber ring (20) is provided at the connection. Each inner freezing branch includes a liquid inlet pipe 7 and a liquid outlet pipe 6, and the liquid inlet pipe 7 is nested in the liquid outlet pipe 6. The liquid inlet pipes 7 of the two adjacent inner freezing branches above and below are connected, and the liquid outlet pipes 6 of the two adjacent inner freezing branches above and below are connected. The liquid inlet pipes 6 of the inner freezing branches distributed at the bottom are connected to the liquid outlet pipe 6.

[0038] The inner freezing pipe is used for cold medium circulation. When in use, the external cold medium circulation liquid (frozen brine) enters the liquid inlet pipe 7 and flows to the bottom of the inner freezing pipe, then enters the liquid outlet pipe 6, and flows out from the top of the inner freezing pipe from bottom to top. The coldness of the cold medium in the liquid outlet pipe 6 can be transferred to the soil around the anchor sleeve to freeze the soil. After the outflowing cold medium is frozen, it enters the inner freezing pipe again to achieve the freezing of the soil.

[0039] like Figure 1As shown, the anchor sleeve is provided with cement slurry circulation holes (the cement slurry circulation holes are distributed at the lower end of the anchor sleeve). When the inner freezing pipe is disassembled and separated from the anchor sleeve, the cement slurry injected into the anchor sleeve can flow to the outside of the anchor sleeve through the cement slurry circulation holes. The outer wall of the anchor sleeve is axially equidistantly provided with three groups of anchor assemblies, each group of anchor assemblies includes two movable anchor claws 2, the ends of the movable anchor claws 2 are movably connected to the outer wall of the anchor sleeve, and the movable anchor claws 2 can be turned up and down.

[0040] Specifically, Figures 3-4 and Figure 7 As shown, the anchoring sleeve includes four sleeve branches connected in sequence (from top to bottom, the first sleeve branch, the second sleeve branch, the third sleeve branch and the fourth sleeve branch, the second sleeve branch and the third sleeve branch have the same length), two adjacent sleeve branches are connected by a spring 4, the upper end of the spring 4 is connected to the sleeve branch distributed above, and the lower end of the spring 4 is connected to the sleeve branch distributed below, the diameter of the spring 4 is larger than the outer diameter of the inner freezing pipe, and the inner freezing pipe runs through each spring 4 at the same time. The number of the springs 4 is consistent with the number of anchoring components, both of which are 3, and the three groups of anchoring components are respectively distributed at the connection of two adjacent sleeve branches.

[0041] like Figures 3-4 and Figure 7 As shown, of the two adjacent casing branches, the outer wall of the end of the casing branch located at the bottom is hinged with the movable anchor claw 2, and a slideway is provided on the movable anchor claw 2, and the outer wall of the end of the casing branch located at the top is hingedly installed with an expansion arm 3, and the other end of the expansion arm 3 is slidably set in the slideway of the movable anchor claw 2, and the end of the expansion arm 3 can rotate in the slideway. By adjusting the spacing between the two adjacent casing branches, the up and down flipping of the movable anchor claw 2 can be adjusted. When the compression spring 4 reduces the spacing between the two adjacent casing branches, the expansion arm 3 can drive the movable anchor claw 2 to flip downward, and when the spring 4 is reset to increase the spacing between the two adjacent casing branches, the expansion arm 3 can drive the movable anchor claw 2 to flip upward and return to its original position.

[0042] As a preferred embodiment of the present invention, Figure 1 As shown, the movable fluke 2 includes a first anchor rod and a second anchor rod, one end of the first anchor rod is hinged to the outer wall of the anchor sleeve, and the other end is fixedly connected to the second anchor rod, and the angle between the first anchor rod and the second anchor rod is an obtuse angle.

[0043] like Figure 3 and 6As shown, among several casing branches, the lower end of the casing branch distributed at the bottom is provided with an internal thread, the bottom of the inner freezing pipe (the lower end of the inner freezing branch distributed at the bottom) is provided with an external thread, and the inner freezing pipe is threadedly connected with the casing branch distributed at the bottom to realize a detachable fixed connection between the inner freezing pipe and the anchoring casing. In addition, a conical head is provided at the bottom of the anchoring casing.

[0044] like Figures 1 to 4 As shown, a nut 9 is provided at the top of the inner freezing pipe, and the nut 9 is provided with an internal thread. The top of the inner freezing pipe (the upper end of the inner freezing branch pipe distributed at the top) is provided with an external thread. The nut 9 is threadedly connected to the inner freezing pipe, and the outer diameter of the nut 9 is larger than the outer diameter of the anchor sleeve. When the nut 9 is rotated and lowered relative to the inner freezing pipe, the outer edge of the nut 9 can generate downward pressure on the anchor sleeve, thereby adjusting the distance between two adjacent sleeve branches.

[0045] As a preferred embodiment of the present invention, Figure 1 As shown, the device is also provided with a brine tank 11 and a brine freezing device 12. Among them, the brine tank 11 is provided with a liquid inlet, a liquid outlet, a freezing cycle inlet and a freezing cycle outlet. The liquid outlet of the brine tank 11 is connected to the liquid inlet pipe 7, the liquid inlet of the brine tank 11 is connected to the liquid outlet pipe 6, and a brine pump 10 is provided on the connecting pipe between the brine tank 11 and the liquid inlet pipe 7. The outlet of the brine freezing device 12 is connected to the freezing cycle inlet of the brine tank 11, and the inlet of the brine freezing device 12 is connected to the freezing cycle outlet of the brine tank 11. When used, the frozen brine in the brine tank 11 enters the liquid inlet pipe 7 and the liquid outlet pipe 6 and freezes the soil. The brine after transferring the cold energy is returned to the brine tank 11. At the same time, the brine in the brine tank 11 enters the brine freezing device 12 for freezing. After being frozen, the brine returns to the brine tank 11 again to experiment the cyclic application of frozen brine.

[0046] The above-mentioned construction method of nested recyclable freezing pipes for suppressing soil frost heave, thaw and sink deformation comprises the following steps:

[0047] Step 1: Calculate the expected freezing area according to the requirements of the construction drawings, determine the specific freezing pipe location, and then perform drilling construction based on the determined location.

[0048] Step 2: transport the components of the device to the construction site, screw and assemble the internal freezing branches into an integrated internal freezing pipe; weld the sleeve branches to the springs, and weld the anchoring components to the outer wall of the sleeve branches to obtain an integrated anchor sleeve. The multi-section component design avoids damage to the freezing pipe due to collisions during transportation after assembly in the factory, while reducing the total length of a single component, facilitating transportation while reducing transportation costs.

[0049] Step 3. Place the assembled inner freezing pipe into water, inject air with a certain pressure (greater than atmospheric pressure) into it, and observe whether bubbles are generated on the surface of the inner freezing pipe. If there are no bubbles, proceed to the next step of construction. If bubbles are generated, mark the location of the bubbles and handle them uniformly. After the air tightness meets the requirements, proceed to the next step of construction to avoid brine leakage.

[0050] Step 4: Install the assembled inner freezing pipe in the anchor sleeve, insert it into the hole and reach the designed depth.

[0051] Step 5: When the bottom of the freezing pipe reaches the designed depth, screw the nut 9 to move it downward relative to the inner freezing pipe, thereby generating downward pressure on the anchor sleeve and squeezing each spring 4. The distance between two adjacent sleeve branches becomes smaller, and the expansion arm 3 drives the movable anchor claw 2 to flip outward. When the nut 9 can no longer rotate, it means that the movable anchor claw is fully opened, squeezing the soil and forming a fan-shaped area in the soil. During this period, force is applied to the tail of the freezing pipe to prevent the freezing pipe from moving outward from the hole due to the opening of the movable anchor claw.

[0052] Step 6: Input cold medium freezing liquid into the liquid inlet pipe 7 of the inner freezing pipe, and it flows out from the liquid outlet pipe 6, enters the brine pump, passes through the brine tank, and enters the brine freezing device. The frozen brine passes through the brine tank to the liquid inlet to complete the freezing cycle.

[0053] Step 7: After the soil freezing construction is completed, the inner freezing pipe is removed from the anchor sleeve for the next freezing construction;

[0054] Step 8: Inject cement slurry with strong fluidity into the anchor casing, such as Figure 8 As shown in the figure, after the cement slurry enters the anchor casing, it enters the soil layer through the cement slurry flow hole on the one hand, and enters the fan-shaped area along the spring gap on the other hand, and radially expands outward to the voids in the soil layer, which plays a role in guiding the flow of cement slurry and avoiding the concentration of cement slurry and reducing the grouting effect;

[0055] Step 9. During the grouting process, as the soil voids are gradually filled, the resistance continues to increase, and the grouting pressure also rises. When the grouting pressure reaches the designed grouting final pressure of 2-3MPa, and the grouting pressure stabilizes within this range for a certain period of time, the grouting is considered to be nearly completed. This stabilization time is usually determined based on engineering experience and specific formation conditions, generally 10 to 30 minutes, and then the grouting is stopped. After the cement slurry solidifies, the skeleton supporting the soil formed by radially expanding outward along the entire outside of the pipeline can prevent soil deformation. At the same time, the cement slurry solidified in the pipe sleeve can also achieve the purpose of supporting the soil to prevent melting and deformation. Construction is completed.

[0056] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A nested recyclable freezing pipe for inhibiting soil frost heave, thaw and sink deformation, characterized in that: Including inner freezing pipe and anchoring sleeve; The inner freezing pipe is used for cold medium circulation, and the inner freezing pipe can be detachably nested in the anchor sleeve, and the cold energy of the cold medium in the inner freezing pipe can be transferred to the soil around the anchor sleeve; The anchor sleeve is provided with a cement slurry flow hole, and when the inner freezing pipe is disassembled and separated from the anchor sleeve, the cement slurry injected into the anchor sleeve can flow to the outside of the anchor sleeve through the cement slurry flow hole; The outer wall of the anchoring sleeve is provided with a plurality of groups of anchoring components, and the anchoring components include at least two movable anchor claws (2). The ends of the movable anchor claws (2) are movably connected to the outer wall of the anchoring sleeve, and the movable anchor claws (2) can be turned upside down.

2. The nested recyclable freezing pipe for suppressing soil frost heave, thaw and sink deformation according to claim 1 is characterized in that: The anchoring sleeve comprises a plurality of sleeve branches connected in sequence, and two adjacent sleeve branches are connected by a spring (4); The number of the anchoring components is consistent with the number of springs (4), and they are distributed at the connection between two adjacent casing branches; The outer wall of the end of one of the two adjacent casing branches is hinged to the movable anchor claw (2), and a slideway is provided on the movable anchor claw (2); the outer wall of the end of the other casing branch is hinged to an expansion arm (3), and the other end of the expansion arm (3) is slidably arranged in the slideway of the movable anchor claw (2); and by adjusting the distance between the two adjacent casing branches, the up and down flipping of the movable anchor claw (2) can be adjusted.

3. The nested recyclable freezing pipe for suppressing soil frost heave, thaw and sink deformation according to claim 2 is characterized in that: Among the plurality of casing branches, the lower end of the casing branch distributed at the bottom is provided with an internal thread, the bottom of the inner freezing pipe is provided with an external thread, and the inner freezing pipe is threadedly connected with the casing branch distributed at the bottom.

4. The nested recyclable freezing pipe for suppressing soil frost heave, thaw and sink deformation according to claim 2 is characterized in that: A nut (9) is also provided; The nut (9) is provided with an internal thread, the top of the inner freezing pipe is provided with an external thread, and the nut (9) is threadedly connected to the inner freezing pipe; the outer diameter of the nut (9) is greater than the outer diameter of the anchor sleeve.

5. The nested recyclable freezing pipe for suppressing soil frost heave, thaw and sink deformation according to claim 2 is characterized in that: The inner freezing pipe comprises a liquid inlet pipe (7) and a liquid outlet pipe (6), wherein the liquid inlet pipe (7) is nested in the liquid outlet pipe (6), and the bottom of the liquid inlet pipe (6) is communicated with the bottom of the liquid outlet pipe (6).

6. The nested recyclable freezing pipe for suppressing soil frost heave, thaw and sink deformation according to claim 5 is characterized in that: The inner freezing pipe comprises a plurality of inner freezing branch pipes connected in sequence, two adjacent inner freezing branch pipes are threadedly connected, and a sealing rubber ring (20) is provided at the connection; The liquid inlet pipes (7) of two adjacent inner freezing branch pipes are connected, and the liquid outlet pipes (6) of two adjacent inner freezing branch pipes are connected.

7. The nested recyclable freezing pipe for suppressing soil frost heave, thaw and sink deformation according to claim 5 is characterized in that: A brine tank (11) and a brine freezing device (12) are also provided; The brine tank (11) is provided with a liquid inlet, a liquid outlet, a refrigeration cycle inlet and a refrigeration cycle outlet; The liquid outlet of the salt water tank (11) is connected to the liquid inlet pipe (7), and the liquid inlet of the salt water tank (11) is connected to the liquid outlet pipe (6); a salt water pump (10) is provided on the connecting pipe between the salt water tank (11) and the liquid inlet pipe (7); The outlet of the brine freezing device (12) is connected to the refrigeration cycle inlet of the brine tank (11), and the inlet of the brine freezing device (12) is connected to the refrigeration cycle outlet of the brine tank (11).

8. The nested recyclable freezing pipe for suppressing soil frost heave, thaw and sink deformation according to claim 2 is characterized in that: The movable fluke (2) comprises a first anchor rod and a second anchor rod; One end of the first anchor rod is hinged to the outer wall of the anchor sleeve, and the other end is fixedly connected to the second anchor rod, and the angle between the first anchor rod and the second anchor rod is an obtuse angle.

9. The nested recyclable freezing pipe for suppressing soil frost heave, thaw and sink deformation according to claim 2, characterized in that: The bottom of the anchoring sleeve is provided with a conical head.

10. The construction method of nested recyclable freezing pipes for suppressing soil frost heave, thaw and sink deformation as claimed in claim 1, characterized in that: The following steps are involved: According to the construction drawings, determine the drilling position and carry out drilling construction; Install the inner freezing pipe in the anchor casing, insert it into the hole and reach the designed depth; The nut (9) is screwed to move the nut (9) downward relative to the inner freezing pipe, thereby generating downward pressure on the anchor sleeve and squeezing each spring (4), so that the distance between two adjacent sleeve branches becomes smaller, and the expansion arm (3) drives the movable anchor claw (2) to turn outward, forming a fan-shaped area in the soil; A cold medium freezing liquid is input into the liquid inlet pipe (7) of the inner freezing pipe, and flows out from the liquid outlet pipe (6), thereby performing a freezing cycle of the cold medium freezing liquid; After the soil is frozen, the inner freezing pipe is removed and separated from the anchoring sleeve; Inject cement slurry into the anchor sleeve. After entering the anchor sleeve, the cement slurry enters the soil layer through the cement slurry flow hole, enters the fan-shaped area along the spring gap, and radially expands outward into the soil. After the grouting pressure reaches the design value, stop grouting, and complete the construction after the cement slurry solidifies.

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