Metro contact passage high permeability confined water sand layer freezing construction method

Abstract

The application relates to the technical field of freezing methods, and discloses a freezing construction method for a high-permeability confined water sand layer of a subway connecting passage, which comprises an outer pipe and an inner pipe, and further comprises a stirring device, an auxiliary freezing device and a discharging device; the stirring device comprises outer spiral blades, a shaft sleeve, a stirring plate, a water outlet hole and a water pump; the shaft sleeve is rotationally connected to the surface of the inner pipe; the outer spiral blades are fixedly connected to the surface of the shaft sleeve; the stirring plate is fixedly connected to the surface of the outer spiral blades; the water outlet hole is arranged in the surface of the inner pipe; and the water pump is installed on the inner wall of the inner pipe. The outer pipe, the inner pipe, the water outlet hole, the shaft sleeve, the outer spiral blades, the stirring plate and the water pump are cooperatively operated, so that the temperatures of the brines at all places are the same, the high-permeability sand layer on the surface of the outer pipe is uniformly cooled, the high-permeability sand layers with different freezing effects are prevented, and the subsequent engineering is not affected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of freezing method, in particular to a freezing construction method for high-permeability confined water sand layer of subway connecting passage. BACKGROUND

[0002] The freezing method is to freeze the water in the land by using artificial refrigeration technology through refrigerant, thereby increasing the strength and stability of the land. The commonly used freezing method for reinforcing stratum in the market is divided into direct type and indirect type.

[0003] The application No. CN201510186011.8 discloses an auxiliary cooling device for freezing construction of subway connecting passage, which comprises cooling pipes laid on the inner wall of the tunnel concrete segment. The cooling pipes are composed of axial straight pipes and circumferential arc pipes. The axial straight pipes are laid side by side at a certain interval along the axial direction of the concrete segment from the top of the concrete segment downward. The circumferential arc pipes are welded at both ends of each axial straight pipe and laid side by side at a certain interval along the circumferential direction of the concrete segment. The adjacent two circumferential arc pipes are connected by high-pressure rubber pipes. The application also discloses an auxiliary cooling method for freezing construction of subway connecting passage, which comprises the following steps: calculating the laying amount of cooling pipes in the opposite side tunnel of the main freezing surface of the freezing hole, laying the cooling pipes, testing the cooling pipes, laying temperature measuring points, filling heat-conducting mortar, and insulating the cooling pipes. The application improves the overall stability and water sealing property of the frozen soil curtain and the safety of the project. However, when the land is frozen, the cooling liquid flows in the pipe to achieve the cooling and freezing of the surrounding land. The water content in the soil around the pipe is not uniform, which causes a slight deviation in the absorbed heat. When the cooling water continues to flow, the temperature of the cooling water behind the land with more absorbed heat is higher, which makes the temperature of the cooling water behind uneven, resulting in uneven freezing effect of the land behind. Therefore, the freezing construction method for high-permeability confined water sand layer of subway connecting passage is proposed to solve the above problems. SUMMARY

[0004] The present application solves the technical problem of uneven freezing effect of the land behind when the land is frozen. The freezing construction method for high-permeability confined water sand layer of subway connecting passage is provided to solve the above problems in the prior art.

[0005] To solve the above technical problems, the technical solution adopted by the present application is as follows: the freezing construction method for high-permeability confined water sand layer of subway connecting passage comprises the following steps:

[0006] Step 1: Insert the outer tube into the highly permeable sand layer and add low-temperature brine into the outer tube;

[0007] Step 2: When the low-temperature brine enters between the outer and inner tubes, the external motor drives the bushing to rotate, which in turn drives the outer spiral blades to rotate. The outer spiral blades rotate and assist the low-temperature brine to flow downwards.

[0008] Step 3: The outer spiral blades will stir the low-temperature brine through the stirring plate on the surface, so that the temperature of the brine is the same everywhere, and ensure that the high-permeability sand layer on the outer surface of the outer tube will be cooled evenly.

[0009] Step 4: The water pump in the inner pipe will draw the low-temperature brine that has completed the heat exchange in the outer pipe into the inner pipe, and then discharge it for cooling to achieve circulation.

[0010] A construction device for freezing high-permeability pressure-bearing sand layers in subway connecting passages includes an outer pipe and an inner pipe, as well as a mixing device, an auxiliary freezing device, and a discharge device. The mixing device includes an outer spiral blade, a bushing, a mixing plate, a water outlet, and a water pump. The bushing is rotatably connected to the surface of the inner pipe, the outer spiral blade is fixedly connected to the surface of the bushing, the mixing plate is fixedly connected to the surface of the outer spiral blade, the water outlet is located on the surface of the inner pipe, and the water pump is installed on the inner wall of the inner pipe. The auxiliary freezing device includes a shaking module and an exchange module. The exchange module is located on the inner wall of the outer pipe, and the shaking module is located on the surface of the exchange module. The discharge device includes a heat insulation module and a discharge module. The heat insulation module is located on the inner wall of the inner pipe, and the discharge module is located on the inner wall of the heat insulation module. When the low-temperature brine enters between the outer and inner pipes, an external motor drives the bushing to rotate, which in turn drives the outer spiral blades to rotate. The rotating outer spiral blades assist the low-temperature brine in flowing downwards. Simultaneously, the outer spiral blades agitate the low-temperature brine through the surface stirring plate, ensuring that the brine temperature is uniform throughout. This ensures that the highly permeable sand layer on the outer surface of the outer pipe is cooled evenly, preventing the formation of highly permeable sand layers with varying freezing effects, which could affect subsequent engineering work. The inner wall of the outer pipe is rotatably connected to the left end of the inner pipe. The input end of the water pump is connected to the outlet hole. The water pump in the inner pipe draws the low-temperature brine that has undergone heat exchange in the outer pipe into the inner pipe, then discharges it for further cooling, thus achieving circulation.

[0011] Preferably, the shaking module includes a limiting plate, a limiting disk fixedly connected to the side of the limiting plate near the outer tube, and a moving rod fixedly connected to the side of the limiting disk away from the limiting plate. The exchange module includes a water collection tank, the side of the water collection tank near the limiting disk fixedly connected to the inner wall of the outer tube. The moving rod has drainage holes on its surface. When the bushing drives the outer spiral blades and the stirring plate to rotate, the stirring plate and the outer spiral blades agitate the low-temperature brine in the outer tube, causing the flow of the low-temperature brine to move the limiting plate. The limiting plate then moves the moving rod via the limiting disk, and the moving rod extends out of the water collection tank, allowing the water collection tank to move through the moving rod. The drain hole in the moving rod is connected to the high-permeability sand layer outside, allowing the water in the collection tank to flow into the high-permeability sand layer, increasing the water content in the high-permeability sand layer and thus enhancing its freezing effect. The collection tank is made of insulating material, which prevents the water in the collection tank from freezing by the low-temperature brine. When working in the high-permeability sand layer with sufficient moisture, there is no need to add water to the collection tank. The surface of the moving rod is slidably connected to the inner wall of the collection tank. A spring is sleeved on the surface of the moving rod, and the two ends of the spring are fixedly connected to the side of the limiting plate away from the limiting plate and the inner wall of the outer tube, respectively. The surface of the moving rod is slidably connected to the inner wall of the outer tube.

[0012] Preferably, the inner wall of the movable rod is provided with a protective device, which includes an absorbent cotton strip. A transmission rod is slidably connected to the inner wall of the absorbent cotton strip. A magnet is fixedly connected to the bottom end of the transmission rod, and a movable block is fixedly connected to the end of the transmission rod away from the magnet. The inner wall of the water collection tank is equipped with an absorbent sponge. When the water content in the highly permeable sand layer is too high, after the movable rod extends out of the water collection tank, the water in the highly permeable sand layer will seep into the absorbent cotton strip in the drain hole. When the movable rod is reset under the action of the spring, the magnet in the movable rod will be attracted by the magnet set on the inner wall of the outer tube and move downward. The magnet will drive the transmission rod to move downward, and the transmission rod will drive the movable block. As the moving block moves downwards, it squeezes the water in the absorbent cotton strip, causing the water to be forced into the absorbent sponge in the water collection tank. This absorbs some of the external moisture into the water collection tank, preventing excessive water from causing the highly permeable sand layer to collapse after freezing and melting. The absorbent cotton strip is installed on the inner wall of the moving rod, and the surface of the moving block is slidably connected to the inner wall of the moving rod. The surface of the transmission rod is also slidably connected to the inner wall of the moving rod. The inner wall of the outer tube is equipped with a magnet, and the magnets are magnetically attracted to each other. The end of the magnet away from the transmission rod is slidably connected to the inner wall of the moving rod via a spring. The absorbent sponge and the absorbent cotton strip are in contact with each other.

[0013] Preferably, the heat insulation module includes a heat insulation pipe, and the discharge module includes a rotating rod. A rotating bar is fixedly connected to the left end of the rotating rod, and an inner spiral blade is fixedly connected to the surface of the rotating rod. When the water pump draws the low-temperature brine from the outer pipe to the inner pipe after the temperature has risen, the heat insulation pipe in the inner pipe can prevent the temperature of the remaining low-temperature brine in the outer pipe from being transferred to the low-temperature brine in the inner pipe, thereby causing the temperature of the low-temperature brine in the outer pipe to rise and affecting the freezing effect of the high-permeability sand layer. During water pumping, the external motor will also drive the rotating rod to rotate, which will drive the inner spiral blade to rotate. The inner spiral blade will lift the water pumped by the water pump upward to prevent the water pump from being insufficient to pump all the water to the ground, thereby affecting the circulation effect of the low-temperature brine. The surface of the heat insulation pipe is fixedly connected to the inner wall of the inner pipe, the surface of the rotating bar is in contact with the inner wall of the heat insulation pipe, and the surface of the inner spiral blade is in contact with the inner wall of the heat insulation pipe.

[0014] The present invention, by adopting the above technical solution, can bring the following beneficial effects:

[0015] 1. The construction method for freezing the high-permeability pressurized sand layer in this subway connecting passage involves the coordinated operation of the outer pipe, inner pipe, water outlet, bushing, outer spiral blade, mixing plate, and water pump. This ensures that the temperature of the brine is the same everywhere, guaranteeing that the high-permeability sand layer on the outer surface of the outer pipe will be cooled evenly. This prevents the formation of high-permeability sand layers with different freezing effects, which could affect subsequent projects.

[0016] 2. The construction method for freezing the high-permeability pressurized sand layer in the subway connecting passage involves the coordinated operation of a water collection tank, a moving rod, a drainage hole, a limiting plate, and a limiting plate. This allows the water in the water collection tank to flow into the high-permeability sand layer, increasing the water content in the high-permeability sand layer and thus enhancing the freezing effect of the high-permeability sand layer.

[0017] 3. The construction method for freezing the highly permeable pressure sand layer in this subway connecting passage uses the coordinated operation of absorbent cotton strips, transmission rods, magnets, moving blocks, and absorbent sponges to absorb some of the external moisture into the water collection tank, preventing the high-permeability sand layer from collapsing due to excessive water after freezing and melting.

[0018] 4. The construction method for freezing the high-permeability pressure-bearing sand layer in this subway connecting passage involves the coordinated operation of the heat insulation pipe, rotating strip, rotating rod, and inner spiral blade. The heat insulation pipe in the inner pipe can prevent the temperature of the remaining low-temperature brine in the outer pipe from being transferred to the low-temperature brine in the inner pipe, which would cause the temperature of the low-temperature brine in the outer pipe to rise and affect the freezing effect of the high-permeability sand layer. Attached Figure Description

[0019] Figure 1 This is a half-sectional view of the outer tube structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0021] Figure 3 This is a half-sectional view of the inner tube structure of the present invention;

[0022] Figure 4 This is a half-sectional view of the water collection tank structure of the present invention;

[0023] Figure 5 This is a half-sectional view of the movable rod structure of the present invention;

[0024] Figure 6 This is a schematic diagram of the rotating rod structure of the present invention.

[0025] In the diagram: 1. Outer pipe; 2. Auxiliary refrigeration device; 21. Water collection tank; 22. Moving rod; 23. Drain hole; 24. Limiting disc; 25. Limiting plate; 3. Protective device; 31. Absorbent cotton strip; 32. Transmission rod; 33. Magnet; 34. Moving block; 35. Absorbent sponge; 4. Discharge device; 41. Insulation pipe; 42. Rotating bar; 43. Rotating rod; 44. Inner spiral blade; 5. Inner pipe; 6. Water outlet; 7. Bushing; 8. Outer spiral blade; 9. Stirring plate; 10. Water pump. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Construction methods for freezing highly permeable, confined water-sand layers in subway connecting passages, such as... Figures 1-6 As shown, it includes the following steps:

[0028] Step 1: Insert the outer tube 1 into the highly permeable sand layer and add low-temperature brine into the outer tube 1;

[0029] Step 2: When the low-temperature brine enters between the outer tube 1 and the inner tube 5, the external motor drives the bushing 7 to rotate, which in turn drives the outer spiral blade 8 to rotate. The outer spiral blade 8 rotates and assists the low-temperature brine to flow downward.

[0030] Step 3: The outer spiral blades 8 will stir the low-temperature brine through the stirring plate 9 on the surface, so that the temperature of the brine is the same everywhere, and ensure that the high-permeability sand layer on the outer surface of the outer tube 1 will be cooled evenly.

[0031] Step 4: The water pump 10 in the inner pipe 5 will draw the low-temperature brine that has completed the heat exchange in the outer pipe 1 into the inner pipe 5, and then discharge it for cooling to achieve circulation.

[0032] The construction device for freezing high-permeability pressure-bearing sandy layers in subway connecting passages includes an outer pipe 1 and an inner pipe 5, as well as a mixing device, an auxiliary freezing device 2, and a discharge device 4. The mixing device includes an outer spiral blade 8, a bushing 7, a mixing plate 9, a water outlet 6, and a water pump 10. The bushing 7 is rotatably connected to the surface of the inner pipe 5, the outer spiral blade 8 is fixedly connected to the surface of the bushing 7, the mixing plate 9 is fixedly connected to the surface of the outer spiral blade 8, the water outlet 6 is opened on the surface of the inner pipe 5, and the water pump 10 is installed on the inner wall of the inner pipe 5. The auxiliary freezing device 2 includes a shaking module and an exchange module. The exchange module is located on the inner wall of the outer pipe 1, and the shaking module is located on the surface of the exchange module. The discharge device 4 includes a heat insulation module and a discharge module. The heat insulation module is located on the inner wall of the inner pipe 5, and the discharge module is located on the inner wall of the heat insulation module. When the low-temperature brine enters between the outer pipe 1 and the inner pipe 5, the external motor drives the bushing 7 to rotate, which in turn drives the outer spiral blade 8 to rotate. The outer spiral blade 8 rotates and assists the low-temperature brine to flow downwards. At the same time, the outer spiral blade 8 stirs the low-temperature brine through the stirring plate 9 on its surface, so that the temperature of the brine is the same everywhere. This ensures that the high-permeability sand layer on the outer surface of the outer pipe 1 is cooled evenly, preventing the formation of high-permeability sand layers with different freezing effects, which would affect subsequent projects. The inner wall of the outer pipe 1 is rotatably connected to the left end of the inner pipe 5. The input end of the water pump 10 is connected to the outlet hole 6. The water pump 10 in the inner pipe 5 will draw the low-temperature brine that has completed the heat exchange in the outer pipe 1 into the inner pipe 5, and then discharge it for cooling to achieve circulation.

[0033] The shaking module includes a limiting plate 25. A limiting disk 24 is fixedly connected to the side of the limiting plate 25 near the outer tube 1, and a moving rod 22 is fixedly connected to the side of the limiting disk 24 away from the limiting plate 25. The exchange module includes a water collection tank 21. The side of the water collection tank 21 near the limiting disk 24 is fixedly connected to the inner wall of the outer tube 1. A drain hole 23 is provided on the surface of the moving rod 22. When the bushing 7 drives the outer spiral blade 8 and the stirring plate 9 to rotate, the stirring plate 9 and the outer spiral blade 8 will agitate the low-temperature brine in the outer tube 1. The flow of the low-temperature brine will drive the limiting plate 25 to move. The limiting plate 25 will drive the moving rod 22 to move through the limiting disk 24. The moving rod 22 will extend out of the water collection tank 21, so that the water collection tank 21 is connected to the high-permeability sand layer outside through the drain hole 23 in the moving rod 22. The flow of water from the collection tank 21 into the highly permeable sand layer increases the water content in the sand layer, thereby enhancing its freezing effect. The collection tank 21 is made of insulating material to prevent the water in it from freezing due to the low-temperature brine. When working in a well-hydrated highly permeable sand layer, there is no need to add water to the collection tank 21. The surface of the moving rod 22 is slidably connected to the inner wall of the collection tank 21. A spring is fitted onto the surface of the moving rod 22, and the two ends of the spring are fixedly connected to the side of the limiting plate 24 away from the limiting plate 25 and the inner wall of the outer tube 1, respectively. The surface of the moving rod 22 is slidably connected to the inner wall of the outer tube 1. The limiting plate 25 is an inclined plate, which can be moved regardless of whether the low-temperature brine applies a tangential force or an axial force to the limiting plate 25.

[0034] The inner wall of the movable rod 22 is equipped with a protective device 3, which includes an absorbent cotton strip 31. A transmission rod 32 is slidably connected to the inner wall of the absorbent cotton strip 31. A magnet 33 is fixedly connected to the bottom end of the transmission rod 32, and a movable block 34 is fixedly connected to the end of the transmission rod 32 away from the magnet 33. An absorbent sponge 35 is installed on the inner wall of the water collection tank 21. When the water content in the highly permeable sand layer is too high, after the movable rod 22 extends out of the water collection tank 21, the water in the highly permeable sand layer will seep into the absorbent cotton strip 31 in the drain hole 23. When the movable rod 22 is reset under the action of the spring, the magnet 33 in the movable rod 22 will be attracted by the magnet set on the inner wall of the outer tube 1 and move downward. The magnet 33 will drive the transmission rod 32 to move downward, and the transmission rod 32 will drive the movable rod 34 to move downward. The moving block 34 moves downward, squeezing the water in the absorbent cotton strip 31 and forcing it into the absorbent sponge 35 in the water collection tank 21. This absorbs some of the external water into the water collection tank 21, preventing the high-permeability sand layer from collapsing due to excessive water after freezing and melting. The absorbent cotton strip 31 is installed on the inner wall of the moving rod 22. The surface of the moving block 34 is slidably connected to the inner wall of the moving rod 22, and the surface of the transmission rod 32 is slidably connected to the inner wall of the moving rod 22. A magnet is provided on the inner wall of the outer tube 1, and the magnet and the magnet 33 are magnetically attracted to each other. The end of the magnet 33 away from the transmission rod 32 is slidably connected to the inner wall of the moving rod 22 through a spring. The absorbent sponge 35 and the absorbent cotton strip 31 are in contact with each other.

[0035] The insulation module includes an insulation pipe 41, and the discharge module includes a rotating rod 43. A rotating bar 42 is fixedly connected to the left end of the rotating rod 43, and an inner spiral blade 44 is fixedly connected to the surface of the rotating rod 43. When the water pump 10 draws the low-temperature brine from the outer pipe 1 to the inner pipe 5 after the temperature rises, the insulation pipe 41 in the inner pipe 5 can prevent the temperature of the remaining low-temperature brine in the outer pipe 1 from being transferred to the low-temperature brine in the inner pipe 5, thereby causing the temperature of the low-temperature brine in the outer pipe 1 to rise and affecting the freezing effect of the high-permeability sand layer. When pumping water, the external motor will also drive the rotating rod 43 to rotate, and the rotating rod 43 will drive the inner spiral blade 44 to rotate. The inner spiral blade 44 will lift the water pumped by the water pump 10 upward to prevent the water pump 10 from being unable to pump all the water to the ground, thereby affecting the circulation effect of the low-temperature brine. The surface of the insulation pipe 41 is fixedly connected to the inner wall of the inner pipe 5, the surface of the rotating bar 42 is in contact with the inner wall of the insulation pipe 41, and the surface of the inner spiral blade 44 is in contact with the inner wall of the insulation pipe 41.

[0036] Working principle: When the low-temperature brine enters between the outer tube 1 and the inner tube 5, the external motor drives the bushing 7 to rotate, which in turn drives the outer spiral blade 8 to rotate. The outer spiral blade 8 rotates and assists the low-temperature brine to flow downward. At the same time, the outer spiral blade 8 stirs the low-temperature brine through the stirring plate 9 on its surface, so that the temperature of the brine is the same everywhere. This ensures that the high-permeability sand layer on the outer surface of the outer tube 1 is cooled evenly, preventing the formation of high-permeability sand layers with different freezing effects, which would affect subsequent projects. Meanwhile, the water pump 10 in the inner tube 5 draws the low-temperature brine that has completed the heat exchange in the outer tube 1 into the inner tube 5, and then discharges it for cooling to achieve circulation.

[0037] When the bushing 7 drives the outer spiral blade 8 and the stirring plate 9 to rotate, the stirring plate 9 and the outer spiral blade 8 will agitate the low-temperature brine in the outer pipe 1. The flow of the low-temperature brine will drive the limiting plate 25 to move. The limiting plate 25 will drive the moving rod 22 to move through the limiting plate 24. The moving rod 22 will extend out of the water collection tank 21, so that the water collection tank 21 is connected to the high-permeability sand layer outside through the drain hole 23 in the moving rod 22. This allows the water in the water collection tank 21 to flow into the high-permeability sand layer, thereby increasing the water content in the high-permeability sand layer and thus increasing the freezing effect of the high-permeability sand layer. The water collection tank 21 is made of heat-insulating material, which can prevent the water in the water collection tank 21 from freezing by the low-temperature brine. When working in the high-permeability sand layer with sufficient moisture, there is no need to add water to the water collection tank 21.

[0038] When the moisture content in the highly permeable sand layer is too high, after the moving rod 22 extends out of the water collection tank 21, the moisture in the highly permeable sand layer will seep into the absorbent cotton strip 31 in the drain hole 23. When the moving rod 22 is reset under the action of the spring, the magnet 33 in the moving rod 22 will be attracted by the magnet set on the inner wall of the outer tube 1 and move downward. The magnet 33 will drive the transmission rod 32 to move downward, and the transmission rod 32 will drive the moving block 34 to move downward. The moving block 34 will squeeze the moisture in the absorbent cotton strip 31, so that the moisture is squeezed out into the absorbent sponge 35 in the water collection tank 21. In this way, some of the moisture from the outside can be absorbed into the water collection tank 21, preventing the highly permeable sand layer from collapsing due to excessive water after freezing and melting.

[0039] When the water pump 10 draws the low-temperature brine from the outer pipe 1 to the inner pipe 5 after the temperature has risen, the heat insulation pipe 41 in the inner pipe 5 can prevent the temperature of the remaining low-temperature brine in the outer pipe 1 from being transferred to the low-temperature brine in the inner pipe 5, which would cause the temperature of the low-temperature brine in the outer pipe 1 to rise and affect the freezing effect of the high-permeability sand layer. When pumping water, the external motor will also drive the rotating rod 43 to rotate, which will drive the inner spiral blade 44 to rotate. The inner spiral blade 44 will lift the water pumped by the water pump 10 upward to prevent the water pump 10 from being unable to pump all the water to the ground, thus affecting the circulation effect of the low-temperature brine.

[0040] This invention provides a method for freezing high-permeability confined water-sand layers in subway connecting passages. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A construction device for freezing high-permeability pressurized water-sand layers in subway connecting passages, comprising an outer pipe (1) and an inner pipe (5), characterized in that: It also includes a stirring device, an auxiliary freezing device (2) and a discharge device (4). The stirring device includes an outer spiral blade (8), a bushing (7), a stirring plate (9), a water outlet (6), and a water pump (10). The bushing (7) is rotatably connected to the surface of the inner tube (5). The outer spiral blade (8) is fixedly connected to the surface of the bushing (7). The stirring plate (9) is fixedly connected to the surface of the outer spiral blade (8). The water outlet (6) is opened on the surface of the inner tube (5). The water pump (10) is installed on the inner wall of the inner tube (5). The auxiliary refrigeration device (2) includes a shaking module and an exchange module. The exchange module is disposed on the inner wall of the outer tube (1), and the shaking module is disposed on the surface of the exchange module. The discharge device (4) includes a heat insulation module and a discharge module. The heat insulation module is disposed on the inner wall of the inner tube (5), and the discharge module is disposed on the inner wall of the heat insulation module. The shaking module includes a limiting plate (25), a limiting disk (24) is fixedly connected to the side of the limiting plate (25) near the outer tube (1), and a moving rod (22) is fixedly connected to the side of the limiting disk (24) away from the limiting plate (25). The exchange module includes a water collection tank (21), the side of the water collection tank (21) near the limiting plate (24) is fixedly connected to the inner wall of the outer pipe (1), and the surface of the moving rod (22) is provided with a drain hole (23). The inner wall of the outer tube (1) is rotatably connected to the left end of the inner tube (5), and the input end of the water pump (10) is connected to the outlet hole (6). The surface of the movable rod (22) is slidably connected to the inner wall of the water collection tank (21). A spring is sleeved on the surface of the movable rod (22), and the two ends of the spring are respectively fixedly connected to the side of the limiting plate (24) away from the limiting plate (25) and the inner wall of the outer tube (1). The surface of the movable rod (22) is slidably connected to the inner wall of the outer tube (1). The inner wall of the movable rod (22) is provided with a protective device (3), the protective device (3) includes a water-absorbing cotton strip (31), the inner wall of the water-absorbing cotton strip (31) is slidably connected to a transmission rod (32), the bottom end of the transmission rod (32) is fixedly connected to a magnet (33), the end of the transmission rod (32) away from the magnet (33) is fixedly connected to a movable block (34), and the inner wall of the water collection tank (21) is equipped with a water-absorbing sponge (35). The absorbent cotton strip (31) is installed on the inner wall of the moving rod (22). The surface of the moving block (34) is slidably connected to the inner wall of the moving rod (22). The surface of the transmission rod (32) is slidably connected to the inner wall of the moving rod (22). The inner wall of the outer tube (1) is provided with a magnet, and the magnet and the magnet (33) are magnetically attracted to each other. The end of the magnet (33) away from the transmission rod (32) is slidably connected to the inner wall of the moving rod (22) through a spring. The absorbent sponge (35) and the absorbent cotton strip (31) are in contact with each other.

2. The construction device for freezing high-permeability confined water-sand layers in subway connecting passages according to claim 1, characterized in that: The heat insulation module includes a heat insulation pipe (41), the discharge module includes a rotating rod (43), the left end of the rotating rod (43) is fixedly connected to a rotating bar (42), and the surface of the rotating rod (43) is fixedly connected to an inner spiral blade (44).

3. The construction device for freezing high-permeability confined water-sand layers in subway connecting passages according to claim 2, characterized in that: The surface of the heat insulation tube (41) is fixedly connected to the inner wall of the inner tube (5), the surface of the rotating strip (42) is in contact with the inner wall of the heat insulation tube (41), and the surface of the inner spiral blade (44) is in contact with the inner wall of the heat insulation tube (41).

4. A method for freezing a high-permeability confined water-sand layer in a subway connecting passage, using the freezing construction device for a high-permeability confined water-sand layer in a subway connecting passage as described in claim 3, characterized in that: Includes the following steps: Step 1: Insert the outer tube (1) into the highly permeable sand layer and add low-temperature brine into the outer tube (1); Step 2: When the low-temperature brine enters between the outer tube (1) and the inner tube (5), the motor of the external device drives the bushing (7) to rotate. The bushing (7) will drive the outer spiral blade (8) to rotate. The outer spiral blade (8) will rotate and assist the low-temperature brine to flow downward. Step 3: The outer spiral blades (8) will stir the low-temperature brine through the stirring plate (9) on the surface, so that the temperature of the brine is the same everywhere, and ensure that the high-permeability sand layer on the outer surface of the outer tube (1) will be cooled evenly. Step 4: The water pump (10) in the inner tube (5) will draw the low-temperature brine that has completed the heat exchange in the outer tube (1) into the inner tube (5) and then discharge it for cooling to achieve circulation.

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