Frost damage prevention and control structure for pile-supported embankment in seasonal frozen area

Abstract

The invention discloses a frost damage prevention and control structure for a pile-supported embankment in a seasonal frozen area, which belongs to the field of foundation engineering and comprises a pile net system, a water-rich system, a pressure guiding system and a subgrade bed. The rich water system comprises a sand layer and a rich water drainage pipe; the sand layer is laid on the pile net system; one end of the water-rich drainage pipe is arranged at the bottom of the sand layer, and the other end of the water-rich drainage pipe is communicated with the outside; the pressure guiding system comprises a pressure guiding cavity and a pressure guiding pipe; the pressure guide cavity is arranged on the sand layer, and the bottom is waterproof and breathable; the subgrade bed is laid on the pressure guiding cavity; the upper end of the pressure guiding pipe is arranged on the road surface at the top of the subgrade bed; the pressure drawing cavity forms a pressure difference by utilizing the air velocity change caused when a vehicle travels on a road surface, so that the pile net system and water below the pile net system are enriched towards a sand layer; after the pressure difference disappears, the enriched water is discharged through the rich water drainage pipe. According to the method, the pot cover effect can be avoided, and the influence of water enrichment on the pile-supported reinforced embankment is reduced.

Description

Technical Field

[0001] The invention belongs to the field of foundation engineering, and relates to a pile-supported embankment structure in a seasonally frozen area, and in particular to a frost damage prevention and control structure of a pile-supported embankment in a seasonally frozen area. Background Art

[0002] The pot-lid effect is the main reason for the reduction of the service life of roadbeds in cold and arid areas. Studies have shown that the pot-lid effect of roadbeds in cold and arid areas is caused by the migration of gaseous water into ice under the temperature gradient. At this time, the moisture content of the soil under the cover layer increases sharply and approaches saturation. When the temperature rises, the solid water turns into liquid water, the bearing capacity of the roadbed decreases, and the embankment disease phenomenon is induced. With the development of the cold and arid areas in northwest my country, the economic losses caused by embankment diseases induced by the pot-lid effect are increasing rapidly. Therefore, a method that can inhibit or even eliminate the pot-lid effect is proposed, which is of great significance to prolong the service life of embankments in cold and arid areas, ensure transportation safety, and accelerate economic development in cold and arid areas.

[0003] The current treatment methods for the pot lid effect are mainly divided into two categories, hydrophobic and water-proof, according to the emphasis. Among them, the Chinese patent applications with patent publication numbers CN117888405A and CN117166307A respectively proposed two hydrophobic solutions; the Chinese patent application with patent publication number CN117888405A opened air vents on the surface to achieve water vapor discharge and avoid water enrichment; the Chinese patent application with patent publication number CN117166307A set up a temperature control layer and modified roadbed fillers to inhibit water freezing and weaken capillary action to avoid the pot lid effect. The Chinese patents with authorization announcement numbers CN215051696U and CN110387781B respectively proposed two water-proof solutions, both of which added a barrier layer to change the water vapor migration path, achieve early enrichment and discharge of water, and weaken the pot lid effect. However, in areas with poor geological conditions, pile-supported reinforced embankments are often used. Affected by uneven settlement, structures such as the temperature control layer and the barrier layer are very prone to tearing, breaking, and other damage, causing the structure to lose its original function. Summary of the invention

[0004] In view of the problems of the prior art, the present invention provides a frost damage prevention and control structure for pile-supported embankments in seasonally frozen areas, which can avoid the occurrence of a pot cover effect and reduce the impact of moisture enrichment on pile-supported reinforced embankments.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A pile-supported embankment frost damage prevention and control structure in a seasonally frozen area, comprising a pile-net system, a water-enriched system, a pressure-drawing system and a roadbed; the pile-net system is a supporting structure fixed to the ground surface, that is, a supporting force-transmitting structure embedded in the soil below the ground surface and partially exposed to the ground surface; the water-enriched system comprises a sand layer and a water-enriched drainage pipe; the sand layer is laid on the pile-net system; one end of the water-enriched drainage pipe is arranged at the bottom of the sand layer, and the other end is communicated with the outside world, so as to discharge the water in the sand layer from the inside to the outside in a one-way manner; the pressure-drawing system comprises a pressure-drawing chamber and a pressure-drawing pipe; the pressure-drawing chamber is arranged on the sand layer, and the bottom is water-proof and breathable; the roadbed is laid on the pressure-drawing chamber; the lower end of the pressure-drawing pipe is connected to the pressure-drawing chamber, and the upper end is arranged on the road surface at the top of the roadbed, so as to communicate with the outside world; the pressure-drawing chamber uses the change in air velocity caused by the passage of vehicles on the road surface to form a pressure difference, so that the water in the pile-net system and the water below it is enriched in the sand layer; after the pressure difference disappears, the enriched water is discharged through the water-enriched drainage pipe.

[0007] To optimize the above technical solutions, the specific measures taken also include:

[0008] Furthermore, the sand layer is a phase change sand layer, which is composed of uniformly mixed capsule phase change material and sand.

[0009] Furthermore, the water-rich system also includes a barrier layer; the barrier layer is made of air-proof and water-proof material and is laid on the outside of the pile-net system above the sand layer and the ground surface.

[0010] Furthermore, the water-rich drainage pipe includes a water-rich drainage pipe body, a self-weight sealing plug and a sand-blocking net; the water-rich drainage pipe body passes through the pile-net system, with the upper end arranged at the bottom of the sand layer and the lower end arranged at the side of the pile-net system; the self-weight sealing plug is arranged at the lower end of the water-rich drainage pipe body, and is rotatably connected to the upper side of the lower end of the water-rich drainage pipe body, and covers the outside of the end of the water-rich drainage pipe body by its own weight; when a pressure difference is formed in the pressure-drawing chamber, the water-rich drainage pipe body is sealed by the self-weight sealing plug, and after the pressure difference disappears, the self-weight sealing plug is opened under the action of water; the sand-blocking net is fixed at the upper end of the water-rich drainage pipe body to prevent the sand layer material from being discharged outward with the water; water-rich drainage pipes are provided on both sides of the bottom of the sand layer.

[0011] Furthermore, the number of the pressure-inducing chambers is one or multiple independent ones; the pressure-inducing chamber is equipped with a pressure-inducing drainage pipe; one end of the pressure-inducing drainage pipe is arranged at the bottom of the pressure-inducing chamber, and the other end is connected to the outside, so as to discharge the accumulated water in the pressure-inducing chamber from the inside to the outside in a unidirectional manner.

[0012] Furthermore, the upper and lower ends of the pressure-inducing pipe are both bell-mouthed, and the lower end is seamlessly connected to the pressure-inducing cavity.

[0013] Furthermore, the road surface on top of the roadbed is paved with railway tracks; the number of the pressure chambers is equal to and corresponds to the number of railway tracks, and the upper end of the pressure pipe of the pressure chamber is arranged between the double tracks of the corresponding railway track; the upper end of the pressure pipe protrudes from the road surface and is lower than the top surface of the railway track.

[0014] Furthermore, the road surface on top of the roadbed is a highway; the number of the pressure chambers is equal to and corresponds to the number of lanes of the highway, and the upper end of the pressure pipe of the pressure chamber is arranged in the middle of the corresponding lane.

[0015] Furthermore, the pressure-inducing chamber is formed by the lower shell surface of the chamber and the upper shell surface of the chamber; the lower shell surface of the chamber is composed of a hollow rigid support and a waterproof and breathable membrane covering it; the lower shell surface of the chamber is a curved surface; the pressure-inducing drainage pipe is connected to the lowest point of the lower shell surface of the chamber; the upper shell surface of the chamber is in the shape of a trumpet with a wide mouth facing downward; the lower end of the pressure-inducing pipe is connected to the top end of the upper shell surface of the chamber; if there are multiple pressure-inducing chambers, multiple pressure-inducing chambers share the same lower shell surface and upper shell surface of the chamber, and the upper shell surface of the chamber is separated into multiple independent pressure-inducing chambers by a concave surface.

[0016] Furthermore, the pressure-drawing drainage pipe comprises a pressure-drawing drainage pipe body and a sealing assembly; the pressure-drawing drainage pipe body passes through the sand layer, the upper end of which is arranged at the bottom of the pressure-drawing drainage chamber, and the lower end is arranged at the side of the sand layer; the sealing assembly comprises an annular hoop, a trapezoidal plug and a plurality of rebound strips; the pressure-drawing drainage pipe body comprises a vertical section and an inclined section; the annular hoop is fixed in the vertical section of the pressure-drawing drainage pipe body, and the inner diameter gradually increases from top to bottom; the trapezoidal plug is arranged in the annular hoop; the rebound strip is V-shaped, passes through the trapezoidal plug, and is fixed to the annular hoop at both ends; the inner diameter of the lower end of the annular hoop is equal to the outer diameter of the lower end of the trapezoidal plug, and the inner diameter of the upper end is smaller than the outer diameter of the upper end of the trapezoidal plug; when a pressure difference is formed in the pressure-drawing chamber, the annular hoop is sealed by the trapezoidal plug under the tension of the rebound strip; after the pressure difference disappears, the trapezoidal plug is separated from the annular hoop under the action of water.

[0017] Furthermore, the pile-net system includes a plurality of piles embedded below the ground surface and compacted soil laid on the piles. The compacted soil is also laid with a self-healing geotextile. The self-healing geotextile is a self-healing material for aquatic environments. Specifically, it may be a high-hardness elastomer for underwater rapid repair or other materials capable of self-healing in aquatic environments disclosed by Wang Chao's research group of Tsinghua University in Advanced Functional Materials under the title "AStiff yet Rapidly Self-Healable Elastomer in Harsh Aqueous Environments".

[0018] The beneficial effects of the present invention are as follows: the present invention realizes the suppression of the pot lid effect from multiple aspects, such as accelerating the migration of capillary water, centralized water transport and drainage, and inhibiting water freezing, and effectively utilizes the water generated by the pot lid effect with the help of self-repairing geotextiles, further improving the bearing capacity of the embankment and weakening the influence of the pot lid effect. Specifically, compared with the traditional pot lid effect suppression structure, the present invention, by setting a pressure-drawing system and a water-enriching system, fully utilizes the pressure difference formed by the change of air velocity when a train or a car passes by, accelerates the migration rate of capillary water in the soil, and realizes the local enrichment of the water body generated by the pot lid effect. At the same time, by utilizing the characteristics of the capsule phase change material that absorbs heat at high temperature and releases heat at low temperature, the solidification of water in the sand layer under low temperature environment is delayed, the freezing time is shortened and the freezing range is reduced, the influence of the suction effect is weakened, and the suppression of the pot lid effect is realized; by using the change of the center of gravity of the self-weight sealing plug and the water pressure effect, the self-drainage of the enriched water in the sand layer is realized under the premise of ensuring that a pressure difference environment can be effectively formed, so as to avoid the sand layer being in a saturated state for a long time. In addition, by introducing self-repairing geotextiles, with the help of the high humidity environment formed by the sand layer after water enrichment, the self-healing property of the water environment is fully utilized, the influence of the cracking of the geotextile on the soil arch effect and the film tension effect is weakened, and the problem of uneven settlement of the pile-supported reinforced embankment under the pot cover effect is solved, and the operation stability of the embankment is improved. In summary, the present invention uses a low-complexity structure to achieve the self-circulation operation of the overall system, improves the reliability of the overall system, ensures that the embankment is in a low moisture content state for a long time and has no long-term water enrichment area, and effectively suppresses the pot cover effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the frost damage prevention and control structure of pile-supported embankment in seasonally frozen areas;

[0020] Figure 2 It is a schematic diagram of the structure of the rich water drainage pipe and the pressure drainage pipe;

[0021] Figure 3 Schematic diagrams of different states of a self-weight sealing plug of a water-rich drainage pipe, wherein A is a schematic diagram of a closed state of the self-weight sealing plug, and B is a schematic diagram of an open state of the self-weight sealing plug;

[0022] Figure 4 Schematic diagrams of different states of the sealing assembly of the pressure drainage pipe, wherein A is a schematic diagram of the sealing assembly in a closed state, and B is a schematic diagram of the sealing assembly in an open state;

[0023] The marks in the attached drawings are: 1. pile-net system; 11. pile; 12. compacted soil; 13. self-repairing geotextile; 2. water-enriched system; 21. sand layer; 22. water-enriched drainage pipe; 221. water-enriched drainage pipe body; 222. self-weight sealing plug; 2221. connecting shaft; 223. sand-blocking net; 23. barrier layer; 3. pressure-guiding system; 31. pressure-guiding cavity; 311. lower shell surface of cavity; 312. upper shell surface of cavity; 32. pressure-guiding pipe; 33. pressure-guiding drainage pipe; 331. pressure-guiding drainage pipe body; 332 sealing assembly; 3321. annular hoop; 3322. trapezoidal plug; 3323. rebound strip; 4. roadbed base. DETAILED DESCRIPTION

[0024] The specific implementation of the present invention is described below with reference to the accompanying drawings.

[0025] like Figure 1 As shown, the present invention provides a pile-supported embankment frost damage prevention and control structure in seasonally frozen areas, comprising a pile network system 1, a water-enriched system 2, a pressure-drawing system 3 and a roadbed subgrade 4.

[0026] The pile-net system 1 is a support structure fixed to the ground surface, that is, a support force transmission structure embedded in the soil below the ground surface and partially exposed to the ground surface. The water-enriched system 2 includes a sand layer 21 and a water-enriched drainage pipe 22. The sand layer 21 is laid on the pile-net system 1. One end of the water-enriched drainage pipe 22 is arranged at the bottom of the sand layer 21, and the other end is communicated with the outside world, which can discharge the water in the sand layer 21 from the inside to the outside in one direction. The pressure-drawing system 3 includes a pressure-drawing chamber 31 and a pressure-drawing pipe 32. The pressure-drawing chamber 31 is arranged on the sand layer 21, and the bottom is water-proof and breathable, that is, only one-way gas circulation occurs between the pressure-drawing system 3 and the water-enriched system 2. The roadbed base 4 is laid on the pressure-drawing chamber 31. The pressure-drawing pipe 32 passes through the roadbed base 4, the lower end is communicated with the pressure-drawing chamber 31, and the upper end is arranged on the road surface at the top of the roadbed base 4, and communicates with the outside world.

[0027] The pressure chamber 31 uses the change in air velocity caused by vehicles passing on the road surface to form a pressure difference, so that the water in the pile-net system 1 and below is enriched in the sand layer 21; after the pressure difference disappears, the enriched water is discharged through the water-enriched drainage pipe 22, that is, the excellent drainage performance of sand and the deadweight of water are used to achieve the self-drainage effect of the sand layer 21. This process ensures that the embankment soil is in a low moisture content state for a long time, weakening or even avoiding the occurrence of the pot cover effect.

[0028] Regarding the pile-net system 1, Figure 1 As shown, in a preferred embodiment, the pile-net system 1 includes a plurality of piles 11 embedded below the ground surface and compacted soil 12 laid on the piles 11 , the compacted soil 12 is also laid with a self-repairing geotextile 13 , and a sand layer 21 is laid on the self-repairing geotextile 13 .

[0029] The pile 11 adopts a CFG pile or prefabricated pile with a pile cap, and the distance between the piles is 4 to 5 times the pile diameter. The self-repairing geotextile 13 is a self-healing material for water environment, and specifically can be a high-hardness elastomer or other material that can self-heal in water environment that is rapidly repaired underwater, which was published by Wang Chao's research group of Tsinghua University in Advanced Functional Materials as "AStiff yet Rapidly Self-Healable Elastomer in Harsh Aqueous Environments". The self-healing material for water environment uses the molecular structure that can undergo reversible chemical reactions inside the material to achieve the self-repair process in a high humidity environment. Compared with traditional geotextiles, the self-repairing geotextile 13 also has good water permeability, and the mechanical properties such as tensile strength and tear strength are similar. Under the premise of ensuring the existing soil arch effect and film pulling effect, the service life of the geotextile is extended, the long-term stability of the strength of the geotextile is guaranteed, and the weakening of the soil arch effect and film pulling effect caused by the tearing of the geotextile under differential settlement is avoided to a great extent, and the structural stability of the pile-supported reinforced embankment is guaranteed. At the same time, the moisture generated by the pot-lid effect is effectively utilized, which reduces the influence of the pot-lid effect on the pile-supported reinforced embankment to a certain extent.

[0030] Regarding the water-enriching system 2, in a preferred embodiment, the sand layer 21 is a phase-change sand layer, which is composed of uniformly mixed capsule phase-change materials and sand. The capsule phase-change material is in powder form under normal conditions, and in the mixed phase-change sand layer, the capsule phase-change material is evenly distributed in the sand. With the characteristics of the capsule phase-change material absorbing heat in a high-temperature environment and releasing heat in a low-temperature environment, the freezing phenomenon of the sand layer 21 after water enrichment in a low-temperature environment is effectively suppressed, the suction effect generated after the water body condenses and freezes is weakened, and the intensification of the pot cover effect is avoided.

[0031] like Figure 1 As shown, the water-enriched system 2 also includes a barrier layer 23. The barrier layer 23 is made of air-proof and water-proof materials, and is laid on the sand layer 21 and the outer side of the pile-net system 1 above the surface, so as to achieve seamless coverage of the slope surface from the lower shell surface of the pressure-inducing chamber 31 to the surface area. The barrier layer 23 is made of a polymer material with excellent air-proof and water-proof properties, which can block external water bodies and form a closed space at the same time, further ensuring the migration of capillary water under the action of pressure difference.

[0032] like Figure 2As shown, in a specific embodiment, the water-rich drainage pipe 22 includes a water-rich drainage pipe body 221, a self-weight sealing plug 222 and a sand-blocking net 223. The water-rich drainage pipe body 221 passes through the self-repairing geotextile 13 and the compacted soil 12 of the pile-net system 1, with the upper end arranged at the bottom of the sand layer 21 and the lower end arranged at the side of the compacted soil 12. The self-weight sealing plug 222 is arranged at the lower end of the water-rich drainage pipe body 221, and is rotatably connected to the upper side of the lower end of the water-rich drainage pipe body 221, and is covered outside the end of the water-rich drainage pipe body 221 by its own weight. Specifically, as Figure 3 As shown, the self-weight sealing plug 222 is made of high-strength rubber material such as hydrogenated nitrile rubber, and has a cone-like structure with an obtuse triangle cross-section. The short side is attached to the upper side of the pipe wall, and the tip is rotatably connected to the pipe wall through a connecting shaft 2221. When a pressure difference is formed in the pressure-drawing chamber 31, the water-rich drainage pipe body 221 is sealed by the self-weight sealing plug 222; after the pressure difference disappears, the self-weight sealing plug 222 opens under the action of water. That is, when the pressure-drawing system 3 works to form a negative pressure environment, the self-weight sealing plug 222 is in a closed state under the action of its own weight, which prevents the influx of external air from destroying the negative pressure environment. At this time, the water body is enriched from the bottom to the sand layer 21; when the pressure-drawing system 3 stops working, the self-weight sealing plug 222 in the closed state rotates along the connecting shaft 2221 under the action of water pressure, and changes from a closed state to an open state, and the water body previously enriched in the sand layer 21 flows outward, realizing the water body drainage function. The sand blocking net 223 is fixed on the upper end of the water-rich drainage pipe body 221 and is a thin sheet-shaped mesh structure, which is in direct contact with the sand layer 21 and blocks the sand layer 21 from being discharged outward with water.

[0033] The water-enriched system 2 uses the bottom of the pressure chamber 31 in the pressure-inducing system 3 to block the water body, realize the enrichment of the water body in the sand layer 21, and realizes the drainage of the water body enriched in the sand layer 21 through the one-way drainage water-enriched drainage pipe 22, and uses the sand-blocking net 223 to constrain the soil of the sand layer 21, avoiding the occurrence of soil erosion. The barrier layer 23 is used to block and protect the sand layer 21 and the structure below it, blocking the external water body while forming a closed space, ensuring the migration of capillary water under the action of pressure difference. Specifically, the sand layer 21 makes full use of the excellent water storage capacity and drainage performance of the sand, and uses the heat absorption and release efficiency of the capsule phase change material in the different environment to delay the solidification process of liquid water while realizing the capillary water enrichment process, shortening the duration of the suction effect. At the same time, the uniform mixing of sand and capsule phase change material ensures the uniformity of the delayed solidification effect of the capsule phase change material on the water body in the sand layer 21, and further weakens the pot cover effect. The water-rich drainage pipe 22 is arranged under the sand layer 21. Under the action of gravity, the water pressure at the bottom of the sand layer 21 rises after water is collected, forming an air pressure difference with the external atmospheric pressure, thereby realizing self-drainage of water without the help of other external forces. The sand-blocking net 223 constrains the sand layer 21 with the help of a fine grid, and exerts the bite effect of the sand layer 21 itself, ensuring that when the water in the sand layer 21 is discharged, the soil therein remains in a stable state, and the simultaneous discharge of water and soil is prevented. The self-weight sealing plug 222 is freely rotated within the constraint range through the connecting shaft 2221, and the automatic switching of the one-way drainage opening and closing state is realized by using the change of the center of gravity of the structure itself and the water pressure. While ensuring the water drainage function in the sand layer 21, the occurrence of air leakage during the formation of the pressure difference is avoided, and the pressure-drawing system 3 and the water-rich system 2 are mutually non-interfering, ensuring the effective operation of the functions of each system. By arranging the barrier layer 23 on both sides of the structure, effective isolation of external precipitation is achieved, the water supply to the pot cover effect is reduced to a certain extent, the formation of a negative pressure environment under the action of pressure difference is achieved, and the effect of accelerated migration of capillary water is ensured.

[0034] Regarding the pressure-inducing system 3 , the number of the pressure-inducing chambers 31 is one or a plurality of mutually independent ones, which is related to the type of the road surface on the top of the roadbed 4 .

[0035] If the road surface on top of the roadbed 4 is paved with railway tracks (railway tracks are track structures composed of a ballast and two steel rails, which belong to the prior art and will not be described in detail), the number of pressure chambers 31 is equal to and corresponds to the number of railway tracks, and the upper end of the pressure pipe 32 of the pressure chamber 31 is arranged between the double rails of the corresponding railway track, that is, the pressure difference is formed by the change in air flow rate caused by the running of the train. The upper end of the pressure pipe 32 protrudes from the road surface, that is, the surface of the ballast, and is lower than the top surface of the steel rail of the railway track. The structural form protruding from the surface of the ballast is conducive to the generation of vortex phenomenon, and according to the Coanda effect, a negative pressure domain can be generated locally in the surrounding environment, further enhancing the upward suction formed.

[0036] If the road surface on top of the roadbed subgrade 4 is a highway, the number of the pressure chambers 31 is equal to the number of lanes of the highway and corresponds one to one. The upper end of the pressure pipe 32 of the pressure chamber 31 is arranged in the middle of the corresponding lane, that is, the pressure difference is formed by the change in air flow rate caused by the driving of the vehicle.

[0037] like Figure 1 As shown, in this embodiment, two railway tracks are laid on the road surface on top of the roadbed subgrade 4 , so the pressure-inducing system 3 is provided with two pressure-inducing chambers 31 .

[0038] like Figure 1 As shown, in a preferred embodiment, each pressure chamber 31 is equipped with a pressure drainage pipe 33. One end of the pressure drainage pipe 33 is arranged at the bottom of the pressure chamber 31, and the other end is connected to the outside, so that rainwater and other accumulated water entering the pressure chamber 31 from the pressure pipe 32 can be discharged from the inside to the outside in a one-way manner.

[0039] The upper and lower ends of the pressure-inducing pipe 32 are both bell-mouthed, and the lower end is seamlessly connected to the pressure-inducing chamber 31. The bell-mouth arrangement increases the rate of gas passing through, provides greater upward suction for the migration of water vapor and capillary water, and further promotes the enrichment of moisture.

[0040] The pressure chamber 31 is formed by the lower shell surface 311 and the upper shell surface 312. The lower shell surface 311 is composed of a hollow rigid support and a waterproof breathable membrane covering it. The rigid support is made of high-strength metal material and is woven in a grid structure. The main material of the waterproof breathable membrane is EPTFE polytetrafluoroethylene, which selectively allows gas molecules to pass through and prevents the penetration of liquid molecules through a microporous structure or chemical treatment, thereby realizing the gas-liquid separation and migration under a pressure difference environment. The lower shell surface 311 of the chamber is a curved surface. The pressure drainage pipe 33 is connected to the lowest point of the lower shell surface 311 of the chamber, so that the accumulated water can be discharged smoothly. The curved lower shell surface 311 of the chamber is not only convenient for drainage, but also increases the contact area between the pressure chamber 31 and the sand layer 21, thereby improving the enrichment effect of the water body. The upper shell surface 312 of the chamber is in the shape of a trumpet with a wide mouth facing downward. The lower end of the pressure pipe 32 is connected to the top of the upper shell surface 312 of the chamber. The upper shell surface 312 of the cavity is made of rigid metal material, which can effectively block and drain rainwater while ensuring the strength of the structure itself, preventing rainwater from continuing to seep along the roadbed subgrade 4, thereby weakening the pot cover effect.

[0041] like Figure 1 As shown, in this embodiment, the two pressure-inducing chambers 31 share the same chamber lower shell surface 311 and chamber upper shell surface 312 , and the chamber upper shell surface 312 is separated into two independent pressure-inducing chambers 31 by a concave portion.

[0042] like Figure 2As shown in FIG. 1 , in a specific embodiment, the pressure drainage pipe 33 includes a pressure drainage pipe body 331 and a sealing assembly 332. The pressure drainage pipe body 331 passes through the sand layer 21, with the upper end arranged at the bottom of the pressure chamber 31 and the lower end arranged at the side of the sand layer 21. Figure 4 As shown, the sealing assembly 332 includes an annular hoop 3321, a trapezoidal plug 3322 and a plurality of rebound strips 3323. The pressure-drawing drainage pipe body 331 includes a vertical section and an inclined section. The annular hoop 3321 is fixed in the vertical section of the pressure-drawing drainage pipe body 331, and the inner diameter gradually increases from top to bottom. The trapezoidal plug 3322 is arranged in the annular hoop 3321. The rebound strip 3323 is V-shaped, passes through the trapezoidal plug 3322, and is fixed to the annular hoop 3321 at both ends. The inner diameter of the lower end of the annular hoop 3321 is equal to the outer diameter of the lower end of the trapezoidal plug 3322, and the inner diameter of the upper end is smaller than the outer diameter of the upper end of the trapezoidal plug 3322. When a pressure difference is formed in the pressure-drawing chamber 31, the annular hoop 3321 is sealed by the trapezoidal plug 3322 under the tensile force of the rebound strip 3323; after the pressure difference disappears, the trapezoidal plug 3322 is separated from the annular hoop 3321 under the action of water. That is, when the pressure-guiding system 3 is working to form a negative pressure environment, under the tensile force of the rebound strip 3323, when the pressure-guiding drainage pipe body 331 is in a closed state, the rebound strip 3323 is in a state of secondary strong stress, and the annular hoop 3321 is tightly connected to the lower part of the inverted ladder plug, which limits the outflow of water and prevents the influx of outside air from destroying the negative pressure environment; when the pressure-guiding system 3 stops working, under the action of the deadweight of the water body, the pressure-guiding drainage pipe 33 is in an open state, the rebound strip 3323 is in a state of strong stress, and the annular hoop 3321 is completely separated from the inverted ladder plug structure without any contact, which reserves a passage for the water exchange process and effectively realizes the outward drainage of the water body. The sealing component 332 of the pressure-guiding drainage pipe 33 adopts a non-completely fitting structure, and the separation of the trapezoidal plug 3322 and the annular hoop 3321 is achieved through the pressure difference, and the elasticity of the rebound strip 3323 itself is used to achieve the reset of the trapezoidal plug 3322 after the internal and external pressure difference is balanced. The triangular gap formed by the size difference between the annular hoop 3321 and the trapezoidal plug 3322 realizes effective water exchange when the trapezoidal plug 3322 is separated from the annular hoop 3321. The rebound strips 3323 with different rebound capabilities and initial deformation tensile forces can be selected according to the actual stress state. The connection between the rebound strip 3323 and the annular hoop 3321 and the trapezoidal plug 3322 reserves a passage for the water exchange process, and the V-shaped arrangement of the rebound strip 3323 realizes a smooth transition of the rebound strip 3323 under different stress states.

[0043] The pressure-inducing system 3 is based on the Bernoulli principle and the Coanda effect, and utilizes the difference in air flow rate between the bottom of a high-speed train, a freight train or a car on a highway and the road surface to generate a pressure difference, thereby forming an upward suction force. At the same time, under the action of a waterproof and breathable membrane, the pressure-inducing system 3 accelerates the migration of water vapor and capillary water in the compacted soil 12 and the soil below it without relying on other external energy sources. By setting a pressure-inducing drainage pipe 33, the occurrence of water accumulation in the pressure-inducing chamber 31 is avoided, thereby ensuring the effective operation of the pressure-inducing system 3.

[0044] The roadbed base 4 is mainly filled with graded crushed stone or graded gravel, etc., and the filling height is not less than 0.7m.

[0045] The construction method of the pile-supported embankment frost damage prevention and control structure in seasonally frozen areas of the present invention comprises the following steps:

[0046] S1. Arrange the piles according to the designed marked positions, lay the compacted soil according to the preset height and arrange the water-rich drainage pipes, and lay multiple layers of self-repairing geotextiles on the compacted soil.

[0047] S2. After the sand and capsule phase change material are fully mixed, they are laid on the self-repairing geotextile. The density of the sand layer is controlled and laid out in multiple times. The initial layout height is controlled at 1 / 4 to 1 / 3 of the design height. While laying the sand layer, the pressure drainage pipe is laid out.

[0048] S3. A barrier layer is fitted along the sand layer and the compacted earth slope, and outlets for water-rich drainage pipes and pressure drainage pipes are opened according to the design plan.

[0049] S4. A pressure-inducing system is laid on the sand layer, and the roadbed is constructed on the upper part of the pressure-inducing cavity according to the relevant requirements of the "Technical Specifications for Highway Roadbed Construction" or "Design Specifications for Railway Roadbed" according to the actual use environment.

[0050] In the present invention, unless otherwise specified, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. In addition, the materials and operating steps used herein are the materials and conventional steps widely used in the corresponding fields.

[0051] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0052] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pile-supported embankment frost damage prevention and control structure in seasonally frozen areas, characterized by: It comprises a pile network system (1), a water-enriching system (2), a pressure-inducing system (3) and a roadbed (4); The pile-net system (1) is a support structure fixed to the ground surface; The water-enriched system (2) comprises a sand layer (21) and a water-enriched drainage pipe (22); the sand layer (21) is laid on the pile-net system (1); one end of the water-enriched drainage pipe (22) is arranged at the bottom of the sand layer (21), and the other end is communicated with the outside, so that the water in the sand layer (21) can be discharged from the inside to the outside in a one-way manner; The pressure-inducing system (3) comprises a pressure-inducing chamber (31) and a pressure-inducing pipe (32); the pressure-inducing chamber (31) is arranged on the sand layer (21), and the bottom thereof is water-proof and air-permeable; the roadbed (4) is laid on the pressure-inducing chamber (31); the lower end of the pressure-inducing pipe (32) is connected to the pressure-inducing chamber (31), and the upper end thereof is arranged on the road surface on the top of the roadbed (4) and is in communication with the outside world; The pressure chamber (31) utilizes the change in air velocity caused by the vehicle passing on the road surface to form a pressure difference, so that the water in the pile-net system (1) and below it is enriched in the sand layer (21); After the pressure difference disappears, the enriched water is discharged through the enriched water drain pipe (22).

2. The pile-supported embankment frost damage prevention and control structure in seasonally frozen areas according to claim 1, characterized in that: The sand layer (21) is a phase change sand layer, which is composed of uniformly mixed capsule phase change material and sand.

3. The pile-supported embankment frost damage prevention and control structure in seasonally frozen areas according to claim 1 is characterized by: The water-rich system (2) further comprises a barrier layer (23); the barrier layer (23) is made of air-proof and water-proof material and is laid on the sand layer (21) and the outer side of the pile-net system (1) above the ground surface.

4. The pile-supported embankment frost damage prevention and control structure in seasonally frozen areas according to claim 1, characterized in that: The water-rich drainage pipe (22) comprises a water-rich drainage pipe body (221), a self-weight sealing plug (222) and a sand blocking net (223); The water-rich drainage pipe body (221) passes through the pile-net system (1), with the upper end arranged at the bottom of the sand layer (21) and the lower end arranged at the side of the pile-net system (1); The self-weight sealing plug (222) is arranged at the lower end of the water-rich drainage pipe body (221), is rotatably connected to the upper side of the lower end of the water-rich drainage pipe body (221), and covers the outside of the end of the water-rich drainage pipe body (221) by its own weight; when a pressure difference is formed in the pressure-inducing chamber (31), the water-rich drainage pipe body (221) is sealed by the self-weight sealing plug (222); when the pressure difference disappears, the self-weight sealing plug (222) is opened under the action of water; The sand blocking net (223) is fixed to the upper end of the water-rich drainage pipe body (221) to block the sand layer (21) from being discharged outward along with the water; Water-rich drainage pipes (22) are provided on both sides of the bottom of the sand layer (21).

5. The pile-supported embankment frost damage prevention and control structure in seasonally frozen areas according to claim 1, characterized in that: The number of the pressure-inducing chambers (31) is one or a plurality of mutually independent ones; The pressure-inducing chamber (31) is provided with a pressure-inducing drainage pipe (33); one end of the pressure-inducing drainage pipe (33) is arranged at the bottom of the pressure-inducing chamber (31), and the other end is communicated with the outside, so that the accumulated water in the pressure-inducing chamber (31) can be discharged from the inside to the outside in a one-way manner.

6. The pile-supported embankment frost damage prevention and control structure in seasonally frozen areas according to claim 5, characterized in that: The road surface on the top of the roadbed (4) is paved with railway tracks; The number of the pressure-inducing chambers (31) is equal to and corresponds to the number of railway tracks, and the upper ends of the pressure-inducing pipes (32) of the pressure-inducing chambers (31) are arranged between the double rails of the corresponding railway track; The upper end of the pressure-inducing pipe (32) protrudes above the road surface and is lower than the top surface of the railway track.

7. The pile-supported embankment frost damage prevention and control structure in seasonally frozen areas according to claim 5, characterized in that: The road surface on the top of the roadbed (4) is a highway; The number of the pressure-inducing chambers (31) is equal to and corresponds to the number of lanes of the expressway, and the upper ends of the pressure-inducing pipes (32) of the pressure-inducing chambers (31) are arranged in the middle of the corresponding lanes.

8. The pile-supported embankment frost damage prevention and control structure in seasonally frozen areas according to claim 5, characterized in that: The pressure-inducing chamber (31) is formed by enclosing a chamber lower shell surface (311) and a chamber upper shell surface (312); The lower shell surface (311) of the cavity is composed of a hollow rigid support and a waterproof and breathable membrane; The lower shell surface (311) of the cavity is a curved surface; the pressure-drawing and drainage pipe (33) is connected to the lowest point of the lower shell surface (311) of the cavity; The upper shell surface (312) of the cavity is in the shape of a trumpet with a wide mouth facing downward; the lower end of the pressure-guiding tube (32) is connected to the top end of the upper shell surface (312) of the cavity.

9. The pile-supported embankment frost damage prevention and control structure in seasonally frozen areas according to claim 5, characterized in that: The pressure-conducting drainage pipe (33) comprises a pressure-conducting drainage pipe body (331) and a sealing assembly (332); The pressure drainage pipe body (331) passes through the sand layer (21), with the upper end arranged at the bottom of the pressure chamber (31) and the lower end arranged on the side of the sand layer (21); The sealing assembly (332) comprises an annular hoop (3321), a trapezoidal plug (3322) and a plurality of resilient strips (3323); the annular hoop (3321) is fixed in the pressure drainage pipe body (331), and the inner diameter gradually increases from top to bottom; the trapezoidal plug (3322) is arranged in the annular hoop (3321); the resilient strip (3323) passes through the trapezoidal plug (3322), and the two ends are fixed to the annular hoop (3321); The inner diameter of the lower end of the hoop (3321) is equal to the outer diameter of the lower end of the trapezoidal plug (3322), and the inner diameter of the upper end is smaller than the outer diameter of the upper end of the trapezoidal plug (3322); when a pressure difference is formed in the pressure-inducing chamber (31), the annular hoop (3321) is sealed by the trapezoidal plug (3322) under the tensile force of the rebound strip (3323); after the pressure difference disappears, the trapezoidal plug (3322) is separated from the annular hoop (3321) under the action of water.

10. The pile-supported embankment frost damage prevention and control structure in seasonally frozen areas according to claim 1, characterized in that: The pile-net system (1) comprises a plurality of piles (11) embedded below the ground surface and compacted soil (12) laid on the piles (11); the compacted soil (12) is also laid with a self-repairing geotextile (13); the self-repairing geotextile (13) is a water environment self-healing material.

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