Method for inhibiting freezing and thawing damage of slope in seasonal frozen area by using foam fluid

Abstract

The invention provides a method for inhibiting freezing and thawing damage of a slope in a seasonal frozen area through foam fluid, and belongs to the technical field of slope reinforcement and protection.The method comprises the steps that the foam fluid is guided into the slope in the seasonal frozen area through a guiding-in device, and the guiding-in device comprises a liquid homogenizing system and a foam fluid storage mechanism; the liquid homogenizing system is arranged between an outer covering layer and a cushion layer of the side slope and comprises a liquid dispersing floral tube, the liquid dispersing floral tube comprises a plurality of liquid spraying tubes, and a plurality of slurry spraying structures are arranged on the sides, facing the cushion layer, of the liquid spraying tubes. The liquid spraying pipe communicates with the foam fluid storage mechanism, and foam fluid in the foam fluid storage mechanism escapes to the cushion layer through the slurry spraying structure after entering the liquid spraying pipe. According to the method, foam fluid escapes into the cushion layer, a foam fluid area is formed in the cushion layer, the fluid resistance required for passing through holes of the cushion layer is increased, and water infiltration is inhibited, so that the water content of a soil body is reduced, frost heaving damage is inhibited, and freeze-thaw damage of the slope in the seasonal frozen area is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of slope reinforcement and protection, and relates to a method for suppressing freeze-thaw damage of slopes in seasonally frozen areas using a foam fluid. Background Art

[0002] Freeze-thaw damage is one of the main diseases faced by slope engineering in seasonally frozen areas, and often occurs in water-rich areas such as channel slopes. Under the action of repeated freeze-thaw, water-induced landslides and frost heave and thaw settlement become more and more obvious, causing irreversible damage to shallow soil, causing damage to structures such as water delivery channels, aggravating water leakage, and forming a vicious cycle in the long run. At the same time, in the current construction and development of seasonally frozen area projects, freeze-thaw damage has become the main cause of slope instability and landslides in seasonally frozen areas. Therefore, a structure and method for inhibiting freeze-thaw damage to slopes in seasonally frozen areas are proposed, which has great practical engineering significance.

[0003] The existing technical methods for inhibiting freeze-thaw damage of slopes in seasonally frozen areas are mostly optimized from the aspects of controlling the temperature of the concrete-soil interface and enhancing the ductility of the structure. The patent with the patent publication number CN113295563A introduces a method for treating the expansion problem of channels based on phase change materials. Its fundamental principle is to actively regulate the temperature field inside the channel through the phase change energy storage effect of the phase change material to inhibit the occurrence of freezing. However, this method has the problem of excessive waste and cannot be adjusted according to the actual frost heave situation. Flexible fabrics, as a common geotechnical material, have a good inhibitory effect on frost heave and thaw settlement. The patent with the patent publication number CN113605318A proposes a flexible anti-erosion columnar channel protection facility and its construction method, which uses the flexibility and ductility of geotextiles to inhibit the occurrence of channel frost heave. However, this method is difficult to continue to effectively inhibit the frost heave phenomenon after the structure is frozen and thawed. Therefore, it is of practical significance to propose a structure with long-term frost heave inhibition ability and adjustable inhibition according to the actual frost heave situation.

[0004] Foam fluid is a dispersed system formed by gas dispersed in liquid in the form of bubbles, in which liquid is the continuous phase and gas is the dispersed phase. It has excellent "blocking" performance. Currently, there is no report on the application of foam fluid in inhibiting freeze-thaw damage to slopes in seasonally frozen areas. Therefore, giving full play to the "blocking" performance of foam fluid to achieve real-time regulation and inhibition of freeze-thaw damage to slopes in seasonally frozen areas has extremely strong engineering application value. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid. The method utilizes the Jamin effect produced by bubbles passing through pore throats smaller than their own radius when the foam fluid flows in a porous medium, thereby greatly improving the fluid resistance in the porous medium, thereby suppressing the infiltration process of water bodies, directly or indirectly reducing the moisture content of the soil, and reducing the adverse effects of freeze-thaw damage on the slopes.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluids. The method comprises the following steps: introducing foam fluids into the slopes in the seasonally frozen areas, wherein the foam fluids generate a resistance effect in the soil of the slopes in the seasonally frozen areas, suppress water infiltration, reduce the water content of the soil, and suppress freeze-thaw damage of the slopes in the seasonally frozen areas.

[0008] Furthermore, the seasonally frozen area slope includes a slope, an outer covering layer and a cushion layer, and the cushion layer and the outer covering layer are distributed outside the slope in sequence from the inside to the outside; the foam fluid is introduced into the cushion layer through an introduction device, and the introduction device includes a liquid uniformity system and a foam fluid storage mechanism, and the liquid uniformity system is arranged between the outer covering layer and the cushion layer; the liquid uniformity system includes a scattered liquid flower tube, and the scattered liquid flower tube includes a plurality of groups of liquid spraying pipes, and a plurality of groups of spraying structures are arranged on the side of the liquid spraying pipe facing the cushion layer; the liquid spraying pipe is connected to the foam fluid storage mechanism, and after the foam fluid inside the foam fluid storage mechanism enters the liquid spraying pipe, it escapes to the cushion layer through the spraying structure.

[0009] Furthermore, the liquid homogenizing system also includes an excitation domain; the excitation domain includes an excitation pipe arranged between the outer covering layer and the cushion layer, the excitation pipe is connected to the foam fluid storage mechanism on the one hand, and is connected to the spray pipe on the other hand, and the foam fluid inside the foam fluid storage mechanism enters the spray pipe through the excitation pipe; the excitation pipe can be deformed under the action of water pressure or frost heave force, so as to prompt the foam fluid in the excitation pipe to migrate to the spray pipe and dissipate outward through the spraying structure.

[0010] Furthermore, the excitation pipes include several groups of internal pressure excitation pipes and several groups of external pressure excitation pipes; the internal pressure excitation pipes are distributed in the outer covering layer; the several groups of internal pressure excitation pipes are interconnected through a first grouting pipe, and the first grouting pipe is connected to a foam fluid storage mechanism; the external pressure excitation pipes are distributed in the cushion layer; the several groups of external pressure excitation pipes are interconnected through a second grouting pipe, and the second grouting pipe is connected to a foam fluid storage mechanism.

[0011] Furthermore, the several groups of liquid spraying pipes are equidistantly arranged and distributed vertically along the slope; the several groups of internal pressure excitation pipes are equidistantly arranged, and the internal pressure excitation pipes and the liquid spraying pipes are perpendicular to each other, and the first grouting pipe is parallel to the liquid spraying pipe; the several groups of external pressure excitation pipes are equidistantly arranged, and the external pressure excitation pipes and the liquid spraying pipes are perpendicular to each other, and the second grouting pipe is parallel to the liquid spraying pipe.

[0012] Furthermore, a slurry outlet is provided on the wall of the liquid spraying pipe, and the liquid spraying pipe is connected with the excitation pipe through the slurry outlet.

[0013] Furthermore, the cross-section of the internal pressure excitation pipe is circular, the cross-section of the external pressure excitation pipe is a narrow rectangle / ellipse / rounded rectangle, and the contact area between the external pressure excitation pipe and the cushion layer is greater than the contact area between the internal pressure excitation pipe and the outer covering layer.

[0014] Furthermore, the foam fluid storage mechanism includes a slurry storage chamber and a cover plate; the cover plate is installed on the slurry storage chamber, and a one-way exhaust valve is provided on the cover plate.

[0015] Furthermore, the cushion layer is made of sand and / or gravel, and geotextiles are evenly distributed in the cushion layer.

[0016] Furthermore, among the several groups of spraying structures, each group of spraying structures includes two spraying ports and two nozzles; the two spraying ports are opened on the spraying pipe, and the angle between the axes of the two spraying ports is 120°; the nozzle is a conical lampshade structure with openings at both ends, and the side with the larger opening of the conical lampshade structure is fixed at the spraying port and is connected to the spraying pipe through the spraying port.

[0017] Furthermore, the method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by foam fluid specifically comprises the following steps:

[0018] Step 1: Lay a cushion layer along the slope surface. The cushion layer includes 1 to 3 sandy soil layers. After each layer of sandy soil is laid, it is compacted and covered with geotextiles.

[0019] Step 2: connect each group of internal pressure excitation pipes through the first grouting pipe, connect each group of external pressure excitation pipes through the second grouting pipe, and connect the internal pressure excitation pipe and the external pressure excitation pipe to the liquid spraying pipe. After the arrangement is completed, pour concrete to form a prefabricated structure of the outer covering layer-liquid distribution system;

[0020] Step 3: Lay the outer cover-liquid distribution system prefabricated structure on the cushion layer;

[0021] Step 4: placing a foam fluid storage mechanism on the upper part of the slope, and connecting the first grouting pipe and the second grouting pipe to the foam fluid storage mechanism;

[0022] Step 5: slowly fill the foam fluid into the foam fluid storage mechanism in batches, observe that the foam fluid liquid level in the foam fluid storage mechanism remains constant within a certain period of time, and there is no liquid leakage at the connection of the prefabricated mechanism, then the structure assembly is qualified;

[0023] Step six, connect the cover plate provided with a one-way exhaust valve to the foam fluid storage mechanism, and the structural assembly is completed. When the channel water conveyance generates water pressure on the slope, or the slope generates frost heave force when it frosts, the exciting pipe undergoes elastic deformation under the action of the water pressure or frost heave force, prompting the foam fluid in the exciting pipe to migrate to the spray pipe and escape outward through the spraying structure.

[0024] The beneficial effects of the present invention are:

[0025] (1) The present invention is provided with a dispersed liquid flower pipe composed of a plurality of liquid spraying pipes, and the liquid spraying pipe is connected with a foam fluid storage mechanism. The foam fluid inside the foam fluid storage mechanism can enter the liquid spraying pipe and escape to the cushion layer through the spraying structure opened on the liquid spraying pipe wall. The foam fluid forms a foam fluid area in the cushion layer, which can block the pores of the cushion layer, thereby realizing water body isolation. By reducing the water content of the soil, the frost heave damage is suppressed, and the freeze-thaw damage of the slope in the seasonally frozen area is avoided.

[0026] (2) The present invention also provides an excitation domain for regulating the state of foam fluid dispersion. The excitation domain is an excitation pipe that can be deformed. The excitation pipe can be deformed under the action of water pressure or frost heave force, so as to promote the foam fluid in the excitation pipe to migrate to the spray pipe and disperse outward through the spraying structure. The present invention, through the setting of the excitation pipe, combines the actual application scenario, effectively utilizes the water pressure and frost heave force that often appear in the freeze-thaw damage environment of the slope, changes the internal pressure of the bulk flower pipe through external pressure changes, controls the dispersion state of the foam fluid, changes the influence range and barrier effect of the foam fluid, establishes a proportional relationship between the blocking effect and the water pressure and frost heave force, and innovatively realizes that the ability to block water infiltration is enhanced with the increase of water pressure and frost heave force, thereby weakening the freeze-thaw damage phenomenon of the slope in the seasonally frozen area.

[0027] (3) In the present invention, foam fluid is supplied to the internal pressure excitation pipe and the external pressure excitation pipe through the foam fluid storage mechanism and the slurry supply pipe, and sufficient foam fluid is provided to the bulk liquid flower pipe through the internal pressure excitation pipe and the external pressure excitation pipe distributed on both sides of the bulk liquid flower pipe, and the excitation pipe controls the escape rate and escape range of the foam fluid according to the change of external pressure.

[0028] (4) In the present invention, each group of spraying structures is provided with two spraying ports and two nozzles. The two nozzles are at the same height and have different spraying directions. The nozzles are conical lampshade structures with a large inside and a small outside, which effectively realizes the high-pressure escape of the foam fluid, expands the coverage range of the foam fluid, and ensures the sealing and barrier effect of the foam fluid action area in the cushion layer.

[0029] (5) In the present invention, the first grouting pipe and the second grouting pipe are independently connected to the internal pressure excitation pipe and the external pressure excitation pipe, and are arranged at fixed intervals. The arrangement form of dedicated pipes for dedicated areas is adopted, which ensures that there is sufficient foam fluid in each excitation pipe, solves the problem of uneven distribution of foam fluid caused by cross-mixing, indirectly improves the dispersion effect of the foam fluid, and ensures the coverage of the foam fluid.

[0030] (6) In the present invention, the sealing effect of the slurry storage chamber is achieved by a cover plate, and a one-way exhaust valve is provided on the cover plate, which can adjust the air pressure in the slurry storage chamber according to the requirements of different foam fluid injection and discharge stages, thereby avoiding the occurrence of foam fluid slurry return phenomenon, ensuring the dispersion effect of the foam fluid, and achieving high-quality suppression of freeze-thaw damage to the slope. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the connection relationship of the grouting cross-section structure of the foam fluid to inhibit the freeze-thaw damage structure of the slope in the seasonally frozen area; A is a schematic diagram of the grouting cross-section perpendicular to the slope structure, and B is a schematic diagram of the grouting cross-section parallel to the slope structure;

[0032] Figure 2 Schematic diagram of the connection relationship of the grouting cross-section structure of the structure of the seasonally frozen slope using foam fluid to suppress freeze-thaw damage; A is a schematic diagram of the grouting cross-section perpendicular to the slope structure, and B is a schematic diagram of the grouting cross-section parallel to the slope structure;

[0033] Figure 3 Schematic diagram of the structure and connection relationship of the liquid spray pipe; wherein A is a schematic diagram of the connection relationship between the liquid spray pipe and its surrounding structures, B is a schematic diagram of the structure of the liquid spray pipe itself, C is a schematic diagram of the vertical structure of the nozzle, and D is a schematic diagram of the top view of the nozzle structure;

[0034] Figure 4 Schematic diagram of the connection relationship between each excitation pipeline and its surrounding structure; A is a schematic diagram of the connection relationship between the end internal pressure excitation pipeline and its surrounding structure, B is a schematic diagram of the connection relationship between the external pressure excitation pipeline-slurry outlet and its surrounding structure, C is a schematic diagram of the connection relationship between the middle internal pressure excitation pipeline and its surrounding structure, and D is a schematic diagram of the connection relationship between the external pressure excitation pipeline and its surrounding structure;

[0035] Figure 5Schematic diagram of the process of reducing permeability and increasing resistance by foam fluid; wherein A is a schematic diagram of the bonding state of sand and its surrounding materials in a saturated state, and B is a schematic diagram of the bonding state of sand and its surrounding materials after the foam fluid is injected.

[0036] The symbols in the accompanying drawings are:

[0037] 1. Outer covering layer; 2. Liquid equalization system; 21. Liquid spraying pipe; 211. Pipe wall; 212. Shotcrete structure; 221. Internal pressure excitation pipe; 222. External pressure excitation pipe; 2231. First grouting pipe; 2232. Second grouting pipe; 23. Slurry outlet; 3. Cushion layer; 31. Geotextile; 4. Foam fluid storage mechanism; 41. Slurry storage chamber; 411. Cover plate; 5. Sand; 6. Water; 61. Liquid film; 7. Gas; 8. Slope. DETAILED DESCRIPTION

[0038] 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 combination with the embodiments of the present invention and the accompanying drawings. 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 making creative work are within the scope of protection of the present invention.

[0039] Example 1

[0040] An embodiment of the present invention provides a method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid. The method comprises the following steps: introducing foam fluid into the slopes in the seasonally frozen areas, wherein the foam fluid generates a resistance effect in the soil of the slopes in the seasonally frozen areas, suppresses water infiltration, reduces the moisture content of the soil, and suppresses freeze-thaw damage of the slopes in the seasonally frozen areas.

[0041] Specifically, Figures 1-2 As shown, the seasonally frozen area slope includes a slope 8, an outer covering layer 1 and a cushion layer 3. The cushion layer 3 is laid outside the soil of the slope 8. The material of the cushion layer 3 is sand and is laid in layers. Geotextiles 31 are evenly arranged between each cushion layer 3, and a structural layer with a certain thickness is formed after compaction. The outer covering layer 1 is located at the outermost part of the overall structure. The outer covering layer 1 is a fiber concrete structure. Compared with conventional concrete, the fiber concrete has better crack resistance after hardening, improves the ductility of the structure, can effectively reduce the number of cracks in the outer covering layer, and effectively reduces the amount of water infiltration.

[0042] Among them, the foam fluid is introduced into the cushion layer 3 through an introduction device, and the introduction device includes a liquid equalization system 2 and a foam fluid storage mechanism 4. The foam fluid storage mechanism 4 is provided with foam fluid, and the foam fluid is an existing material, and its preparation method has been disclosed in the prior art, so its preparation process is not described in detail here. The liquid equalization system 2 is arranged between the outer covering layer 1 and the cushion layer 3, including a scattered liquid flower tube, and the scattered liquid flower tube includes a plurality of groups of liquid spraying pipes 21, and a plurality of groups of spraying structures 212 are arranged on the side of the liquid spraying pipe 21 facing the cushion layer 3. The foam fluid storage mechanism 4 is directly or indirectly connected to the liquid spraying pipe 21, and the foam fluid inside the foam fluid storage mechanism 4 enters the liquid spraying pipe 21 and escapes to the cushion layer 3 through the spraying structure 212. In other embodiments of the present invention, a foam fluid flow regulating structure can also be provided to realize the control of the escape state of the foam fluid in the liquid spraying pipe 21.

[0043] In the present invention, the foam fluid dissipated in the cushion layer 3 forms a foam fluid area in the cushion layer 3. When the foam fluid flows in the porous cushion layer 3, since the radius of the bubble is greater than the radius of the pore throat, the bubble must be deformed to pass through the pore throat. At this time, the capillary resistance generated by the bubble deformation will produce a resistance effect (Jamien effect) at the pore throat, and the foam fluid retained in the pore is greatly increased due to the influence of the Jamin effect, achieving a "blocking" effect, and then forming a water barrier between the cushion layer 3 and the outer cover 1, thereby achieving regional moisture content control, inhibiting the occurrence of frost heave, and achieving the purpose of avoiding freeze-thaw damage.

[0044] Example 2

[0045] This embodiment provides a method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid, which is different from Embodiment 1 in that: in this embodiment, the liquid homogenizing system 2 also includes an excitation domain for adjusting the dispersion state of the foam fluid.

[0046] Specifically, Figures 1-2 As shown, the excitation domain includes an excitation pipe arranged between the outer cover 1 and the cushion layer 3. The excitation pipe is connected to the foam fluid storage mechanism 4 on the one hand, and is connected to the spray pipe 21 on the other hand (the pipe wall 211 of the spray pipe 21 is provided with a slurry outlet 23, and the spray pipe 21 is connected to the excitation pipe through the slurry outlet 23). The foam fluid inside the foam fluid storage mechanism 4 enters the spray pipe 21 through the excitation pipe. The excitation pipe is a pipe that can be deformed and has a certain strength. It can be deformed under the action of water pressure or frost heave force, thereby promoting the foam fluid in the excitation pipe to migrate to the spray pipe 21 and escape to the cushion layer 3 through the spraying structure 212. Among them, the excitation pipe can use plastic as a raw material, and specifically, plastic materials such as polyethylene terephthalate (PET), polyethylene (PE) and polypropylene (PP) can be selected.

[0047] Principle of this scheme: Since the channel will generate water pressure on the slope during the water delivery process, the slope will generate frost heave force when it frosts. The scheme of the present invention considers using the above-mentioned water pressure and frost heave force to control the process of foam fluid injection. When applied, the foam fluid in the foam fluid storage mechanism 4 flows into the excitation pipe and the scattered liquid flower tube, and the foam fluid is in a fully filled state in the excitation pipe and the scattered liquid flower tube. When water flows into the channel during the flood season and generates water pressure on the slope, or when the slope generates frost heave force, the excitation pipe deforms, prompting the foam fluid in the excitation domain to migrate to the scattered liquid flower tube, and escape outward through the spraying structure 212, forming a foam fluid area in the cushion layer 3, and forming a water barrier between the cushion layer 3 and the outer covering layer 1, so as to achieve regional moisture content control, avoid the occurrence of frost heave phenomenon, and suppress freeze-thaw damage phenomenon. When the water pressure and frost heave force disappear, the deformation of the excitation pipe disappears, and the escape effect of the foam fluid is reduced or disappears accordingly.

[0048] The technical solution of this embodiment is combined with the actual application scenario, and the water pressure and frost heaving force that often appear in the freeze-thaw damage environment of the slope are effectively utilized. The internal pressure of the equalizing liquid system is changed by changing the external pressure, the fluid foam escape state is controlled, the fluid foam influence range and the barrier effect are changed, and a proportional relationship between the blocking effect and the water pressure and frost heaving force is established. The innovative barrier effect of the foam fluid on the infiltration of water bodies is enhanced with the increase of water pressure and frost heaving force, thereby weakening the freeze-thaw damage phenomenon of the slopes in the seasonally frozen area.

[0049] Example 3

[0050] This embodiment provides a method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid. The difference from Embodiment 2 is that this embodiment further limits the excitation pipeline.

[0051] Specifically, refer to Figures 1-2 and Figure 4 The excitation pipeline includes several groups of internal pressure excitation pipelines 221 and several groups of external pressure excitation pipelines 222, and each group of internal pressure excitation pipelines 221 is connected to each spray pipe 21 respectively, and each group of external pressure excitation pipelines 222 is connected to each spray pipe 21 respectively.

[0052] The internal pressure excitation pipe 221 is embedded in the outer cover 1, and several groups of internal pressure excitation pipes 221 are interconnected through the first grouting pipe 2231, and the near-ground port of the first grouting pipe 2231 is connected to the foam fluid storage mechanism 4. In other embodiments of the present invention, it can also be configured as follows: the internal pressure excitation pipe 221 distributed on the top is directly connected to the foam fluid storage mechanism 4, and each group of internal pressure excitation pipes 221 is interconnected through the first grouting pipe 2231.

[0053] The external pressure excitation pipe 222 is arranged in the cushion layer 3 , and several groups of the external pressure excitation pipes 222 are interconnected through the second grouting pipe 2232 , and the near-ground port of the second grouting pipe 2232 is connected to the foam fluid storage mechanism 4 .

[0054] In this embodiment, the first grouting pipe 2231 and the second grouting pipe 2232 are independently connected to the internal pressure excitation pipe 221 and the external pressure excitation pipe 222, respectively, ensuring that there is sufficient foam fluid in each excitation pipe, solving the problem of uneven distribution of foam fluid caused by cross-mixing, and indirectly improving the dispersion effect of the foam fluid, ensuring the coverage range of the foam fluid.

[0055] Example 4

[0056] This embodiment provides a method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid. The difference from Embodiment 3 is that this embodiment further limits the arrangement of the liquid spray pipe 21, the internal pressure excitation pipe 221 and the external pressure excitation pipe 222.

[0057] Specifically, refer to Figures 1-2 , several groups of liquid spraying pipes 21 are arranged at equal distances and are vertically distributed along the slope 8. Several groups of internal pressure excitation pipes 221 are arranged at equal distances, and the internal pressure excitation pipes 221 and the liquid spraying pipes 21 are perpendicular to each other, and the first grouting pipe 2231 is parallel to the liquid spraying pipe 21. The liquid spraying pipe 21 is connected to the internal pressure excitation pipe 221 at multiple points through the slurry outlet 23. Several groups of external pressure excitation pipes 222 are arranged at equal distances, and the external pressure excitation pipes 222 and the liquid spraying pipes 21 are perpendicular to each other, and the second grouting pipe 2232 is parallel to the liquid spraying pipe 21. The liquid spraying pipe 21 is connected to the external pressure excitation pipe 222 at multiple points through the slurry outlet 23.

[0058] In addition, the cross-section of the internal pressure excitation pipe 221 is circular, and the cross-section of the external pressure excitation pipe 222 is a narrow and long rectangle / ellipse / rounded rectangle.

[0059] The above design forms an integrated grid structure of "internal pressure excitation domain-bulk liquid flower tube-external pressure excitation domain" in the upper, middle and lower layers, which ensures the coverage area of ​​the foam fluid while taking into account the coordination of spraying, realizes the sufficient supply of foam fluid in each area, and makes full use of water pressure and frost heave force from multiple domains to achieve plugging triggering under various conditions. Through elastic deformation, the foam fluid in the excitation pipeline is prompted to migrate to the bulk liquid flower tube 21 and escape from the spraying structure 212 to the outside, ensuring the effectiveness of the formation of the foam fluid area under complex environment, ensuring the barrier to the water infiltration process, and reducing the occurrence of freeze-thaw damage.

[0060] Example 5

[0061] This embodiment provides a method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid. The difference from Embodiment 4 is that this embodiment limits the structure of the foam fluid storage mechanism 4.

[0062] Reference Figure 2 The foam fluid storage mechanism 4 includes a slurry storage chamber 41 and a cover plate 411, and a one-way exhaust valve is provided on the cover plate 411. The slurry storage chamber 41 is distributed in the top area of ​​the slope 8, and the cover plate 411 is detachably mounted on the slurry storage chamber 41 to achieve the sealing effect of the slurry storage chamber 41. After the cover plate 411 is removed, the slurry storage chamber 41 can be filled with liquid and injected.

[0063] In the present embodiment, the slurry storage chamber 41 provides sufficient foam fluid supply for the overall liquid equalization system 2 while improving the convenience of the foam fluid replenishment process. The cover plate 411 and the one-way exhaust valve in the slurry storage chamber 41 can achieve coordinated control of the pressure in the slurry storage chamber 41 at different stages by controlling the gas flow direction, thereby effectively avoiding the formation of a negative pressure environment in the slurry storage chamber 41 during the foam fluid escape process, achieving a long-term supply of foam fluid, ensuring the effective escape of the foam fluid in the excitation domain, and avoiding the occurrence of upward overflow when the foam fluid escapes under pressure.

[0064] Example 6

[0065] This embodiment provides a method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid. The difference from Embodiment 5 is that this embodiment further limits the structure of the spraying structure 212.

[0066] Specifically, refer to Figure 3 , several groups of spraying structures 212 are arranged at equal intervals, and each group of spraying structures 212 includes two spraying ports and two nozzles. The two spraying ports are opened on the spraying pipe 21, distributed in the same horizontal plane, and the angle between the axes of the two spraying ports is 120°. The nozzle is a conical lampshade structure with openings at both ends. The side with the larger opening of the conical lampshade structure is fixed at the spraying port and connected to the spraying pipe 21 through the spraying port. This design ensures that the foam fluid has sufficient pressure when it is injected externally. The structural arrangement of the left and right double spraying ports at the same height ensures the coverage of the externally injected foam fluid, thereby ensuring the blocking effect of the foam fluid on the water body.

[0067] Example 7

[0068] This embodiment provides a method for suppressing freeze-thaw damage of slopes in seasonally frozen areas using a foam fluid, which specifically includes the following steps:

[0069] Step 1: Level the slope 8 according to the pre-planned requirements.

[0070] Step 2: Lay the cushion layer 3 along the surface of the slope 8. The cushion layer 3 includes two layers of sandy soil with a thickness of 150 mm to 200 mm. After each layer of sandy soil is laid, it is compacted and covered with geotextile.

[0071] Step three, connect each group of internal pressure excitation pipes 221 through the first grouting pipe 2231, connect each group of external pressure excitation pipes 222 through the second grouting pipe 2232, and connect the internal pressure excitation pipes 221 and the external pressure excitation pipes 222 to the spray pipe 21. After the arrangement is completed, pour concrete to form a prefabricated structure of the outer covering layer-liquid equalization system.

[0072] Step 4: lay the outer covering layer-liquid equalization system prefabricated structure on the cushion layer 3 , so that the external pressure excitation pipeline 222 is embedded in the cushion layer 3 , and the spraying structure 212 of the liquid spraying pipe 21 faces the cushion layer 3 .

[0073] Step 5: Set the slurry storage chamber 41 on the upper part of the slope 8 , and connect the first slurry feeding pipe 2231 and the second slurry feeding pipe 2232 to the slurry storage chamber 41 .

[0074] Step 6: slowly fill the foam fluid into the slurry storage chamber 41 in batches, observe that the foam fluid level in the slurry storage chamber 41 remains constant within a certain period of time, and there is no liquid leakage at the connection of the prefabricated structure, then the structure assembly is qualified.

[0075] Step 7: The cover plate 411 provided with a one-way exhaust valve is buckled on the top of the slurry storage chamber 41, and the structural assembly is completed. When the channel water conveyance generates water pressure on the slope 8, or the slope 8 generates frost heave force when frost heaves, the excitation pipe undergoes elastic deformation under the action of the water pressure or frost heave force, prompting the foam fluid in the excitation pipe to migrate to the spray pipe 21 and escape outward through the spraying structure 212.

[0076] like Figure 5 As shown, when the foam fluid is not injected, when water infiltrates or water is enriched, the sand 5 is surrounded by water 6. At this time, the water 6 can move freely in the pores of the sand 5 and can stay for a long time. The volume of the water 6 changes with the temperature, resulting in freeze-thaw damage. After the foam fluid is injected, the sand 5 is wrapped by the liquid film 61, and the pores between the sand 5 are filled with gas 7. According to the action mechanism of the foam fluid, when flowing in the porous medium, the radius of the bubble is greater than the radius of the pore throat. The bubble must be deformed to pass through the pore throat. The capillary resistance generated by the bubble deformation produces a Jamin effect in the pore throat, and the fluid resistance increases significantly under this influence. As one of the necessary conditions for the freeze-thaw damage phenomenon, water 6 determines whether the freeze-thaw damage can occur. In summary, after the foam fluid is injected, due to the sharp increase in fluid resistance in the pores, a barrier effect is formed on the water infiltration process, which directly or indirectly reduces the water content of the cushion layer 3 and the slope 8 soil, and achieves the suppression of the slope freeze-thaw damage phenomenon.

[0077] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid, characterized in that: The method comprises the following steps: introducing foam fluid into the seasonally frozen area slope, wherein the foam fluid generates a resistance effect in the soil of the seasonally frozen area slope, inhibits water infiltration, reduces the soil moisture content, and achieves the inhibition of freeze-thaw damage to the seasonally frozen area slope.

2. The method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid according to claim 1, characterized in that: The seasonally frozen area slope comprises a slope (8), an outer covering layer (1) and a cushion layer (3), wherein the cushion layer (3) and the outer covering layer (1) are sequentially distributed outside the slope (8) from the inside to the outside; the foam fluid is introduced into the cushion layer (3) through an introduction device, The introduction device comprises a liquid distribution system (2) and a foam fluid storage mechanism (4); the liquid distribution system (2) is arranged between the outer covering layer (1) and the cushion layer (3); the liquid distribution system (2) comprises a liquid dispersion tube, the liquid dispersion tube comprises a plurality of groups of liquid spraying tubes (21), and a plurality of groups of spraying structures (212) are arranged on the side of the liquid spraying tube (21) facing the cushion layer (3); the liquid spraying tube (21) is connected to the foam fluid storage mechanism (4); after the foam fluid in the foam fluid storage mechanism (4) enters the liquid spraying tube (21), it escapes to the cushion layer (3) through the spraying structure (212).

3. The method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid according to claim 2, characterized in that: The homogenous liquid system (2) further comprises an excitation domain; The excitation domain comprises an excitation pipe arranged between the outer covering layer (1) and the cushion layer (3); the excitation pipe is connected to the foam fluid storage mechanism (4) on one hand, and is connected to the liquid spraying pipe (21) on the other hand; the foam fluid inside the foam fluid storage mechanism (4) enters the liquid spraying pipe (21) through the excitation pipe; The excitation pipe can be deformed under the action of water pressure or frost heave force, thereby prompting the foam fluid in the excitation pipe to migrate to the liquid spraying pipe (21) and escape outward through the spraying structure (212).

4. The method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid according to claim 3, characterized in that: The excitation pipelines include a plurality of groups of internal pressure excitation pipelines (221) and a plurality of groups of external pressure excitation pipelines (222); The internal pressure excitation pipes (221) are distributed in the outer covering layer (1), and a plurality of groups of internal pressure excitation pipes (221) are connected to each other through a first grouting pipe (2231), and the first grouting pipe (2231) is connected to a foam fluid storage mechanism (4); The external pressure excitation pipes (222) are distributed in the cushion layer (3), and a plurality of groups of external pressure excitation pipes (222) are interconnected via second grouting pipes (2232), and the second grouting pipes (2232) are connected to the foam fluid storage mechanism (4).

5. The method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid according to claim 4, characterized in that: The plurality of groups of liquid spray pipes (21) are arranged at equal intervals and distributed vertically along the slope (8); The plurality of groups of internal pressure excitation pipes (221) are arranged at equal distances, and the internal pressure excitation pipes (221) and the liquid spraying pipes (21) are perpendicular to each other, and the first grouting pipe (2231) is parallel to the liquid spraying pipe (21); The plurality of groups of external pressure excitation pipes (222) are arranged at equal distances, and the external pressure excitation pipes (222) and the liquid spraying pipes (21) are perpendicular to each other, and the second grouting pipe (2232) is parallel to the liquid spraying pipe (21).

6. The method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid according to claim 4, characterized in that: The tube wall (211) of the liquid spraying tube (21) is provided with a slurry outlet (23), and the liquid spraying tube (21) is connected to the excitation pipeline through the slurry outlet (23). The cross section of the internal pressure excitation pipe (221) is circular, the cross section of the external pressure excitation pipe (222) is a narrow and long rectangle / ellipse / rounded rectangle, and the contact area between the external pressure excitation pipe (222) and the cushion layer (3) is greater than the contact area between the internal pressure excitation pipe (221) and the outer covering layer (1).

7. The method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid according to claim 1, characterized in that: The foam fluid storage mechanism (4) comprises a slurry storage chamber (41) and a cover plate (411); The cover plate (411) is installed on the slurry storage chamber (41), and a one-way exhaust valve is provided on the cover plate (411).

8. The method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid according to claim 1, characterized in that: The cushion layer (3) is made of sand and / or crushed stone, and geotextiles (31) are evenly distributed in the cushion layer (3).

9. The method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid according to claim 1, characterized in that: Among the plurality of groups of spraying structures (212), each group of spraying structures (212) comprises two spraying ports and two spray heads; The two spraying ports are provided on the liquid spraying pipe (21), and the included angle between the axes of the two spraying ports is 120°; The spray head is a conical lampshade structure with openings at both ends, and the side with the larger opening of the conical lampshade structure is fixed at the spraying port and is connected to the liquid spraying pipe (21) through the spraying port.

10. The method for suppressing freeze-thaw damage of slopes in seasonally frozen areas by using foam fluid according to claim 4, characterized in that: The specific steps include: Step 1: laying a cushion layer (3) along the surface of the slope (8), wherein the cushion layer (3) comprises 1 to 3 sandy soil layers, and compacting each layer of sandy soil after it is laid, and then covering it with geotextile after compaction; Step 2: connect each group of internal pressure excitation pipes (221) through the first grouting pipe (2231), connect each group of external pressure excitation pipes (222) through the second grouting pipe (2232), and connect the internal pressure excitation pipes (221) and the external pressure excitation pipes (222) to the liquid spraying pipe (21). After the arrangement is completed, concrete pouring is performed to form a prefabricated structure of the outer covering layer-liquid distribution system; Step 3: Lay the outer covering layer-liquid distribution system prefabricated structure on the cushion layer (3); Step 4: placing the foam fluid storage mechanism (4) on the upper part of the slope (8), and connecting the first grouting pipe (2231) and the second grouting pipe (2232) to the foam fluid storage mechanism (4); Step 5: slowly fill the foam fluid into the foam fluid storage mechanism (4) in batches, observe that the foam fluid liquid level in the foam fluid storage mechanism (4) remains constant within a certain period of time, and there is no liquid leakage at the connection of the prefabricated mechanism, then the structure assembly is qualified; Step six, connect the cover plate (411) provided with a one-way exhaust valve to the foam fluid storage mechanism (4), and the structural assembly is completed. When the channel water conveyance generates water pressure on the slope (8), or the slope (8) generates frost heave force when frost heaves, the exciting pipe undergoes elastic deformation under the action of the water pressure or frost heave force, prompting the foam fluid in the exciting pipe to migrate to the spray pipe (21) and escape outward through the spraying structure (212).

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