A roadbed structure with active water repellent and drainage functions and its construction method

Abstract

The present invention discloses a roadbed structure with active water-repellent and drainage functions and a construction method thereof, belonging to the field of frozen soil roadbed-related roadbed structure engineering. The roadbed structure is provided with an anti-seepage layer, a temperature-control layer, a second high-suction geotextile, a second roadbed filler layer, a first high-suction geotextile, a first roadbed filler layer and a water-proof layer in sequence from top to bottom. By providing the anti-seepage layer, the water-proof layer and the water-repellent effect of the roadbed anti-seepage slope, liquid water on the outside and bottom of the roadbed is prevented from invading the internal filler of the roadbed through infiltration and capillary action. The heat release characteristics of the temperature-control layer are utilized, combined with the active drainage effect of the capillary and evaporation effects of the two layers of high-suction geotextiles, to jointly solve the problems of water accumulation and frost heave inside the roadbed, eliminate roadbed diseases, and prevent and control the "pot cover effect".

Description

Technical Field

[0001] The present invention relates to the field of seasonal frozen soil roadbed and roadbed structure engineering, and in particular to a roadbed structure with active water repellent and drainage functions and a construction method thereof. Background Art

[0002] Moisture intrusion and retention are key factors inducing roadbed damage. Roadbed construction in cold regions significantly alters the water-heat balance between the surface and the atmosphere. Existing monitoring data indicates that due to the impermeability of asphalt pavement and the large temperature differences in cold regions, liquid water and water vapor within the roadbed migrate toward the frozen zone during the freezing period, driven by temperature gradients and accumulating in the middle and upper parts of the roadbed, leading to frost heave and thaw settlement. The construction of wide roadbeds, in particular, exacerbates this accumulation trend, making frost heave and thaw settlement more prominent in cold-region roadbed construction.

[0003] Currently, drainage sand cushions and geosynthetics are commonly used in engineering projects to remove water trapped within the subgrade. However, drainage materials such as drainage sand cushions and conventional geotextiles are susceptible to capillary breakage due to their larger equivalent capillary radius compared to subgrade fillers. This capillary breakage occurs at the interface between fine-grained materials with relatively small pores and coarse-grained materials with relatively large pores. Consequently, drainage materials such as drainage sand cushions and conventional geotextiles are susceptible to capillary breakage at the interface with the subgrade filler. This capillary breakage prevents moisture from unsaturated soil from flowing through the pores into the geosynthetics and drainage sand cushions, effectively blocking the escape of trapped water along these surfaces. Geosynthetics and drainage sand cushions only achieve drainage effectiveness when the soil is at or near saturation, allowing water to migrate from small pores to larger pores. This means that geosynthetics and drainage sand cushions only have a high water content when the soil is relatively high. However, for unsaturated subgrade fillers, this is not ideal. Summary of the Invention

[0004] In response to the above-mentioned problems in the prior art, the present invention provides a roadbed structure with active water-repellent and drainage functions and a construction method thereof, which solves the problem that the drainage effect of the roadbed in the prior art is not ideal.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows: the present invention provides a roadbed structure with active water repellent and drainage functions, which includes a water-proof layer, which is laid on the leveled and compacted natural ground, and the laying depth of the water-proof layer is d4;

[0006] A first roadbed filler layer is laid on top of the waterproof layer, and a first high-suction geotextile is laid on top of the first roadbed filler layer. The laying depth of the first high-suction geotextile is d3;

[0007] A second roadbed filler layer is laid on top of the first high-suction geotextile, and a second high-suction geotextile is laid on top of the second roadbed filler layer. The laying depth of the second high-suction geotextile is d2;

[0008] A temperature control layer is laid on the top of the second high-suction geotextile, and an anti-seepage layer is laid on the top of the temperature control layer. The laying depth of the anti-seepage layer is d1;

[0009] The filler surfaces of the water-proof layer and the anti-seepage layer are sprayed with an organic silicon aqueous solution;

[0010] The laying depth d2 of the second high-suction geotextile and the laying depth d1 of the anti-seepage layer are both above the maximum freezing depth of the roadbed fill; the laying depth d2 of the second high-suction geotextile is located at the position where water accumulates after migration in the roadbed; the laying depth d3 of the first high-suction geotextile is located below the maximum freezing depth of the roadbed fill; both sides of the first high-suction geotextile and the second high-suction geotextile are located on the outer sides of the roadbed.

[0011] Furthermore, subgrade anti-seepage slopes are provided on both sides of the waterproof layer, the first subgrade filling layer, the second subgrade filling layer, the temperature control layer and the anti-seepage layer; and both sides of the first high-suction geotextile and the second high-suction geotextile are placed on the subgrade anti-seepage slopes.

[0012] Furthermore, the first high-suction geotextile and the second high-suction geotextile are both made of polyester materials.

[0013] Furthermore, the penetration depth of the organic silicon aqueous solution is greater than 2 / 3 of the loose thickness of the anti-seepage layer and the waterproof layer.

[0014] Furthermore, the thickness of the water-isolating layer is greater than the capillary rise height of the filler itself.

[0015] Furthermore, the mass concentration of the organosilicon aqueous solution is greater than 10%.

[0016] The present invention also provides a construction method for a roadbed structure with active water repellency and drainage functions, which comprises:

[0017] Step 1: Determine the maximum freezing depth of the roadbed fill based on numerical simulation results, field test monitoring results, or construction experience at similar sites;

[0018] Step 2: After the natural ground is leveled and compacted, a water-proof layer of a preset thickness is laid on the natural ground. The laying depth d4 of the water-proof layer is below the maximum freezing depth of the roadbed fill.

[0019] Step 3: Continue the roadbed filling construction on the upper part of the waterproof layer and lay the first roadbed filling layer, and lay the first layer of high-suction geotextile on top of the first roadbed filling layer, with both sides of the first layer of high-suction geotextile located outside the two sides of the first roadbed filling layer respectively; the laying depth d3 of the first high-suction geotextile is below the maximum freezing depth of the roadbed fill;

[0020] Step 4: Continue the roadbed filling construction on the top of the first layer of high-suction geotextile and lay a second roadbed filling layer. Lay a second layer of high-suction geotextile on top of the second roadbed filling layer. The two sides of the second layer of high-suction geotextile are respectively located outside the two sides of the second roadbed filling layer. The laying depth d2 of the second high-suction geotextile is above the maximum freezing depth of the roadbed fill and is located at the location where the water in the roadbed is accumulated after migration.

[0021] Step 5: Continue the roadbed filling construction and lay the temperature control layer on the second layer of high-suction geotextile;

[0022] Step 6: Lay an anti-seepage layer on top of the temperature control layer to complete the filling of the roadbed structure.

[0023] Furthermore, in step 2, the waterproof layer is laid in layers. Specifically, the roadbed filler of the waterproof layer is spread and leveled at a laying depth d4, and the loose laying thickness is determined according to the data determined in the roadbed test section; then, an organic silicon aqueous solution with a mass concentration of greater than 10% is sprayed on the loosely laid roadbed filler, so that the penetration depth of the organic silicon aqueous solution is greater than 2 / 3 of the current layer of loosely laid roadbed filler. When the roadbed filler is at an optimal moisture content, it is compacted according to the compaction parameters; then, the above steps are repeated. When the total compacted thickness of the roadbed filler is greater than the required thickness of the waterproof layer, the waterproof layer construction is completed;

[0024] Before laying, the initial moisture content of the roadbed filler of the aquiclude layer needs to be tested. If the initial moisture content of the roadbed filler is lower than the optimum moisture content, the roadbed filler of the aquiclude layer will be spread and compacted at the laying depth d4 of the aquiclude layer. If the initial moisture content of the roadbed filler is higher than the optimum moisture content, the roadbed filler of the aquiclude layer will be aired to make the initial moisture content of the roadbed filler lower than the optimum moisture content before the roadbed filler of the aquiclude layer will be spread and compacted at the laying depth d4 of the aquiclude layer.

[0025] An organic silicon aqueous solution with a mass concentration greater than 10% is evenly sprayed on the surface of the roadbed filler after paving but before compaction. The penetration depth of the organic silicon aqueous solution is greater than 2 / 3 of the loose thickness of the waterproof layer to complete the waterproof layer construction.

[0026] Furthermore, as another specific implementation of the aquiclude, in step 2, the roadbed filler of the aquiclude is mixed with hydrophobic organic material, and then the mixed material is spread and compacted at the laying depth d4 of the aquiclude to complete the construction of the aquiclude.

[0027] Furthermore, in step 5, the roadbed filler of the temperature control layer is PCM improved soil, the phase change temperature of the phase change material in the PCM improved soil is preferably 1.5-3°C, and the phase change enthalpy value is not less than 150 J / g; when laying the temperature control layer, the PCM improved soil is laid in layers on top of the second layer of high-suction geotextile, and compacted according to the compaction parameters. When the layers are filled to the laying depth d1 of the anti-seepage layer, the construction of the temperature control layer is completed.

[0028] The basic principle of the roadbed structure with active water repellency and drainage functions in this invention is as follows: the entire roadbed structure is sequentially arranged from top to bottom with an impermeable layer, a temperature control layer, a second high-suction geotextile, a second roadbed filler layer, a first high-suction geotextile, a first roadbed filler layer, and a water-insulating layer. The impermeable layer is waterproof and breathable. The filler in the impermeable layer is modified with silicone to increase the contact angle between the roadbed filler and liquid water, making it hydrophobic. This prevents water vapor from the underlying soil from condensing and melting above the impermeable layer, and prevents liquid water that seeps down through cracks in the road surface from being retained in the roadbed filler due to the unsaturated nature of the roadbed soil, thereby increasing the moisture content of the roadbed soil. A temperature control layer is laid below the impermeable layer. The temperature control layer contains a phase change material. When the roadbed temperature drops, the phase change material releases latent heat to slow the temperature drop, inhibiting the formation of temperature gradients, reducing water vapor migration, and alleviating frost heave in the roadbed. The first high-suction geotextile and the second high-suction geotextile are set up. The high-suction geotextile has a smaller capillary equivalent radius than the roadbed filler, and can actively absorb moisture from the roadbed filler, and transfer the moisture to the high-suction geotextile on the exposed roadbed through the lateral drainage path. Due to the special material of the high-suction geotextile, the moisture on the exposed high-suction geotextile will evaporate rapidly under the action of wind and sunlight. Its evaporation rate is greater than the water supply rate, forming an internal and external suction gradient, so that liquid water is continuously discharged from the roadbed along the high-suction geotextile. Drainage will only stop when the matrix suction inside the roadbed filler is greater than or equal to the suction of the high-suction geotextile. It can effectively prevent the accumulation of moisture in the roadbed filler and further reduce the moisture content of the unsaturated roadbed. Due to the water absorption characteristics of the high-suction geotextile, the filler around the high-suction geotextile will produce an area with low moisture content and high suction, resulting in a head gradient between the filler around the high-suction geotextile and the filler in other positions, so that the excess water in the roadbed filler will continue to migrate to the high-suction geotextile and eventually be discharged from the roadbed, so that the moisture in the roadbed filler is maintained at a lower value, and ultimately reduce the amount of water migration from the unfrozen area to the frozen area during the freezing period and the amount of frost heave in the frozen area.

[0029] The roadbed filler used in the waterproof layer is a silicone-modified roadbed filler with excellent hydrophobicity, effectively preventing capillary water migration and surface water infiltration and infiltration, preventing the roadbed from replenishing internal soil moisture through capillary action. Finally, after the roadbed construction is completed, an organosilicon solution is sprayed on the roadbed anti-seepage slope to increase the contact angle between the roadbed filler and liquid water in the anti-seepage slope, reduce its permeability coefficient, and prevent rainwater from seeping along the roadbed anti-seepage slope. This method prevents water infiltration from the outside and removes moisture from the roadbed from the inside, effectively preventing the occurrence of the "pot lid effect," reducing the incidence of roadbed disasters, extending the service life of the highway, and reducing highway maintenance costs. In the roadbed structure with active water-repellent and drainage functions, the hydrophobic effect of the anti-seepage layer, the waterproof layer and the anti-seepage slope of the roadbed is set to prevent liquid water from the outside and bottom of the roadbed from invading the internal filling of the roadbed through infiltration and capillary action. The heat release characteristics of the temperature control layer are utilized, combined with the active drainage effect of the capillary and evaporation effects of the two layers of high-suction geotextiles to jointly solve the problems of water accumulation and frost heave inside the roadbed, eliminate roadbed diseases, and prevent and control the "pot cover effect".

[0030] The beneficial effects of the present invention are: 1. The roadbed structure of the present invention can actively remove liquid water accumulated inside the roadbed due to migration, prevent the occurrence of the "pot lid effect", and maintain the water content of the roadbed filler at a low level, thereby ensuring the hydrothermal stability of the roadbed.

[0031] 2. Compared with the existing roadbed "pot cover effect" prevention measures, the roadbed structure of the present invention has the characteristics of convenient construction and low cost.

[0032] 3. The high-suction geotextile used in the roadbed of the present invention is aging-resistant, low-temperature-resistant, and can be used in severe cold conditions. Compared with other geosynthetics, it has a stronger drainage effect and has the ability of active drainage.

[0033] 4. The organic silicon solution used in the present invention is environmentally friendly, environmentally friendly, and non-toxic. The roadbed filler modified with the organic solution has a very long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The schematic diagram of the structure of a roadbed structure with active water repellent and drainage functions.

[0035] Among them, 1. Water-proof layer; 2. First roadbed filling layer; 3. First high-suction geotextile; 4. Second roadbed filling layer; 5. Second high-suction geotextile; 6. Temperature control layer; 7. Anti-seepage layer; 8. Roadbed anti-seepage slope. DETAILED DESCRIPTION

[0036] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0037] like Figure 1 As shown, the present invention provides a roadbed structure with active water-repellent and drainage functions, which includes a waterproof layer 1, which is laid on the leveled and compacted natural ground. The laying depth of the waterproof layer 1 is d4; the thickness of the waterproof layer 1 is greater than the capillary rise height of its own filler.

[0038] A first roadbed filler layer 2 is laid on the top of the waterproof layer 1 , and a first high-suction geotextile 3 is laid on the top of the first roadbed filler layer 2 . The laying depth of the first high-suction geotextile 3 is d3 .

[0039] A second roadbed filler layer 4 is laid on the top of the first high-suction geotextile 3 , and a second high-suction geotextile 5 is laid on the top of the second roadbed filler layer 4 . The laying depth of the second high-suction geotextile 5 is d2 .

[0040] A temperature control layer 6 is laid on the top of the second high-suction geotextile 5 , and an anti-seepage layer 7 is laid on the top of the temperature control layer 6 . The laying depth of the anti-seepage layer 7 is d1 .

[0041] The filler surfaces of the waterproof layer 1 and the anti-seepage layer 7 are sprayed with an organic silicon aqueous solution; the mass concentration of the organic silicon aqueous solution is greater than 10%, and the penetration depth of the organic silicon aqueous solution is greater than 2 / 3 of the loose thickness of the anti-seepage layer 7 and the waterproof layer 1; preferably, the above-mentioned organic silicon solution can be an organic silicon solution whose main components are dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (chemical formula: C26H58ClNO3Si) and ethylene glycol (chemical formula: C2H602), and the commercial name is Zycosil or Zycosiol.

[0042] The laying depth d2 of the second high-suction geotextile 5 and the laying depth d1 of the anti-seepage layer 7 are both above the maximum freezing depth of the roadbed fill; the laying depth d2 of the second high-suction geotextile 5 is located at the position where moisture in the roadbed accumulates after migration; the laying depth d3 of the first high-suction geotextile 3 is located below the maximum freezing depth of the roadbed fill; both sides of the first high-suction geotextile 3 and the second high-suction geotextile 5 are located on the outer sides of the roadbed.

[0043] Preferably, the first high-suction geotextile 3 and the second high-suction geotextile 5 are both made of polyester materials. The polyester materials are composed of filament fibers and elastic fibers. The filament fibers are arranged in the warp and weft directions to form a load-bearing skeleton. The elastic fibers are interspersed among the filament fibers along the weft direction and have a good drainage effect.

[0044] Specifically, roadbed anti-seepage slopes 8 are provided on both sides of the waterproof layer 1, the first roadbed filling layer 2, the second roadbed filling layer 4, the temperature control layer 6 and the anti-seepage layer 7; both sides of the first high-suction geotextile 3 and the second high-suction geotextile 5 are placed on the roadbed anti-seepage slopes 8.

[0045] In this embodiment, the entire roadbed structure is sequentially arranged from top to bottom with an impermeable layer 7, a temperature-control layer 6, a second high-suction geotextile 5, a second roadbed filler layer 4, a first high-suction geotextile 3, a first roadbed filler layer 2, and a water-insulating layer 1. The impermeable layer 7 is waterproof and breathable. The filler in the impermeable layer 7, modified with organic silicone, increases the contact angle between the roadbed filler and liquid water, making it hydrophobic. This prevents water vapor from the underlying soil from condensing and melting above the impermeable layer 7, and prevents liquid water seeping down cracks in the road surface from being retained in the roadbed filler due to the unsaturated nature of the roadbed soil, thereby increasing the moisture content of the roadbed soil. A temperature-control layer 6 is laid below the impermeable layer 7. This layer contains a phase-change material. When the roadbed temperature drops, the phase-change material releases latent heat to slow the drop in roadbed temperature, inhibiting the formation of a temperature gradient, reducing water vapor migration, and alleviating frost heave. The first high-suction geotextile 3 and the second high-suction geotextile 5 are arranged such that the high-suction geotextile has a smaller capillary equivalent radius than the roadbed filler, and can actively absorb moisture from the roadbed filler and transfer the moisture to the high-suction geotextile on the exposed roadbed through a lateral drainage path. Due to the special material of the high-suction geotextile, the moisture on the exposed high-suction geotextile will evaporate rapidly under the action of wind and sunlight. Its evaporation rate is greater than the water supply rate, forming an internal and external suction gradient, so that liquid water is continuously discharged from the roadbed along the high-suction geotextile. Drainage will only stop when the matrix suction inside the roadbed filler is greater than or equal to the suction of the high-suction geotextile. This can effectively prevent the accumulation of moisture in the roadbed filler and further reduce the water content of the unsaturated roadbed. Due to the water absorption characteristics of the high-suction geotextile, the filler around the high-suction geotextile will produce an area with low moisture content and high suction, resulting in a head gradient between the filler around the high-suction geotextile and the filler in other positions, so that the excess water in the roadbed filler will continue to migrate to the high-suction geotextile and eventually be discharged from the roadbed, so that the moisture in the roadbed filler is maintained at a lower value, and ultimately reduce the amount of water migration from the unfrozen area to the frozen area during the freezing period and the amount of frost heave in the frozen area.

[0046] The roadbed filler used in the waterproof layer 1 is a roadbed filler modified with organic silicon, which has excellent hydrophobicity and can effectively prevent the migration of capillary water and the infiltration and infiltration of surface water, and prevent the roadbed from replenishing water to the internal soil through capillary action. Finally, after the roadbed construction is completed, an organic silicon solution is sprayed on the roadbed anti-seepage slope 8 to increase the contact angle between the roadbed filler and liquid water in the roadbed anti-seepage slope 8, reduce its permeability coefficient, and prevent rainwater from infiltrating along the roadbed anti-seepage slope 8. By the above method, water infiltration is prevented externally and water inside the roadbed is removed internally, thereby effectively preventing the occurrence of the "pot cover effect", reducing the incidence of roadbed disasters, extending the service life of the highway, and reducing the maintenance cost of the highway.

[0047] In the roadbed structure with active water-repellent and drainage functions, the hydrophobic effect of the anti-seepage layer 7, the water-isolating layer 1 and the roadbed anti-seepage slope 8 is set to prevent liquid water from the outside and bottom of the roadbed from invading the internal filling of the roadbed through infiltration and capillary action. The heat release characteristics of the temperature control layer 6 are utilized, combined with the active drainage effect of the capillary and evaporation effects of the two layers of high-suction geotextiles, to jointly solve the problems of water accumulation and frost heave inside the roadbed, eliminate roadbed diseases, and prevent and control the "pot cover effect".

[0048] The present invention also provides a construction method for a roadbed structure with active water repellency and drainage functions, which comprises:

[0049] Step 1: Determine the maximum freezing depth of the roadbed fill based on numerical simulation results, field test monitoring results, or construction experience at similar sites;

[0050] Step 2: After the natural ground is leveled and compacted, a water-proof layer 1 of a preset thickness is laid on the natural ground. The laying depth d4 of the water-proof layer 1 is below the maximum freezing depth of the roadbed fill.

[0051] Step 3: Continue the roadbed filling construction on the upper part of the waterproof layer 1 and lay the first roadbed filling layer 2, and lay the first layer of high-suction geotextile on top of the first roadbed filling layer 2, with both sides of the first layer of high-suction geotextile located outside the two sides of the first roadbed filling layer 2; the laying depth d3 of the first high-suction geotextile 3 is below the maximum freezing depth of the roadbed fill;

[0052] Step 4: Continue the roadbed filling construction on the top of the first layer of high-suction geotextile to lay a second roadbed filling layer 4, and lay a second layer of high-suction geotextile on top of the second roadbed filling layer 4, with both sides of the second layer of high-suction geotextile located outside the second roadbed filling layer 4 respectively; the laying depth d2 of the second high-suction geotextile 5 is located above the maximum freezing depth of the roadbed fill and at the location where water in the roadbed accumulates after migration;

[0053] Step 5: Continue the roadbed filling construction on the second layer of high-suction geotextile and lay the temperature control layer 6;

[0054] Step 6: Lay the anti-seepage layer 7 on the top of the temperature control layer 6 to complete the filling of the roadbed structure.

[0055] Furthermore, in step 2, the waterproof layer 1 is laid in layers. Before laying, the initial moisture content of the roadbed filler of the waterproof layer 1 needs to be detected. If the initial moisture content of the roadbed filler is lower than the optimum moisture content, the roadbed filler of the waterproof layer 1 is flatly laid and compacted at the laying depth d4 of the waterproof layer 1; if the initial moisture content of the roadbed filler is higher than the optimum moisture content, the roadbed filler of the waterproof layer 1 needs to be aired to make the initial moisture content of the roadbed filler lower than the optimum moisture content, and then the roadbed filler of the waterproof layer 1 is flatly laid and compacted at the laying depth d4 of the waterproof layer 1;

[0056] An organic silicon aqueous solution with a mass concentration greater than 10% is evenly sprayed on the surface of the roadbed filler after paving but before compaction. The penetration depth of the organic silicon aqueous solution is greater than 2 / 3 of the loose thickness of the waterproof layer 1, and the construction of the waterproof layer 1 is completed.

[0057] Furthermore, as another specific embodiment of the waterproof layer 1, in step 2, the roadbed filler of the waterproof layer 1 is mixed with hydrophobic organic materials, and then the mixed material is flatly spread and compacted at the laying depth d4 of the waterproof layer 1 to complete the construction of the waterproof layer 1.

[0058] Furthermore, in step 5, the roadbed filler of the temperature control layer 6 is PCM improved soil, the phase change temperature of the phase change material in the PCM improved soil is preferably 1.5-3°C, and the phase change enthalpy value is not less than 150 J / g; when laying the temperature control layer 6, the PCM improved soil is laid in layers on top of the second layer of high-suction geotextile, and compacted according to the compaction parameters. When the layers are filled to the laying depth d1 of the anti-seepage layer 7, the construction of the temperature control layer 6 is completed.

[0059] The phase change material in the PCM-modified soil undergoes a phase change and releases heat during the cooling process of the temperature-control layer 6. This inhibits soil moisture migration, suppresses the formation of temperature gradients, reduces frost heave, and prevents the pot-lid effect. Compared to existing measures to prevent the pot-lid effect, this roadbed construction method is easier to construct and more cost-effective.

Claims

1. A roadbed structure with active water repellency and drainage functions, characterized in that: It includes a waterproof layer, which is laid on the leveled and compacted natural ground, and the laying depth of the waterproof layer is d4; A first roadbed filler layer is laid on top of the waterproof layer, and a first high-suction geotextile is laid on top of the first roadbed filler layer. The laying depth of the first high-suction geotextile is d3; A second roadbed filler layer is laid on top of the first high-suction geotextile, and a second high-suction geotextile is laid on top of the second roadbed filler layer. The laying depth of the second high-suction geotextile is d2; A temperature control layer is laid on the top of the second high-suction geotextile, and an anti-seepage layer is laid on the top of the temperature control layer. The laying depth of the anti-seepage layer is d1; The filler surfaces of the water-proof layer and the anti-seepage layer are sprayed with an organic silicon aqueous solution; The laying depth d2 of the second high-suction geotextile and the laying depth d1 of the anti-seepage layer are both above the maximum freezing depth of the roadbed fill; the laying depth d2 of the second high-suction geotextile is located at the position where water accumulates after migration in the roadbed; the laying depth d3 of the first high-suction geotextile is located below the maximum freezing depth of the roadbed fill; both sides of the first high-suction geotextile and the second high-suction geotextile are located on the outer sides of the roadbed.

2. The roadbed structure with active water repellency and drainage functions according to claim 1, characterized in that: Roadbed anti-seepage slopes are provided on both sides of the waterproof layer, the first roadbed filling layer, the second roadbed filling layer, the temperature control layer and the anti-seepage layer; and both sides of the first high-suction geotextile and the second high-suction geotextile are placed on the roadbed anti-seepage slopes.

3. The roadbed structure with active water repellency and drainage functions according to claim 1, characterized in that: The first high-suction geotextile and the second high-suction geotextile are both made of polyester materials.

4. The roadbed structure with active water repellency and drainage functions according to claim 1, characterized in that: The penetration depth of the organic silicon aqueous solution is greater than 2 / 3 of the loose thickness of the anti-seepage layer and the waterproof layer.

5. The roadbed structure with active water repellency and drainage functions according to claim 1, characterized in that: The thickness of the water-proof layer is greater than the capillary rise height of the filler itself.

6. The roadbed structure with active water repellency and drainage functions according to claim 5, characterized in that: The mass concentration of the organosilicon aqueous solution is greater than 10%.

7. A construction method for a roadbed structure with active water repellency and drainage functions according to any one of claims 1 to 6, characterized in that: include: Step 1: Determine the maximum freezing depth of the roadbed fill based on numerical simulation results, field test monitoring results, or construction experience at similar sites; Step 2: After the natural ground is leveled and compacted, a water-proof layer of a preset thickness is laid on the natural ground. The laying depth d4 of the water-proof layer is below the maximum freezing depth of the roadbed fill. Step 3: Continue the roadbed filling construction on the upper part of the waterproof layer and lay the first roadbed filling layer, and lay the first layer of high-suction geotextile on top of the first roadbed filling layer, with both sides of the first layer of high-suction geotextile located outside the two sides of the first roadbed filling layer respectively; the laying depth d3 of the first high-suction geotextile is below the maximum freezing depth of the roadbed fill; Step 4: Continue the roadbed filling construction on the top of the first layer of high-suction geotextile and lay a second roadbed filling layer. Lay a second layer of high-suction geotextile on top of the second roadbed filling layer. The two sides of the second layer of high-suction geotextile are respectively located outside the two sides of the second roadbed filling layer. The laying depth d2 of the second high-suction geotextile is above the maximum freezing depth of the roadbed fill and is located at the location where the water in the roadbed is accumulated after migration. Step 5: Continue the roadbed filling construction and lay the temperature control layer on the second layer of high-suction geotextile; Step 6: Lay an anti-seepage layer on top of the temperature control layer to complete the filling of the roadbed structure.

8. The construction method of the roadbed structure with active water repellency and drainage functions according to claim 7, characterized in that: In step 2, the waterproof layer is laid in layers. Before laying, the initial moisture content of the roadbed filler of the waterproof layer needs to be tested. If the initial moisture content of the roadbed filler is lower than the optimum moisture content, the roadbed filler of the waterproof layer is flattened and compacted at the laying depth d4 of the waterproof layer; if the initial moisture content of the roadbed filler is higher than the optimum moisture content, the roadbed filler of the waterproof layer needs to be aired to make the initial moisture content of the roadbed filler lower than the optimum moisture content, and then the roadbed filler of the waterproof layer is flattened and compacted at the laying depth d4 of the waterproof layer; An organic silicon aqueous solution with a mass concentration greater than 10% is evenly sprayed on the surface of the roadbed filler after paving but before compaction. The penetration depth of the organic silicon aqueous solution is greater than 2 / 3 of the loose thickness of the waterproof layer to complete the waterproof layer construction.

9. The construction method of the roadbed structure with active water repellency and drainage functions according to claim 7, characterized in that: In step 2, the roadbed filler of the aquiclude is mixed with the hydrophobic organic material, and then the mixed material is spread and compacted at the laying depth d4 of the aquiclude to complete the construction of the aquiclude.

10. The construction method of the roadbed structure with active water repellency and drainage functions according to claim 7, characterized in that: In step 5, the roadbed filler of the temperature control layer is PCM improved soil. The phase change temperature of the phase change material in the PCM improved soil is preferably 1.5-3°C, and the phase change enthalpy value is not less than 150 J / g. When laying the temperature control layer, the PCM improved soil is laid layer by layer on top of the second layer of high-suction geotextile and compacted according to the compaction parameters. When the layered filling reaches the laying depth d1 of the anti-seepage layer, the temperature control layer construction is completed.

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