Highway super-hydrophobic soft rock high-performance roadbed structure and construction method

Abstract

The application belongs to the technical field of highway construction, and particularly relates to a high-performance roadbed structure of super-hydrophobic soft rock of expressway and a construction method thereof. The high-performance roadbed structure comprises a foundation, a bottom water isolation area arranged on the foundation, a soft rock filling core area arranged on the bottom water isolation area, super-hydrophobic soft rock edge water isolation areas arranged on both sides of the soft rock filling core area, a super-hydrophobic soft rock cover water isolation area arranged on the soft rock filling core area, a constant-stiffness area arranged on the super-hydrophobic soft rock cover water isolation area, a pavement structure layer arranged on the constant-stiffness area, and a slope surface formed by outer side surfaces of the bottom water isolation area, the super-hydrophobic soft rock edge water isolation areas, the super-hydrophobic soft rock cover water isolation area and the constant-stiffness area, and a slope protection area arranged on the slope surface. The roadbed structure has good stability, stable stiffness and small post-construction settlement, can avoid cracking and subsidence of the soft rock roadbed, prolongs the service life of the roadbed and pavement, and improves the comfort of driving on the pavement.

Description

Technical Field

[0001] This invention belongs to the field of highway construction technology, specifically relating to a high-performance subgrade structure and construction method for superhydrophobic soft rock for expressways. Background Technology

[0002] Soft rock exhibits engineering characteristics such as disintegration, softening, and even mudification upon contact with water, leading to a sharp increase in deformation and a drastic decrease in strength, making it an unsuitable roadbed fill material. Currently, with the steady advancement of green highway construction, the "minimum borrowing and zero waste" roadbed filling method is an inevitable requirement. Soft rock is being utilized on a large scale as a roadbed fill material.

[0003] In practical engineering, the use of inorganic binders for improvement or cohesive soil sealing methods for the construction of soft rock subgrades has achieved certain results. However, it has also been found that cracking, subsidence, and other defects are more frequent in soft rock subgrades than in other subgrade fill materials. The root cause is the large settlement deformation and strength reduction of soft rock subgrades, with water being the primary contributing factor to these defects. Clearly, the technical challenges in constructing soft rock subgrades have not yet been resolved.

[0004] Achieving stable moisture content, constant stiffness, and minimal post-construction settlement in soft rock subgrades is crucial for high-quality construction. To address this, a high-performance subgrade structure and construction method for superhydrophobic soft rock for highways is proposed. Summary of the Invention

[0005] To address the problems in the prior art, this invention discloses a high-performance subgrade structure and construction method for superhydrophobic soft rock for highways, and specifically discloses the following technical solutions:

[0006] A high-performance subgrade structure for superhydrophobic soft rock for highways includes a foundation, a bottom waterproof zone laid on top of the foundation, a soft rock core zone laid on top of the bottom waterproof zone, superhydrophobic soft rock edging drainage zones on both sides of the soft rock core zone, a superhydrophobic soft rock capping drainage zone laid on top of the soft rock core zone, a stiffness-constant zone laid on top of the superhydrophobic soft rock capping drainage zone, a pavement structure layer laid on top of the stiffness-constant zone, and the outer surfaces of the bottom waterproof zone, the superhydrophobic soft rock edging drainage zone, the superhydrophobic soft rock capping drainage zone, and the stiffness-constant zone together constitute a slope surface, and a slope protection zone is laid on the slope surface.

[0007] It also includes a roadbed drainage system and a pavement drainage system. The roadbed drainage system includes a slope rapid flow channel, a platform intercepting ditch, and a slope toe drainage ditch. The platform intercepting ditch and the slope rapid flow channel are both set on the slope surface. The slope toe drainage ditch is set on the foundation near the slope toe. The platform intercepting ditch and the slope toe drainage ditch are both connected to the slope rapid flow channel. The top of the slope rapid flow channel is connected to the drainage outlet of the pavement drainage system.

[0008] Furthermore, the filler material of the bottom waterproof zone is stone chips or gravel of hard rock or medium-hard rock, the thickness of the bottom waterproof zone is not less than 50cm, and the maximum particle size of the stone material in the bottom waterproof zone does not exceed 2 / 3 of the layer thickness.

[0009] The filler material in the soft rock core area is soft rock, which includes relatively soft rock, soft rock and extremely soft rock. The paving layer thickness of the upper embankment in the soft rock core area is no more than 30cm, the paving layer thickness of the lower embankment in the soft rock core area is no more than 40cm, and the maximum particle size of the filler material in the soft rock core area is less than the layer thickness.

[0010] The filler material of the superhydrophobic soft rock edging drainage zone is superhydrophobic soft rock. The paving layer thickness of the upper embankment of the superhydrophobic soft rock edging drainage zone is no more than 30cm, the paving layer thickness of the lower embankment of the superhydrophobic soft rock edging drainage zone is no more than 40cm, and the maximum particle size of the filler material of the superhydrophobic soft rock edging drainage zone is no more than 10cm.

[0011] The filler material for the superhydrophobic soft rock capping the drainage zone is superhydrophobic soft rock, the thickness of the superhydrophobic soft rock capping the drainage zone is not less than 30cm, and the maximum particle size of the filler material for the superhydrophobic soft rock capping the drainage zone does not exceed 10cm.

[0012] The superhydrophobic soft rock is a soft rock permeated with superhydrophobic water solution;

[0013] The filler material in the stiffness constant stability zone is hard or medium-hard rock, the thickness of the stiffness constant stability zone is not less than 80cm, the paving layer thickness of the stiffness constant stability zone is not greater than 30cm, and the maximum particle size of the filler material in the stiffness constant stability zone is less than 10cm.

[0014] Furthermore, the slope protection area adopts a skeleton-planting grass structure, the skeleton of which is an arched concrete skeleton, and a water-blocking strip and drainage ditch are set on the arched concrete skeleton. The minimum thickness of the topsoil layer in the slope protection area is not less than 15cm.

[0015] A construction method for a high-performance subgrade structure made of superhydrophobic soft rock for highways includes the following steps:

[0016] S1. Construction preparation, including construction surveying, testing, foundation treatment, and construction of the test section;

[0017] S2. Conduct pre-fill compaction and compaction degree testing of the foundation surface layer;

[0018] S3. Carry out the construction of the bottom waterproofing zone;

[0019] S4. The loose paving thickness is controlled by setting up a grid, inserting poles, and hanging lines. At the same time, the material is fed, spread, leveled, and oversized stones are crushed in the first layer of soft rock core filling area and the first layer of superhydrophobic soft rock edge drainage area.

[0020] S5. Based on the volume of soft rock in the first layer of superhydrophobic soft rock surrounding the hydrophobic zone, and according to the optimal mixing ratio and optimal water-emulsion ratio determined by the experiment in step S1, calculate the volume of superhydrophobic emulsion and water that need to be mixed in the first layer of superhydrophobic soft rock surrounding the hydrophobic zone.

[0021] S6. According to the superhydrophobic solution preparation process determined in step S1 for the test section, dilute and mix the superhydrophobic emulsion and water in step S5 to prepare the superhydrophobic solution required for the first layer of superhydrophobic soft rock edging hydrophobic zone.

[0022] S7. According to the process parameters determined in step S1 for spraying superhydrophobic solution, mixing solution with soft rock and loosening and drying, carry out the construction of spraying superhydrophobic emulsion, mixing emulsion with soft rock and loosening and drying within the hydrophobic zone of the first layer of superhydrophobic soft rock.

[0023] S8. Perform rough leveling of the first layer of superhydrophobic soft rock edging and drainage zone;

[0024] S9. Simultaneously carry out fine leveling construction of the first layer of superhydrophobic soft rock edging drainage zone and the first layer of soft rock core filling zone;

[0025] S10. According to the compaction process parameters determined in the test section in step S1, the compaction of the first layer of superhydrophobic soft rock edging drainage zone and the first layer of soft rock core filling zone is carried out simultaneously.

[0026] S11. Following the compaction quality testing methods, indicators, and standards determined for the test section in step S1, simultaneously conduct compaction quality testing on the first layer of superhydrophobic soft rock edging drainage zone and the first layer of soft rock core filling zone; if the compaction quality is qualified, complete the construction of the first layer of superhydrophobic soft rock edging drainage zone and the first layer of soft rock core filling zone; if the compaction quality is unqualified, identify the cause and carry out targeted treatment until the compaction quality is qualified.

[0027] S12. Repeat the construction steps from S4 to S11 in sequence to carry out the construction of the remaining layers until the top surface elevation of the soft rock core area is reached.

[0028] S13. Referring to step S4, carry out the feeding, spreading, leveling, and crushing of oversized stones in the first layer of superhydrophobic soft rock covering the drainage zone; and referring to the method in step S5, calculate the required volume of superhydrophobic emulsion and water; referring to the method in step S6, prepare the superhydrophobic solution; referring to the method in step S7, carry out the spraying of the superhydrophobic solution, mixing of the solution with the soft rock, and loosening and drying; referring to the methods in steps S8 to S11, carry out the rough leveling, fine leveling, compaction, and quality inspection of the first layer of superhydrophobic soft rock covering the drainage zone.

[0029] S14. Following the method in step S13, carry out the construction of the remaining layers of the superhydrophobic soft rock capping drainage zone until the top surface elevation of the superhydrophobic soft rock capping drainage zone is reached.

[0030] S15. Carry out the construction of material feeding, spreading, leveling, compaction and quality testing in the stiffness constant zone until the top surface elevation of the roadbed is reached;

[0031] S16. Carry out the construction of slope protection zone and slope rapid flow channel;

[0032] S17. Carry out roadbed repair and handover acceptance;

[0033] S18. After the roadbed has passed the handover and acceptance inspection, the pavement structure layer will be constructed.

[0034] Furthermore, the test in step S1 involves sampling and testing the undisturbed soil of the subgrade base, soft rock, medium-hard rock, and hard rock rubble or gravel to be used as subgrade fill material before subgrade construction.

[0035] The test soil samples included undisturbed soil of the roadbed base, soft rock and superhydrophobic soft rock, medium-hard rock and hard rock with stone chips or gravel;

[0036] The test items for the undisturbed soil of the subgrade foundation include natural moisture content test, liquid limit test, plastic limit test, particle size analysis test and compaction test, to clarify the engineering classification and characteristics of the undisturbed soil of the foundation.

[0037] The test items for soft rock include natural water content test, liquid limit test, plastic limit test, particle size analysis test, compaction test, CBR test and saturated uniaxial compressive strength test, to clarify the road use characteristics, classification and applicable scope of soft rock;

[0038] The test items for superhydrophobic soft rock include compaction test, CBR test, superhydrophobicity test and water resistance test, to clarify the road use characteristics of superhydrophobic soft rock, and to propose the optimal mixing ratio of superhydrophobic soft rock and the optimal water-emulsion ratio of superhydrophobic solution.

[0039] The test items for stone chips or crushed stone in medium-hard and hard rocks include compaction test, CBR test and saturated uniaxial compressive strength test to clarify the road use characteristics and applicable scope of stone chips or crushed stone.

[0040] Furthermore, in step S14, the top surface of the superhydrophobic soft rock capping drainage zone is provided with a 4% drainage cross slope.

[0041] Furthermore, the permeability coefficient of the superhydrophobic soft rock edging and capping drainage zones is ≤10 ml / min; the superhydrophobic performance of these zones is tested visually. After the superhydrophobic soft rock compacted layer dries, water is splashed on it, and the formation of a lotus leaf effect is visually observed; the water absorption rate of the superhydrophobic soft rock edging and capping drainage zones is sampled on-site and subjected to specimen preparation and immersion tests. The water absorption rate is ≤2%, and the formula for calculating the water absorption rate of the specimen is as follows:

[0042]

[0043] In the formula, w is the water absorption rate of the specimen (%); m1 is the total mass of the test tube and the specimen after soaking in water (g); m2 is the total mass of the test tube and the specimen (g); and m is the mass of the test tube (g).

[0044] Furthermore, the specific steps of the compaction test for superhydrophobic soft rock are as follows:

[0045] A1. Prepare the soil for the test: Crush the soft rock, pass it through a 40mm round hole sieve, sieve the amount of material for the compaction test, dry it using the drying method, and weigh the dry soil.

[0046] A2. Preparation of superhydrophobic solutions: Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions;

[0047] A3. Preparing the sample: Prepare samples according to the quartering method. Prepare at least 5 samples for each water-to-emulsion ratio of superhydrophobic solution. Add superhydrophobic solution according to the principle of increasing by 1% to 3%. Mix the soil sample evenly and seal it for 24 hours for later use.

[0048] A4. Component fabrication and testing: Component fabrication and testing shall be carried out in accordance with the relevant requirements for compaction testing;

[0049] A5. Data processing: Obtain the optimal water content and maximum dry density of different superhydrophobic water pairs;

[0050] The specific steps of the CBR test for superhydrophobic soft rocks are as follows:

[0051] B1. Prepare the soil for the test: Crush the soft rock, pass it through a 20mm round hole sieve, sieve the amount of sample required for the CBR test, dry it using the drying method, and weigh the dry soil.

[0052] B2. Preparation of superhydrophobic solutions: Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions.

[0053] B3. Preparing the sample: Prepare the sample according to the quartering method. For each water-to-emulsion ratio superhydrophobic solution, add the superhydrophobic solution to the weighed dried soil sample according to the standards of optimum moisture content +2%, optimum moisture content +4%, and optimum moisture content +6%, respectively. Mix the soil sample evenly and seal it for four days and nights for later use.

[0054] B4. Drying treatment of the material: After the material is dried, the dried soil sample is air-dried naturally or dried in a 50℃ oven until the moisture content is reduced to the optimum moisture content and the surface is dry.

[0055] B5. Part Manufacturing and Testing: Part manufacturing and testing shall be carried out in accordance with the relevant requirements of CBR testing;

[0056] B6. Data processing: Obtain the load-bearing ratio and expansion rate of different superhydrophobic water pairs;

[0057] The specific steps for testing the superhydrophobicity of superhydrophobic soft rocks are as follows:

[0058] C1. Prepare the soil for the test: Crush the soft rock, pass it through a 20mm round hole sieve, sieve the amount of sample required for the CBR test, dry it using the drying method, and weigh the dry soil.

[0059] C2. Preparation of superhydrophobic solutions: Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions.

[0060] C3. Preparing the sample: Prepare the sample according to the quartering method. For each water-to-emulsion ratio superhydrophobic solution, add the superhydrophobic solution to the weighed dried soil sample according to the standards of optimum moisture content +2%, optimum moisture content +4%, and optimum moisture content +6%, respectively. Mix the soil sample evenly and seal it for four days and nights for later use.

[0061] C4. Drying treatment of the material: After the material is dried, the dried soil sample is air-dried naturally or dried in a 50℃ oven until the moisture content is reduced to the optimum moisture content and the surface is dry.

[0062] C5. Part Manufacturing and Demolding: Parts are manufactured according to the relevant requirements of the load-bearing ratio test, and then demolded.

[0063] C6. Superhydrophobicity test: Water is dripped onto the upper, lower, and side surfaces of the specimen, and the superhydrophobic effect of the specimen is visually tested.

[0064] The water resistance of superhydrophobic soft rocks is characterized by the decay of their uniaxial compressive strength before and after immersion in water. The specific steps of the uniaxial compressive strength test are as follows:

[0065] D1. Preparation of test specimens: Soft rock cylindrical specimens were prepared by dry method. The cylindrical specimens were φ50mm×100mm in size and dried in an oven.

[0066] D2. Preparation of superhydrophobic solutions: Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions.

[0067] D3. Immersion of specimens: Place the specimens into superhydrophobic solutions with different water-to-emulsion ratios, then remove, seal, and immerse the specimens for 24 hours for later use.

[0068] D4. Specimen drying treatment: After the curing process is completed, the cured specimens are air-dried naturally or dried in a 50℃ oven until the surface is dry.

[0069] D5. Soaking the specimen in water: Soak the dried specimen in water for four days and visually test the superhydrophobicity and disintegration of the specimen.

[0070] D6. Test: In accordance with the relevant provisions for uniaxial compressive strength test, the dried specimen in D1 and the water-soaked specimen in D5 shall be tested respectively.

[0071] D7. Data processing: Analyze the water resistance of superhydrophobic soft rocks;

[0072] The specific steps for the disintegration resistance test of superhydrophobic soft rocks are as follows:

[0073] E1. Prepare test specimens: Select round block-shaped specimens with a mass of 40g to 60g each, and the number of test specimens in each group shall not be less than 10, and dry them in an oven;

[0074] E2. Preparation of superhydrophobic solutions: Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions.

[0075] E3. Immersion of specimens: Place the specimens into superhydrophobic solutions with different water-to-emulsion ratios, then remove, seal, and immerse the specimens for 24 hours for later use.

[0076] E4. Start the test: After the component is sealed, conduct the test according to the test procedure for the disintegration resistance test;

[0077] E5. Data processing: Calculate the disintegration resistance index of superhydrophobic soft rocks.

[0078] Furthermore, in step S18, before the pavement structure layer is laid, the high-performance subgrade undergoes at least one full rainy season or a natural settlement stabilization period of 6 months.

[0079] Furthermore, in step S18, the pavement structure layer is laid after the settlement has stabilized, and the average subgrade settlement rate in the three months prior to the start of pavement structure layer laying is no more than 2 mm / month.

[0080] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0081] In this invention, the bottom waterproof zone can drain groundwater and surface water, isolate capillary water, enhance the friction between the roadbed and the foundation, and increase the stability of the roadbed; the superhydrophobic soft rock edging and sealing zones can prevent water infiltration into the roadbed and ensure the humidity stability of the soft rock roadbed; the stiffness-constant zone can ensure the stiffness stability of the roadbed. This invention ensures good roadbed stability, stiffness stability, and minimal post-construction settlement, avoiding cracking and subsidence of soft rock roadbeds, extending the service life of the roadbed and pavement, and improving the comfort of driving. Attached Figure Description

[0082] Figure 1 This is a schematic diagram of the structure of the present invention.

[0083] Figure 2 This is a flowchart of the construction method in this invention.

[0084] 1-Foundation, 2-Bottom waterproof zone, 3-Soft rock core filling zone, 4-Superhydrophobic soft rock capping drainage zone, 5-Stiffness constant zone, 6-Superhydrophobic soft rock edging drainage zone, 7-Slope protection zone, 8-Road structure layer. Detailed Implementation

[0085] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0086] Example 1

[0087] Reference Figure 1A high-performance subgrade structure of superhydrophobic soft rock for highways includes a foundation 1, a bottom waterproof zone 2 laid on top of the foundation 1, a soft rock core zone 3 laid on top of the bottom waterproof zone 2, superhydrophobic soft rock edge drainage zones 6 on both sides of the soft rock core zone 3, a superhydrophobic soft rock capping drainage zone 4 laid on top of the soft rock core zone 3, a stiffness-constant zone 5 laid on top of the superhydrophobic soft rock capping drainage zone 4, a pavement structure layer 8 laid on top of the stiffness-constant zone 5, the sides of the bottom waterproof zone 2, the outer sides of the superhydrophobic soft rock edge drainage zone 6, the sides of the superhydrophobic soft rock capping drainage zone 4, and the sides of the stiffness-constant zone 5 together form a slope surface, and a slope protection zone 7 is laid on the slope surface.

[0088] It also includes a roadbed drainage system and a pavement drainage system, which are effectively connected. The roadbed drainage system includes a slope sluice, a platform intercepting ditch, and a slope toe drainage ditch. The slope sluice is set on the slope surface and effectively connects with the pavement drainage system outlet, the platform intercepting ditch outlet, and the slope toe drainage ditch. When the platform intercepting ditch is longer than 500m, an outlet should be added at a suitable location in the middle to effectively connect with the slope sluice. The slope toe drainage ditch is set on a compacted foundation 1, and the distance from the roadbed slope toe should not be less than 2m. The pavement drainage system includes a centralized pavement surface drainage system, a central median drainage system, and a pavement edge drainage system. The centralized pavement surface drainage system includes an asphalt pavement cross slope and a shoulder water barrier. The central median drainage system consists of a waterproof layer, longitudinal drainage infiltration ditches, a collection trough, and transverse drainage pipes. The pavement edge drainage system preferably consists of a permeable filler collection ditch, longitudinal drainage pipes, transverse outlet pipes, and filter fabrics.

[0089] The filler material of the bottom waterproof zone 2 is stone chips or gravel of hard rock or medium-hard rock. The thickness of the bottom waterproof zone is not less than 50cm, and the maximum particle size of the stone material in the bottom waterproof zone 2 does not exceed 2 / 3 of the layer thickness.

[0090] In this embodiment, the height of the roadbed fill slope of the superhydrophobic soft rock high-performance roadbed structure of the expressway shall not exceed 20m; when the height of the roadbed fill slope exceeds 8m, a platform with a width of not less than 2m shall be set in the middle of the roadbed slope, and the height of each slope level shall not exceed 8m; the slope of the first-level slope shall not be steeper than 1:1.5, and the slope of the second and third-level slopes shall not be steeper than 1:1.75; a platform drainage ditch shall be set on the platform, and the platform drainage ditch shall be connected to the slope rapid flow channel.

[0091] In this embodiment, the soft rock includes relatively soft rock, soft rock, and extremely soft rock. The minimum bearing ratio and maximum particle size of the soft rock used as roadbed fill material comply with the relevant provisions of the roadbed section in the specification.

[0092] In this embodiment, the superhydrophobic soft rock refers to soil with superhydrophobic properties (lotus effect) formed by mixing superhydrophobic water solution with soft rock in an appropriate proportion and drying it. The superhydrophobic water solution is a diluted solution of superhydrophobic emulsion diluted with water, with a dilution ratio of 1:2 to 1:30. The superhydrophobic emulsion is a concentrated solution with an effective substance content of 50%, and the weight ratio of the effective substance to various roadbed fillers is 0.01% to 1%.

[0093] In this embodiment, the paving layer thickness of the lower embankment of the soft rock core area 3 is no more than 40cm, and the maximum particle size of the stone is less than 40cm; the paving layer thickness of the upper embankment is no more than 30cm, and the maximum particle size of the stone is less than 30cm. First, the soft rock core area 3 and the superhydrophobic soft rock edging drainage area 6 are simultaneously raked and compacted repeatedly using a large bulldozer with a special harrow attached and a sheep's foot roller. Second, after the superhydrophobic soft rock edging drainage area 6 has been repeatedly loosened and dried to near its optimum moisture content, it is compacted simultaneously with the superhydrophobic soft rock edging drainage area 6 according to the compaction process determined in the test section. The compaction process generally uses a vibratory roller with a self-weight of no less than 22t for compaction, and the compaction method is a combination of static compaction and vibratory compaction, with no less than 4 passes of vibratory compaction until the compaction is completed. After the compaction quality test is qualified, the next layer of construction is carried out until the top surface elevation of the soft rock core area 3 is reached.

[0094] In this embodiment, the filler material of the superhydrophobic soft rock edging drainage zone 6 is superhydrophobic soft rock. The paving layer thickness of the lower embankment portion of the superhydrophobic soft rock edging drainage zone 6 is no more than 40cm, and the paving layer thickness of the upper embankment portion is no more than 30cm. The maximum particle size of the filler material in the drainage zone 6 is no more than 10cm. The width of the superhydrophobic soft rock edging drainage zone 6 is no less than 1.0m and is consistent from top to bottom. The filler material of the superhydrophobic soft rock edging drainage zone 6 and the soft rock core filling zone 3 are fed, paved, and crushed with oversized stones simultaneously. First, within the width of the edging area, superhydrophobic soft rock road mixing method construction is carried out according to the superhydrophobic water spraying and mixing process determined in the test section. Under normal circumstances, the number of spraying and mixing passes should not be less than 3. Second, after uniform mixing, the mixture is loosened and dried according to the loosening and drying process determined in the test section until it reaches near the optimum moisture content. Third, fine leveling is carried out simultaneously with soft rock core filling area 3, and compaction is carried out according to the compaction process determined in the test section. The compaction process generally uses a vibratory roller with a self-weight of not less than 22t for compaction, and the compaction method is a combination of static compaction and vibratory compaction, with no less than 4 passes of vibratory compaction until the compaction is completed. Finally, compaction quality testing is carried out simultaneously with soft rock core filling area 3. After the compaction quality test is qualified, the construction of the next layer is carried out until the top surface elevation of soft rock core filling area 3 is reached.

[0095] In this embodiment, the filler material of the superhydrophobic soft rock-covered drainage zone 4 is superhydrophobic soft rock. The loose thickness of the superhydrophobic soft rock-covered drainage zone 4 does not exceed 25cm, and the maximum particle size of the filler material does not exceed 10cm. The compaction of the superhydrophobic soft rock-covered drainage zone 4 is carried out according to the compaction process determined in the test section. The compaction process generally involves using a vibratory roller with a self-weight of not less than 26t, combining static and vibratory compaction, with at least four passes of vibration compaction until the compaction is completed. After the compaction quality inspection is qualified, the next layer of construction proceeds until the top surface elevation of the superhydrophobic soft rock-covered drainage zone 4 is reached. The top surface of the superhydrophobic soft rock-covered drainage zone 4 has a 4% cross slope to ensure that water can be discharged from the roadbed in a timely manner through the cross slope.

[0096] In this embodiment, the fill material of the stiffness-constant stable zone 5 is stone chips or crushed stone from hard or medium-hard rock. The thickness of the stiffness-constant stable zone 5 is not less than 80 cm, the maximum particle size of the fill material in the stiffness-constant stable zone 5 does not exceed 10 cm, and the paving layer thickness of the stiffness-constant stable zone 5 is not greater than 30 cm. The compaction of the stiffness-constant stable zone 5 is carried out according to the compaction process determined by the test section. The compaction process generally uses a vibratory roller with a self-weight of not less than 26 t for compaction. The compaction method is a combination of static compaction and vibratory compaction, with no less than 6 passes of vibratory compaction until the compaction is completed. After the compaction quality test is qualified, the next layer of construction is carried out until the top surface elevation of the stiffness-constant stable zone 5 is reached.

[0097] Example 2

[0098] Reference Figure 2 A construction method for a high-performance subgrade structure of superhydrophobic soft rock for highways includes the following steps:

[0099] S1. Construction preparation, including construction surveying, testing, foundation treatment, and test road section;

[0100] S2. Conduct pre-fill compaction and compaction degree testing of the surface layer of foundation 1;

[0101] S3. Carry out the construction of the bottom waterproof zone 2;

[0102] S4. The loose paving thickness is controlled by setting up a grid, inserting poles, and hanging lines. At the same time, the material is fed, spread, leveled, and oversized stones are crushed in the first layer of soft rock core filling area 3 and the first layer of superhydrophobic soft rock edge drainage area 6.

[0103] S5. Based on the volume of soft rock in the first layer of superhydrophobic soft rock surrounding the hydrophobic zone 6, calculate the volume of superhydrophobic emulsion and water to be mixed in the first layer of superhydrophobic soft rock surrounding the hydrophobic zone 6 according to the optimal mixing ratio and optimal water-emulsion ratio determined by the experiment in step S1.

[0104] S6. According to the superhydrophobic solution preparation process determined in step S1 for the test section, dilute and mix the superhydrophobic emulsion and water in step S5 to prepare the superhydrophobic solution required for the first layer of superhydrophobic soft rock edging hydrophobic zone 6.

[0105] S7. According to the process parameters determined in step S1 for spraying superhydrophobic solution, mixing solution with soft rock, and loosening and drying, carry out the construction of superhydrophobic emulsion spraying, emulsion mixing with soft rock, and loosening and drying within the first layer of superhydrophobic soft rock edging hydrophobic zone 6.

[0106] S8. Perform rough leveling of the first layer of superhydrophobic soft rock edging drainage zone 6;

[0107] S9. Simultaneously carry out fine leveling construction of the first layer of superhydrophobic soft rock edging drainage zone 6 and the first layer of soft rock core filling zone 3;

[0108] S10. According to the compaction process parameters determined in the S1 test section, the compaction of the first layer of superhydrophobic soft rock edging drainage zone 6 and the first layer of soft rock core filling zone 3 shall be carried out simultaneously.

[0109] S11. Following the compaction quality testing methods, indicators, and standards determined for the S1 test section, simultaneously conduct compaction quality testing on the first layer of superhydrophobic soft rock edging drainage zone 6 and the first layer of soft rock core filling zone 3. If the compaction quality is qualified, complete the construction of the first layer of superhydrophobic soft rock edging drainage zone 6 and the first layer of soft rock core filling zone 3; if the compaction quality is unqualified, identify the cause and carry out targeted treatment until the compaction quality is qualified.

[0110] S12. Repeat the construction steps from S4 to S11 in sequence to carry out the construction of the remaining layers until the top surface elevation of the soft rock core area 3 is reached.

[0111] S13. Referring to step S4, carry out the feeding, spreading, leveling, and crushing of oversized stones in the first layer of superhydrophobic soft rock covering the drainage zone 4; and refer to the method in step S5 to calculate the required volume of superhydrophobic emulsion and water; refer to the method in step S6 to prepare the superhydrophobic solution; refer to the method in step S7 to carry out the spraying of the superhydrophobic solution, mixing of the solution with the soft rock, loosening and drying, etc.; refer to the methods in steps S8 to S11 to carry out the rough leveling, fine leveling, rolling and quality inspection of the first layer of superhydrophobic soft rock covering the drainage zone 4.

[0112] S14. Following the method in step S13, carry out the construction of the remaining layers of the superhydrophobic soft rock capping drainage zone 4 until the top surface elevation of the superhydrophobic soft rock capping drainage zone 4 is reached.

[0113] S15. Carry out the construction of stiffness constant zone 5, including material feeding, paving, leveling, compaction and quality testing, until the filling reaches the top elevation of the roadbed.

[0114] S16. Carry out the construction of slope protection zone 7 and slope rapid flow channel;

[0115] S17. Carry out roadbed repair and handover acceptance;

[0116] S18. After the roadbed has passed the handover and acceptance inspection, the construction of pavement structure layer 8 will proceed.

[0117] In this embodiment, the construction survey in step S1 is to conduct the construction survey in accordance with the relevant provisions of the "Technical Specification for Highway Subgrade Construction" (JTG / T3610-2019) before the subgrade construction.

[0118] In this embodiment, the test in step S1 is to take samples of the original soil of the subgrade base, soft rock, medium-hard rock and hard rock slag or gravel to be used as subgrade fill material before the subgrade construction.

[0119] The test soil samples included undisturbed soil of the roadbed base, soft rock and superhydrophobic soft rock, medium-hard rock and hard rock, and stone chips or gravel.

[0120] The test items for the undisturbed soil of the subgrade foundation include natural moisture content, liquid limit, plastic limit, particle size analysis, compaction, etc., to clarify the engineering classification and characteristics of the undisturbed soil of the foundation.

[0121] The test items for soft rock include natural water content, liquid limit, plastic limit, particle size analysis, compaction, CBR, saturated uniaxial compressive strength, etc., to clarify the road use characteristics, classification and applicable scope of soft rock;

[0122] The test items for superhydrophobic soft rock include compaction, CBR, superhydrophobicity, and water resistance, to clarify the road use characteristics of superhydrophobic soft rock, and to propose the optimal mixing ratio (superhydrophobic solution: soft rock) and the optimal water-emulsion ratio (water: superhydrophobic emulsion) of superhydrophobic soft rock.

[0123] Test items for stone chips or crushed stone in medium-hard and hard rocks include compaction, CBR, saturated uniaxial compressive strength, etc., to clarify the road use characteristics and applicable scope of stone chips or crushed stone;

[0124] In this embodiment, the foundation treatment in step S1 is to perform foundation treatment in accordance with the relevant provisions of the "Highway Subgrade Design Specification" (JTGD30-2015) and the construction drawing design before the subgrade filling construction.

[0125] In this embodiment, the test section in step S1 is a test section paved before the roadbed filling construction. The construction summary of the test section includes the following:

[0126] A1. Packing test results, inspection reports, etc.;

[0127] A2. Preparation processes of superhydrophobic solutions, such as dilution and mixing of superhydrophobic emulsions;

[0128] A3. Spraying of superhydrophobic solutions and number of spraying passes, mixing of solutions with soft rocks and number of mixing passes, loosening and drying of superhydrophobic soft rocks and number of loosening and drying passes, and other processes and parameters.

[0129] A4. Compaction process parameters for soft rock and superhydrophobic soft rock, including machinery and combination, loose thickness, number of rolling passes, rolling speed, rolling method, and control range of rolling moisture content.

[0130] A5. Compaction process parameters such as machinery and combination, loose thickness, number of rolling passes, rolling speed, and rolling method for compacting medium-hard rock and hard rock with stone chips or crushed stone.

[0131] A6. Compaction quality control methods, indicators and standards

[0132] A7. Permeability coefficient, superhydrophobic properties, and water absorption rate of the hydrophobic zone and capping zone of superhydrophobic soft rock.

[0133] In this embodiment, the top surface of the superhydrophobic soft rock capping the drainage zone in step S14 is provided with a 4% drainage cross slope.

[0134] In this embodiment, the permeability coefficient of the superhydrophobic soft rock edging and sealing zone is tested according to the T0971-2019 Asphalt Pavement Permeability Coefficient Test Method in the "Specifications for Field Testing of Highway Subgrade and Pavement" (JTG3450-2019). The permeability coefficient is ≤10ml / min, and two measurements are taken for each compacted layer every 200m.

[0135] In this embodiment, the superhydrophobic performance of the superhydrophobic soft rock edging and capping zone is tested by visual inspection. After the superhydrophobic soft rock compacted layer is dried, water is splashed on it, and the lotus leaf effect is visually inspected.

[0136] In this embodiment, the water absorption rate of the superhydrophobic soft rock edging and capping drainage zones was sampled on-site. The specimens were prepared and immersed in water for testing in accordance with the bearing ratio (CBR) test method in T0134-2019 of the "Highway Geotechnical Test Specification" (JTG3430-2020). The water absorption rate was ≤2%, and two samples were taken for each compacted layer every 200m.

[0137] The water absorption rate of the specimen is calculated according to formula (1).

[0138]

[0139] In the formula, w is the water absorption rate of the specimen (%); m1 is the total mass of the test tube and the specimen after soaking in water (g); m2 is the total mass of the test tube and the specimen (g); and m is the mass of the test tube (g).

[0140] In this embodiment, the specific steps of the compaction test for superhydrophobic soft rock are as follows:

[0141] A1. Prepare the soil for the test. Crush the soft rock, pass it through a 40mm round hole sieve, sieve the amount of material for the compaction test, dry it by the drying method, and weigh the dry soil.

[0142] A2. Preparation of superhydrophobic solutions. Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions.

[0143] A3. Preparing the sample. Prepare samples according to the quartering method. Prepare at least 5 samples for each water-to-emulsion ratio of superhydrophobic solution. Add superhydrophobic solution in increments of 1% to 3% and mix the soil samples evenly. Seal and preserve the sample for 24 hours for later use.

[0144] A4. Component Preparation and Testing. Component preparation and testing shall be carried out in accordance with the relevant requirements of compaction test in T0131-2019 of the "Specifications for Testing Geotechnical Engineering of Highways" (JTG3430-2020).

[0145] A5. Organize the data. Obtain the optimal water content and maximum dry density for different superphobic water pairs.

[0146] In this embodiment, the specific steps of the CBR test for superhydrophobic soft rock are as follows:

[0147] B1. Prepare the soil for the test. Crush the soft rock, pass it through a 20mm round hole sieve, sieve the amount of sample required for the CBR test, dry it by the drying method, and weigh the dry soil.

[0148] B2. Preparation of superhydrophobic solutions. Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions.

[0149] B3. Preparing the sample using the quartering method. Based on the determined optimum moisture content, for each water-to-emulsion ratio superhydrophobic solution, add the superhydrophobic solution to the weighed dried soil sample according to the optimum moisture content +2%, optimum moisture content +4%, and optimum moisture content +6%, respectively. Mix the soil sample evenly and seal it for four days and nights for later use.

[0150] B4. Drying treatment of the soil sample. After the soil sample has been dried, it is either air-dried naturally or dried in a 50℃ oven until the moisture content is reduced to the optimum moisture content and the surface is dry.

[0151] B5. Component Fabrication and Testing. Component fabrication and testing shall be carried out in accordance with the relevant requirements of the bearing ratio (CBR) test in T0134-2019 of the "Highway Geotechnical Testing Procedures" (JTG3430-2020).

[0152] B6. Organize the data. Obtain the carrying capacity and expansion rate of different superphobic water pairs.

[0153] In this embodiment, the specific steps for the superhydrophobicity test of superhydrophobic soft rock are as follows:

[0154] C1. Prepare the soil for the test. Crush the soft rock, pass it through a 20mm round hole sieve, sieve the amount of sample required for the CBR test, dry it by the drying method, and weigh the dry soil.

[0155] C2. Preparation of superhydrophobic solutions. Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions.

[0156] C3. Preparing the sample using the quartering method. Based on the determined optimum moisture content, for each water-to-emulsion ratio superhydrophobic solution, add the superhydrophobic solution to the weighed dried soil sample according to the optimum moisture content +2%, optimum moisture content +4%, and optimum moisture content +6%, respectively. Mix the soil sample evenly and seal it for four days and nights for later use.

[0157] C4. Drying treatment of the soil sample. After the soil sample has been dried, it is either air-dried naturally or dried in a 50℃ oven until the moisture content is reduced to the optimum moisture content and the surface is dry.

[0158] C5. Specimen Fabrication and Demolding. Specimens should be fabricated according to the relevant requirements of the Bearing Ratio (CBR) test in T0134-2019 of the "Highway Geotechnical Testing Procedures" (JTG3430-2020). Demolding should be performed after fabrication. Demolding should be done in a manner that avoids damaging the specimen.

[0159] C6. Superhydrophobicity test. Water is dripped onto the upper, lower, and side surfaces of the specimen, and the superhydrophobic effect of the specimen is visually tested.

[0160] In this embodiment, the water resistance of the superhydrophobic soft rock is characterized by the decay of its uniaxial compressive strength before and after immersion in water. The specific steps of the uniaxial compressive strength test are as follows:

[0161] D1. Prepare test specimens. Prepare cylindrical specimens of soft rock using a dry method. The cylindrical specimens should be φ50mm×100mm in size and dried in an oven.

[0162] D2. Preparation of superhydrophobic solutions. Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions.

[0163] D3. Immersion of Specimens. Place the specimens into superhydrophobic solutions with different water-to-emulsion ratios, then remove, seal, and immerse the specimens for 24 hours for later use.

[0164] D4. Specimen Drying Treatment. After the curing process is completed, the cured specimens are allowed to air dry naturally or dried in a 50℃ oven until the surface is dry.

[0165] D5. Soaking the specimen in water. Immerse the dried specimen in water for four days and visually test its superhydrophobicity and disintegration.

[0166] D6. Tests. Referring to the relevant provisions of the "Specifications for Rock Testing in Highway Engineering" (JTGE41-2005) T0221-2005 regarding uniaxial compressive strength testing, tests were conducted on the dried specimens in D1 and the water-soaked specimens in D5.

[0167] D7. Organize the data. Analyze the water resistance of superhydrophobic soft rocks.

[0168] In this embodiment, the specific steps of the disintegration resistance test of superhydrophobic soft rock are as follows:

[0169] E1. Prepare test specimens. Select round block-shaped specimens with a mass of 40g to 60g each. The number of specimens in each group should not be less than 10, and dry them in an oven.

[0170] E2. Preparation of superhydrophobic solutions. Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions.

[0171] E3. Immersion of Specimens. Place the specimens into superhydrophobic solutions with different water-to-emulsion ratios, then remove, seal, and immerse the specimens for 24 hours for later use.

[0172] E4. Begin the test. After the molding process is completed, conduct the test according to the test procedure of T0207-2005 Disintegration Resistance Test in the "Specifications for Rock Testing in Highway Engineering" (JTGE41-2005).

[0173] E5. Organize the data. Calculate the disintegration resistance index of superhydrophobic soft rocks.

[0174] In this embodiment, the optimal blending ratio and optimal water-emulsion ratio for superhydrophobic soft rocks are determined based on relevant test results.

[0175] In this embodiment, in step S18, before the pavement structure layer 8 is laid, the high-performance subgrade undergoes at least one full rainy season or a natural settlement stabilization period of 6 months.

[0176] In this embodiment, in step S18, the paving of the pavement structure layer 8 must be carried out after the settlement has stabilized. The average subgrade settlement rate in the three months prior to the commencement of paving of the pavement structure layer 8 is no greater than 2 mm / month.

[0177] In this invention, the bottom waterproof zone 2 can drain groundwater and surface water, isolate capillary water, enhance the friction between the roadbed and the foundation 1, and increase the stability of the roadbed; the superhydrophobic soft rock edging drainage zone 6 and the sealing drainage zone 4 can prevent water infiltration into the roadbed and ensure the humidity stability of the soft rock roadbed; the stiffness constant zone 5 can ensure the stiffness stability of the roadbed. This invention ensures good stability, stiffness stability, and small post-construction settlement of the roadbed, avoids cracking and subsidence of the soft rock roadbed, extends the service life of the roadbed and pavement, and improves the driving comfort of the road surface.

[0178] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A high-performance subgrade structure for superhydrophobic soft rock highways, characterized in that, The structure includes a foundation, a bottom waterproof zone above the foundation, a soft rock core zone above the bottom waterproof zone, superhydrophobic soft rock edging drainage zones on both sides of the soft rock core zone, a superhydrophobic soft rock capping drainage zone above the soft rock core zone, a stiffness-constant zone above the superhydrophobic soft rock capping drainage zone, and a road surface structure layer above the stiffness-constant zone. The bottom waterproof zone, the superhydrophobic soft rock edging drainage zone, the superhydrophobic soft rock capping drainage zone, and the outer surface of the stiffness-constant zone together constitute the slope surface, and a slope protection zone is laid on the slope surface. It also includes a roadbed drainage system and a pavement drainage system. The roadbed drainage system includes a slope rapid flow channel, a platform intercepting ditch, and a slope toe drainage ditch. The platform intercepting ditch and the slope rapid flow channel are both set on the slope surface. The slope toe drainage ditch is set on the foundation near the slope toe. The platform intercepting ditch and the slope toe drainage ditch are both connected to the slope rapid flow channel. The top of the slope rapid flow channel is connected to the drainage outlet of the pavement drainage system. The filler material of the bottom waterproof zone is stone chips or gravel of hard rock or medium-hard rock. The thickness of the bottom waterproof zone is not less than 50cm, and the maximum particle size of the stone material in the bottom waterproof zone does not exceed 2 / 3 of the layer thickness. The filler material in the soft rock core area is soft rock, which includes relatively soft rock, soft rock and extremely soft rock. The paving layer thickness of the upper embankment in the soft rock core area is no more than 30cm, the paving layer thickness of the lower embankment in the soft rock core area is no more than 40cm, and the maximum particle size of the filler material in the soft rock core area is less than the layer thickness. The filler material of the superhydrophobic soft rock edging drainage zone is superhydrophobic soft rock. The paving layer thickness of the upper embankment of the superhydrophobic soft rock edging drainage zone is no more than 30cm, the paving layer thickness of the lower embankment of the superhydrophobic soft rock edging drainage zone is no more than 40cm, and the maximum particle size of the filler material of the superhydrophobic soft rock edging drainage zone is no more than 10cm. The filler material for the superhydrophobic soft rock capping the drainage zone is superhydrophobic soft rock, the thickness of the superhydrophobic soft rock capping the drainage zone is not less than 30cm, and the maximum particle size of the filler material for the superhydrophobic soft rock capping the drainage zone does not exceed 10cm. The superhydrophobic soft rock is a soft rock permeated with superhydrophobic water solution; The filler material in the stiffness constant stability zone is hard or medium-hard rock, the thickness of the stiffness constant stability zone is not less than 80cm, the paving layer thickness of the stiffness constant stability zone is not greater than 30cm, and the maximum particle size of the filler material in the stiffness constant stability zone is less than 10cm.

2. The high-performance subgrade structure for superhydrophobic soft rock on highways according to claim 1, characterized in that, The slope protection area adopts a skeleton-planting grass structure. The skeleton of the skeleton-planting grass structure is an arched concrete skeleton. Water-blocking strips and drainage channels are set on the arched concrete skeleton. The minimum thickness of the topsoil layer in the slope protection area is not less than 15cm.

3. A construction method for a high-performance subgrade structure of superhydrophobic soft rock for highways according to any one of claims 1-2, characterized in that, Includes the following steps: S1. Construction preparation, including construction surveying, testing, foundation treatment, and construction of the test section; S2. Conduct pre-fill compaction and compaction degree testing of the foundation surface layer; S3. Carry out the construction of the bottom waterproofing zone; S4. The loose paving thickness is controlled by setting up a grid, inserting poles, and hanging lines. At the same time, the material is fed, spread, leveled, and oversized stones are crushed in the first layer of soft rock core filling area and the first layer of superhydrophobic soft rock edge drainage area. S5. Based on the volume of soft rock in the first layer of superhydrophobic soft rock surrounding the hydrophobic zone, and according to the optimal mixing ratio and optimal water-emulsion ratio determined by the experiment in step S1, calculate the volume of superhydrophobic emulsion and water that need to be mixed in the first layer of superhydrophobic soft rock surrounding the hydrophobic zone. S6. According to the superhydrophobic solution preparation process determined in step S1 for the test section, dilute and mix the superhydrophobic emulsion and water in step S5 to prepare the superhydrophobic solution required for the first layer of superhydrophobic soft rock edging hydrophobic zone. S7. According to the process parameters determined in step S1 for spraying superhydrophobic solution, mixing solution with soft rock and loosening and drying, carry out the construction of spraying superhydrophobic emulsion, mixing emulsion with soft rock and loosening and drying within the hydrophobic zone of the first layer of superhydrophobic soft rock. S8. Perform rough leveling of the first layer of superhydrophobic soft rock edging and drainage zone; S9. Simultaneously carry out fine leveling construction of the first layer of superhydrophobic soft rock edging drainage zone and the first layer of soft rock core filling zone; S10. According to the compaction process parameters determined in the test section in step S1, the compaction of the first layer of superhydrophobic soft rock edging drainage zone and the first layer of soft rock core filling zone is carried out simultaneously. S11. Following the compaction quality testing methods, indicators, and standards determined for the test section in step S1, simultaneously conduct compaction quality testing on the first layer of superhydrophobic soft rock edging drainage zone and the first layer of soft rock core filling zone; if the compaction quality is qualified, complete the construction of the first layer of superhydrophobic soft rock edging drainage zone and the first layer of soft rock core filling zone; if the compaction quality is unqualified, identify the cause and carry out targeted treatment until the compaction quality is qualified. S12. Repeat the construction steps from S4 to S11 in sequence to carry out the construction of the remaining layers until the top surface elevation of the soft rock core area is reached. S13. Referring to step S4, carry out the feeding, spreading, leveling, and crushing of oversized stones in the first layer of superhydrophobic soft rock covering the drainage zone; and referring to the method in step S5, calculate the required volume of superhydrophobic emulsion and water; referring to the method in step S6, prepare the superhydrophobic solution; referring to the method in step S7, carry out the spraying of the superhydrophobic solution, mixing of the solution with the soft rock, and loosening and drying; referring to the methods in steps S8 to S11, carry out the rough leveling, fine leveling, compaction, and quality inspection of the first layer of superhydrophobic soft rock covering the drainage zone. S14. Following the method in step S13, carry out the construction of the remaining layers of the superhydrophobic soft rock capping drainage zone until the top surface elevation of the superhydrophobic soft rock capping drainage zone is reached. S15. Carry out the construction of material feeding, spreading, leveling, compaction and quality testing in the stiffness constant zone until the top surface elevation of the roadbed is reached; S16. Carry out the construction of slope protection zone and slope rapid flow channel; S17. Carry out roadbed repair and handover acceptance; S18. After the roadbed has passed the handover and acceptance inspection, the pavement structure layer will be constructed.

4. The construction method for a high-performance subgrade structure of superhydrophobic soft rock for highways according to claim 3, characterized in that, The test in step S1 is to take samples of the original soil of the subgrade base, soft rock, medium-hard rock and hard rock rubble or gravel to be used as subgrade fill material before the subgrade construction. The test soil samples included undisturbed soil of the roadbed base, soft rock and superhydrophobic soft rock, medium-hard rock and hard rock with stone chips or gravel; The test items for the undisturbed soil of the subgrade foundation include natural moisture content test, liquid limit test, plastic limit test, particle size analysis test and compaction test, to clarify the engineering classification and characteristics of the undisturbed soil of the foundation. The test items for soft rock include natural water content test, liquid limit test, plastic limit test, particle size analysis test, compaction test, CBR test and saturated uniaxial compressive strength test, to clarify the road use characteristics, classification and applicable scope of soft rock; The test items for superhydrophobic soft rock include compaction test, CBR test, superhydrophobicity test and water resistance test, to clarify the road use characteristics of superhydrophobic soft rock, and to propose the optimal blending ratio of superhydrophobic soft rock and the optimal water-emulsion ratio of superhydrophobic solution. The test items for stone chips or crushed stone in medium-hard and hard rocks include compaction test, CBR test and saturated uniaxial compressive strength test to clarify the road use characteristics and applicable scope of stone chips or crushed stone.

5. The construction method for a high-performance subgrade structure of superhydrophobic soft rock for highways according to claim 3, characterized in that, In step S14, the top surface of the superhydrophobic soft rock capping the drainage zone is provided with a 4% drainage cross slope.

6. The construction method of a high-performance subgrade structure for superhydrophobic soft rock on highways according to claim 3, characterized in that, The permeability coefficient of the superhydrophobic soft rock edging and capping drainage zones is ≤10 ml / min. The superhydrophobic performance of these zones is tested visually. After the superhydrophobic soft rock compacted layer dries, water is splashed on it, and the formation of a lotus leaf effect is visually observed. Water absorption rates in both zones are sampled on-site and tested using specimen preparation and immersion tests. The water absorption rate is ≤2%. The formula for calculating the water absorption rate of the specimen is as follows: In the formula, w —Water absorption rate of the specimen (%); m1 —Total mass of the test tube and specimen after soaking in water (g); m2 —Total mass of the test tube and specimen (g); m —Mass of the test tube (g).

7. The construction method of a high-performance subgrade structure for superhydrophobic soft rock on highways according to claim 4, characterized in that, The specific steps for the compaction test of superhydrophobic soft rock are as follows: A1. Prepare the soil for the test: Crush the soft rock, pass it through a 40mm round hole sieve, sieve the amount of material for the compaction test, dry it using the drying method, and weigh the dry soil. A2. Preparation of superhydrophobic solutions: Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions; A3. Preparing the sample: Prepare samples according to the quartering method. Prepare at least 5 samples for each water-to-emulsion ratio of superhydrophobic solution. Add superhydrophobic solution according to the principle of increasing by 1% to 3%, mix the soil sample evenly, and seal it for 24 hours for later use. A4. Component fabrication and testing: Component fabrication and testing shall be carried out in accordance with the relevant requirements for compaction testing; A5. Data processing: Obtain the optimal water content and maximum dry density of different superhydrophobic water pairs; The specific steps of the CBR test for superhydrophobic soft rocks are as follows: B1. Prepare the soil for the test: Crush the soft rock, pass it through a 20mm round hole sieve, sieve the amount of sample required for the CBR test, dry it using the drying method, and weigh the dry soil. B2. Preparation of superhydrophobic solutions: Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions. B3. Preparing the sample: Prepare the sample according to the quartering method. For each water-to-emulsion ratio superhydrophobic solution, add the superhydrophobic solution to the weighed dried soil sample according to the standards of optimum moisture content +2%, optimum moisture content +4%, and optimum moisture content +6%, respectively. Mix the soil sample evenly and seal it for four days and nights for later use. B4. Drying treatment of the material: After the material is dried, the dried soil sample is air-dried naturally or dried in a 50℃ oven until the moisture content is reduced to the optimum moisture content and the surface is dry. B5. Part Manufacturing and Testing: Part manufacturing and testing shall be carried out in accordance with the relevant requirements of CBR testing; B6. Data processing: Obtain the load-bearing ratio and expansion rate of different superhydrophobic water pairs; The specific steps for testing the superhydrophobicity of superhydrophobic soft rocks are as follows: C1. Prepare the soil for the test: Crush the soft rock, pass it through a 20mm round hole sieve, sieve the amount of sample required for the CBR test, dry it using the drying method, and weigh the dry soil. C2. Preparation of superhydrophobic solutions: Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions. C3. Preparing the sample: Prepare the sample according to the quartering method. For each water-to-emulsion ratio superhydrophobic solution, add the superhydrophobic solution to the weighed dried soil sample according to the standards of optimum moisture content +2%, optimum moisture content +4%, and optimum moisture content +6%, respectively. Mix the soil sample evenly and seal it for four days and nights for later use. C4. Drying treatment of the material: After the material is dried, the dried soil sample is air-dried naturally or dried in a 50℃ oven until the moisture content is reduced to the optimum moisture content and the surface is dry. C5. Part Manufacturing and Demolding: Parts are manufactured according to the relevant requirements of the load-bearing ratio test, and then demolded. C6. Superhydrophobicity test: Water is dripped onto the upper, lower, and side surfaces of the specimen, and the superhydrophobic effect of the specimen is visually tested. The water resistance of superhydrophobic soft rocks is characterized by the decay of their uniaxial compressive strength before and after immersion in water. The specific steps of the uniaxial compressive strength test are as follows: D1. Preparation of test specimens: Soft rock cylindrical specimens were prepared by dry method. The cylindrical specimens were Φ50mm×100mm in size and dried in an oven. D2. Preparation of superhydrophobic solutions: Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions. D3. Immersion of specimens: Place the specimens into superhydrophobic solutions with different water-to-emulsion ratios, then remove, seal, and immerse the specimens for 24 hours for later use. D4. Specimen drying treatment: After the curing process is completed, the cured specimens are air-dried naturally or dried in a 50℃ oven until the surface is dry. D5. Soaking the specimen in water: Soak the dried specimen in water for four days and visually test the superhydrophobicity and disintegration of the specimen. D6. Test: In accordance with the relevant provisions for uniaxial compressive strength test, the dried specimen in D1 and the water-soaked specimen in D5 shall be tested respectively. D7. Data processing: Analyze the water resistance of superhydrophobic soft rocks; The specific steps for the disintegration resistance test of superhydrophobic soft rocks are as follows: E1. Prepare test specimens: Select round block-shaped specimens with a mass of 40g~60g each, and the number of test specimens in each group shall not be less than 10, and dry them in an oven; E2. Preparation of superhydrophobic solutions: Dilute the superhydrophobic emulsion at water-to-emulsion ratios of 1:4, 1:6, 1:8, and 1:10 respectively to prepare superhydrophobic solutions. E3. Immersion of specimens: Place the specimens into superhydrophobic solutions with different water-to-emulsion ratios, then remove, seal, and immerse the specimens for 24 hours for later use. E4. Start the test: After the component is sealed, conduct the test according to the test procedure for the disintegration resistance test; E5. Data processing: Calculate the disintegration resistance index of superhydrophobic soft rocks.

8. The construction method for the superhydrophobic soft rock high-performance subgrade structure for highways according to claim 3, characterized in that, In step S18, before the pavement structure layer is laid, the high-performance subgrade must undergo at least one full rainy season or a natural settlement stabilization period of 6 months.

9. The construction method for the superhydrophobic soft rock high-performance subgrade structure for highways according to claim 3, characterized in that, In step S18, the pavement structure layer is laid after the settlement has stabilized, and the average subgrade settlement rate in the three months prior to the start of pavement structure layer laying is no more than 2 mm / month.

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