A Comprehensive Performance Evaluation Method for Improved Coarse-grained Saline Soil

Abstract

This invention provides a method for evaluating the comprehensive performance of improved coarse-grained saline soil, belonging to the field of soil improvement technology. The method includes: improving coarse-grained saline soil using modifying materials to prepare specimens of the improved coarse-grained saline soil; testing the specimens to determine their mechanical property parameters, volumetric stability parameters, and microstructural characteristic parameters; constructing a comprehensive performance evaluation model for the improved coarse-grained saline soil using these parameters; determining a comprehensive performance evaluation index S based on the model; and evaluating the comprehensive performance of the improved coarse-grained saline soil using the index S. This invention provides a unified evaluation basis for the application and modification effect of improved coarse-grained saline soil.

Description

Technical Field

[0001] This invention belongs to the field of soil improvement technology, and relates to the improvement technology of coarse-grained saline soil. Specifically, it is a comprehensive performance evaluation method for improved coarse-grained saline soil, which aims to evaluate the comprehensive performance of coarse-grained saline soil after modification with rice husk ash-fiber-cement. Background Technology

[0002] Coarse-grained saline soils are widely distributed in cold and arid regions. In engineering applications, they commonly exhibit salt swelling and dissolution defects. Salt swelling manifests as follows: during cooling, sodium sulfate in the soil pore solution absorbs water and crystallizes to form mirabilite, resulting in dramatic volume expansion—up to more than three times its original volume. When used in road materials, this can cause bulging and uneven road surfaces. Dissolution occurs when coarse-grained saline soils come into contact with water, causing soluble salts to dissolve, leading to loss of interparticle bonding and structural collapse. This dissolution is particularly problematic when the soluble salt content in the soil exceeds 0.5%-1% and the soil permeability coefficient is not less than 10. -7 At a speed of cm / s, coarse-grained saline soil is prone to dissolution and collapse. When applied to road surface materials, it can cause sudden and uneven settlement, which seriously threatens the stability and safety of highway operation.

[0003] To address the salt swelling and collapsibility damage of coarse-grained saline soils, existing technologies employ modified materials for improvement. Many types of modified materials exist, with rice husk ash, fiber, and cement being one example. Rice husk ash, as an active material rich in amorphous SiO2, exhibits a highly variable effect in the cementitious system depending on its dosage; different dosages show significant differences in their impact on the material's macroscopic properties and microstructure. The reinforcing effect of fiber materials in soil improvement is also closely related to their dosage; different dosages result in significant differences in their effects on soil strength characteristics, deformation behavior, and structural stability. Cement, as the primary cementing material for soil solidification, affects soil strength development, structural density, and durability depending on its dosage. The road performance of coarse-grained saline soil can be greatly improved by modifying it with this material. However, there is no relevant technology in the existing technology to evaluate the road performance of the modified coarse-grained saline soil. In particular, there is a lack of relevant technology to comprehensively evaluate the mechanical properties, volume stability and microstructure characteristics of the modified coarse-grained saline soil. As a result, there is no unified evaluation basis for the application and modification effect of the modified coarse-grained saline soil. Summary of the Invention

[0004] In view of the technical problem described in the background section above, there is a lack of relevant technologies in the prior art for comprehensively evaluating the mechanical properties, volume stability and microstructure characteristics of improved coarse-grained saline soil. To address this technical problem, the present invention proposes a comprehensive performance evaluation method for improved coarse-grained saline soil.

[0005] This invention determines the mechanical property parameters, volumetric stability parameters, and microstructural characteristic parameters of improved coarse-grained saline soil specimens by testing them. Then, a comprehensive performance evaluation model coupling these three parameters is established. The comprehensive performance of the improved coarse-grained saline soil is evaluated based on this model. This not only achieves the coupling of the mechanical property parameters, volumetric stability parameters, and microstructural characteristic parameters of the improved coarse-grained saline soil, but also realizes the quantitative evaluation of its comprehensive performance, providing a unified evaluation basis for the application and modification effect of the improved coarse-grained saline soil.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for evaluating the comprehensive performance of improved coarse-grained saline soil includes the following steps: S1: Modify coarse-grained saline soil using modified materials and prepare specimens of the modified coarse-grained saline soil. S2: Test the specimens of the improved coarse-grained saline soil to determine the mechanical property parameters, volume stability parameters and microstructure characteristic parameters of the specimens of the improved coarse-grained saline soil. S3: Construct a comprehensive performance evaluation model for improved coarse-grained saline soil using mechanical property parameters, volume stability parameters, and microstructure characteristic parameters; S4: Determine the comprehensive performance evaluation index S based on the comprehensive performance evaluation model of the improved coarse-grained saline soil, and evaluate the comprehensive performance of the improved coarse-grained saline soil through the comprehensive performance evaluation index S.

[0007] Further specifying, in S4, the evaluation of the comprehensive performance of the improved coarse-grained saline soil using the comprehensive performance evaluation index S specifically involves: If S≥0.85, the comprehensive performance of the improved coarse-grained saline soil is excellent. If 0.70≤S<0.85, then the comprehensive performance of the improved coarse-grained saline soil is good. If 0.50≤S<0.70, then the overall performance of the improved coarse-grained saline soil is moderate. If S < 0.50, the overall performance of the improved coarse-grained saline soil is inferior.

[0008] Further specifying, in S3, In the formula, S is a comprehensive performance evaluation index, which is dimensionless; These are mechanical property parameters, dimensionless. The weights for mechanical properties are dimensionless. This is a dimensionless parameter representing volume stability. The weight for volume stability is dimensionless; These are microstructural characteristic parameters, which are dimensionless. The weights are the microstructural features.

[0009] Further specifying, the mechanical performance parameters It is determined based on the cohesion, internal friction angle, and compressive strength of the improved coarse-grained saline soil specimen. The volume stability parameters It was determined based on the salt swelling amount and the solution collapse coefficient of the improved coarse-grained saline soil specimen. The microstructure characteristic parameters It was determined based on the porosity and Ca / Si ratio of the improved coarse-grained saline soil specimen.

[0010] Further specifying, the mechanical performance parameters It is determined according to the following formula: In the formula, The cohesion of the improved coarse-grained saline soil specimen, in kPa; Cohesion of the plain soil, unit: kPa; This represents the proportion of cohesive force, which is dimensionless. The internal friction angle of the improved coarse-grained saline soil specimen, in degrees; The internal friction angle of the plain soil, in degrees; The percentage of the internal friction angle is dimensionless. The compressive strength of the improved coarse-grained saline soil specimen is given in MPa. The compressive strength of the unpaved soil, in MPa; This represents the proportion of compressive strength, dimensionless.

[0011] Further specifying, the volume stability parameter It is determined according to the following formula: In the formula, Salt swelling of the improved coarse-grained saline soil specimen, unit: mm; Salt swelling of the soil, unit: mm; The percentage of salt swelling is dimensionless. The solution collapse coefficient of the improved coarse-grained saline soil specimen is dimensionless. The solution collapse coefficient of the plain soil, in dimensionless form; This represents the proportion of the dissolution coefficient, which is dimensionless.

[0012] Further defining the microstructure characteristic parameters It is determined according to the following formula: In the formula, Porosity of the improved coarse-grained saline soil specimen, unit: dimensionless; Porosity of the raw soil, unit: dimensionless; Porosity percentage, dimensionless; The Ca / Si ratio of the improved coarse-grained saline soil specimen is dimensionless. The Ca / Si ratio of the raw soil is dimensionless. The Ca / Si ratio is dimensionless.

[0013] Further defining the weight of the mechanical properties Weights for volume stability Weights of microstructural features It is determined based on the eigenvector method; The proportion of cohesion Internal friction angle ratio and compressive strength ratio It is determined based on the eigenvector method; The proportion of salt swelling and salt swelling ratio It is determined based on the eigenvector method; porosity percentage and Ca / Si ratio It is determined based on the eigenvector method.

[0014] Further specifying, in S1, the modified material is formed by mixing rice husk ash, fiber and cement in a mass ratio of 15-25:0.1-0.5:6-10.

[0015] Further specifying, the fiber is basalt fiber.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention discloses a method for evaluating the comprehensive performance of improved coarse-grained saline soil. By testing specimens of the improved coarse-grained saline soil, the method determines the corresponding mechanical property parameters, volumetric stability parameters, and microstructural characteristic parameters of the specimens. Then, based on these mechanical property parameters, volumetric stability parameters, and microstructural characteristic parameters, a coupled comprehensive performance evaluation model is established. This model is used to evaluate the comprehensive performance of the improved coarse-grained saline soil. This method not only achieves the coupling of the mechanical property parameters, volumetric stability parameters, and microstructural characteristic parameters of the improved coarse-grained saline soil, but also realizes the quantitative evaluation of the comprehensive performance of the improved coarse-grained saline soil, providing a unified evaluation basis for the application and modification effect of the improved coarse-grained saline soil. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the improved comprehensive performance evaluation method for coarse-grained saline soil according to the present invention; Figure 2 The specimen is a modified coarse-grained saline soil. Detailed Implementation

[0018] The technical solution of the present invention will be further explained and described below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the following description of the application method of coarse-grained saline soil.

[0019] Cement has the greatest impact on the cohesion of solidified coarse-grained saline soil. In the solidified soil system, cement generates a large amount of cementing products through hydration. These cementing products form a continuous cementing network between the particles of the coarse-grained saline soil, transforming the originally loosely connected particles into integral structural units. The contact between particles gradually evolves from point contact to surface contact and even cemented connections, resulting in significant structural strength within the coarse-grained saline soil. This structural strength is mainly reflected in the shear resistance parameter as a significant increase in cohesion. Rice husk ash has the greatest impact on the internal friction angle. Rice husk ash mainly participates in the reaction as highly reactive amorphous silica, and its action path focuses more on regulating the particle arrangement and contact state. The fine and porous nature of rice husk ash particles can fill soil pores and improve gradation, making the contact between coarse and fine particles tighter. Simultaneously, its pozzolanic reaction consumes the calcium hydroxide produced by cement hydration, generating secondary cementing products that supplement and optimize the original structure. This process does not form a dominant cementitious framework like cement. Instead, it enhances the interlocking and friction conditions between particles through microscopic filling and interfacial reinforcement, thus greatly hindering particle slippage. To ensure that rice husk ash-cement can effectively act in the reinforced soil, and at the same time, the spatial constraint effect of basalt fibers can be used to improve coarse-grained saline soil.

[0020] In this invention, the modified material is formed by mixing rice husk ash, fiber, and cement in a mass ratio of 15-25:0.1-0.5:6-10. Specifically, the mass ratio of rice husk ash, fiber, and cement can be 15:0.1:6, 16:0.2:6, 17:0.2:6, 18:0.3:7, 19:0.3:7, 20:0.4:8, 21:0.4:9, 22:0.4:9, 23:0.5:10, 24:0.5:10, 25:0.5:10, etc., as long as the mass ratio is within the range of 15-25:0.1-0.5:6-10. As a preferred embodiment of this invention, the mass ratio of rice husk ash, fiber, and cement is 15:0.5:10.

[0021] The preferred fiber in this invention is basalt fiber. However, any fiber known to those skilled in the art that can be used as a road material may also be used.

[0022] See Figure 1 This invention proposes a method for evaluating the comprehensive performance of improved coarse-grained saline soil, which includes the following steps: S1: Modify coarse-grained saline soil using modified materials and prepare specimens of the modified coarse-grained saline soil. S2: Test the specimens of the improved coarse-grained saline soil to determine the mechanical property parameters, volume stability parameters and microstructure characteristics of the specimens. S3: Construct a comprehensive performance evaluation model for improved coarse-grained saline soil using mechanical property parameters, volume stability parameters, and microstructure characteristic parameters; S4: Determine the comprehensive performance evaluation index S based on the comprehensive performance evaluation model of the improved coarse-grained saline soil, and evaluate the comprehensive performance of the improved coarse-grained saline soil through the comprehensive performance evaluation index S.

[0023] In S4, the comprehensive performance of the improved coarse-grained saline soil is evaluated using the comprehensive performance evaluation index S, specifically as follows: If S≥0.85, the comprehensive performance of the improved coarse-grained saline soil is excellent. If 0.70≤S<0.85, then the comprehensive performance of the improved coarse-grained saline soil is good. If 0.50≤S<0.70, then the overall performance of the improved coarse-grained saline soil is moderate. If S < 0.50, the overall performance of the improved coarse-grained saline soil is inferior.

[0024] Specifically, when S≥0.85, the material exhibits high strength, excellent deformation resistance, and load-bearing capacity, making it suitable for high-grade projects such as highways, heavy-duty traffic roads, and roadbeds in cold regions; when 0.70≤S<0.85, the material can meet general traffic load requirements and is suitable for first-class highways, urban arterial roads, and ordinary national and provincial roadbeds; when 0.50≤S<0.70, although the material possesses a certain degree of stability, its long-term durability and deformation resistance are relatively limited, making it only suitable for rural roads, low-grade roads, and temporary construction roads; when S<0.50, the material exhibits insufficient strength, significant salt swelling or dissolution phenomena, and is not suitable for direct road paving, but can only be used as a non-load-bearing backfill material or requires further improvement.

[0025] In S3 In the formula, S is a comprehensive performance evaluation index, which is dimensionless; These are mechanical property parameters, dimensionless. The weights for mechanical properties are dimensionless. This is a dimensionless parameter representing volume stability. The weight for volume stability is dimensionless; These are microstructural characteristic parameters, which are dimensionless. The weights are the microstructural features.

[0026] Mechanical performance parameters It is determined based on the cohesion, internal friction angle, and compressive strength of the improved coarse-grained saline soil specimen. Volume stability parameters It was determined based on the salt swelling amount and the solution collapse coefficient of the improved coarse-grained saline soil specimen. Microstructure characteristic parameters It was determined based on the porosity and Ca / Si ratio of the improved coarse-grained saline soil specimen.

[0027] Mechanical performance parameters It is determined according to the following formula: In the formula, The cohesion of the improved coarse-grained saline soil specimen, in kPa; Cohesion of the plain soil, unit: kPa; This represents the proportion of cohesive force, which is dimensionless. The internal friction angle of the improved coarse-grained saline soil specimen, in degrees; The internal friction angle of the plain soil, in degrees; The percentage of the internal friction angle is dimensionless. The compressive strength of the improved coarse-grained saline soil specimen is given in MPa. The compressive strength of the unpaved soil, in MPa; This represents the proportion of compressive strength, dimensionless.

[0028] Volume stability parameters It is determined according to the following formula: In the formula, Salt swelling of the improved coarse-grained saline soil specimen, unit: mm; Salt swelling of the soil, unit: mm; The percentage of salt swelling is dimensionless. The solution collapse coefficient of the improved coarse-grained saline soil specimen is dimensionless. The solution collapse coefficient of the plain soil, in dimensionless form; This represents the proportion of the dissolution coefficient, which is dimensionless.

[0029] Microstructure characteristic parameters It is determined according to the following formula: In the formula, Porosity of the improved coarse-grained saline soil specimen, unit: dimensionless; Porosity of the raw soil, unit: dimensionless; Porosity percentage, dimensionless; The Ca / Si ratio of the improved coarse-grained saline soil specimen is dimensionless. The Ca / Si ratio of the raw soil is dimensionless. The Ca / Si ratio is dimensionless.

[0030] Weight of mechanical properties Weights for volume stability Weights of microstructural features It is determined based on the eigenvector method; Cohesion ratio Internal friction angle ratio and compressive strength ratio It is determined based on the eigenvector method; Salt swelling percentage and salt swelling ratio It is determined based on the eigenvector method; Porosity and Ca / Si ratio It is determined based on the eigenvector method.

[0031] This invention selects typical coarse-grained saline soil from Qinghai Province as the research object, and uses a rice husk ash-basalt fiber-cement composite improvement system to illustrate the comprehensive performance evaluation method of the improved coarse-grained saline soil of this invention: Tests showed that the cohesion of the unmodified coarse-grained saline soil (c0) was 18 kPa, and the internal friction angle of the unmodified soil was... 0 = 21 degrees, compressive strength q of plain soil u0 =0.232MPa, salt swelling of plain soil =1.45mm, the solution collapse coefficient of the plain soil =0.037, the porosity T0 of the plain soil is 25.51%, and the Ca / Si ratio R of the plain soil is... c0 1.19.

[0032] Specimens of improved coarse-grained saline soil were prepared. Testing revealed that the cohesion of the improved coarse-grained saline soil specimen was c=165kPa, and the internal friction angle of the improved coarse-grained saline soil specimen was... =38 degrees, compressive strength q of improved coarse-grained saline soil specimen u =12.736 MPa, salt swelling of the improved coarse-grained saline soil specimen =0.02mm, the solution collapse coefficient of the improved coarse-grained saline soil specimen =0.004, the porosity T of the improved coarse-grained saline soil specimen is 7.89%, and the Ca / Si ratio R of the improved coarse-grained saline soil specimen is... c =0.89.

[0033] Calculate the cohesive proportion using the eigenvector method. Internal friction angle ratio and compressive strength ratio The judgment matrix for the mechanical performance parameters is as follows: Calculate the geometric mean of each row using the eigenvector method: Row 1: (1×1×2)¹ / ³ = 1.26; Row 2: (1×1×2)¹ / ³ = 1.26; Row 3: (0.5×0.5×1)¹ / ³ = 0.63; Total: 1.26 + 1.26 + 0.63 = 3.15. .

[0034] Calculate the judgment matrix Maximum eigenvalue max The value is approximately 3.00, and the corresponding consistency index (CI) is calculated as follows: The consistency ratio (CR) is calculated as follows: Since CR=0<0.1, it indicates that the third-order judgment matrix has good consistency and the weight results are valid.

[0035] according to The cohesion of the aforementioned plain soil is c0 = 18 kPa, and the internal friction angle of the plain soil is... 0 = 21 degrees, compressive strength q of plain soil u0 =0.232MPa, cohesion c=165kPa of the improved coarse-grained saline soil specimen, and internal friction angle of the improved coarse-grained saline soil specimen. =38 degrees and compressive strength q of improved coarse-grained saline soil specimens u =12.736MPa Calculation .

[0036] The proportion of salt swelling was calculated using the eigenvector method. and salt swelling ratio Among them, the judgment matrix of volume stability parameters for: Calculate the geometric mean of each row using the eigenvector method. Row 1: (1×2)¹ / ² = 1.414; Row 2: (0.5×1)¹ / ² = 0.707; Total: 1.414 + 0.707 = 2.121. .

[0037] Since the second-order judgment matrix naturally satisfies the consistency requirement, no consistency check is needed, and RI is 0. Judgment Matrix The consistency deviation CR = 0 < 0.1 indicates that the second-order judgment matrix... It exhibits good consistency, and the weighting results are valid.

[0038] according to , And the amount of salt swelling in the aforementioned plain soil =1.45mm, the solution collapse coefficient of the plain soil =0.037, Salt swelling amount of the improved coarse-grained saline soil specimen =0.02mm and the solution collapse coefficient of the improved coarse-grained saline soil specimen =0.004 Calculation 0.955.

[0039] The proportion of salt swelling was calculated using the eigenvector method. and salt swelling ratio Among them, the judgment matrix of microstructure characteristic parameters for: Calculate the geometric mean of each row using the eigenvector method. Row 1: (1 × 3)¹ / ² = 1.732; Row 2: (0.333 × 1)¹ / ² = 0.577; Total: 1.732 + 0.577 = 2.309. .

[0040] Since the second-order judgment matrix naturally satisfies the consistency requirement, no consistency check is needed, and RI is 0. Judgment Matrix The consistency deviation CR = 0 < 0.1 indicates that the second-order judgment matrix... It exhibits good consistency, and the weighting results are valid.

[0041] according to , The porosity of the aforementioned soil, T0, is 25.51%, and the Ca / Si ratio, R, is... c0 =1.19, the porosity T of the improved coarse-grained saline soil is 7.89%, and the Ca / Si ratio R of the improved coarse-grained saline soil is... c =0.89 Calculation 2.825.

[0042] Calculate the weights of mechanical properties using the eigenvector method. Weights for volume stability Weights of microstructural features Among them, the judgment matrix corresponding to the overall performance for: Calculate the geometric mean of each row using the eigenvector method: Row 1: (1×2×3)¹ / ³ = 1.817; Row 2: (0.5×1×2)¹ / ³ = 1.000; Row 3: (0.333×0.5×1)¹ / ³ = 0.550; Total: 1.817 + 1.000 + 0.550 = 3.367. .

[0043] Calculate the judgment matrix The largest eigenvalue λ max ≈3.02, calculate the judgment matrix The consistency index (CI) is determined as follows: Calculate the judgment matrix The consistency ratio (CR) is calculated as follows: The RI value is determined based on the order of the judgment matrix. When the matrix order is 3, the RI value is 0.52, and since CR = 0.019... A value <0.1 indicates that the judgment matrix has good consistency, and the result is valid.

[0044] according to , , and the above , 0.955 The comprehensive performance evaluation index S=9.087 was calculated from 2.825, indicating that the comprehensive performance of the improved coarse-grained saline soil is excellent and can be applied to the paving of heavy traffic roads.

[0045] The above description is only used to illustrate the technical solutions of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing, those skilled in the art should understand that modifications can still be made to the technical solutions described above, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A method for evaluating the comprehensive performance of improved coarse-grained saline soil, characterized in that, Includes the following steps: S1: Modify coarse-grained saline soil using modified materials and prepare specimens of the modified coarse-grained saline soil. S2: Test the specimens of the improved coarse-grained saline soil to determine the mechanical property parameters, volume stability parameters and microstructure characteristic parameters of the specimens of the improved coarse-grained saline soil. S3: Construct a comprehensive performance evaluation model for improved coarse-grained saline soil using mechanical property parameters, volume stability parameters, and microstructure characteristic parameters; S4: Determine the comprehensive performance evaluation index S based on the comprehensive performance evaluation model of the improved coarse-grained saline soil, and evaluate the comprehensive performance of the improved coarse-grained saline soil through the comprehensive performance evaluation index S.

2. The method for evaluating the comprehensive performance of improved coarse-grained saline soil according to claim 1, characterized in that, In step S4, the comprehensive performance of the improved coarse-grained saline soil is evaluated using the comprehensive performance evaluation index S, specifically as follows: If S≥0.85, the comprehensive performance of the improved coarse-grained saline soil is excellent. If 0.70≤S<0.85, then the comprehensive performance of the improved coarse-grained saline soil is good. If 0.50≤S<0.70, then the overall performance of the improved coarse-grained saline soil is moderate. If S < 0.50, the overall performance of the improved coarse-grained saline soil is inferior.

3. The method for evaluating the comprehensive performance of improved coarse-grained saline soil according to claim 1, characterized in that, In S3, In the formula, S is a comprehensive performance evaluation index, which is dimensionless; These are mechanical property parameters, dimensionless. The weights for mechanical properties are dimensionless. This is a dimensionless parameter representing volume stability. The weight for volume stability is dimensionless; These are microstructural characteristic parameters, which are dimensionless. The weights are for the microstructural features.

4. The method for evaluating the comprehensive performance of improved coarse-grained saline soil according to claim 1 or 3, characterized in that, The mechanical performance parameters It is determined based on the cohesion, internal friction angle, and compressive strength of the improved coarse-grained saline soil specimen. The volume stability parameters It was determined based on the salt swelling amount and the solution collapse coefficient of the improved coarse-grained saline soil specimen. The microstructure characteristic parameters It was determined based on the porosity and Ca / Si ratio of the improved coarse-grained saline soil specimen.

5. The method for evaluating the comprehensive performance of improved coarse-grained saline soil according to claim 4, characterized in that, The mechanical performance parameters It is determined according to the following formula: In the formula, The cohesion of the improved coarse-grained saline soil specimen is expressed in kPa. The cohesion of the plain soil is expressed in kPa. The percentage of cohesive force is dimensionless. The internal friction angle of the improved coarse-grained saline soil specimen, in degrees; The internal friction angle of the plain soil, in degrees; This represents the proportion of the internal friction angle, which is dimensionless. The compressive strength of the improved coarse-grained saline soil specimen is given in MPa. The compressive strength of the unpaved soil, in MPa; This represents the proportion of compressive strength, dimensionless.

6. The method for evaluating the comprehensive performance of improved coarse-grained saline soil according to claim 5, characterized in that, The volume stability parameters It is determined according to the following formula: In the formula, Salt swelling of the improved coarse-grained saline soil specimen, unit: mm; Salt swelling of the soil, unit: mm; The percentage of salt swelling is dimensionless. The solution collapse coefficient of the improved coarse-grained saline soil specimen is dimensionless. is the solution collapse coefficient of the plain soil, dimensionless; This represents the proportion of the dissolution coefficient, which is dimensionless.

7. The method for evaluating the comprehensive performance of improved coarse-grained saline soil according to claim 6, characterized in that, The microstructure characteristic parameters It is determined according to the following formula: In the formula, The porosity of the improved coarse-grained saline soil specimen is dimensionless. The porosity of the raw soil is dimensionless. Porosity percentage, dimensionless; The Ca / Si ratio of the improved coarse-grained saline soil specimen is dimensionless. The Ca / Si ratio of the raw soil is dimensionless. The Ca / Si ratio is dimensionless.

8. The method for evaluating the comprehensive performance of improved coarse-grained saline soil according to claim 7, characterized in that, The weight of the mechanical properties Weights for volume stability Weights of microstructural features It is determined based on the eigenvector method; The proportion of cohesion Internal friction angle ratio and compressive strength ratio It is determined based on the eigenvector method; The proportion of salt swelling and salt swelling ratio It is determined based on the eigenvector method; porosity percentage and Ca / Si ratio It is determined based on the eigenvector method.

9. The method for evaluating the comprehensive performance of improved coarse-grained saline soil according to claim 1, characterized in that, In S1, the modified material is formed by mixing rice husk ash, fiber and cement in a mass ratio of 15-25:0.1-0.5:6-10.

10. The method for evaluating the comprehensive performance of improved coarse-grained saline soil according to claim 9, characterized in that, The fiber is basalt fiber.

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