A method for analyzing influence of soil pore structure based on W-OH spraying

Abstract

The present application relates to a kind of soil pore structure influence analysis method based on W-OH spraying, based on the spraying test of each concentration W-OH proportioning solution including 0% concentration to target soil sample respectively, by CT scanning and image processing, the porosity curve under each concentration W-OH proportioning solution is constructed, and along the direction of soil depth, the first intersection position of the porosity curve of 0% concentration W-OH proportioning solution and the porosity curve of the rest each concentration W-OH proportioning solution is determined, to form the consolidation depth of each concentration W-OH proportioning solution greater than 0% concentration with the soil depth of each intersection position, accurately, quickly realize the quantitative analysis of consolidation depth, and present the change of pore structure with soil depth, for the concentration screening of W-OH in soil erosion prevention practice, application effect prediction, provide standardized, reproducible scientific guidance basis and data basis, improve the objectivity and accuracy of soil structure analysis under W-OH application.

Description

Technical Field

[0001] This invention relates to a method for analyzing the impact of W-OH spraying on soil pore structure, belonging to the field of soil solidification analysis technology. Background Technology

[0002] Current research on erosion problems in sloping farmland and landslide-prone areas mainly focuses on the intensity, process, mechanism, and prevention and control measures of soil erosion, providing a solid theoretical foundation for the prevention and control of erosion in these two typical soil types. Traditional prevention and control measures mainly include biological measures, engineering measures, and tillage measures. Biological measures include afforestation, grass planting, and enclosure, which reduce erosion and stabilize soil through plant growth. Specifically, this includes using root systems to wrap around soil particles to fix the soil, using canopies to intercept rainfall and reduce rainfall erosion, and improving the soil's resistance to erosion by improving the soil environment. Engineering measures include terraces, horizontal ditches, and ditch head protection, which modify the micro-topography to store rainwater on-site, increase soil moisture to supply crops or vegetation growth, and prevent soil erosion on slopes. Tillage measures include contour farming and reduced / no-till farming, which artificially adjust the micro-topography to intercept runoff, increase ground cover, promote water infiltration, and reduce slope runoff erosion. After decades of management, the overall control of soil erosion in sloping farmland and landslide-prone areas has achieved certain results. However, sloping farmland is mostly cultivated in the spring, overlapping with seasonal rainfall, leading to widespread erosion. Rapid soil stabilization is needed before crops can establish themselves and stabilize the soil. Furthermore, to promote rapid vegetation growth, landslide control efforts are also concentrated in the spring, but seasonal rainfall can exacerbate landslide erosion caused by engineering measures. Therefore, rapid and effective soil stabilization is necessary before vegetation can establish itself and stabilize the soil. Phased, rapid soil stabilization measures based on environmentally friendly chemical materials become a suitable option.

[0003] Hydrophilic polyurethane (W-OH) is a water-based liquid polymer material that, when mixed with water and sprayed onto surface soil, rapidly forms an elastic, porous, consolidated layer. This quickly reduces soil erosion intensity, achieving efficient soil stabilization in a short period. It boasts advantages such as environmental friendliness, stable performance, and non-polluting natural degradation. It has been widely applied and has achieved significant results in desertification control, sandstone remediation, alpine meadow ecological restoration, riverbank slope management in sandy areas, sloping farmland control, and ridge collapse management. Although existing research has revealed the anti-erosion mechanism of W-OH from the perspectives of consolidated layer performance, consolidation process, and chemical solidification principles, some key issues remain to be addressed. For example, the consolidation depth of W-OH in red soil areas is unclear, and the porosity characteristics of the consolidated layer are not yet fully understood. This has resulted in the current theoretical framework for W-OH in soil erosion control lagging behind practical application, limiting further improvements in W-OH's effectiveness and its wider application in soil erosion control. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a method for analyzing the impact of W-OH spraying on soil pore structure. By using CT tomography technology, this invention explores the effects of hydrophilic polyurethane on soil consolidation depth and soil structure, providing guidance and basis for the application of W-OH in soil erosion control.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The present invention designs a method for analyzing the influence of W-OH spraying on soil pore structure, and performs the following steps A to D to obtain the consolidation depth analysis of W-OH spraying on the target soil;

[0006] Step A. Prepare W-OH solutions of various preset concentrations, including 0% concentration, and create target soil samples of preset heights corresponding to each W-OH solution of various concentrations. Spray each W-OH solution of various concentrations onto the surface of the corresponding target soil sample, and then proceed to Step B.

[0007] Step B. For each W-OH solution of different concentrations, obtain the corresponding preset number of tomographic images of the target soil sample by CT scanning, and determine the tomographic image representing the soil surface as the first tomographic image. Obtain tomographic images corresponding to the preset soil depth from the first tomographic image to form the tomographic image set corresponding to the W-OH solution of different concentrations, and then proceed to step C.

[0008] Step C. For each W-OH solution of different concentrations, obtain the porosity values ​​corresponding to each tomographic scan image in the corresponding tomographic image set. Based on the porosity coordinate system with porosity on the horizontal axis and soil depth on the vertical axis, mark the location of each porosity value and connect them to obtain the porosity curve corresponding to the W-OH solution of different concentrations. Then proceed to step D.

[0009] Step D. Based on the porosity curves corresponding to each concentration of W-OH solution in the same porosity coordinate system, from the vertical axis 0 to the soil depth direction, obtain the first intersection point of the porosity curve corresponding to the 0% concentration W-OH solution with the porosity curves corresponding to the other concentrations of W-OH solutions. Take the soil depth corresponding to each intersection point as the consolidation depth corresponding to the other concentrations of W-OH solution, that is, obtain the consolidation depth of each preset concentration of W-OH solution with respect to the target soil for concentrations greater than 0%.

[0010] As a preferred technical solution of the present invention: In step A, after each concentration of W-OH solution is sprayed onto the surface of the corresponding target soil sample, each target soil sample is left to stand for a preset time, and then wrapped with plastic wrap to fix and protect for a preset time before proceeding to step B.

[0011] As a preferred technical solution of the present invention: In step B, based on the target difference between the area ratio of the gray region corresponding to soil particles and the area ratio of the black region corresponding to air in the tomographic scan image, for each concentration of W-OH solution, based on the tomographic scan images of the corresponding target soil sample from top to bottom, the first tomographic scan image with a target difference less than a preset threshold is determined, thus constituting the tomographic scan image representing the soil surface corresponding to the concentration of W-OH solution.

[0012] As a preferred technical solution of the present invention: In step C, for each W-OH solution of different concentrations, median filtering and image enhancement processing are performed on each tomographic scan image in the corresponding tomographic image set. After obtaining the grayscale histogram and combining it with the preset grayscale threshold, the soil structure binarized image of each tomographic scan image is obtained, and then the porosity value corresponding to each tomographic scan image is obtained.

[0013] As a preferred technical solution of the present invention: In step C, while obtaining the porosity curve corresponding to each concentration of W-OH solution, the method also includes obtaining the pore quantity value, pore roundness value, and average equivalent pore diameter value corresponding to each tomographic scan image in the corresponding tomographic image set, and performing the following:

[0014] Based on a pore number coordinate system with the horizontal axis representing the number of pores and the vertical axis representing the soil depth, the location of each pore number value is marked and connected to obtain the pore number curve corresponding to the concentration of W-OH solution.

[0015] Based on a pore roundness coordinate system with the horizontal axis representing pore roundness and the vertical axis representing soil depth, the positions of each pore roundness value are marked and connected to obtain the pore roundness curve corresponding to the concentration W-OH solution.

[0016] Based on the average equivalent pore size coordinate system with the horizontal axis representing the average equivalent pore size and the vertical axis representing the soil depth, the positions of each average equivalent pore size value are marked and connected to obtain the average equivalent pore size curve corresponding to the concentration W-OH ratio solution.

[0017] In step D, based on the consolidation depth of the target soil with respect to the preset concentrations of W-OH solutions with a concentration greater than 0%, further for each concentration of W-OH solution with a concentration greater than 0%, obtain the pore quantity curve, pore roundness curve, and average equivalent pore diameter curve within the depth range from the soil surface to the corresponding consolidation depth, as well as the pore quantity curve, pore roundness curve, and average equivalent pore diameter curve within the depth range downward from the consolidation depth.

[0018] As a preferred technical solution of the present invention: In step C, while obtaining the porosity curve corresponding to each concentration of W-OH solution, the method also includes obtaining the fractal dimension, anisotropy, pore surface area, and pore connectivity density values ​​corresponding to each tomographic scan image in the corresponding tomographic image set, and performing the following:

[0019] Based on a fractal dimension coordinate system with fractal dimension on the horizontal axis and soil depth on the vertical axis, the positions of each fractal dimension value are marked and connected to obtain the fractal dimension curve corresponding to the concentration of W-OH solution.

[0020] Based on an anisotropic coordinate system with anisotropy on the horizontal axis and soil depth on the vertical axis, the positions of each anisotropic value are marked and connected to obtain the anisotropic curves corresponding to the concentration W-OH ratio solution.

[0021] Based on a pore surface area coordinate system with the horizontal axis representing pore surface area and the vertical axis representing soil depth, the location of each pore surface area value is marked and connected to obtain the pore surface area curve corresponding to the concentration W-OH ratio solution.

[0022] Based on a pore connectivity density coordinate system with the horizontal axis representing pore connectivity density and the vertical axis representing soil depth, the location of each pore connectivity density value is marked and connected to obtain the pore connectivity density curve corresponding to the concentration W-OH solution.

[0023] In step D, based on the consolidation depth of the target soil with respect to the preset concentrations of W-OH solutions with a concentration greater than 0%, the fractal dimension curve, anisotropy curve, pore surface area curve, and pore connectivity density curve are obtained for each concentration of W-OH solutions with a concentration greater than 0%, respectively, within the depth range from the soil surface to the corresponding consolidation depth. Additionally, the fractal dimension curve, anisotropy curve, pore surface area curve, and pore connectivity density curve are obtained within the depth range downward from the consolidation depth.

[0024] The method for analyzing the impact of W-OH spraying on soil pore structure described in this invention has the following technical advantages compared with existing technologies:

[0025] (1) This invention designs a method for analyzing the impact of W-OH spraying on soil pore structure. Based on the spraying test of W-OH solutions of various concentrations including 0% on the corresponding target soil samples, the porosity curves of W-OH solutions of various concentrations along the soil depth are constructed by CT scanning and image processing. Along the soil depth direction, the first intersection point of the porosity curve corresponding to the 0% concentration W-OH solution and the porosity curves corresponding to the other W-OH solutions is determined. Then, the soil depth at each intersection point is used to form the consolidation depth of W-OH solutions of various concentrations greater than 0%. The design scheme can not only accurately and quickly realize the quantitative analysis of consolidation depth, but also present the change of pore structure with soil depth. It provides a standardized and reproducible scientific guidance and data basis for concentration screening and application effect prediction of W-OH in soil erosion prevention and control practice, and significantly improves the objectivity and accuracy of soil structure analysis under W-OH application.

[0026] (2) The soil pore structure influence analysis method based on W-OH spraying designed in this invention utilizes the characteristic that the natural porosity of soil without W-OH spraying changes relatively slowly with depth. For the W-OH-affected layer (porosity significantly reduced) and the unaffected layer (porosity returns to the natural state), the method of objective quantification by curve intersection is designed, which significantly improves the accuracy, consistency and repeatability of consolidation depth determination, and makes the consolidation depth comparison results between different concentrations and different soil types more scientific and reliable.

[0027] (3) In the soil pore structure influence analysis method based on W-OH spraying designed in this invention, the number of pores, pore roundness rate, and average equivalent pore diameter are further analyzed. Based on the consolidation depth, the W-OH-affected layer (porosity significantly reduced) and the unaffected layer (porosity returns to natural state) are divided. The influence of W-OH consolidation on soil microstructure is revealed from multiple two-dimensional index perspectives. This provides rich quantitative indicators for a deeper understanding of the differences in the response of different soil textures to W-OH, and provides more comprehensive guidance for optimizing W-OH formulation and application process.

[0028] (4) The soil pore structure influence analysis method based on W-OH spraying designed in this invention goes beyond the traditional two-dimensional planar analysis. It analyzes the three-dimensional indicators of fractal dimension, anisotropy, pore surface area and pore connectivity density. Based on the consolidation depth, the W-OH-affected layer (porosity significantly reduced) and the unaffected layer (porosity returns to the natural state) are divided. The overall influence of the W-OH consolidation layer on the soil pore network structure is revealed from the three-dimensional spatial dimension. It provides key internal structural parameters for evaluating the erosion resistance and durability of the W-OH consolidation layer, and strongly supports its mechanism explanation as an efficient soil and water conservation material. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the results of median filtering and image enhancement processing of a tomographic image based on the soil pore structure influence analysis method designed in this invention, which is based on W-OH spraying.

[0030] Figure 2 This is a schematic diagram illustrating the effect of different concentrations of W-OH solutions in this invention on the porosity of two types of soil as a function of soil depth.

[0031] Figure 3 This is a schematic diagram showing the vertical distribution characteristics of various two-dimensional pore indices under different concentrations of W-OH in the design of this invention.

[0032] Figure 4 This is a schematic diagram of the three-dimensional structure of two types of soil under different concentrations of W-OH solutions in the design of this invention. Detailed Implementation

[0033] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0034] The present invention proposes a method for analyzing the impact of W-OH spraying on soil pore structure. The method involves performing the following steps A to D to obtain an analysis of the consolidation depth of the target soil by W-OH spraying.

[0035] Step A. Prepare W-OH solutions of various preset concentrations, including 0% concentration, and create target soil samples of preset heights corresponding to each W-OH solution of different concentrations. Spray each W-OH solution of different concentrations onto the surface of the corresponding target soil sample. After each target soil sample has been left to stand for a preset time, wrap it with plastic wrap to fix and protect it for a preset time. Then proceed to Step B.

[0036] Step B. For each W-OH solution of different concentrations, obtain a preset number of tomographic images corresponding to the target soil sample using CT scanning. Based on the target difference between the area ratio of the gray region corresponding to soil particles and the area ratio of the black region corresponding to air in the tomographic images, determine the first tomographic image with a target difference less than a preset threshold based on the sequential tomographic images of the target soil sample from top to bottom. This first tomographic image represents the soil surface corresponding to the W-OH solution of different concentrations and is used as the first tomographic image. Then, obtain tomographic images corresponding to a preset soil depth downwards from the first tomographic image to form a tomographic image set corresponding to the W-OH solution of different concentrations, and then proceed to Step C.

[0037] Step C. For each W-OH solution of different concentrations, perform median filtering and image enhancement processing on each tomographic scan image in the corresponding tomographic image set. Then, obtain the soil structure binarized image of each tomographic scan image by combining the grayscale histogram with the preset grayscale threshold, and then obtain the porosity value corresponding to each tomographic scan image. Then, based on the porosity coordinate system with porosity on the horizontal axis and soil depth on the vertical axis, mark the location of each porosity value and connect them to obtain the porosity curve corresponding to the W-OH solution of different concentrations, and then proceed to step D.

[0038] In practical applications, step C not only obtains the porosity curves corresponding to each concentration of W-OH solution according to the above design, but also designs soil structure binarized images based on each fault scan image in the corresponding fault image set for each concentration of W-OH solution, obtaining the pore quantity value, pore roundness value, and average equivalent pore diameter value corresponding to each fault scan image, and performs the following:

[0039] Based on a pore number coordinate system with the horizontal axis representing the number of pores and the vertical axis representing the soil depth, the location of each pore number value is marked and connected to obtain the pore number curve corresponding to the concentration of W-OH solution.

[0040] Based on a pore roundness coordinate system with the horizontal axis representing pore roundness and the vertical axis representing soil depth, the positions of each pore roundness value are marked and connected to obtain the pore roundness curve corresponding to the concentration W-OH solution.

[0041] Based on the average equivalent pore size coordinate system with the horizontal axis representing the average equivalent pore size and the vertical axis representing the soil depth, the positions of each average equivalent pore size value are marked and connected to obtain the average equivalent pore size curve corresponding to the concentration W-OH solution.

[0042] Then, the pore number curve, pore roundness curve, and average equivalent pore diameter curve corresponding to W-OH solutions of different concentrations were obtained.

[0043] The porosity, pore number, pore sphericity, and average equivalent pore diameter mentioned above are all two-dimensional indicators. In practical applications, three-dimensional indicators can also be analyzed, including fractal dimension, anisotropy, pore surface area, and pore connectivity density. Specifically, for W-OH solutions of various concentrations, binarized soil structure images based on tomographic scan images from corresponding tomographic image sets are designed to obtain the fractal dimension, anisotropy, pore surface area, and pore connectivity density values ​​corresponding to each tomographic scan image, and then the following steps are performed:

[0044] Based on a fractal dimension coordinate system with fractal dimension on the horizontal axis and soil depth on the vertical axis, the positions of each fractal dimension value are marked and connected to obtain the fractal dimension curve corresponding to the concentration of W-OH solution.

[0045] Based on an anisotropic coordinate system with anisotropy on the horizontal axis and soil depth on the vertical axis, the positions of each anisotropic value are marked and connected to obtain the anisotropic curves corresponding to the concentration W-OH ratio solution.

[0046] Based on a pore surface area coordinate system with the horizontal axis representing pore surface area and the vertical axis representing soil depth, the location of each pore surface area value is marked and connected to obtain the pore surface area curve corresponding to the concentration W-OH ratio solution.

[0047] Based on a pore connectivity density coordinate system with the horizontal axis representing pore connectivity density and the vertical axis representing soil depth, the locations of each pore connectivity density value are marked and connected to obtain the pore connectivity density curve corresponding to the concentration of W-OH solution.

[0048] Then, the fractal dimension curve, anisotropy curve, pore surface area curve, and pore connectivity density curve corresponding to W-OH solutions of different concentrations were obtained.

[0049] According to the above design, in practical applications, the overall impact of the W-OH consolidation layer on the soil pore network structure can be revealed from two-dimensional and three-dimensional spatial dimensions.

[0050] Step D. Based on the porosity curves corresponding to each concentration of W-OH solution in the same porosity coordinate system, from the vertical axis 0 to the soil depth direction, obtain the first intersection point of the porosity curve corresponding to the 0% concentration W-OH solution with the porosity curves corresponding to the other concentrations of W-OH solutions. Take the soil depth corresponding to each intersection point as the consolidation depth corresponding to the other concentrations of W-OH solution, that is, obtain the consolidation depth of each preset concentration of W-OH solution with respect to the target soil for concentrations greater than 0%.

[0051] Further connecting with the analysis of the two-dimensional indices of pore quantity, pore roundness, and average equivalent pore diameter in step C above, step D is further designed. Specifically, based on preset W-OH solutions with concentrations greater than 0% and varying consolidation depths in the target soil, pore quantity curves, pore roundness curves, and average equivalent pore diameter curves are obtained for each W-OH solution concentration greater than 0% within the depth range from the soil surface to the corresponding consolidation depth, as well as for the pore quantity curves, pore roundness curves, and average equivalent pore diameter curves within the depth range downwards from the consolidation depth.

[0052] Similarly, in connection with the analysis of the three-dimensional indices of fractal dimension, anisotropy, pore surface area, and pore connectivity density in step C above, further design is carried out for step D. That is, based on the consolidation depth of the target soil with preset W-OH solutions of each concentration greater than 0%, fractal dimension curves, anisotropy curves, pore surface area curves, and pore connectivity density curves are obtained for each W-OH solution of each concentration greater than 0%, within the depth interval from the soil surface to the corresponding consolidation depth, as well as fractal dimension curves, anisotropy curves, pore surface area curves, and pore connectivity density curves within the depth interval from the consolidation depth downwards.

[0053] Applying the above design scheme to practice, the specific target soil was selected at the Yingtan Red Soil Ecological Experimental Station of the Chinese Academy of Sciences. Quaternary red clay red soil (QRC) and Ganxian District, Ganzhou City, Jiangxi Province, China Granitic red soil (GRS).

[0054] The Yingtan Red Soil Ecological Experimental Station of the Chinese Academy of Sciences is located in Yujiang District, Yingtan City, Jiangxi Province. It has a subtropical monsoon climate with an average annual temperature of 18.4℃ and annual precipitation of approximately 1800 mm, mainly concentrated in April to June. The terrain is primarily low hills and gentle slopes with gradients ranging from 3° to 15°. Land use types mainly include secondary forest, sloping farmland, and orchards, with sloping farmland covering an area of ​​245.44 km². 2 The parent material of the soil in the study area is Quaternary red clay, and the soil is typical red soil from the Quaternary red clay region. It is heavy, poorly aerated, and poorly permeable, easily forming surface runoff during rainfall, causing severe soil erosion. Ganxian District, Ganzhou City, Jiangxi Province, China, has a humid mid-subtropical monsoon climate with an average annual temperature of 19.6℃ and an average annual rainfall of 1476 mm, which is unevenly distributed throughout the year, with about 50% of the rainfall occurring from April to July. The terrain of this area is mainly hilly, with an altitude of 500-1000 meters and steep slopes. Red-brown soil developed from granite is widely distributed, containing a large amount of quartz sand and gravel. The soil texture is relatively coarse, leading to severe leaching of water and fertilizer. Ridge collapse is a typical erosion pattern in this area.

[0055] Due to different soil-forming conditions, Quaternary red clay soil (QRC) and granitic red soil (GRS) exhibit significant differences in properties. QRC is characterized by a relatively uniform distribution of sand, silt, and clay particles, with each particle size accounting for approximately one-third of the total composition. In contrast, GRS has a higher proportion of sand, accounting for about two-thirds of the total composition, with the remaining one-third consisting of silt and clay particles. Other physical and chemical properties of the two soils, i.e., basic physicochemical properties, are shown in Table 1 below.

[0056] Table 1 Basic physicochemical properties of QRC and GRS

[0057]

[0058] In practical application, the aforementioned Quaternary red clay soil (QRC) and granitic red soil (GRS) were used as target soils, and the designed steps A to D were executed.

[0059] In step A, W-OH solutions of 0%, 0.5%, 1%, and 2% concentrations are prepared, and target soil samples of preset heights are created corresponding to each W-OH solution. Each target soil sample is filled into a PVC ring cutter with a height of 5 cm and a diameter of 5 cm. To ensure the uniformity of soil filling, the soil is lightly compacted. Then, each W-OH solution is sprayed onto the surface of the corresponding target soil sample. After each target soil sample is left to stand for a preset time, it is wrapped with plastic wrap to fix and protect it for a preset time before proceeding to step B.

[0060] Next, step B is performed, which involves scanning the corresponding target soil samples using industrial X-ray CT for each concentration of W-OH solution, obtaining 2200-2300 tomographic images with a resolution of 25 μm. Before extracting soil porosity indices, the region of interest (ROI) needs to be determined. Since the image of the upper part of the soil column includes the overlying plastic wrap, the ring cover, and the voids between the topsoil, the first tomographic image representing the soil surface needs to be selected. This is based on the target difference between the proportion of gray areas corresponding to soil particles and the proportion of black areas corresponding to air in the tomographic image. Based on the sequential tomographic images of the target soil sample from top to bottom, the first tomographic image with a target difference less than a preset threshold is selected, forming the tomographic image representing the soil surface corresponding to the concentration of W-OH solution. This is used as the first tomographic image. Considering the edge effect at the bottom of the ring, the bottom 1 cm thickness is generally removed to eliminate the influence. Therefore, the tomographic images corresponding to the preset soil depth (ROI) from the first to the next lower level are obtained. In this application, for example, 1600 images (0-4) are selected. The tomographic images (cm) are used to form a set of tomographic images corresponding to the concentration of W-OH solution, and then proceed to step C.

[0061] Then, step C is executed. In this application, for each W-OH solution with different concentrations and ratios, the corresponding tomographic images from the tomographic image set are imported into ImageJ software. Median filtering and image enhancement are then performed on each tomographic image. The processing results are as follows: Figure 1As shown in the image, the large areas of white and scattered grayish-white represent the soil solid phase, the grayish-black represents the soil pores, and the uniform grayish-white represents the W-OH solidified body. The W-OH solidified body is similar in color to the soil solid phase, and its distribution cannot be accurately determined solely by color. Considering that the target soil sample is a sieved and uniformly packed soil, theoretically, soil particles and pores are evenly distributed from top to bottom. By comparing the unfilled pores in the W-OH infiltration layer with the uninfiltrated pores at the bottom, the W-OH infiltration depth and changes in the soil structure of the infiltration layer can be determined. ImageJ software further utilizes grayscale histograms and preset grayscale thresholds to perform threshold segmentation on each tomographic scan image, obtaining a binary image of the soil structure for each tomographic scan image. Porosity indices, i.e., the porosity values ​​corresponding to each tomographic scan image, are then extracted from ImageJ. The software outputs J; then, based on a porosity coordinate system with porosity on the horizontal axis and soil depth on the vertical axis, it marks the location of each porosity value and connects them to obtain the porosity curve corresponding to the concentration W-OH solution, and then proceeds to step D.

[0062] According to the design of this invention, step C not only obtains the porosity values ​​of each tomographic scan image, but also extracts two-dimensional indices such as pore quantity, pore roundness, and average equivalent pore diameter using ImageJ software. Furthermore, it uses the BoneJ plugin in ImageJ software to analyze four three-dimensional porosity indices: fractal dimension, anisotropy, pore surface area, and pore connectivity density. This results in obtaining fractal dimension curves, anisotropy curves, pore surface area curves, and pore connectivity density curves corresponding to W-OH solutions of different concentrations.

[0063] Porosity refers to the percentage of the pore area of ​​a soil cross-section to the total area of ​​that cross-section. Its value can reflect the structural characteristics of the soil to a certain extent. The calculation formula is as follows: ,in, Indicates soil porosity (%) This represents the area of ​​the selected region of interest, which is 900 mm in the design and application of this invention. 2 , This represents the pore area (mm²) within the region of interest. 2 ).

[0064] Pore ​​roundness ratio refers to the degree to which the shape of soil pores closely resembles a standard circle. It represents the morphological characteristics of irregular pores. The closer the value is to 1, the closer the pore structure is to a standard circle; the closer the value is to 0, the more irregular the pore shape. The calculation formula is as follows: ,in, Represents the circumstancy rate. Indicates the circumference of the pore (mm).

[0065] The average equivalent pore size refers to the average pore size equivalent to a certain soil water suction. It can intuitively reflect the overall trend of pore size changes. The calculation formula is as follows: ,in, This represents the average equivalent pore diameter (mm). Indicates the number of pores.

[0066] Regarding three-dimensional indicators, fractal dimension reflects the effectiveness of an object in occupying space and is a measure of the irregularity of complex shapes. Fractal dimension values ​​range from 2 to 3, with higher values ​​indicating larger and more regular pores. Anisotropy, also known as "non-homogeneity," refers to the degree to which an object's properties change with direction. It is used to measure whether the spatial distribution of pores follows a clear trend. Studying its value can reflect whether the spatial distribution of porosity has a certain trend of change. Anisotropy values ​​range from 0 to 1, with higher values ​​indicating a more obvious spatial trend and pore distribution. Pore surface area and connectivity density reflect the number, size, and internal connectivity of pores. Higher values ​​indicate relatively larger pores, a greater number of pores, and better connectivity.

[0067] Porosity refers to the ratio of pore volume to total volume. It is a key factor affecting the way water moves on the soil surface and inside the soil. It has a direct impact on the consolidation, distribution and retention of soil moisture. When W-OH is sprayed on the soil surface, it can consolidate in a short time, bind to the soil and adhere to the surface of soil particles, forming a relatively obvious film or filamentous cement in the pores, greatly reducing pores and significantly changing the porosity of the soil.

[0068] like Figure 2 As shown, the effect of different concentrations of W-OH solutions on the porosity of two soil types (QRC and GRS) with soil depth is illustrated. Under the condition of no W-OH spraying, the porosity of the soil sample is slightly increased from top to bottom because the soil sample is a sieved and uniformly packed soil, but the overall change is small. After W-OH spraying, the porosity of the top layer of soil is significantly smaller than that of the soil sample without W-OH spraying. With the increase of depth, the porosity of the soil sample sprayed with W-OH gradually approaches that of the soil sample without W-OH spraying, and coincides with the porosity curve of the soil sample at the bottom layer. That is, the depth at which they first coincide can be regarded as the consolidation depth of W-OH. For QRC soils, the porosity of soil samples sprayed with 0.5% and 1% W-OH was significantly lower than that of unsprayed soil samples in the 0–2 cm depth, while at 2 cm, the porosity curves began to overlap with those of unsprayed W-OH soil samples. Similarly, the porosity of soil samples sprayed with 2% W-OH was significantly lower than that of unsprayed soil samples in the 0–1 cm depth, but at 1 cm, it began to overlap with those of unsprayed W-OH soil samples. Therefore, for QRC soils, 0–2 cm can be considered the consolidation depth for soil samples sprayed with 0.5% and 1% W-OH, and 0–1 cm can be considered the consolidation depth for soil samples sprayed with 2% W-OH.

[0069] Similarly, regarding the porosity curves of unsprayed GRS soil samples, the porosity of soil samples sprayed with 0.5% W-OH was significantly lower than that of unsprayed soil samples in the 0-3 cm range, and began to overlap with that of unsprayed soil samples at 3 cm. Similarly, the porosity of soil samples sprayed with 1% W-OH was significantly lower than that of unsprayed soil samples in the 0-2 cm range, and began to overlap with that of unsprayed soil samples at 2 cm. Furthermore, the porosity of soil samples sprayed with 2% W-OH was significantly lower than that of unsprayed soil samples in the 0-1.5 cm range, and began to overlap with that of unsprayed soil samples at 1.5 cm. Therefore, it can be determined that 0-3 cm represents the consolidation depth of soil samples sprayed with 0.5% W-OH, 0-2 cm represents the consolidation depth of soil samples sprayed with 1% W-OH, and 0-1.5 cm represents the consolidation depth of soil samples sprayed with 2% W-OH.

[0070] Finally, step D is performed to obtain the consolidation depth of the target soil for each preset concentration of W-OH solution with a concentration greater than 0%.

[0071] In applications, QRC soil exhibits a shallower consolidation depth at the same W-OH concentration compared to GRS soil. This is primarily attributed to the differences in texture, structure, and soil-forming processes between the two soil types. GRS soil is mainly composed of weathered granite products, with its mineral composition dominated by quartz, feldspar, and mica. Its coarser particles and larger pores facilitate rapid water infiltration. In contrast, QRC soil is rich in quartz and clay minerals (such as kaolinite and montmorillonite), with a significantly higher clay content than GRS soil. Its smaller pores significantly increase resistance to water flow. Furthermore, QRC soil underwent intense desilication and iron-aluminum enrichment during its formation, resulting in higher iron and aluminum oxide content and relatively more organic matter accumulation. These characteristics cause W-OH solution to flow slowly and consolidate at a shallower depth in QRC soil. Therefore, in contrast, the lower clay content and larger pore structure of GRS soil make it more permeable, leading to a greater consolidation depth of W-OH solution.

[0072] Based on the consolidation depth of the target soil for each preset concentration of W-OH solutions with a concentration greater than 0%, step D further analyzes the two-dimensional indices corresponding to each concentration of W-OH solutions, such as the number of pores, pore sphericity, and average equivalent pore size. Figure 3As shown, the vertical distribution characteristics of various two-dimensional indices of porosity under different concentrations of W-OH solutions are illustrated. For QRC soil, the porosity of untreated soil shows little change with depth, increasing slightly from top to bottom. The porosity of W-OH treated soil increases with depth in the consolidated layer, with the increase positively correlated with W-OH concentration, and then fluctuates steadily after entering the undisturbed layer. The number of pores varies between different concentrations. The number of untreated pores increases rapidly from 0 to 0.3 cm, then decreases to its lowest point from 0.3 to 0.6 cm, and then fluctuates continuously. The number of treated pores increases rapidly from 0 to 0.5 cm, then decreases from 0.5 to 1 cm, and then fluctuates continuously. The sphericity changes in the opposite direction to porosity. The sphericity of untreated soil decreases slightly from top to bottom, with little overall change. The sphericity of W-OH treated soil decreases with depth in the consolidated layer, with the decrease increasing with increasing concentration, and then fluctuates steadily after entering the undisturbed layer. The variation trend of the average equivalent diameter is similar to that of porosity, showing an increasing trend with increasing depth. The increase is greater with increasing concentration, reflecting the enhanced heterogeneity of soil pore size distribution.

[0073] For GRS soils, the porosity of untreated W-OH increased slightly from top to bottom, with little overall change. The porosity of W-OH treated soils increased with depth in the consolidated layer, with the increase in magnitude increasing with concentration, and remained stable after entering the undisturbed layer. The number of pores varied with different concentrations. The number of pores in untreated soils remained stable in the 0–3 cm range, decreasing in the 3–4 cm range. The number of pores in 0.5% W-OH treated soils initially increased and then decreased in the consolidated layer, decreasing further after entering the undisturbed layer. The number of pores in 1% and 2% W-OH treated soils fluctuated in the consolidated layer and showed a fluctuating decreasing trend in the undisturbed layer. The sphericity trend was opposite to that of porosity. The sphericity of untreated soils decreased slightly from top to bottom, with little overall change. The sphericity of W-OH treated soils decreased with depth in the consolidated layer, maintaining stable fluctuations after entering the undisturbed layer. The average equivalent diameter and porosity showed similar trends. The average equivalent pore size without W-OH treatment fluctuated steadily from top to bottom. The average equivalent pore size of 0.5% and 1% W-OH treatment showed a continuous upward trend with increasing depth. The average equivalent pore size of 2% W-OH treatment showed an upward trend in the range of 0 to 1.8 cm, decreased and stabilized in the range of 1.8 to 3 cm, and showed an upward trend in the range of 3 to 4 cm.

[0074] In practical applications, spraying W-OH solutions of different concentrations significantly reduced the porosity of the consolidated soil, improved pore roundness, and reduced pore diameter. During the consolidation process, after spraying the W-OH solution, the solidifying material bonded to the soil, adhering to the surface of soil particles, and rapidly formed a uniform gel-like coating layer. This layer fully covered most of the particles, filled the large pores in the soil, reduced soil porosity, and formed a distinct film or filamentous cement within the pores. Furthermore, the hydrophilic groups (such as hydroxyl groups) in W-OH can form hydrogen bonds with the hydroxyl groups on the surface of soil particles, enhancing the binding force between soil particles and making them more tightly bound together, forming larger aggregates and reducing pore diameter. Simultaneously, the characteristics of the polyurethane molecular structure enable it to fill the small pores in the soil, making the pore shape more regular and rounded, thus improving pore roundness.

[0075] In practical applications, to further characterize the effects of W-OH spraying on the two-dimensional porosity indices of QRC and GRS, based on the statistical analysis of the two-dimensional porosity indices of the consolidated layer and the bottom undisturbed layer of QRC and GRS with different W-OH concentrations shown in Table 2, the mean values ​​of porosity, number of pores, roundness, and average equivalent pore diameter of the two soil consolidation and undisturbed layers were calculated and analyzed by one-way ANOVA.

[0076] Table 2. Statistical analysis of two-dimensional porosity indices of QRC and GRS consolidated layers and bottom undisturbed layers with different W-OH concentrations.

[0077]

[0078] The results showed that W-OH treatment significantly altered the two-dimensional pore characteristics of the consolidated layers in both soil types (p<0.05). For QRC soil, the mean porosity of the four W-OH concentrations ranged from 9.78% to 19.71%. Compared with the undisturbed layer, the 0.5%, 1%, and 2% W-OH treatments significantly reduced the porosity of the consolidated layer (p<0.05), with reductions of 41.4%, 29.3%, and 44.8%, respectively. The mean number of pores ranged from 3226 to 5062. The 0.5%, 1%, and 2% W-OH treatments significantly reduced the number of pores in the consolidated layer (p<0.05), with reductions of 6.6%, 16.6%, and 9.3%, respectively. The mean roundness of the consolidation layer ranged from 0.7838 to 0.8568. Treatments with 0.5%, 1%, and 2% W-OH significantly increased the roundness of the consolidation layer (p<0.05), with increases of 7.2%, 3.5%, and 5.3%, respectively. The mean equivalent pore size ranged from 0.1755 to 0.2276 mm. Treatments with 0.5%, 1%, and 2% W-OH significantly reduced the equivalent pore size of the consolidation layer (p<0.05), with reductions of 22.6%, 9.2%, and 20.8%, respectively.

[0079] For GRS soils, the mean porosity of the four W-OH solutions ranged from 8.01% to 17.93%. Compared with the undisturbed layer, the 0.5%, 1%, and 2% W-OH treatments significantly reduced the porosity of the consolidated layer (p<0.05), with reductions of 53.5%, 49.9%, and 46.0%, respectively. The mean number of pores ranged from 2817 to 4629. The 0.5%, 1%, and 2% W-OH treatments significantly increased the number of pores in the consolidated layer (p<0.05), with increases of 21.4%, 0.3%, and 15.7%, respectively. The mean sphericity ranged from 0.7922 to 0.8608. The 0.5%, 1%, and 2% W-OH treatments significantly increased the sphericity of the consolidated layer (p<0.05), with increases of 7.2%, 6.2%, and 7.6%, respectively. The mean value of the average equivalent pore size ranged from 0.1488 to 0.2634 mm. Treatment with 0.5%, 1%, and 2% W-OH significantly reduced the average equivalent pore size of the consolidated layer (p<0.05), with reductions of 12.5%, 29.9%, and 34.5%, respectively.

[0080] After W-OH application, the number of pores in the consolidated layer of QRC soil was significantly less than that in the undisturbed layer (p<0.05), while the number of pores in the consolidated layer of GRS soil was significantly greater than that in the undisturbed layer (p<0.05). This difference may be due to variations in the consolidation process of W-OH in different soil types. When filling pores, W-OH in QRC soil exhibits net pore filling due to its higher clay content, denser natural micropores, and lower permeability, resulting in a decrease in the number of pores. In contrast, GRS soil has more sand particles, a looser structure, and more large pores, leading to a "consolidation-fragmentation" process in W-OH, where it fills large pores while simultaneously reconstructing them into more small pores, thus increasing the total number of pores.

[0081] In further practical applications, the ImageJ-processed data was reconstructed in Avizo to more intuitively demonstrate the effects of different concentrations of W-OH solution on the morphology, connectivity, and distribution characteristics of QRC and GRS soil pores. The three-dimensional structures of QRC and GRS under different concentrations of W-OH solution are shown below. Figure 4As shown, the blue areas represent soil pores, and the gray areas represent non-porous regions. The QRC and GRS soils without W-OH solution treatment exhibit typical porous characteristics, with numerous pores, some of which are interconnected, while the non-porous regions are scattered and small in area. The soil treated with W-OH solution shows a significant increase in non-porous regions, which are more uniformly connected, indicating the formation of a dense consolidation layer on the soil surface. With increasing W-OH concentration, the density and continuity of the consolidation layer show a gradient increase. Notably, with increasing soil depth, the continuity of the non-porous regions gradually weakens, changing from a uniform, continuous distribution to a dispersed patchy distribution. In the undisturbed layer, its distribution characteristics are essentially consistent with the untreated soil. This result indicates that W-OH solution effectively promotes the formation of a consolidation layer on the soil surface, and its effect gradually weakens with increasing depth.

[0082] The analysis of two-dimensional indices such as fractal dimension, anisotropy, pore surface area, and pore connectivity density reveals the impact of W-OH consolidation on soil microstructure from multiple two-dimensional perspectives. It provides a wealth of quantitative indicators for a deeper understanding of the differences in the response of different soil textures to W-OH, and offers more comprehensive guidance for optimizing W-OH formulations and application processes.

[0083] Further analysis was conducted on the fractal dimension, anisotropy, pore surface area, and pore connectivity density of the consolidated and undisturbed layers of the two soil types (QRC and GRS), as shown in Table 3.

[0084] Table 3. Three-dimensional porosity indices of soils with different concentrations of W-OH in the consolidated layer and the bottom undisturbed layer.

[0085]

[0086] For QRC soil samples, the fractal dimension of the consolidated layer after W-OH solution treatment ranged from 2.88 to 2.90, while that of the undisturbed layer ranged from 2.91 to 2.93, with no significant difference (p>0.05). The anisotropy of the consolidated layer after W-OH solution treatment ranged from 0.33 to 0.36, while that of the undisturbed layer was 0.33, with no significant difference (p>0.05). The pore surface area of ​​the consolidated layer after W-OH solution treatment ranged from 31398 to 65791 mm². 2 The undisturbed layer ranges from 91881 to 152281 mm. 2 Significant differences were observed among the treated soils (p<0.05). Compared to the undisturbed layer, the soils treated with 0.5%, 1%, and 2% W-OH showed reductions in the consolidated layer of 35.2%, 28.4%, and 79.4%, respectively. The pore connectivity density of the consolidated layer after W-OH solution treatment ranged from 13.23 to 37.88 mm. -3Significant differences also existed between the consolidated and undisturbed layers (p<0.05). Compared with the undisturbed layer, the 0.5%, 1%, and 2% soil samples showed reductions of 58.5%, 53.6%, and 60.6% in the consolidated layer, respectively.

[0087] For GRS soil samples, the fractal dimensions of the consolidated and undisturbed layers after spraying with W-OH solution ranged from 2.85 to 2.92, with little overall variation. Anisotropy ranged from 0.33 to 0.35, also with little overall variation; pore surface area ranged from 32338 to 97744 mm². 2 Significant differences existed between the consolidated and undisturbed layers (p<0.05). Compared to the undisturbed layer, soil samples with 0.5%, 1%, and 2% pore sizes increased by 77.26%, decreased by 36.6%, and decreased by 66.9% in the consolidated layer, respectively. Pore connectivity density ranged from 13.23 to 14.91 mm. -3 The undisturbed layer ranges from 29.43 to 37.88 mm. -3 There were significant differences between the consolidated and undisturbed layers (p<0.05). Compared with the undisturbed layer, the soil concentrations of 0.5%, 1%, and 2% decreased by 64.6%, 54.9%, and 70.4% in the consolidated layer, respectively.

[0088] After spraying with W-OH solutions of different concentrations, the fractal dimensions of both the consolidated and undisturbed layers of QRC and GRS soils were around 2.9, indicating a highly regular and complex soil structure. This is mainly because the test soil samples were sieved and uniformly packed, resulting in a high degree of self-similarity in the initial structure. No significant difference was found in the fractal dimension between the consolidated and undisturbed layers (p>0.05), indicating that the W-OH solutions completely preserved the original fractal characteristics of the soil during consolidation, achieving good structural continuity. The anisotropy of both soil types was around 0.35, indicating moderate directional anisotropy in the soil pore structure, with better horizontal pore connectivity than vertical connectivity. No significant difference was found in the anisotropy between the consolidated and undisturbed layers (p>0.05), indicating that the W-OH solutions effectively maintained the original anisotropic characteristics of the soil during consolidation. The main reason why the fractal dimension and anisotropy did not change significantly may lie in the mechanism of action of the W-OH solution. The hydrophilic groups in the W-OH solution molecular chain mainly adhere to the surface of soil particles through physical adsorption, rather than changing the surface properties of soil particles through chemical bonds (such as covalent or ionic bonds). Compared with traditional chemical amendments (such as PAM, EN-1, etc.), the physical consolidation of the W-OH solution causes less disturbance to the soil microstructure.

[0089] However, the soil pore surface area and pore connectivity density were significantly reduced (p<0.05), indicating that the W-OH solution solidified and filled part of the pores, reducing the connectivity between different pores. This may be due to the local aggregation of W-OH solution molecules within the pores, especially in smaller pores (<50 μm), where their hydrophilic groups cover the pore surface or fill the pore space through physical adsorption, thereby reducing the effective pore surface area and connectivity. From the perspective of anti-erosion mechanism, W-OH forms a network-like structural layer between soil particles through physical adsorption. This structural layer not only improves the cohesion between soil particles but also enhances the overall stability of the soil. Under the impact of water flow, this solidified layer can effectively resist the erosive effect of water flow.

[0090] The analysis of various three-dimensional indicators reveals the overall impact of the W-OH consolidation layer on the soil pore network structure from a three-dimensional spatial perspective. It provides key intrinsic structural parameters for evaluating the erosion resistance and durability of the W-OH consolidation layer, and strongly supports the mechanism explanation of its use as an efficient soil and water conservation material.

[0091] This invention, based on CT tomography, investigated the effects of hydrophilic polyurethane (W-OH) spraying on the pore structure of two typical soil types (QRC and GRS). The results showed that the W-OH solution, through infiltration and consolidation, filled soil pores, significantly reducing porosity and pore volume, while simultaneously increasing pore roundness, resulting in more regular and rounded pore shapes. Furthermore, the hydrophilic groups of the W-OH solution, through physical adsorption, covered the pore surface or filled pore spaces, reducing the effective pore surface area and connectivity, and enhancing the binding force between soil particles, thereby significantly improving the overall stability and erosion resistance of the soil. This invention provides important theoretical basis for the prevention and control of erosive soils, helping to overcome the current gap between W-OH theory and practice in soil erosion control, and promoting its wider application and improved effectiveness in soil erosion management.

[0092] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for analyzing the influence of soil pore structure based on W-OH spraying, characterized by: Perform steps A through D below to obtain an analysis of the consolidation depth of the target soil after W-OH spraying; Step A. Prepare W-OH solutions of various preset concentrations, including 0% concentration, and create target soil samples of preset heights corresponding to each W-OH solution of various concentrations. Spray each W-OH solution of various concentrations onto the surface of the corresponding target soil sample, and then proceed to Step B. Step B. For each W-OH solution of different concentrations, obtain the corresponding preset number of tomographic images of the target soil sample by CT scanning, and determine the tomographic image representing the soil surface as the first tomographic image. Obtain tomographic images corresponding to the preset soil depth from the first tomographic image to form the tomographic image set corresponding to the W-OH solution of different concentrations, and then proceed to step C. Step C. For each W-OH solution of different concentrations, obtain the porosity values ​​corresponding to each tomographic scan image in the corresponding tomographic image set. Based on the porosity coordinate system with porosity on the horizontal axis and soil depth on the vertical axis, mark the location of each porosity value and connect them to obtain the porosity curve corresponding to the W-OH solution of different concentrations. Then proceed to step D. Step D. Based on the porosity curves corresponding to each concentration of W-OH solution in the same porosity coordinate system, from the vertical axis 0 to the soil depth direction, obtain the first intersection point of the porosity curve corresponding to the 0% concentration W-OH solution with the porosity curves corresponding to the other concentrations of W-OH solutions. Take the soil depth corresponding to each intersection point as the consolidation depth corresponding to the other concentrations of W-OH solution, that is, obtain the consolidation depth of each preset concentration of W-OH solution with respect to the target soil for concentrations greater than 0%.

2. The method for analyzing the effect of W-OH spraying on soil pore structure according to claim 1, characterized in that: In step A, after each concentration of W-OH solution is sprayed onto the surface of the corresponding target soil sample, each target soil sample is left to stand for a preset time, then wrapped with plastic wrap to fix and protect for a preset time, and then proceeds to step B.

3. The method as claimed in claim 1, wherein the soil porosity analysis is based on W-OH spray. In step B, based on the target difference between the area ratio of the gray region corresponding to soil particles and the area ratio of the black region corresponding to air in the tomographic scan image, for each concentration of W-OH solution, based on the tomographic scan images of the corresponding target soil sample from top to bottom, the first tomographic scan image with a target difference less than a preset threshold is determined, thus forming the tomographic scan image representing the soil surface corresponding to the concentration of W-OH solution.

4. The method for analyzing the effect of soil pore structure based on W-OH spraying according to claim 1, characterized in that: In step C, for each W-OH solution of different concentrations, median filtering and image enhancement processing are performed on each tomographic scan image in the corresponding tomographic image set. After obtaining the grayscale histogram and combining it with the preset grayscale threshold, the soil structure binarized image of each tomographic scan image is obtained, and then the porosity value corresponding to each tomographic scan image is obtained.

5. The method for analyzing the influence of soil pore structure based on W-OH spraying according to claim 1 or 4, characterized in that: In step C, while obtaining the porosity curves corresponding to the W-OH solutions of each concentration, the process also includes obtaining the pore quantity, pore roundness, and average equivalent pore diameter values ​​corresponding to each tomographic scan image in the corresponding tomographic image set, and performing the following: Based on a pore number coordinate system with the horizontal axis representing the number of pores and the vertical axis representing the soil depth, the location of each pore number value is marked and connected to obtain the pore number curve corresponding to the concentration of W-OH solution. Based on a pore roundness coordinate system with the horizontal axis representing pore roundness and the vertical axis representing soil depth, the positions of each pore roundness value are marked and connected to obtain the pore roundness curve corresponding to the concentration W-OH solution. Based on the average equivalent pore size coordinate system with the horizontal axis representing the average equivalent pore size and the vertical axis representing the soil depth, the positions of each average equivalent pore size value are marked and connected to obtain the average equivalent pore size curve corresponding to the concentration W-OH ratio solution. In step D, based on the consolidation depth of the target soil with respect to the preset concentrations of W-OH solutions with a concentration greater than 0%, further for each concentration of W-OH solution with a concentration greater than 0%, obtain the pore quantity curve, pore roundness curve, and average equivalent pore diameter curve within the depth range from the soil surface to the corresponding consolidation depth, as well as the pore quantity curve, pore roundness curve, and average equivalent pore diameter curve within the depth range downward from the consolidation depth.

6. The method for analyzing the impact of W-OH spraying on soil pore structure according to claim 1 or 4, characterized in that: In step C, while obtaining the porosity curves corresponding to the W-OH solutions of each concentration, the process also includes obtaining the fractal dimension, anisotropy, pore surface area, and pore connectivity density values ​​corresponding to each tomographic scan image in the corresponding tomographic image set, and performing the following: Based on a fractal dimension coordinate system with fractal dimension on the horizontal axis and soil depth on the vertical axis, the positions of each fractal dimension value are marked and connected to obtain the fractal dimension curve corresponding to the concentration of W-OH solution. Based on an anisotropic coordinate system with anisotropy on the horizontal axis and soil depth on the vertical axis, the positions of each anisotropic value are marked and connected to obtain the anisotropic curves corresponding to the concentration W-OH ratio solution. Based on a pore surface area coordinate system with the horizontal axis representing pore surface area and the vertical axis representing soil depth, the location of each pore surface area value is marked and connected to obtain the pore surface area curve corresponding to the concentration W-OH ratio solution. Based on a pore connectivity density coordinate system with the horizontal axis representing pore connectivity density and the vertical axis representing soil depth, the location of each pore connectivity density value is marked and connected to obtain the pore connectivity density curve corresponding to the concentration W-OH solution. In step D, based on the consolidation depth of the target soil with respect to the preset concentrations of W-OH solutions with a concentration greater than 0%, the fractal dimension curve, anisotropy curve, pore surface area curve, and pore connectivity density curve are obtained for each concentration of W-OH solutions with a concentration greater than 0%, respectively, within the depth range from the soil surface to the corresponding consolidation depth. Additionally, the fractal dimension curve, anisotropy curve, pore surface area curve, and pore connectivity density curve are obtained within the depth range downward from the consolidation depth.

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