A method and system for evaluating the long-term stability of expansive soil channel slopes

Abstract

The present invention provides an evaluation method and system for the long-term stability of expansive soil channel slopes. The method establishes multiple main evaluation factors affecting the long-term stability of expansive soil channel slopes and their corresponding secondary evaluation factors, and constructs an evaluation hierarchical framework. The method uses the AHP (Analytical Hierarchy Process) to establish a relative importance ratio scale to construct a judgment matrix. After constructing the judgment matrix, the weights of each evaluation factor are calculated, and a consistency check is performed on the judgment matrix to avoid logical errors. Finally, by formulating scoring criteria for each secondary evaluation factor and the calculated weights of each evaluation factor, an overall score for the long-term stability of the expansive soil channel slope is calculated, and the long-term stability of the expansive soil channel slope is graded and evaluated based on the overall score. The method solves the problem that traditional stability calculation and analysis methods cannot predict the long-term stability of expansive soil channel slopes, and provides a basis for channel construction and safe operation design in expansive soil areas.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering design and relates to a slope stability evaluation method and system. Background Art

[0002] Slope deformation and instability in expansive soils is the most significant challenge facing channel construction and safe operation in expansive soil regions. It is characterized by high frequency, difficulty in prediction, and significant challenges in post-construction management. Among expansive soil channel slope instability, structural surface-controlled landslides are relatively large in scale, and the time between slope excavation and sliding failure varies significantly, with some cases experiencing instability immediately upon excavation, while others lag behind for years or even decades. The typical lag time for instability ranges from a few months to approximately two years.

[0003] However, expansive soils have unique engineering properties. Their overconsolidation causes significant unloading rebound during excavation, leading to crack opening and increased soil moisture content. Furthermore, the multi-fissure nature of expansive soils is the primary cause of repeated dry-wet cycles and strength loss in the soil. Their dilatation and contraction are the primary cause of structural damage and cracking in shallow soils. Due to the unique failure mechanism of expansive soils, the instability of expansive soil channel slopes is subject to numerous internal and external factors. Traditional stability analysis methods or deformation monitoring are used to assess the stability of expansive soil channel slopes, resulting in significant uncertainty and difficulty in predicting and assessing the long-term stability of expansive soil slopes. This presents challenges in the design of engineering slope treatments. Either overly conservative plans result in construction waste, or insufficient risk awareness leads to inadequate treatment measures. If slope instability occurs during channel operation, it can result in significant direct losses and high treatment costs. Summary of the Invention

[0004] In order to solve the problem that the long-term stability of expansive soil slopes described in the background art is difficult to predict and evaluate, the present invention provides a method and system for evaluating the long-term stability of expansive soil channel slopes.

[0005] The method of the present invention comprises the following steps:

[0006] S1. Based on historical data on the long-term stability of expansive soil channel slopes, the deformation and failure mechanisms of expansive soil channel slopes, and the characteristics of expansive soil, determine multiple primary evaluation factors affecting the long-term stability of expansive soil channel slopes; for each primary evaluation factor, establish at least one corresponding secondary evaluation factor, construct an evaluation hierarchy for the long-term stability prediction of expansive soil channel slopes, and formulate scoring criteria for each secondary evaluation factor based on the actual conditions of each secondary evaluation factor for the long-term stability prediction of expansive soil channel slopes;

[0007] S2. Establish a relative importance scale based on the AHP, compare each major evaluation factor pairwise, assign values ​​based on the relative importance scale, and construct a judgment matrix to calculate the weight of each major evaluation factor; compare each minor evaluation factor pairwise, assign values ​​based on the relative importance scale, and construct a judgment matrix to calculate the weight of each minor evaluation factor;

[0008] S3. Perform a consistency check on the constructed judgment matrix to calculate a consistency check factor CR. If the consistency check factor CR is less than 0.1, output the evaluation hierarchy framework for the long-term stability prediction of the expansive soil channel slope, the weights of each main evaluation factor, and the weights of each secondary evaluation factor. If the consistency check factor CR is greater than or equal to 0.1, repeat the operation of step S2 and perform the consistency check again until CR is less than 0.1.

[0009] S4. Based on the prediction and evaluation system for the long-term stability of expansive soil channel slopes, which is composed of the evaluation hierarchy for the prediction of the long-term stability of expansive soil channel slopes, the scoring criteria for each secondary evaluation factor, the weights of each main evaluation factor and the weights of each secondary evaluation factor, the total score of the long-term stability of the expansive soil channel slope is calculated, and the long-term stability of the expansive soil channel slope is graded and evaluated according to the total score.

[0010] Furthermore, in S1, the main evaluation factors for the long-term stability of the expansive soil channel slope include: expansion and contraction characteristics, crack characteristics, geological structure, hydrogeology and engineering factors.

[0011] Furthermore, in S1, the secondary evaluation factors corresponding to the main evaluation factor expansion and contraction characteristics include: expansibility, formation age; the secondary evaluation factors corresponding to the main evaluation factor fracture characteristics include: length of large fractures, occurrence of large fractures, connectivity rate of gentle fractures, undulation state of large fracture surfaces, filling condition of large fracture surfaces, and degree of development of micro fractures; the secondary evaluation factors corresponding to the main evaluation factor geological structure include: stratigraphic interface, expansive interface, and interlayer with strong expansibility; the secondary evaluation factors corresponding to the main evaluation factor hydrogeology include: groundwater occurrence type, rock and soil water richness, and slope seepage condition; the secondary evaluation factors corresponding to the main evaluation factor engineering factors include: slope height, excavation slope ratio, construction protection, and engineering treatment measures.

[0012] Furthermore, in 2, the relative importance scale is the importance value of the i-th evaluation factor compared to the j-th evaluation factor, where 1≤i≤n, 1≤j≤n, and n is the number of evaluation factors; when extremely important, the relative importance scale is 9, when very important, the relative importance scale is 7, when important, the relative importance scale is 5, when slightly important, the relative importance scale is 3, when equally important, the relative importance scale is 1, when slightly less important, the relative importance scale is 1 / 3, when less important, the relative importance scale is 1 / 5, when less important, the relative importance scale is 1 / 5, when very less important, the relative importance scale is 1 / 7, and when extremely less important, the relative importance scale is 1 / 9.

[0013] Furthermore, in S2, the judgment matrix A is:

[0014]

[0015] Among them, a ij Indicates the evaluation factors {A1, A2, A3…A n Any two items A i 、A j The relative importance of ; 1≤i≤n, 1≤j≤n, n is the number of evaluation factors.

[0016] Furthermore, in said S2, it is assumed that the evaluation factors {A1, A2, A3...A n}When an element at the previous level is used as the evaluation benchmark, its weight values ​​are {w1, w2, w3…w n}, then the vector formed by the weight values ​​is expressed as follows:, then the vector formed by the weight values ​​is expressed as follows:

[0017]

[0018] Then the judgment matrix A can be rewritten as:

[0019]

[0020]

[0021] Furthermore, in S3, the judgment factor CR of the consistency check is:

[0022]

[0023] in, λ max is the largest characteristic root, n is the number of evaluation factors; RI is the average random consistency test index, which is determined by the dimension of the judgment matrix.

[0024] The invention proposes an evaluation system for the long-term stability of expansive soil channel slopes, which includes an evaluation hierarchy framework and scoring criteria construction module, an evaluation factor weight calculation module, a consistency verification module and a long-term stability classification evaluation module.

[0025] The evaluation hierarchical framework construction module is used to determine multiple main evaluation factors affecting the long-term stability of expansive soil channel slopes based on historical data on the long-term stability of expansive soil channel slopes, the deformation and failure mechanism of expansive soil channel slopes, and the characteristics of expansive soil; for each main evaluation factor, at least one corresponding secondary evaluation factor is established to construct an evaluation hierarchical framework for the long-term stability prediction of expansive soil channel slopes; and based on the actual conditions of each secondary evaluation factor for the long-term stability prediction of expansive soil channel slopes, scoring criteria for each secondary evaluation factor are formulated.

[0026] The weight calculation module of the evaluation factors is used to establish a relative importance ratio scale based on the AHP hierarchical analysis method, compare each main evaluation factor in pairs, assign values ​​based on the relative importance ratio scale, and construct a judgment matrix to calculate the weight of each main evaluation factor; compare each secondary evaluation factor in pairs, assign values ​​based on the relative importance ratio scale, and construct a judgment matrix to calculate the weight of each secondary evaluation factor.

[0027] The consistency check module is used to perform a consistency check on the constructed judgment matrix to calculate a consistency check factor CR. If the consistency check factor CR is less than 0.1, the evaluation hierarchy framework for the long-term stability prediction of the expansive soil channel slope, the weights of each main evaluation factor and the weights of each secondary evaluation factor are output; if the consistency check factor CR is greater than or equal to 0.1, the operation of the evaluation factor weight calculation module is repeated, and the consistency check is performed again until CR is less than 0.1.

[0028] The long-term stability grading assessment module is used to calculate the total score of the long-term stability of the expansive soil channel slope based on the assessment hierarchy framework for the long-term stability prediction of the expansive soil channel slope, the scoring criteria of each secondary assessment factor, the weight of each main assessment factor and the weight of each secondary assessment factor, and to perform a graded assessment of the long-term stability of the expansive soil channel slope according to the total score.

[0029] The present invention also proposes an electronic device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to implement the above-mentioned method for evaluating the long-term stability of an expansive soil channel slope and the system for evaluating the long-term stability of an expansive soil channel slope.

[0030] The present invention also proposes a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the above-mentioned method for evaluating the long-term stability of an expansive soil channel slope and the system for evaluating the long-term stability of an expansive soil channel slope.

[0031] Compared with the prior art, the present invention establishes multiple main evaluation factors and their corresponding secondary evaluation factors affecting the long-term stability of expansive soil channel slopes based on historical data on the long-term stability of expansive soil channel slopes, the deformation and failure mechanism of expansive soil channel slopes, and the characteristics of expansive soil, and constructs an evaluation hierarchical framework. The AHP (Analytic Hierarchy Process) method, which combines quantitative analysis with qualitative analysis, establishes a relative importance scale to construct a judgment matrix. The judgment matrix is ​​constructed, the weights of each evaluation factor are calculated, and a consistency check is performed on the judgment matrix to avoid logical errors. Finally, by formulating scoring criteria for each secondary evaluation factor and the calculated weights of each evaluation factor, an overall score for the long-term stability of the expansive soil channel slope is calculated, and the long-term stability of the expansive soil channel slope is graded and evaluated based on the overall score. The present invention solves the problem that traditional stability calculation and analysis methods cannot predict the long-term stability of expansive soil channel slopes, and provides a basis for channel construction and safe operation design in expansive soil areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Flow chart of the method of the present invention.

[0033] Figure 2 This is a system architecture diagram of the present invention. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0035] Deformation failure of expansive soil slopes can be categorized by depth into shallow collapse failure in the expansion-contraction zone and deep sliding failure controlled by structural surfaces. Due to the distinct vertical zonation of expansive soil structure, groundwater storage conditions, and engineering properties, the failure mode of expansive soil is closely related to excavation depth. Shallow failure lacks a distinct sliding surface and is typically less than 1 meter deep. Structural-surface-controlled landslides typically occur within and below the transition zone, sliding along gently dipping, long fissures or tracking natural lithologic interfaces or zones of dense fissures. Depths typically range from 3 to 8 meters, with a maximum observed depth of 20 meters.

[0036] Expansive soil landslides controlled by structural surfaces share common morphological characteristics: a nearly horizontal bottom sliding surface, a steeply inclined trailing edge, and a broken-line profile. Expansive soil landslides or displacement development typically occur during rainfall. Landslides caused by excavation of the expansive soil channel along the middle route of the South-to-North Water Diversion Project show that landslide formation is closely related to the dilatancy of the channel slope soil, the density of large cracks, the distribution of interlayers, groundwater activity, slope ratio, and channel slope height. Large cracks and interlayers are intrinsic factors controlling landslides, while strain softening caused by excavation unloading and groundwater or rainwater infiltration are the primary triggers.

[0037] There are two mechanisms for structural surface-controlled landslides: First, after excavation, overconsolidated soil releases stress and produces rebound deformation. Tensile stress concentrates near the slope brow, accommodating steeply dipping cracks that follow the slope. Water pressure and expansion forces cause expansion of the ends of the sub-horizontal cracks or shear creep of the structural surface. Second, when the confining pressure of the expansive soil decreases, the new soil-water equilibrium causes water absorption and expansion, softening the structural surface and reducing its strength. The time lag of failure depends on the time it takes for sub-horizontal cracks to gradually connect or for the strength of the weak structural surface to gradually decay.

[0038] The present invention proposes a method for evaluating the long-term stability of expansive soil channel slopes, the flow chart of which is as follows: Figure 1 As shown, the specific steps are described in detail below.

[0039] S1. Based on the historical data on the long-term stability of expansive soil channel slopes, the deformation and failure mechanism of expansive soil channel slopes, and the characteristics of expansive soil, determine multiple main evaluation factors affecting the long-term stability of expansive soil channel slopes; for each main evaluation factor, establish at least one corresponding secondary evaluation factor, construct an evaluation hierarchy for the long-term stability prediction of expansive soil channel slopes, and formulate scoring criteria for each secondary evaluation factor based on the actual conditions of each secondary evaluation factor for the long-term stability prediction of expansive soil channel slopes.

[0040] Specifically, historical data on the long-term stability of expansive soil channel slopes, such as the extensive research on the engineering properties of expansive soil in Nanyang, the Middle Route of the South-to-North Water Diversion Project, and the characteristics of expansive soils, such as their unique engineering geology and vertical zoning, were used. Five key factors affecting the long-term stability of expansive soil channel slopes were identified: expansion-contraction characteristics, crack characteristics, geological structure, hydrogeology, and engineering factors.

[0041] The secondary evaluation factors corresponding to the expansion and contraction characteristics are: expansibility and formation age.

[0042] The secondary evaluation factors corresponding to the crack characteristics include: the length of large cracks, the occurrence of large cracks, the connectivity rate of gently inclined cracks, the undulation of large crack surfaces, the filling condition of large crack surfaces, and the degree of development of micro-cracks.

[0043] The secondary evaluation factors corresponding to the geological structure include: stratum interface, expansive interface, and interlayer with strong expansibility.

[0044] The secondary assessment factors corresponding to hydrogeology include: groundwater storage type, rock and soil water richness, and slope seepage conditions.

[0045] The secondary evaluation factors corresponding to engineering factors include: slope height, excavation slope ratio, construction protection, and engineering treatment measures.

[0046] After sorting out and analyzing the hierarchical order relationship of the above evaluation factors, an evaluation hierarchy framework for long-term stability prediction of expansive soil channel slopes can be constructed.

[0047] A graded scoring system was used, assigning a score of 2 to 10 to each secondary assessment factor. When the secondary assessment factors were divided into three levels, the stability scores were 10, 6, and 2, respectively, from poor to good. When the secondary assessment factors were divided into five levels, the stability scores were 10, 8, 6, 4, and 2, respectively, from poor to good. The established scoring criteria for the long-term stability prediction of expansive soil channel slopes are shown in Table 1.

[0048] Table 1 Scoring criteria for long-term channel slope stability prediction

[0049]

[0050]

[0051] S2. Establish a relative importance scale based on the AHP, compare each main evaluation factor pairwise, assign values ​​based on the relative importance scale, and construct a judgment matrix to calculate the weight of each main evaluation factor; compare each secondary evaluation factor pairwise, assign values ​​based on the relative importance scale, and construct a judgment matrix to calculate the weight of each secondary evaluation factor.

[0052] Specifically, the relative importance ratio scale is the importance of the i-th evaluation factor compared to the j-th evaluation factor, where 1≤i≤n, 1≤j≤n, and n is the number of evaluation factors, as shown in Table 2. The values ​​in the table represent the importance of the former compared to the latter, measured on a 1-9 scale. If the former is more important than the latter, a value between 1-9 is entered, with values ​​of 1, 3, 5, 7, and 9 representing the importance of the i-th factor compared to the j-th factor: equally important, slightly important, important, very important, and extremely important, respectively. The larger the number, the greater the importance. Otherwise, a value between 1 / 3 and 1 / 9 is entered, with values ​​of 1 / 3, 1 / 5, 1 / 7, and 1 / 9.

[0053] Table 2 Relative importance scale

[0054]

[0055] Note: 8, 6, 4, 2, 1 / 2, 1 / 4, 1 / 6, and 1 / 8 are taken as the middle values ​​of the above evaluation values.

[0056] The judgment matrix A is:

[0057]

[0058] Among them, a ij Indicates the evaluation factors {A1, A2, A3…A n Any two items A i 、A j The relative importance of ; 1≤i≤n, 1≤j≤n, n is the number of evaluation factors.

[0059] Assume that the evaluation factors {A1, A2, A3…A n}When an element at the previous level is used as the evaluation benchmark, its weight values ​​are {w1, w2, w3, ..., w n}, then the vector composed of weight values ​​is expressed as follows:

[0060]

[0061] Then the judgment matrix A can be rewritten as:

[0062]

[0063] S3. Perform a consistency check on the constructed judgment matrix to calculate the consistency check factor CR. If the consistency check factor CR is less than 0.1, output the evaluation hierarchy framework for the long-term stability prediction of the expansive soil channel slope, the weights of each main evaluation factor, and the weights of each secondary evaluation factor. If the consistency check factor CR is greater than or equal to 0.1, repeat the operation of step S2 and perform the consistency check again until CR is less than 0.1.

[0064] Specifically, the judgment factor CR of the consistency test is:

[0065]

[0066] in, λ max is the largest characteristic root, n is the number of evaluation factors; RI is the average random consistency test index, which is determined by the dimension of the judgment matrix. Its specific value is shown in Table 3 below.

[0067] Table 3 Average random consistency test index RI value

[0068] n 1 2 3 4 5 6 7 8 9 RI 0 0 0.52 0.89 1.12 1.26 1.36 1.41 1.46

[0069] S4. Based on the prediction and evaluation system for the long-term stability of expansive soil channel slopes, which is composed of the evaluation hierarchy for the prediction of the long-term stability of expansive soil channel slopes, the scoring criteria for each secondary evaluation factor, the weights of each main evaluation factor and the weights of each secondary evaluation factor, the total score of the long-term stability of the expansive soil channel slope is calculated, and the long-term stability of the expansive soil channel slope is graded and evaluated according to the total score.

[0070] The obtained grading evaluation table for the long-term stability of expansive soil channel slope is shown in Table 4.

[0071] Table 4 Classification evaluation table for long-term stability of expansive soil channel slope

[0072] Rating value ＜20 21-40 41-60 61-80 81-100 level Ⅰ Ⅱ Ⅲ Ⅳ Ⅴ Stability judgment Good stability Good stability Average stability Poor stability Poor stability

[0073] The present invention also proposes an evaluation system for the long-term stability of expansive soil channel slopes, the structure of which is shown in FIG. Figure 2 As shown in the figure, it consists of an evaluation hierarchy framework and scoring criteria construction module, an evaluation factor weight calculation module, a consistency verification module and a long-term stability grading evaluation module.

[0074] An evaluation hierarchy framework construction module is used to determine multiple main evaluation factors affecting the long-term stability of expansive soil channel slopes based on historical data on the long-term stability of expansive soil channel slopes, the deformation and failure mechanism of expansive soil channel slopes, and the characteristics of expansive soil; for each main evaluation factor, at least one corresponding secondary evaluation factor is established to construct an evaluation hierarchy framework for the long-term stability prediction of expansive soil channel slopes; and based on the actual conditions of each secondary evaluation factor for the long-term stability prediction of expansive soil channel slopes, scoring criteria for each secondary evaluation factor are formulated.

[0075] The weight calculation module of the evaluation factors is used to establish a relative importance ratio scale based on the AHP hierarchical analysis method, compare each main evaluation factor pairwise, assign values ​​based on the relative importance ratio scale, and construct a judgment matrix to calculate the weight of each main evaluation factor; compare each secondary evaluation factor pairwise, assign values ​​based on the relative importance ratio scale, and construct a judgment matrix to calculate the weight of each secondary evaluation factor.

[0076] The consistency check module is used to perform consistency check on the constructed judgment matrix and calculate the consistency check factor CR. If the consistency check factor CR is less than 0.1, the evaluation hierarchy framework for the long-term stability prediction of the expansive soil channel slope, the weights of each main evaluation factor and the weights of each secondary evaluation factor are output; if the consistency check factor CR is greater than or equal to 0.1, the operation of the evaluation factor weight calculation module is repeated, and then the consistency check is performed until CR is less than 0.1.

[0077] The long-term stability grading assessment module is used to calculate the total score of the long-term stability of the expansive soil channel slope based on the assessment hierarchy framework for the long-term stability prediction of the expansive soil channel slope, the scoring criteria for each secondary assessment factor, the weights of each main assessment factor and the weights of each secondary assessment factor, and to conduct a graded assessment of the long-term stability of the expansive soil channel slope according to the total score.

[0078] The specific implementation of each module in the system is consistent with that described in the above method and will not be repeated here.

[0079] The present invention also proposes an electronic device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to implement the above-mentioned method for evaluating the long-term stability of an expansive soil channel slope and the system for evaluating the long-term stability of an expansive soil channel slope.

[0080] The present invention also proposes a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the above-mentioned method for evaluating the long-term stability of an expansive soil channel slope and the system for evaluating the long-term stability of an expansive soil channel slope.

[0081] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiment of the present application can be implemented in various computer languages, for example, object-oriented programming languages ​​Java, C++, Python, and literal translation scripting language JavaScript, etc.

[0082] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0083] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0084] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0085] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0086] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A method for evaluating the long-term stability of expansive soil channel slopes, characterized in that: The following steps are involved: S1. Based on historical data on the long-term stability of expansive soil channel slopes, the deformation and failure mechanisms of expansive soil channel slopes, and the characteristics of expansive soil, determine multiple primary evaluation factors affecting the long-term stability of expansive soil channel slopes. For each primary evaluation factor, establish at least one corresponding secondary evaluation factor, construct an evaluation hierarchy for the long-term stability prediction of expansive soil channel slopes, and develop scoring criteria for each secondary evaluation factor based on the actual conditions of each secondary evaluation factor for the long-term stability prediction of expansive soil channel slopes. The main evaluation factors for the long-term stability of the expansive soil channel slope include: expansion and contraction characteristics, crack characteristics, geological structure, hydrogeology and engineering factors; The secondary evaluation factors corresponding to the main evaluation factor expansion and contraction characteristics include: expansion and formation age; the secondary evaluation factors corresponding to the main evaluation factor fracture characteristics include: length of large fractures, occurrence of large fractures, connectivity rate of gently dipping fractures, undulation of large fracture surfaces, filling of large fracture surfaces, and degree of development of micro-fractures; the secondary evaluation factors corresponding to the main evaluation factor geological structure include: stratigraphic interface, expansion interface, and interlayer with strong expansion; the secondary evaluation factors corresponding to the main evaluation factor hydrogeology include: groundwater occurrence type, rock and soil water richness, and slope seepage condition; the secondary evaluation factors corresponding to the main evaluation factor engineering factors include: slope height, excavation slope ratio, construction protection, and engineering treatment measures; S2. Establish a relative importance scale based on the AHP, compare each major evaluation factor pairwise, assign values ​​based on the relative importance scale, and construct a judgment matrix to calculate the weight of each major evaluation factor; compare each minor evaluation factor pairwise, assign values ​​based on the relative importance scale, and construct a judgment matrix to calculate the weight of each minor evaluation factor; S3. Perform consistency test on the constructed judgment matrix and calculate the consistency test factor CR , if the consistency test factor CR <0.1, then the evaluation hierarchy of the long-term stability prediction of the expansive soil channel slope, the weights of each main evaluation factor and the weights of each secondary evaluation factor are output; if the consistency test factor CR ≥0.1, repeat step S2 and perform consistency check again until CR <0.1; S4. Based on the prediction and evaluation system for the long-term stability of expansive soil channel slopes, which is composed of the evaluation hierarchy for the prediction of the long-term stability of expansive soil channel slopes, the scoring criteria for each secondary evaluation factor, the weights of each main evaluation factor and the weights of each secondary evaluation factor, the total score of the long-term stability of the expansive soil channel slope is calculated, and the long-term stability of the expansive soil channel slope is graded and evaluated according to the total score.

2. The method for evaluating the long-term stability of an expansive soil channel slope according to claim 1, wherein: In S2, the relative importance scale is i The evaluation factors are compared with j The importance value of the evaluation factors, where 1≤ i ≤ n , 1≤ j ≤ n , n is the number of evaluation factors; When extremely important, the relative importance scale is 9; when very important, the relative importance scale is 7; when important, the relative importance scale is 5; when slightly important, the relative importance scale is 3; when equally important, the relative importance scale is 1; when slightly less important, the relative importance scale is 1 / 3; when less important, the relative importance scale is 1 / 5; when less important, the relative importance scale is 1 / 5; when very less important, the relative importance scale is 1 / 7; when extremely less important, the relative importance scale is 1 / 9.

3. The method for evaluating the long-term stability of an expansive soil channel slope according to claim 2, wherein: In S2, the judgment matrix A is: （1）， Among them, a ij Indicates the evaluation factors {A1, A2, A3…A n Any two items A i 、A j The relative importance of i ≤ n , 1≤ j ≤ n , n is the number of evaluation factors.

4. The method for evaluating the long-term stability of an expansive soil channel slope according to claim 3, wherein: In S2, it is assumed that the evaluation factors {A1, A2, A3...A n }When an element at the previous level is used as the evaluation benchmark, its weight values ​​are {w1, w2, w3…w n }, then the vector composed of weight values ​​is expressed as follows: （2）； Then the judgment matrix A can be rewritten as:

5. The method for evaluating the long-term stability of an expansive soil channel slope according to claim 4, wherein: In S3, the judgment factor of consistency test CR for: ； in, ;λ max is the largest characteristic root, , n is the number of evaluation factors; RI is the average random consistency test index, which is determined by the dimension of the judgment matrix.

6. A system for evaluating the long-term stability of expansive soil channel slopes, characterized by: It includes the evaluation hierarchy framework and scoring criteria construction module, the evaluation factor weight calculation module, the consistency verification module and the long-term stability classification evaluation module; The evaluation hierarchical framework construction module is used to determine multiple main evaluation factors affecting the long-term stability of expansive soil channel slopes based on historical data on the long-term stability of expansive soil channel slopes, the deformation and failure mechanism of expansive soil channel slopes, and the characteristics of expansive soil; for each main evaluation factor, establish at least one corresponding secondary evaluation factor to construct an evaluation hierarchical framework for the long-term stability prediction of expansive soil channel slopes; and formulate scoring criteria for each secondary evaluation factor based on the actual conditions of each secondary evaluation factor for the long-term stability prediction of expansive soil channel slopes; The main evaluation factors for the long-term stability of the expansive soil channel slope include: expansion and contraction characteristics, crack characteristics, geological structure, hydrogeology and engineering factors; The secondary evaluation factors corresponding to the main evaluation factor expansion and contraction characteristics include: expansion and formation age; the secondary evaluation factors corresponding to the main evaluation factor fracture characteristics include: length of large fractures, occurrence of large fractures, connectivity rate of gently dipping fractures, undulation of large fracture surfaces, filling of large fracture surfaces, and degree of development of micro-fractures; the secondary evaluation factors corresponding to the main evaluation factor geological structure include: stratigraphic interface, expansion interface, and interlayer with strong expansion; the secondary evaluation factors corresponding to the main evaluation factor hydrogeology include: groundwater occurrence type, rock and soil water richness, and slope seepage condition; the secondary evaluation factors corresponding to the main evaluation factor engineering factors include: slope height, excavation slope ratio, construction protection, and engineering treatment measures; The weight calculation module of the evaluation factors is used to establish a relative importance scale based on the AHP hierarchical analysis method, compare each main evaluation factor in pairs, assign values ​​based on the relative importance scale, and construct a judgment matrix to calculate the weight of each main evaluation factor; compare each secondary evaluation factor in pairs, assign values ​​based on the relative importance scale, and construct a judgment matrix to calculate the weight of each secondary evaluation factor; The consistency check module is used to perform consistency check on the constructed judgment matrix and calculate the consistency check factor CR , if the consistency test factor CR <0.1, then the evaluation hierarchy of the long-term stability prediction of the expansive soil channel slope, the weights of each main evaluation factor and the weights of each secondary evaluation factor are output; if the consistency test factor CR ≥0.1, repeat the operation of the weight calculation module of the evaluation factor and then perform consistency check until CR <0.1; The long-term stability grading assessment module is used to calculate the total score of the long-term stability of the expansive soil channel slope based on the assessment hierarchy framework for the long-term stability prediction of the expansive soil channel slope, the scoring criteria of each secondary assessment factor, the weight of each main assessment factor and the weight of each secondary assessment factor, and to perform a graded assessment of the long-term stability of the expansive soil channel slope according to the total score.

7. An electronic device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor implements the method for evaluating the long-term stability of an expansive soil channel slope as described in any one of claims 1 to 5 by executing the computer instructions.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for evaluating the long-term stability of an expansive soil channel slope according to any one of claims 1 to 5 is implemented.

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