A safety evaluation method for stability of high and steep valley slope under multi-point earthquake

Abstract

This invention relates to the field of disaster assessment technology, specifically a safety assessment method for the stability of steep valley slopes under multi-point earthquakes. The method includes: determining the initial candidate range of the slip surface for the steep valley slope based on the slope type and core parameter information, and based on limit equilibrium theory; searching for the most dangerous slip surface using a particle swarm optimization algorithm based on the initial candidate range and the core parameter information; and dividing the slope area where the most dangerous slip surface is located into blocks using the limit equilibrium slice method based on the most dangerous slip surface and the core parameter information, thereby obtaining the stress characteristic parameters of each block. This invention, by employing a particle swarm optimization algorithm, can automatically search for the most dangerous slip surface within the initial candidate range, avoiding the subjective bias and inaccuracy of manual slip surface selection; through iterative updates of the algorithm, the location of the most dangerous slip surface can be accurately captured, improving the accuracy of stability analysis.

Description

Technical Field

[0001] This application relates to the field of disaster assessment technology, and in particular to a safety evaluation method for the stability of steep valley slopes under multi-point earthquakes. Background Technology

[0002] Steep slopes in river valleys are usually located on both sides of a river or in areas related to the river. The slopes are steep, often exceeding 30 degrees or even approaching vertical. This type of terrain is generally formed by the combined effects of natural forces such as water erosion, river scouring, and geological changes.

[0003] Currently, traditional methods typically analyze slope stability based on a single point of seismic action, failing to fully consider the synergistic effects of multiple seismic sources. The impact of different seismic action points on slopes varies significantly, and single-point analysis may not accurately reflect the comprehensive impact of seismic action on slope stability. Furthermore, in traditional methods, the slip surface usually needs to be selected based on experience or assumptions, which involves strong subjectivity and may result in the selected slip surface not being the most dangerous, thus affecting the accuracy of stability assessment.

[0004] Furthermore, traditional methods generally employ relatively simple force models, making it difficult to consider the interactions between different sections of the slope. Especially under seismic loading, the normal and tangential forces between sections can significantly impact slope stability, and the coarse force analysis of traditional methods cannot fully reveal these complex factors. In addition, traditional methods rarely consider topographic sensitivity and the distribution of earthquake sources, often assuming a uniform distribution of seismic forces, while the actual seismic wave propagation characteristics and topographic features have a significant impact on slope stability. Summary of the Invention

[0005] The main objective of this application is to provide a safety evaluation method for the stability of steep valley slopes under multi-point earthquakes, in order to solve the problems existing in the prior art.

[0006] To achieve the above objectives, this application provides the following technical solution: A safety assessment method for the stability of steep valley slopes under multi-point earthquakes includes: Obtain the original parameter information of the steep slope of the valley, and based on the original parameter information, determine the slope type and core parameter information of the steep slope of the valley; Based on the slope type and core parameter information, and based on the limit equilibrium theory, the initial sliding surface candidate range of the steep valley slope is determined; based on the initial sliding surface candidate range and the core parameter information, the particle swarm optimization algorithm is used to search for the most dangerous sliding surface; Based on the most dangerous sliding surface and the core parameter information, the slope area where the most dangerous sliding surface is located is divided into blocks using the limit equilibrium slice method to obtain the stress characteristic parameters of each block; Based on the stress characteristic parameters and slope type of each block, the stability safety factor of the steep valley slope under single-point seismic action is calculated using the Yangbu method; based on the stability safety factor and the preset single-point safety factor range, the stability level of the steep valley slope under single-point seismic action is determined. Based on the slope stability level corresponding to different seismic action points and the influence weight of each action point, the multi-point seismic comprehensive stability safety factor is determined. Based on the comprehensive stability safety factor of the multi-point earthquake and the preset comprehensive safety factor range, the final safety evaluation result of the steep slope of the valley under multi-point earthquake is determined.

[0007] Preferably, based on the slope type and core parameter information, and based on the limit equilibrium theory, the candidate range of the initial sliding surface of the steep valley slope is determined, including: If the slope type is a rock slope, the candidate range of the initial sliding surface is determined based on the rock mass integrity index and structural surface development characteristics in the core parameter information, as well as the mechanical critical conditions for rock mass failure in the limit equilibrium theory. If the slope type is a soil slope, the candidate range of the initial sliding surface is determined based on the soil cohesion and internal friction angle in the core parameter information, and the critical value of soil shear strength in the limit equilibrium theory. If the slope type is a mixed slope, the candidate range of the initial sliding surface is determined based on the characteristics of rock and soil regional distribution in the core parameter information, and the synergistic effect of failure of different media in the limit equilibrium theory.

[0008] Preferably, based on the initial candidate range of sliding surfaces and the core parameter information, a particle swarm optimization algorithm is used to search for the most dangerous sliding surface, including: Based on the slope shear strength index and the boundary constraints of the initial sliding surface candidate range in the core parameter information, the initial particle position and search range of the particle swarm optimization algorithm are determined. With the minimization of the slope stability safety factor as the objective function, the particle swarm optimization algorithm iteratively updates the particle positions to screen out potential sliding surfaces that meet the constraints. Based on the stability-related parameters corresponding to the potential sliding surface and the discrimination criteria of the limit equilibrium theory, the most dangerous sliding surface is determined.

[0009] Preferably, based on the most dangerous sliding surface and the core parameter information, the slope area where the most dangerous sliding surface is located is divided into blocks using the limit equilibrium slice method to obtain the stress characteristic parameters of each block, including: Based on the curvature change characteristics of the most dangerous sliding surface and the slope distribution in the core parameter information, the number of blocks and the division boundaries are determined. According to the defined boundary, the slope area where the most dangerous sliding surface is located is divided into several continuous blocks. The self-weight distribution characteristics, normal force characteristics and tangential force characteristics of the contact surface between the blocks are extracted to obtain the force characteristic parameters of each block.

[0010] Preferably, based on the stress characteristic parameters and slope type of each block, the stability safety factor of the steep valley slope under single-point seismic loading is calculated using the Yangbu method, including: The applicable correction coefficient of the spreading method is determined based on the slope type, and the force balance relationship between the blocks is constructed based on the normal force and tangential force in the force characteristic parameters of each block. By considering the influence of the direction and magnitude of the forces between the strips using the aforementioned method, the anti-slip torque and sliding torque of each strip are solved iteratively step by step. Based on the ratio of the anti-sliding moment to the sliding moment, the stability safety factor of the steep slope of the valley under single-point seismic action is obtained.

[0011] Preferably, based on the slope stability level corresponding to different seismic action points and the influence weight of each action point, a multi-point seismic comprehensive stability safety factor is determined, including: Based on the source characteristics of each earthquake action point and the topographic sensitivity distribution characteristics of the slope, the influence weight corresponding to each earthquake action point is determined. Extract the stability safety factor associated with the slope stability level corresponding to each earthquake action point; Based on the weights of each influence and the corresponding stability safety coefficients, a multi-point earthquake comprehensive stability safety coefficient is obtained through a weighted fusion method.

[0012] Preferably, based on the source characteristics of each earthquake action point and the topographic sensitivity distribution characteristics of the slope, the influence weight corresponding to each earthquake action point is determined, including: Based on the characteristics of earthquake intensity and propagation path in the source characteristics, determine the degree of impact of the earthquake action point on the foundation of the slope; Based on the slope height and slope angle distribution in the topographic sensitive distribution characteristics of the slope, the sensitivity coefficients of different areas of the slope to seismic action are determined. Based on the aforementioned basic influence level and sensitivity coefficient, the influence weight corresponding to each seismic action point is determined through comprehensive quantitative analysis.

[0013] Preferred options also include: Based on the final safety assessment results and the engineering requirements of the slope, the risk level of the slope is determined; Based on the risk level and the preset risk management measures library, a corresponding slope reinforcement optimization scheme is matched.

[0014] This application calculates a comprehensive stability safety factor by weighted fusion of stability safety factors at different seismic action points, providing a more comprehensive evaluation of slope stability under multi-point seismic conditions. Furthermore, by employing a particle swarm optimization algorithm, it can automatically search for the most dangerous slip surface within the initial candidate range, avoiding the subjective bias and inaccuracy of manual slip surface selection. Through iterative updates of the algorithm, the location of the most dangerous slip surface can be accurately captured, improving the accuracy of stability analysis. Moreover, by using the limit equilibrium slice method to divide the area containing the most dangerous slip surface into blocks, it can refine the force characteristics of each block, considering the normal and tangential forces between blocks, helping to deeply understand the behavior of slopes under seismic action and improving the detail and scientific rigor of stability analysis. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating the steps of an embodiment of a safety evaluation method for the stability of steep valley slopes under multi-point earthquakes according to this application. Detailed Implementation

[0016] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0017] like Figure 1 As shown, the present invention proposes a safety evaluation method for the stability of steep valley slopes under multi-point earthquakes, comprising: S1. Obtain the original parameter information of the steep slopes in the valley, and determine the slope type and core parameter information of the steep slopes in the valley based on the original parameter information; S2. Based on slope type and core parameter information, and based on limit equilibrium theory, determine the initial sliding surface candidate range of steep valley slopes; based on the initial sliding surface candidate range and core parameter information, use particle swarm optimization algorithm to search for the most dangerous sliding surface; S3. Based on the information of the most dangerous sliding surface and core parameters, the slope area where the most dangerous sliding surface is located is divided into blocks using the limit equilibrium slice method to obtain the stress characteristic parameters of each block. S4. Based on the stress characteristic parameters and slope type of each block, the stability safety factor of the steep valley slope under single-point seismic action is calculated using the Yangbu method; based on the stability safety factor and the preset single-point safety factor range, the stability level of the steep valley slope under single-point seismic action is determined. S5. Determine the multi-point seismic comprehensive stability safety factor based on the slope stability level corresponding to different seismic action points and the influence weight of each action point; S6. Based on the comprehensive stability safety factor of multi-point earthquakes and the preset comprehensive safety factor range, determine the final safety evaluation results of steep slopes in river valleys under multi-point earthquakes.

[0018] In this invention, it is necessary to collect and determine basic data of the valley slope, such as topography, soil quality, rock structure, and groundwater conditions. This information is the basis for analyzing slope stability and can be obtained through field surveys, remote sensing data, drilling and sampling, etc. Based on the collected raw parameters, the slope type is determined, such as soil slope, rock slope, and its core parameters, such as slope gradient, slope length, and physical and mechanical properties of the soil or rock mass. These core parameters are helpful for further stability analysis. Limit equilibrium theory is commonly used for slope stability analysis, assuming that the slope will slide under a certain external force. Based on the slope type and core parameters, the possible candidate range of the initial sliding surface can be predicted. This refers to the surface on which the sliding surface is most likely to occur. The Particle Swarm Optimization (PSO) algorithm, a type of optimization algorithm that simulates the foraging behavior of bird flocks, is used to search for the optimal solution. Here, it is used to optimize the selection of the sliding surface, finding the most dangerous sliding surface—that is, the sliding surface that may cause the most severe damage in slope stability analysis. Through repeated iterations, the PSO algorithm can find the most suitable sliding surface. After determining the most dangerous sliding surface, the slope area where the sliding surface is located is divided into multiple strips using the limit equilibrium slice method. These strips are then subjected to mechanical analysis separately, with the stress conditions of each strip, such as soil gravity, friction, and internal stress, calculated individually. This strip division allows for a more precise analysis of the stability of each part. The Janbu method is a classic slope stability analysis method, commonly used to calculate the safety factor of slopes under different loads. In this step, the stability safety factor of a steep valley slope under a single-point earthquake is calculated. Earthquakes increase the sliding force of the slope, so the stability of the slope under earthquakes can be assessed by calculating the safety factor. The stability safety factor (FS) represents the degree of slope stability; the larger the FS value, the more stable the slope. Generally, a FS value greater than 1 indicates slope stability, while a value less than 1 indicates potential slope sliding. Based on the calculated stability safety factor and the preset safety factor range, the stability level of the slope under a single-point earthquake is determined. This level may be divided into different... The category is categorized as "stable," "unstable," or "hazardous." Since earthquakes can occur at different locations and times, this step considers the impact of multiple seismic action points. Each seismic action point has a different influence weight. Based on these weights and the corresponding stability level, a comprehensive stability safety factor under multi-point seismic action is calculated. This factor reflects the overall stability of the slope under multi-point seismic action. Based on the comprehensive stability safety factor under multi-point seismic action, combined with a preset safety factor range, the final safety assessment result is determined. This result determines the final stability assessment of steep valley slopes under multi-point seismic action. For example, if the safety factor is low, reinforcement or other preventative measures may be necessary.

[0019] In an optional embodiment, based on slope type and core parameter information, and based on limit equilibrium theory, the candidate range of the initial sliding surface for steep valley slopes is determined, including: If the slope type is a rock slope, the candidate range of the initial sliding surface is determined based on the rock mass integrity index and structural surface development characteristics in the core parameter information, as well as the mechanical critical conditions for rock mass failure in the limit equilibrium theory. If the slope type is a soil slope, the candidate range of the initial sliding surface is determined based on the soil cohesion and internal friction angle in the core parameter information, and the critical value of soil shear strength in the limit equilibrium theory. If the slope type is a mixed slope, the candidate range of the initial sliding surface is determined based on the regional distribution characteristics of rock and soil in the core parameter information, as well as the synergistic failure effect of different media in the limit equilibrium theory.

[0020] It should be noted that for rock slopes, core parameters typically include rock mass integrity indices, such as the degree of rock fragmentation, fracture development, and structural surface characteristics, including the direction, spacing, and density of fractures and joints. These parameters reflect the overall quality of the rock mass and the distribution of potential sliding surfaces. Limit equilibrium theory assumes that when a rock mass fails, it undergoes macroscopic sliding. For rock slopes, sliding usually occurs in areas where the rock mass is fractured or has a high concentration of fractures. According to limit equilibrium theory, the critical failure condition of a rock mass is closely related to the stress it bears and the distribution of fractures. When external forces (such as earthquakes or rainfall) act on the rock mass, fracture surfaces may become candidate areas for sliding surfaces. By analyzing the distribution and direction of fractures and the overall integrity of the rock mass, it is possible to... To initially determine the location and extent of the sliding surface; for soil slopes, key parameters include soil cohesion (c) and internal friction angle (φ); cohesion represents the adhesion within the soil, while the internal friction angle describes the friction between soil particles, both of which determine the soil's shear strength; in limit equilibrium theory, the key to slope stability lies in whether the soil's shear strength is sufficient to resist external loads, such as gravity and seismic forces; before sliding, the soil reaches its critical shear strength value; by calculating the soil's shear strength and combining it with the slope gradient, the candidate range of the sliding surface can be determined; typically, the sliding surface appears in areas with low shear strength or weak soil structure, especially when the soil cohesion is low or the friction angle is low; Mixed-material slopes refer to slopes composed of both rock and soil. Stability analysis of such slopes is more complex than that of single-material rock or soil slopes. Key parameters of mixed-material slopes include the distribution characteristics of both rock and soil regions. Typically, the rock region is harder, while the soil region is looser. Therefore, the sliding surface of a mixed-material slope may occur at the rock-soil interface or at a weak point in the soil region. In mixed-material slopes, rock and soil masses may slide synergistically or independently. The failure synergy effect in limit equilibrium theory considers the mutual influence between rock and soil regions. For example, soil sliding may be constrained by rock mass, and conversely, rock fracturing may affect soil stability. Therefore, the initial sliding surface candidate range needs to comprehensively consider the mechanical properties of both media. The sliding surface typically appears at the rock-soil interface or at the boundary between the two, where the failure synergy effect plays a crucial role.

[0021] In an optional embodiment, based on the initial candidate range of sliding surfaces and core parameter information, a particle swarm optimization algorithm is used to search for the most dangerous sliding surface, including: Based on the slope shear strength index and the boundary constraints of the initial sliding surface candidate range in the core parameter information, the initial position of the particles and the search range of the particle swarm optimization algorithm are determined. With the objective function of minimizing the slope stability safety factor, the particle swarm optimization algorithm iteratively updates the particle positions to screen out potential sliding surfaces that meet the constraints. The calculation formula for the particle swarm optimization algorithm update is as follows: ; ; in, Represents particles In the Iteration of each dimension The speed at this time Indicates the number of iterations. Indicates inertia weight, , Indicates the acceleration factor. , This represents a random number distributed between [0,1]. Particle swarm The historical best position at the next iteration. Particle swarm The global optimal position at the next iteration. Represents particles In the Iteration of each dimension The position at this time; Based on the stability-related parameters corresponding to the potential sliding surface and the criteria of limit equilibrium theory, the most dangerous sliding surface is determined.

[0022] It should be noted that slope shear strength is a key factor in assessing slope stability; shear strength determines whether soil or rock will slide under external forces; the initial slip surface candidate range is determined in the preliminary analysis, and these candidate areas may include weak layers, fracture surfaces, or stress concentration areas in the slope; these areas are considered potential sliding locations; in PSO, particles represent the potential location and morphology of the slip surface; the position of each particle in the search space, i.e., the morphology and depth of the slip surface, is determined by the slope shear strength index and the boundary constraints of the initial slip surface candidate range; the initial position of the particle swarm can be set according to the slope shear strength, such as the values ​​of cohesion and friction angle, and the boundary constraints of the slip surface candidate range; for example, if the candidate slip surface is on a weak surface of a soil layer, the particle position may initially be near that weak layer; the search range is determined by the physical properties of the slope and the initial slip surface candidate range; for rock, soil, or mixed slopes, the search range may include the entire slope or be limited to a portion of the slope; In this optimization process, minimizing the slope stability safety factor (FS) is the primary objective. The stability safety factor indicates whether the slope is in a safe state. The particle swarm optimization algorithm iteratively updates the positions of particles, gradually approaching the solution with the minimum safety factor. In each iteration, particles adjust their positions based on their current state and the objective function value, searching for potential slip surfaces that minimize the slope safety factor. The change in the position of each particle follows these rules: the particle's position moves closer to the optimal solution and the individual optimal state; during the update process, the particle's velocity and position are influenced by historical information; in the optimization process, constraints refer to the physical constraints of the slope in the stability analysis, such as the depth of the slip surface, the slope range, and the shear strength limitations of the soil or rock mass; particles can only move towards the optimal solution when the slope is in a safe state. A solution is considered valid only when these physical constraints are met. Once multiple potential sliding surfaces are found using the particle swarm optimization algorithm, the next step is to evaluate the stability of each surface. For each potential sliding surface, corresponding stability parameters need to be calculated, such as: sliding surface location: sliding surfaces are usually located in weak areas of soil or rock; shear strength and friction angle: these parameters affect the stability of the sliding surface; safety factor: each potential sliding surface has a calculated safety factor; limit equilibrium theory is used to determine whether a sliding surface will lead to slope instability. According to the theory, when the safety factor of the slope is less than 1, the sliding surface is considered dangerous and may cause a landslide. In practical applications, the most dangerous sliding surface usually refers to the sliding surface with the lowest safety factor among all candidate sliding surfaces, i.e., the sliding surface most prone to instability.

[0023] In an optional embodiment, based on the information of the most dangerous sliding surface and core parameters, the slope area where the most dangerous sliding surface is located is divided into blocks using the limit equilibrium slice method to obtain the stress characteristic parameters of each block, including: Based on the curvature variation characteristics of the most dangerous sliding surface and the slope distribution in the core parameter information, the number of blocks and the division boundaries are determined. The slope area where the most dangerous sliding surface is located is divided into several continuous blocks according to the boundary. The self-weight distribution characteristics, normal force characteristics and tangential force characteristics of the contact surface between the blocks are extracted to obtain the force characteristic parameters of each block.

[0024] It should be noted that curvature is an important parameter describing changes in the shape of the sliding surface; the most dangerous sliding surface is usually the location most prone to instability in the entire slope; curvature variation characteristics help understand the shape, degree of bending, and rate of change of the sliding surface; by analyzing curvature changes, the location characteristics of the sliding surface in the slope can be identified, such as whether there are obvious bending, depressions, or bulges; these changes often affect slope stability because different sliding surface shapes may correspond to different stress concentration areas; slope distribution refers to the slope angle at different heights and locations; in slope stability analysis, slope is one of the important factors affecting the stability of the sliding surface; areas with steeper slopes are often prone to landslides, therefore, slope distribution characteristics help identify areas that require focused analysis; based on the curvature variation characteristics of the sliding surface and the slope distribution, The slope can be divided into several sections. The number of sections and their boundaries usually depend on the complexity of the slip surface and the actual topography of the slope. If the slip surface changes drastically with large curvature variations, more sections may be needed. Conversely, if the slip surface is relatively gentle, fewer sections can be used. The boundaries are often based on changes in slope or curvature to ensure that the physical properties of each section are relatively uniform and can accurately reflect the stress state of the slope. After determining the number and boundaries, the slope is cut into multiple continuous sections. These sections can be considered as a small part of the slope, each with independent physical properties and stress state. Such division helps to accurately analyze the stability of different areas of the slope, especially in the case of complex terrain and slip surfaces, and can better capture the changes and effects in local areas. Self-weight refers to the force generated by gravity on each segment. The self-weight distribution characteristics of a segment include the mass distribution of each segment and the stress generated by its own weight. These stresses are crucial for analyzing slope stability because self-weight is often a major factor triggering landslides. The self-weight distribution of each segment can be correlated with its area, volume, density, and other factors, helping to understand the contribution of different areas to the stability of the entire sliding surface. The contact surface between segments refers to the contact area between adjacent segments. In landslide analysis, the force characteristics on these contact surfaces are very important because they directly affect the stability of the sliding surface. Normal force refers to the force perpendicular to the contact surface of the segments, usually representing the compressive force between the segments. Normal force is typically determined by the self-weight of adjacent segments and geological characteristics. The tangential force affects whether the contact surface will crack or slide; the tangential force refers to the force along the contact surface of the blocks, which is usually related to friction; the tangential force is the key factor in determining whether the blocks slide along the contact surface; in landslide analysis, excessive tangential force can lead to relative sliding between blocks, which may trigger a landslide; the stress characteristic parameters of each block refer to the characteristics of various forces borne by the block under its own weight, normal force, and tangential force; these parameters help to fully understand the stress state of each block during the landslide process; these stress characteristic parameters usually include the stress state, deformation degree, and possible sliding conditions of each block; by calculating these stress parameters, the contribution and influence of each block to the entire landslide event can be further determined, thereby assessing the stability of the entire slope.

[0025] In an optional embodiment, based on the stress characteristic parameters and slope type of each block, the stability safety factor of the steep valley slope under single-point seismic loading is calculated using the Yangbu method, including: The applicable correction coefficient for the Yangbu method is determined based on the slope type, and the force balance relationship between the blocks is constructed based on the normal force and tangential force in the force characteristic parameters of each block. By considering the influence of the direction and magnitude of the forces between the strips using the Yangbu method, the anti-slip torque and sliding torque of each strip are solved iteratively step by step. Based on the ratio of anti-sliding moment to sliding moment, the stability safety factor of steep valley slopes under single-point seismic action is obtained. The formula for calculating the stability safety factor under single-point seismic action is as follows: ; in, Indicates the first Safety factor for slope stability at each seismic action point This indicates the applicable correction factor for the Yangbu method. This represents the total number of slices obtained by the limit equilibrium slice method. Indicates the first The cohesive force of the medium at the sliding surface of each strip. Indicates the first The length of the sliding surface of each strip, Indicates the first The total normal force acting on each block Indicates the first Pore ​​water pressure at the sliding surface of each strip block Indicates the first The internal friction angle of the medium at the sliding surface of each strip block Indicates the first Anti-slip moment / sliding moment lever arm of each strip Indicates the first The weight of each block, Indicates the vertical seismic coefficient. Indicates the horizontal seismic coefficient. Indicates the first The inclination angle of the sliding surface of each strip, , Indicates the first The trigonometric function values ​​of the inclination angle of the sliding surface of each strip.

[0026] It should be noted that the correction factor is used to adjust the calculation results of the Yenbu method to better reflect actual conditions. Factors such as slope type, geological conditions, and hydrological environment will affect the selection of the correction factor. For example, in slopes with many weak layers, the correction factor may be larger to account for the influence of the weak layers. Depending on the type of slope, an appropriate correction factor can be selected through empirical formulas or experimental data to ensure that the stability assessment obtained by the Yenbu method is more accurate. In the Yenbu method, the slope is divided into several blocks, and each block bears a certain force; the normal force is vertical. Forces acting perpendicularly to the contact surface of the blocks are called forces, while tangential forces act along the direction of the contact surface. Normal forces are usually generated by the self-weight and compressive forces of adjacent blocks, while tangential forces are related to friction and directly affect the possibility of block sliding. Force balance refers to the interaction of forces between blocks, especially the balance between normal and tangential forces. To analyze the stability of the slope, it is necessary to establish the force balance relationship between blocks to ensure that all forces are in equilibrium. Based on this, the sliding force and anti-sliding force of each block can be calculated, thereby deriving the stability of the entire slope. Anti-slip moment and sliding moment are key parameters in the Yangbu method. Anti-slip moment refers to the anti-slip torque caused by the normal force and friction on the contact surface between the blocks; while sliding moment refers to the pushing torque caused by external forces such as gravity or earthquakes. In the Yangbu method, the direction and magnitude of the forces are crucial. The magnitude of the normal and tangential forces determines whether the blocks can slide, while their direction affects the sliding method—sliding along the sliding surface or along a specific direction. Therefore, the direction and magnitude of these forces must be considered when calculating the anti-slip moment and sliding moment. Iterative solution is an important step in the Yangbu method. Because the force relationships between the blocks can be complex, iterative methods are usually needed to gradually adjust the force parameters of each block to find an equilibrium solution. This process gradually approximates the true moment values, ultimately yielding accurate anti-slip moment and sliding moment. The ratio of anti-slip moment to sliding moment is used to... Key indicators for assessing slope stability include: if the resisting moment is greater than the sliding moment, the slope can resist sliding and is in a stable state; conversely, if the sliding moment is greater than the resisting moment, the slope is at risk of instability; the stability safety factor is a quantitative indicator of slope safety; generally, a safety factor greater than 1 indicates that the slope is stable, while a factor less than 1 indicates that the slope is at risk of landslide or instability; the safety factor can be obtained by calculating the ratio of the resisting moment to the sliding moment, and then the stability of the slope under seismic loading can be assessed; under single-point seismic loading, the stability of the slope is affected by the transmission of seismic waves; seismic force is usually an instantaneous and rapidly changing external force, so its impact on the slope needs to be specially considered; in this case, seismic loading will change the stress state of the blocks, which may lead to a larger sliding moment; therefore, when solving for the stability safety factor, the influence of seismic force needs to be considered, and the calculation results are usually adjusted through seismic simulation.

[0027] In an optional embodiment, a multi-point seismic comprehensive stability safety factor is determined based on the slope stability level corresponding to different seismic action points and the influence weight of each action point, including: Based on the source characteristics of each earthquake action point and the topographic sensitivity distribution characteristics of the slope, the influence weight corresponding to each earthquake action point is determined. The formula for calculating the influence weight of the earthquake action point is as follows: ; in, Indicates the first The influence weight of each earthquake action point This indicates the total number of points of action of the earthquake. Indicates the first Seismic intensity index at each seismic action point Indicates the first Propagation path coefficient of each earthquake action point Indicates the first Slope topographic sensitivity coefficient corresponding to each earthquake action point; Extract the stability safety factor associated with the slope stability level corresponding to each earthquake action point; Based on the weights of each influence and the corresponding stability safety coefficients, a multi-point earthquake comprehensive stability safety coefficient is obtained through a weighted fusion method.

[0028] It should be noted that the focal characteristics of an earthquake action point refer to factors such as the location of the earthquake's source, the distance from the epicenter to the slope, the focal depth, and the earthquake's intensity. Focal characteristics affect the propagation path, speed, and intensity of seismic waves, directly determining the degree of impact of each earthquake action point on the slope. For example, areas closer to the epicenter experience stronger seismic forces, thus their impact weight should be relatively higher. The topographic sensitivity of the slope refers to the response of the slope's geological and topographic features to seismic waves. Different terrains, such as steep slopes, gentle slopes, rock layer distribution, and soil types, will react differently to seismic waves. For example, steep slopes are generally more prone to landslides, and therefore, under the same seismic load, their stability may be more significantly affected. The impact weight is determined by comprehensively considering the focal characteristics and topographic distribution features to determine the magnitude of the impact of each earthquake action point on slope stability. This means that areas closer to the earthquake source or slopes more susceptible to earthquakes will have relatively higher weights. Slope stability levels are typically determined based on the safety factor of the slope under seismic loading. Different safety factor ranges correspond to different stability levels; for example, a safety factor greater than 1.5 indicates good stability, between 1.0 and 1.5 indicates potential risk, and less than 1.0 indicates instability and a high risk of landslides. A weighted fusion method combines the influence weight of each seismic action point with its corresponding stability safety factor to obtain a multi-point seismic comprehensive stability safety factor. Weighted fusion means that the influence of each seismic action point on slope stability is weighted according to its weight; the higher the weight of the action point, the greater its impact on the final comprehensive safety factor. The weighted fusion process essentially integrates the influence of all seismic action points to form a comprehensive stability assessment. The influence of different seismic sources can be adjusted through their weights to obtain a comprehensive safety factor reflecting slope stability. This method allows for a more accurate assessment of slope stability under multiple seismic loadings, especially considering the differences in seismic sources and slope locations.

[0029] In an optional embodiment, based on the source characteristics of each seismic action point and the topographic sensitivity distribution characteristics of the slope, the influence weight corresponding to each seismic action point is determined, including: Based on the characteristics of earthquake intensity and propagation path in the source characteristics, determine the degree of impact of the earthquake action point on the foundation of the slope; Based on the distribution of slope height and slope angle in the topographic sensitive distribution characteristics of slopes, the sensitivity coefficients of different areas of slopes to seismic action are determined. Based on the basic impact level and sensitivity coefficient, the impact weight corresponding to each earthquake action point is determined through comprehensive quantitative analysis.

[0030] It should be noted that earthquake intensity and propagation path characteristics are crucial factors determining the impact of earthquakes on slopes. Earthquake intensity typically refers to the magnitude of the earthquake or the intensity of seismic waves from the epicenter to the target area. Areas closer to the slope will experience stronger vibrations, while the intensity of seismic waves decreases as the epicenter moves further away from the slope. Therefore, earthquake intensity directly affects slope stability; the greater the magnitude, the greater the impact on the slope. Propagation path characteristics refer to the path of seismic wave propagation and the characteristics of different geological conditions and soil layers encountered during propagation. Seismic waves will be reflected and deflected due to different soil and rock structures during propagation. The intensity of seismic waves reaching a slope varies due to variations in propagation or attenuation. For example, the propagation effect of seismic waves through rocks and soil differs, leading to different seismic forces acting on slopes under different geological conditions. The shorter the path and the stronger the seismic wave, the greater the impact on the slope. Therefore, the degree of impact of the earthquake's action point on the slope's foundation is determined by a combination of the earthquake's magnitude and propagation path characteristics. The closer to the epicenter, the shorter the propagation path, and the greater the earthquake intensity, the greater the impact on the slope's foundation. The topographic sensitivity of a slope mainly refers to the response of the slope's shape and surface features to seismic waves. For example, slope height and slope angle distribution are two key factors affecting slope stability. The higher the slope, the greater the gravitational force it experiences, and the higher the risk of landslides or other instabilities during an earthquake. High slopes may generate significant inertial forces under seismic action, affecting slope stability. Therefore, the greater the slope height, the more sensitive it may be to seismic forces. Changes in slope angle directly affect slope stability. Steeper slopes are more prone to landslides or collapses under seismic action because they increase shear forces during earthquakes, making them more unstable. Gentler slopes are generally less affected by seismic waves. Therefore, areas with larger slope angles have a higher sensitivity to seismic forces. Combining slope height and slope angle distribution, we can obtain... Sensitivity coefficients vary across different areas of the slope. During design and assessment, areas with greater slope height and angle typically have higher sensitivity coefficients because these areas face a higher risk of stability issues during earthquakes. The degree of foundation impact and sensitivity coefficients are two factors used to assess slope stability from the perspectives of the earthquake source and slope topography, respectively. Through comprehensive quantitative analysis of these two factors, the final impact weight of each earthquake action point on the slope can be determined. The degree of foundation impact reflects the intensity and propagation path of the earthquake on the slope. If an earthquake action point, such as an area near the epicenter, has a strong earthquake intensity and a short propagation path, its foundation impact is greater, meaning its impact on the slope is also more significant. The sensitivity coefficient assesses the slope's response to seismic action based on its topographic features (slope height and slope angle). Areas with greater slope height and steeper slope angles have higher sensitivity coefficients, indicating that these areas are more sensitive to seismic action and have poorer stability. By combining these two factors, a weighted comprehensive analysis can determine the influence weight corresponding to each seismic action point. The higher the influence weight, the greater the impact of the seismic action point on the slope; conversely, seismic action points with lower influence weights have a smaller impact on the slope.

[0031] In an optional embodiment, it further includes: Based on the final safety assessment results and the engineering requirements of the slope, the risk level of the slope is determined; Based on the risk level and a pre-set risk management measures library, a corresponding slope reinforcement optimization scheme is matched.

[0032] It should be noted that the final safety assessment result is the result of a comprehensive analysis of slope stability; it typically involves evaluating factors such as the slope's geological conditions, seismic activity, rainfall impact, slope gradient, and soil structure. In this assessment, engineers consider the slope's historical stability, potential landslide or collapse risks, etc., to evaluate the slope's current safety status. The engineering usage requirements of a slope refer to the functions and tasks it needs to perform in actual engineering projects; for example, in cases where slopes serve as road, railway, or building foundations, they need to maintain sufficient stability to ensure the safe operation of these engineering facilities. The requirements for slope stability vary depending on the application. For example, slopes used for road construction may have higher stability requirements, while those in non-traffic areas may have relatively lower requirements. Based on safety assessment results and application needs, slopes can be classified into different risk levels. Risk levels are usually assessed based on the probability of slope instability, landslides, collapses, and other accidents, as well as the potential impact on engineering safety or the environment. Generally, risk levels can be divided into three categories: low, medium, and high. Slopes with higher risk levels require stricter control measures, while slopes with lower risk levels can be handled more leniently. Determining the risk level provides a basis for selecting subsequent reinforcement and optimization schemes. Different risk levels of slopes require intervention measures of varying intensities: Low-risk level: The slope has good stability and may not require extensive reinforcement measures, or only regular monitoring and some minor maintenance. Medium-risk level: The slope has some instability factors and may require some reinforcement measures, such as vegetation restoration and simple support structures. High-risk level: The slope has poor stability and significant risk, usually requiring more complex reinforcement methods, such as shotcrete, deep reinforcement, and drilling grouting. The risk management measures library refers to a collection of pre-prepared reinforcement schemes and preventative measures for different risk levels; this library contains various reinforcement measures applicable to different types of slopes. The database includes reinforcement technologies, optimization measures, and management methods. For example, for high-risk slopes, the database might include technologies to enhance soil stability, increase drainage system capacity, and install support structures. For low-risk slopes, simple monitoring and maintenance might be recommended. The process of matching reinforcement optimization schemes involves selecting the most suitable reinforcement scheme from the risk management measures database based on the slope's risk level. The selection of reinforcement schemes must consider not only the slope's safety but also factors such as cost, construction difficulty, and environmental impact. For example, if a slope has a high risk and is located in a busy traffic area, comprehensive reinforcement measures may be needed to ensure the slope's long-term stability. If the risk is low, only simple reinforcement or regular inspections may be required.

[0033] The specific embodiments of the invention have been described in detail above, but they are only examples, and this application is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications or substitutions to the invention are also within the scope of this application. Therefore, all equivalent changes, modifications, and improvements made without departing from the spirit and principles of this application should be covered within the scope of this application.

Claims

1. A safety evaluation method for the stability of a high and steep slope of a valley under multi-point earthquakes, characterized in that, include: Obtain the original parameter information of the steep slope of the valley, and based on the original parameter information, determine the slope type and core parameter information of the steep slope of the valley; Based on the slope type and core parameter information, and based on the limit equilibrium theory, the initial sliding surface candidate range of the steep valley slope is determined. Based on the initial candidate range of sliding surfaces and the core parameter information, the particle swarm optimization algorithm is used to search for the most dangerous sliding surface. Based on the most dangerous sliding surface and the core parameter information, the slope area where the most dangerous sliding surface is located is divided into blocks using the limit equilibrium slice method to obtain the stress characteristic parameters of each block; Based on the stress characteristic parameters and slope type of each block, the stability safety factor of the steep valley slope under single-point seismic action is calculated using the Yangbu method; based on the stability safety factor and the preset single-point safety factor range, the stability level of the steep valley slope under single-point seismic action is determined. Based on the slope stability level corresponding to different seismic action points and the influence weight of each action point, the multi-point seismic comprehensive stability safety factor is determined. Based on the comprehensive stability safety factor of the multi-point earthquake and the preset comprehensive safety factor range, the final safety evaluation result of the steep slope of the valley under multi-point earthquake is determined.

2. The safety evaluation method for the stability of a high and steep slope in a valley under multi-point earthquakes according to claim 1, characterized in that, Based on the slope type and core parameter information, and based on the limit equilibrium theory, the candidate range of the initial sliding surface for the steep valley slope is determined, including: If the slope type is a rock slope, the candidate range of the initial sliding surface is determined based on the rock mass integrity index and structural surface development characteristics in the core parameter information, as well as the mechanical critical conditions for rock mass failure in the limit equilibrium theory. If the slope type is a soil slope, the candidate range of the initial sliding surface is determined based on the soil cohesion and internal friction angle in the core parameter information, and the critical value of soil shear strength in the limit equilibrium theory. If the slope type is a mixed slope, the candidate range of the initial sliding surface is determined based on the characteristics of rock and soil regional distribution in the core parameter information, and the synergistic effect of failure of different media in the limit equilibrium theory.

3. The safety evaluation method for the stability of a high and steep slope in a valley under multi-point earthquakes according to claim 2, characterized in that, Based on the initial candidate range of sliding surfaces and the core parameter information, a particle swarm optimization algorithm is used to search for the most dangerous sliding surface, including: Based on the slope shear strength index and the boundary constraints of the initial sliding surface candidate range in the core parameter information, the initial particle position and search range of the particle swarm optimization algorithm are determined. With the minimization of the slope stability safety factor as the objective function, the particle swarm optimization algorithm iteratively updates the particle positions to screen out potential sliding surfaces that meet the constraints. Based on the stability-related parameters corresponding to the potential sliding surface and the discrimination criteria of the limit equilibrium theory, the most dangerous sliding surface is determined.

4. The safety evaluation method for the stability of steep valley slopes under multi-point earthquakes according to claim 3, characterized in that, Based on the information of the most dangerous sliding surface and the core parameters, the slope region where the most dangerous sliding surface is located is divided into blocks using the limit equilibrium slice method to obtain the stress characteristic parameters of each block, including: Based on the curvature change characteristics of the most dangerous sliding surface and the slope distribution in the core parameter information, the number of blocks and the division boundaries are determined. According to the defined boundary, the slope area where the most dangerous sliding surface is located is divided into several continuous blocks. The self-weight distribution characteristics, normal force characteristics and tangential force characteristics of the contact surface between the blocks are extracted to obtain the force characteristic parameters of each block.

5. A safety evaluation method for the stability of steep valley slopes under multi-point earthquakes, as described in claim 4, is characterized in that... Based on the stress characteristic parameters and slope type of each block, the stability safety factor of the steep valley slope under single-point seismic loading is calculated using the Yangbu method, including: The applicable correction coefficient of the spreading method is determined based on the slope type, and the force balance relationship between the blocks is constructed based on the normal force and tangential force in the force characteristic parameters of each block. By considering the influence of the direction and magnitude of the forces between the strips using the aforementioned method, the anti-slip torque and sliding torque of each strip are solved iteratively step by step. Based on the ratio of the anti-sliding moment to the sliding moment, the stability safety factor of the steep slope of the valley under single-point seismic action is obtained.

6. A safety evaluation method for the stability of steep valley slopes under multi-point earthquakes, as described in claim 5, is characterized in that... Based on the slope stability level corresponding to different seismic action points and the influence weight of each action point, a multi-point seismic comprehensive stability safety factor is determined, including: Based on the source characteristics of each earthquake action point and the topographic sensitivity distribution characteristics of the slope, the influence weight corresponding to each earthquake action point is determined. Extract the stability safety factor associated with the slope stability level corresponding to each earthquake action point; Based on the weights of each influence and the corresponding stability safety coefficients, a multi-point earthquake comprehensive stability safety coefficient is obtained through a weighted fusion method.

7. The safety evaluation method for the stability of a high and steep slope in a valley under multi-point earthquakes according to claim 6, characterized in that, Based on the source characteristics of each earthquake action point and the topographic sensitivity distribution characteristics of the slope, the influence weight corresponding to each earthquake action point is determined, including: Based on the characteristics of earthquake intensity and propagation path in the source characteristics, determine the degree of impact of the earthquake action point on the foundation of the slope; Based on the slope height and slope angle distribution in the topographic sensitive distribution characteristics of the slope, the sensitivity coefficients of different areas of the slope to seismic action are determined. Based on the aforementioned basic influence level and sensitivity coefficient, the influence weight corresponding to each seismic action point is determined through comprehensive quantitative analysis.

8. The safety evaluation method for the stability of a high and steep slope in a valley under multi-point earthquakes according to claim 7, characterized in that, Also includes: Based on the final safety assessment results and the engineering requirements of the slope, the risk level of the slope is determined; Based on the risk level and the preset risk management measures library, a corresponding slope reinforcement optimization scheme is matched.

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