A multi-scale numerical simulation method for slope instability mechanism of ductile shear band

Abstract

The application discloses a kind of containing ductile shear band slope instability mechanism multiscale numerical simulation method, it is related to geotechnical engineering geological disaster prevention technical field, comprising the following steps: step one, obtaining engineering survey data, and multiscale geometric model is constructed based on engineering survey data;Step two, the actual test data of ductile shear band material is obtained, and dynamic constitutive model is established based on micromechanics theory;Step three, set multiscale coupling condition and dynamic loading boundary, based on multiscale geometric model and dynamic constitutive model, carry out dynamic simulation calculation through numerical simulation platform, track the whole stage evolution process of ductile shear band from ductile deformation, brittle-ductile transition to brittle fracture, output the stress distribution data, strain evolution data and displacement field change data of each stage;It can significantly improve the simulation accuracy of ductile shear band slope instability mechanism, provide more reliable technical support for geological disaster prevention.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering geological disaster prevention and control technology, specifically to a multi-scale numerical simulation method for the instability mechanism of slopes with ductile shear zones. Background Technology

[0002] In the field of geological disaster prevention and control in geotechnical engineering, the existing technologies for studying the instability mechanism of slopes with ductile shear zones mainly rely on numerical simulation methods, such as the finite element method, discrete element method, material point method, etc., or combine them with limit equilibrium theory for stability analysis. These methods simulate the stress and strain response of slopes under loads such as gravity, earthquake, and rainfall by constructing geological models and inputting material parameters, thereby evaluating their stability. However, the failure process of ductile shear bands is significantly dynamic, and its evolution path covers three stages: ductile deformation, the transition between brittle and ductile, and brittle fracture. However, existing models mostly adopt static or quasi-static assumptions, ignoring the effects of time and loading rate, making it difficult to dynamically simulate the multi-stage evolution process of ductile shear bands from ductile deformation to brittle fracture. This leads to prediction errors in nonlinear softening behavior and critical conditions for slope instability, which in turn causes engineering safety risks, failure of disaster early warning, and ineffective remediation measures.

[0003] Therefore, in view of this, the present invention proposes a multi-scale numerical simulation method for the instability mechanism of slopes with ductile shear zones to make up for and improve the shortcomings of the existing technology. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a multi-scale numerical simulation method for the instability mechanism of slopes with ductile shear zones, thereby resolving the corresponding technical issues raised in the background section.

[0005] To achieve the above objectives, the technical solution adopted in this invention is: a multi-scale numerical simulation method for the instability mechanism of slopes with ductile shear zones, comprising the following steps: Step 1: Obtain engineering survey data and construct a multi-scale geometric model based on the engineering survey data. The multi-scale geometric model includes a macroscopic model of the slope and a microscopic model of the ductile shear zone embedded therein. Step 2: Obtain actual experimental data of ductile shear band materials, and establish a dynamic constitutive model based on micromechanics theory to describe the accumulation and development of damage during the transition from brittle to ductile and the brittle fracture stage. Step 3: Set multi-scale coupling conditions and dynamic loading boundaries. Based on the multi-scale geometric model and dynamic constitutive model, conduct dynamic simulation calculations through a numerical simulation platform to track the evolution of the ductile shear band from ductile deformation, brittle-ductile transition to brittle fracture, and output stress distribution data, strain evolution data and displacement field change data for each stage. Step 4: Based on the stress distribution data, strain evolution data, and displacement field change data output by the simulation calculation, identify the critical mechanical parameters and critical state of slope instability, and quantify the influence of the nonlinear softening behavior of the ductile shear zone on slope instability.

[0006] As a preferred option, In step one, The macroscopic model of the slope is matched to the actual dimensions and overall geological structure of the slope project; The microscopic model of the ductile shear band replicates the microscopic particle composition, pore distribution, and interfacial contact characteristics of the ductile shear band.

[0007] As a preferred method, the specific process for constructing a multi-scale geometric model is as follows: S101. Based on engineering survey data, construct a macroscopic model of a slope containing ductile shear zones using geographic information system technology, obtain microscopic images of the ductile shear zone area using computer tomography technology, and import them into digital image processing software for processing to extract particle boundary and microcrack information. S102. Based on the extracted information, a microscopic model of the ductile shear band is constructed using discrete element method (DEM) software to determine the size, shape, arrangement of particles, and initial distribution of microcracks. The average diameter of the particles is d, and the initial length of the microcracks is... ; S103. Embed the ductile shear band micro-model into the ductile shear band region in the slope macro-model. Define the ductile shear band region as a special element in the finite element software, and assign the mechanical parameters calculated from the ductile shear band micro-model to the special element. The mechanical parameters include the friction coefficient between particles. Elastic modulus E.

[0008] As a preferred approach, the specific process for establishing a dynamic constitutive model is as follows: S201. Based on micromechanics theory and actual experimental data, the dynamic constitutive model is established as follows: In the ductile deformation stage, a plastic constitutive model is adopted. This describes the mechanical behavior of the ductile shear band during the ductile deformation stage, where is... For stress, For total strain, Plastic strain; During the brittle-ductile transition and brittle fracture stages, a constitutive model based on continuum damage mechanics is adopted, defining the damage variable D and the effective stress of the material. ,in, , This indicates that the material is undamaged. This indicates that the material is completely destroyed; S202, By establishing a damage evolution equation This is used to describe the accumulation and development of damage in materials during the transition from brittle to ductile and the brittle fracture stage, in order to establish a complete dynamic constitutive model.

[0009] As a preferred method, the specific process for outputting stress distribution data, strain evolution data, and displacement field change data at each stage is as follows: S301. Set multi-scale coupling conditions, including displacement coupling and force coupling conditions, as follows: At the boundary between the macroscopic model of the slope and the microscopic model of the ductile shear zone, let the interface nodal displacement of the macroscopic model of the slope be... The average displacement of particles at the interface of the ductile shear band microstructure model is Then it requires ; Based on Newton's third law, let the forces exerted by the interface nodes of the macroscopic model of the slope on the microscopic model particles of the ductile shear zone be... The microscopic model particles of the ductile shear zone are subjected to the forces exerted by the interface nodes of the macroscopic model of the slope. ,but ; S302. Set dynamic loading boundaries, including load boundaries and displacement boundaries as follows: Obtain actual engineering data, and determine the type of load on the slope based on the actual engineering data. The load types include gravity load and seismic load. For gravity loads, the gravity f per unit volume is calculated based on the density ρ of the slope material and the gravitational acceleration g, using the following formula: The gravity per unit volume is applied as a volume force to the macroscopic model of the slope. For seismic loads, actual seismic records are acquired and used as input to convert them into nodal forces applied to the bottom boundary of the macroscopic slope model. The seismic acceleration time history is set as follows: Then nodal force , where m is the node mass; Based on the slope constraints, displacement boundaries are set, with the bottom of the slope designated as a fixed boundary. In the three-dimensional coordinate system, the displacement... The sides of the slope are set as free boundaries; S303. Import the multi-scale geometric model, dynamic constitutive model, multi-scale coupling conditions, and dynamic loading boundaries into the numerical simulation platform, and set the simulation time step. And the total simulation time T, where, C is the characteristic wave velocity of the material, and l is the unit size; S304. Start the simulation program to perform iterative calculations. At each time step, calculate the stress and strain relationship of the material according to the dynamic constitutive model, and update the stress, strain and displacement fields of the dynamic constitutive model by combining multi-scale coupling conditions and dynamic loading boundaries. S305. During the simulation, set the data output frequency and periodically output the stress distribution data, strain evolution data and displacement field change data of each stage of the ductile shear band. Data is output every n time steps, and the stress distribution data includes the stress tensor of each node. The strain evolution data includes the strain tensor of each node. The displacement field change data includes the displacement vectors of each node. .

[0010] As a preferred method, the specific process of quantifying the influence of the nonlinear softening behavior of the ductile shear band on slope instability is as follows: S401. Based on the stress distribution data, strain evolution data, and displacement field change data output by simulation calculations, the safety factor of the slope is calculated using the strength reduction method. The shear strength parameters of the material are reduced, and the reduction factor is calculated. Its formula is: , Where c is the cohesive force. It is the internal friction angle; Numerical simulations are performed based on the reduction results until the slope reaches instability. At this point, the reduction coefficient is... This is the safety factor of the slope; By continuously changing the reduction factor and conducting multiple simulations, the relationship curve between the safety factor and the reduction factor was plotted to determine the critical safety factor at which the slope becomes instable. ; By analyzing the stress distribution data output from the simulation calculation, the stress concentration areas in the slope are determined. When the stress in the stress concentration area reaches the material's strength limit, the slope is considered to have reached the critical stress state. When the slope top displacement is When the rate of change of the reduction factor exceeds a preset threshold, the slope is determined to be unstable. S402. Determine the softening modulus by the slope of the stress-strain curve during the softening stage. The softening modulus is a parameter used to describe the nonlinear softening behavior of the ductile shear band, and its formula is: ,in, and These represent the stress and strain increments during the softening stage, respectively. S403. By changing the softening parameters of the ductile shear band, multiple numerical simulations are performed to analyze the changes in the slope safety factor and critical displacement index. The softening parameters include the softening modulus and the cohesive softening coefficient. Softening coefficient of internal friction angle ; S404. The influence of the nonlinear softening behavior of the ductile shear zone on slope instability is quantified using linear regression. The relationship is as follows: , where a and b are regression coefficients.

[0011] Compared with existing technologies, the beneficial effects of this invention are as follows: By acquiring engineering survey data to construct a multi-scale geometric model, obtaining actual experimental data of ductile shear band materials, establishing a dynamic constitutive model based on micromechanics theory, setting multi-scale coupling conditions and dynamic loading boundaries, and conducting dynamic simulation calculations through a numerical simulation platform based on the multi-scale geometric model and the dynamic constitutive model, the invention tracks the entire evolution process of the ductile shear band from ductile deformation, brittle-ductile transition to brittle fracture, and outputs stress distribution data, strain evolution data, and displacement field change data for each stage. This allows for the identification of critical mechanical parameters and critical states of slope instability, quantification of the influence of nonlinear softening behavior of ductile shear bands on slope instability, and significantly improves the simulation accuracy of the instability mechanism of ductile shear band slopes, providing more reliable technical support for geological disaster prevention and control. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of a preferred embodiment of the present invention. Detailed Implementation

[0013] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] Embodiments of the present invention: Please refer to Figure 1 As shown, a multi-scale numerical simulation method for the instability mechanism of slopes with ductile shear zones includes the following steps: Step 1: Obtain engineering survey data and construct a multi-scale geometric model based on the engineering survey data. The multi-scale geometric model includes a macroscopic model of the slope and a microscopic model of the ductile shear zone embedded in it. Step 2: Obtain actual experimental data of ductile shear band materials, and establish a dynamic constitutive model based on micromechanics theory to describe the accumulation and development of damage during the transition from brittle to ductile and the brittle fracture stage. Step 3: Set multi-scale coupling conditions and dynamic loading boundaries. Based on the multi-scale geometric model and dynamic constitutive model, conduct dynamic simulation calculations through a numerical simulation platform to track the evolution of the ductile shear band from ductile deformation, brittle-ductile transition to brittle fracture, and output stress distribution data, strain evolution data and displacement field change data for each stage. Step 4: Based on the stress distribution data, strain evolution data, and displacement field change data output by the simulation calculation, identify the critical mechanical parameters and critical state of slope instability, and quantify the influence of the nonlinear softening behavior of the ductile shear zone on slope instability.

[0015] In step one, The macroscopic model of the slope is matched with the actual dimensions and overall geological structure of the slope project; The microscopic model of the ductile shear band replicates the microscopic particle composition, pore distribution, and interfacial contact characteristics of the ductile shear band.

[0016] The specific process of constructing a multi-scale geometric model is as follows: S101. Based on engineering survey data, construct a macroscopic model of a slope containing ductile shear zones using geographic information system technology, obtain microscopic images of the ductile shear zone area using computer tomography technology, and import them into digital image processing software for processing to extract particle boundary and microcrack information. S102. Based on the extracted information, a microscopic model of the ductile shear band is constructed using discrete element method (DEM) software to determine the size, shape, arrangement of particles, and initial distribution of microcracks. The average diameter of the particles is d, and the initial length of the microcracks is... ; S103. Embed the ductile shear band micro-model into the ductile shear band region in the slope macro-model. Define the ductile shear band region as a special element in the finite element software, and assign the mechanical parameters calculated from the ductile shear band micro-model to the special element. The mechanical parameters include the friction coefficient between particles. Elastic modulus E.

[0017] The specific process of establishing a dynamic constitutive model is as follows: S201. Based on micromechanics theory and actual experimental data, the dynamic constitutive model is established as follows: In the ductile deformation stage, a plastic constitutive model is adopted. This describes the mechanical behavior of the ductile shear band during the ductile deformation stage, where is... For stress, For total strain, Plastic strain; During the brittle-ductile transition and brittle fracture stages, a constitutive model based on continuum damage mechanics is adopted, defining the damage variable D and the effective stress of the material. ,in, , This indicates that the material is undamaged. This indicates that the material is completely destroyed; S202, By establishing a damage evolution equation This is used to describe the accumulation and development of damage in materials during the transition from brittle to ductile and the brittle fracture stage, in order to establish a complete dynamic constitutive model.

[0018] The specific process for outputting stress distribution data, strain evolution data, and displacement field change data at each stage is as follows: S301. Set multi-scale coupling conditions, including displacement coupling and force coupling conditions, as follows: At the boundary between the macroscopic model of the slope and the microscopic model of the ductile shear zone, let the interface nodal displacement of the macroscopic model of the slope be... The average displacement of particles at the interface of the ductile shear band microstructure model is Then it requires ; Based on Newton's third law, let the forces exerted by the interface nodes of the macroscopic model of the slope on the microscopic model particles of the ductile shear zone be... The microscopic model particles of the ductile shear zone are subjected to the forces exerted by the interface nodes of the macroscopic model of the slope. ,but ; S302. Set dynamic loading boundaries, including load boundaries and displacement boundaries as follows: Obtain actual engineering data and determine the type of load on the slope based on the actual engineering data. The load types include gravity load and seismic load. For gravity loads, the gravity f per unit volume is calculated based on the density ρ of the slope material and the gravitational acceleration g, using the following formula: The gravity per unit volume is applied as a volume force to the macroscopic model of the slope. For seismic loads, actual seismic records are acquired and used as input to convert them into nodal forces applied to the bottom boundary of the macroscopic slope model. The seismic acceleration time history is set as follows: Then nodal force , where m is the node mass; Based on the slope constraints, displacement boundaries are set, with the bottom of the slope designated as a fixed boundary. In the three-dimensional coordinate system, the displacement... The sides of the slope are set as free boundaries; S303. Import the multi-scale geometric model, dynamic constitutive model, multi-scale coupling conditions, and dynamic loading boundaries into the numerical simulation platform, and set the simulation time step. And the total simulation time T, where, C is the characteristic wave velocity of the material, and l is the unit size; S304. Start the simulation program to perform iterative calculations. At each time step, calculate the stress and strain relationship of the material according to the dynamic constitutive model, and update the stress, strain and displacement fields of the dynamic constitutive model by combining multi-scale coupling conditions and dynamic loading boundaries. S305. During the simulation, set the data output frequency and periodically output the stress distribution data, strain evolution data and displacement field change data of each stage of the ductile shear band. Data is output every n time steps, and the stress distribution data includes the stress tensor of each node. The strain evolution data includes the strain tensors at each node. The displacement field change data includes the displacement vectors of each node. .

[0019] The specific process of quantifying the influence of the nonlinear softening behavior of the ductile shear band on slope instability is as follows: S401. Based on the stress distribution data, strain evolution data, and displacement field change data output by simulation calculations, the safety factor of the slope is calculated using the strength reduction method. The shear strength parameters of the material are reduced, and the reduction factor is calculated. Its formula is: , Where c is the cohesive force. It is the internal friction angle; Numerical simulations are performed based on the reduction results until the slope reaches instability. At this point, the reduction coefficient is... This is the safety factor of the slope; By continuously changing the reduction factor and conducting multiple simulations, the relationship curve between the safety factor and the reduction factor was plotted to determine the critical safety factor at which the slope becomes instable. ; By analyzing the stress distribution data output from the simulation calculation, the stress concentration areas in the slope are determined. When the stress in the stress concentration area reaches the material's strength limit, the slope is considered to have reached the critical stress state. When the slope top displacement is When the rate of change of the reduction factor exceeds a preset threshold, the slope is determined to be unstable. S402. Determine the softening modulus by the slope of the stress-strain curve during the softening stage. The softening modulus is a parameter used to describe the nonlinear softening behavior of the ductile shear band, and its formula is: ,in, and These represent the stress and strain increments during the softening stage, respectively. S403. By changing the softening parameters of the ductile shear band, multiple numerical simulations were performed to analyze the changes in the slope safety factor and critical displacement index. The softening parameters include the softening modulus and the cohesive softening coefficient. Softening coefficient of internal friction angle ; S404. The influence of the nonlinear softening behavior of the ductile shear zone on slope instability is quantified using linear regression. The relationship is as follows: , where a and b are regression coefficients.

[0020] By acquiring engineering survey data to construct a multi-scale geometric model and obtaining actual experimental data of ductile shear zone materials, a dynamic constitutive model is established based on micromechanics theory. Multi-scale coupling conditions and dynamic loading boundaries are set. Based on the multi-scale geometric model and the dynamic constitutive model, dynamic simulation calculations are carried out through a numerical simulation platform to track the entire evolution process of the ductile shear zone from ductile deformation, brittle-ductile transition to brittle fracture. The stress distribution data, strain evolution data, and displacement field change data of each stage are output to identify the critical mechanical parameters and critical states of slope instability, and to quantify the impact of the nonlinear softening behavior of the ductile shear zone on slope instability. This can significantly improve the simulation accuracy of the instability mechanism of ductile shear zone slopes and provide more reliable technical support for geological disaster prevention and control.

[0021] The size of the interval and threshold is set to facilitate comparison. The size of the threshold depends on the amount of sample data and the number of bases set by those skilled in the art for each set of sample data; as long as it does not affect the ratio between the parameter and the quantized value.

[0022] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation. In the two embodiments provided in this application, it should be understood that the disclosed apparatus and system can be implemented in other ways; for example, the apparatus embodiments described above are merely illustrative, and the division of modules is merely a logical functional division. In actual implementation, there may be other division methods, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed; furthermore, the coupling or direct coupling or communication connection between the shown or discussed mutuals can be through some interfaces, and the indirect coupling or communication connection between the apparatus or modules can be electrical, mechanical or other forms. The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A multi-scale numerical simulation method for the instability mechanism of slopes with ductile shear zones, characterized in that, Includes the following steps: Step 1: Obtain engineering survey data and construct a multi-scale geometric model based on the engineering survey data. The multi-scale geometric model includes a macroscopic model of the slope and a microscopic model of the ductile shear zone embedded therein. Step 2: Obtain actual experimental data of ductile shear band materials, and establish a dynamic constitutive model based on micromechanics theory to describe the accumulation and development of damage during the transition from brittle to ductile and the brittle fracture stage. Step 3: Set multi-scale coupling conditions and dynamic loading boundaries. Based on the multi-scale geometric model and dynamic constitutive model, conduct dynamic simulation calculations through a numerical simulation platform to track the evolution of the ductile shear band from ductile deformation, brittle-ductile transition to brittle fracture, and output stress distribution data, strain evolution data and displacement field change data for each stage. Step 4: Based on the stress distribution data, strain evolution data, and displacement field change data output by the simulation calculation, identify the critical mechanical parameters and critical state of slope instability, and quantify the influence of the nonlinear softening behavior of the ductile shear zone on slope instability.

2. The multi-scale numerical simulation method for slope instability mechanism with ductile shear zone according to claim 1, characterized in that, In step one, The macroscopic model of the slope is matched to the actual dimensions and overall geological structure of the slope project; The microscopic model of the ductile shear band replicates the microscopic particle composition, pore distribution, and interfacial contact characteristics of the ductile shear band.

3. The multi-scale numerical simulation method for slope instability mechanism with ductile shear zone according to claim 2, characterized in that, The specific process of constructing a multi-scale geometric model is as follows: S101. Based on engineering survey data, construct a macroscopic model of a slope containing ductile shear zones using geographic information system technology, obtain microscopic images of the ductile shear zone area using computer tomography technology, and import them into digital image processing software for processing to extract particle boundary and microcrack information. S102. Based on the extracted information, a microscopic model of the ductile shear band is constructed using discrete element method (DEM) software to determine the size, shape, arrangement of particles, and initial distribution of microcracks. The average diameter of the particles is d, and the initial length of the microcracks is... ; S103. Embed the ductile shear band micro-model into the ductile shear band region in the slope macro-model. Define the ductile shear band region as a special element in the finite element software, and assign the mechanical parameters calculated from the ductile shear band micro-model to the special element. The mechanical parameters include the friction coefficient between particles. Elastic modulus E.

4. The multi-scale numerical simulation method for slope instability mechanism with ductile shear zone according to claim 3, characterized in that, The specific process of establishing a dynamic constitutive model is as follows: S201. Based on micromechanics theory and actual experimental data, the dynamic constitutive model is established as follows: In the ductile deformation stage, a plastic constitutive model is adopted. This describes the mechanical behavior of the ductile shear band during the ductile deformation stage, where is... For stress, For total strain, Plastic strain; During the brittle-ductile transition and brittle fracture stages, a constitutive model based on continuum damage mechanics is adopted, defining the damage variable D and the effective stress of the material. ,in, , This indicates that the material is undamaged. This indicates that the material is completely destroyed; S202, By establishing a damage evolution equation This is used to describe the accumulation and development of damage in materials during the transition from brittle to ductile and the brittle fracture stage, in order to establish a complete dynamic constitutive model.

5. The multi-scale numerical simulation method for slope instability mechanism with ductile shear bands according to claim 4, characterized in that, The specific process for outputting stress distribution data, strain evolution data, and displacement field change data at each stage is as follows: S301. Set multi-scale coupling conditions, including displacement coupling and force coupling conditions, as follows: At the boundary between the macroscopic model of the slope and the microscopic model of the ductile shear zone, let the interface nodal displacement of the macroscopic model of the slope be... The average displacement of particles at the interface of the ductile shear band microstructure model is Then it requires ; Based on Newton's third law, let the forces exerted by the interface nodes of the macroscopic model of the slope on the microscopic model particles of the ductile shear zone be... The microscopic model particles of the ductile shear zone are subjected to the forces exerted by the interface nodes of the macroscopic model of the slope. ,but ; S302. Set dynamic loading boundaries, including load boundaries and displacement boundaries as follows: Obtain actual engineering data, and determine the type of load on the slope based on the actual engineering data. The load types include gravity load and seismic load. For gravity loads, the gravity f per unit volume is calculated based on the density ρ of the slope material and the gravitational acceleration g, using the following formula: The gravity per unit volume is applied as a volume force to the macroscopic model of the slope. For seismic loads, actual seismic records are acquired and used as input to convert them into nodal forces applied to the bottom boundary of the macroscopic slope model. The seismic acceleration time history is set as follows: Then nodal force , where m is the node mass; Based on the slope constraints, displacement boundaries are set, with the bottom of the slope designated as a fixed boundary. In the three-dimensional coordinate system, the displacement... The sides of the slope are set as free boundaries; S303. Import the multi-scale geometric model, dynamic constitutive model, multi-scale coupling conditions, and dynamic loading boundaries into the numerical simulation platform, and set the simulation time step. And the total simulation time T, where, C is the characteristic wave velocity of the material, and l is the unit size; S304. Start the simulation program to perform iterative calculations. At each time step, calculate the stress and strain relationship of the material according to the dynamic constitutive model, and update the stress, strain and displacement fields of the dynamic constitutive model by combining multi-scale coupling conditions and dynamic loading boundaries. S305. During the simulation, set the data output frequency and periodically output the stress distribution data, strain evolution data and displacement field change data of each stage of the ductile shear band. Data is output every n time steps, and the stress distribution data includes the stress tensor of each node. The strain evolution data includes the strain tensor of each node. The displacement field change data includes the displacement vectors of each node. .

6. The multi-scale numerical simulation method for slope instability mechanism with ductile shear bands according to claim 5, characterized in that, The specific process of quantifying the influence of the nonlinear softening behavior of the ductile shear band on slope instability is as follows: S401. Based on the stress distribution data, strain evolution data, and displacement field change data output by simulation calculations, the safety factor of the slope is calculated using the strength reduction method. The shear strength parameters of the material are reduced, and the reduction factor is calculated. Its formula is: , Where c is the cohesive force. It is the internal friction angle; Numerical simulations are performed based on the reduction results until the slope reaches instability. At this point, the reduction coefficient is... This is the safety factor of the slope; By continuously changing the reduction factor and conducting multiple simulations, the relationship curve between the safety factor and the reduction factor was plotted to determine the critical safety factor at which the slope becomes instable. ; By analyzing the stress distribution data output from the simulation calculation, the stress concentration areas in the slope are determined. When the stress in the stress concentration area reaches the material's strength limit, the slope is considered to have reached the critical stress state. When the slope top displacement is When the rate of change of the reduction factor exceeds a preset threshold, the slope is determined to be unstable. S402. Determine the softening modulus by the slope of the stress-strain curve during the softening stage. The softening modulus is a parameter used to describe the nonlinear softening behavior of the ductile shear band, and its formula is: ,in, and These represent the stress and strain increments during the softening stage, respectively. S403. By changing the softening parameters of the ductile shear band, multiple numerical simulations are performed to analyze the changes in the slope safety factor and critical displacement index. The softening parameters include the softening modulus and the cohesive softening coefficient. Softening coefficient of internal friction angle ; S404. The influence of the nonlinear softening behavior of the ductile shear zone on slope instability is quantified using linear regression. The relationship is as follows: , where a and b are regression coefficients.

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