A method for simulating a potential landslide movement process and a surge excited thereby

Abstract

The application discloses a kind of potential landslide movement process and its simulation method of surge excited, comprising: based on engineering geological survey, the profile and physical mechanics parameters of potential landslide are obtained;Based on unmanned aerial vehicle, the elevation topographic model of potential landslide is obtained;The profile and physical mechanics parameters of potential landslide are modelled, and the simulation landslide instability to large deformation evolution process is obtained;Based on the elevation topographic model, the calculation of the simulation landslide instability to large deformation evolution process is carried out, and the surge propagation process excited by landslide is obtained;Based on the preset software, the simulation of the simulation landslide instability to large deformation evolution process and the surge propagation process excited by landslide is carried out, and the simulation result graph of landslide surge is obtained.The application considers the evolution of sliding surface from stability to instability process of slope and the real migration process of landslide, and on this basis, the propagation law of surge is simulated, which is more in line with actual situation than pre-set sliding surface landslide surge simulation.

Description

Technical Field

[0001] This invention belongs to the field of numerical analysis of landslide surges, and in particular relates to a simulation method for the motion process of a potential landslide body and the surges it generates. Background Technology

[0002] The rapid development of hydropower and water conservancy projects has greatly promoted social progress, but it has also brought about some geological and environmental problems. The construction of reservoirs inevitably alters the original natural geological conditions of the reservoir banks, changing the physical and mechanical properties of the soil and rock slopes, thus affecting slope stability. Reservoir water has an infiltration and buoyancy effect on existing unstable geological bodies, landslides, and collapses on the reservoir banks. Furthermore, the operation of large hydropower stations causes water level fluctuations of up to tens of meters, adversely affecting the stability of the reservoir bank slopes. In addition, the potential earthquake threat in areas prone to strong earthquakes further increases the possibility of landslides and instability on the reservoir banks.

[0003] Unlike ordinary landslides, the instability of reservoir bank slopes, in addition to the disasters caused by the landslide itself, can also generate severe secondary disasters, such as triggering extremely destructive surges that can harm residents, houses, and infrastructure within the affected area on both sides of the reservoir. In particular, landslide surges near the dam area may threaten the safety of the dam. Therefore, conducting process simulations of landslide surges for potentially unstable reservoir bank slopes is of significant engineering importance. However, traditional landslide surge simulation methods generally artificially define a sliding surface on the slope, failing to consider the spontaneous evolution of the sliding surface and the actual movement of the landslide body during the slope's transition from stability to instability. This leads to discrepancies between the simulated landslide surges and the actual ones. Summary of the Invention

[0004] The purpose of this invention is to provide a simulation method for the movement process of a potential landslide and the surge waves it generates, in order to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides a method for simulating the movement process of a potential landslide and the surge waves it induces, comprising:

[0006] Based on engineering geological surveys, cross-sectional views and physical and mechanical parameters of potential landslide bodies are obtained;

[0007] Based on the terrain data acquired by the UAV, an elevation terrain model of the potential landslide body is obtained;

[0008] A model was established based on the cross-sectional view and physical and mechanical parameters of the potential landslide body to obtain a simulated evolution process from instability to large deformation of the landslide body;

[0009] The elevation and terrain model is calculated based on the simulated landslide instability to large deformation evolution process to obtain the propagation process of the surge wave triggered by the landslide.

[0010] Based on the preset software, the landslide surge process is simulated by analyzing the evolution process from instability to large deformation of the simulated landslide body and the propagation process of the surge wave triggered by the landslide, and the simulation result diagram of the landslide surge wave is obtained.

[0011] Preferably, the process of obtaining the cross-sectional view and physical and mechanical parameters of the potential landslide body includes:

[0012] Engineering geological surveys were conducted on the potential landslide bodies to obtain survey data;

[0013] Based on the survey data, the cross-sectional view and physical and mechanical parameters of the potential landslide body are obtained.

[0014] Preferably, the process of obtaining the elevation and terrain model of the potential landslide body includes:

[0015] Digital elevation topographic maps of the upstream and downstream areas of potential landslides were obtained using drones.

[0016] Based on photopolymerization stereoscopic modeling technology, the digital elevation topographic map is used to construct a model to obtain the elevation topographic model of the potential landslide body.

[0017] Preferably, the process of obtaining the simulated landslide instability to large deformation evolution includes:

[0018] The cross-sectional view and physical and mechanical parameters of the potential landslide body are calculated to obtain the mechanical model of the potential landslide body;

[0019] The mechanical model of the potential landslide was simulated based on the material point method to obtain the evolution process of the simulated landslide from instability to large deformation.

[0020] Preferably, obtaining the simulated landslide body's instability to large deformation evolution process further includes:

[0021] The landslide mass was simulated from instability to large deformation using a strain-softened Mohr-Coulomb model.

[0022] The constitutive relation of the strain-softened Mohr-Coulomb model is expressed as follows:

[0023]

[0024]

[0025]

[0026] Where c' represents cohesion, and c′ represents... r It is residual cohesion, c' p It is peak cohesion. It is the internal friction angle. It is the peak internal friction angle. It is the residual internal friction angle. It is a partial plastic strain invariant. It is the partial plastic strain tensor, where λ represents the strain softening rate. The larger the value, the faster the softening.

[0027] Preferably, after obtaining the simulated landslide body's instability to large deformation evolution process, the method further includes:

[0028] After calculating the instability to large deformation evolution process of the landslide body using the material point method, the velocity and displacement of the landslide body's centroid are derived, and the velocity and displacement of the landslide body's centroid are used as the initial conditions for the propagation process of the surge wave triggered by the landslide.

[0029] Preferably, the process of obtaining the propagation process of the landslide-induced surge includes:

[0030] A computational mechanics model of watershed landslide surge waves was established based on the elevation topography model and the simulated landslide instability to large deformation evolution process.

[0031] The propagation process of landslide-induced surge waves was obtained based on the smoothed fluid dynamics method and the computational mechanics model of the landslide surge waves in the domain.

[0032] Preferably, the process of establishing a computational mechanics model for watershed landslide surges includes:

[0033] Terrain units are obtained based on the elevation terrain model;

[0034] By setting the water level elevation data, fluid units are obtained;

[0035] Landslide elements were obtained based on the simulation of the evolution process from instability to large deformation of the landslide body;

[0036] The computational mechanics model of the landslide surge in the watershed is obtained based on the terrain unit, the fluid unit, and the landslide body unit.

[0037] Preferably, the physical and mechanical parameters include density, Poisson's ratio, elasticity model, cohesion, internal friction angle, water density, viscosity, and water level elevation.

[0038] The technical effects of this invention are as follows:

[0039] This invention considers the spontaneous evolution of the sliding surface and the actual movement of the landslide body during the process of slope stability to instability. Based on this, it simulates the propagation law of surge waves, which is more in line with the actual situation than the landslide surge wave simulation with a pre-set sliding surface. Attached Figure Description

[0040] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0041] Figure 1 This is a flowchart illustrating the simulation method for the movement process of a potential landslide body and the induction of swell waves in an embodiment of the present invention.

[0042] Figure 2 The velocity-time history curves during the motion evolution of the landslide body in this embodiment of the invention;

[0043] Figure 3 This is the displacement time history curve during the motion evolution of the landslide body in this embodiment of the invention;

[0044] Figure 4 This is a simulation result of landslide instability leading to large deformation in an embodiment of the present invention;

[0045] Figure 5 This is a diagram illustrating the propagation process of landslide surges in a watershed according to an embodiment of the present invention. Detailed Implementation

[0046] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0047] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0048] Example 1

[0049] like Figure 1 As shown, a simulation method for the movement process of a potential landslide and the surge waves it induces includes the following steps:

[0050] Step S1: Engineering geological investigation to obtain two-dimensional profiles and physical and mechanical parameters of potential landslide bodies;

[0051] Step S2: The UAV obtains digital elevation topographic maps 3 kilometers upstream and downstream of the potential landslide body and generates .stl files;

[0052] Step S3: Establish a computational mechanics model of the potential landslide body and use the material point method to simulate the evolution process from instability to large deformation of the landslide body;

[0053] Step S4: Establish a computational mechanics model of landslide surge in the watershed, and use smoothed fluid dynamics to calculate the propagation process of the surge triggered by the landslide;

[0054] Step S5: Use the ParaView open-source software to generate a simulation result diagram of the landslide surge.

[0055] This invention employs the Mohr-Coulomb model, which considers strain softening, to simulate the process of landslide movement from instability to large deformation. The peak strength of the landslide is obtained using triaxial geotechnical tests on undisturbed soil, and the residual strength is obtained using triaxial geotechnical tests on remolded soil. If undisturbed soil is difficult to obtain, and triaxial geotechnical tests are challenging to conduct to obtain the peak and residual strength of the landslide, it is recommended to use the limit equilibrium method to invert the mechanical parameters of the landslide under the critical state from stability to instability, and consider 80% of these parameters as the residual strength of the landslide after large deformation.

[0056] The strain-softening Moer-Coulomb constitutive relation of this implementation scheme is expressed as follows:

[0057]

[0058]

[0059]

[0060] Where c' represents cohesion, and c′ represents... r It is residual cohesion, c' p It is peak cohesion. It is the internal friction angle. It is the peak internal friction angle. It is the residual internal friction angle. It is a partial plastic strain invariant. It is the partial plastic strain tensor, where λ represents the strain softening rate. The larger the value, the faster the softening.

[0061] The instability to large deformation evolution process of the landslide body was calculated using the material point method, and the velocity and displacement of the landslide body's centroid were derived, which were used as the initial conditions for the next step of swell simulation. Figure 2-3 The velocity and displacement diagrams of the center of mass obtained using this implementation scheme are presented.

[0062] The computational mechanics model of landslide surge is divided into three attribute units. The first is the terrain unit, which is established from the .stl model obtained in step S2; the second is the fluid unit, whose distribution area in the three-dimensional terrain unit can be obtained by directly setting the water level elevation; and the third is the landslide body unit, which should specify its velocity and displacement, which are obtained from step S3.

[0063] This implementation plan uses the open-source post-processing software ParaView to generate the simulation results of the landslide instability to large deformation in step S3. Figure 4The results of the surge propagation in the watershed in step S4 are shown in the figure. Figure 5 ).

[0064] Example 2

[0065] A simulation method for the movement process of a potential landslide and the surge waves it induces, comprising the following steps:

[0066] Step S1: Engineering geological investigation to obtain two-dimensional profiles and physical and mechanical parameters of potential landslide bodies;

[0067] Step S2: The UAV obtains digital elevation topographic maps 3 kilometers upstream and downstream of the potential landslide body and generates .stl files;

[0068] Step S3: Establish a computational mechanics model of the potential landslide body and use the material point method to simulate the evolution process from instability to large deformation of the landslide body;

[0069] Step S4: Establish a computational mechanics model of landslide surge in the watershed, and use smoothed fluid dynamics to calculate the propagation process of the surge triggered by the landslide;

[0070] Step S5: Use the ParaView open-source software to generate a simulation result diagram of the landslide surge.

[0071] To further optimize the scheme, the material point method for the potential landslide body movement process was adopted using the open-source Anura3D platform, and the constitutive model adopted was the Mohr-Coulomb model that considers strain softening.

[0072] Further optimization of the scheme and the smooth hydrodynamic method for inducing swells were achieved using the open-source DualSPHysics platform.

[0073] Further optimization of the scheme resulted in the following material parameters for the slip source region: density, Poisson's ratio, elasticity model, cohesion, and internal friction angle.

[0074] The plan was further optimized by specifying the parameters of the river flow as water density, viscosity, and water level elevation.

[0075] The movement of the landslide body was simulated using the material point method, while the surge process it generated was simulated using the smoothed fluid dynamics method.

[0076] The instability to large deformation evolution process of the landslide body was calculated by the material point method, and the velocity and displacement of the center of mass of the landslide body were derived, which were used as the initial conditions for the next step of simulating the surge process using smooth hydrodynamics.

[0077] The Mohr-Coulomb model, which considers strain softening, was used to simulate the landslide's movement from instability to large deformation. The peak strength of the landslide was obtained using triaxial geotechnical tests on undisturbed soil, and the residual strength was obtained using triaxial geotechnical tests on remolded soil. If undisturbed soil is difficult to obtain, and triaxial geotechnical tests are not feasible to obtain the peak and residual strength of the landslide, it is recommended to use the limit equilibrium method to invert the mechanical parameters of the landslide under the critical state from stability to instability, and consider 80% of these parameters as the residual strength after large deformation of the landslide.

[0078] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for simulating the movement process of a potential landslide and the surge waves it induces, characterized in that, Includes the following steps: Based on engineering geological surveys, cross-sectional views and physical and mechanical parameters of potential landslide bodies are obtained; Based on the terrain data acquired by the UAV, an elevation terrain model of the potential landslide body is obtained; A model was established based on the cross-sectional view and physical and mechanical parameters of the potential landslide body to obtain a simulated evolution process from instability to large deformation of the landslide body; The elevation and terrain model is calculated based on the simulated landslide instability to large deformation evolution process to obtain the propagation process of the surge wave triggered by the landslide. Based on the preset software, the landslide surge process is simulated by analyzing the evolution process from instability to large deformation of the simulated landslide body and the propagation process of the surge wave triggered by the landslide, and the simulation result diagram of the landslide surge wave is obtained. The process of obtaining the simulated landslide body's instability to large deformation evolution specifically includes: The cross-sectional view and physical and mechanical parameters of the potential landslide body are calculated to obtain the mechanical model of the potential landslide body; The mechanical model of the potential landslide body was simulated based on the material point method to obtain the evolution process of the simulated landslide body from instability to large deformation. The landslide mass was simulated from instability to large deformation using a strain-softened Mohr-Coulomb model. After obtaining the simulated landslide body's instability to large deformation evolution process, the following is also included: After calculating the instability to large deformation evolution process of the landslide body using the material point method, the velocity and displacement of the center of mass of the landslide body are derived, and the velocity and displacement of the center of mass of the landslide body are used as the initial conditions for the propagation process of the surge wave triggered by the landslide. The specific process of obtaining the surge propagation triggered by the landslide includes: A computational mechanics model of watershed landslide surge waves was established based on the elevation topography model and the simulated landslide instability to large deformation evolution process. The propagation process of landslide-induced surge waves was obtained based on the smoothed fluid dynamics method and the computational mechanics model of the landslide surge waves in the domain.

2. The simulation method for the movement process of a potential landslide body and the induction of surge waves according to claim 1, characterized in that, The process of obtaining the profile and physical and mechanical parameters of a potential landslide includes: Engineering geological surveys were conducted on the potential landslide bodies to obtain survey data; Based on the survey data, the cross-sectional view and physical and mechanical parameters of the potential landslide body are obtained.

3. The simulation method for the movement process of a potential landslide body and the induction of surge waves according to claim 1, characterized in that, The process of obtaining the elevation and terrain model of the potential landslide body includes: Digital elevation topographic maps of the upstream and downstream areas of potential landslides were obtained using drones. Based on photopolymerization stereoscopic modeling technology, the digital elevation topographic map is used to construct a model to obtain the elevation topographic model of the potential landslide body.

4. The simulation method for the movement process of a potential landslide body and the induction of surge waves according to claim 1, characterized in that, Obtaining the simulated landslide body's instability to large deformation evolution process also includes: The constitutive relation of the strain-softened Mohr-Coulomb model is expressed as follows: in, It is cohesion. It is residual cohesion. It is peak cohesion. It is the internal friction angle. It is the peak internal friction angle. It is the residual internal friction angle. It is a partial plastic strain invariant. It is a partial plastic strain tensor. This represents the strain softening rate; the larger the value, the faster the softening.

5. The simulation method for the movement process of a potential landslide body and the induction of surge waves according to claim 1, characterized in that, The process of establishing a computational mechanics model for watershed landslide surges includes: Terrain units are obtained based on the elevation terrain model; By setting the water level elevation data, fluid units are obtained; Landslide elements were obtained based on the simulation of the evolution process from instability to large deformation of the landslide body; The computational mechanics model of the landslide surge in the watershed is obtained based on the terrain unit, the fluid unit, and the landslide body unit.

6. The simulation method for the movement process of a potential landslide body and the induction of surge waves according to claim 1, characterized in that, The physical and mechanical parameters include density, Poisson's ratio, elasticity model, cohesion, internal friction angle, water density, viscosity, and water level elevation.

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