Slag disposal site geological disaster dynamic assessment method, medium and equipment

Abstract

The invention discloses a method, medium and equipment for dynamically evaluating geological disasters of a waste slag field, and relates to the technical field of geological disaster evaluation.The method comprises the steps that a three-dimensional geological model of the waste slag field is constructed, topographic features of the waste slag field are extracted, and simulated rock-soil mechanical parameters are obtained; optimizing simulation rock-soil mechanical parameters by adopting an engineering analogy method and field measured data; based on the three-dimensional geologic model, defining a waste slag body sliding mode and an initial boundary condition, inputting the topographic features into Massflow software to carry out three-dimensional elastic-plastic fluid mechanics simulation, and calculating a waste slag body movement track according to optimized simulated rock-soil mechanics parameters; simulating the displacement, the accumulation range and the movement time of the waste slag body at different moments, and generating a spatio-temporal evolution diagram of the thickness, the speed and the influence range of the slag body; and performing dynamic risk assessment based on the spatio-temporal evolution diagram, and visually outputting a disaster risk area through a GIS platform. According to the method, the analysis efficiency and the early warning timeliness under the complex terrain are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of geological disaster assessment, and in particular to a method, medium and equipment for dynamic assessment of geological disasters in abandoned slag sites. Background Art

[0002] Waste dumps are an inevitable byproduct of construction projects, and their stability directly impacts construction safety and the surrounding environment. Excessive slag accumulation, steep slopes, or insufficient bearing capacity can lead to instability triggered by rainwater infiltration or vibrations (such as blasting or earthquakes), resulting in landslides and collapses. Waste dumps are often loose debris, which, when washed down by heavy rain, form a highly saturated mixed fluid that moves at high speed along gullies, forming debris flows. Subsidence can also occur due to compaction by the slag's own weight or the decomposition of humus within it, or subsidence caused by subsidence in underground goafs (such as mine waste dumps).

[0003] Traditional assessments of geological hazards at waste dumps rely heavily on manual on-site surveys and static mechanical analysis, resulting in low efficiency, insufficient accuracy, and an inability to dynamically predict the evolution of hazards. Existing numerical simulation methods (such as finite element analysis) can partially simulate geological hazards, but they lack the ability to deeply integrate high-resolution drone data and exhibit poor adaptability to complex terrain and geotechnical parameters. Furthermore, existing assessment methods struggle to achieve real-time integration of multi-source data and dynamic early warning, leading to delayed pre-disaster prevention measures and difficulty in controlling disaster losses. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that the existing spoil site geological hazard assessment method has poor adaptability to complex terrain and geotechnical parameters, and to propose a spoil site geological hazard dynamic assessment method, which includes the following steps: S1. Construct a three-dimensional geological model of the waste dump, extract the terrain characteristics of the waste dump, and obtain simulated geotechnical parameters; S2. Optimize the simulation geotechnical parameters using engineering analogy and field measured data; S3. Based on the 3D geological model, define the sliding mode and initial boundary conditions of the spoil body, input the terrain characteristics into Massflow software for 3D elastic-plastic fluid dynamics simulation, and calculate the movement trajectory of the spoil body based on the optimized simulated geotechnical parameters; S4. Based on the movement trajectory of the spoil body, simulate the displacement, accumulation range and movement time of the spoil body at different times, and generate a spatiotemporal evolution diagram of the spoil body thickness, speed and impact range; S5. Based on the spatiotemporal evolution diagram, dynamic risk assessment is carried out and the disaster risk areas are visualized and output through the GIS platform.

[0005] Furthermore, Based on the UAV remote sensing data, digital elevation model (DEM), and geological profile data of the waste dump, a three-dimensional geological model of the waste dump was constructed using the ArcGIS platform; The terrain characteristics of the waste dump are extracted based on the digital elevation model of the waste dump.

[0006] Furthermore, Geotechnical parameters include: cohesion, internal friction angle, effective stress on the sliding surface, pore water pressure, pore gas pressure, matrix suction and internal friction angle.

[0007] Furthermore, the terrain characteristics include the topography and the height of the landslide body.

[0008] Furthermore, the sliding modes of the waste body include: overall sliding type, rotation sliding type, and flow type.

[0009] Furthermore, the initial boundary conditions include the geometric range of the spoil body, the contact relationship between the spoil body and the underlying strata, material parameters, initial stress field, and initial velocity of the sliding body.

[0010] Furthermore, The Mohr-Coulomb model is used for elastic-plastic pressure-strain calculation and analysis. The shear strength of saturated soil is expressed by the following formula: , in, is the shear strength of saturated soil; is the normal stress acting on the shear surface; is the effective friction angle; c’ For effective cohesion; The shear strength of unsaturated soil is expressed by the following formula: , in, It represents the shear strength of unsaturated soil; For effective cohesion; is the effective friction angle; is the normal stress acting on the shear surface; is the pore water pressure; is the pore gas pressure; is the internal friction angle of matrix suction.

[0011] Furthermore, the shear stress on any surface at any point in the soil is Shear strength of soil In comparison, there are three situations: ① , indicating that the soil is not damaged; ② , indicating that the soil has been sheared; , indicating that the soil is in a state of ultimate equilibrium.

[0012] The present invention also proposes a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the above-mentioned dynamic assessment method for geological hazards in abandoned waste sites.

[0013] The present invention also proposes an electronic device, comprising a processor and a memory, wherein the processor and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes computer-readable instructions, and the processor is configured to call the computer-readable instructions to execute the above-mentioned dynamic assessment method for geological hazards in abandoned slag sites.

[0014] The beneficial effects brought about by the technical solution provided by the present invention are: The present invention constructs a three-dimensional geological model through multi-source data, optimizes geotechnical parameters, obtains terrain characteristics, uses Massflow software to perform three-dimensional elastic-plastic fluid mechanics simulation, and calculates the landslide motion trajectory based on the optimized simulated geotechnical parameters and the initial boundary conditions of the waste body, thus solving the problem of insufficient adaptability of geotechnical parameters. The displacement, accumulation range and movement time of waste soil under different working conditions are simulated, and dynamic disaster warning information is constructed by combining numerical simulation results with real-time monitoring data. By integrating high-resolution remote sensing data with dynamic numerical simulation technology, the present invention realizes the accurate assessment and real-time warning of geological hazards in waste sites, significantly improves the analysis efficiency and warning timeliness under complex terrain, and provides reliable technical support for engineering safety and disaster prevention and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a flow chart of a method for dynamically assessing geological hazards in a waste dump according to an embodiment of the present invention; Figure 2 The embodiment of the present invention is ~ Schematic diagram of the Mohr-Coulomb theory in a coordinate system; Figure 3 is the stress acting on the triangular element; Figure 4 is the Mohr stress circle of the triangular element; Figure 5 is a block diagram of an electronic device in an exemplary embodiment of the present invention; Figure 6 This is a diagram showing the results of a dynamic assessment of geological hazards at a waste dump in a study area using the method of an embodiment of the present invention. DETAILED DESCRIPTION

[0016] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0017] The flowchart of the method for dynamic assessment of geological hazards in a waste dump according to an embodiment of the present invention is as follows: Figure 1 , specifically including the following steps: S1. Construct a three-dimensional geological model of the waste dump, extract the terrain characteristics of the waste dump, and obtain simulated geotechnical parameters.

[0018] In this embodiment of the present invention, a 3D geological model of the spoil site is constructed using the ArcGIS platform, utilizing drone remote sensing data, a digital elevation model (DEM), and geological profile data. This 3D geological model integrates drone remote sensing data, the DEM, and geological profile information to create a 3D spatial model that accurately reflects the morphology and geological structure of the spoil mass. This model is used in subsequent sliding pattern identification, initial boundary condition definition, and 3D numerical simulations. It provides accurate geometric boundary, material distribution, and terrain input conditions for software such as MassFlow, thereby improving the accuracy and reliability of spoil mass trajectory prediction and risk assessment.

[0019] The topographic features of the spoil site were extracted based on the digital elevation model of the spoil site. These features included the terrain and landslide height, including slope, aspect, and curvature. The DEM data was resampled from the initial spatial resolution of 0.5 cm to 0.7 m and cropped to the size of the spoil site. The DEM raster data of the spoil site and the elevation raster data of the spoil body were converted to ASCII file format. ASCII files are a form of storing elevation point data in a matrix format, which contains information such as the elevation of the elevation point, the starting coordinates, and the grid spacing. These files are the terrain elevation information file z.txt and the landslide height file h.txt.

[0020] Geotechnical parameters include cohesion, internal friction angle, effective stress on the sliding surface, pore water pressure, pore gas pressure, matrix suction and internal friction angle. In the present invention, the numerical values ​​of the geotechnical parameters of the slope, retaining wall and building are referred to Table 1.

[0021] Table 1

[0022] S2. Use the engineering analogy method and field measured data to optimize the simulated geotechnical parameters. The optimized simulated geotechnical parameters are shown in Table 2.

[0023] Table 2

[0024] S3. Based on the three-dimensional geological model, the sliding mode and initial boundary conditions of the spoil body are defined, the terrain characteristics are input into the Massflow software for three-dimensional elastic-plastic fluid mechanics simulation, and the movement trajectory of the spoil body is calculated based on the optimized simulated geotechnical parameters.

[0025] The sliding modes of the spoil body include: overall sliding, rotational sliding, and flow. The initial boundary conditions include the geometric range of the spoil body, the contact relationship between the spoil body and the underlying strata, material parameters (including density, elastic modulus, Poisson's ratio, cohesion, friction angle, etc.), initial stress field, and the initial velocity of the sliding body (such as static or disturbed). These conditions are determined by field survey data, engineering analogy parameters, and terrain characteristics inverted from remote sensing DEM. Different sliding modes have different motion mechanisms and corresponding initial boundary conditions. For example, flow-type spoil bodies usually require a larger shear rate and disturbance, while rotational landslides require more complex contact boundaries and friction conditions. When constructing the model, the sliding type of the spoil body is determined based on its terrain characteristics, geotechnical parameters, and previous stability analysis, and the corresponding initial boundary conditions are set accordingly.

[0026] Soil shear strength is a crucial component of soil mechanics and is determined by a variety of factors, including soil composition, soil structure, stress history, stress levels within the soil, drainage conditions, and loading rate. The initial bearing capacity of the dam foundation, the earth pressure acting on the dam, and the stability of the dam are all related to soil shear strength. When shear failure occurs in soil, relative sliding occurs along a specific internal curved surface (the sliding surface), and the shear stress on this sliding surface is equal to the soil shear strength.

[0027] For saturated soil, the Mohr-Coulomb criterion is used to express the shear strength: , in, is the shear strength of saturated soil; is the normal stress acting on the shear surface; is the effective friction angle; For effective cohesion.

[0028] The failure envelope of the Mohr-Coulomb strength criterion for saturated soil is a straight line, which is the common tangent of a series of Mohr circles under failure conditions. The slope angle of the envelope is the effective internal friction angle. , and the vertical axis (shear stress ) is the effective cohesion ,like Figure 2 As shown, Figure 2 The embodiment of the present invention is ~ Schematic diagram of the Mohr-Coulomb theory in a coordinate system.

[0029] For unsaturated soils, the extended Mohr-Coulomb formula proposed by Fredlund is used to express the shear strength: , in, It represents the shear strength of unsaturated soil; For effective cohesion; is the effective friction angle; is the normal stress acting on the shear surface; is the pore water pressure; is the pore gas pressure; is the internal friction angle of matrix suction.

[0030] like Figure 3 and Figure 4 As shown, Figure 3 represents the stress acting on the triangular element, Figure 4 The Mohr stress circle representing the action of the triangular element is assumed to be: and , in the soil, it forms any angle with the maximum principal stress surface The stress in any direction can be expressed as follows: , , in, represents the shear stress, and represents the principal stresses in the horizontal and vertical directions, Indicates an angle.

[0031] The equation of the Mohr stress circle at any point in the soil is: , Stress analysis in soil can only calculate stresses perpendicular to the coordinate axes or principal stresses at each point, so it cannot directly determine whether a principal unit has failed. Further research is needed to directly express the Mohr-Coulomb failure theory using principal stresses, also known as the Mohr-Coulomb failure criterion, or the limit equilibrium condition for soil.

[0032] You can get: , , in, represents the internal friction angle, and c is the cohesion.

[0033] The above equation represents the principal stress relationship when the main unit reaches failure, which is the failure criterion of the Mohr-Coulomb theory. It is also the condition for the soil to reach the limit equilibrium state, which is called the limit equilibrium condition. To determine whether the soil is in the limit equilibrium state, it is necessary to know the principal stress and In fact, whether the limit equilibrium state is reached is determined by and The ratio of When is a fixed value, The smaller the soil is, the closer it is to destruction; on the contrary, when When is a fixed value, The larger it is, the closer the soil is to failure. In addition, under the ultimate equilibrium condition of the soil, the angle between the potential rupture surface and the maximum principal stress is: , This angle is the theoretical inclination angle formed by the slip surface.

[0034] At any point in the soil, the shear stress on any surface thereof is compared with the shear strength of the soil, and there may be three situations: ① , indicating that the soil is not damaged; ② , indicating that the soil has been sheared; , indicating that the soil is in a state of ultimate equilibrium; The soil failure condition is .

[0035] The Mohr-Coulomb model is an elastic-plastic model widely used in geotechnical engineering, which can effectively simulate the yield and failure behavior of materials. Based on the Mohr-Coulomb soil shear strength theory, the main factors affecting the displacement of the soil in the waste dump include the density of the slope and the building ( ), cohesion (c), internal friction angle ( ), bulk modulus (K), shear modulus (G), tensile strength ( ). Among them, the bulk modulus K and shear modulus G are determined by the following formula: , , Where E is the elastic modulus; is Poisson's ratio.

[0036] The motion state of the spoil body is obtained based on the optimized simulation geotechnical parameters and the initial boundary conditions of the spoil body, and the motion trajectory of the landslide body is analyzed from the motion state of the spoil body.

[0037] The Massflow operation steps include: 1. Run the Massflow program in GUI mode, select the new waste dump project file from the menu bar - File - and select the project save path; 2. Set basic parameters: including sliding body calculation block (1), calculation dimension (2D), initial fluid height (actual height), whether to consider erosion effect (no), density evolution (no), inertia force, shared memory distributed computing, distributed parallel computing, flux limiter, analysis type, etc.; 3. Terrain import and material setting: Add the terrain features obtained from external terrain files: terrain elevation information file z.txt and landslide height h.txt, select the z+h mode to allocate the geometric terrain and landslide; define the corresponding rock or fluid material type, physical friction model, material mechanics parameters, etc. 4. Output settings: Output time involves calculating the total time t (s), calculating the variable step length, output time interval, and calculating the kinematic variables of the accumulated thickness H (m) of the output spoil body; 5. Result review and post-processing: There are two ways to process the calculation results. One is to use Tecplot to generate cloud maps and extract node values. The other is to import the raster file into ArcGIS for post-processing, extract the node raster values ​​and overlay the hillshade map (remote sensing image) and output the evolution map. S4. Based on the movement trajectory of the spoil body, the displacement, accumulation range and movement time of the spoil body at different times are simulated to generate a spatiotemporal evolution diagram of the spoil body thickness, velocity and impact range.

[0038] Adaptive meshing and parallel computing improve simulation efficiency and generate spatiotemporal evolution diagrams of slag thickness, velocity, and impact range.

[0039] S5. Based on the spatiotemporal evolution diagram, combined with numerical simulation results and real-time monitoring data, dynamic risk assessment is carried out, and the disaster risk areas are visualized and output through the GIS platform.

[0040] Based on the spatiotemporal evolution diagram, dynamic risk assessment is conducted and yellow, orange and red multi-level warnings are designed. The thresholds of the multi-level warnings are set using the equal spacing method, and the spacing size is set according to the actual situation.

[0041] In an exemplary embodiment, a computer-readable storage medium is included, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned method for dynamically assessing geological hazards in a waste dump is implemented.

[0042] See also Figure 5 In an exemplary embodiment, an electronic device is also included, including at least one processor, at least one memory, and at least one communication bus.

[0043] Among them, a computer program is stored in the memory, and the computer program includes computer-readable instructions. The processor calls the computer-readable instructions stored in the memory through the communication bus to execute the above-mentioned dynamic assessment method for geological hazards in the waste dump.

[0044] To verify the effectiveness of the proposed method, experiments were conducted under the following conditions: an Intel Core i7 processor and a 64GB computer. The software platform used was Windows and ArcGIS 10.2. The high-resolution remote sensing imagery from a drone had a spatial resolution of 0.5 cm, and the digital elevation model was derived from the ALOS phased array, 1-band synthetic aperture radar (PALSAR) sensor, with a spatial resolution of 12.5 meters. For analysis, this resolution was resampled to 0.7 meters using bilinear interpolation.

[0045] refer to Figure 6 , Figure 6 This is a graph showing the results of a dynamic assessment of geological hazards at a waste dump site in the study area using the method of an embodiment of the present invention. The simulated source accumulation depth of the waste dump in the study area of ​​the embodiment of the present invention ranges from 0 to 16 meters, with the deepest accumulation depth occurring in the central region of the sliding body. After losing stability, the waste dump undergoes intense compression and collision with the sliding bed, forming a debris flow that fluidizes and rapidly moves southwestward. Within 0 to 30 seconds, the maximum longitudinal accumulation thickness during the forward movement of the sliding body can reach over 10 meters. After 120 seconds, the accumulation range at the leading edge of the waste dump has not expanded, the area with the deepest accumulation thickness has not changed significantly, and the remaining sliding body at the source location has also ceased movement, meaning the waste dump can be considered to have ceased movement at this point in time. Simulation results show that the waste dump has moved a total of 31.6 meters horizontally along its main profile, and the accumulation range on the plane of the waste dump is approximately 7,568.5 square meters. After measurement, the distance from the foot of the spoil body to the house is 54 meters. Therefore, when the spoil body is in an unstable state and a geological disaster occurs, the movement of the spoil body geological disaster will not threaten the two houses (lower left corner) closest to the downstream (west of the spoil body). At the same time, it shows that the geological disaster stability of the area where the houses are located is relatively good.

[0046] The above simulation experiments show that the present invention, by integrating high-resolution remote sensing data with dynamic numerical simulation technology, achieves accurate assessment and real-time warning of geological hazards in waste dumps, significantly improves analysis efficiency and warning timeliness under complex terrain, and provides reliable technical support for engineering safety and disaster prevention and control.

[0047] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for dynamic assessment of geological hazards in waste dumps, characterized in that: The following steps are involved: S1. Construct a three-dimensional geological model of the waste dump, extract the terrain characteristics of the waste dump, and obtain simulated geotechnical parameters; S2. Optimize the simulation geotechnical parameters using engineering analogy and field measured data; S3. Based on the 3D geological model, define the sliding mode and initial boundary conditions of the spoil body, input the terrain characteristics into Massflow software for 3D elastic-plastic fluid dynamics simulation, and calculate the movement trajectory of the spoil body based on the optimized simulated geotechnical parameters; S4. Based on the movement trajectory of the spoil body, simulate the displacement, accumulation range and movement time of the spoil body at different times, and generate a spatiotemporal evolution diagram of the spoil body thickness, speed and impact range; S5. Based on the spatiotemporal evolution diagram, dynamic risk assessment is carried out and the disaster risk areas are visualized and output through the GIS platform.

2. The method for dynamic assessment of geological hazards in a waste dump according to claim 1, characterized in that: Based on the UAV remote sensing data, digital elevation model, and geological profile data of the waste dump, a three-dimensional geological model of the waste dump was constructed using the ArcGIS platform; The terrain characteristics of the waste dump are extracted based on the digital elevation model of the waste dump.

3. The method for dynamic assessment of geological hazards in a waste dump according to claim 1, characterized in that: Geotechnical parameters include: cohesion, internal friction angle, effective stress on the sliding surface, pore water pressure, pore gas pressure, matrix suction and internal friction angle.

4. The method for dynamic assessment of geological hazards in a waste dump according to claim 1, characterized in that: Topographic characteristics include topography and landslide height.

5. The method for dynamic assessment of geological hazards in a waste dump according to claim 1, characterized in that: The sliding modes of the spoil body include: overall sliding type, rotation sliding type, and flow type.

6. The method for dynamic assessment of geological hazards in a waste dump according to claim 1, characterized in that: The initial boundary conditions include the geometric range of the spoil body, the contact relationship between the spoil body and the underlying strata, material parameters, initial stress field, and initial velocity of the sliding body.

7. The method for dynamic assessment of geological hazards in a waste dump according to claim 1, characterized in that: The Mohr-Coulomb model is used for elastic-plastic pressure-strain calculation and analysis. The shear strength of saturated soil is expressed by the following formula: ， in, is the shear strength of saturated soil; is the normal stress acting on the shear surface; is the effective friction angle; c' is the effective cohesion; The shear strength of unsaturated soil is expressed by the following formula: ， in, It represents the shear strength of unsaturated soil; For effective cohesion; is the effective friction angle; is the normal stress acting on the shear surface; is the pore water pressure; is the pore gas pressure; is the internal friction angle of matrix suction.

8. The method for dynamic assessment of geological hazards in a waste dump according to claim 1, characterized in that: Shear stress on any surface at any point in the soil Shear strength of soil In comparison, there are three situations: ① , indicating that the soil is not damaged; ② , indicating that the soil has been sheared; , indicating that the soil is in a state of ultimate equilibrium.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

10. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the processor and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes computer-readable instructions, and the processor is configured to call the computer-readable instructions to execute the method according to any one of claims 1 to 8.

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