A method and device for identifying the initiation of high-level rock landslide under earthquake action

Abstract

The present invention provides a method and device for identifying the initiation of high-level rock mass landslides under earthquake action, which relates to the field of geotechnical mechanics. The method comprises the following steps: S1: constructing a high-steep slope numerical model using a collection of exploration data; S2: applying a strong earthquake load to the bottom of the high-steep slope numerical model to obtain the velocity field and stress field of the high-steep slope numerical model; S3: analyzing the earthquake-induced cracking mechanism of the velocity field and stress field to construct a high-level rock mass fracture network; S4: dynamically searching for closed loops in the high-level rock mass fracture network; if no closed loop exists, returning to step S3; otherwise, proceeding to step S5; S5: analyzing the high-level rock mass sliding stability under strong earthquake action in the potential instability area defined by the closed loop to calculate the dynamic stability coefficient; if the dynamic stability coefficient is greater than a preset value, determining that the high-level rock mass landslide has started; otherwise, returning to step S3. The present invention systematically understands the initiation conditions of earthquake-induced high-level rock mass landslides from the perspective of mathematical mechanics, making the prediction of high-level rock mass landslides more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of rock and soil mechanics, and in particular to a method and device for identifying the initiation of high-position rock mass landslide under earthquake action. Background Art

[0002] High-lying rock masses are typically characterized by a high degree of weathering and dense joints and fissures. The ubiquitous presence of structural surfaces (or discontinuities) within the rock mass, such as joints, faults, bedding planes, and weak interlayers, forms a complex geometric network. This fracture network has a controlling influence on the mechanical properties of the rock mass, significantly affecting its strength, deformation behavior, and overall stability. Under strong earthquakes, the natural fracture network within the rock mass and the newly generated fractures induced by the earthquake interpenetrate, leading to localized instability and, in turn, large-scale high-lying rock mass landslides. This complex dynamic process demonstrates the crucial importance of analyzing the dynamic evolution of rock mass fractures under strong earthquakes and is of great significance for the prediction and prevention of high-lying rock mass landslides under earthquakes.

[0003] Currently, analytical methods for analyzing the evolution of rock mass fracture networks under earthquakes can be categorized into two areas: mathematics and mechanics. Mathematical methods based on geometric identification theory primarily reveal the underlying mechanisms and characteristics of rock mass landslides through the analysis and identification of geometric morphologies. This theory relies on the geometric properties of the rock mass's internal structure, such as the distribution and arrangement of faults, fractures, and rock layers, to infer its stability and failure modes. Its application primarily encompasses the following three areas:

[0004] The first application direction is the analysis of rock faults and fracture networks. By quantitatively analyzing the geometric characteristics of the fracture system within the rock mass (such as fracture density, direction, inclination, etc.), the weak surfaces and potential slip surfaces of the rock mass can be effectively identified, providing a scientific basis for the assessment of landslide risks.

[0005] The second application area is the analysis of rock mass fracture seepage networks. By analyzing fracture geometry (such as size, shape, and connectivity), we can identify seepage paths and flow distribution, and thus assess their impact on rock mass stability. The geometric characteristics of fracture seepage networks not only influence water migration but can also trigger changes in groundwater pressure, which can in turn trigger geological hazards such as rock collapse or landslides.

[0006] The third is the study of the correlation between geometric characteristics and collapse modes. By identifying and classifying the geometric characteristics of the rock mass, different types of collapse modes can be classified. The mechanical method based on the limit equilibrium method mainly simplifies the dynamic failure mode of high-level rock mass instability into a dynamic model controlled by steep cracks and sliding surfaces. This method uses a mass viscoelastic model to simulate the two main control structural surfaces, that is, a spring and damper are connected in parallel to simulate the dynamic response of the main control surface under seismic excitation. Furthermore, based on this dynamic model, a dynamic stability analysis model of the high-level rock mass is constructed considering factors such as the geometric shape, material properties and seismic excitation of the high-level rock mass. By solving this model, the dynamic response of the rock mass under earthquake action (such as displacement, acceleration and stress distribution) can be obtained, and the stress concentration on the main control structural surface and the possible sliding instability area can be further analyzed.

[0007] In summary, the current high-level rock mass landslide initiation identification based on rock mass fracture network analysis still has certain defects, which are mainly reflected in:

[0008] (1) Dynamic analysis of the evolution of rock mass fractures is insufficient. Existing studies have mostly focused on the analysis of static fracture networks, lacking in-depth research on the dynamic evolution of fractures. The dynamic effects of fracture expansion and closure on rock mass stability have not yet been fully revealed.

[0009] (2) Insufficient research on the coupling effect of multiple factors. The initiation of high-altitude rock mass landslides is usually the result of the combined effects of multiple factors, such as earthquakes, rainfall, and weathering. Existing methods mostly focus on the analysis of a single factor, and the study of the evolution of fracture networks and landslide mechanisms under the coupling of multiple factors is relatively weak.

[0010] (3) Lack of multi-level dynamic response analysis. In high-level rock masses, there are multiple rock layers and different types of structural surfaces, and their dynamic responses may be significantly different. Existing studies have failed to fully consider this multi-level effect. Summary of the Invention

[0011] In view of this, the purpose of the present invention is to provide a method and equipment for identifying the initiation of high-level rock landslides under earthquake action, which is used to solve the technical problems existing in the existing landslide initiation identification methods, such as insufficient dynamic analysis of the rock mass crack evolution process, insufficient research on multi-factor coupling effects, and lack of multi-level dynamic response analysis.

[0012] The present invention provides a method for identifying the initiation of a high-level rock mass landslide under an earthquake, comprising the following steps:

[0013] S1: Acquire exploration data sets based on geological surveys, UAV images, and laser point clouds, and construct a numerical model of the high and steep slope using the exploration data sets;

[0014] S2: Apply a strong seismic load to the bottom of the high-steep slope numerical model to simulate the propagation process of seismic waves and their dynamic response to the rock mass, and obtain the velocity field and stress field of the high-steep slope numerical model;

[0015] S3: Using the continuous-discontinuous numerical simulation method, the velocity field and stress field of the numerical model of the steep slope under strong earthquake are analyzed to analyze the earthquake-induced cracking mechanism and construct the high-level rock mass fracture network;

[0016] S4: Based on the geometric recognition theory, a loop analysis is performed on the high-level rock mass fracture network, and a closed loop in the high-level rock mass fracture network is dynamically retrieved. If there is no closed loop, the process returns to step S3; otherwise, the process proceeds to step S5;

[0017] S5: Based on the limit equilibrium method and the Newmark-β method, the sliding stability of the high-position rock mass under strong earthquake action is analyzed for the potential instability area defined by the closed loop, and the dynamic stability coefficient is calculated; if the dynamic stability coefficient is greater than the preset value, it is determined that the high-position rock mass landslide has started, otherwise return to step S3.

[0018] Preferred:

[0019] The numerical model of high and steep slopes reflects the slope geometry, rock mass bedding, joints and crack distribution.

[0020] Preferably, step S2 is specifically as follows:

[0021] S21: Apply a strong seismic load to the bottom of the high-steep slope numerical model to generate seismic waves in the high-steep slope numerical model. The seismic waves include horizontal and vertical components.

[0022] S22: Use the finite element method or discrete element method to solve the propagation process of seismic waves in the rock mass of the high and steep slope numerical model to obtain the dynamic response of the rock mass under the action of seismic waves;

[0023] S23: The rock mass in the high-steep slope numerical model is deformed by dynamic response, and the velocity field and stress field of the high-steep slope numerical model are calculated.

[0024] Preferred:

[0025] The expression of seismic wave is:

[0026]

[0027] in, is the horizontal component, is the vertical component, is the rock mass quality, and are the horizontal and vertical earthquake acceleration time histories respectively;

[0028]

[0029] in, is the azimuth, is the projection of the seismic wave in the east-west direction, is the projection of the seismic wave in the north-south direction, It is the projection of seismic waves in the vertical direction.

[0030] Preferably, step S3 is specifically as follows:

[0031] S31: Obtain the displacement change of the rock mass through the velocity field, obtain the stress change of the rock mass through the stress field, and construct the rock mass crack initiation discriminant equation based on the displacement change and stress change;

[0032] S32: Based on the rock mass crack initiation discriminant equation, the crack propagation process inside the rock mass is simulated by continuous-discontinuous numerical simulation method to construct the crack propagation equation;

[0033] S33: Based on the rock mass crack initiation discriminant equation and crack propagation equation, the crack propagation path, mutual interconnection and the generation state of new cracks in the rock mass are tracked to construct a high-level rock mass crack network.

[0034] Preferred:

[0035] The expression of the rock mass crack initiation discriminant equation is:

[0036]

[0037] in, and are the stress changes of rock mass under the action of seismic waves; and are the displacement changes of the rock mass in the normal and tangential directions respectively; and are the displacement thresholds when cracks occur in the rock mass; and are the tensile strength and shear strength of the rock mass, respectively; is the rock mass softening coefficient, When D is 0, it means that the rock mass is completely broken and the rock cracks are initiated and expanded; D is the damage factor, which reflects the damage degree of the rock cracks. The value range of D is 0 to 1. When D is 0, it means there is no damage; when D is 1, it means complete damage.

[0038] Preferably, step S4 is specifically as follows:

[0039] S41: Analyze the joint planes in the high-level rock mass fracture network through the geometric identification method, obtain the traces of each joint plane, determine the intersection positions and relative relationships between different traces through spatial geometric calculations, and construct an initial fracture network trace map of the high-level rock mass fracture network;

[0040] S42: removing overlapping, redundant or invalid nodes and edges from the initial fracture network trace graph, performing a directional operation on the edges, and obtaining a simplified fracture network trace graph;

[0041] S43: In the simplified fracture network trace diagram, searching and identifying a closed loop in the fracture network trace diagram by using the maximum right turn angle criterion. If there is no closed loop, proceed to step S44; otherwise, proceed to step S5.

[0042] S44: Based on the expansion of the crack, the geometric parameters of the crack in the high and steep slope numerical model are updated, and the process returns to step S3.

[0043] Preferably, step S5 is specifically as follows:

[0044] S51: For the potential instability area defined by the closed loop, the dynamic failure mode of high-level rock mass instability is simplified into the motion differential equation of the sliding body;

[0045] S52: Solve the differential equation of motion using the Newmark-β method to obtain the horizontal and vertical seismic forces on the sliding body during the earthquake duration;

[0046] S53: Based on the horizontal seismic force and the vertical seismic force, the dynamic stability coefficient of the sliding body under seismic excitation is calculated based on the limit equilibrium method; if the dynamic stability coefficient is greater than the preset value, it is determined that the high-level rock landslide has started; otherwise, according to the expansion of the crack, the geometric parameters of the crack in the high-steep slope numerical model are updated, and the process returns to step S3.

[0047] Preferred:

[0048] The differential equations of motion of the sliding body include: the differential equations of motion of the sliding body in the tangential direction s1 and normal direction n1 of the steep crack cs1 at the trailing edge, and the differential equations of motion of the sliding body in the tangential direction s2 and normal direction n2 of the sliding surface cs2;

[0049] The differential equations of motion of the sliding body in the tangential direction s1 and normal direction n1 of the trailing edge steep crack cs1 are expressed as follows:

[0050]

[0051] The differential equations of motion of the sliding body in the tangential direction s2 and normal direction n2 of the sliding surface cs2 are expressed as follows:

[0052]

[0053] in, 、 are the earthquake acceleration responses of the sliding body in the tangential s1 and normal n1 directions respectively; 、 are the seismic velocity responses of the sliding body in the tangential s1 and normal n1 directions, respectively; 、 are the seismic displacement responses of the sliding body in the tangential s1 and normal n1 directions, respectively; 、 are the earthquake acceleration responses of the sliding body in the tangential s2 and normal n2 directions respectively; 、 are the seismic velocity responses of the sliding body in the tangential s2 and normal n2 directions respectively; 、 are the seismic displacement responses of the sliding body in the tangential s2 and normal n2 directions respectively; is the rock mass quality; 、 、 and are the damping coefficients of the contact surface between the sliding body and the rock mass in the tangential and normal directions, respectively; 、 、 ,and are the stiffness coefficients of the contact surface between the sliding body and the rock mass in the tangential and normal directions, respectively; and are the earthquake acceleration responses of the sliding body in the horizontal and vertical directions respectively; α is the inclination angle of the steep crack at the trailing edge; β is the inclination angle of the sliding surface;

[0054] The expressions of horizontal seismic force and vertical seismic force are:

[0055]

[0056] in, F h (t) and F v (t) are the horizontal earthquake force and the vertical earthquake force, respectively. and are the shear forces of the slider in the tangential directions s1 and s2 respectively; and are the normal forces of the slider in the normal n1 and normal n2 directions respectively;

[0057] Dynamic stability coefficient The calculation formula is:

[0058]

[0059]

[0060]

[0061] Where A is the sliding surface area; B is the average width of the water-filled area of ​​the trailing steep fracture along the fracture strike; c is the sliding surface cohesion; φ is the internal friction angle of the sliding surface; W is the rock mass; V and U are the water pressure in the trailing steep fracture and the sliding surface water pressure, respectively; γ w is the density of water; h w is the water filling height of the trailing edge fissure; L is the length of the sliding surface.

[0062] A device for identifying the start of high-level rock mass landslide under earthquake action comprises: a processor and a storage medium; the processor loads and executes instructions and data in the storage medium to implement the method for identifying the start of high-level rock mass landslide under earthquake action.

[0063] The present invention has the following beneficial effects:

[0064] Starting from the continuous-discontinuous simulation method, through the analysis of the interaction between high-level rock mass and seismic loads, the seismic wave propagation effect and dynamic fracture effect of high-level rock mass are comprehensively considered. The dynamic rock fracture evolution process is quantified from a mathematical perspective combined with the geometric identification theory, targeting the destruction of the original structural surface of the high-level rock mass under seismic dynamic loading and the initiation, expansion and penetration of rock fracture cracks. On this basis, the sliding stability of the high-level rock mass under strong earthquake action is analyzed from a mechanical perspective combining the limit equilibrium method and the Newmark-β method, and the dynamic stability coefficient is calculated. The initiation of high-level rock mass landslide is judged based on the dynamic stability coefficient. From the perspective of mathematical mechanics, the initiation conditions of earthquake-induced high-level rock mass landslides are systematically understood, making the prediction of high-level rock mass landslides more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 This is a flow chart of a method according to an embodiment of the present invention;

[0066] Figure 2 This is a schematic diagram of the entire process of progressive destruction of rock mass fissures;

[0067] Figure 3 is a schematic diagram of the intersecting traces and corresponding edges;

[0068] Figure 4 This is a simplified fracture network trace diagram;

[0069] Figure 5 Search schematics for closed loops;

[0070] Figure 6 This is the structural diagram of the dynamic stability analysis model for sliding rock mass;

[0071] Figure 7This is the structural diagram of the numerical model of the high and steep slope;

[0072] Figure 8 This is a flow chart for identifying the initiation of high-level rock landslides under earthquake action;

[0073] Figure 9 This is a structural diagram of the device according to an embodiment of the present invention;

[0074] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0075] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0076] Reference Figure 1 The present application provides a method for identifying the initiation of high-level rock landslides under earthquake action, comprising the following steps:

[0077] S1: Acquire exploration data sets based on geological surveys, UAV images, and laser point clouds, and construct a numerical model of the high and steep slope using the exploration data sets;

[0078] As an example,

[0079] The numerical model of high and steep slopes reflects the slope geometry, rock mass bedding, joints and crack distribution.

[0080] S2: Apply a strong seismic load to the bottom of the high-steep slope numerical model to simulate the propagation process of seismic waves and their dynamic response to the rock mass, and obtain the velocity field and stress field of the high-steep slope numerical model;

[0081] As an example,

[0082] Step S2 is specifically as follows:

[0083] S21: Apply a strong seismic load to the bottom of the high-steep slope numerical model to generate seismic waves in the high-steep slope numerical model. The seismic waves include horizontal and vertical components.

[0084] Specifically, the expression of seismic wave is:

[0085] (1)

[0086] in, is the horizontal component, is the vertical component, is the rock mass quality, and are the horizontal and vertical earthquake acceleration time histories respectively;

[0087] Specifically, the horizontal component is composed of the projections of the EW (east-west) and NS (north-south) directions of the artificial seismic wave onto the high-level rock mass landslide analysis section, while the vertical component is represented by the UD (up-down) acceleration value. The horizontal component of the input seismic wave is projected onto the EW and NS seismic waves to obtain the horizontal and vertical earthquake acceleration time histories, respectively.

[0088] (2)

[0089] in, is the azimuth, is the projection of the seismic wave in the east-west direction, is the projection of the seismic wave in the north-south direction, It is the projection of seismic waves in the vertical direction.

[0090] S22: Use the finite element method or discrete element method to solve the propagation process of seismic waves in the rock mass of the high and steep slope numerical model to obtain the dynamic response of the rock mass under the action of seismic waves;

[0091] Specifically, by solving the seismic wave propagation equation and considering the propagation speed, propagation path, reflection and refraction effects of P and S waves, the dynamic response of the rock mass under the action of seismic waves is obtained. The equation of the seismic wave propagation process can be expressed as:

[0092] (3)

[0093] Where M is the mass matrix, C is the damping matrix, K is the stiffness matrix, 、 and S are acceleration, velocity, and displacement vectors, respectively.

[0094] S23: The rock mass in the high-steep slope numerical model is deformed by dynamic response, and the velocity field and stress field of the high-steep slope numerical model are calculated.

[0095] Specifically, based on the mechanical response characteristics of the numerical model of high and steep slopes under dynamic loading conditions, the rock deformation process was numerically simulated. The velocity field evolution law and stress field distribution characteristics of the slope rock mass were obtained by solving the constitutive equation. The dynamic response of the rock mass under the combined action of P waves and S waves was considered. The longitudinal vibration caused by P waves and the transverse vibration caused by S waves will lead to different deformation modes of the rock mass, and the stress, strain and crack extension responses of the rock mass were calculated.

[0096] S3: Using the continuous-discontinuous numerical simulation method, the velocity field and stress field of the numerical model of the steep slope under strong earthquake are analyzed to analyze the earthquake-induced cracking mechanism and construct the high-level rock mass fracture network;

[0097] As an example,

[0098] Step S3 is specifically as follows:

[0099] S31: Obtain the displacement change of the rock mass through the velocity field, obtain the stress change of the rock mass through the stress field, and construct the rock mass crack initiation discriminant equation based on the displacement change and stress change;

[0100] Specifically, by calculating the stress state of the rock mass under the action of earthquake motion, it can be determined whether cracks will initiate and expand due to stress exceeding a certain threshold. The whole process of progressive destruction of rock cracks is as follows: Figure 2 As shown;

[0101] The expression of the rock mass crack initiation discriminant equation is:

[0102] (4)

[0103] in, and are the stress changes of rock mass under the action of seismic waves; and are the displacement changes of the rock mass in the normal and tangential directions respectively; and are the displacement thresholds when cracks occur in the rock mass; and are the tensile strength and shear strength of the rock mass respectively; h is the calculation grid size; is the rock mass softening coefficient, When D is 0, it means that the rock mass is completely broken and the rock cracks are initiated and expanded; D is the damage factor, which reflects the damage degree of the rock cracks. The value range of D is 0 to 1. When D is 0, it means there is no damage; when D is 1, it means complete damage.

[0104] S32: Based on the rock mass crack initiation discriminant equation, the crack propagation process inside the rock mass is simulated by continuous-discontinuous numerical simulation method to construct the crack propagation equation;

[0105] Specifically, by establishing a crack expansion model, the interaction between dynamic load changes and cracks under earthquake action is considered. Crack expansion can be divided into two stages: initiation and expansion. In the initiation stage, when the stress reaches a certain threshold, cracks begin to appear and expand along the direction of maximum principal stress. In the expansion stage, cracks gradually expand along the structural weak plane of the rock mass and may intersect with adjacent cracks. The equation for crack expansion can be expressed as:

[0106] (5)

[0107] Where, 、 and are the acceleration, velocity and displacement of the rock mass, respectively.

[0108] S33: Based on the rock mass crack initiation discriminant equation and crack propagation equation, the crack propagation path, mutual interconnection and the generation state of new cracks in the rock mass are tracked to construct a high-level rock mass crack network.

[0109] Specifically, the geometric characteristic parameters of the expanded high-level rock mass fracture network, such as fracture length, density, and connectivity, can be extracted to provide data support for subsequent rock mass failure mode research and stability assessment.

[0110] S4: Based on the geometric recognition theory, a loop analysis is performed on the high-level rock mass fracture network, and a closed loop in the high-level rock mass fracture network is dynamically retrieved. If there is no closed loop, the process returns to step S3; otherwise, the process proceeds to step S5;

[0111] As an example,

[0112] Step S4 is specifically as follows:

[0113] S41: Analyze the joint planes in the high-level rock mass fracture network through the geometric identification method, obtain the traces of each joint plane, determine the intersection positions and relative relationships between different traces through spatial geometric calculations, and construct an initial fracture network trace map of the high-level rock mass fracture network;

[0114] Specifically, in professional terms, geometric identification is essentially based on the connectivity of fractures in high-level rock masses. Using spatial geometric calculations, the intersection positions and relative relationships between different fracture traces are determined, thereby preliminarily constructing the nodes and edges of the fracture network. The trace parameter equation is as follows:

[0115] (6)

[0116] Solving the simultaneous equations yields:

[0117] (7)

[0118] If both meet , , it means that the two traces intersect; if and Not satisfied at the same time , , which means that the two traces do not intersect. By performing the above operation on all intersecting traces of the fracture surface, including natural joints and rock mass boundaries, the trace intersection of the fracture surface can be completed, such as Figure 3 shown.

[0119] S42: removing overlapping, redundant or invalid nodes and edges from the initial fracture network trace graph, performing a directional operation on the edges, and obtaining a simplified fracture network trace graph;

[0120] Specifically, we perform “branch deletion” and remove overlapping, redundant or invalid nodes and edges according to the numerical characteristics and spatial positions of the intersection points to simplify the fracture network structure. On this basis, we perform directional operations on the formed edges. The results after “branch deletion” are as follows: Figure 4 shown.

[0121] S43: In the simplified fracture network trace diagram, searching and identifying a closed loop in the fracture network trace diagram by using the maximum right turn angle criterion. If there is no closed loop, proceed to step S44; otherwise, proceed to step S5.

[0122] Specifically, in the simplified fracture network trace diagram, arbitrarily select a corner point and its connected edges from the regularized fracture surface, first use the edge as the starting edge, rotate counterclockwise around the current corner point, find the next edge that forms the largest angle with the starting edge, and use it as the new starting edge to continue searching. Since each edge is bidirectional, the loop search is completed when all edges have been searched twice. According to the above search rules, two types of loops can be generated: loops with inner domains (inner loops) and loops with outer domains (outer loops). The type of loop can be determined by calculating the directed area of ​​the loop: when the directed area is positive, the loop is an inner loop; otherwise, it is an outer loop. The directed surface formed after the loop search is as follows. Figure 5 shown.

[0123] S44: Based on the expansion of the crack, the geometric parameters of the crack in the high and steep slope numerical model are updated, and the process returns to step S3.

[0124] Specifically, as the cracks expand, the geometric parameters of the cracks are dynamically updated, including the length, width, depth, and topological structure of the cracks. Through the topological relationship of the crack network, interconnected or intersecting cracks can be identified, and new crack paths can be generated based on the interactions during the expansion process. The topological structure of the crack network is updated using the following formula:

[0125] (8)

[0126] Where, for the updated fracture network; is the original fracture network; It is the expansion part of the crack.

[0127] S5: Based on the limit equilibrium method and the Newmark-β method, the sliding stability of the high-position rock mass under strong earthquake action is analyzed for the potential instability area defined by the closed loop, and the dynamic stability coefficient is calculated; if the dynamic stability coefficient is greater than the preset value, it is determined that the high-position rock mass landslide has started, otherwise return to step S3.

[0128] As an example:

[0129] Step S5 is specifically as follows:

[0130] S51: For the potential instability area defined by the closed loop, the dynamic failure mode of high-level rock mass instability is simplified into the motion differential equation of the sliding body;

[0131] Specifically, a dynamic stability analysis model of sliding rock mass is constructed by using the differential equation of motion of the sliding body. In this model, the mass-viscoelastic model is used to simulate the two main control structural surfaces. That is, by connecting the spring and the damper in parallel, the dynamic response behavior of the main control structural surface under seismic excitation is simulated. The high-level rock mass is regarded as a rigid body, and the horizontal and vertical seismic effects are comprehensively considered to construct the seismic dynamic stability analysis model of the high-level rock mass. The structure of the dynamic stability analysis model of sliding rock mass is as follows: Figure 6 shown.

[0132] The differential equations of motion of the sliding body include: the differential equations of motion of the sliding body in the tangential direction s1 and normal direction n1 of the steep crack cs1 at the trailing edge, and the differential equations of motion of the sliding body in the tangential direction s2 and normal direction n2 of the sliding surface cs2;

[0133] The differential equations of motion of the sliding body in the tangential direction s1 and normal direction n1 of the trailing edge steep crack cs1 are expressed as follows:

[0134] (9)

[0135] The differential equations of motion of the sliding body in the tangential direction s2 and normal direction n2 of the sliding surface cs2 are expressed as follows:

[0136] (10)

[0137] in, 、 are the earthquake acceleration responses of the sliding body in the tangential s1 and normal n1 directions respectively; 、 are the seismic velocity responses of the sliding body in the tangential s1 and normal n1 directions, respectively; 、 are the seismic displacement responses of the sliding body in the tangential s1 and normal n1 directions, respectively; 、 are the earthquake acceleration responses of the sliding body in the tangential s2 and normal n2 directions respectively; 、 are the seismic velocity responses of the sliding body in the tangential s2 and normal n2 directions respectively; 、 are the seismic displacement responses of the sliding body in the tangential s2 and normal n2 directions respectively; is the rock mass quality; 、 、 and are the damping coefficients of the contact surface between the sliding body and the rock mass in the tangential and normal directions, respectively; 、 、 ,and are the stiffness coefficients of the contact surface between the sliding body and the rock mass in the tangential and normal directions, respectively; and are the earthquake acceleration responses of the sliding body in the horizontal and vertical directions respectively; α is the inclination angle of the steep crack at the trailing edge; β is the inclination angle of the sliding surface;

[0138] S52: Solve the differential equation of motion using the Newmark-β method to obtain the horizontal and vertical seismic forces on the sliding body during the earthquake duration;

[0139] Specifically, the Newmark-β method is used to solve the above differential equation of motion to obtain the acceleration, velocity, and displacement response of the sliding rock mass under earthquake action. Combined with the solution of the dynamic motion equation of the sliding rock mass, the shear force and normal force of the sliding mass can be calculated as follows:

[0140] (11)

[0141] Furthermore, the expressions of horizontal seismic force and vertical seismic force are:

[0142] (12)

[0143] in, F h (t) and F v (t) are the horizontal earthquake force and the vertical earthquake force, respectively. and are the shear forces of the slider in the tangential directions s1 and s2 respectively; and are the normal forces of the slider in the normal n1 and normal n2 directions respectively;

[0144] S53: Based on the horizontal seismic force and the vertical seismic force, the dynamic stability coefficient of the sliding body under seismic excitation is calculated based on the limit equilibrium method; if the dynamic stability coefficient is greater than the preset value, it is determined that the high-level rock landslide has started; otherwise, according to the expansion of the crack, the geometric parameters of the crack in the high-steep slope numerical model are updated, and the process returns to step S3.

[0145] Specifically, the dynamic stability coefficient The calculation formula is:

[0146] (13)

[0147]

[0148] ;

[0149] Where A is the sliding surface area; B is the average width of the water-filled area of ​​the trailing steep fracture along the fracture strike; c is the sliding surface cohesion; φ is the internal friction angle of the sliding surface; W is the rock mass; V and U are the water pressure in the trailing steep fracture and the sliding surface water pressure, respectively; γ w is the density of water; h w is the water filling height of the trailing edge fissure; L is the length of the sliding surface.

[0150] As an example, a high-altitude rock mass project in a mountainous area is selected for research. According to step S1, a high-steep slope numerical model is established. Figure 7 As shown. Under natural conditions, the natural fracture network composed of joints and fissures cuts the slope rock mass into three independent sliding bodies. According to step S2, the stress concentration and crack expansion caused by the superposition of P waves and S waves are simulated. According to step S3, the fracture, connection and penetration of the high-level rock mass fracture network under seismic loads are studied. According to step S4, a dynamic loop search is performed on the high-level rock mass fracture network, and the sliding bodies formed by the closed loop are retrieved in real time, and finally 20 independent sliding bodies are formed. According to step S5, the dynamic stability coefficient of the independent sliding body is calculated to determine whether a landslide occurs. Finally, the whole process of the dynamic evolution of the high-level rock mass fracture network under earthquake action is obtained as shown in FIG. Figure 8 As shown in Figure 2, the high-level rock mass landslide initiated. Among them, some sliding bodies did not fail and landslide due to their high dynamic stability coefficient.

[0151] See Figure 9 , Figure 9 4 is a schematic diagram of the working of the hardware device of an embodiment of the present invention, wherein the hardware device specifically comprises: a device 401 for identifying the initiation of high-level rock landslide under earthquake action, a processor 402 and a storage medium 403.

[0152] A device 401 for identifying the start of a high-level rock mass landslide under an earthquake: The device 401 for identifying the start of a high-level rock mass landslide under an earthquake implements the method for identifying the start of a high-level rock mass landslide under an earthquake.

[0153] Processor 402: The processor 402 loads and executes the instructions and data in the storage medium 403 to implement the method for identifying the initiation of high-level rock mass landslide under earthquake action.

[0154] Storage medium 403: The storage medium 403 stores instructions and data; the storage medium 403 is used to implement the method for identifying the initiation of high-level rock landslide under earthquake action.

[0155] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or system. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or system comprising the element.

[0156] The serial numbers of the embodiments of the present invention are for descriptive purposes only and do not represent superiority or inferiority of the embodiments. In a unit claim that lists several means, several of these means may be embodied by the same item of hardware. The use of the terms first, second, and third, etc., does not denote any order and should be construed as identifiers.

[0157] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for identifying the initiation of high-level rock landslides under earthquake action, characterized in that: Including steps: S1: Acquire exploration data sets based on geological surveys, UAV images, and laser point clouds, and construct a numerical model of the high and steep slope using the exploration data sets; S2: Apply a strong seismic load to the bottom of the high-steep slope numerical model to simulate the propagation process of seismic waves and their dynamic response to the rock mass, and obtain the velocity field and stress field of the high-steep slope numerical model; S3: Using the continuous-discontinuous numerical simulation method, the velocity field and stress field of the numerical model of the steep slope under strong earthquake are analyzed to analyze the earthquake-induced cracking mechanism and construct the high-level rock mass fracture network; S4: Based on the geometric recognition theory, a loop analysis is performed on the high-level rock mass fracture network, and a closed loop in the high-level rock mass fracture network is dynamically retrieved. If there is no closed loop, the process returns to step S3; otherwise, the process proceeds to step S5; S5: Based on the limit equilibrium method and the Newmark-β method, the high-level rock mass sliding stability analysis under strong earthquake action is performed on the potential instability area defined by the closed loop, and the dynamic stability coefficient is calculated; if the dynamic stability coefficient is greater than a preset value, it is determined that the high-level rock mass landslide has started, otherwise the process returns to step S3; Step S5 is specifically as follows: S51: For the potential instability area defined by the closed loop, the dynamic failure mode of high-level rock mass instability is simplified into the motion differential equation of the sliding body; S52: Solve the differential equation of motion using the Newmark-β method to obtain the horizontal and vertical seismic forces on the sliding body during the earthquake duration; S53: Based on the horizontal seismic force and the vertical seismic force, the dynamic stability coefficient of the sliding body under seismic excitation is calculated based on the limit equilibrium method; if the dynamic stability coefficient is greater than the preset value, it is determined that the high-level rock landslide has started; otherwise, according to the expansion of the crack, the geometric parameters of the crack in the high-steep slope numerical model are updated, and the process returns to step S3.

2. The method for identifying the initiation of a high-level rock mass landslide under an earthquake according to claim 1, characterized in that: The numerical model of high and steep slopes reflects the slope geometry, rock mass bedding, joints and crack distribution.

3. The method for identifying the initiation of high-level rock landslide under earthquake action according to claim 1, characterized in that: Step S2 is specifically as follows: S21: Apply a strong seismic load to the bottom of the high-steep slope numerical model to generate seismic waves in the high-steep slope numerical model. The seismic waves include horizontal and vertical components. S22: Use the finite element method or discrete element method to solve the propagation process of seismic waves in the rock mass of the high and steep slope numerical model to obtain the dynamic response of the rock mass under the action of seismic waves; S23: The rock mass in the high-steep slope numerical model is deformed by dynamic response, and the velocity field and stress field of the high-steep slope numerical model are calculated.

4. The method for identifying the initiation of a high-level rock mass landslide under an earthquake according to claim 3, characterized in that: The expression of seismic wave is: in, is the horizontal component, is the vertical component, is the rock mass quality, and are the horizontal and vertical earthquake acceleration time histories respectively; in, is the azimuth, is the projection of the seismic wave in the east-west direction, is the projection of the seismic wave in the north-south direction, It is the projection of seismic waves in the vertical direction.

5. The method for identifying the initiation of high-level rock landslide under earthquake action according to claim 1, characterized in that: Step S3 is specifically as follows: S31: Obtain the displacement change of the rock mass through the velocity field, obtain the stress change of the rock mass through the stress field, and construct the rock mass crack initiation discriminant equation based on the displacement change and stress change; S32: Based on the rock mass crack initiation discriminant equation, the crack propagation process inside the rock mass is simulated by continuous-discontinuous numerical simulation method to construct the crack propagation equation; S33: Based on the rock mass crack initiation discriminant equation and crack propagation equation, the crack propagation path, mutual interconnection and the generation state of new cracks in the rock mass are tracked to construct a high-level rock mass crack network.

6. The method for identifying the initiation of a high-level rock mass landslide under an earthquake according to claim 5, characterized in that: The expression of the rock mass crack initiation discriminant equation is: in, and are the stress changes of rock mass under the action of seismic waves; and are the displacement changes of the rock mass in the normal and tangential directions respectively; and are the displacement thresholds when cracks occur in the rock mass; and are the tensile strength and shear strength of the rock mass, respectively; is the rock mass softening coefficient, When D is 0, it means that the rock mass is completely broken and the rock cracks are initiated and expanded; D is the damage factor, which reflects the damage degree of the rock cracks. The value range of D is 0 to 1. When D is 0, it means there is no damage; when D is 1, it means complete damage.

7. The method for identifying the initiation of high-level rock mass landslide under earthquake action according to claim 1, characterized in that: Step S4 is specifically as follows: S41: Analyze the joint planes in the high-level rock mass fracture network through the geometric identification method, obtain the traces of each joint plane, determine the intersection positions and relative relationships between different traces through spatial geometric calculations, and construct an initial fracture network trace map of the high-level rock mass fracture network; S42: removing overlapping, redundant or invalid nodes and edges from the initial fracture network trace graph, performing a directional operation on the edges, and obtaining a simplified fracture network trace graph; S43: In the simplified fracture network trace diagram, searching and identifying a closed loop in the fracture network trace diagram by using the maximum right turn angle criterion. If there is no closed loop, proceed to step S44; otherwise, proceed to step S5. S44: Based on the expansion of the crack, the geometric parameters of the crack in the high and steep slope numerical model are updated, and the process returns to step S3.

8. The method for identifying the initiation of high-level rock mass landslides under earthquake action according to claim 1, characterized in that: The differential equations of motion of the sliding body include: the differential equations of motion of the sliding body in the tangential direction s1 and normal direction n1 of the steep crack cs1 at the trailing edge, and the differential equations of motion of the sliding body in the tangential direction s2 and normal direction n2 of the sliding surface cs2; The differential equations of motion of the sliding body in the tangential direction s1 and normal direction n1 of the trailing edge steep crack cs1 are expressed as follows: The differential equations of motion of the sliding body in the tangential direction s2 and normal direction n2 of the sliding surface cs2 are expressed as follows: in, 、 are the earthquake acceleration responses of the sliding body in the tangential s1 and normal n1 directions respectively; 、 are the seismic velocity responses of the sliding body in the tangential s1 and normal n1 directions, respectively; 、 are the seismic displacement responses of the sliding body in the tangential s1 and normal n1 directions, respectively; 、 are the earthquake acceleration responses of the sliding body in the tangential s2 and normal n2 directions respectively; 、 are the seismic velocity responses of the sliding body in the tangential s2 and normal n2 directions respectively; 、 are the seismic displacement responses of the sliding body in the tangential s2 and normal n2 directions respectively; is the rock mass quality; 、 、 and are the damping coefficients of the contact surface between the sliding body and the rock mass in the tangential and normal directions, respectively; 、 、 ,and are the stiffness coefficients of the contact surface between the sliding body and the rock mass in the tangential and normal directions, respectively; and are the earthquake acceleration responses of the sliding body in the horizontal and vertical directions respectively; α is the inclination angle of the steep crack at the trailing edge; β is the inclination angle of the sliding surface; The expressions of horizontal seismic force and vertical seismic force are: in, F h (t) and F v (t) are the horizontal earthquake force and the vertical earthquake force, respectively. and are the shear forces of the slider in the tangential directions s1 and s2 respectively; and are the normal forces of the slider in the normal n1 and normal n2 directions respectively; Dynamic stability coefficient The calculation formula is: Where A is the sliding surface area; B is the average width of the water-filled area of ​​the trailing steep fracture along the fracture strike; c is the sliding surface cohesion; φ is the internal friction angle of the sliding surface; W is the rock mass; V and U are the water pressure in the trailing steep fracture and the sliding surface water pressure, respectively; γ w is the density of water; h w is the water filling height of the trailing edge fissure; L is the length of the sliding surface.

9. A device for identifying the initiation of high-level rock landslides under earthquake action, characterized by: include: Processor and storage medium; the processor loads and executes instructions and data in the storage medium to implement the method for identifying the start of high-level rock landslide under earthquake action as described in any one of claims 1 to 8.

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