Three-dimensional numerical simulation calculation method for railway rockfall based on remote sensing technology

Abstract

The application discloses a kind of railway dangerous rock rockfall three-dimensional numerical simulation calculation methods based on remote sensing technology, comprising the following steps: obtaining target area remote sensing image and digital elevation data and engineering data;Build three-dimensional space physical motion analysis model;Calculate dangerous rock rockfall three-dimensional migration path;Determine dangerous rock rockfall prevention parameter;Dangerous rock rockfall three-dimensional simulation achievement display.The railway dangerous rock rockfall three-dimensional numerical simulation calculation method based on remote sensing technology of the application can accurately calculate the three-dimensional migration path of dangerous rock rockfall by remote sensing and GIS technology, obtain the prevention parameter of dangerous rock rockfall, and can be used to determine the protection range, strength and height of the blocking project, while realizing the three-dimensional simulation achievement display of dangerous rock rockfall, not only high accuracy, simple and feasible method, and low physical cost investment, strong engineering practicability.

Description

Technical Field

[0001] This invention belongs to the field of dangerous rockfall investigation and design, and specifically relates to a three-dimensional numerical simulation calculation method for dangerous rockfalls along railways based on remote sensing technology. Background Technology

[0002] Due to route selection constraints, mountain railways often face the risk of rockfall at tunnel entrances. Rockfalls possess high kinetic energy and destructive power, and can cause serious consequences if they land on the tracks or collide with high-speed trains. Rockfalls pose a significant threat to railway operational safety, necessitating systematic research and the development of targeted protective measures.

[0003] Numerical simulation of rockfall movement is a key and challenging research area, and a foundation for rockfall prevention design. The main parameters that need to be determined include movement path, bounce height, speed, and kinetic energy. Methods for determining these parameters include historical rockfall surveys, field tests, and rockfall movement calculations and simulations. Relying on historical rockfall surveys to determine threat zones has low accuracy, with large discrepancies between predicted and actual values, failing to meet practical engineering needs. Field tests are the best method for determining movement trajectories, but are often unavailable or too costly. Rockfall movement calculations and simulations still rely on manual calculations or Excel formulas, and are mostly two-dimensional models that can only calculate trajectories in a single direction, resulting in low efficiency and inability to meet current design requirements. Summary of the Invention

[0004] This invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a three-dimensional numerical simulation calculation method for railway rockfall based on remote sensing technology.

[0005] The technical solution of this invention is: a three-dimensional numerical simulation calculation method for railway rockfall based on remote sensing technology, comprising the following steps:

[0006] i. Acquire remote sensing images, digital elevation data, and engineering data for the target area S1

[0007] ii. Construct a three-dimensional spatial physical motion analysis model S2

[0008] iii. Calculate the three-dimensional migration path S3 of the falling rocks.

[0009] iv. Determine the parameters for preventing rockfalls and landslides, S4

[0010] v. Display of 3D simulation results of dangerous rockfalls (S5).

[0011] Furthermore, after obtaining high-resolution remote sensing image data, high-precision digital elevation data, and railway engineering data for the target area in step i, it is also necessary to obtain slope and rockfall parameters.

[0012] Furthermore, the target area includes the area where dangerous rocks and rocks develop and the area affected by dangerous rocks and rocks.

[0013] Furthermore, step ii involves preprocessing high-resolution remote sensing image data, high-precision digital elevation data, and railway engineering data to construct a three-dimensional spatial physical motion analysis model.

[0014] Furthermore, step iii calculates the three-dimensional migration path of the falling rocks, including the following processes:

[0015] a. Start simulation

[0016] b. Perform flight / bounce calculations

[0017] c. Determine whether the dangerous rockfall has been damaged. If the dangerous rockfall has been damaged, return to step a to continue the calculation; if the dangerous rockfall has not been damaged, continue to step d.

[0018] d. Determine if the rockfall has stopped. If it has stopped, end the process; if it has not stopped, continue with step e.

[0019] e. Determine whether the falling rocks have turned into rolling rocks. If the falling rocks have not turned into rolling rocks, return to step a to continue the calculation; if the falling rocks have turned into rolling rocks, continue to step f.

[0020] f. Perform rolling calculations

[0021] g. Determine if the rockfall has stopped. If it has stopped, end the process; if it has not stopped, continue with step h.

[0022] h. Determine whether the falling rocks have changed to flight. If the falling rocks have not changed to flight, return to step f to continue the calculation; if the falling rocks have changed to flight, return to step a to continue the calculation.

[0023] Furthermore, the parameters for preventing rockfalls in step iv include the protection range, protection strength, and protection height of the retaining structure.

[0024] Furthermore, determining the protection range includes the following steps:

[0025] First, obtain the three-dimensional spatial physical motion analysis model of step ii and the three-dimensional migration path of the falling rocks in step iii;

[0026] Then, determine the spatial relationship between the trajectory of the falling rocks and the railway engineering;

[0027] Finally, the protection zone of the railway is determined in order to intercept falling rocks.

[0028] Furthermore, determining the protection strength includes the following steps:

[0029] First, the three-dimensional migration path equation of the falling rocks is obtained;

[0030] Then, the velocity of the falling rocks at different trajectory points is obtained;

[0031] Finally, the impact energy is obtained through the kinetic energy theorem. The impact energy is used to determine the protective strength of the barrier project, and the protective strength is greater than the impact energy.

[0032] Furthermore, determining the protection height includes the following steps:

[0033] First, the three-dimensional spatial physical motion analysis model was obtained;

[0034] Then, using GIS technology, the vertical height difference between the trajectory points of the three-dimensional migration path of the falling rocks and their respective cell is calculated to obtain the bounce height of the falling rocks.

[0035] Finally, the protective height of the barrier project was determined, and the protective height is higher than the bounce height of the falling rocks.

[0036] Furthermore, step v showcases the results of the 3D simulation of the falling rocks, including a 3D visualization of the rockfall migration path; a color-stretched display of impact energy, velocity, and bounce height values; and a dynamic display of the 3D motion trajectory.

[0037] The present invention provides a three-dimensional numerical simulation calculation method for railway rockfall based on remote sensing technology. This method can accurately calculate the three-dimensional migration path of rockfall using remote sensing and GIS technology, obtain rockfall prevention parameters, and determine the protection range, strength and height of barrier projects. It can also realize the display of three-dimensional simulation results of rockfall. The method is not only highly accurate and simple, but also has low material cost and strong engineering applicability. Attached Figure Description

[0038] Figure 1 This is a flowchart of the method of the present invention;

[0039] Figure 2 This is a flowchart of the calculation process for the three-dimensional migration path of falling rocks along railways in this invention;

[0040] Figure 3 This is a calculation path diagram for the rolling of falling rocks along railways in this invention;

[0041] Figure 4 This is a diagram illustrating the determination of the movement state of falling rocks along railway tracks in this invention.

[0042] Figure 5 This is a diagram illustrating the determination of the damage state (without joints or fissures) of dangerous rocks and falling rocks along railways in this invention.

[0043] Figure 6This is a diagram for determining the damage state (with joints and fissures) of dangerous rocks and falling rocks on railways in this invention. Detailed Implementation

[0044] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0045] like Figures 1-6 As shown, a three-dimensional numerical simulation calculation method for railway rockfall based on remote sensing technology includes the following steps:

[0046] i. Acquire remote sensing images, digital elevation data, and engineering data for the target area.

[0047] ii. Construct a three-dimensional spatial physical motion analysis model

[0048] iii. Calculate the three-dimensional migration path of falling rocks.

[0049] iv. Determine parameters for preventing rockfalls.

[0050] v. Display of 3D simulation results of dangerous rockfall.

[0051] After obtaining high-resolution remote sensing image data, high-precision digital elevation data, and railway engineering data for the target area in step i, it is also necessary to obtain slope and rockfall parameters.

[0052] The target area includes the area where dangerous rocks and rocks are developed and the area affected by dangerous rocks and rocks.

[0053] Step ii involves preprocessing high-resolution remote sensing image data, high-precision digital elevation data, and railway engineering data to construct a three-dimensional spatial physical motion analysis model.

[0054] Step iii calculates the three-dimensional migration path of the falling rocks, including the following processes:

[0055] a. Start simulation

[0056] b. Perform flight / bounce calculations

[0057] c. Determine whether the dangerous rockfall has been damaged. If the dangerous rockfall has been damaged, return to step a to continue the calculation; if the dangerous rockfall has not been damaged, continue to step d.

[0058] d. Determine if the rockfall has stopped. If it has stopped, end the process; if it has not stopped, continue with step e.

[0059] e. Determine whether the falling rocks have turned into rolling rocks. If the falling rocks have not turned into rolling rocks, return to step a to continue the calculation; if the falling rocks have turned into rolling rocks, continue to step f.

[0060] f. Perform rolling calculations

[0061] g. Determine if the rockfall has stopped. If it has stopped, end the process; if it has not stopped, continue with step h.

[0062] h. Determine whether the falling rocks have changed to flight. If the falling rocks have not changed to flight, return to step f to continue the calculation; if the falling rocks have changed to flight, return to step a to continue the calculation.

[0063] The parameters for preventing rockfalls in step iv include the protection range, protection strength, and protection height of the retaining structure.

[0064] Determining the protection range includes the following steps:

[0065] First, obtain the three-dimensional spatial physical motion analysis model of step ii and the three-dimensional migration path of the falling rocks in step iii;

[0066] Then, determine the spatial relationship between the trajectory of the falling rocks and the railway engineering;

[0067] Finally, the protection zone of the railway is determined in order to intercept falling rocks.

[0068] Determining the protection strength includes the following steps:

[0069] First, the three-dimensional migration path equation of the falling rocks is obtained;

[0070] Then, the velocity of the falling rocks at different trajectory points is obtained;

[0071] Finally, the impact energy is obtained through the kinetic energy theorem. The impact energy is used to determine the protective strength of the barrier project, and the protective strength is greater than the impact energy.

[0072] Determining the protection height includes the following steps:

[0073] First, the three-dimensional spatial physical motion analysis model was obtained;

[0074] Then, using GIS technology, the vertical height difference between the trajectory points of the three-dimensional migration path of the falling rocks and their respective cell is calculated to obtain the bounce height of the falling rocks.

[0075] Finally, the protective height of the barrier project was determined, and the protective height is higher than the bounce height of the falling rocks.

[0076] Step v. Display of 3D simulation results of falling rocks, including 3D visualization of the rockfall migration path; color stretching display of impact energy, velocity, and bounce height values; and dynamic display of 3D motion trajectory.

[0077] Step i: Obtain remote sensing imagery, digital elevation data, and engineering information for the target area, including the following steps:

[0078] First, acquire high-resolution remote sensing image data of the target area.

[0079] High-resolution remote sensing image data includes satellite image data and aerial image data. Satellite image data and aerial image data require a resolution of less than 2m, clear image data, uniform color, and no obvious spots, streaks, or bad lines.

[0080] Then, high-precision digital elevation data of the tunnel area is obtained.

[0081] High-precision digital elevation data includes high-precision elevation data directly acquired by synthetic aperture radar and airborne laser scanners, as well as contour data from large-scale topographic maps.

[0082] Next, obtain railway engineering data for the target area.

[0083] Railway engineering data includes horizontal and vertical profile information of the line and the specific locations of railway engineering projects (roadbed, bridges, tunnels) in the target area.

[0084] Finally, obtain slope and rockfall parameters.

[0085] Slope parameters include: the tangential coefficient of restitution (R²) for different slope types (rock slope, scree slope, soil slope) and vegetation cover types (grass, shrubs, trees). t Normal recovery coefficient (R) n ), rolling friction coefficient;

[0086] The parameters of the unstable rockfall include: the three-dimensional coordinates (X, Y, Z) of the center of mass of the unstable rockfall, its dimensions (length: a, width: b, height: c), mass (m), location of joints and fissures, and uniaxial compressive strength (R). c The interaction time (Δt) between dangerous rocks and different slope types was measured using an accelerometer.

[0087] Step ii. The specific process of constructing the three-dimensional spatial physical motion analysis model is as follows:

[0088] The high-resolution remote sensing image data, high-precision digital elevation data, and railway engineering data obtained in step i are preprocessed to construct a three-dimensional spatial physical motion analysis model.

[0089] First, high-precision digital elevation data is processed using grid and triangular mesh modeling techniques to construct a digital elevation model.

[0090] Then, GIS technology is used to process the digital elevation model to obtain the dip angle (θ∈0, 90°) and dip direction of each cell. Center point coordinates P0(X) i Y i Z iConstruct plane equations for each cell based on the global Cartesian coordinate system;

[0091] Then, using the horizontal and vertical profile information of the line and the specific location of the railway engineering (roadbed, bridge, tunnel) in the target area, the three-dimensional coordinate points (X, Y, Z) of the line and railway engineering are extracted, and the three-dimensional coordinate points (X, Y, Z) of the line, railway engineering and the centroid of the dangerous rocks and falling rocks are made into three-dimensional vector data.

[0092] Then, based on high-resolution remote sensing image data, the slope type (rock slope, gravel slope, soil slope) and vegetation cover type (grass, shrubs, trees) of the target area were classified.

[0093] Next, using GIS technology, a three-type categorized dataset is defined for each cell in the digital elevation model, containing three parameters: tangential restoration coefficient (Rt), normal restoration coefficient (Rn), and rolling friction coefficient.

[0094] Then, based on slope type (rock slope, gravel slope, soil slope) and vegetation cover type (grass, shrubs, trees), different tangential coefficient of restitution (R²) values ​​are assigned to each cell of the digital elevation model's typed dataset. t ), normal recovery coefficient value (R) n ), rolling friction coefficient value;

[0095] Finally, the digital elevation model is fused and rendered with high-resolution remote sensing image data, and three-dimensional vector data is inserted to construct a three-dimensional spatial physical motion analysis model.

[0096] Another embodiment

[0097] This embodiment is illustrated with data.

[0098] A three-dimensional numerical simulation method for railway rockfall based on remote sensing technology includes the following steps:

[0099] i. Acquire remote sensing images, digital elevation data, and engineering data for the target area.

[0100] ii. Construct a three-dimensional spatial physical motion analysis model

[0101] iii. Calculate the three-dimensional migration path of falling rocks.

[0102] iv. Determine parameters for preventing rockfalls.

[0103] v. Display of 3D simulation results of dangerous rockfall.

[0104] After obtaining high-resolution remote sensing image data, high-precision digital elevation data, and railway engineering data for the target area in step i, it is also necessary to obtain slope and rockfall parameters.

[0105] The target area includes the area where dangerous rocks and rocks are developed and the area affected by dangerous rocks and rocks.

[0106] Step ii involves preprocessing high-resolution remote sensing image data, high-precision digital elevation data, and railway engineering data to construct a three-dimensional spatial physical motion analysis model.

[0107] Step iii calculates the three-dimensional migration path of the falling rocks, including the following processes:

[0108] a. Start simulation

[0109] b. Perform flight / bounce calculations

[0110] c. Determine whether the dangerous rockfall has been damaged. If the dangerous rockfall has been damaged, return to step a to continue the calculation; if the dangerous rockfall has not been damaged, continue to step d.

[0111] d. Determine if the rockfall has stopped. If it has stopped, end the process; if it has not stopped, continue with step e.

[0112] e. Determine whether the falling rocks have turned into rolling rocks. If the falling rocks have not turned into rolling rocks, return to step a to continue the calculation; if the falling rocks have turned into rolling rocks, continue to step f.

[0113] f. Perform rolling calculations

[0114] g. Determine if the rockfall has stopped. If it has stopped, end the process; if it has not stopped, continue with step h.

[0115] h. Determine whether the falling rocks have changed to flight. If the falling rocks have not changed to flight, return to step f to continue the calculation; if the falling rocks have changed to flight, return to step a to continue the calculation.

[0116] Step iii: Calculate the three-dimensional migration path of the falling rocks. Based on the construction of a three-dimensional spatial physical motion analysis model, the momentum theorem is used to determine the damage state of the falling rocks. Based on the particle collision rebound model and the parabola principle, the flight / bouncing and rolling of the falling rocks are calculated using Newton's second law and kinematic formulas to obtain the three-dimensional migration path of the falling rocks.

[0117] The parameters for preventing rockfalls in step iv include the protection range, protection strength, and protection height of the retaining structure.

[0118] Determining the protection range includes the following steps:

[0119] First, obtain the three-dimensional spatial physical motion analysis model of step ii and the three-dimensional migration path of the falling rocks in step iii;

[0120] Then, determine the spatial relationship between the trajectory of the falling rocks and the railway engineering;

[0121] Finally, the protection zone of the railway is determined in order to intercept falling rocks.

[0122] Determining the protection strength includes the following steps:

[0123] First, the three-dimensional migration path equation of the falling rocks is obtained;

[0124] Then, the velocity of the falling rocks at different trajectory points is obtained;

[0125] Finally, the impact energy is obtained through the kinetic energy theorem. The impact energy is used to determine the protective strength of the barrier project, and the protective strength is greater than the impact energy.

[0126] Determining the protection height includes the following steps:

[0127] First, the three-dimensional spatial physical motion analysis model was obtained;

[0128] Then, using GIS technology, the vertical height difference between the trajectory points of the three-dimensional migration path of the falling rocks and their respective cell is calculated to obtain the bounce height of the falling rocks.

[0129] Finally, the protective height of the barrier project was determined, and the protective height is higher than the bounce height of the falling rocks.

[0130] Compared to the previous embodiment, this embodiment describes the calculation of the three-dimensional migration path of falling rocks. Based on the construction of a three-dimensional spatial physical motion analysis model, the momentum theorem is used to determine the failure state of the falling rocks. Based on the particle collision and rebound model and the parabolic principle, Newton's second law and kinematic formulas are used to calculate the flight / bouncing and rolling of the falling rocks, thus obtaining the three-dimensional migration path of the falling rocks.

[0131] Step b assumes the initial motion state of the falling rocks is flight. Set the initial horizontal velocity, initial vertical velocity, and starting direction of motion of the falling rocks. The starting direction of motion is the tilt direction of the cell in which the falling rocks are located, and perform flight / bounce calculations.

[0132] Step c: After the dangerous rockfall collides with the slope, the damage status is determined. If damage occurs, all n (n≥2) dangerous rockfalls after damage are repeated in step a; otherwise, proceed to step c.

[0133] Step f involves calculating the rolling motion of the falling rocks. If the speed of movement changes, the motion state is determined. If the state stops, the calculation ends; otherwise, the state changes to flight.

[0134] The specific process of performing flight / bounce calculations in step b is as follows:

[0135] First, based on the three-dimensional coordinates (X, Y, Z) of the falling rocks, their horizontal and vertical velocities, and their direction of motion, the three-dimensional flight path equation of the falling rocks in the global Cartesian coordinate system is constructed using the principle of parabolic motion, thus obtaining the flight trajectory line.

[0136] Then, the impact point is obtained by calculating the intersection of the flight trajectory line and the cell surface. The inclination angle, dip, and center point coordinates of the cell where the impact point is located are obtained, and a local coordinate system of the cell slope is established.

[0137] Then, the three-dimensional flight path equation of the falling rocks in the global Cartesian coordinate system is converted into the path equation in the local coordinate system of the slope through the coordinate transformation matrix.

[0138] Next, using the point mass collision rebound model, the tangential recovery coefficient (R0) is determined based on the typed dataset corresponding to the cell containing the falling rock. t ) and normal recovery coefficient value (R n Calculate the velocity vector equation of the slope in the local coordinate system and convert it into the velocity vector equation in the global Cartesian coordinate system.

[0139] Then, based on the bouncing velocity vector equation in the global Cartesian coordinate system, a three-dimensional flight path equation for falling rocks in the global Cartesian coordinate system is constructed to obtain a new flight trajectory line.

[0140] The specific process of performing the rolling calculation in step f is as follows:

[0141] First, determine the tendency of cell A where the rockfall is located. Inclination angle θ A .

[0142] Then, determine the range of preference for cell A. Inner grid B (A21, A23, A31, A32, A33) represents the cells in the scrolling direction, such as... Figure 3 As shown.

[0143] Then, if Then determine maxθ B The current cell is the next cell after scrolling. Then determine minθ B The current cell is the next cell in the scroll.

[0144] Next, by default, the falling rocks will scroll along the center of the cell. By repeating the above steps, you can get the rolling path of the falling rocks.

[0145] Finally, based on the inclination angle in the corresponding cell on the theoretical rolling path and the rolling friction coefficient in the typified dataset, the equation of the rockfall rolling path in the global Cartesian coordinate system is calculated using Newton's second law and kinematic formulas.

[0146] In this embodiment, the motion state of the falling rocks consists of three states: flying, rolling, and stopping, and these three states can be switched between each other.

[0147] In this embodiment, the calculation of the three-dimensional migration path of the falling rocks includes the determination of the motion state, including: rolling state → flying state determination, flying state → rolling state determination, and flying / rolling state → stopping determination.

[0148] Among them, rolling state → flying state

[0149] Based on the direction of the falling rock movement, the falling rock enters the next unit from the previous unit along the incident direction. The angle β between the normal vectors (normal 1 and normal 2) of the two units is obtained. If the falling rock movement speed is greater than 5m / s when entering the next unit and β>45°, the movement state changes from rolling to flying; otherwise, it remains in the rolling state.

[0150] Flight state → Rolling state

[0151] If the speed of the falling rock is less than or equal to 0.5 m / s, the motion state changes from flying to rolling; otherwise, it remains in flying state.

[0152] Flight / Rolling State → Stop

[0153] If the speed of the falling rock is less than or equal to 0.01 m / s, the motion state changes from flying / rolling to stopping.

[0154] In this embodiment, the calculation of the three-dimensional migration path of falling rocks includes the determination of the damage state, and the specific process is as follows:

[0155] First, based on the three-dimensional flight path equation of the falling rock, calculate the velocity at the impact point.

[0156] v 撞 .

[0157] Then, calculate the comprehensive stress area based on the size of the falling rocks.

[0158] Then, based on the uniaxial compressive strength (R c ), calculate the critical value P for brittle failure due to falling rocks. 破 =R c ×A.

[0159] Next, the interaction time (Δt) between the unstable rockfall and different slope types is obtained. Based on the momentum theorem, when When a rockfall occurs, for rockfalls with joints and fissures, brittle fracture occurs along the joints and fissures, resulting in n new rockfalls (n≥2). The masses of the new rockfalls, m1, m2…m, are determined based on the location of the joints and fissures.n ,like Figure 5 As shown; for unjointed rockfalls, brittle fracture occurs along the fracture surface in the middle of the rockfall, yielding two new rockfalls, each with a mass of m / 2, as shown. Figure 6 As shown;

[0160] Finally, after the rockfall is destroyed, new rocks will move towards the air along the normal vector of the central fracture surface or the normal vector of the joints and fissures.

[0161] Step v. Display of 3D simulation results of falling rocks, including 3D visualization of the rockfall migration path; color stretching display of impact energy, velocity, and bounce height values; and dynamic display of 3D motion trajectory.

[0162] Among them, the 3D visualization of the migration path of dangerous rocks is based on the GIS platform. The 3D coordinate points (X, Y, Z) of the 3D migration path of dangerous rocks are extracted, and 3D vector data in shp format is made. Then, step S2 is inserted to construct a 3D spatial physical motion analysis model to realize the 3D visualization of the migration path of dangerous rocks.

[0163] Using GIS visualization technology, the impact energy, velocity, and bounce height values ​​of the falling rocks obtained in step iv are resampled and converted into pixel data, which correspond one-to-one with the three-dimensional coordinate points (X, Y, Z) of the falling rocks migration path. The data is then inserted into the three-dimensional spatial physical motion analysis model constructed in step ii and displayed with color stretching. Preferably, red is defined as high value, green as low value, and intermediate colors are interpolated.

[0164] Select a three-dimensional migration path of the falling rocks and assign a velocity value; create a three-dimensional solid model based on the shape of the falling rocks and place it at the origin of the path, insert it into step ii to construct a three-dimensional spatial physical motion analysis model, and use the GIS animation display module to dynamically display the three-dimensional motion trajectory of the falling rocks according to the velocity change and time sequence.

[0165] The present invention provides a three-dimensional numerical simulation calculation method for railway rockfall based on remote sensing technology. This method can accurately calculate the three-dimensional migration path of rockfall using remote sensing and GIS technology, obtain rockfall prevention parameters, and determine the protection range, strength and height of barrier projects. It can also realize the display of three-dimensional simulation results of rockfall. The method is not only highly accurate and simple, but also has low material cost and strong engineering applicability.

Claims

1. A railway dangerous rockfall three-dimensional numerical simulation calculation method based on remote sensing technology, characterized in that: The method comprises the following steps: (i) obtaining remote sensing image and digital elevation data of target area and engineering data (ii) constructing three-dimensional space physical motion analysis model (iii) calculating three-dimensional migration path of dangerous rockfall (iv) determining dangerous rockfall prevention parameters (v) displaying three-dimensional simulation results of dangerous rockfall The calculation of the three-dimensional migration path of the dangerous rockfall includes the determination of the damage state, and the specific process is as follows: Firstly, according to the three-dimensional flight path equation of the dangerous rock falling, the speed value v at the impact point is calculated 撞 ; Then, according to the size of the dangerous rockfall, the comprehensive stress area is calculated ; Then, according to the uniaxial compressive strength (R c ), the critical value of brittle failure of dangerous rockfall is calculated ; Then, the interaction time (Δt) between rockfall and different slope types is obtained. Based on the momentum theorem, when rockfall occurs, for the rockfall with joint fissure, brittle failure occurs along the joint fissure, n new rockfalls (n≥2) are obtained, and the masses m1, m2…mn of the new rockfalls are obtained according to the position of the joint fissure. n For the rockfall without joint fissure, brittle failure occurs along the middle fracture surface of the rockfall, and 2 new rockfalls are obtained. Finally, after the rockfall is damaged, the new rockfall will move along the normal vector of the central fracture surface or the normal vector of the joint crack to the open space.

2. The remote sensing technology-based railway dangerous rockfall three-dimensional numerical simulation calculation method according to claim 1, characterized in that: After obtaining the high-resolution remote sensing image data and high-precision digital elevation data of the target area and the railway engineering data in step (i), the slope and dangerous rockfall parameters are also obtained.

3. The remote sensing technology-based railway dangerous rockfall three-dimensional numerical simulation calculation method according to claim 2, characterized in that: The target area includes a dangerous rockfall development area and a dangerous rockfall influence area.

4. The remote sensing technology-based railway dangerous rockfall three-dimensional numerical simulation calculation method according to claim 2, characterized in that: In step (ii), the high-resolution remote sensing image data and high-precision digital elevation data and railway engineering data are preprocessed to construct a three-dimensional space physical motion analysis model.

5. The remote sensing technology-based railway dangerous rockfall three-dimensional numerical simulation calculation method according to claim 1, characterized in that: In step (iii), the three-dimensional migration path of the dangerous rockfall is calculated, including the following processes: (a) start simulation (b) perform flight / bounce calculation (c) determine whether the dangerous rockfall is damaged, if the dangerous rockfall is damaged, return to step (a) and continue calculation; if the dangerous rockfall is not damaged, continue to step (d); (d) determine whether the dangerous rockfall stops, if the dangerous rockfall stops, end; if the dangerous rockfall does not stop, continue to step (e); (e) determine whether the dangerous rockfall turns into rolling, if the dangerous rockfall does not turn into rolling, return to step (a) and continue calculation; if the dangerous rockfall turns into rolling, continue to step (f); (f) perform rolling calculation (g) determine whether the dangerous rockfall stops, if the dangerous rockfall stops, end; if the dangerous rockfall does not stop, continue to step (h); (h) determine whether the dangerous rockfall turns into flight, if the dangerous rockfall does not turn into flight, return to step (f) and continue calculation; if the dangerous rockfall turns into flight, return to step (a) and continue calculation.

6. The remote sensing technology-based railway dangerous rockfall three-dimensional numerical simulation calculation method according to claim 1, characterized in that: The dangerous rockfall prevention parameters in step (iv) include the protection range, protection strength and protection height of the blocking project.

7. The remote sensing technology-based railway dangerous rockfall three-dimensional numerical simulation calculation method according to claim 6, characterized in that: The determination of the protection range includes the following steps: First, obtain the three-dimensional space physical motion analysis model in step (ii) and the three-dimensional migration path of the dangerous rockfall in step (iii); Then, determine the spatial relationship between the rockfall trajectory and the railway engineering; Finally, determine the protection range of the railway to intercept the dangerous rockfall.

8. The remote sensing technology-based railway dangerous rockfall three-dimensional numerical simulation calculation method according to claim 6, characterized in that: The determination of the protection strength includes the following steps: First, obtain the three-dimensional migration path equation of the dangerous rockfall; Then, obtain the motion speed of the dangerous rockfall at different trajectory points; Finally, obtain the impact energy by the kinetic energy theorem, and the impact energy is used to determine the protection strength of the blocking project, and the protection strength is greater than the impact energy.

9. The remote sensing technology-based railway dangerous rockfall three-dimensional numerical simulation calculation method according to claim 6, characterized in that: The determination of the protection height includes the following steps: First, obtain the three-dimensional space physical motion analysis model; Then, calculate the vertical height difference between the trajectory point of the three-dimensional migration path of the dangerous rockfall and the unit cell where it is located using GIS technology to obtain the bounce height of the dangerous rockfall, Finally, determine the protection height of the blocking project, and the protection height is higher than the bounce height of the dangerous rockfall. 10.The remote sensing technology-based railway dangerous rockfall three-dimensional numerical simulation calculation method according to claim 1, characterized in that: Step (v) the three-dimensional simulation results of rockfall, including the three-dimensional visualization of rockfall migration path; color stretching display of impact energy, speed, and bounce height value; dynamic display of three-dimensional motion trajectory.

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