Discrete element simulation method for protection against rolling rock disasters on slopes

Abstract

The present invention relates to the field of slope rockfall disaster simulation, and particularly to a discrete element simulation method for slope rockfall disaster protection, which greatly improves the effective protection ability against rockfall disasters. The discrete element simulation method for slope rockfall disaster protection of the present invention includes: performing discrete element simulation on different types of rockfalls; performing discrete element simulation on slopes where different rockfall disasters occur; performing discrete element simulation on different preset passive protection nets; and analyzing the bouncing process and speed change process of rockfalls. The present invention is applicable to slope rockfall disaster protection.

Description

Technical Field

[0001] The present invention relates to the field of slope rockfall disaster simulation, and specifically relates to a discrete element simulation method for slope rockfall disaster prevention and protection. Background Art

[0002] With the rapid development of water conservancy, transportation, municipal administration, and tourism development and construction in the southwestern region of China, engineering construction on high mountains and deep valleys is common. These engineering constructions are often carried out under the working conditions of high and steep slopes, such as the mountain slopes formed by building reservoir bank roads. Under the action of loads and external influences such as self-weight, weathering, water pressure, and operation disturbance, these slopes are extremely prone to rockfall disasters. Rockfall disasters are characterized by universality, suddenness, and randomness. Rockfall disasters can damage roads and important pipelines, posing safety hazards to passing vehicles, personnel, and materials.

[0003] The existing research on rockfall disasters, such as a rockfall disaster risk assessment method, device, system, and storage medium disclosed in CN109933921B, includes: obtaining the rockfall disaster-causing factors within the range of a first preset area; inputting the rockfall disaster-causing factors into a pre-established statistical model to obtain the rockfall source points and the corresponding probability values of the rockfall source points; using a physical model to simulate the rockfall path starting from the rockfall source points; calculating the length of the rockfall path within a second preset area; and calculating the risk index of rockfall disasters occurring within the second preset area according to the search radius, the rockfall path, the length of the rockfall path, the number of rockfall paths, and the probability values corresponding to the rockfall source points in the rockfall path. By this means, the purpose of accurately measuring the rockfall risk is achieved. The higher the risk index, the greater the risk of rockfall disasters.

[0004] However, the comparative document CN109933921B only conducts a detailed research and analysis on the probabilities of the path, length, radius, etc. of rockfall occurrence, lacking a specific analysis of the slopes where different rockfall disasters occur, different passive protection nets, and the bouncing process and speed change process of rockfalls. As a result, the risk assessment data of rockfall disasters is not accurate, and effective protection against rockfall disasters cannot be carried out. Summary of the Invention

[0005] The purpose of the present invention is to provide a discrete element simulation method for slope rockfall disaster prevention and protection, which greatly improves the effective protection ability against rockfall disasters.

[0006] The present invention adopts the following technical solutions to achieve the above purpose. The discrete element simulation method for slope rockfall disaster prevention and protection includes:

[0007] Step 1: Conduct discrete element simulation on different types of rockfalls;

[0008] Step 2: Conduct discrete element simulation on the slopes where different rockfall disasters occur;

[0009] Step 3: Conduct discrete element simulations on different preset passive protection nets;

[0010] Step 4: Analyze the bouncing process and speed change process of the rolling stones.

[0011] Furthermore, in Step 1, the discrete element simulation of different types of rolling stones specifically includes:

[0012] Step 101: Import the STL file of the rolling stone model, and determine the intervals in the x, y, and z directions according to the position of the rolling stone model, so that the framed hexahedral space can completely contain the rolling stone;

[0013] Step 102: Randomly fill a hexahedral space determined by the selected rolling stone position coordinates with spherical particles of a set radius;

[0014] Step 103: Use the principle of Boolean operation to delete the spherical particles within the framed hexahedral space and outside the surface of the rolling stone model;

[0015] Step 104: Apply a bonding model between the particles to generate a rolling stone with a specific shape formed by bonding spherical particles, and set the cohesion, tensile strength, normal stiffness, and shear stiffness between the particles;

[0016] Step 105: Complete the discrete element simulation of different types of rolling stones.

[0017] Furthermore, in Step 2, the discrete element simulation of the slopes where different rolling stone disasters occur specifically includes:

[0018] Step 201: Control the mesh size through the Number Slider to achieve the simulation of different smoothness degrees of the slope;

[0019] Step 202: Import the STL file of the slope model to generate a surface-filled slope mesh;

[0020] Step 203: Set the normal stiffness and shear stiffness of the slope surface;

[0021] Step 204: Complete the discrete element simulation of the slopes where different rolling stone disasters occur.

[0022] Furthermore, in Step 3, the discrete element simulation of different preset passive protection nets specifically includes:

[0023] Step 301: Set the coordinate intervals in the x, y, and z directions to determine the generation position, height, and length of the protection net;

[0024] Step 302: Set the radius of the protective net particles, construct a particle model with adjacent arrangement using a loop control command, and then bond the particles using a parallel bond model to construct a discrete element model of the rectangular passive protection net;

[0025] Step 303: Set the cohesion, internal friction angle, tensile strength, friction coefficient, and moment contribution factor;

[0026] Step 304: Complete the discrete element simulation of different preset passive protection nets.

[0027] Furthermore, in Step 4, the analysis of the bouncing process of the rolling stone specifically includes:

[0028] Taking the elapsed time t after the release of the rolling stone as the abscissa and the slope elevation y as the ordinate, calculate the slope profile. The calculation process is as follows: First, determine the x i and y i coordinates of the rolling stone at a certain moment t i , then determine the elevation of the slope surface at these x i and y i coordinates, calculate the slope elevation under the rolling trajectory of the rolling stone at any moment, and complete the calculation of the slope profile;

[0029] Use the record coordinate command to record the z - coordinate of the rolling stone and its fragments, calculate the elevation h i of the rolling stone and its fragments at any moment t i . Taking the elapsed time t after the release of the rolling stone as the abscissa and the elevation h of the rolling stone and its fragments as the ordinate, obtain the curve relationship between the elapsed time t after the release of the rolling stone and the elevation h of the rolling stone and its fragments, and realize the calculation of the bouncing process;

[0030] Combining the bouncing process and the slope profile, draw the curve relationship between the elapsed time t after the release of the rolling stone, the elevation h of the rolling stone and its fragments, and the slope elevation y. Through this curve relationship, obtain the bouncing heights of the rolling stone and its main fragments at different moments.

[0031] Furthermore, in Step 4, the analysis of the speed change process of the rolling stone specifically includes:

[0032] Use the command to detect speed to monitor the velocities v i in each direction of the main body of the rolling stone at time t 1i , v 2i and v 3i , and calculate the velocity v i of the broken main body of the rolling stone at any moment t i ;

[0033] Taking the elapsed time t after the release of the rolling stone as the abscissa, and v1, v2, and v3 as the ordinates respectively, plot the curve of the elapsed time t and the velocity components; v1 is the velocity of the rolling stone in the x direction, v2 is the velocity of the rolling stone in the y direction, v3 is the velocity of the rolling stone in the z direction, and v is the instantaneous velocity of the main body of the rolling stone.

[0034] Perform vector synthesis to calculate the component velocities at each moment. The calculation formula is Obtain the curve relationship between the elapsed time after the release of the rolling stone and the instantaneous velocity of the main body of the rolling stone.

[0035] The beneficial effects of the present invention are as follows:

[0036] Through the discrete element simulation of different types of rolling stones, the discrete element simulation of slopes where different rolling stone disasters occur, the discrete element simulation of different preset passive protection nets, and the analysis of the bouncing process and velocity change process of rolling stones, the present invention determines the detailed parameters of rolling stones, slopes, and protection nets, simulates the bouncing process and velocity change process of rolling stones under actual working conditions, as well as the protection effect, can provide effective data support for the protection of rolling stone disasters, and greatly improves the effective protection ability against rolling stone disasters. Description of the Drawings

[0037] Figure 1 It is a flow chart of the discrete element simulation for the protection of slope rolling stone disasters provided by an embodiment of the present invention. Detailed Embodiments

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] The present invention provides a discrete element simulation method for the protection of slope rolling stone disasters, as Figure 1 shown, including:

[0040] Step 1: Perform discrete element simulation on different types of rolling stones;

[0041] Step 2: Perform discrete element simulation on slopes where different rolling stone disasters occur;

[0042] Step 3: Perform discrete element simulation on different preset passive protection nets;

[0043] Step 4: Analyze the bouncing process and velocity change process of rolling stones.

[0044] In one embodiment of the present invention, in step 1, the discrete element simulation of different types of rolling stones specifically includes:

[0045] Step 101: Import the STL file of the rolling stone model, and determine the intervals in the x, y, and z directions according to the position of the rolling stone model, so that the framed hexahedron space can completely contain the rolling stone;

[0046] Step 102: Randomly fill a hexahedron space determined by the selected rolling stone position coordinates with spherical particles of a set radius;

[0047] Step 103: Use the principle of Boolean operation to delete the spherical particles inside the framed hexahedron space and outside the surface of the rolling stone model;

[0048] Step 104: Apply a bonding model between the particles to generate a rolling stone with a specific shape formed by bonding spherical particles, and set the cohesion, tensile strength, normal stiffness, and tangential stiffness between the particles, so that the rolling stone model has certain mechanical properties;

[0049] Step 105: Complete the discrete element simulation of different types of rolling stones.

[0050] In one embodiment of the present invention, in step 2, the discrete element simulation of the slopes where different rolling stone disasters occur specifically includes:

[0051] Step 201: Control the mesh size through the Number Slider to achieve the simulation of different smoothness degrees of the slope. The Number Slider is a component for controlling the mesh size;

[0052] Step 202: Import the STL file of the slope model to generate a surface-filled slope mesh;

[0053] Step 203: Set the normal stiffness and tangential stiffness of the slope surface to make the slope model have mechanical properties;

[0054] Step 204: Complete the discrete element simulation of the slopes where different rolling stone disasters occur.

[0055] In one embodiment of the present invention, in step 3, the discrete element simulation of different preset passive protection nets specifically includes:

[0056] Step 301: Set the coordinate intervals in the x, y, and z directions to determine the generation position, height, and length of the protection net;

[0057] Step 302: Set the radius of the protection net particles, use the loop control command to construct an adjacent arrangement of particle models, and then bond the particles using the parallel bonding model to achieve the construction of a rectangular passive protection net discrete element model;

[0058] Step 303: Set the cohesion, internal friction angle, tensile strength, friction coefficient, and moment contribution factor so that the protective net has specific mechanical properties;

[0059] Step 304: Complete the discrete element simulations of different preset passive protective nets.

[0060] After completing the discrete element simulations of different types of rolling stones, the discrete element simulations of slopes where different rolling stone disasters occur, and the discrete element simulations of different preset passive protective nets, analyze the bouncing process and speed change process of the rolling stones.

[0061] In an embodiment of the present invention, in step 4, the analysis of the bouncing process of the rolling stones specifically includes:

[0062] Slope shape calculation: Taking the elapsed time t after the release of the rolling stone as the abscissa and the slope elevation y as the ordinate, calculate the slope shape contour. The calculation process is as follows: First, determine the x i and y i coordinates of the rolling stone at a certain moment t, and then determine the elevation of the slope surface at these x i and y i coordinates. Calculate the elevation of the slope under the rolling stone's rolling trajectory at any moment to complete the slope shape calculation; i Bouncing process calculation: Use the record coordinate command to record the z - direction coordinates of the rolling stone and its fragments, and calculate the elevation h

[0063] of the rolling stone and its fragments at any moment t i的 . Taking the elapsed time t after the release of the rolling stone as the abscissa and the elevation h of the rolling stone and its fragments as the ordinate, obtain the curve relationship between the elapsed time t after the release of the rolling stone and the elevation h of the rolling stone and its fragments to achieve the bouncing process calculation; i Combining the bouncing process and the slope shape, draw the curve relationship between the elapsed time t after the release of the rolling stone, the elevation h of the rolling stone and its fragments, and the slope elevation y. Through this curve relationship, obtain the bouncing heights of the rolling stone and its main fragments at different moments.

[0064] The analysis of the speed change process of the rolling stones specifically includes:

[0065] Use the command to detect speed to monitor the velocities v

[0066] in each direction of the main body of the rolling stone at time t i , v 1i , v 2i and v 3i , and calculate the speed v i of the broken main body of the rolling stone at any moment t i ;

[0067] Taking the elapsed time t after the release of the rolling stone as the abscissa, and v1, v2, and v3 as the ordinates respectively, plot the curve of the elapsed time t and the velocity components; v1 is the velocity of the rolling stone in the x direction, v2 is the velocity of the rolling stone in the y direction, v3 is the velocity of the rolling stone in the z direction, and v is the instantaneous velocity of the main body of the rolling stone;

[0068] Perform vector synthesis to calculate the component velocities at each moment. The calculation formula is Obtain the curve relationship between the elapsed time t after the release of the rolling stone and the instantaneous velocity of the main body of the rolling stone.

[0069] In summary, the present invention can provide effective data support for the prevention of rolling stone disasters and greatly improve the effective prevention ability of rolling stone disasters.

Claims

1. Discrete element simulation method for protecting slope rolling stone disasters, characterized in that, Including: Step 1: Conduct discrete element simulations on different types of rolling stones; Step 2: Conduct discrete element simulations on slopes where different rolling stone disasters occur; Step 3: Conduct discrete element simulations on different preset passive protection nets; Step 4: Analyze the bouncing process and speed change process of rolling stones; In Step 4, the analysis of the bouncing process of rolling stones specifically includes: Taking the elapsed time t after the rolling stone is released as the abscissa and the slope elevation y as the ordinate, calculate the slope profile. The calculation process is as follows: First, determine the x i and y i coordinates of the rolling stone at a certain moment t i , then determine the elevation of the slope surface at this x i and y i coordinates, calculate the elevation of the slope under the rolling trajectory of the rolling stone at any moment, and complete the calculation of the slope profile; Use the record coordinate command to record the z - coordinate of the rolling stone and its fragments, and calculate the elevation h of the rolling stone and its fragments at any time t i The elevation h of the rolling stone and its fragments i , with the elapsed time t after the release of the rolling stone as the abscissa and the elevation h of the rolling stone and its fragments as the ordinate, obtain the curve relationship between the elapsed time t after the release of the rolling stone and the elevation h of the rolling stone and its fragments, and realize the calculation of the bouncing process; Combining the bouncing process and the slope morphology, draw the curve relationship between the elapsed time t after the release of the rolling stone, the elevation h of the rolling stone and its fragments, and the elevation y of the slope. Through this curve relationship, obtain the bouncing heights of the rolling stone and its main fragments at different times; In Step 4, the analysis of the speed change process of rolling stones specifically includes: Use the command of detection speed to monitor the velocities v i in each direction of the rolling stone body at time t 1i , v 2i and v 3i , and calculate the velocity v i of the rolling stone crushing body at any time t i ; Taking the elapsed time t after the release of the rolling stone as the abscissa, and taking v1, v2, and v3 as the ordinates respectively, draw the curve of the elapsed time t and the velocity components; v1 is the velocity of the rolling stone in the x direction, v2 is the velocity of the rolling stone in the y direction, v3 is the velocity of the rolling stone in the z direction, and v is the instantaneous velocity of the main body of the rolling stone; The vector synthesis calculates the component velocities at each moment, and the calculation formula is The curve relationship between the elapsed time after the release of the rolling stone and the instantaneous velocity of the rolling stone body is obtained.

2. The discrete element simulation method for slope rockfall disaster prevention according to claim 1, wherein In Step 1, the discrete element simulation of different types of rolling stones specifically includes: Step 101: Import the STL file of the rolling stone model, and determine the intervals in the x, y, and z directions according to the position of the rolling stone model, so that the framed hexahedral space can completely contain the rolling stone; Step 102: Randomly fill a hexahedral space determined by the selected rolling stone position coordinates with spherical particles of a set radius; Step 103: Using the principle of Boolean operation, delete the spherical particles inside the framed hexahedral space and outside the surface of the rolling stone model; Step 104: Apply a bonding model between the particles to generate a rolling stone with a specific morphology formed by bonding spherical particles, and set the cohesion, tensile strength, normal stiffness, and tangential stiffness between the particles; Step 105: Complete the discrete element simulation of different types of rolling stones.

3. The discrete element simulation method for slope rockfall disaster prevention according to claim 1, characterized in that In Step 2, the discrete element simulation of slopes where different rolling stone disasters occur specifically includes: Step 201: Control the grid size through the Number Slider to achieve the simulation of different smoothness degrees of the slope; Step 202: Import the STL file of the slope model to generate a surface-filled slope grid; Step 203: Set the normal stiffness and tangential stiffness of the slope surface; Step 204: Complete the discrete element simulation of slopes where different rolling stone disasters occur.

4. The discrete element simulation method for slope rockfall disaster prevention according to claim 1, characterized in that In Step 3, the discrete element simulation of different preset passive protection nets specifically includes: Step 301: Set the coordinate intervals in the x, y, and z directions to determine the generation position, height, and length of the protection net; Step 302: Set the radius of the particles of the protection net, use the loop control command to construct an adjacent arrangement of particle models, and then bond the particles using the parallel bonding model to realize the construction of the discrete element model of the rectangular passive protection net; Step 303: Set the cohesion, internal friction angle, tensile strength, friction coefficient, and moment contribution factor; Step 304: Complete the discrete element simulation of different preset passive protection nets.

Images