A reasonable blasting lump size determination method based on numerical calculation

Abstract

The application discloses a reasonable blasting block size determination method based on numerical calculation and relates to the technical field of open-pit mine blasting engineering. After overall acquisition of existing blasting design parameters and basic rock mechanics parameters, a step model of a blasting area is constructed by using Hypermesh three-dimensional modeling software, and necessary pretreatment operations such as mesh division are performed on the constructed model. Simulation calculation is performed on the output K file by using LS-DYNA finite element numerical simulation software, and detailed simulation results are viewed by means of LS-Prepost software. Monitoring points are set at key positions where large rocks are prone to be produced in the blasting process, and whether the rock is damaged is judged according to a Von Mises stress failure criterion. The method effectively solves the problems of low precision, high cost and low efficiency in the existing blasting block size determination method, significantly improves the accuracy and efficiency of the blasting block size determination, and provides a solid scientific basis for blasting design work.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of open-pit mine blasting engineering, and particularly relates to a reasonable blasting fragmentation size determination method based on numerical calculation. BACKGROUND

[0002] In open-pit mining operations, blasting is a commonly used construction method. Blasting fragmentation size is one of the important indicators to measure the blasting effect, which directly affects the efficiency and cost of subsequent loading, transportation, crushing and other processes. Too large or too small fragmentation size will bring a series of problems, such as high large block rate increasing the workload and cost of secondary crushing, and too small fragmentation size increasing dust pollution and blasting cost. Reasonable blasting fragmentation size can improve construction efficiency and reduce engineering cost.

[0003] At present, the methods for determining blasting fragmentation size mainly include empirical formula method, field test method and numerical simulation method. The empirical formula method is based on a large amount of engineering experience, and the calculation is simple, but the precision is low and is greatly affected by geological conditions and blasting parameters. The field test method obtains blasting fragmentation size data through blasting tests with different parameters in the field, and the precision is high, but a large amount of manpower, material resources and time are consumed, and there is a certain safety risk in the test process. The numerical simulation method can obtain the propagation law of blasting stress in rock and the stress change curve of rock element in the blasting process in a short time by establishing a numerical model to simulate the blasting process. It not only saves a lot of manpower, material resources and time, but also greatly reduces the cost, and the simulation result has high precision. At the same time, it can also simulate the blasting effect under different geological conditions and blasting parameters, and has strong adaptability and wide application range. Through blasting numerical simulation, the blasting mechanism can be deeply analyzed, the blasting design parameters can be optimized, the blasting quality can be improved, and the blasting construction safety can be ensured. SUMMARY

[0004] In order to solve the problems in the prior art, the present application provides a reasonable blasting fragmentation size determination method based on numerical calculation, which can improve the accuracy and efficiency of blasting fragmentation size determination and provide a scientific basis for blasting design.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a reasonable blasting fragmentation size determination method based on numerical calculation, characterized by comprising the following steps:

[0006] Step 1: Collect the existing blasting design parameters of the blasting area and rock samples, and obtain the basic mechanical parameters of the rock through laboratory mechanical testing;

[0007] Step 2: According to the existing blasting design parameters, establish a bench model of the blasting area, and perform preprocessing, set the model material parameters, multi-substance material relationship, non-reflective boundary conditions, calculation result output interval, calculation time length, and output K file;

[0008] Step 3: numerical simulation of the existing blasting scheme using LS-DYNA numerical simulation software, and analysis of the simulation results based on the Von Mises stress failure criterion;

[0009] Step 4: blasting parameter optimization based on orthogonal test, blasting process numerical simulation, and determination of the optimal blasting design scheme using range analysis method;

[0010] Step 5: verification of the optimal blasting design scheme based on numerical simulation and evaluation of the blasting effect improvement.

[0011] Preferably, the existing blasting design parameters in step 1 include step height, base resistance line, hole arrangement method, hole diameter, hole spacing, row spacing, super-deep length, filling length, explosive unit consumption, charging length, initiation method, initiation time difference, and explosive type, and the basic mechanical parameters of the rock include rock density, elastic modulus, Poisson's ratio, uniaxial compressive strength, and tensile strength.

[0012] Preferably, step 2 includes:

[0013] Step 2.1: according to the existing blasting design parameters, a step model of the blasting area is established using Hypermesh three-dimensional modeling software, and the grid is divided, for parts with larger blasting influence area, coarser grid is used, and for key areas near the blasting hole, finer grid is used to improve calculation accuracy;

[0014] Step 2.2: the divided grid elements are respectively assigned with corresponding material constitutive model and material parameter attributes, *MAT_PLASTIC_KINEMATIC is selected as the constitutive model of rock material, *MAT_HIGH_EXPLOSIVE_BURN is selected as the constitutive model of explosive material, and *EOS_JWL is used to define the state equation of explosive, which can well describe the relationship between pressure, density and specific internal energy during the explosion process of explosive, at the same time, no reflection boundary conditions are set for the other side surfaces of the model step except the top surface and slope surface, to simulate that the explosion stress generated in the blasting area can be transmitted outward infinitely in the surrounding rock which contacts it, and the multi-material material relationship, fluid-structure coupling relationship, and the solution time and output calculation result time interval of the whole simulation process are set, and finally the K file is output.

[0015] Preferably, step 3 includes:

[0016] Step 3.1: simulate and calculate the K file through LS-DYNA finite element numerical simulation software, and use LS-Prepost software to view the numerical simulation results;

[0017] Step 3.2: The monitoring points are set at the positions where large blocks are likely to be produced in bench blasting, and the change of the zone energy during the blasting process is determined by observing the propagation of the blasting stress in the rock and the stress change curve of the monitoring points during the blasting process. The Von Mises stress failure criterion is used, and the peak value of the effective stress received by the monitoring points during the explosion process is compared with the tensile strength of the rock. If it is greater than the tensile strength of the rock, it proves that the rock is damaged during the explosion process, otherwise, it is not damaged.

[0018] Preferably, the step 4 comprises:

[0019] Step 4.1: According to the existing blasting design parameters, the value range of the bottom resistance line, hole spacing, row spacing, super-deep length, filling length, and explosive unit consumption parameters is determined by the empirical formula;

[0020] Step 4.2: Three variables are selected as the three levels of the orthogonal experiment within the value range of each parameter, and finally a 6-factor 3-level orthogonal test scheme is designed;

[0021] Step 4.3: The upper and lower partition charging structure and the hole-by-hole initiation method are used to further optimize the scheme, with a 15ms delay between holes and no delay within the hole, and the total calculation time is 80ms;

[0022] Step 4.4: According to the blasting design parameters in the orthogonal test scheme, the Hypermesh three-dimensional modeling software is used to establish the blasting area model one by one, output the K file, and then perform simulation calculation;

[0023] Step 4.5: The effective stress peak values of the monitoring points in different simulation results are counted, and the range analysis method is used to compare and analyze different simulation results, and the range of different blasting design parameters under the orthogonal table is obtained, so as to obtain the influence degree of different parameters on the large block rate after blasting, and then obtain a set of blasting parameter combination with the best blasting effect.

[0024] Preferably, the numerical simulation verification of the optimal blasting design scheme in step 5 is carried out, and the blasting parameters obtained after optimization are verified by numerical simulation, and the pros and cons of the blasting effect are evaluated by the change of the effective stress peak value of the monitoring points.

[0025] Compared with the prior art, the method has the beneficial effects that: compared with the prior art, the method can comprehensively consider the influence of geological conditions, blasting parameters and various factors on the blasting size by simulating the blasting process through the numerical calculation method, can analyze the advantages and disadvantages of the blasting quality of different blasting schemes through the blasting numerical simulation result, meanwhile, the method does not need to carry out a large number of field tests, reduces the engineering cost, shortens the test period, and improves the work efficiency; in addition, through the reasonable determination of the blasting size, the blasting design parameters can be optimized, the large block rate and the small block rate can be reduced, the work efficiency of the subsequent process can be improved, the engineering cost can be reduced, and the influence of the blasting operation on the surrounding environment can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a method flowchart of the present application;

[0027] Figure 2 is a method principle diagram of the present application;

[0028] Figure 3 is a bench model diagram of the present application;

[0029] Figure 4 is a stress nephogram of the existing blasting scheme bench blasting of the present application;

[0030] Figure 5 is a position diagram of the monitoring point in the model of the present application;

[0031] Figure 6 is a stress time-history curve diagram of the monitoring point of the existing blasting scheme of the present application;

[0032] Figure 7 is a comparison diagram of the optimization of the hole charging structure of the present application;

[0033] Figure 8 is a stress nephogram of the optimal blasting scheme bench blasting of the present application;

[0034] Figure 9 is a stress time-history curve diagram of the monitoring point of the optimal blasting scheme of the present application. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0036] Please refer to Figures 1-5In order to facilitate the understanding of the present application, the specific embodiments of the present application are further described in detail below in combination with the drawings and embodiments. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application. On the contrary, the purpose of providing the embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0037] The present embodiment is a reasonable blasting fragmentation determination method based on numerical calculation, which comprises the following steps as shown in Figure 1 and Figure 2 .

[0038] Step 1: Collect the existing blasting design parameters of the blasting area and the rock sample, and obtain the basic mechanical parameters of the rock through laboratory mechanical test.

[0039] In the present embodiment, the basic mechanical parameters of the rock obtained by test are shown in Table 1 and Table 2, and the existing blasting design parameters include step height, bottom resistance line, hole arrangement mode, hole diameter, hole spacing, row spacing, overdeep length, filling length, explosive unit consumption, charging length, initiation mode, initiation time difference, explosive type, etc. The existing blasting design parameters are shown in Table 3.

[0040] Table 1 CMN rock stratum material parameters

[0041]

[0042] Table 2 copper-containing ore rock material parameters

[0043]

[0044] Table 3 existing blasting design parameters

[0045]

[0046] Step 2: According to the existing blasting design parameters, a step model of the blasting area is established, and pretreatment is carried out, the model material parameters, multi-substance material relationship, non-reflecting boundary condition, calculation result output interval, calculation time length are set, and K file is output.

[0047] Step 2.1: According to the existing blasting design parameters (step height, bottom resistance line, hole arrangement mode, hole diameter, hole spacing, row spacing, overdeep length, filling length, explosive unit consumption, charging length, initiation mode, initiation time difference, explosive type), a step model of the blasting area is established by using Hypermesh three-dimensional modeling software, and the grid is divided. For the parts with larger blasting influence area, coarser grid can be used, and for the key areas near the blasting hole, finer grid is used to improve the calculation accuracy.

[0048] In the embodiment, the grid size near the blast hole is 0.3 m, the grid size of the rest is 0.4 m, and the stepped model is as shown in Figure 3

[0049] Step 2.2: The divided grid units are respectively assigned with corresponding material constitutive models and material parameter attributes, *MAT_PLASTIC_KINEMATIC is selected as the constitutive model of the rock material, *MAT_HIGH_EXPLOSIVE_BURN is selected as the constitutive model of the explosive material, and *EOS_JWL is used to define the state equation of the explosive, which can well describe the relationship among the pressure, density and specific internal energy in the explosive explosion process, at the same time, the no-reflection boundary condition is set for the other side surfaces of the model step except the top surface and the slope surface, so as to simulate that the explosive stress generated in the blasting area can be infinitely outwardly transmitted in the surrounding rock which is in contact with the explosive stress, and the multi-material material relationship, the fluid-structure coupling relationship, and the solving time and the output calculation result time interval of the whole simulation process are set, and finally the K file is outputted;

[0050] In the embodiment, the state equation of the explosive material is shown in the formula, and the detailed parameters of the explosive are shown in Table 4.

[0051] (1)

[0052] In the formula: P — blast pressure, Pa;

[0053] A, B, R 1 、R 2 , ω — explosive material parameters;

[0054] V — relative volume;

[0055] E 0 — initial internal energy, Pa;

[0056] Table 4 Detailed parameters of explosive

[0057]

[0058] Step 3: The existing blasting scheme is numerically simulated by using the LS-DYNA numerical simulation software, and the simulation result is analyzed based on the Von Mises stress failure criterion.

[0059] Step 3.1: The K file is simulated and calculated by using the LS-DYNA finite element numerical simulation software, and the numerical simulation result is viewed by using the LS-Prepost software;

[0060] ​In the present embodiment, the stress cloud diagram of the existing bench blasting scheme is as shown in Figure 4

[0061] Step 3.2: The monitoring points are arranged at the positions where large blocks are prone to be generated in the bench model blasting, the change of the regional energy in the blasting process is determined by checking the propagation process of the blasting stress in the rock and the stress change curve of the monitoring points in the blasting process, the Von Mises stress failure criterion is adopted, the peak value of the effective stress borne by the monitoring points in the blasting process is compared with the tensile strength of the rock, if it is greater than the tensile strength of the rock, it is proved that the rock is damaged in the blasting process, otherwise, it is not damaged.

[0062] In the present embodiment, the positions of the monitoring points in the model are as shown in Figure 5 The stress time-history curve of the monitoring points in the existing blasting scheme is as shown in Figure 6 The peak value statistics of the stress of the monitoring points in the existing blasting scheme are shown in Table 5.

[0063] Table 5 Peak value statistics of the stress of the monitoring points in the existing blasting scheme

[0064]

[0065] Step 4: The blasting parameter optimization based on the orthogonal test, the numerical simulation of the blasting process and the determination of the optimal blasting design scheme by using the range analysis method.

[0066] Step 4.1: According to the existing blasting design parameters, the value range of the parameters such as the bottom resistance line, the hole spacing, the row spacing, the super-deep length, the filling length and the unit consumption of explosives is determined by the empirical formula;

[0067] Bottom resistance line: (2)

[0068] Hole spacing: (3)

[0069] Row spacing: (4)

[0070] Super-deep length: (5)

[0071] Filling length: (6)

[0072] Unit consumption of explosives: The unit consumption of explosives in the existing blasting scheme is 0.31 kg / m 3 , on this basis, the optimization is carried out, which is 0.30 kg / m 3 , 0.31 kg / m 3 and 0.32 kg / m 3 .

[0073] In the above formula: H ​is the step height;

[0074] m is the blast hole density coefficient, and the value range is 0.8-1.4;

[0075] d is the blast hole diameter;

[0076] In the embodiment, the value range of each parameter is shown in Table 6.

[0077] Table 6 Value range of each blasting parameter according to an empirical formula

[0078]

[0079] Step 4.2: three variables are selected as three levels of the orthogonal experiment in the value range of each parameter, and finally a 6-factor 3-level orthogonal experiment scheme is designed;

[0080] In the embodiment, the orthogonal experiment factor level table and the orthogonal experiment scheme are shown in Table 7 and Table 8 respectively.

[0081] Table 7 Orthogonal experiment factor level table

[0082]

[0083] Table 8 Orthogonal experiment scheme

[0084]

[0085] Step 4.3: the scheme is further optimized by using the upper and lower separation charging structure and the hole-by-hole initiation mode, the inter-hole delay is 15 ms, there is no delay in the hole, and the total calculation time is 80 ms;

[0086] In the embodiment, the comparison before and after the optimization of the blast hole charging structure is shown in Table 9. Figure 7

[0087] Step 4.4: according to the blasting design parameters in the orthogonal experiment scheme, the Hypermesh three-dimensional modeling software is used to establish the blasting area model one by one, output the K file, and then perform simulation calculation;

[0088] In the embodiment, the Hypermesh three-dimensional modeling software is used to establish the blasting area model one by one, assign material parameters, set boundary conditions, set multi-material material relationship, fluid-structure coupling relationship, and the solution time of the whole simulation process and the time interval of output calculation results, and finally output the K file.

[0089] ​Step 4.5: The effective stress peak values of the monitoring points in the simulation results of different schemes are statistically analyzed, the simulation results of different schemes are compared and analyzed by using the range analysis method, the range of different blasting design parameters under the orthogonal table is obtained, and the influence degree of different parameters on the large block rate after blasting is obtained, and then a set of optimal blasting parameter combination is obtained.

[0090] In the embodiment, the effective stress peak values of the monitoring points in the simulation results of different schemes are shown in Table 9, the simulation result analysis by the range method is shown in Table 10, and the influence degree of the blasting parameters on the bench blasting effect is shown in Table 11.

[0091] Table 9 Effective stress peak values of monitoring points in simulation results of different schemes

[0092]

[0093] Table 10 Analysis table of simulation results by range method

[0094]

[0095] Table 11 Influence degree of blasting parameters on bench blasting effect

[0096]

[0097] The optimal levels of the blasting parameters are selected by combining Table 10 and Table 11, the level of the bottom resistance line is 1, the level of the hole spacing is 2, the level of the row spacing is 1, the level of the overburden is 1, the level of the filling length is 1, and the level of the explosive unit consumption is 1; that is, the bottom resistance line is 9.5 m, the hole spacing is 9 m, the row spacing is 6 m, the overburden is 2.0 m, the filling length is 5 m, and the explosive unit consumption is 0.3 kg / m 3 .

[0098] Step 5: Verification of the optimal blasting design scheme based on numerical simulation and evaluation of the blasting effect improvement.

[0099] In the embodiment, the optimized blasting parameters are verified by numerical simulation, and the pros and cons of the blasting effect are evaluated by the change of the effective stress peak value of the monitoring points. The stress nephogram of the optimized scheme of bench blasting is shown in Figure 8 , the stress time history curve of the monitoring points of the optimized scheme is shown in Figure 9 , and the stress peak value statistics of the monitoring points of the optimal blasting scheme are shown in Table 12.

[0100] Table 12 Stress peak value statistics of monitoring points of optimal blasting scheme

[0101]

[0102] The stress peak value of the monitoring point obtained from step 5 is compared with the stress peak value of the monitoring point obtained from the existing blasting scheme. Compared with the original scheme, the effective stress mean value of the slope top monitoring point increases by 79.5%, and the effective stress mean value of the slope bottom monitoring point increases by 20.3%. This can effectively eliminate the appearance of large blocks after blasting, and at the same time, it is less than the effective stress mean value of the orthogonal test scheme 1, preventing the rock from being excessively broken, and meeting the requirements of reasonable block size. Therefore, the block size corresponding to the current blasting design parameters is a reasonable blasting block size.

[0103] The reasonable blasting block size determination method is as follows: according to the Von Mises stress failure criterion, if the effective stress peak value of the monitoring point during the explosion process is greater than the tensile strength of the rock, it is proved that the rock is damaged during the explosion process, otherwise, it is not damaged; compared with the stress peak value of the monitoring point obtained from the existing blasting scheme, the effective stress mean value of the slope top monitoring point obtained from the optimal blasting parameter combination based on the range analysis method increases by 79.5%, and the effective stress mean value of the slope bottom monitoring point increases by 20.3%. This can effectively eliminate the appearance of large blocks after blasting, and at the same time, it is less than the effective stress mean value of the orthogonal test scheme 1, preventing the rock from being excessively broken, and meeting the requirements of reasonable block size. Therefore, the block size corresponding to the optimized blasting design parameters is a reasonable blasting block size.

[0104] Explanation of related professional terms:

[0105] Blasting block size: refers to the size and distribution of rock broken blocks after blasting, which is an important indicator for measuring blasting effect;

[0106] Constitutive model: a mathematical model describing the mechanical behavior of materials, used to reflect the relationship between stress, strain, deformation, etc. of materials under stress;

[0107] State equation: an equation describing the relationship between physical properties of a substance under different states (such as pressure, temperature, density, etc.), which is used here to describe the state change during the explosion of explosives;

[0108] Non-reflective boundary condition: in blasting numerical simulation, in order to avoid the reflection of boundary on blasting stress wave, a kind of boundary treatment method is set, so that the blasting stress wave can pass through the boundary without reflection, simulating the infinite domain condition;

[0109] Fluid-structure interaction: refers to the interaction and influence between fluid and solid, which is used in this scheme to describe the mechanical interaction between the fluid generated by the explosion of explosives and the solid rock;

[0110] Orthogonal test: a test design method for studying multiple factors and multiple levels, which obtains comprehensive test information with fewer test times by reasonably arranging the test, and analyzes the influence of each factor on the test result;

[0111] Range analysis: a method for analyzing the results of orthogonal test, by calculating the range to determine the influence of each factor on the test index, and then determine the optimal level combination;

[0112] Von Mises stress: an equivalent stress for judging whether the material will yield and destroy under complex stress state, which is used in this scheme to judge whether the rock will be destroyed due to blasting stress.

[0113] Finally, it should be noted that: the above implementation is only used to the technical solutions of the present application, rather than limit; although the present application is described in detail with reference to the foregoing examples, those skilled in the art should understand that: it still can modify the technical solutions recorded in the foregoing examples, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope defined by the claims of the present application.

Claims

1. A method for determining the appropriate blasting block size based on numerical calculation, characterized in that: Includes the following steps: Step (1): Collect existing blasting design parameters and rock samples in the blasting area, and obtain the basic mechanical parameters of the rock through laboratory mechanical testing; Step (2): Based on the existing blasting design parameters, establish a step model of the blasting area, and at the same time perform preprocessing, set the model material parameters, multi-material relationships, non-reflective boundary conditions, calculation result output interval, calculation time, and output K file; Step (3): Use LS-DYNA numerical simulation software to perform numerical simulation of the existing blasting scheme, and analyze the simulation results based on the VonMises stress failure criterion. Step (4): Optimize blasting parameters based on orthogonal experiments, numerically simulate the blasting process, and determine the optimal blasting design scheme using range analysis. Step (5): Verification of the optimal blasting design scheme based on numerical simulation and evaluation of its blasting effect improvement; Step (3) includes: Step 3.1: Perform simulation calculations on the K file using LS-DYNA finite element numerical simulation software, and view the numerical simulation results using LS-Prepost software; Step 3.2: Set up monitoring points in locations prone to large blocks during the step model blasting. By observing the propagation process of the explosion stress in the rock during the blasting process and the stress change curves at the monitoring points, determine the regional energy changes during the blasting process. Use the Von Mises stress failure criterion to compare the effective stress peak value experienced by the monitoring point during the explosion with the tensile strength of the rock. If it is greater than the tensile strength of the rock, it proves that the rock was damaged during the explosion; otherwise, it was not damaged. Step (4) includes: Step 4.1: Based on the existing blasting design parameters, determine the range of values ​​for the chassis resistance line, hole spacing, row spacing, extra-depth length, filling length, and explosive consumption parameters using empirical formulas; Step 4.2: Select three variables within the range of each parameter value as the three levels of the orthogonal experiment, and finally design a six-factor, three-level orthogonal experimental scheme; Step 4.3: The scheme is further optimized by adopting an upper and lower separated charge structure and a hole-by-hole initiation method. The inter-hole delay is 15ms, and there is no delay within the hole. The total calculation time is 80ms. Step 4.4: Based on the blasting design parameters in the orthogonal experimental scheme, use Hypermesh 3D modeling software to build blasting area models one by one, output K-files, and then perform simulation calculations; Step 4.5: Statistically analyze the effective stress peak values ​​of monitoring points in the simulation results of different schemes, and use the range analysis method to compare and analyze the different simulation results to obtain the range of different blasting design parameters under the orthogonal table, thereby obtaining the degree of influence of different parameters on the large block ratio after blasting, and then obtaining a set of blasting parameter combinations with the best blasting effect. The optimal blasting design scheme in step (5) is verified by numerical simulation. The optimized blasting parameters are verified by numerical simulation, and the blasting effect is evaluated by the change of the effective stress peak at the monitoring point.

2. The method for determining reasonable blasting block size based on numerical calculation according to claim 1, characterized in that: The existing blasting design parameters in step (1) include step height, base resistance line, hole layout, hole diameter, hole spacing, row spacing, ultra-deep length, filling length, explosive consumption, charge length, detonation method, detonation time difference, and explosive type. The basic mechanical parameters of the rock include rock density, elastic modulus, Poisson's ratio, uniaxial compressive strength, and tensile strength.

3. The method for determining reasonable blasting block size based on numerical calculation according to claim 1, characterized in that: Step (2) includes: Step 2.1: Based on the existing blasting design parameters, use Hypermesh 3D modeling software to establish a step model of the blasting area and divide it into meshes. For areas with a large blasting impact area, use coarser meshes, and for critical areas near the blasting holes, use finer meshes to improve calculation accuracy. Step 2.2: Assign corresponding material constitutive models and material parameter properties to the divided mesh elements. Select *MAT_PLASTIC_KINEMATIC as the constitutive model for rock material and *MAT_HIGH_EXPLOSIVE_BURN as the constitutive model for explosive material. Define the state equation of the explosive using *EOS_JWL. This equation can well describe the relationship between pressure, density, and specific internal energy during the explosive explosion process. At the same time, set non-reflective boundary conditions on the other sides of the model steps, except for the top and slope surfaces, to simulate the infinite outward propagation of the explosive stress generated in the blasting area within the surrounding rock. Set the multi-material relationships, fluid-structure interaction relationships, and the time interval between the solution time and the output of the calculation results for the entire simulation process. Finally, output the K file.

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