Rock burst numerical simulation method, electronic device and storage medium

Abstract

The application provides a rock burst numerical simulation method, an electronic device and a storage medium. The rock burst numerical simulation method is executed in the electronic device, and the method comprises the following steps: generating smooth particles indicating a tunnel rock mass structure to obtain a tunnel model; setting element parameters of the tunnel model, wherein the element parameters at least include boundary conditions of the model and initial positions, velocities, densities and material parameters of the particles; updating a smooth kernel function based on interaction relationships between the smooth particles; determining damage particles in the particles based on the smooth kernel function and preset particle change parameters; converting the damage particles into discrete element particles; determining a particle numerical function based on relationships between the smooth particle pairs, the smooth particles and the discrete element particles, and the discrete element particle pairs; and calculating numerical values of the particles in the current tunnel model by using the particle numerical function, so as to obtain a rock burst numerical simulation result.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel rockburst, and particularly relates to a rockburst numerical simulation method, an electronic device and a storage medium. BACKGROUND

[0002] Rockburst, also known as rock burst, is a dynamic phenomenon of sudden and violent destruction of the rock mass around the wellbore or working face due to the instantaneous release of elastic deformation energy, often accompanied by phenomena such as coal and rock ejection, loud noise and air blast.

[0003] There is no deep hard rock engineering excavation or mining, and there is no rockburst. Rockburst is an engineering geological disaster caused by deep hard rock excavation or mining. Strain rockburst is a dynamic rock failure caused by stress adjustment after internal unloading of deep roadway under high initial stress conditions, and usually occurs in the form of sudden ejection of rock plate at the excavation surface and violent release of strain energy. Generally, deep engineering tunnel excavation unloading will inevitably change the initial stress of the rock mass near the excavation surface, and then change the stress state, induce stress adjustment. In the stress adjustment process of deep roadway, if the maximum tangential stress reaches or exceeds the strength threshold of the surrounding rock, strain rockburst will be induced.

[0004] Rockburst is one of the main safety hazards faced by deep mines. Mild rockburst only has spalling rock pieces without ejection phenomenon, and severe rockburst can measure 4.6 magnitude and 7-8 intensity, which can cause damage to ground buildings and a loud noise. Rockburst can occur suddenly or last for several days to several months. The conditions for rockburst are that the rock mass has high ground stress and exceeds the strength of the rock itself, and the rock has high brittleness and elasticity. Under these conditions, once the original balance of the rock mass is destroyed by underground engineering activities, the energy accumulated in the rock mass will be released, causing rock failure and throwing out broken rock.

[0005] Therefore, it is urgent to develop a new numerical simulation method for the rockburst process of deep buried tunnels to accurately reflect the sudden ejection of rock plate at the excavation surface and the violent release of stress. SUMMARY

[0006] Therefore, the purpose of the present application is to provide a rockburst numerical simulation method, an electronic device and a storage medium which overcome the above problems or at least partially solve the above problems.

[0007] To achieve the above purpose, the first aspect of the present application provides a rockburst numerical simulation method, comprising:

[0008] generating smooth particles indicating the structure of the tunnel rock mass to obtain a tunnel model;

[0009] setting element parameters of the tunnel model, the element parameters at least including boundary conditions of the model and initial positions, velocities, densities and material parameters of the particles.

[0010] updating the smoothing kernel function based on the interaction relationship between the smooth particles;

[0011] determining a damaged particle in each particle based on a preset particle change parameter by using the smoothing kernel function;

[0012] converting the damaged particle into a discrete element particle;

[0013] determining a particle numerical function based on the relationship between the smooth particle pairs, the smooth particle and the discrete element particle, and the discrete element particle pairs;

[0014] calculating the numerical value of each particle in the current tunnel model by using the particle numerical function as the rock burst numerical simulation result.

[0015] Optionally, the numerical value data of each particle in the current tunnel model is calculated by using the particle numerical function, and the numerical value data at least includes the final position, the velocity, and the stress of the particle, including:

[0016] For each particle to be calculated, the corresponding variable parameter is calculated according to a preset time step, and the variable parameter at least includes the position, the velocity, and the density. After obtaining the variable parameter each time, the element parameter of the particle in the tunnel model is updated based on the current variable parameter, and the steps of constructing the smoothing kernel function, converting the particle type, determining the particle numerical function, and calculating the numerical value are repeatedly executed until all time steps are completed.

[0017] Optionally, the variable parameter of each particle is calculated by the following formula:

[0018]

[0019] wherein t and t0 are the calculation time and the initial time respectively, Δt is the calculation time step, ρ is the density of the particle, v is the velocity of the particle, and x is the position coordinate of the particle.

[0020] Optionally, the interaction relationship between the smooth particles is expressed by the following formula:

[0021]

[0022] wherein i is the serial number of the particle, j is the serial number of the adjacent particle, N is the total number of the particles, f(x j ) is the field function of the base particle i, and is the derivative of the field function of the base particle i, ρ is the particle density, m is the particle mass, h is the smoothing kernel radius of the influence range of the base particle i, W(x i -x j , h) is the smoothing kernel function, is the gradient of the smoothing kernel function.

[0023] Optionally, the updated smoothing kernel function is expressed by the following formula:

[0024]

[0025] wherein R=x i -x j , represents the distance between particle i and particle j, wherein λ is a proportional factor of the dimension of the kernel function space, and in a two-dimensional space

[0026] Optionally, the preset particle variation parameter includes density variation, internal force variation and stress variation.

[0027] Optionally, the density variation is expressed by the following formula:

[0028]

[0029] The internal force variation is expressed by the following formula:

[0030] σ αβ =-pδ αβ +S αβ ,

[0031] The stress variation is expressed by the following formula:

[0032]

[0033] wherein α and β represent x, y and z values under the Cartesian coordinate system, σ represents the Cauchy stress tensor, f i α is the external force of the basic particle, δ αβ is the Dirac function, Π ij is the artificial viscosity, T ij is the artificial stress, P is the isotropic pressure, and S is the deviatoric stress, p H (ρ) represents the Hugoniot curve function, Γ is the Grüneisen parameter, ρ0 is the initial particle density, ρ is the current particle density, ε γγ =ε xx +ε yy +ε zz , ε αβ is the strain rate tensor, which is defined as: ω βγ and ω αγ are the torsion rate tensors, and

[0034] Optionally, the damaged particles in each particle are determined based on preset particle change parameters by using the smooth kernel function, including:

[0035] The particle change parameters are updated based on the smooth kernel function.

[0036] The stress value of each particle is calculated based on the updated particle change parameters.

[0037] It is determined whether the calculated stress value of the particle satisfies the Mohr-Coulomb criterion with tensile cut-off, and if yes, the particle is determined as a damaged particle.

[0038] Optionally, the updated particle change parameters are expressed by the following formula:

[0039]

[0040] wherein U represents an undamaged particle, represents a damaged particle, and W ij (x i -x j ,h) is the smooth kernel function and its gradient of the undamaged particle, is the smooth kernel function and its gradient of the damaged particle.

[0041] Optionally, the Mohr-Coulomb criterion is expressed by the following formula:

[0042]

[0043] wherein σ n and τ n are tensile stress and shear stress, σ t and τ t are tensile strength and shear strength, σ1 is the maximum principal stress, σ3 is the minimum principal stress, c is the cohesion of the rock, and φ is the internal friction angle.

[0044]

[0045] In a second aspect, the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method according to the first aspect.

[0046] In a third aspect, the present application provides a non-transitory computer readable storage medium storing computer instructions for causing a computer to execute the method according to the first aspect.

[0047] From the above, it can be seen that the rock burst numerical simulation method, electronic device and storage medium provided by the application couple the smoothed particle hydrodynamics (SPH) and the discrete element method (DEM) method, utilize the conversion of the smoothed particles to the discrete element particles to simulate the change process of the rock mass structure in the rock burst process, accurately capture the whole process of the crack initiation and expansion, contact formation, frictional slip and complete destruction of the tunnel, realize the conversion from the continuous domain to the discontinuous domain under the single SPH framework, and can significantly improve the calculation efficiency, and is suitable for different scale tunnel engineering problems.

[0048] The above description is only a summary of the technical scheme of the application, in order to more clearly understand the technical means of the application, and can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the specific embodiments of the application are described below. BRIEF DESCRIPTION OF DRAWINGS

[0049] In order to more clearly illustrate the technical scheme in the application or related art, the drawings needed in the embodiment or related art description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the application, and those skilled in the art can obtain other drawings according to these drawings without creating any creative labor.

[0050] Figure 1 The rock burst numerical simulation method 200 flowchart of the embodiment of the application;

[0051] Figure 2 The tunnel model result schematic diagram of one embodiment of the application;

[0052] Figure 3 The rock burst damage process particle change schematic diagram of one embodiment of the application;

[0053] Figure 4 The tunnel model result schematic diagram of another embodiment of the application;

[0054] Figure 5 The rock burst damage process particle change schematic diagram of another embodiment of the application;

[0055] Figure 6 The electronic device schematic diagram of the embodiment of the application. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical scheme and advantages of the application more clear and obvious, the application will be further described in detail below in combination with specific embodiments and with reference to the drawings.

[0057] It should be noted that the technical terms or scientific terms used in the embodiments of the present application should be understood as the general meaning understood by those skilled in the art to which the embodiments of the present application belong, unless otherwise defined. The terms "first", "second", and similar terms used in the embodiments of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. The terms "include" or "contain" and similar terms mean that the elements or objects before the terms cover the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right" and the like are only used to represent relative positional relationships, and when the absolute positions of the described objects change, the relative positional relationships may also change accordingly.

[0058] Numerical simulation is a useful tool to reveal the rockburst mechanism of deep buried tunnels. However, the traditional finite element method and finite difference method can usually only simulate small deformation of the tunnel due to grid limitations, and cannot truly simulate the entire process of cracking and failure of the rock mass. For example, the discrete element method (DEM) and the discontinuous deformation analysis method (DDA) have many mesoscopic parameters that have no practical significance, require a large amount of artificial calibration, and have relatively low computational efficiency, making them difficult to apply to engineering practice.

[0059] To solve the problems in the prior art, the scheme of the present application is proposed. An embodiment of the present application provides a rockburst numerical simulation method, which is based on the theoretical framework of smoothed particle hydrodynamics (SPH) and forms a Hybrid SPH-DEM method. Compared with the traditional SPH method, GPD method and DEM method, the Hybrid SPH-DEM method utilizes the dual advantages of SPH and DEM. The former establishes continuous stress, similar to FEM-DEM, which can greatly improve the computational efficiency, and most of the parameters have practical physical significance, so that the simulation of micro parameters on macroscopic fracture damage can be realized by only adjusting the cohesion, internal friction angle and tensile strength. The latter makes it possible to simulate large deformation with contact, which cannot be achieved by the traditional single SPH method. The main advantage of the Hybrid SPH-DEM method over the advanced FDEM algorithm is the convenience of subsequent development of coupling functions, such as the strong function of SPH in simulating non-Newtonian fluids. Through the unified SPH framework, the coupling of WCSPH and Hybrid SPH-DEM can be realized, thereby realizing the water and mud inrush, landslide surge and the like of the tunnel. Moreover, since part of the rock mass is also simulated by the SPH-DEM coupling method, it becomes a way to solve the rock fracture problem under multi-phase conditions, and has strong development potential.

[0060] Figure 1 FIG. 1 shows a flowchart of a rockburst numerical simulation method 200 according to an embodiment of the present application. As shown in FIG. 1, the rockburst numerical simulation method 200 includes the following steps.Figure 1

[0061] The purpose of the method 200 is to realize a new means for numerical simulation of deep-buried tunnel rock burst process, so as to accurately reflect the method of sudden ejection of rock plate at the excavation face and the characteristics of stress release. In step 202, smooth particles indicating the structure of the tunnel rock mass are generated to obtain a tunnel model. Exemplarily, the tunnel model can be generated in the following manner. First, 1 layer of type I virtual particles are arranged outside the boundary of the model to play a role in maintaining the shape of the boundary. Second, 2 layers of type II virtual particles are generated by mirroring the type I virtual particles as the mirror boundary, wherein the parameters such as density, velocity and pressure of the type II virtual particles are the same as those of the real particles; and the parameters such as density, vertical velocity and pressure of the type I virtual particles are calculated.

[0062] In step 204, the element parameters of the tunnel model are set, including at least the boundary conditions of the model and the initial position, velocity, density and material parameters of each particle. The material parameters mainly include the elastic modulus, Poisson's ratio, cohesive force, tensile strength and internal friction angle. The boundary conditions can include fixing the boundary with three layers of base particles to ensure that there is no truncation error of the particles at the boundary during integration.

[0063] According to the above example, the average horizontal stress σx of the model is gradually increased to P0 and then kept basically unchanged by adjusting the horizontal position of the type I virtual particles.

[0064] The expression of the horizontal velocity v x (σ x ) is

[0065]

[0066] In the formula, v0 and v1 are given velocity values, "+" represents loading, and "-" represents unloading.

[0067] It is worth noting that through several verifications, the size of the loading speed needs to be adjusted according to the elastic modulus of the material point. When the elastic modulus of the material point is large, the loading speed needs to be reduced, and the number of steps required to reach the pre-stress will be longer.

[0068] In step 206, the smooth kernel function is updated based on the interaction relationship between the smooth particles.

[0069] Specifically, the interaction relationship between the smooth particles is expressed by the following formula:

[0070]

[0071] Wherein, i is the serial number of the particle, j is the serial number of the adjacent particle, N is the total number of particles, f(x j ​) is the field function of the base particle i, and is the derivative of the field function of the base particle i, p is the particle density, m is the particle mass, h is the smoothing kernel radius of the influence range of the base particle i, W(x i -x j is a smoothing kernel function, is the gradient of the smoothing kernel function.

[0072] The updated smoothing kernel function is expressed by the following formula:

[0073]

[0074] wherein R=x i -x j , represents the distance between particle i and particle j, wherein λ is a proportional factor of the dimension of the kernel function space, and is

[0075] In step 208, the damaged particles in each particle are determined based on the preset particle change parameters by using the smoothing kernel function. The preset particle change parameters include density change, internal force change and stress change.

[0076] Specifically, the particle change parameters can be updated based on the smoothing kernel function.

[0077] wherein the density change before updating is expressed by the following formula:

[0078]

[0079] The internal force change is expressed by the following formula:

[0080] σ αβ =-pδ αβ +S αβ ,

[0081] The stress change is expressed by the following formula:

[0082]

[0083] wherein α and β represent the x, y and z values in the Cartesian coordinate system, σ represents the Cauchy stress tensor, f i α is the external force of the base particle, δ αβ is the Dirac function, Π ij is the artificial viscosity, T ij is the artificial stress, P is the isotropic pressure, and S is the deviatoric stress, p H (ρ) represents the Hugoniot curve function, Γ is the Grüneisen parameter, p0 is the density of initial particles, p is the current particle density, ε γγ = ε xx + ε yy + ε zz , ε αβ is the strain rate tensor, which is defined as: ω βγ and ω αγ is the twist rate tensor, and

[0084] The updated particle change parameters are expressed by the following formula:

[0085]

[0086] wherein U represents an undamaged particle, represents a damaged particle, and in the formula, W ij = W(x i -x j , h) is a non-calculated smoothing kernel function and its gradient, is a damaged particle smoothing kernel function and its gradient.

[0087] Then, based on the updated particle change parameters, the stress value of each particle is calculated.

[0088] Finally, it is judged whether the calculated stress value of the particle satisfies the Mohr-Coulomb criterion with tensile cut-off. If it satisfies, the particle is determined to be a damaged particle.

[0089] The Mohr-Coulomb criterion is expressed by the following formula:

[0090]

[0091] σ n and τ n are the tensile stress and shear stress, σ t and τ t are the tensile strength and shear strength. σ1 is the maximum principal stress, σ3 is the minimum principal stress, c is the cohesion of rock, and φ is the internal friction angle.

[0092] In actual application, a parameter f can be introduced to improve the derivative of the kernel function. When the local particle satisfies the above Mohr-Coulomb failure criterion, f = 0; when the local particle does not satisfy the above Mohr-Coulomb failure criterion, f = 1.

[0093] In step 210, the damaged particle is converted into a discrete element particle.

[0094] Specifically, the damaged particles are first converted into non-continuous particles, each damaged particle corresponds to one non-continuous particle (DP) (Fig 2(c)); then, since it is instantaneous transformation, the fracture surface is converted into the contact surface.

[0095] In one specific example, the SPH method is based on local stress concentration. Therefore, by introducing a reasonable strength failure criterion, when the stress concentration reaches the failure criterion, the SPH particle will be converted into a DEM particle.

[0096] The mass and momentum of the SPH particle that meets the strength criterion are also converted into the momentum and mass of the DEM particle, and at this moment, the DEM particle that has been converted constitutes the fracture plane; subsequently, the contact law is established between the SPH particle that has not been converted into the fracture and the DEM particle that has been converted. This process enables the block composed of SPH particles to have contact slip and failure along the fracture plane formed by DEM. The coupling range of SPH (or the size of the element) should be similar to the size of the DEM particle. At each calculation step, the stress value of the SPH particle is checked. When the stress condition of SPH meets the Mohr-Coulomb criterion with tensile cutoff (considered to be damaged. At this point, the number of "virtual bonds" within the non-local influence domain of the i-th SPH particle is broken), a damage coefficient is established to quantitatively describe the damage degree of the particle, which is as follows:

[0097] D f =N damage_bonds / N total_bonds ,

[0098] where N damage_bonds represents the number of damaged bonds of any particle within the influence domain, and N total_bonds represents the total number of virtual bonds of any particle within the influence domain. In order to solve the cracking behavior of rock, the Mohr-Coulomb criterion with tensile cutoff is used to determine the initiation and propagation of cracks. The Mohr-Coulomb criterion with tensile cutoff is expressed as:

[0099] σ1≥R t ,

[0100] τ=1 / 2(σ1-σ3)×cosφ≥τ t =c+σ t tanφ,

[0101] where R t and τ t represent the tensile strength and shear strength on the failure surface, and σ tand τ denote the normal and shear stresses on the failure surface, respectively. σ1 and σ3 denote the maximum and minimum principal stresses, respectively. c denotes the cohesion, and φ denotes the internal friction angle. After cracking, a contact strategy following Newton's second law is proposed to realize the contact behavior of rock blocks along the fracture surface (i.e., frictional sliding and top failure). Damaged SPH particles are converted into DEM particles.

[0102] In step 212, a particle numerical function is determined based on the relationship between pairs of smooth particles, pairs of discrete elements and pairs of discrete elements.

[0103] Specifically, the particle numerical function is expressed by the following formula:

[0104]

[0105] In step 214, the numerical values of the particles in the current tunnel model are calculated using the particle numerical function as the rock burst numerical simulation result.

[0106] Specifically, for each particle to be calculated, the corresponding variable parameters of the particle are calculated according to a preset time step, the variable parameters at least including position, velocity and density, and after each variable parameter is obtained, the element parameters of the particle in the tunnel model are updated based on the current variable parameters, and the steps of constructing the smooth kernel function, converting the particle type, determining the particle numerical function and calculating the numerical value are repeatedly executed until all time steps are completed.

[0107] wherein the variable parameters of each particle are calculated by the following formula:

[0108]

[0109] wherein t and t0 are the calculation time and the initial time, respectively, Δt is the calculation time step, ρ is the density of the particle, v is the velocity of the particle, and x is the position coordinate of the particle.

[0110] It should be noted that since the present application relates to the instantaneous excavation of a tunnel, the SPH particle dormancy method is proposed to represent the excavation within the tunnel, similar to the near-field dynamics method, the excavation range Ω is set i When the particles in the range are considered to be excavated, the material points in the excavation area are placed in a dormant state to eliminate the interaction between the excavation range points and the non-excavation part points, which can be achieved by setting the first derivative of the kernel function of the SPH domain to 0, however, the interaction between the SPH particles in the normal area is not affected, which can be set to different time steps of excavation in the program, and the overall excavation and distributed excavation of the tunnel can be realized, which is not limited in the present application.

[0111] The method provided by the application simulates the change process of the rock mass structure in the rock burst process by coupling smooth particle hydrodynamics (SPH) and discrete element method (DEM), utilizes conversion of smooth particles to discrete element particles, accurately captures the whole process of crack initiation and expansion, contact formation, friction slip and complete destruction of the tunnel, and realizes the conversion from continuous domain to discontinuous domain under the single SPH framework, so that the calculation efficiency can be significantly improved, and the method is suitable for tunnel engineering problems of different scales.

[0112] In one specific example, the following is shown to simulate the operation of the rock burst numerical simulation method of the application:

[0113] A two-dimensional model of a circular tunnel face excavation is established. After the tunnel is excavated, the surrounding rock deforms freely without support, and the mixed SPH-DEM function for fracture and contact is introduced.

[0114] As shown in Figure 2 A square numerical model with a side length of 40 m is established. The tunnel is located at the center of the square model, and the radius is 5.5 m. The influence range after the tunnel is excavated is about 3-5 times the diameter of the tunnel. The numerical model is subjected to symmetrical load, and the size of the model is 40m x 40m. Considering the real stress field of the model, the model is under the pressure of 6.9MPa vertical load and 34.5MPa horizontal load, 6.9MPa in the vertical direction and 34.5MPa in the horizontal direction. The rock sample is uniformly dispersed into 40,000 real particles, and 3,200 virtual particles are arranged outside the boundary of each real particle. The stress is applied to the virtual boundary composed of three layers of virtual particles. The thickness of the numerical model is one layer of real particles, so the model can be regarded as a plane strain problem. The physical and mechanical parameters of the numerical model are selected as follows: the elastic modulus is 18GPa, the Poisson's ratio is 1 / 3, the density is 2600kg / m 3 The excavation is carried out in one time, and the Mohr-Coulomb fracture criterion with tensile cutoff is introduced. The parameters of the SPH-DEM coupling are shown in Table 1. In addition, by introducing the Weibull distribution function, the non-uniformity coefficient of the cohesion value is set to 20. The time step of this simulation is set to 1x10 -5 second. The gravity acceleration is set to 9.8m / s 2 .

[0115] Table 1

[0116]

[0117] The EDZ during tunnel excavation is numerically studied based on the confining pressure application method with adjustable plate loading and particle hibernation technique. It is divided into two steps. First, the initial stress equilibrium is calculated; that is, the deformation and stress state of the stratum under the boundary condition before tunnel excavation is calculated. The confining pressure application method with adjustable plate loading is adopted, and then the particle hibernation method under the stress equilibrium condition is adopted to simulate the tunnel excavation when the solid particles at the boundary reach the required stress.

[0118] In this simulation, 5000 iterations are calculated in the stress equilibrium stage, and 5000 iterations are calculated in the stress re-equilibrium stage after tunnel excavation. As shown in Figure 3 , through the above steps, the tunnel crack initiation and extension process, the damage evolution process of the tunnel, the evolution process of the maximum principal stress distribution of the tunnel, and the test results in the field are obtained.

[0119] As can be seen from the figure, in the case where the lateral stress is greater than the vertical stress, the tunnel model represented by SPH-DEM forms a V-shaped shear spalling at the tunnel vault and the bottom (T=0.55s), and gradually expands into a large V-shaped shear-tension failure (T=0.6s) accompanied by a large amount of rock burst fragments ejected (T=0.6s-1.0s). The damage map and stress feature map clearly show the whole process of brittle rock burst of the rock mass, and by comparing multiple field V-shaped spalling zones, it is shown that the numerical simulation method of the present application is feasible and effective.

[0120] In another specific example, a Jinping tunnel model is established based on the present application to simulate a high-angle fault near the excavation position of the 11.28 rock burst event.

[0121] Unlike the above example, this simulation needs to introduce particle hibernation to simulate a pre-existing fault. After introducing the fault, the model (as shown in Figure 4 ) reaches stress equilibrium before excavation for 5000 steps, and then excavates for an additional 5000 steps. The material parameters of SPH and DEM are described in detail in Table 2. The Mohr-Coulomb failure criterion with tensile cutoff and single excavation are adopted. The stress conditions include σv=61.48 MPa and σh=46.42 MPa are applied. The fault is characterized as smooth and unfilled. At the same time, a uniform Weibull distribution is adopted to construct the heterogeneity. The time step is set to 1×10 -5 seconds, and the gravitational acceleration is kept at 9.8 m / s 2 .

[0122] Table 2

[0123]

[0124] Through the above steps, the fault tunnel crack initiation and extension process is obtained, as shown in Figure 5The damage evolution process of the fault tunnel, the maximum principal stress distribution evolution process of the fault tunnel and the field results of the fault tunnel are obtained.

[0125] As can be seen from the figures, the damage map and the stress characteristic map of the field tunnel are simulated with high fidelity, the whole process of the brittle rock burst of the fault tunnel rock mass is clearly shown, and by comparing the rock burst collapse area of the field on November 28, it is shown that the numerical simulation method of the application is feasible and effective.

[0126] It should be noted that the method of the embodiments of the application can be executed by a single device, such as a computer or a server. The method of the embodiments can also be applied to a distributed scenario, and be completed by multiple devices cooperating with each other. In the distributed scenario, one of the multiple devices can only execute one or more steps in the method of the embodiments, and the multiple devices can interact with each other to complete the method.

[0127] The various techniques described herein can be implemented in connection with hardware or software or, where appropriate, with a combination of both. Thus, the methods and apparatus of the application, or certain aspects or portions thereof, can take the form of program code (i.e., instructions) embodied in tangible media, such as removable hard disks, U disks, floppy diskettes, CD-ROMs, or any other machine-readable storage medium wherein, when the program code is loaded into an internal memory of the machine such as a computer, the machine becomes an apparatus for practicing the application.

[0128] It should be noted that some embodiments of the application have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order and still achieve desirable results. Additionally, the process depicted in the figures does not necessarily require the particular order shown, or sequential order, to achieve the desired results. In certain implementations, multitasking and parallel processing can be advantageous.

[0129] Based on the same technical concept, the application also provides an electronic device corresponding to the numerical simulation method of rock burst of any of the above-mentioned embodiments, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor executes the program to realize the numerical simulation method of rock burst of any of the embodiments.

[0130] Figure 6A more specific electronic device hardware structure schematic diagram provided by the embodiment is shown, and the device can include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040 are connected to each other through the bus 1050 for internal communication.

[0131] The processor 1010 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits, etc., for executing related programs to implement the technical solutions provided by the embodiments of the present specification.

[0132] The memory 1020 can be implemented by a ROM (Read Only Memory), a RAM (Random Access Memory), a static storage device, a dynamic storage device, etc. The memory 1020 can store an operating system and other application programs, and when the technical solutions provided by the embodiments of the present specification are implemented by software or firmware, the related program codes are stored in the memory 1020 and called and executed by the processor 1010.

[0133] The input / output interface 1030 is used to connect input / output modules to realize information input and output. The input / output modules can be configured as components in the device (not shown in the figure) or externally connected to the device to provide corresponding functions. The input device can include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device can include a display, a speaker, a vibrator, an indicator light, etc.

[0134] The communication interface 1040 is used to connect a communication module (not shown in the figure) to realize the communication interaction between the device and other devices. The communication module can realize communication through a wired manner (such as USB, network cable, etc.) or through a wireless manner (such as mobile network, WIFI, Bluetooth, etc.).

[0135] The bus 1050 includes a channel for transmitting information between various components (such as the processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040) of the device.

[0136] It should be noted that although the above device only shows the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040 and the bus 1050, in the specific implementation process, the device can also include other components necessary for normal operation. In addition, those skilled in the art can understand that the above device can also only contain the components necessary to implement the embodiments of the present application, and does not necessarily contain all the components shown in the figure.

[0137] The electronic device of the above embodiment is used to implement the corresponding rock burst numerical simulation method in any of the preceding embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0138] Based on the same technical concept, corresponding to the method of any of the above embodiments, the present application also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to perform the rock burst numerical simulation method according to any of the above embodiments.

[0139] The computer-readable medium of the present embodiment includes permanent and non-permanent, removable and non-removable media, which can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible by a computing device.

[0140] The computer instructions stored in the storage medium of the above embodiment are used to cause the computer to perform the rock burst numerical simulation method according to any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0141] Based on the same inventive concept, corresponding to the rock burst numerical simulation method described in any of the above embodiments, the present disclosure also provides a computer program product including computer program instructions. In some embodiments, the computer program instructions can be executed by one or more processors of a computer to cause the computer and / or the processor to perform the rock burst numerical simulation method. Corresponding to the execution subject of each step in each embodiment of the rock burst numerical simulation method, the processor performing the corresponding step can belong to the corresponding execution subject.

[0142] The computer program product of the above embodiments is used to make the computer and / or the processor execute the rockburst numerical simulation method as described in any of the above embodiments, and has the beneficial effects of the corresponding method embodiments, which are not repeated here.

[0143] Those skilled in the art should understand that the discussion of any embodiment herein is merely exemplary, and is not intended to suggest that the scope of the application (including the claims) is limited to these examples; many modifications, alterations and permutations of the embodiments described herein or of the techniques described herein are possible, and are within the scope of the application, as will be apparent to those skilled in the art. Moreover, the steps of the embodiments described herein can be implemented in any order, and are not limited to the order described herein.

[0144] In addition, to simplify the description and discussion, and so as not to make the embodiments of the application difficult to understand, the well-known power / ground connections with integrated circuit (IC) chips and other components can or can not be shown in the provided drawings. In addition, the apparatus can be shown in the form of a block diagram in order to avoid making the embodiments of the application difficult to understand, and this also takes into account the fact that the details of the implementation of these block diagram apparatus are highly dependent on the platform to be implemented (i.e., these details should be fully within the understanding of those skilled in the art). Where specific details (e.g., circuitry) are set forth in order to describe an illustrative embodiment of the application, it will be apparent to those skilled in the art that the embodiments of the application can be practiced without, or with variations of, these specific details. Thus, the description is to be considered as illustrative and not restrictive.

[0145] Although the application has been described in conjunction with specific embodiments thereof, numerous alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) can use the embodiments discussed.

[0146] The embodiments of the application are intended to cover all such alternatives, modifications, and variations as falling within the broad scope of the appended claims. Accordingly, any one of the steps of the embodiments of the application can be performed in any order, and are not limited to the order described herein.

Claims

1. A numerical simulation method for rockburst, characterized in that, include: Generating smooth particles that indicate the tunnel rock mass structure yields a tunnel model; Set the element parameters of the tunnel model, which include at least the boundary conditions of the model and the initial position, velocity, density, and material parameters of each particle; The smoothing kernel function is updated based on the interaction relationships between the smooth particles. Based on the smooth kernel function, update the change parameters of each particle; Based on the updated particle change parameters, the stress value of each particle is calculated; Determine whether the calculated stress value of the particle satisfies the Mohr-Coulomb criterion with tensile truncation. If it does, then the particle is determined to be a damaged particle; convert the damaged particle into a discrete element particle. Based on the relationship between smooth particle pairs, smooth particles and discrete element particles, and discrete element particle pairs, the particle numerical function is determined. The numerical values ​​of each particle in the current tunnel model are calculated using the particle numerical function, and the results are used as the numerical simulation results of the rockburst. The updated parameters of each particle are expressed by the following formula: ， in, It is the particle's serial number. It is the index of the nearest particle. N It is the total number of particles. It is particle density. It is the particle mass. and In Cartesian coordinates, x, y and z value, Represented as the Cauchy stress tensor, External forces acting on fundamental particles For the Dirac function, Artificial viscosity, For artificial stress, Representing undamaged particles, Represents the damaged particle, in the formula For the uncalculated smooth kernel function and its gradient, The smoothing kernel function and its gradient represent the damaged particles. The Mohr-Coulomb criterion is expressed by the following formula: in, and For tensile stress and shear stress, and These are tensile strength and shear strength. For the maximum principal stress, For the minimum principal stress, For the cohesion of rocks, It is the internal friction angle; The particle numerical function is expressed by the following formula: 。 2. The method according to claim 1, characterized in that, The numerical data of each particle in the current tunnel model is calculated using the aforementioned particle numerical function. This numerical data includes at least the particle's final position, velocity, and stress, including: For each particle to be calculated, its corresponding variable parameters are calculated according to a preset time step. The variable parameters include at least position, velocity and density. After each variable parameter is obtained, the element parameters of the particle in the tunnel model are updated based on the current variable parameters. The steps of constructing a smooth kernel function, converting particle type, determining particle numerical function and calculating value are repeated until all time steps are completed.

3. The method according to claim 1, characterized in that, The variable parameters of each particle are calculated using the following formula: in, t and t 0 represents the calculation time and the initial time, respectively, Δ t To calculate the time step, ρ For the density of particles, v For the velocity of the particle, x These are the particle's position coordinates.

4. The method according to claim 1, characterized in that, The interaction relationships between the smooth particles are expressed by the following formula: ， in, It is the particle's serial number. It is the index of the nearest particle. N It is the total number of particles. It is a fundamental particle The field function, and , It is a fundamental particle The derivative of the field function, It is particle density. It is the particle mass. It is a fundamental particle The radius of the smooth kernel within the range of influence. It is a smooth kernel function. The gradient of the smooth kernel function.

5. The method according to claim 4, characterized in that, The updated smoothing kernel function is expressed by the following formula: ， in, , representing particles With particles The distance, of which Let be the scaling factor of the kernel function space dimension, which is in two-dimensional space. .

6. The method according to claim 5, characterized in that, The preset particle change parameters include density change, internal force change, and stress change.

7. The method according to claim 6, characterized in that, Density change is expressed by the following formula: ， Changes in internal forces are expressed by the following formula: ， Stress changes are expressed by the following formula: ， in, and In Cartesian coordinates, x, y and z value, Represented as the Cauchy stress tensor, External forces acting on fundamental particles For the Dirac function, Artificial viscosity, For artificial stress, P It is isotropic pressure, and , It is a deviatoric stress. This represents the Hugoniot curve function. It is the Grüneisen parameter. , It is the density of the initial particles. It is the current particle density. , The strain rate tensor is defined as: , and It is the torsion rate tensor, and .

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1 to 7.

9. A non-transitory computer-readable storage medium storing computer instructions, characterized in that, The computer instructions are used to cause the computer to perform the method as described in any one of claims 1 to 7.

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