A numerical simulation method and device for simulating rock and soil seepage force based on discrete element particle flow

Abstract

The present invention discloses a numerical simulation method and device for simulating rock and soil seepage force based on discrete element particle flow. The present invention uses the discrete element method to establish a rock and soil model, and adopts particle assembly rock and soil to completely and realistically restore the actual state of the rock and soil skeleton compared with finite element and boundary element methods. On this basis, the present invention uses the fluid-solid coupling algorithm to generate a seepage network of fluid flow in the pore throat of the rock and soil model to simulate the seepage process of the fluid in the rock and soil pore throat, and applies the effect of the seepage force to the rock and soil particles in the form of volume force, thereby finally realizing the effect of the seepage force on the rock and soil in the fluid seepage process based on discrete element particle flow simulation, thereby providing a reliable numerical simulation method for the next step of analyzing engineering mechanics problems.

Description

Technical Field

[0001] The present invention relates to the field of geotechnical engineering, and in particular to a numerical simulation method and device for simulating geotechnical seepage force based on discrete element particle flow. Background Art

[0002] Seepage force, also known as permeability, refers to the drag force exerted on soil particles by a unit volume of fluid flowing through the pore throats of rock and soil. Seepage force is a key research topic in geotechnical engineering mechanics. This force acts directly on the rock and soil skeleton, altering the effective stress state of the skeleton. Seepage force is a significant factor influencing engineering challenges such as slope instability, tunnel face failure, dam collapse, and the propagation trajectory of hydraulic fractures. Studying the magnitude of seepage force and simulating its effects on the rock or soil skeleton are crucial for resolving engineering challenges and optimizing construction plans.

[0003] Continuum numerical simulation methods such as boundary elements, finite elements, and finite differences have very significant limitations and shortcomings when simulating and analyzing large deformation failure and gradual failure in geotechnical engineering. The discrete element particle flow method uses particles to assemble into rocks, which can restore the deformation characteristics and mechanical response of geotechnical materials to the greatest extent. Therefore, it has gradually become a research hotspot in numerical simulation methods in recent years. However, there are few reports on how to use the discrete element particle flow method to simulate the effect of seepage force on geotechnical particles during fluid seepage. The simulation of seepage force is still one of the difficult problems that need to be overcome in the discrete element particle flow numerical simulation method. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a numerical simulation method and device for simulating rock and soil seepage force based on discrete element particle flow. The present invention can provide geotechnical engineers with reliable numerical simulation and provide guidance for actual engineering.

[0005] The technical solution adopted in the present invention is as follows:

[0006] A numerical simulation method for simulating rock and soil seepage force based on discrete element particle flow includes the following steps:

[0007] Establishing a numerical rock sample model: setting the particle size using a power function distribution particle size gradation, and then establishing the numerical rock sample model in the PFC discrete element software according to actual needs;

[0008] Calibration of the mesoscopic parameters of the numerical rock sample model: The LinearParallelBond model is used to cement the established numerical rock sample model into a sample. The mesoscopic parameters of the numerical rock sample model are calibrated using the mechanical parameters of the actual rock sample. The seepage control parameters of the actual rock sample are used to calibrate the fluid domain channel opening m of the fluid-solid coupling algorithm.

[0009] Generation of seepage network and setting of boundary conditions in numerical rock sample model: The fluid-solid coupling algorithm of discrete element particle flow method is used to generate the seepage network in the numerical rock sample model with mesoscopic parameter calibration, and the injection and outflow conditions of the fluid are set in the numerical rock sample model;

[0010] Simulation of fluid seepage process and application of seepage force: Based on boundary conditions, a numerical rock sample model with a seepage network is used to simulate the unsteady-state seepage process of the fluid. At the same time, the seepage force during the fluid seepage process is applied to the particles of the numerical rock sample model to simulate the effect of seepage force on rock and soil deformation and failure;

[0011] Monitoring of seepage force and numerical simulation of engineering problems: A script file written using the Fish function is used to monitor the magnitude of the seepage force acting on the numerical rock sample model in real time. When the seepage force is stable, numerical simulation of actual engineering problems is carried out.

[0012] Preferably, the suspended particles in the established numerical rock sample model are processed so that the seepage network generated by the numerical rock sample model avoids the generation of pores;

[0013] The process of processing suspended particles in the established numerical rock sample model includes:

[0014] The ball.contactmap function is used to write a script file to identify the contact number of all particles. Particles with a contact number ≤ 2 are identified as suspended particles. Then, the ball.radius function is used to increase the particle size of all suspended particles by 1 to 1.5 times to ensure that the number of suspended particles is ≤ 5.

[0015] Preferably, when calibrating the mesoscopic parameters of the numerical rock sample model using the mechanical parameters of the actual rock sample, the mesoscopic parameters of the numerical rock sample model are calibrated using the numerical simulation experiments of uniaxial tension and uniaxial compression of rock using the PFC software. The mesoscopic parameter calibration of the numerical rock sample model is completed by continuously adjusting the values ​​of the mesoscopic parameters until the error between the mechanical parameters of the rock sample measured by the numerical simulation experiments of uniaxial tension and uniaxial compression of rock using the PFC software and the mechanical parameters of the actual rock sample is less than a preset value.

[0016] The microscopic parameters of the numerical rock sample model include tensile strength pb_ten, cohesion pb_coh, internal friction coefficient pb_fa, effective modulus pb_emod and stiffness ratio pb_kratio. The mechanical parameters of the rock sample include Poisson's ratio ν, Young's modulus E, tensile strength σ t and compressive strength σ f .

[0017] Preferably, when calibrating the fluid domain channel opening m of the fluid-solid coupling algorithm using the seepage control parameters of the actual rock sample, the Darcy seepage numerical simulation experiment of the PFC software is used to calibrate the fluid domain channel opening m of the fluid-solid coupling algorithm under steady-state seepage flow conditions; during the calibration process, the value of m is adjusted until the error between the permeability k of the numerical rock sample model measured by the Darcy seepage numerical simulation experiment and the seepage control parameter of the actual rock sample is less than a preset value, and the calibration is completed.

[0018] Preferably, the seepage network is generated in the numerical rock sample model using the dom function file of the PFC software, and the injection condition is set to a constant pressure P w Displacement, outflow condition is 0 MPa fixed water pressure.

[0019] Preferably, when simulating the fluid seepage process and applying the seepage force:

[0020] The flow mode of fluid in the seepage network is circular tube Poiseuille flow, which satisfies the following relationship:

[0021]

[0022] Where Q is the flow rate of the fluid domain, m is the fluid domain channel opening, Δp is the pressure difference between two adjacent fluid domains, L is the length of the flow channel, and μ is the viscosity of the fluid;

[0023] The magnitude of the seepage force on particles during fluid seepage is as follows:

[0024]

[0025] Among them, F seepage force is the seepage force, P is the pore pressure of the fluid domain, n i is the normal vector of the line segment connecting two adjacent contact points of the particle, and s is the length of the line segment between two adjacent contact points of the particle;

[0026] Use the ball.force.app function to apply F to each loop time step. seepageforce The particles applied to the numerical rock sample model simulate the effect of seepage force on rock and soil deformation and failure.

[0027] Preferably, the process of using the script file written by the Fish function to monitor the magnitude of the seepage force acting on the numerical rock sample model in real time includes:

[0028] Firstly, an area is selected in the numerical rock sample model as the monitoring area of ​​seepage force;

[0029] Then, the ball.list function is used to traverse all particles in the seepage force monitoring area, and the ball.force.app function is used to accumulate the seepage forces exerted by all particles, thereby obtaining the total seepage force F exerted on the particles in the seepage force monitoring area. tot Finally, the history function is used to calculate the total seepage force F in the seepage force monitoring area. tot Conduct real-time monitoring.

[0030] The present invention also provides a numerical simulation device for simulating rock and soil seepage force based on discrete element particle flow, comprising:

[0031] Numerical simulation module for:

[0032] Establishing a numerical rock sample model: setting the particle size using a power function distribution particle size gradation, and then establishing the numerical rock sample model in the PFC discrete element software according to actual needs;

[0033] Calibration of the mesoscopic parameters of the numerical rock sample model: The LinearParallelBond model is used to cement the established numerical rock sample model into a sample. The mesoscopic parameters of the numerical rock sample model are calibrated using the mechanical parameters of the actual rock sample. The seepage control parameters of the actual rock sample are used to calibrate the fluid domain channel opening m of the fluid-solid coupling algorithm.

[0034] Generation of seepage network and setting of boundary conditions in numerical rock sample model: The fluid-solid coupling algorithm of discrete element particle flow method is used to generate the seepage network in the numerical rock sample model with mesoscopic parameter calibration, and the injection and outflow conditions of the fluid are set in the numerical rock sample model;

[0035] Simulation of fluid seepage process and application of seepage force: Based on boundary conditions, a numerical rock sample model with a seepage network is used to simulate the unsteady-state seepage process of the fluid. At the same time, the seepage force during the fluid seepage process is applied to the particles of the numerical rock sample model to simulate the effect of seepage force on rock and soil deformation and failure;

[0036] Monitoring of seepage force and numerical simulation of engineering problems: A script file written using the Fish function is used to monitor the magnitude of the seepage force acting on the numerical rock sample model in real time. When the seepage force is stable, numerical simulation of actual engineering problems is carried out.

[0037] The present invention also provides an electronic device, comprising:

[0038] one or more processors;

[0039] a storage device having one or more programs stored thereon;

[0040] When the one or more programs are executed by the one or more processors, the one or more processors implement the numerical simulation method for simulating rock seepage force based on discrete element particle flow as described above in the present invention.

[0041] The present invention also provides a storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the numerical simulation method for simulating rock and soil seepage force based on discrete element particle flow as described above is implemented.

[0042] The present invention has the following beneficial effects:

[0043] The present invention establishes a numerical simulation method for simulating rock and soil seepage force based on discrete element particle flow. This method can accurately simulate the effect of seepage force on the rock and soil skeleton during fluid seepage, thereby providing a reliable numerical simulation method for analyzing rock and soil deformation and damage under the action of seepage force, and for simulating seepage effects in practical engineering problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The present invention is a flow chart of a numerical simulation method for simulating rock and soil seepage force based on discrete element particle flow.

[0045] Figure 2 This is the numerical rock sample model in Example 1 of the present invention.

[0046] Figure 3 This is the pore pressure distribution field of the Darcy seepage experiment of the numerical rock sample model in Example 1 of the present invention.

[0047] Figure 4 This is a distribution diagram of the seepage force field acting on the particles of the numerical rock sample model in Example 1 of the present invention.

[0048] Figure 5 This is the numerical rock sample model in Example 2 of the present invention.

[0049] Figure 6 This is the pore pressure distribution field of the Darcy seepage experiment of the numerical rock sample model in Example 2 of the present invention.

[0050] Figure 7 This is a distribution diagram of the seepage force field acting on the particles of the numerical rock sample model in Example 2 of the present invention. DETAILED DESCRIPTION

[0051] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0052] In order to overcome the problem that the discrete element particle flow method cannot simulate the seepage force of rock and soil, the principle adopted by the present invention is as follows: the fluid will exert drag force and seepage force on the rock and soil particles during the flow in the pore throat of the rock and soil, and the seepage force will affect the deformation and failure characteristics of the rock and soil. The present invention uses the discrete element method to establish a rock and soil model, and uses particles to assemble the rock and soil to completely and realistically restore the actual state of the rock and soil skeleton compared to the finite element, boundary element and other methods. On this basis, the present invention uses the fluid-solid coupling algorithm to generate a seepage network of fluid flow in the pore throat of the rock and soil model to simulate the seepage process of the fluid in the pore throat of the rock and soil, and applies the seepage force to the rock and soil particles in the form of volume force, thereby finally realizing the simulation of the seepage force on the rock and soil during the fluid seepage process based on the discrete element particle flow, thereby providing a reliable numerical simulation method for the next step of analyzing engineering mechanics problems.

[0053] The technical solutions of the present invention are as follows:

[0054] See also Figure 1 The numerical simulation method of soil seepage force based on discrete element particle flow includes the following steps:

[0055] Step 1: Collection of macroscopic parameters of actual rock samples: Collect macroscopic parameters of actual rock samples, including rock mechanics parameters: Poisson's ratio ν, Young's modulus E, tensile strength σ t , compressive strength σ f ; Rock seepage control parameter: rock permeability K.

[0056] Step 2: Establishing a numerical rock sample model: The particle size is set using a power function distribution. Then, a numerical rock sample model is established in the PFC discrete element software based on the actual needs of subsequent engineering simulations. After establishing the numerical rock sample model, the suspended particles are processed to ensure that the seepage network generated in Step 4 below does not produce singularities (i.e., holes). The suspended particle processing process is as follows: First, a script file is written using the ball.contactmap function to determine the number of contacts for all particles. Particles with a contact number ≤ 2 are identified as suspended particles. Then, the ball.radius function is used to increase the particle size of all suspended particles by 1 to 1.5 times to ensure that the number of suspended particles is ≤ 5.

[0057] Step 3: Calibration of the mesoscopic parameters of the numerical rock sample model: Select the LinearParallelBond model to bond the numerical rock sample model, and use the mechanical parameters of the actual rock sample collected in step 1 to calibrate the mesoscopic parameters of the numerical rock sample model. During calibration: Use the PFC software rock uniaxial tension and uniaxial compression numerical simulation experiments to calibrate the mesoscopic parameters of the numerical rock sample model, where the mesoscopic parameters include tensile strength pb_ten, cohesion pb_coh, internal friction coefficient pb_fa, effective modulus pb_emod, and stiffness ratio pb_kratio. By continuously adjusting the values ​​of the five parameters of tensile strength pb_ten, cohesion pb_coh, internal friction coefficient pb_fa, effective modulus pb_emod, and stiffness ratio pb_kratio, until the Poisson's ratio ν, Young's modulus E, and tensile strength σ obtained by the PFC software rock uniaxial tension and uniaxial compression numerical simulation experiments are achieved. t and compressive strength σ f The calibration of the mesoscopic parameters is completed when the error between the mechanical parameter values ​​collected from the actual rock sample in step 1 is less than 2%;

[0058] The fluid domain channel opening m of the fluid-solid coupling algorithm is calibrated using the seepage control parameters of the actual rock sample collected in step 1. During the calibration, the fluid domain channel opening m of the fluid-solid coupling algorithm is calibrated under steady-state seepage flow conditions using the Darcy seepage numerical simulation experiment of the PFC software, thereby ensuring the accuracy of the subsequent seepage force simulation; during the calibration process, the value of m is adjusted until the permeability k of the numerical rock sample model measured by the Darcy seepage numerical simulation experiment and the seepage control parameters of the actual rock sample collected in step 1 have an error of less than 1%, and the calibration of the fluid domain channel opening m is completed.

[0059] Step 4: Generate the seepage network of the numerical rock sample model and set the boundary conditions: Use the fluid-solid coupling algorithm of the discrete element particle flow method to generate the seepage network in the numerical rock sample model, and set the injection and outflow conditions of the fluid in the numerical rock sample model. Specifically, in this step, use the dom function file of the PFC software to generate the seepage network in the numerical rock sample model, and set the injection condition to a constant pressure P. w Displacement, outflow condition is 0 MPa fixed water pressure.

[0060] Step 5: Simulate the fluid seepage process and apply seepage force: Based on the boundary conditions, the numerical rock sample model with the seepage network set in Step 4 is used to simulate the unsteady seepage process of the fluid. At the same time, the seepage force during the fluid seepage process is applied to the particles of the numerical rock sample model to simulate the effect of the seepage force on the deformation and damage of the rock and soil. Specifically, the flow mode of the fluid in the seepage network is circular tube Poiseuille flow, which satisfies the following relationship:

[0061]

[0062] Where Q is the flow rate of the fluid domain, m is the fluid domain channel opening, Δp is the pressure difference between two adjacent fluid domains, L is the length of the flow channel, and μ is the viscosity of the fluid.

[0063] The magnitude of the seepage force on particles during fluid seepage is as follows:

[0064]

[0065] Among them, F seepage force is the seepage force, P is the pore pressure of the fluid domain, n i is the normal vector of the line segment connecting two adjacent contact points of the particle, and s is the length of the line segment between two adjacent contact points of the particle;

[0066] Use the ball.force.app function to apply F to each loop time step. seepageforce The particles applied to the numerical rock sample model simulate the effect of seepage force on the deformation and failure of rock and soil.

[0067] Step 6: Monitoring the seepage force and numerical simulation of engineering problems: Use the script file written by the Fish function to monitor the magnitude of the seepage force acting on the numerical rock sample model in real time. When the seepage force is stable, perform numerical simulation of the actual engineering problem. Specifically, the process of using the fish function to write a script file to monitor the seepage force is as follows:

[0068] First, a rectangular area with a length of L1 and a width of W is selected in the numerical rock sample model as the monitoring area of ​​the seepage force. Then, the ball.list function is used to traverse all the particles in the area, and the ball.force.app function is used to accumulate the seepage forces exerted by all the particles to obtain the total seepage force F exerted on the particles in the area. tot Finally, the history function is used to calculate the total seepage force F in the region. tot Conduct real-time monitoring.

[0069] Example 1:

[0070] The numerical simulation method of soil seepage force based on discrete element particle flow in this embodiment includes the following steps:

[0071] Step 1: Create a numerical rock sample model with a length of 12 cm and a width of 5 cm to simulate the seepage force during Darcy seepage. The actual rock sample mechanical parameters are Poisson's ratio ν = 0.25 and Young's modulus E = 4.2 × 10^ 4 MPa, tensile strength σ t =12.5MPa, compressive strength σ f=75MPa; rock seepage control parameters: rock and soil permeability K = 0.02D. The final numerical rock sample model is as follows Figure 2 shown.

[0072] Step 2: Based on the actual rock mechanical parameters collected and combined with the PFC mechanical numerical simulation experiment, the microscopic parameters of the numerical rock sample model are calibrated. When the error between the simulation results and the actual rock mechanical parameters is 1.87%, the calibration results are pb_ten = 10 MPa, pb_coh = 5 MPa, pb_fa = 0.0, and pb_emod = 1.5×10^ 3 MPa, pb_kratio = 2.0. The permeability of the numerical rock sample model was calibrated using the PFC Darcy seepage numerical simulation experiment. When the error was less than 0.5%, the calibration result of the aperture was m = 0.1.

[0073] Step 3: Use the dom function file of the PFC software to generate a seepage network in the numerical rock sample model. Set the fluid domain range of 2 cm on the left side of the numerical rock sample model as the fluid injection end, and the fluid domain range of 2 cm on the right side as the fluid outflow end with a constant pressure of 0 MPa. Then, start fluid displacement at a constant pressure of 1 MPa on the left side to simulate the Darcy seepage experiment process.

[0074] Figure 3 The figure shows the pore pressure distribution field of the Darcy seepage experiment simulation in this embodiment when it is stable. The corresponding distribution diagram of the seepage force field on the particles is shown in FIG. Figure 4 shown.

[0075] Example 2:

[0076] The numerical simulation method of soil seepage force based on discrete element particle flow in this embodiment includes the following steps:

[0077] Step 1: Create a square numerical rock sample model with a length of 0.25 m and a width of 0.25 m to simulate the seepage force field of rock particles around the wellbore during hydraulic fracturing and injection. The actual rock mechanical parameters collected are Poisson's ratio ν = 0.23 and Young's modulus E = 8.7 × 10^ 4 MPa, tensile strength σ t =15.3MPa, compressive strength σ f =95MPa; rock seepage control parameters: rock and soil permeability K = 20mD. The final numerical rock sample model is as follows Figure 5 shown.

[0078] Step 2: Based on the actual rock mechanical parameters collected and combined with the PFC mechanical numerical simulation experiment, the microscopic parameters of the numerical rock sample model are calibrated. When the error between the simulation results and the actual rock mechanical parameters is 1.5%, the calibration results are pb_ten = 12.0 MPa, pb_coh = 30.0 MPa, pb_fa = 45.0, and pb_emod = 3.2 × 10^ 4 MPa, pb_kratio=1.6; the permeability of the numerical rock sample model is calibrated using the PFC Darcy seepage numerical simulation experiment. When the error is less than 0.2%, the calibration result of the aperture is m=0.00078.

[0079] Step 3: Generate a seepage network in the numerical rock sample model using the dom function file of the PFC software. Set the middle wellbore of the numerical rock sample model as the injection end of the fluid, and the four boundaries of the numerical rock sample model as the outflow end of the fluid with a constant pressure of 0 MPa. Then, start the flow in the wellbore at a constant flow rate of 2.5×10^ -3 m 3 / s to carry out fluid displacement, thereby simulating the injection process of hydraulic fracturing.

[0080] Figure 6 The figure shows the pore pressure field distribution diagram around the wellbore after 10,000 cycles of this embodiment. The corresponding seepage force field distribution diagram of the particles is shown in FIG. Figure 7 shown.

Claims

1. A numerical simulation method for simulating rock and soil seepage force based on discrete element particle flow, characterized in that: The process includes the following: Establishing a numerical rock sample model: setting the particle size using a power function distribution particle size gradation, and then establishing the numerical rock sample model in the PFC discrete element software according to actual needs; Calibration of the mesoscopic parameters of the numerical rock sample model: The LinearParallelBond model is used to cement the established numerical rock sample model into a sample. The mesoscopic parameters of the numerical rock sample model are calibrated using the mechanical parameters of the actual rock sample. The seepage control parameters of the actual rock sample are used to calibrate the fluid domain channel opening m of the fluid-solid coupling algorithm. Generation of seepage network and setting of boundary conditions in numerical rock sample model: The fluid-solid coupling algorithm of discrete element particle flow method is used to generate the seepage network in the numerical rock sample model with mesoscopic parameter calibration, and the injection and outflow conditions of the fluid are set in the numerical rock sample model; Simulation of fluid seepage process and application of seepage force: According to the boundary conditions, a numerical rock sample model with a seepage network is used to simulate the unsteady seepage process of the fluid. At the same time, the seepage force during the fluid seepage process is applied to the particles of the numerical rock sample model to simulate the effect of the seepage force on the deformation and damage of the rock and soil. The magnitude of the seepage force on the particles during the fluid seepage process is as follows: in, is the seepage force, P is the pore pressure in the fluid domain, n i is the normal vector of the line segment connecting two adjacent contact points of the particle, s is the length of the line segment between two adjacent contact points of the particles, Δp is the pressure difference between two adjacent fluid domains, m is the channel opening of the fluid domain; Monitoring of seepage force and numerical simulation of engineering problems: A script file written using the Fish function is used to monitor the magnitude of the seepage force acting on the numerical rock sample model in real time. When the seepage force is stable, numerical simulation of actual engineering problems is carried out.

2. The numerical simulation method for simulating rock and soil seepage force based on discrete element particle flow according to claim 1 is characterized in that: The suspended particles in the established numerical rock sample model are processed to avoid the generation of pores in the seepage network generated by the numerical rock sample model; The process of processing suspended particles in the established numerical rock sample model includes: The ball.contactmap function is used to write a script file to identify the contact number of all particles. Particles with a contact number ≤ 2 are identified as suspended particles. Then, the ball.radius function is used to increase the particle size of all suspended particles by 1 to 1.5 times to ensure that the number of suspended particles is ≤ 5.

3. The numerical simulation method for simulating rock and soil seepage force based on discrete element particle flow according to claim 1 is characterized in that: When calibrating the mesoscopic parameters of the numerical rock sample model using the mechanical parameters of the actual rock sample, the mesoscopic parameters of the numerical rock sample model are calibrated using the numerical simulation experiments of uniaxial tension and uniaxial compression of rock using the PFC software. The mesoscopic parameter calibration of the numerical rock sample model is completed by continuously adjusting the values ​​of the mesoscopic parameters until the error between the mechanical parameters of the rock sample measured by the numerical simulation experiments of uniaxial tension and uniaxial compression of rock using the PFC software and the mechanical parameters of the actual rock sample is less than the preset value. The microscopic parameters of the numerical rock sample model include tensile strength, cohesion, internal friction coefficient, effective modulus and stiffness, and the mechanical parameters of the rock sample include Poisson's ratio, Young's modulus, tensile strength and compressive strength.

4. The numerical simulation method for simulating rock and soil seepage force based on discrete element particle flow according to claim 1 is characterized in that: When calibrating the fluid domain channel opening of the fluid-solid coupling algorithm using the seepage control parameters of the actual rock sample, the Darcy seepage numerical simulation experiment of the PFC software is used to calibrate the fluid domain channel opening of the fluid-solid coupling algorithm under steady-state seepage flow conditions; during the calibration process, the value of the fluid domain channel opening is adjusted until the error between the permeability of the numerical rock sample model obtained by the Darcy seepage numerical simulation experiment and the seepage control parameters of the actual rock sample is less than the preset value, and the calibration is completed.

5. The numerical simulation method for simulating rock and soil seepage force based on discrete element particle flow according to claim 1 is characterized in that: The seepage network was generated in the numerical rock sample model using the dom function file of the PFC software. The injection condition was set to constant pressure displacement, and the outflow condition was set to a fixed water pressure of 0 MPa.

6. The numerical simulation method for simulating rock and soil seepage force based on discrete element particle flow according to claim 1 is characterized in that: When simulating the fluid seepage process and applying the seepage force: The flow mode of fluid in the seepage network is circular tube Poiseuille flow, which satisfies the following relationship: in, Q is the flow rate of the fluid domain, m is the fluid channel opening, Δp is the pressure difference between two adjacent fluid domains, L is the length of the flow channel, μ is the viscosity of the fluid; Use the ball.force.app function to apply F seepageforce The particles applied to the numerical rock sample model simulate the effect of seepage force on rock and soil deformation and failure.

7. The numerical simulation method for simulating rock and soil seepage force based on discrete element particle flow according to claim 1 is characterized in that: The process of using the script file written by the Fish function to monitor the magnitude of the seepage force acting on the numerical rock sample model in real time includes: Firstly, an area is selected in the numerical rock sample model as the monitoring area of ​​seepage force; Then, the ball.list function is used to traverse all particles in the seepage force monitoring area, and the ball.force.app function is used to accumulate the seepage forces exerted by all particles to obtain the total seepage force exerted on the particles in the seepage force monitoring area. Finally, the history function is used to monitor the total seepage force in the seepage force monitoring area in real time.

8. A numerical simulation device for simulating rock and soil seepage force based on discrete element particle flow, characterized in that: include: Numerical simulation module for: Establishing a numerical rock sample model: setting the particle size using a power function distribution particle size gradation, and then establishing the numerical rock sample model in the PFC discrete element software according to actual needs; Calibration of the mesoscopic parameters of the numerical rock sample model: The LinearParallelBond model is used to cement the established numerical rock sample model into a sample. The mesoscopic parameters of the numerical rock sample model are calibrated using the mechanical parameters of the actual rock sample. The seepage control parameters of the actual rock sample are used to calibrate the fluid domain channel opening m of the fluid-solid coupling algorithm. Generation of seepage network and setting of boundary conditions in numerical rock sample model: The fluid-solid coupling algorithm of discrete element particle flow method is used to generate the seepage network in the numerical rock sample model with mesoscopic parameter calibration, and the injection and outflow conditions of the fluid are set in the numerical rock sample model; Simulation of fluid seepage process and application of seepage force: According to the boundary conditions, a numerical rock sample model with a seepage network is used to simulate the unsteady seepage process of the fluid. At the same time, the seepage force during the fluid seepage process is applied to the particles of the numerical rock sample model to simulate the effect of the seepage force on the deformation and damage of the rock and soil. The magnitude of the seepage force on the particles during the fluid seepage process is as follows: in, is the seepage force, P is the pore pressure in the fluid domain, n i is the normal vector of the line segment connecting two adjacent contact points of the particle, s is the length of the line segment between two adjacent contact points of the particles, Δp is the pressure difference between two adjacent fluid domains, m is the channel opening of the fluid domain; Monitoring of seepage force and numerical simulation of engineering problems: A script file written using the Fish function is used to monitor the magnitude of the seepage force acting on the numerical rock sample model in real time. When the seepage force is stable, numerical simulation of actual engineering problems is carried out.

9. An electronic device, characterized in that: include: one or more processors; a storage device having one or more programs stored thereon; When the one or more programs are executed by the one or more processors, the one or more processors implement the numerical simulation method for simulating rock seepage force based on discrete element particle flow as described in any one of claims 1 to 7.

10. A storage medium, characterized in that: A computer program is stored thereon, wherein when the computer program is executed by a processor, the numerical simulation method for simulating rock and soil seepage force based on discrete element particle flow as claimed in any one of claims 1 to 7 is implemented.

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