Method for establishing two-dimensional micro-pore discrete element model of rock-soil mass

Abstract

The present application relates to the technical field of structure reconstruction, and particularly relates to a two-dimensional meso-pore discrete element model establishing method of rock-soil mass. The method comprises the following steps: step 1, obtaining pore characteristic parameters of the rock-soil mass through a mercury injection experiment; step 2, obtaining macro-mechanical parameters of the rock-soil mass through a laboratory triaxial compression test; step 3, calibrating particle size distribution and contact stiffness of the rock-soil mass by using a two-dimensional pore network generation algorithm of the discrete element, and gradually adjusting the particle size distribution and the particle contact stiffness so that the two are consistent; step 4, calibrating parameters of the discrete element rock-soil mass sample to obtain a discrete element reconstructed rock-soil mass which is consistent with the pore characteristics and mechanical characteristics of the rock-soil mass; and step 5, equivalent additional stress to a concentrated force which is applied on the corresponding particle through applied force. The present application guarantees the efficiency of the model establishment, and the construction of the pore network discrete element model can solve the deficiency that the existing model is difficult to consider the meso-structure characteristics of the rock-soil mass, and is beneficial to the research on the influence of the change of the substances in the meso-pore of the rock-soil mass.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of structure reconstruction, in particular to a method for establishing a two-dimensional micro-pore discrete element model of a rock-soil body. BACKGROUND

[0002] In the prior art, numerical simulation methods for rock-soil body materials mainly adopt continuous medium methods (finite element, finite difference) and discontinuous medium methods (discrete element method). Due to fast calculation speed and easy deformation monitoring, the continuous medium method has a wide application in the field of rock-soil engineering.

[0003] However, since the finite element method and the finite element method are based on the continuous medium mechanics method, they are suitable for engineering scale deformation and stress calculation, and cannot reflect the cracking process of the rock-soil body, nor can they reflect the change of the micro-features thereof.

[0004] Therefore, the discrete element method is often used when studying the cracking and failure of rock-soil body samples. The existing discrete element method commonly uses software such as UEDEC, 3DEC, PFC2D and PFC3D. Among them, the general discrete element method program UEDEC is more suitable for simulating the influence of joints on rock mass. Compared with the particle flow discrete element software PFC, the discrete degree is not high, and it is not possible to carry out more micro-pore structure simulation research.

[0005] The pore structure has a great influence on the macroscopic properties of the rock-soil body, for example, the water migration in the rock-soil body, the freeze-thaw failure, and the salt heaving process of saline soil are all affected by the pore structure characteristics. Therefore, the reconstruction of the micro-pore network of the rock-soil body in the simulation process is extremely important for further studying the rock-soil body failure process caused by the change of the pore material. The current pore network reconstruction process of the rock-soil body mainly obtains the pore geometric characteristics through ct scanning and divides the grid based on this to carry out continuous medium operation.

[0006] However, due to the large number of pores, small size, irregular geometry and other reasons, the grid around the pores needs to be encrypted, and finally the grid size difference is large, the number is large, and the calculation is prone to non-convergence phenomenon, which cannot simulate the cracking and failure of the rock-soil body caused by the change of the pore material, and restricts the research on the macroscopic failure process caused by the change of the micro-structure of the rock-soil body. Therefore, a discrete element pore network model establishing method with strong calculability and higher accuracy is needed. SUMMARY

[0007] In view of the above problems, the present application provides a method for establishing a two-dimensional micro-pore discrete element model of a rock-soil body. The rock-soil body discrete element micro-pore model constructed by the method is different from the grid division method by ct scanning in the prior art, and does not need to divide the grid, avoiding the defects of too many grids caused by grid division, non-convergence of model calculation and the like.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] A method for establishing a two-dimensional discrete element model of micropores in soil and rock masses includes:

[0010] Step 1: Prepare the rock and soil mass and obtain the pore characteristic parameters of the rock and soil mass through mercury intrusion porosimetry. The pore characteristic parameters include the porosity and pore distribution characteristic curve of the rock and soil mass.

[0011] Step 2: Obtain the macroscopic mechanical parameters of the soil and rock mass through indoor triaxial compression tests. The macroscopic mechanical parameters include the stress-strain parameters and failure mode parameters of the soil and rock mass.

[0012] Step 3: The discrete element method for generating two-dimensional pore networks is used to calibrate the particle size distribution and contact stiffness of the soil and rock mass, and the particle size distribution and particle contact stiffness are gradually adjusted to make them consistent.

[0013] Step 4: Based on the particle size distribution obtained in Step 3 and the macroscopic mechanical parameters of the soil and rock mass obtained in Step 2, the discrete element soil and rock mass samples are calibrated to obtain a two-dimensional discrete element model of the soil and rock mass with micropore characteristics that conforms to the pore characteristics and mechanical characteristics of the soil and rock mass.

[0014] Preferably, step 3 includes:

[0015] Step 3.1: Open the PFC software and use the Ball distribute command to generate a two-dimensional discrete element model of the soil and rock mass size in Step 1. The two-dimensional discrete element model of the soil and rock mass is composed of soil particles. The two-dimensional discrete element model of the soil and rock mass is further given a linear model, and a contact based on soil particles is generated at the same time.

[0016] Step 3.2: Traverse all contacts, find the contact path with the smallest included angle and form a closed figure, to obtain the smallest closed figure formed by the soil particles;

[0017] Step 3.3: In the PFC software, based on the ball and contact that form the smallest closed shape, the center of the ball is used as the vertices of the geometric shape, and the contact is used as the edge of the geometric shape. The geometry shape corresponding to the smallest closed shape is generated by the geometry generate command of the PFC software.

[0018] Step 3.4: In the PFC software, the geometric area of ​​the smallest closed shape is obtained by using the geometry.poly.area command, and the area of ​​the corresponding sector of the particles in the smallest closed shape is subtracted to obtain the area of ​​the pore part in the smallest closed shape.

[0019] Step 3.5: Obtain the geometric center point of the smallest closed shape using the geometry.pos command. At this position, based on the principle of area equivalence, the area of ​​the pore part is equivalent to a circular pore. Then, the geometry corresponding to the pore in the closed shape is generated again using the geometrygenerate command of the PFC software.

[0020] Step 3.6: Compare the equivalent pore characteristic parameters with the pore characteristic parameters of the soil and rock mass in Step 1, and gradually adjust the particle size distribution and particle contact stiffness to make them consistent.

[0021] Preferably, step 4 specifically includes:

[0022] Step 4.1: Based on the particle size distribution and contact stiffness obtained in Step 3, a discrete element soil sample is generated using the linear model in PFC software. The consistency of the equivalent pore characteristic parameters of the discrete element soil sample with the pore characteristic parameters of the soil sample in Step 1 is confirmed.

[0023] Step 4.2: In the PFC software, the particle contact of the discrete element soil sample is assigned a linear pbond model. The parameters of the discrete element soil sample are tested and then the mechanical parameters of the discrete element soil sample are determined. Finally, a two-dimensional discrete element model of the micropores of the soil sample is obtained.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] (1) The discrete element micropore model of soil and rock constructed in this invention is different from the CT scanning meshing method in the prior art. It does not require meshing, thus avoiding defects such as excessive number of meshes and non-convergence of model calculation caused by meshing.

[0026] (2) Compared with the continuous medium calculation model, the discrete element model adopted in this invention can reflect the changes in microscopic pore characteristics caused by changes in the material in the pores and the cracking and propagation law of the rock and soil.

[0027] (3) The highly discrete model of the particle flow discrete element PFC of the present invention, compared with the block structure of UDEC (Universal Discrete Element Model), can better reflect the particle nature of the soil and rock and reflect the influence of micropores on macroscopic mechanical properties.

[0028] (4) The discrete element microporous network generation algorithm proposed in this invention uses the minimum closed graph retrieval algorithm to generate the corresponding geometrypoly, and uses geometric calculation to convert the gaps between particles in PFC software (particle flow discrete element software) into circular pores through geometric size equivalence, which solves the problem of difficulty in quantifying the gaps between particles. It has good correspondence with the particles of rock and soil in microstructure. Attached Figure Description

[0029] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0030] In the attached diagram:

[0031] Figure 1 This is a flowchart of the method of the present invention;

[0032] Figure 2(a) shows the relationship between the cumulative mercury ingress and the pore size obtained from the mercury intrusion porosimetry experiment;

[0033] Figure 2(b) shows the relationship between the mercury injection increment and the pore size obtained from the mercury intrusion porosimetry experiment;

[0034] Figure 3 An algorithm for generating pore networks in soil and rock masses;

[0035] Figure 4 It is a two-dimensional discrete element model of soil and rock.

[0036] Figure 5 When generating a linear model, the PFC software generates a model based on the overlap of soil particles and the contact between soil particles.

[0037] Figure 6 for Figure 5 Enlarged image;

[0038] Figure 7 To obtain all contacts connected to B2 using the ball.contactmap command;

[0039] Figure 8 To generate the geometry graphic corresponding to the closed shape using the geometry generate command in PFC software;

[0040] Figure 9 Generate geometry corresponding to gaps in closed graphics for the geometry generate command in PFC software;

[0041] Figure 10 This relates the equivalent pore size to the cumulative equivalent pore area.

[0042] Figure 11 The `appliedforce` command is used to apply concentrated force to the corresponding particles.

[0043] Figure 12 The damage evolution of samples after different freeze-thaw cycles is shown. Detailed Implementation

[0044] The following combination Figures 1-12The preferred embodiments of the present invention will be described herein. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0045] Example:

[0046] like Figure 1 A method for establishing a two-dimensional discrete element model of micropores in soil and rock masses, comprising:

[0047] Step 1: Obtain the pore characteristic parameters of the soil and rock mass through mercury intrusion porosimetry (MIP) experiments. These parameters include the porosity and pore distribution characteristic curves of the soil and rock mass. Specifically, this includes:

[0048] Step 1.1: Soil and rock sample preparation. Take out the soil and rock sample for which the porosity parameters need to be measured (e.g., loess, porous rock, a standard cylindrical sample with a diameter of 39.1 mm and a height of 80 mm), and cut it into pieces with a volume of approximately 1 cm³. 3 The cubic samples were then air-dried.

[0049] Step 1.2: Low-pressure operation. Open the AutoPore IV 9500 software interface, turn on the nitrogen cylinder switch, and turn on the mercury porosimeter; weigh the loess sample from Step 1.1, transfer the loess sample into the dilatometer, seal it, and weigh it; place the weighed dilatometer into the low-pressure chamber; select low-pressure test in the software interface, fill in the relevant information, and perform the low-pressure test.

[0050] Step 1.3: High-pressure operation. After the low-pressure test, place the mercury-injected dilatometer into the high-pressure chamber to prepare for the high-pressure test; select high-pressure test in the software interface, fill in the relevant information, and conduct the high-pressure test; after the high-pressure test is completed, remove the dilatometer from the high-pressure chamber; open the dilatometer, pour out the waste mercury and waste sample, clean the dilatometer, and put it back in its original position; turn off the mercury intrusion porosimeter and turn off the nitrogen cylinder switch.

[0051] Step 1.4: Export data using AutoPore IV 9500 software. Export instrument parameters, sample information, and the porosity and pore distribution characteristic curve parameters of the soil and rock mass obtained from the test. As shown in Figure 2, Figure 2(a) shows the relationship curve between cumulative mercury ingress and pore size, and Figure 2(b) shows the relationship curve between the incremental mercury ingress and pore size. Both of these are pore distribution characteristic curves, from which the pore distribution characteristic curve parameters can be obtained.

[0052] Step 2: Obtain the macroscopic mechanical parameters of the soil and rock mass through indoor triaxial compression tests. These macroscopic mechanical parameters include the stress-strain parameters and failure mode parameters of the soil and rock mass. These include:

[0053] Step 2.1: Sample Installation. Open the pore pressure valve and measuring tube valve to fill the pressure chamber base with water and vent the air, then close the valves. Next, open the drain valve to fill the sample cap with water and vent the air, then close the valve. Place the permeable stone, filter paper, sample wrapped in a rubber membrane, filter paper, permeable stone, and sample cap on the base in sequence. Before wrapping the sample in the rubber membrane, attach 7-9 strips of moistened filter paper around it. Secure the rubber membrane to the pressure chamber base and sample cap with rubber rings. Install the pressure chamber cover and fill it with water.

[0054] Step 2.2: Drainage Consolidation. Open the NSIF data acquisition and processing software that comes with the triaxial testing instrument computer, enter the “Acquisition → Triaxial Test” interface, and enter the test number, soil sample number, test method (CD), specimen height (8.00cm), specimen diameter (3.91cm), loading level (1), axial strain (15%) and steel ring coefficient in the “Test Parameters” column. Enter the confining pressure (100, 200, 300kPa) in the “Pressure Control” column.

[0055] Click "Start Test". The computer will prompt "Please apply confining pressure". On the control panel, operate "Preset → Pressurize → Preset". Then manually assist in pressurizing to 80%–90% of the preset value, engage the locking pin, and press the "Start" button. Once the confining pressure reading stabilizes at the preset value, click "Start Test" again. The computer will prompt "Start draining, please open the drain valve". Open the drain valve. Once the consolidation degree reaches 95% or higher, click "Start Test" again. The computer will prompt "Consolidation complete, please close the drain valve". Close the drain valve.

[0056] Step 2.3: Sample Shearing. In neutral, the pressure chamber top rod contacts the steel ring, then select the gear and engage the gear. Enter the shearing rate (0.012% / min) in the "Main Control" section, open the drain valve, and click "Start Shearing".

[0057] Step 2.4: After the specimen reaches failure, the computer exports the stress-strain curve of the specimen, calculates the elastic modulus of the specimen (stress-strain parameter), and plots the stress Mohr circle to obtain the cohesion and internal friction angle of the specimen (failure mode parameter).

[0058] Step 3: Soil and rock pore network generation algorithm as follows Figure 3 As shown, a discrete element method (DEM) two-dimensional pore network generation algorithm is used to calibrate the particle size distribution and contact stiffness of soil and rock masses, and the particle size distribution and particle contact stiffness are gradually adjusted to achieve consistency. Specifically, this includes:

[0059] Step 3.1: Open the PFC software and use the Ball distribute command to generate a two-dimensional discrete element model of the soil and rock mass with the sample size from Step 1.1 (e.g., ...). Figure 4As shown, the two-dimensional discrete element model of soil and rock is composed of soil particles. A linear model is further assigned to this model. During the generation of the linear model, the PFC software generates a model based on the overlap of soil particles and their contact information. Figure 5 As shown, zoom in on it, as... Figure 6 The green portion is shown in the diagram; therefore, the two-dimensional discrete element model of soil and rock mass consists of generated particles and a linear property. (The sample is a standard cylinder with a diameter of 39.1 mm and a height of 80 mm. The initial particle size radius is set to 0.01 times the sample radius to control the total number of particles. During subsequent adjustments, this is used as a reference to set the particle size fluctuation range and determine the particle size parameters).

[0060] Step 3.2: Using the `contact.list` command in the PFC software, traverse all contacts from Step 3.1 (a `contact` is a computational element in the PFC software), find the contact path with the smallest included angle and form a closed shape, thus obtaining the smallest closed shape enclosed by the soil particles. The specific algorithm for Step 3.2 is as follows:

[0061] Step 3.2.1: Use the `contact.list` command to iterate through all contacts in the discrete element sample, and use `contact.extra` to mark whether a closed shape has been generated for each contact (1 represents generated, 0 represents not generated, and the initial state is set to 0). Determine whether the current contact has generated a closed shape. If the contact has generated the corresponding closed shape, exit the loop. If the corresponding closed shape has not been generated, set this contact as the initial contact, and perform the following operations on each iterated contact.

[0062] Step 3.2.2: Use the contact.end command to find the two particles connected to the initial contact (each contact corresponds to only two particles) and set them as B1 and B2, and set the vector as the initial vector.

[0063] Step 3.2.3: Use the ball.contactmap command to obtain all contacts connected to B2, such as... Figure 7 As shown, these are named C21, C22, C23, and C24 respectively. The angles between the contact vectors and the initial vectors B1 and B2 are calculated based on their positional relationships, and the contact with the smallest angle perpendicular to the initial vector and extending outwards from the plane is found. (The text continues with further details.) Figure 7 As shown, the selected contact is C24.

[0064] Step 3.2.4: Obtain the other particle connected to the contact (C24 in this example) using the contact.end command, such as... Figure 7The corresponding value is B3. It is then determined whether B3 and the initial B1 are the same particle. If they are the same particle, it indicates that they form the smallest closed shape. The initial contact C1 is marked using `contact.extra`, and a geometry is generated using the `geometry generate` command for subsequent calculation of the equivalent pore area.

[0065] Step 3.3: In the PFC software, based on the ball and contact that form the smallest closed shape, using the center of the ball as the vertices of the geometric shape and the contact as the edges, the geometry shape corresponding to the smallest closed shape is generated using the geometry generate command in the PFC software (e.g., ...). Figure 8 As shown), geometry graphics are used to store information such as the position and area of ​​a graphic.

[0066] Step 3.4: In the PFC software, the geometric area of ​​the smallest closed shape is obtained by using the geometry.poly.area command, and the area of ​​the corresponding sector of the particles in the closed shape is subtracted to obtain the area of ​​the pore part in the smallest closed shape.

[0067] Step 3.5: As Figure 9 As shown, the geometric center point of the smallest closed shape is obtained by using the geometry.pos command. At this position, the area of ​​the pore part is equivalent to a circular pore based on the principle of area equivalence. Then, the geometry corresponding to the pore in the smallest closed shape is generated again by using the geometry generate command of PFC software.

[0068] The specific area relationship formula is: S p =S abcd -S a -S b -S c -S d

[0069] In the formula: S p S is the equivalent pore area; abcd S is the area of ​​the polygon formed by connecting the centers of all particles; a S b S c S d These represent the areas of the sectors corresponding to particles a, b, c, and d within the closed figure, respectively.

[0070] Step 3.6: As Figure 10 The equivalent pore characteristic parameters generated in step 3.5 are compared with the pore characteristic parameters of the soil and rock mass in step 1, and the particle size distribution and particle contact stiffness are gradually adjusted to make them consistent.

[0071] Step 4: Based on the particle size distribution obtained in Step 3 and the macroscopic mechanical parameters of the soil and rock mass obtained in Step 2, discrete element method (PIF) soil and rock mass samples are generated using PFC. The parameters of the PIF soil and rock mass samples are calibrated to obtain a two-dimensional discrete element model of the soil and rock mass with microscopic pore size that conforms to the pore and mechanical characteristics of the soil and rock mass. This includes:

[0072] Step 4.1: Based on the particle size distribution and contact stiffness obtained in Step 3, a discrete element soil sample is generated using the linear model in PFC software. The consistency of the equivalent pore characteristic parameters of the discrete element soil sample with the pore characteristic parameters of the soil sample in Step 1 is confirmed.

[0073] If they match, the particle size parameters can be determined. Otherwise, return to step 3.1, change the particle size distribution, and generate a new sample (using a trial-and-error method).

[0074] Step 4.2: In the PFC software, the particle contact of the discrete element soil sample is assigned a linearpbond model. The parameters of the discrete element soil sample are tested and then the mechanical parameters of the discrete element soil sample, such as elastic modulus, internal friction angle and cohesion, are determined. Finally, a two-dimensional discrete element model of the micropores of the soil sample is obtained.

[0075] The determination process employs a trial-and-error method. If the mechanical parameters of the discrete element soil sample are consistent with those of the real loess sample in step 2, the calibration of the discrete element soil sample's mechanical parameters is complete. If they are inconsistent, a triaxial compression process simulation is performed to adjust the microscopic parameters of the discrete element soil sample until its mechanical properties are consistent with those of real loess, i.e., the stress-strain curve of the discrete element soil sample is consistent with the curve obtained from the experiment.

[0076] After calibration, the mechanical parameters of the discrete element soil sample in this embodiment are as follows: Table 1:

[0077] Table 1 Mechanical parameters of discrete element rock and soil samples

[0078]

[0079] Step 5: Calculate the additional stress generated during this process based on the formula for additional pore stress caused by the corresponding material changes. Then, use the `ball.appliedforce` command to convert the additional stress into a concentrated force applied to the corresponding particles. Specifically, this includes:

[0080] Step 5.1: Calculate the additional stress in the pore network of the soil and rock mass caused by material changes based on the micromechanical formulas corresponding to the research content. The elastic pore ice pressure formula is used here:

[0081]

[0082] In the formula: E i ν i These are the elastic modulus and Poisson's ratio of porous ice, respectively; E m ν m , respectively, represent the elastic modulus and Poisson's ratio of the soil matrix; n is the porosity of the soil.

[0083] Step 5.2: Through vector calculation, the stress on the uniformly distributed pore network is equivalent to a concentrated force, and then applied to the corresponding particles using the appliedforce command. For example... Figure 11 As shown, taking particle d as an example, its pore additional stress equivalent concentrated force is calculated according to the following formula:

[0084] fpd=fp·θ d ·r d

[0085] Where fpd is the equivalent concentrated force corresponding to particle d; fp is the additional stress caused by the change in material; θ d The angle r corresponds to the region where the particle experiences additional stress. d Let d be the radius of the particle;

[0086] Step 5.3: Simulate 5, 10, 15, and 20 freeze-thaw cycles on the discrete element sample, respectively. The failure evolution of the sample after different freeze-thaw cycles is shown in [the table below]. Figure 9 It can be seen that the freeze-thaw process involves the breakdown of the cementation between soil particles.

[0087] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for establishing a two-dimensional discrete element model of micropores in soil and rock, characterized in that: include: Step 1: Prepare the rock and soil mass and obtain the pore characteristic parameters of the rock and soil mass through mercury intrusion porosimetry. The pore characteristic parameters include the porosity and pore distribution characteristic curve of the rock and soil mass. Step 2: Obtain the macroscopic mechanical parameters of the soil and rock mass through indoor triaxial compression tests. The macroscopic mechanical parameters include the stress-strain parameters and failure mode parameters of the soil and rock mass. Step 3: The discrete element method for generating two-dimensional pore networks is used to calibrate the particle size distribution and contact stiffness of the soil and rock mass, and the particle size distribution and particle contact stiffness are gradually adjusted to make them consistent. Step 3.1: Open the PFC software and use the Ball distribute command to generate a two-dimensional discrete element model of the soil and rock mass size in Step 1. The two-dimensional discrete element model of the soil and rock mass is composed of soil particles. The two-dimensional discrete element model of the soil and rock mass is further given a linear model, and a contact based on soil particles is generated at the same time. Step 3.2: Traverse all contacts, find the contact path with the smallest included angle and form a closed figure, to obtain the smallest closed figure formed by the soil particles; Step 3.3: In the PFC software, based on the ball and contact that form the smallest closed shape, the center of the ball is used as the vertices of the geometric shape, and the contact is used as the edge of the geometric shape. The geometry shape corresponding to the smallest closed shape is generated by the geometry generate command of the PFC software. Step 3.4: In the PFC software, the geometric area of ​​the smallest closed shape is obtained by using the geometry.poly.area command, and the area of ​​the corresponding sector of the particles in the smallest closed shape is subtracted to obtain the area of ​​the pore part in the smallest closed shape. Step 3.5: Obtain the geometric center point of the smallest closed shape using the geometry.pos command. At this position, based on the principle of area equivalence, the area of ​​the pore part is equivalent to a circular pore. Then, the geometry corresponding to the pore in the closed shape is generated again using the geometry generate command of PFC software. Step 3.6: Compare the equivalent pore characteristic parameters with the pore characteristic parameters of the soil and rock mass in Step 1, and gradually adjust the particle size distribution and particle contact stiffness to make them consistent. Step 4: Based on the particle size distribution obtained in Step 3 and the macroscopic mechanical parameters of the soil and rock mass obtained in Step 2, the discrete element soil and rock mass samples are calibrated to obtain a two-dimensional discrete element model of the soil and rock mass with micropore characteristics that conforms to the pore characteristics and mechanical characteristics of the soil and rock mass.

2. The method for establishing a two-dimensional discrete element model of micropores in rock and soil according to claim 1, characterized in that: Step 4 is as follows: Step 4.1: Based on the particle size distribution and contact stiffness obtained in Step 3, a discrete element soil sample is generated using the linear model in PFC software. The consistency of the equivalent pore characteristic parameters of the discrete element soil sample with the pore characteristic parameters of the soil sample in Step 1 is confirmed. Step 4.2: In the PFC software, the particle contact of the discrete element soil sample is assigned a linear pbond model. The parameters of the discrete element soil sample are tested and then the mechanical parameters of the discrete element soil sample are determined. Finally, a two-dimensional discrete element model of the micropores of the soil sample is obtained.

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