Pulp dispersion simulation method and apparatus based on perturbed flow distribution

Abstract

The application provides a slurry diffusion simulation method and device based on disturbance flow distribution, and belongs to the technical field of rock mass engineering. The method is aimed at a target fractured rock mass to be simulated for slurry distribution. First, statistical parameters of the target fractured rock mass are obtained. Then, a random fracture network model of the target fractured rock mass is established according to the statistical parameters. Next, the random fracture network model is meshed to obtain a meshing result. Then, the permeability of the fractured rock mass before grouting is obtained according to the unified pipe network method and the meshing result. Finally, the grouting situation of the target fractured rock mass is simulated according to a slurry probability diffusion algorithm based on disturbance flow distribution and the permeability of the fractured rock mass before grouting, and a slurry diffusion simulation result of the target fractured rock mass is obtained. In the flow distribution process, a disturbance factor is applied, so that the difference in slurry distribution caused by the interference of uncertain factors can be simulated.

Description

Technical Field

[0001] This application relates to the field of rock mass engineering technology, and in particular to a method and apparatus for simulating slurry diffusion based on disturbance flow distribution. Background Technology

[0002] In recent years, the number of rock mass engineering projects used globally for purposes such as hydropower generation, flood control, transportation, and mining has been gradually increasing. However, geological hazards such as seepage, leakage, and water inrush pose potential threats to the safety of these projects during construction and operation. In particular, under adverse geological conditions such as karst fissures and faults, the destructive power and probability of geological hazards are significantly increased.

[0003] Currently, in rock mass engineering projects such as pumped storage, tunnel engineering, large dams, and underground structures, grouting is used to form a waterproof or water-stopping curtain around the structure, acting as a protective barrier. Therefore, the effectiveness of the grouting directly determines the curtain's seepage prevention performance. However, due to the concealed nature of these projects and numerous uncertainties, such as complex engineering geological conditions (e.g., grout fracturing, confining pressure, and special geological conditions) and varying construction conditions (e.g., construction technology, grouting pressure, water-cement ratio, construction time, and human and economic factors), the flow of grout within the rock mass is highly susceptible to disturbance by these uncertainties, resulting in significant uncertainty in the quality of the curtain formation. Meanwhile, existing simulation methods are usually based on deterministic factors. They obtain the specific distribution of slurry by accurately modeling and determining the slurry flow pattern (such as assuming the slurry flow pattern, flow equation and the coupling effect of soil and rock mass and water). When the slurry flow pattern and the flow equation it follows inside the soil and rock mass change under different geological and construction conditions, the simulation method based on deterministic factors lacks flexibility and the simulation effect is poor.

[0004] Therefore, there is an urgent need for a method that can simulate the distribution of slurry within a rock mass when the flow state is unknown. Summary of the Invention

[0005] This application provides a method and apparatus for simulating slurry diffusion based on disturbance flow distribution, in order to solve the problem of the lack of a method to simulate the distribution of slurry inside rock mass when the flow state is unknown.

[0006] In a first aspect, embodiments of this application provide a slurry diffusion simulation method based on perturbation flow distribution, including:

[0007] Obtain the fracture statistics parameters of the target fractured rock mass; among which, the fracture statistics parameters include fracture length, fracture dip angle, and the distribution function parameters obeyed by the fracture center point;

[0008] Based on fracture statistical parameters, a stochastic fracture network model of the target fractured rock mass is established; the fracture information of the stochastic fracture network model includes fracture coordinates and fracture numbers.

[0009] The random fracture network model is meshed to obtain the meshing results; the meshing results include the mesh cell number, mesh point coordinates, mesh point number, mesh point and edge corresponding to the fracture and their numbers;

[0010] Based on the unified pipeline network method and grid segmentation results, the permeability results of the fractured rock mass before grouting were obtained; among them, the permeability results of the fractured rock mass before grouting include the permeability coefficient, the pressure cloud map of the fractured rock mass, and the flow rate values ​​at various points in the fractured rock mass;

[0011] Based on the grout probability diffusion algorithm based on perturbation flow distribution and the permeability results of the fractured rock mass before grouting, the grouting situation of the target fractured rock mass is simulated, and the grout diffusion simulation results of the target fractured rock mass are obtained.

[0012] Secondly, embodiments of this application provide a slurry diffusion simulation device based on perturbation flow distribution, comprising:

[0013] The fracture statistical parameter acquisition module is used to acquire the fracture statistical parameters of the target fractured rock mass; among which, the fracture statistical parameters include fracture length, fracture dip angle, and the distribution function parameters obeyed by the fracture center point;

[0014] The model building module is used to build a random fracture network model of the target fractured rock mass based on fracture statistical parameters; the fracture information of the random fracture network model includes fracture coordinates and fracture numbers;

[0015] The mesh generation module is used to perform mesh generation on the random fracture network model and obtain the mesh generation results. The mesh generation results include the mesh cell number, mesh point coordinates, mesh point number, mesh points and edges corresponding to the fractures and their numbers.

[0016] The generation module is used to obtain the permeability results of fractured rock mass before grouting based on the unified pipeline network method and grid subdivision results; among which, the permeability results of fractured rock mass before grouting include permeability coefficient, pressure cloud map of fractured rock mass, and flow rate values ​​at various points in fractured rock mass;

[0017] The slurry diffusion simulation module is used to simulate the grouting situation of the target fractured rock mass based on the slurry probability diffusion algorithm based on the permeability of the fractured rock mass before grouting, and to obtain the slurry diffusion simulation results of the target fractured rock mass.

[0018] This application provides a method and apparatus for simulating slurry diffusion based on perturbation flow distribution. For a target fractured rock mass to be simulated for slurry distribution, firstly, the fracture statistical parameters of the target fractured rock mass are obtained. Then, based on the fracture statistical parameters, a random fracture network model of the target fractured rock mass is established. Next, the random fracture network model is meshed to obtain the meshing result. Then, based on the unified pipe network method and the meshing result, the permeability result of the fractured rock mass before grouting is obtained. Finally, based on the slurry probabilistic diffusion algorithm based on perturbation flow distribution and the permeability result of the fractured rock mass before grouting, the grouting situation of the fracture network in the target fractured rock mass is simulated to obtain the slurry diffusion simulation result of the target fractured rock mass. Thus, a method is provided that can simulate the distribution of slurry within a rock mass under conditions of unknown flow state. Because an interference factor is applied during the flow distribution process, it is possible to simulate the differences in slurry distribution that may occur under the interference of uncertain factors. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram illustrating the principle of a distortion model provided in an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of a fracture generation domain and a cutoff frame and a fractured rock mass permeability calculation unit provided in an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of a 50° directional crack model truncation and correction provided in an embodiment of this application;

[0023] Figure 4 This is a schematic diagram of a 50° direction fracture network partitioning result provided in an embodiment of this application;

[0024] Figure 5 This is a schematic diagram of pore pressure provided in an embodiment of this application;

[0025] Figure 6 This is a schematic diagram of a point naming method within a crack provided in an embodiment of this application;

[0026] Figure 7 This is a schematic diagram of an equal volume method provided in an embodiment of this application;

[0027] Figure 8This is a schematic diagram of a fracture network before and after preprocessing, provided in an embodiment of this application.

[0028] Figure 9 This is a schematic diagram of flow net partitioning provided in an embodiment of this application;

[0029] Figure 10 This is a schematic diagram illustrating a simulation of slurry diffusion at different stages provided in an embodiment of this application;

[0030] Figure 11 This is a method provided in the embodiments of this application. 8-15 A schematic diagram showing the proportions of each volume within the interior;

[0031] Figure 12 This is a schematic diagram illustrating the effect of disturbance flow distribution on slurry diffusion, as provided in an embodiment of this application.

[0032] Figure 13 This is a schematic diagram of a slurry probability diffusion algorithm provided in an embodiment of this application. Detailed Implementation

[0033] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the following description will be provided in conjunction with the accompanying drawings and specific embodiments.

[0035] As described in related technologies, when the flow pattern and flow equations of grout within rock and soil masses change under different geological and construction conditions, simulation methods based on deterministic factors lack flexibility and produce poor simulation results. Therefore, there is an urgent need for a method that can simulate the distribution of grout within rock masses when its flow state is unknown.

[0036] To address the problems of the prior art, this application provides a method and apparatus for simulating slurry diffusion based on perturbation flow distribution. The slurry diffusion simulation method based on perturbation flow distribution provided in this application will be described first below.

[0037] The flow distribution method described in this application refers to determining the amount of grout to be injected by calculating the proportion of flow in each fracture, based on the flow rate and pressure values ​​at both ends of each fracture, while ensuring that the grout conforms to the flow law. This accurately simulates the final distribution of the grout within the fracture. Simultaneously, an interference factor is applied during the flow distribution process to simulate potential differences in grout distribution caused by uncertainties.

[0038] See Figure 1 The document illustrates a flowchart of the implementation of the slurry diffusion simulation method based on perturbation flow distribution provided in this embodiment of the application, which is described in detail below:

[0039] Step 110: Obtain the fracture statistics parameters of the target fractured rock mass.

[0040] Specifically, the statistical parameters of the fracture include the fracture length, fracture dip angle, and the distribution function parameters that the fracture center point follows.

[0041] Step 120: Based on the fracture statistics parameters, establish a random fracture network model for the target fractured rock mass.

[0042] Specifically, the fracture information in the random fracture network model includes fracture coordinates and fracture numbers.

[0043] Step 130: Perform mesh generation on the random fracture network model to obtain the mesh generation results.

[0044] Specifically, the mesh generation results include the mesh cell number, mesh point coordinates, mesh point number, mesh points and edges corresponding to the cracks and their numbers.

[0045] Step 140: Based on the unified pipeline network method and grid segmentation results, obtain the permeability results of the fractured rock mass before grouting.

[0046] Specifically, the permeability results of the fractured rock mass before grouting include the permeability coefficient, the pressure cloud map of the fractured rock mass, and the flow rate values ​​at various points within the fractured rock mass;

[0047] Step 150: Based on the grout probability diffusion algorithm based on perturbation flow distribution and the permeability results of the fractured rock mass before grouting, simulate the grouting situation of the target fractured rock mass through fracture network to obtain the grout diffusion simulation results of the target fractured rock mass.

[0048] The following section details how to simulate the grouting situation of the target fractured rock mass based on the grout probability diffusion algorithm of the permeability of the fractured rock mass before grouting, using the permeability results of the fractured rock mass before grouting.

[0049] 1) Preprocess the fracture network of the random fracture network model.

[0050] Specifically, the preprocessing involves breaking down all the fractures in the fracture network into smaller fractures with only their endpoints connected, based on intersections, divergences, and blind ends.

[0051] 2) Obtain the pressure value of each node and the flow rate value of each fracture in the preprocessed fracture network.

[0052] 3) Based on the pressure value of each node, the flow direction of the slurry in each fracture is obtained, and blind fractures and isolated fractures without slurry flow in the fracture network are eliminated.

[0053] 4) Divide the reduced fracture network into flow nets according to the flow direction of the grout in each fracture;

[0054] 5) Grouting is carried out on the divided flow network according to the flow distribution principle, the pressure value of each node and the flow value of each fracture. At the same time, a disturbance factor is applied during the grouting process to simulate the flow distribution of grout under the interference of uncertain factors.

[0055] Specifically, the traffic allocation principle can be:

[0056]

[0057]

[0058]

[0059] Where, α ij , It is the proportionality coefficient, Q ij Here, is the flow rate value, n is the number of fractures of the same order, ij is the node number at both ends of the fracture, μ is the mean, σ is the standard deviation, and V is the flow rate value. r V represents the volume of grout remaining after the upper-level fracture has been filled. ij To distribute the obtained slurry, α ij This is the proportionality coefficient.

[0060] Methods for controlling disturbance distribution: 1. First, calculate the distribution ratio α of each fracture within the same priority level according to equation (1.1). ij 2. Establish the slurry disturbance distribution function. Taking the slurry disturbance distribution as following a normal distribution function as an example, establish the distribution function as shown in equation (1.2), where μ is the distribution ratio α. ij σ is the standard deviation; 3. After establishing the distribution function, randomly sample from it as the new allocation ratio coefficient. 4. Substitute into equation (1.3) and recalculate the grout value V obtained from the crack. ij In short, it means controlling the value of the standard deviation σ in equation (1.2) so that the distribution ratio is controlled by α. ij Disturbance is Ultimately, this achieves the perturbation of the slurry flow distribution.

[0061] In some embodiments, after obtaining the slurry diffusion simulation results of the target fractured rock mass, the permeability results of the fractured rock mass after grouting can also be obtained based on the unified pipeline network method and the slurry diffusion simulation results of the target fractured rock mass. Furthermore, the permeability comparison results of the target fractured rock mass before and after grouting can be obtained based on the permeability results of the fractured rock mass before grouting and the permeability results of the fractured rock mass before grouting.

[0062] To facilitate understanding of the specific scheme of this application, the implementation process of each step is described in detail below.

[0063] 1.1 Collecting fracture statistical parameters

[0064] For the target fractured rock mass to be simulated for slurry flow, the statistical parameters of the fracture can be collected by plotting tables: fracture length, fracture dip angle, and the distribution function parameters obeyed by the fracture center point, as shown in Table 1.

[0065] Table 1. Statistical Table of Fracture Parameters

[0066]

[0067] 1.2 Establishing a stochastic fracture network model

[0068] Random fracture networks can be generated using a random fracture generation program. Different fracture network models can be randomly generated by controlling the mean and standard deviation of the fracture spacing distribution function, the mean and variance of the fracture length distribution function, and the mean and variance of the fracture dip angle distribution function.

[0069] The specific operation process is as follows:

[0070] 1) Input the parameters in Table 1 into the random crack generation program, and arbitrarily set the crack generation domain to, for example, 200×200;

[0071] 2) Establish a permeability calculation model for fractured rock masses, such as... Figure 2 (Right), Output the fracture network subdivision parameter table;

[0072] The process for selecting the permeability calculation unit for fractured rock mass is as follows: A 100×100 unit cutoff frame is established at the center of the fracture generation domain. Figure 2 (Left-center dashed box) The square area within the cut-off box is used as the permeability calculation unit model for fractured rock mass. The permeability model of each direction of the fracture is mainly obtained by rotating the cut-off box counterclockwise at a fixed angle, cutting out the model, and then correcting it, such as... Figure 2 As shown in the image on the right. Taking the study of the permeability of fractured rock mass at a 50° angle as an example, a corresponding fracture network model is established, such as... Figure 3 As shown in the image on the right.

[0073] 1.3 Mesh Generation

[0074] Input the fracture network model from Section 1.2 into the DFN mesh generation program, and the output fracture mesh generation results are as follows: Figure 4 As shown.

[0075] 1.4 Calculation of permeability coefficient of fractured rock mass before grouting

[0076] Input the analysis results from Section 1.3, fractured rock mass parameters, and slurry flowability-related parameters: fractured rock mass permeability (m2), porosity, fracture width (mm), fluid viscosity (Pa·s) and density (kg / m3), and boundary setting conditions (head difference) into the unified pipeline method calculation program;

[0077] Output the calculation results of fracture permeability before grouting—permeability coefficient K and flow rate Q of each fracture. i and pore pressure value P i And draw a pore pressure cloud map as follows Figure 5 .

[0078] 1.5 Simulation of slurry diffusion based on perturbation flow distribution

[0079] Based on the stochastic fracture network model established in Section 1.2 and the calculation results in Section 1.4, the grouting situation of the fracture network is simulated.

[0080] Pretreatment involves breaking all cracks into smaller cracks with only their endpoints connected, based on intersections, divergences, and blind ends. Figure 6 The fissure formed by midpoint 1 and midpoint 14 is divided into six fissures: fissures 1-6, fissures 6-12, and fissures 12-14. Similarly, the fissures formed by midpoints 3 and 10, midpoints 2 and 15, midpoints 5 and 9, and midpoints 11 and 13 are all broken into smaller fissures.

[0081] In simulated grouting, it is assumed that the grout volume is incompressible, and grouting is performed using the isovolume method. Simultaneously, the grout movement follows flow laws. The isovolume method refers to the volume ratio of each grouted fracture as follows: Figure 7 That is, the ratio of the volume of grout to the volume of the crack being filled is 1:1.

[0082] The law of slurry flow refers to:

[0083] 1) The slurry always flows from the area of ​​high pore pressure to the area of ​​low pore pressure. The pressure values ​​at each point are calculated from Section 1.4.

[0084] 2) Grout will only continue to flow to other fractures that intersect with the fracture once the fracture is filled.

[0085] by Figure 6For example, grout will only be distributed to fissures 6-7 and 6-12 when fissure 1-5 is filled; 3) Grout is distributed hierarchically within the fissure network. Hierarchical distribution means that fissures are divided into different priorities according to the order in which they come into contact with grouting holes or intersecting fissures, and grout is uniformly distributed according to different priority levels. Figure 7 The order of the cracks when the grout is distributed in stages is shown in Table 2.

[0086] Table 2 Allocation Order Table

[0087] Crack level Crack number Level 1 1-6、2-4 Level 2 6-5、6-7、6-12、4-7、4-8、4-3 Level 3 7-8、7-10、8-9、8-15、12-11、12-13、12-14 Level 4 8-9、8-15

[0088] The flow distribution principle means that after the upper-level fracture is filled, the proportion of the remaining grout flowing to the lower-level connected fractures must be equal to the proportion of the flow rates between the fractures, as shown in the following formula:

[0089]

[0090]

[0091]

[0092] Where, α ij , It is the proportionality coefficient, Q ij Here, is the flow rate value, n is the number of fractures of the same order, ij is the node number at both ends of the fracture, μ is the mean, σ is the standard deviation, and V is the flow rate value. r V represents the volume of grout remaining after the upper-level fracture has been filled. ij To distribute the obtained slurry, α ij This is the proportionality coefficient.

[0093] by Figure 6 Taking the fracture network shown as an example, the grouting simulation process is as follows:

[0094] 1) For ease of understanding, the crack is named l based on the node numbers at both ends. ij Where ij indicates that the pressure at node i is greater than that at node j; the volume of each fracture is named F. ij The volume of grout injected into each fracture is V. ij The flow rate of each fracture is Q. ij .like Figure 8 The middle fractures 1-6 are l 1-6 Crack volume F 1-6 The volume of grout injected is V 1-6 The traffic is Q 1-2 ;

[0095] 2) Fracture network preprocessing;

[0096] 3) Obtain the pressure value P of each node. iand the flow rate Q of each fracture ij ;

[0097] 4) Based on the pressure value P of each node i The flow direction of the grout in each fracture is obtained, and blind fractures and isolated fractures without grout flow are removed (taking the blind fracture composed of endpoint 3 and node 4 as an example, in this case P3>P4, the grout does not flow in this fracture, so it is removed), thus obtaining Figure 8 (b);

[0098] 5) Based on different flow directions, Figure 8 (b) Slit networks are divided into, for example, Figure 9 The flow mesh No. 1 and flow mesh No. 2 are shown. Next, grouting will be carried out on flow mesh No. 1 and flow mesh No. 2 respectively.

[0099] Taking Stream 1 as an example:

[0100] According to the flow distribution principle, i.e., formula, with the crack l 1-6 Based on the flow rate ratio of crack l2-4, the total slurry volume V is allocated to flow network 1 and flow network 2.

[0101] Assume the volume of slurry distributed by flow net No. 1 is V. 1-6 , crack l 1-6 For F 1-6 (Assume V) 1-6 >F 1-6 If it flows into the fissure l 6-7 , l 6-12 The total volume of the slurry is V 1-6 –F 6-12 =Vr, at this time the fracture grouting situation is as follows Figure 10 (a); then with crack l 6-7 l 6-12 Substituting the flow rate value into equation (1.1), without any disturbance, the command... Substituting into equation (1.3), allocate V r The infusion situation at this time is as follows Figure 10 (b); then with the crack l 7-8 l 12-13 l 12-14 The corresponding flow rate is allocated, and the perfusion situation is as follows: Figure 10 (c); Final injection of fracture l 8-15 The infusion situation at this time is as follows Figure 10 (d);

[0102] When performing injection simulation on flow network No. 2, to avoid issues such as cracks... 8-15 When two conflicting allocation orders occur, a new parameter is assigned to each fracture—the remaining fillable volume V of the fracture. z When the fracture network is not grouted, V zThe initial value is equal to the volume value V of the corresponding small crack. ij As the amount of grouting in the fissure gradually increases, its value gradually approaches 0. When grouting the fissure in the future, it is regarded as a fully grouted fissure.

[0103] Then introduce the remaining fillable volume V in the fracture. z Subsequently, the grouting process for flow network No. 2 became:

[0104] 1) Fill the fissure l 2-4 Correcting cracks 2-4 The remaining fillable volume is 0;

[0105] 2) Fill the cracks 4-7 and l 4-8 Correcting cracks 4-7 and l 4-8 The remaining fillable volume is 0;

[0106] 3) Filling the fissures 7-8 and l 8-15 At this time, in l 7-8 Before it is filled, the fissure l 8-15 The slurry comes from the cracks. 4-8 Assuming the crack is l at this time 8-15 The volume of the slurry is F 8-15 Then the crack l 8-15 The remaining fillable volume V z For V 8-15 -F 8-15 >0;

[0107] 4) Fill the cracks 7-8 : Crack l 8-15 The slurry originates from the cracks. 7-8 and l 4-8 Ultimately 8-15 All slurry sources and their volume percentages are represented as follows: Figure 11 As shown.

[0108] It should be noted that the perturbation flow distribution is achieved by adjusting α in equation (1.1) during the slurry distribution process. ij Applying a disturbance becomes a new To achieve disturbed distribution of slurry.

[0109] The specific method is as follows: assuming the slurry flow follows a certain distribution function, setting the standard deviation σ to 0.5, and using α... ij The value is taken as the mean μ of the distribution function. The distribution function of equation (1.2) is established, and random sampling is performed. The sampling results are then used to establish the distribution function. Substitute into equation (1.3) to calculate the amount of slurry after redistribution.

[0110] by Figure 12For example, assuming the slurry flow follows a normal distribution function, the process of applying a disturbance is as follows:

[0111] 1) In Figure 12 In the middle, assuming crack l 23 , l 24 The flow ratio was 1:3, and the fracture volumes were 3 and 2, respectively; the injection volume into the fracture was 1. 23 , l 24 The total amount of slurry is V r =4;

[0112] 2) Without applying a disturbance factor, the crack l 23 , l 24 The amount of slurry distributed is calculated according to the flow rate using formulas 1 and 3;

[0113] 3) With crack l 23 , l 24 The flow rate is 0.25 and 0.75, which are the mean μ. Let σ = 0.5 and substitute them into equation (1.2) to establish the sampling function.

[0114] 4) Perform random sampling, use the sampled value as the disturbed slurry volume, and re-simulate the slurry distribution at this time, as shown below. Figure 12 As shown in (b).

[0115] like Figure 13 As shown, a slurry diffusion simulation process based on perturbation flow distribution is illustrated.

[0116] 1.6 Permeability Coefficient Calculation

[0117] This model employs a unified pipe network method for permeability coefficient calculation. The pipe network system equates fractures to one-dimensional fractured conduits and the rock matrix to one-dimensional matrix conduits. In establishing the grouting model, only two fluids (water and grout) are considered flowing within the rock mass, and the hydraulic parameters for water and grout differ between the two types of conduits. Considering the permeability of rock mass to water and grout in actual engineering, it is assumed that water flows through fractured conduits and rock matrix conduits, while grout flows solely through fractures. Therefore, after grouting, only the permeability of water through fractured conduits within the rock mass is altered, while the matrix conduits remain unaffected.

[0118] After grouting, the permeability coefficient of the grout in the fissure tube to water is modified as follows: Assume the amount of grout distributed in each fissure is V. j The amount of grout injected into the rock mass is V. 总 =ΣV jAfter grouting, the fissures can be divided into fully grouted fissures, semi-grouted fissures, and ungrouted fissures. Assume that the permeability coefficient of the fissure to water is K1, and the permeability coefficient of the grout stone body to water is K2. Then the permeability coefficient of the fully grouted fissure to water changes from K1 to K2; the ungrouted fissure still maintains the original permeability coefficient K1; for the permeability coefficient K3 of the semi-grouted fissure to water, it is determined according to the volume ratio of the grout in the fissure. The calculation of K3 is as follows: Assume that the volume of a certain semi-grouted fissure is V, and the volume of the grout in this fissure is V 浆 , where (V 浆 <V), then the permeability coefficient of this fissure to water is calculated by the following formula (3):

[0119]

[0120] The calculation process of the permeability coefficient of the unit body is as follows:

[0121] 1) The calculation unit selects a two-dimensional square random fissure with a generation domain of 200×200 and a calculation domain of 100×100, as Figure 8 .

[0122] 2) The left boundary of the unit body is the inflow boundary of water and grout; the right boundary is the corresponding outflow boundary; the upper and lower boundaries are impermeable boundaries during the calculation of the permeability coefficient.

[0123] 3) The fissures in the unit body are smooth and straight fissures, which do not expand and do not generate new fissures under pressure.

[0124] 4) The calculation of the permeability coefficient follows Darcy's law, which is formula (4):

[0125]

[0126] Among them, K is the permeability coefficient, Q is the flow rate, L is the length, ΔP is the pressure difference between the left and right boundaries of the unit body, and A is the area passed by the fluid per unit. Note: For a two-dimensional unit body, the unit thickness is taken as 1, so A = L·1.

[0127] In this embodiment, for the target fractured rock mass whose grout distribution is to be simulated, the following steps are taken: First, the fracture statistical parameters of the target fractured rock mass are obtained. Then, based on the fracture statistical parameters, a random fracture network model of the target fractured rock mass is established. Next, the random fracture network model is meshed to obtain the meshing results. Then, based on the unified pipeline method and the meshing results, the permeability results of the fractured rock mass before grouting are obtained. Finally, based on the grout probability diffusion algorithm based on perturbation flow distribution and the permeability results of the fractured rock mass before grouting, the grouting situation of the target fractured rock mass is simulated to obtain the grout diffusion simulation results of the target fractured rock mass. Thus, a method is provided that can simulate the distribution of grout within a rock mass when the flow state is unknown. Because an interference factor is applied during the flow distribution process, it is possible to simulate the differences in grout distribution that may occur under the interference of uncertain factors.

[0128] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0129] The following are device embodiments of this application. For details not described in detail, please refer to the corresponding method embodiments described above.

[0130] The slurry diffusion simulation device based on perturbation flow distribution in this application embodiment includes:

[0131] The fracture statistical parameter acquisition module is used to acquire the fracture statistical parameters of the target fractured rock mass; among which, the fracture statistical parameters include fracture length, fracture dip angle, and the distribution function parameters obeyed by the fracture center point;

[0132] The model building module is used to build a random fracture network model of the target fractured rock mass based on fracture statistical parameters; the fracture information of the random fracture network model includes fracture coordinates and fracture numbers;

[0133] The mesh generation module is used to perform mesh generation on the random fracture network model and obtain the mesh generation results. The mesh generation results include the mesh cell number, mesh point coordinates, mesh point number, mesh points and edges corresponding to the fractures and their numbers.

[0134] The generation module is used to obtain the permeability results of fractured rock mass before grouting based on the unified pipeline network method and grid subdivision results; among which, the permeability results of fractured rock mass before grouting include permeability coefficient, pressure cloud map of fractured rock mass, and flow rate values ​​at various points in fractured rock mass;

[0135] The slurry diffusion simulation module is used to simulate the grouting situation of the target fractured rock mass based on the slurry probability diffusion algorithm based on the permeability of the fractured rock mass before grouting, and to obtain the slurry diffusion simulation results of the target fractured rock mass.

[0136] In some embodiments, the slurry diffusion simulation module is also used for:

[0137] The fracture network of the random fracture network model is preprocessed; the preprocessing includes breaking all the fractures in the fracture network into small fractures with only their endpoints connected by intersections, divergences and blind ends.

[0138] Obtain the pressure value of each node and the flow rate value of each fracture in the preprocessed fracture network;

[0139] Based on the pressure values ​​of each node, the flow direction of the slurry in each fracture is obtained, and blind fractures and isolated fractures without slurry flow in the fracture network are eliminated.

[0140] Based on the flow direction of the slurry in each fracture, the reduced fracture network is divided into flow nets;

[0141] Based on the flow distribution principle, the pressure value of each node, and the flow value of each fracture, the divided flow network is grouted. At the same time, a disturbance factor is applied during the grouting process to simulate the flow distribution of grout under the interference of uncertain factors.

[0142] In some embodiments, traffic allocation principles include:

[0143] Once the upper-level fracture is filled, the proportion of the remaining grout flowing to each connected fracture in the lower level is equal to the proportion of the flow rate between each connected fracture in the lower level.

[0144] In some embodiments, the slurry diffusion simulation module is specifically used for:

[0145] For the volume of grout to be injected into each crack in the flow network, random sampling is performed using the distribution function obeyed by the grout flow, and the obtained sampling value is used as the disturbed grout volume of the corresponding crack.

[0146] Based on the volume of slurry after disturbance of each crack in the flow net, the flow distribution of slurry under the interference of uncertain factors is simulated.

[0147] In some embodiments, traffic allocation principles include:

[0148] (when no disturbance occurs) )

[0149] Where, α ij , It is the proportionality coefficient, Qij V represents the flow rate value, n represents the number of fractures of the same order, ij represents the node numbers at both ends of the fracture, and V represents the flow rate value. r V represents the volume of grout remaining after the upper-level fracture has been filled. ij To distribute the obtained slurry.

[0150] The mean μ of the distribution function obeyed by the slurry flow is the proportionality coefficient α. ij The standard deviation σ is a preset value.

[0151] In some embodiments, the distribution function obeyed by the slurry flow includes:

[0152]

[0153] Where σ is the standard deviation and the mean μ is the proportionality coefficient α. ij .

[0154] In some embodiments, the slurry diffusion simulation device based on perturbation flow distribution further includes a comparison module for:

[0155] Based on the unified pipeline network method and the grout diffusion simulation results of the target fractured rock mass, the permeability results of the fractured rock mass after grouting were obtained;

[0156] Based on the permeability results of the fractured rock mass after grouting and before grouting, a comparison of the permeability of the target fractured rock mass before and after grouting was obtained.

[0157] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0158] Furthermore, the features of the embodiments shown in the accompanying drawings or the various embodiments mentioned in this specification should not be construed as independent embodiments. Rather, each feature described in one example of an embodiment can be combined with one or more other desired features from other embodiments to produce other embodiments not described in words or with reference to the accompanying drawings.

[0159] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0160] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method of simulating slurry diffusion based on perturbed flow distribution, characterized by, The method comprises the following steps: obtaining fracture statistical parameters of a target fractured rock mass; wherein the fracture statistical parameters include fracture length, fracture dip angle and distribution function parameters of fracture center points; establishing a random fracture network model of the target fractured rock mass according to the fracture statistical parameters; wherein fracture information of the random fracture network model includes fracture coordinates and fracture numbers; performing grid division on the random fracture network model to obtain a grid division result; wherein the grid division result includes grid element numbers, grid point coordinates, grid point numbers, grid points and edges corresponding to fractures and their numbers; obtaining a pre-grouting fractured rock mass permeability result according to the unified pipe network method and the grid division result; wherein the pre-grouting fractured rock mass permeability result includes a permeability coefficient, a fracture rock mass pressure cloud chart and flow values at each position in the fracture rock mass; performing fracture network grouting simulation on the target fractured rock mass according to a slurry probability diffusion algorithm based on perturbed flow distribution and the pre-grouting fractured rock mass permeability result to obtain a slurry diffusion simulation result of the target fractured rock mass.

2. The method of claim 1, wherein, The fracture network grouting simulation on the target fractured rock mass according to the slurry probability diffusion algorithm based on perturbed flow distribution and the pre-grouting fractured rock mass permeability result comprises the following steps: preprocessing a fracture network of the random fracture network model; wherein the preprocessing comprises scattering all fractures of the fracture network into small fractures with only end points connected to each other at intersection points, branch points and blind end points of the fractures; obtaining pressure values of each node in the preprocessed fracture network and flow values of each fracture; obtaining flow directions of slurry in each fracture according to the pressure values of each node and deleting blind end fractures and isolated fractures in the fracture network without slurry flow; performing flow network division on the deleted fracture network according to the flow directions of slurry in each fracture; performing grouting on the divided flow network according to flow distribution principles, the pressure values of each node and the flow values of each fracture, and applying a perturbation factor in the grouting process to simulate flow distribution of slurry under interference of uncertain factors.

3. The method of claim 2, wherein, The flow distribution principles comprise the following: when an upper fracture is filled, the proportion of remaining slurry flowing to each connected lower fracture is equal to the proportion of flow between each connected lower fracture.

4. The method of claim 3, wherein, The application of the perturbation factor in the grouting process to simulate flow distribution of slurry under interference of uncertain factors comprises the following steps: for each fracture in the flow network, random sampling is performed on the volume of slurry to be grouted by using a distribution function to which slurry flow is subjected, and the obtained sampling value is taken as the perturbed slurry volume of the corresponding fracture; flow distribution of slurry under interference of uncertain factors is simulated according to the perturbed slurry volume of each fracture in the flow network.

5. The method of claim 4, wherein, The perturbed flow distribution principle comprises the following: where V r is the volume of the remaining slurry after the upper fracture is filled, n is the number of fractures of the same order, V ij is the volume of the obtained slurry, ij is the node number of both ends of the fracture, a ij is a proportional coefficient, Q ij is the flow value in the fracture ij, f(x) is a distribution function to which the slurry flow is subjected, μ is a ij , and σ is a standard deviation.

6. The method of slurry diffusion simulation based on perturbation flow allocation of claim 1, wherein, The method further comprises the following steps: obtaining a post-grouting fractured rock mass permeability result according to the unified pipe network method and the slurry diffusion simulation result of the target fractured rock mass; obtaining a permeability comparison result of the target fractured rock mass before and after grouting according to the post-grouting fractured rock mass permeability result and the pre-grouting fractured rock mass permeability result.

7. A slurry diffusion simulation apparatus based on perturbed flow distribution, characterized by, The method comprises the following steps: The fissure statistical parameter acquisition module is configured to acquire fissure statistical parameters of a target fissure rock mass, wherein the fissure statistical parameters include fissure length, fissure inclination angle, and distribution function parameters of fissure center points. The model establishment module is configured to establish a random fissure network model of the target fissure rock mass according to the fissure statistical parameters, wherein fissure information of the random fissure network model includes fissure coordinates and fissure numbers. The grid division module is configured to perform grid division on the random fissure network model to obtain a grid division result, wherein the grid division result includes grid unit numbers, grid point coordinates, grid point numbers, grid points corresponding to fissures, and edges and numbers thereof. The generation module is configured to obtain fissure rock mass permeability results before grouting according to the unified pipe network method and the grid division result, wherein the fissure rock mass permeability results before grouting include a permeability coefficient, a fissure rock mass pressure cloud chart, and flow values at all places in the fissure rock mass. The slurry diffusion simulation module is configured to simulate fissure network grouting of the target fissure rock mass according to a slurry probability diffusion algorithm based on perturbed flow distribution and the fissure rock mass permeability results before grouting to obtain slurry diffusion simulation results of the target fissure rock mass.

8. The perturbed flow distribution based slurry diffusion simulation apparatus of claim 7, wherein, The slurry diffusion simulation module is further configured to: perform preprocessing on the fissure network of the random fissure network model, wherein the preprocessing includes scattering all fissures of the fissure network into small fissures with only end points interconnected at intersection points, bifurcation points, and blind end points of fissures; acquire pressure values of each node in the preprocessed fissure network and flow values of each fissure; obtain flow directions of slurry in each fissure according to the pressure values of each node, and delete blind end fissures and isolated fissures in the fissure network in which slurry does not flow; perform flow network division on the deleted fissure network according to the flow directions of slurry in each fissure; perform grouting on the divided flow network according to flow distribution principles, the pressure values of each node, and the flow values of each fissure, and apply a perturbation factor in the grouting process to simulate flow distribution of slurry under interference of uncertain factors.

9. The perturbed flow distribution based slurry diffusion simulator of claim 8, wherein, The flow distribution principles include: when an upper fissure is filled, the proportion of remaining slurry flowing to each connected fissure of a lower fissure is equal to the proportion of flow between each connected fissure of the lower fissure.

10. The perturbed flow distribution based slurry diffusion simulation apparatus of claim 7, wherein, The device further includes a comparison module configured to: obtain fissure rock mass permeability results after grouting according to the unified pipe network method and the slurry diffusion simulation results of the target fissure rock mass; obtain a permeability comparison result of the target fissure rock mass before and after grouting according to the fissure rock mass permeability results after grouting and the fissure rock mass permeability results before grouting.

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