Rock mass grouting simulation method and system based on solid-liquid connection

Abstract

The invention provides a rock mass grouting simulation method and system based on solid-liquid linkage, and relates to the technical field of rock mass grouting simulation.The method comprises the steps that the change relation of density along with time in the solidification process of slurry to be grouted is obtained, and an evolution model of the slurry density and time is established; the solidification process of the to-be-grouted slurry is divided into a plurality of stages, and the physical property of each stage in the solidification process of the to-be-grouted slurry is obtained; and on the basis of the obtained evolution model of the slurry density and the time and the physical property of each stage in the solidification process of the slurry to be grouted, parameters of corresponding time in the rock mass grouting simulation process are changed, and rock mass grouting simulation is carried out. According to the method, the accuracy of the simulation calculation process of geotechnical engineering such as rock mass grouting can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of rock mass grouting simulation, and in particular to a rock mass grouting simulation method and system based on solid-liquid connection. Background Art

[0002] Numerical calculations in geotechnical engineering often involve complex geological conditions involving liquid and solid matter. For example, grouting operations are not considered complete rock, but rather contain a complex network of fractures. These fractures reduce the stability of the rock mass, necessitating grouting to fill these fractures with slurry and thereby reinforce the rock mass.

[0003] In the related art, the liquid and solid states of the slurry before and after solidification are usually calculated separately, which makes it impossible to connect the calculations of the liquid and solid stages. The calculation process is cumbersome, and when calculating in stages, it is difficult to determine where the liquid material is converted into solid material, and thus it is difficult to determine the diffusion range of the liquid material. In response to this, the existing technology proposes a solution based on the viscosity of the slurry, which determines whether the slurry is in a liquid or solid state based on the viscosity of the slurry. However, this solution ignores the errors caused by the friction generated by the rotation of the rotor during the acquisition of data such as the slurry viscosity and the shear rheology model, as well as the errors caused by the entire process of the change in the material morphology that affects the calculation results. Summary of the Invention

[0004] In order to address the deficiencies of the prior art, the present invention aims to provide a rock grouting simulation method and system based on solid-liquid connection to improve the accuracy of geotechnical engineering simulation calculation processes such as rock grouting.

[0005] To achieve the above objectives, according to some embodiments, a first aspect of the present invention provides a rock grouting simulation method based on solid-liquid connection, comprising: Obtain the relationship between the density of the grouting slurry and time during its solidification process, and establish a slurry density and time evolution model; The solidification process of the grouting slurry to be injected is divided into multiple stages, and the physical properties of each stage of the solidification process of the grouting slurry to be injected are respectively obtained; Based on the obtained slurry density and time evolution model and the physical properties of each stage in the solidification process of the slurry to be grouting, the parameters corresponding to the time in the rock grouting simulation process are changed to perform rock grouting simulation.

[0006] A second aspect of the present invention provides a rock grouting simulation system based on solid-liquid connection, comprising: The model building module is configured to obtain the relationship between the density of the grouting slurry and time during the solidification process, and to establish an evolution model of the slurry density and time; The slurry property acquisition module is configured to divide the solidification process of the slurry to be grouted into multiple stages and respectively acquire the physical properties of each stage of the solidification process of the slurry to be grouted; The rock grouting simulation module is configured to change the parameters corresponding to the time in the rock grouting simulation process based on the obtained slurry density and time evolution model and the physical properties of each stage in the solidification process of the slurry to be grouting, so as to perform rock grouting simulation.

[0007] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a rock grouting simulation method and system based on solid-liquid connection. In the rock grouting simulation, slurry density is used as an indicator to judge the slurry material form, and through a combination of experiments and simulation calculations, the relationship between the density change of the slurry from liquid to solid with time is obtained through slurry migration experiments, and an evolution model of slurry density and time is established, thereby guiding the change of slurry parameters at different time points in the rock grouting simulation process, realizing the connection calculation when the solid-liquid form changes during the simulation process. At the same time, compared with slurry viscosity, slurry density has smaller error in data acquisition and is easier to measure when the slurry form changes, thereby improving the accuracy of the rock grouting simulation process.

[0008] Advantages of additional aspects of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0010] Figure 1 Schematic diagram of the process of the method in embodiment 1 of the present invention; Figure 2 Schematic diagram of a microscopic scan of the internal fracture network of a fractured rock mass during grouting operation in Example 1 of the present invention.

[0011] Among them, 1. slurry; 2. grouting hole; 3. fractured rock mass; 4. fracture. DETAILED DESCRIPTION

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0013] Example 1 The first embodiment of the present invention provides a rock grouting simulation method based on solid-liquid connection, such as Figure 1-Figure 2 As shown, including: S1. Obtain the relationship between the density of the grouting slurry and time during its solidification process, and establish an evolution model of the slurry density and time; S2. Dividing the solidification process of the grouting slurry to be injected into multiple stages, and obtaining the physical properties of each stage of the solidification process of the grouting slurry to be injected; S3. Based on the obtained slurry density and time evolution model and the physical properties of each stage in the solidification process of the slurry to be grouting, the parameters corresponding to the time in the rock grouting simulation process are changed to perform rock grouting simulation.

[0014] To simplify the description, the method provided in this embodiment is described below using geotechnical engineering grouting operations as an example. Figure 2 As shown, it is assumed that the slurry 1 used is slurry A, and the proportions of its various substances are fixed; the geotechnical engineering numerical calculation software used is software B, and numerical calculations and simulations of the rock grouting process can be realized in software B. In some embodiments, the slurry 1 is a cement slurry commonly used in geotechnical engineering grouting operations, which can evolve into a variety of other modified slurries, but its various properties must have laboratory-measurable characteristics, otherwise it is difficult to apply to numerical calculations. The fissures 4 are complex, crisscrossing fissure network channels existing in the fractured rock mass 3. The slurry 1 is injected into the fissures 4 of the fractured rock mass 3 from the grouting hole 2, diffuses in the fissures 4, and gradually fills all the fissures 4 of the fractured rock mass 3 until the slurry 1 no longer flows and is completely solidified, thereby playing a role in reinforcing the fractured rock mass 3.

[0015] During the slurry solidification process, numerical calculations are often used to describe the grouting process in order to accurately reflect the diffusion, sealing, and reinforcement effects of the slurry. However, as the slurry transforms from liquid to solid, its physical and mechanical parameters change, making the numerical calculation process complex. Furthermore, the calculations can only be performed in stages based on the states before and after solidification, making it difficult to connect the two-stage calculation processes.

[0016] In this regard, this embodiment proposes to use slurry density as an indicator to judge the morphology of slurry materials, combining experiments with numerical calculations. First, through laboratory slurry migration tests, the changing pattern of slurry solidification is obtained, and a slurry density and time evolution model is established to obtain the parameters required for numerical calculation. Subsequently, the relevant parameters required for numerical calculation at different time points are determined based on the slurry density and time evolution model, and input into the B software used for numerical calculation for calculation. The entire process of slurry A solidifying from liquid to solid is taken into account in the calculation process, which connects the liquid and solid transformation processes of slurry A and simplifies the calculation process, thereby determining the final position of the flow of liquid slurry A, that is, clarifying the final diffusion range of liquid slurry A. Measuring density by the mass volume method can avoid the error caused by the friction generated by the rotor rotation during the acquisition of data such as slurry viscosity and shear rheology model in solutions based on slurry viscosity. When instruments such as rotational viscometers and rotational rheometers are used to test the viscosity and shear rheology of slurries, they have a disc rotor or cylindrical rotor that can rotate in the slurry. When this rotor rotates in the slurry, friction is generated between the rotor and the slurry. At the same time, the disturbance of the slurry itself by the rotation of the rotor may also change the progress of the hydration reaction in the slurry. Judging the state of the slurry based on density does not introduce errors caused by measurement, thereby improving the accuracy of the simulation calculation. In addition, the entire process of the slurry solidifying from liquid to solid is calculated during the calculation process of this embodiment, reducing the error caused by ignoring the process of liquid solidification to solid in previous solutions.

[0017] In step S1, by adding a density measurement device based on the mass volume method to the slurry migration test equipment, the density change data of the slurry from liquid to solid in the migration test is collected over time, thereby establishing a slurry density and time evolution model.

[0018] The density measuring device based on the mass volume method is installed on the slurry migration channel in the slurry migration test equipment. The device calculates the instantaneous density data at the installation location of the measuring device in real time based on the ratio of the slurry mass at the installation location to the pipeline volume. The time interval for each calculation is 1 second.

[0019] During the slurry migration test, density data was acquired in seconds, ultimately yielding per-second slurry density data, representing the time-dependent slurry density change during the test. This data was used to establish a slurry density and time evolution model. Statistical correlation methods were used to analyze patterns and trends in the data, identifying and fitting a mathematical model that best fits the data.

[0020] The established slurry density and time evolution model is a mathematical model of slurry density change over time. In this embodiment, based on the analysis results of the slurry density change over time data, it is assumed that the data conforms to the mathematical model of the following equation: ; Where ρ represents the slurry density (unit is kilograms per cubic meter, kg / m 3 ), t represents time (dimension is second, s), the value of t is taken as zero point at the start time of the test, a1, a2, a3, ..., a n is a constant parameter of the fitting.

[0021] Based on the acquired data on the slurry density variation over time, a model is fitted to solve for all constant parameters. This model is not unique; the optimal solution is the one that captures the widest range of density variation over time. If the model captures fewer slurry density variation data per second, other mathematical models (such as exponential functions, logarithmic functions, and Fisher distribution functions) can be used to fit the model until the optimal solution is found.

[0022] In step S2, the entire solidification process of the slurry is divided into four time points according to the solidification and coagulation characteristics of the slurry: (1) Hydration reaction starting time t1: The slurry has fluidity and plasticity at the initial stage of solidification and coagulation. The starting time of this process is recorded as the hydration reaction starting time point, which is based on the starting time of the laboratory test.

[0023] (2) Initial setting time t2: The slurry gradually loses fluidity and plasticity over time. The initial setting time obtained in the laboratory shall prevail.

[0024] (3) Final setting time t3: After initial setting, the cement slurry gradually hardens and its strength increases until it evolves into a hard solid substance. The final setting time obtained in the laboratory shall prevail.

[0025] (4) Time t4 for completion of standard condition curing: that is, the slurry-solidified stone body after final setting is cured under standard conditions, and the curing completion time is recorded as t4.

[0026] The slurry density at four time points was obtained in the laboratory: ρ t1 , ρ t2 , ρ t3 , ρ t4 .

[0027] Based on the density change, it is divided into four stages according to the above four time points: Stage 1: Slurry density is at ρ t1 ~ρ t2When the temperature is within the specified range, the slurry is in liquid state and still has fluidity and plasticity; Stage 2: Slurry density is at ρ t2 ~ρ t3 When it is within the range, the slurry has lost its fluidity and has a certain strength; Stage 3: Slurry density is at ρ t3 ~ρ t4 When the stone is within the range, the strength of the stone solidified by the slurry gradually increases in this stage; Stage 4: Slurry density reaches ρ t4 During the subsequent test time, the slurry in this stage has completely solidified and has developed structural strength.

[0028] In Phase 1, laboratory experiments were conducted on the slurry, with data recorded every second. Using the same method as used to obtain the slurry density and time evolution model in Step S1, mathematical models were developed to demonstrate the time-dependent relationships between the slurry's fluidity, permeability, flow rate, cohesion, and bulk modulus (liquid-related parameters obtained from laboratory studies can be adjusted based on the needs of different numerical simulation software). For ease of distinction, the fluidity, permeability, flow rate, cohesion, and bulk modulus of the slurry in the liquid state are referred to below as the first physical parameters.

[0029] For stage 2, laboratory tests were conducted on the slurry to obtain the slurry's strength, stiffness, elastic modulus, porosity, Poisson's ratio, cohesion, and internal friction angle parameters at time t2. (Parameters obtained from laboratory studies can be adjusted as needed in different numerical simulation software.) For ease of distinction, the slurry's strength, stiffness, elastic modulus, porosity, Poisson's ratio, cohesion, and internal friction angle parameters in the solid state are referred to below as the second physical parameters.

[0030] For stage 3, laboratory tests were conducted on the slurry to obtain the strength, stiffness, elastic modulus, porosity, Poisson's ratio, cohesion, and internal friction angle parameters of the slurry at time point t3 (the parameters obtained from laboratory studies can be adjusted according to the needs of different numerical simulation software).

[0031] For stage 4, laboratory test studies are conducted on the slurry to obtain the strength, stiffness, elastic modulus, porosity, Poisson's ratio, cohesion, and internal friction angle parameters of the slurry at time point t4 (the parameters obtained from laboratory studies can be adjusted according to the needs of different numerical simulation software).

[0032] In step S3, first, in software B, the grouting pressure, surrounding rock pressure in all directions, and the strength, stiffness, elastic modulus, porosity, Poisson's ratio, cohesion, and internal friction parameters of the fractured rock mass to be simulated are input according to the project requirements. Then, based on the slurry density and time evolution model obtained in step S1 and the physical properties of the slurry at each stage of the solidification process obtained in step S2, the slurry parameters are changed during the grouting simulation to proceed with the rock mass grouting simulation.

[0033] The rock grouting simulation in this embodiment is based on the evolution model of density and time, and in step S2, a mathematical model of the correlation between the first physical parameter of the slurry in the liquid state (stage 1) and time is obtained. However, there will be errors between the time in the numerical simulation software and the time in the experiment, and they are not consistent every second. Therefore, the time relationship between the two needs to be corrected. The specific operation is as follows: Taking the change time of the slurry fluidity as an example, the time when the slurry fluidity reaches the same value in the experiment and the numerical simulation is recorded respectively, and then the relationship between the two times is recorded at this time. Assuming that the slurry fluidity is x (its dimension depends on the test instrument selected by the laboratory, but its numerical range remains unchanged), the time when the slurry fluidity reaches x in the experiment is recorded as m, and the time when the slurry fluidity reaches x in the numerical simulation is recorded as n. For each change in the slurry fluidity x, the m and n values ​​have corresponding changes. Using the same approach as establishing the slurry density and time evolution model in step S1, mathematical models for the variation of x with m within a numerical range are fitted, denoted as equation M, and for the variation of x with n within a numerical range, denoted as equation N. Since the numerical range of x remains constant, M = N can be set to obtain the relationship between m and n, and thus a mathematical model for the correlation between fluidity and time after time error correction is obtained. The time errors of other parameters (permeability, flow rate, cohesion, and bulk modulus of the slurry in the liquid state; strength, stiffness, elastic modulus, porosity, Poisson's ratio, cohesion, internal friction angle, and slurry density of the slurry in the solid state) are also corrected in this manner.

[0034] The mathematical model of the slurry density change over time obtained in step S1, after time error correction, is used as the density data of the slurry during the entire grouting simulation process and input into software B for simulation (using programming methods such as Matlab program and Fish language, the same below). During the grouting simulation process, the density change is used as the judgment basis to set the parameters of the grouting simulation respectively: (1) When the density value is in stage 1, that is, the density is in the range ρ t1 ~ρ t2 At this time, the slurry is a liquid substance with fluidity. For the flow parameters of the slurry, a mathematical model of the correlation between the fluidity, permeability, flow rate, cohesion, bulk modulus and time of the slurry in the liquid state after the time error correction is input.

[0035] (2) When the density value is in stage 2, that is, the density is in the range ρ t2 ~ρ t3 At t2, the slurry has initially solidified and is studied as a solid substance. The strength, stiffness, elastic modulus, porosity, Poisson's ratio, cohesion, and internal friction angle parameters of the slurry at time point t2 after time error correction are input.

[0036] (3) When the density value is in stage 3, that is, the density is in the range ρ t3 ~ρ t4 At time t3, the slurry has finally set, and the strength, stiffness, elastic modulus, porosity, Poisson's ratio, cohesion, and internal friction angle parameters of the slurry at time point t3 after time error correction are input.

[0037] (4) When the density value is in stage 4, that is, the density reaches ρ t4 After that, the slurry has been cured, and the strength, stiffness, elastic modulus, porosity, Poisson's ratio, cohesion, and internal friction angle parameters of the slurry at time point t4 after the time error correction are input.

[0038] After setting the parameters, grouting simulation is performed in the software. The slurry is injected into the fractured rock mass through the grouting holes, so that the slurry flows in the fractures of the fractured rock mass. Geotechnical engineering numerical calculations are performed to complete the connection calculation of the solid-liquid state change of the material in the numerical calculation.

[0039] After the entire grouting simulation process is completed, the simulation results are compared with the laboratory test results to verify the reliability of the method. For example, for the deformation of a fixed rock mass under study, the final deformation results of the grouting simulation and the laboratory test are compared. If the comparison error is large, the model parameters are checked and adjusted until the error is within the allowable error range. If the comparison error is small, it indicates that the simulation method is accurate and reliable.

[0040] Example 2 This embodiment provides a rock grouting simulation system based on solid-liquid connection, including: The model building module is configured to obtain the relationship between the density of the grouting slurry and time during the solidification process, and to establish an evolution model of the slurry density and time; The slurry property acquisition module is configured to divide the solidification process of the slurry to be grouted into multiple stages and respectively acquire the physical properties of each stage of the solidification process of the slurry to be grouted; The rock grouting simulation module is configured to change the parameters corresponding to the time in the rock grouting simulation process based on the obtained slurry density and time evolution model and the physical properties of each stage in the solidification process of the slurry to be grouting, so as to perform rock grouting simulation.

[0041] It should be noted here that the various modules in this embodiment correspond one-to-one to the steps of the method in Example 1, and the specific implementation process is the same, which will not be repeated here.

[0042] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A rock grouting simulation method based on solid-liquid connection, characterized in that: include: Obtain the relationship between the density and time of the grouting slurry during its solidification process, and establish a slurry density and time evolution model; The solidification process of the grouting slurry to be injected is divided into multiple stages, and the physical properties of each stage of the solidification process of the grouting slurry to be injected are respectively obtained; Based on the obtained evolution model of slurry density and time, and the physical properties of each stage in the solidification process of the slurry to be grouting, the parameters corresponding to the time in the rock grouting simulation process are changed to perform rock grouting simulation.

2. A rock grouting simulation method based on solid-liquid connection as claimed in claim 1, characterized in that: The evolution model of the slurry density and time is obtained by fitting the following equation: ； Where ρ represents the slurry density, t represents the time, a1, a2, a3, ..., a n are the constant parameters of the fitting.

3. A rock mass grouting simulation method based on solid-liquid connection as claimed in claim 1, characterized in that: The solidification process of the grouting slurry is divided into four stages according to the starting time of the hydration reaction, the initial setting time, the final setting time, and the time to complete the curing under standard conditions.

4. A rock grouting simulation method based on solid-liquid connection as claimed in claim 3, characterized in that: When the slurry density is between the density corresponding to the starting time of the hydration reaction and the density corresponding to the initial setting time, the slurry to be injected is in stage 1; the slurry in stage 1 is liquid, and the physical properties of the slurry in stage 1 are obtained based on a mathematical model of the correlation between the first physical parameter of the slurry and time.

5. A rock mass grouting simulation method based on solid-liquid connection as claimed in claim 4, characterized in that: The first physical parameters include fluidity, permeability, flow rate, cohesion, and bulk modulus of the slurry in liquid state. The mathematical model of the correlation between the first physical parameter and time is obtained by fitting according to the changing relationship between the fluidity, permeability, flow rate, cohesion, and bulk modulus of the slurry with time during laboratory tests.

6. A rock mass grouting simulation method based on solid-liquid connection as claimed in claim 5, characterized in that: It also includes obtaining the changing relationship of the first physical parameter with the test time and the simulation time respectively according to the mathematical model of the correlation between the first physical parameter and time and the corresponding relationship between the first physical parameter and time in the simulation, and performing time error correction on the mathematical model of the correlation between the first physical parameter and time.

7. A rock mass grouting simulation method based on solid-liquid connection as claimed in claim 3, characterized in that: When the density of the slurry is between the density corresponding to the initial setting time and the density corresponding to the final setting time, the slurry to be grouted is in stage 2; the slurry in stage 2 is solid, and the physical properties of the slurry in stage 2 are determined according to the second physical parameter of the slurry at the initial setting time; and / or, When the density of the slurry is between the density corresponding to the final setting time and the density corresponding to the time of completion of standard condition curing, the slurry to be grouted is in stage 3; the slurry in stage 3 is solid, and the physical properties of the slurry in stage 3 are determined according to the second physical parameter of the slurry at the final setting time; and / or, When the slurry density reaches the density corresponding to the time when standard conditions curing is completed, the slurry to be injected is in stage 4; the slurry in stage 4 is solid, and the physical properties of the slurry in stage 4 are determined according to the second physical parameter of the slurry at the time when standard conditions curing is completed.

8. A rock mass grouting simulation method based on solid-liquid connection as claimed in claim 4, characterized in that: According to the slurry density in the rock mass grouting simulation process, the stage of the grouting slurry is judged, and the slurry parameters are set according to the stage of the grouting slurry.

9. A rock mass grouting simulation method based on solid-liquid connection as claimed in claim 8, characterized in that: If the slurry to be injected is in stage 1, the grouting simulation parameters are set according to the obtained mathematical model of the correlation between the first physical parameter of the slurry and time.

10. A rock grouting simulation system based on solid-liquid connection, characterized in that: include: The model building module is configured to obtain the relationship between the density and time of the grouting slurry during the solidification process, and to establish an evolution model of the slurry density and time; The slurry property acquisition module is configured to divide the solidification process of the slurry to be grouted into multiple stages, and respectively acquire the physical properties of each stage of the solidification process of the slurry to be grouted; The rock grouting simulation module is configured to change the parameters corresponding to the time in the rock grouting simulation process based on the obtained evolution model of slurry density and time, and the physical properties of each stage in the solidification process of the slurry to be grouting, so as to perform rock grouting simulation.

Images