A rock grouting simulation method and system based on solid-liquid connection

Abstract

The present invention provides a rock grouting simulation method and system based on solid-liquid connection, which relates to the technical field of rock grouting simulation. The method comprises: obtaining the relationship between the density change over time during the solidification process of the grouting slurry to be injected, and establishing an evolution model of the slurry density and time; dividing the solidification process of the grouting slurry to be injected into multiple stages, and respectively obtaining the physical properties of each stage during the solidification process of the grouting slurry to be injected; based on the obtained evolution model of the slurry density and time, and the physical properties of each stage during the solidification process of the grouting slurry to be injected, changing the parameters corresponding to the time during the rock grouting simulation process, and performing rock grouting simulation. The present invention can improve the accuracy of the simulation calculation process of geotechnical engineering such as rock grouting.

Description

Technical Field

[0001] The 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] In the numerical calculation research of geotechnical engineering, we often have to face complex geological conditions with liquid and solid mixing. Taking grouting operation as an example, the rock mass in actual engineering is not a complete rock, but a rock mass with a complex network of crisscrossing cracks. The existence of these cracks reduces the stability of the rock mass. Therefore, grouting operation is required to fill the cracks with slurry, thereby reinforcing 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 substance is converted into solid substance, and thus it is difficult to determine the diffusion range of the liquid substance. In response to this, the prior art 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 that affect the calculation results due to the entire process of changes in the material morphology. Summary of the invention

[0004] In order to solve the deficiencies of the prior art, the purpose of the present invention is 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] In order to achieve the above object, according to some embodiments, a first aspect of the present invention provides a rock grouting simulation method based on solid-liquid connection, comprising:

[0006] 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;

[0007] 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;

[0008] 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.

[0009] A second aspect of the present invention provides a rock grouting simulation system based on solid-liquid connection, comprising:

[0010] 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;

[0011] 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;

[0012] 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.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 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 material form of slurry, and through a combination of experiments and simulation calculations, the relationship between the density of the slurry and time in the whole process of solidification from liquid to solid is obtained through a slurry migration experiment, and an evolution model of slurry density and time is established, so as to guide the change of slurry parameters at different time points in the rock grouting simulation process, and realize the connection calculation when the solid-liquid form changes during the simulation process. At the same time, compared with the slurry viscosity, the slurry density has a 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.

[0015] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings in the specification, 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.

[0017] Figure 1 Schematic diagram of the process of the method in Embodiment 1 of the present invention;

[0018] Figure 2 It is a 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.

[0019] Among them, 1. slurry; 2. grouting hole; 3. fractured rock mass; 4. fracture. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0021] Embodiment 1

[0022] Embodiment 1 of the present invention provides a rock mass grouting simulation method based on solid-liquid connection, such as Figure 1-Figure 2 As shown, including:

[0023] S1. Obtain the relationship between the density and time of the grouting slurry during the solidification process, and establish an evolution model of the slurry density and time;

[0024] 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;

[0025] S3. 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.

[0026] 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, the slurry 1 used is slurry A, and the ratio of each material is fixed; the geotechnical numerical calculation software used is software B, and numerical calculation and simulation of the rock grouting process can be realized in software B. In some embodiments, slurry 1 is a cement slurry commonly used in geotechnical 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. Fissures 4 are complex crisscrossing fracture network channels existing in the fractured rock mass 3. The slurry 1 is injected into the fracture 4 of the fractured rock mass 3 from the grouting hole 2, and diffuses in the fracture 4, so that the slurry 1 gradually fills all the fractures 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.

[0027] During the slurry solidification process, in order to accurately reflect the diffusion, sealing and reinforcement effects of the slurry, numerical calculation is often used to describe the grouting process. However, in the process of the slurry changing from liquid to solid, its physical and mechanical parameters will change, which makes the numerical calculation process complicated. Moreover, it can only be calculated in stages according to the states before and after solidification, and the two-stage calculation process is difficult to connect.

[0028] In this regard, this embodiment proposes to use slurry density as an indicator to judge the morphology of slurry materials, combine experiments with numerical calculations, first obtain the law of change in the slurry solidification process through laboratory slurry migration tests, establish a slurry density and time evolution model to obtain the parameters required for numerical calculations, and then determine the relevant parameters required for numerical calculations at different time points based on the slurry density and time evolution model, and input them into the B software used for numerical calculations for calculation. The entire process of solidification of slurry A 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, so that the final position of the flow of liquid slurry A can be determined, that is, the final diffusion range of liquid slurry A is clarified. Measuring density by mass volume method can avoid the error caused by friction generated by rotor rotation in the acquisition process of data such as slurry viscosity and shear rheology model in the solution based on slurry viscosity. When instruments such as rotational viscometers and rotational rheometers test the viscosity and shear rheology of slurries, there will be a disc rotor or cylindrical rotor that can rotate in the slurry. When this rotor rotates in the slurry, friction will be 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 will not introduce errors caused by measurement, thereby improving the accuracy of the simulation calculation. In addition, in the calculation process of this embodiment, the entire process of the slurry solidifying from liquid to solid is calculated, which reduces the error caused by ignoring the process of liquid solidification to solid in previous solutions on the calculation results.

[0029] In step S1, by installing a density measurement device based on the mass volume method in the slurry migration test equipment, the density change data of the slurry from liquid to solid in the migration test is collected over time, so as to establish a slurry density and time evolution model.

[0030] 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 location where the measuring device is installed in real time according to the ratio of the slurry mass at the location where the measuring device is installed and the pipeline volume. The time interval for each calculation is 1 second.

[0031] In the slurry migration test, the density data is obtained in seconds, and the slurry density data per second is finally obtained, that is, the change data of slurry density over time during the test. The evolution model of slurry density and time is established based on the obtained data. For the obtained data, statistical correlation methods are used to analyze the rules and trends, judge and find a mathematical model that is more consistent with the data for fitting.

[0032] The established slurry density and time evolution model is a mathematical model of slurry density variation over time. In this embodiment, based on the analysis results of the slurry density variation over time data, it is assumed that the data conforms to the mathematical model of the following equation:

[0033] ;

[0034] Where ρ represents the slurry density (in kilograms per cubic meter, kg / m 3 ), t represents time (in seconds, s), the value of t is taken as zero at the start time of the test, a1, a2, a3, ..., a n are the constant parameters of the fitting.

[0035] According to the obtained data of slurry density change over time, the model is fitted to solve all constant parameters. However, the model is not unique, and the optimal solution is the mathematical model that can contain the largest range of density change data over time. If the obtained mathematical model contains less slurry density change data per second, other mathematical model forms (such as exponential function, logarithmic function, Fisher distribution function and other mathematical models) can also be used for fitting until the optimal solution is found.

[0036] 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:

[0037] (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.

[0038] (2) Initial setting time t2: The slurry gradually loses fluidity and plasticity over time. The initial setting time obtained in the laboratory shall prevail.

[0039] (3) Final setting time t3: After initial setting, the cement slurry gradually hardens and its strength gradually increases until it evolves into a hard solid substance. The final setting time obtained in the laboratory shall prevail.

[0040] (4) Time t4 for completion of standard 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.

[0041] The slurry density at four time points was obtained in the laboratory: ρ t1 , ρ t2 , ρ t3 , ρ t4 .

[0042] Based on the density change, it is divided into four stages according to the above four time points:

[0043] Stage 1: Slurry density is at ρ t1 ~ρ t2 When the temperature is within the range, the slurry is in liquid state at this stage and still has fluidity and plasticity;

[0044] 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;

[0045] 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;

[0046] Stage 4: Slurry density reaches ρ t4 During the subsequent testing time, the slurry in this stage has been completely solidified and has developed structural strength.

[0047] For stage 1, laboratory tests were conducted on the slurry, with data recording intervals of every second. The same method as in step S1 was used to obtain the evolution model of slurry density and time, and mathematical models of the relationship between the fluidity, permeability, flow rate, cohesion, and bulk modulus of the slurry in liquid state (liquid-related parameters obtained from laboratory studies can be adjusted according to the needs of different numerical simulation software) and time were obtained. For the convenience of distinction, the fluidity, permeability, flow rate, cohesion, and bulk modulus of the slurry in liquid state are referred to as the first physical parameters below.

[0048] For stage 2, 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 t2 (the parameters obtained from laboratory studies can be adjusted according to the needs of different numerical simulation software). For the convenience of distinction, the strength, stiffness, elastic modulus, porosity, Poisson's ratio, cohesion, and internal friction angle parameters of the slurry in the solid state are referred to as the second physical parameters below.

[0049] For stage 3, laboratory tests 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 t3 (the parameters obtained from laboratory studies can be adjusted according to the needs of different numerical simulation software).

[0050] For stage 4, laboratory tests 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).

[0051] In step S3, first, in software B, according to the engineering needs, the grouting pressure, surrounding rock pressure in all directions, and the strength, stiffness, elastic modulus, porosity, Poisson's ratio, cohesion, and internal friction angle parameters of the fractured rock mass to be simulated for grouting are input. Then, according to the evolution model of slurry density and time obtained in step S1 and the physical properties of each stage in the solidification process of the slurry to be grouted obtained in step S2, the parameters of the slurry in the grouting simulation process are changed, and then the rock mass grouting simulation is performed.

[0052] The rock mass 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 test, and it is not possible to correspond to each 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 test and 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 is determined according to the test instrument selected by the laboratory, but its numerical range remains unchanged), the time when the slurry fluidity reaches x in the test 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 value and the n value have corresponding changes. Based on the same method as the evolution model of slurry density and time established in step S1, the mathematical model of the change of x with m within the numerical range is fitted, recorded as equation M, and the mathematical model of the change of x with n within the numerical range is recorded as equation N. Since the numerical range of x remains unchanged, M=N can be set to obtain the relationship between m and n, and then the mathematical model of the correlation between fluidity and time after time error correction is obtained. The time error of other parameters (permeability, flow rate, cohesion, bulk modulus of slurry in liquid state, strength, stiffness, elastic modulus, porosity, Poisson's ratio, cohesion, internal friction angle of slurry in solid state, and slurry density) is also corrected in this way.

[0053] The mathematical model of the slurry density change with time obtained in step S1 is used as the density data of the slurry in the entire grouting simulation process after time error correction, and is input into the B software for simulation (the software is input through programming methods such as Matlab program and Fish language, the same below). In the grouting simulation process, the density change is used as the judgment basis, and the parameters of the grouting simulation are set respectively:

[0054] (1) When the density value is in stage 1, that is, the density is in the range ρ t1 ~ρ t2At 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.

[0055] (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 the time error correction are obtained.

[0056] (3) When the density value is in stage 3, that is, the density is in the range ρ t3 ~ρ t4 At 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.

[0057] (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.

[0058] After setting the parameters, the 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. The geotechnical engineering numerical calculation is performed to complete the connection calculation of the solid-liquid morphology change of the material in the numerical calculation.

[0059] When 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 in the 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 they are within the allowable error range; if the comparison error is small, it means that the simulation method is accurate and reliable.

[0060] Embodiment 2

[0061] This embodiment provides a rock grouting simulation system based on solid-liquid connection, including:

[0062] 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;

[0063] 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;

[0064] 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.

[0065] 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.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope 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; According to the starting time of the hydration reaction, the initial setting time, the final setting time, and the time for completing the standard condition curing, the solidification process of the slurry to be grouted is divided into four stages, and the physical properties of each stage of the solidification process of the slurry to be grouted are obtained respectively; 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 grouted is in stage 1; the slurry in stage 1 is liquid, and the physical properties of the slurry in stage 1 are obtained according to the mathematical model of the correlation between the first physical parameter of the slurry and time; the first physical parameter includes the fluidity, permeability, flow rate, cohesion, and bulk modulus of the slurry in the liquid state, and the mathematical model of the correlation between the first physical parameter and time is fitted according to the relationship between the fluidity, permeability, flow rate, cohesion, and bulk modulus of the slurry changing with time during the laboratory test; 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, the relationship between the first physical parameter and the test time and the simulation time is obtained respectively, and the mathematical model of the correlation between the first physical parameter and time is corrected for time error; 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; according to the slurry density in the rock 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; if the slurry to be grouting 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.

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: ； in, ρ represents the slurry density, t Represents time, a 1. a 2. a 3. ... 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: 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.

4. 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 four stages according to the starting time of the hydration reaction, the initial setting time, the final setting time, and the time for completing the standard condition curing, and respectively obtain the physical properties of each stage in the solidification process of the slurry to be grouted; 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 grouted is in stage 1; the slurry in stage 1 is liquid, and the physical properties of the slurry in stage 1 are obtained according to the mathematical model of the correlation between the first physical parameter of the slurry and time; the first physical parameter includes the slurry The mathematical model of the correlation between the fluidity, permeability, flow rate, cohesion, bulk modulus of the liquid in the liquid state and the first physical parameter and time is obtained by fitting the relationship between the fluidity, permeability, flow rate, cohesion and bulk modulus of the slurry and time during the laboratory test; the relationship between the first physical parameter and the test time and the simulation time is obtained 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 the mathematical model of the correlation between the first physical parameter and time is corrected for time error; 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 grouted, and perform rock grouting simulation; according to the slurry density in the rock grouting simulation process, judge the stage of the grouting slurry, and set the slurry parameters according to the stage of the grouting slurry; if the slurry to be grouted is in stage 1, set the grouting simulation parameters according to the obtained mathematical model of the correlation between the first physical parameter of the slurry and time.

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