Polyurethane permeation grouting diffusion simulation method, device, equipment and medium

Abstract

The invention discloses a polyurethane permeation grouting diffusion simulation method, device and equipment and a medium, and the method comprises the steps: building a geometric model of permeation grouting diffusion of polyurethane in a to-be-injected porous medium according to the physical attribute data of the to-be-injected porous medium; establishing a physical field of the geometric model by adopting a Richardz equation and a porous medium dilute material transfer equation, and adjusting the geometric model according to material attribute parameters of the geometric model obtained by the physical field; setting a boundary condition and an initial value of the adjusted geometric model, and performing grid division on the adjusted geometric model based on a local refinement method to obtain a permeation grouting diffusion simulation model; and solving the permeation grouting diffusion simulation model according to the transient solver, and completing simulation of permeation grouting diffusion of polyurethane in the porous medium. According to the method provided by the invention, the modeling accuracy of the slurry diffusion process is improved.

Description

Technical Field

[0001] The present application relates to the field of geotechnical engineering, and in particular to a polyurethane penetration grouting diffusion simulation method, device, equipment and medium. Background Art

[0002] Grouting has long been the most effective means of preventing and controlling sudden water in underground projects. Existing grouting methods can be divided into penetration grouting, fissure grouting, splitting grouting, etc. according to the diffusion form of the slurry in the injected medium. Among them, penetration grouting refers to the penetration form of slurry in porous media, and the slurry only seeps in the pores. Different from the construction method of traditional cement-based grouting materials, chemical grouting materials need to be mixed evenly by a static mixer. When the slurry is injected into the formation, the viscosity begins to change. The viscosity of the slurry injected first has been increasing for a period of time, while the viscosity of the slurry just injected has just begun to increase, which results in different slurry viscosities at different locations. Therefore, the temporal and spatial variation characteristics of the slurry viscosity need to be considered.

[0003] However, the existing technology is difficult to accurately reflect the complex physical structure and changes when constructing the infiltration grouting diffusion model, which leads to deviations between the simulation results and the actual situation. Summary of the invention

[0004] The present application aims to provide a polyurethane penetration grouting diffusion simulation method, device, equipment and medium to improve the accuracy of slurry diffusion process modeling.

[0005] In order to solve the above technical problems, the present application provides a polyurethane penetration grouting diffusion simulation method, comprising the following steps:

[0006] According to the physical property data of the porous medium to be injected, a geometric model of the penetration grouting and diffusion of polyurethane in the porous medium to be injected is constructed;

[0007] The physical field of the geometric model is established by using the Richards equation and the porous medium dilute species transport equation, and the geometric model is adjusted according to the material property parameters of the geometric model obtained by the physical field, wherein the physical field reflects the influence of the material properties of the polyurethane on the seepage and diffusion process;

[0008] Setting boundary conditions and initial values ​​of the adjusted geometric model, and meshing the adjusted geometric model based on a local refinement method to obtain a permeation grouting diffusion simulation model;

[0009] The penetration grouting diffusion simulation model is solved according to the transient solver to complete the simulation of the penetration grouting diffusion of the polyurethane in the porous medium to be injected.

[0010] As one preferred solution, adjusting the geometric model according to the material property parameters of the geometric model obtained by the physical field includes:

[0011] Construct a diffusion model based on Newtonian fluid rheological equation and seepage motion equation;

[0012] Obtaining the permeability function of the polyurethane in the porous medium to be injected in stages according to the diffusion model;

[0013] Obtaining the dynamic viscosity of the polyurethane during the infiltration grouting diffusion process in the porous medium to be injected based on rheological experiments;

[0014] The geometric model is adjusted by using the permeability function and the dynamic viscosity as material property parameters of the geometric model.

[0015] As one preferred solution, the permeability function is expressed as:

[0016]

[0017] Where pwl(t) represents permeability, φ represents porosity, d represents pore diameter, t represents penetration time, and t 1 Indicates the time when flow resistance disappears, t 2 represents the slurry solidification time, δ represents the porosity, ρ represents the slurry density, R represents the radius of the porous medium, is the integral median value of the dynamic viscosity and penetration time function, φ 0 and K 0 is the porosity under initial effective stress conditions.

[0018] As one preferred solution, the dynamic viscosity is expressed as:

[0019] μ(t)=C 1 ·e kt +μ 0 0≤t≤t 2 ,

[0020] Where, μ(t) is the function of dynamic viscosity and time, μ 0 is the initial viscosity of the slurry, t is the time, t 2 is the slurry flow-solid phase change time, k is the time-varying coefficient, C 1 is a constant.

[0021] As one of the preferred solutions, the geometric model of the penetration grouting diffusion of polyurethane in the porous medium to be injected is constructed according to the physical property data of the porous medium to be injected, including:

[0022] Based on the cross-section method, the diffusion process of the polyurethane in the porous medium to be injected is two-dimensionalized to obtain a two-dimensional model of the infiltration grouting;

[0023] Determining geometric parameters of the two-dimensional model according to physical property data of the porous medium to be injected;

[0024] A geometric model of the polyurethane in the porous medium to be injected is constructed based on an infinite source domain method and the geometric parameters.

[0025] As one of the preferred solutions, the adjusted geometric model is meshed based on the local refinement method to obtain a permeation grouting diffusion simulation model, including:

[0026] Performing preliminary meshing on the adjusted geometric model to obtain a sparse mesh;

[0027] According to the simulation requirements of the geometric model, identifying the key areas in the sparse grid, the key areas at least including the grouting pipe area and the inner area of ​​the porous medium;

[0028] The key area is meshed again based on a local refinement method to obtain a penetration grouting diffusion simulation model.

[0029] As one of the preferred solutions, solving the penetration grouting diffusion simulation model according to a transient solver to complete the simulation of the penetration grouting diffusion of the polyurethane in the porous medium to be injected includes:

[0030] According to the rheological equation of Newtonian fluid and the seepage motion equation, a partial differential equation corresponding to the infiltration grouting diffusion process of the polyurethane in the porous medium to be injected is set;

[0031] Using an implicit Euler backward difference method to discretize the time term in the partial differential equation to obtain a discretized partial differential equation;

[0032] The discretized partial differential equation is input into a pre-built transient solver for solving, and the penetration grouting diffusion process of the polyurethane in the porous medium is simulated by adjusting the number of iterations and the time step of the transient solver.

[0033] Another embodiment of the present application provides a polyurethane penetration grouting diffusion simulation device, comprising:

[0034] A construction module, for constructing a geometric model of the penetration grouting and diffusion of polyurethane in the porous medium to be injected according to the physical property data of the porous medium to be injected;

[0035] An assignment module, used for establishing a physical field of the geometric model by using the Richards equation and the porous medium dilute species transport equation, and adjusting the geometric model according to the material property parameters of the geometric model obtained by the physical field, wherein the physical field reflects the influence of the material properties of the polyurethane on the seepage and diffusion process;

[0036] A partitioning module, used for setting boundary conditions and initial values ​​of the adjusted geometric model, and performing mesh partitioning on the adjusted geometric model based on a local refinement method to obtain a permeation grouting diffusion simulation model;

[0037] The calculation module is used to solve the penetration grouting diffusion simulation model according to the transient solver to complete the simulation of the penetration grouting diffusion of the polyurethane in the porous medium to be injected.

[0038] Another embodiment of the present application provides a computer device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, the polyurethane penetration grouting diffusion simulation method as described above is implemented.

[0039] Yet another embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, wherein when the device where the computer-readable storage medium is located executes the computer program, the polyurethane infiltration grouting diffusion simulation method as described above is implemented.

[0040] Compared with the prior art, the beneficial effects of the embodiments of the present application are at least one of the following:

[0041] (1) The present application constructs a geometric model based on the actual physical structure and properties of the porous medium, which can more realistically reflect the complexity and irregularity of the porous medium, thereby improving the accuracy of the simulation; the physical field is established using the Richards equation and the porous medium dilute species transport equation. These two equations respectively describe the unsaturated seepage and material transfer processes of the fluid in the porous medium, which can more accurately reflect the seepage and diffusion behavior of polyurethane in the porous medium.

[0042] (2) This application can evaluate the permeability, diffusion and other properties of materials by simulating the seepage and diffusion behavior of different polyurethane materials in porous media, providing a basis for material selection and design.

[0043] (3) Through numerical simulation, this application can quickly evaluate the advantages and disadvantages of different grouting schemes or material schemes and improve decision-making efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic flow chart of a polyurethane penetration grouting diffusion simulation method in one embodiment of the present application;

[0045] Figure 2 is a schematic diagram of mesh division of a grouting geometric model in one embodiment of the present application;

[0046] Figure 3 It is a structural schematic diagram of a polyurethane penetration grouting diffusion simulation device in one embodiment of the present application;

[0047] Figure 4 It is a schematic diagram of a polyurethane penetration grouting diffusion simulation device in one embodiment of the present application. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. The purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] In the description of this application, the terms "first", "second", "third", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of the feature. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0050] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. The terms "vertical", "horizontal", "left", "right", "upper", "lower" and similar expressions used in this article are only for illustrative purposes, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. The term "and / or" used in this article includes any and all combinations of one or more related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0051] In the description of this application, it should be noted that, unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by those skilled in the art. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0052] An embodiment of the present application provides a polyurethane penetration grouting diffusion simulation method. For details, see Figure 1 , Figure 1 The figure shows a flow chart of a polyurethane penetration grouting diffusion simulation method provided in one embodiment of the present application. The method comprises steps S1 to S4:

[0053] S1. Constructing a geometric model of polyurethane penetration grouting diffusion in the porous medium to be injected according to the physical property data of the porous medium to be injected;

[0054] S2. Using the Richards equation and the porous medium dilute species transport equation to establish the physical field of the geometric model, and adjusting the geometric model according to the material property parameters of the geometric model obtained by the physical field, wherein the physical field reflects the influence of the material properties of the polyurethane on the seepage and diffusion process;

[0055] S3, setting boundary conditions and initial values ​​of the adjusted geometric model, and meshing the adjusted geometric model based on a local refinement method to obtain a permeation grouting diffusion simulation model;

[0056] S4. Solving the penetration grouting diffusion simulation model according to the transient solver to complete the simulation of the penetration grouting diffusion of the polyurethane in the porous medium to be injected.

[0057] It should be noted that in the prior art, the influence of gravity and the spatiotemporal variation of the slurry viscosity are not considered when the slurry penetrates the porous medium, and the heterogeneity of the porous medium seepage channel itself is also ignored. Since the slurry has a time-varying viscosity, as the slurry diffuses during the grouting process, solidified particles will gradually form and fill the pores of the porous medium, reducing its original permeability. In view of the above shortcomings, the present application provides a method that is more in line with the practice of grouting engineering. In addition, a permeation grouting modeling method is provided.

[0058] Assuming that the porous medium is isotropic, the penetration and diffusion process of the slurry can be intuitively understood through the formation section, so the grouting model can be simplified to a two-dimensional model in an axisymmetric form. The vertical axis on the left is the symmetry axis. An infinite element domain is added to the right and bottom of the section with a thickness of 0.5*R1 and a cylindrical type so that the polyurethane can freely leave the soil column and reduce the impact of the artificial boundary on the target area. The established geometric model is a spherical diffusion model of porous medium polyurethane penetration grouting. Among them, the porous medium is set as a region with a radius of R1=1m and a height of H1=2m, and the radius of the grouting pipe is r1=5cm and the height is h1=0.6m.

[0059] Preferably, in one embodiment of the present invention, constructing a geometric model of the penetration grouting diffusion of polyurethane in the porous medium to be injected according to the physical property data of the porous medium to be injected comprises:

[0060] Based on the cross-section method, the diffusion process of the polyurethane in the porous medium to be injected is two-dimensionalized to obtain a two-dimensional model of the infiltration grouting;

[0061] Determining geometric parameters of the two-dimensional model according to physical property data of the porous medium to be injected;

[0062] A geometric model of the polyurethane in the porous medium to be injected is constructed based on an infinite source domain method and the geometric parameters.

[0063] Specifically, the infinite source domain method is a mathematical model used to simulate the flow and diffusion of fluids in porous media. This method assumes that the fluid source is infinite and the flow and diffusion of fluids in porous media are continuous. Using the infinite source domain method and the determined geometric parameters, a geometric model of polyurethane in porous media is constructed. In the model, the process of polyurethane grouting liquid gradually diffusing and penetrating in porous media starting from the grouting port should be accurately reflected.

[0064] Polyurethane permeates and diffuses in unsaturated porous media, and the Richards equation module and the porous media dilute species transport module are used to simulate its permeation and diffusion process. The pressure field in the porous medium during the permeation process can be expressed as:

[0065]

[0066] Where p is the pore water pressure (Pa), S e is the effective saturation (-), S p is the water storage coefficient (1 / Pa), C m is the water content (1 / m), ρ is the fluid density (kg / m 3 ), g is the acceleration due to gravity (m / s 2 ), is the Hamiltonian operator, u is the fluid velocity, κs is the hydraulic conductivity (m 2 ), μ is the fluid dynamic viscosity (Pa·s), κ r is the relative permeability (-), Q m is the fluid source or sink term (kg / (m 3 ·s)).

[0067] The slurry concentration field during the diffusion process can be expressed as:

[0068]

[0069] Where θ is the volumetric water content (m 3 / m 3 ), c i is the concentration of each substance in the solution (mol / m 3 ), ρ is the solution density (kg / m 3 ), c p,i is the adsorption concentration of soil particles (mol / kg), u is the fluid velocity (m / s), D D,i is the diffusion tensor (m 2 / s), D e,i is the effective diffusion coefficient (m 2 / s), R i is the physicochemical reaction term (mol / (m 2 ·s)), S i is the source and sink term (mol / (m 2 ·s)).

[0070] Preferably, in an embodiment of the present invention, adjusting the geometric model according to the material property parameters of the geometric model obtained by the physical field comprises:

[0071] Construct a diffusion model based on Newtonian fluid rheological equation and seepage motion equation;

[0072] Obtaining the permeability function of the polyurethane in the porous medium to be injected in stages according to the diffusion model;

[0073] Obtaining the dynamic viscosity of the polyurethane during the infiltration grouting diffusion process in the porous medium to be injected based on rheological experiments;

[0074] The geometric model is adjusted by using the permeability function and the dynamic viscosity as material property parameters of the geometric model.

[0075] The material properties and parameters to be assigned are determined according to the physical field, as described in Tables 1 and 2.

[0076] Table 1 Diffusion model user definition

[0077]

[0078] Table 2 Polyurethane and porous medium material parameters

[0079]

[0080] Specifically, it is assumed that the following conditions are met during the penetration and diffusion of polyurethane in porous media:

[0081] 1) Use static pressure grouting, ignoring the pressure loss from the grouting pipe to the pipe mouth and the velocity loss during the diffusion process;

[0082] 2) The slurry is an incompressible, isotropic Newtonian fluid that satisfies Darcy’s law during diffusion;

[0083] 3) During the entire infiltration process, the slurry infiltrates in a laminar flow and does not mix with the groundwater, which is a complete displacement process;

[0084] 4) The porous medium does not move during the slurry penetration, displacement and solidification process;

[0085] 5) The injected porous medium is a uniform and isotropic medium.

[0086] The basic rheological equation of Newtonian fluid can be expressed as

[0087] τ=μ·γ (1)

[0088] Among them, τ is the shear force, that is, the internal friction force per unit area of ​​the slurry (Pa), μ is the dynamic viscosity (mPa·s), and γ = -dv / dr is the shear rate (s -1 ), v and r are the seepage velocity of the fluid in the pore channel and the geometric distance perpendicular to the flow direction of the slurry, respectively. In actual engineering, the slurry will gradually solidify when reacting with water, and its viscosity will change with time. The time-varying law of the viscosity is usually expressed in the form of an exponential function, that is,

[0089] μ(t)=C 1 ·e kt +μ 0 0≤t≤t 2 (2)

[0090] Where, μ(t) is the function of dynamic viscosity and time (mPa·s), which can be measured by rheometer test, μ 0 is the initial viscosity of the slurry, t is the time (s), t 2 is the slurry flow-solid phase change time (s), k is the time-varying coefficient, C 1 is a constant. For the convenience of calculation, the viscosity integral median is used to calculate the slurry diffusion radius considering the time-varying viscosity, that is,

[0091]

[0092] For the laminar flow state of Newtonian fluid in porous media, a microelement is taken on the flow path with the tube axis as the symmetry axis for analysis. Assume that the radius of the circular tube is r 0 , micro element radius r>r 0 , the length is dl. The pressures on the left and right sections of the microelement are p and p+dp respectively, and the shear stress on the upper and lower surfaces of the microelement is τ. Considering gravity, the equilibrium condition of the force on the microelement is

[0093]

[0094] Among them, θ is the angle between the slurry diffusion direction and the grouting pipe. When the diffusion direction is upward to the horizontal plane, the angle is positive; when the diffusion direction is downward to the horizontal plane, the angle is negative.

[0095]

[0096] Substituting (5) into (1), we obtain

[0097]

[0098] Now integrate (6) and set the boundary condition r = r 0 Substituting v=0 into

[0099]

[0100] Therefore, when the slurry moves in laminar flow in a single circular tube, the total flow rate in the tube is

[0101]

[0102] Assume that there is N in the porous medium i The radius is r i The total flow rate of slurry in the porous medium is

[0103]

[0104] In the actual porous media pores, the capillary tubes are random and non-uniform. The tortuosity can be used to characterize the tortuosity effect of fluid particle movement and diffusion, and its definition is as follows:

[0105]

[0106] Among them, L t is the actual length of the slurry flowing through the porous medium channel, L 0 is the diffusion distance between the grouting hole and the slurry front, and χ is the physical tortuosity. Therefore, the total slurry flow rate in the porous medium can be transformed into

[0107]

[0108] Based on the Bruggeman model, the relationship between physical tortuosity and geometric tortuosity is given as follows:

[0109] χ=χ g φ 0.1 (12)

[0110] Among them, χ g is the geometric tortuosity, which can be determined by image analysis combined with the pore centroid method. Porosity can be expressed as

[0111]

[0112] Where A = 4πR 2 is the diffusion area of ​​the porous medium. Since the seepage velocity V = Q / A, then

[0113]

[0114] The effective permeability of the formation is

[0115]

[0116] The Newtonian fluid seepage motion equation is obtained

[0117]

[0118] The specific permeability function and dynamic viscosity are obtained based on the Newtonian fluid rheological equation and seepage motion equation combined with rheological experiments.

[0119] Preferably, in one embodiment of the present invention, the permeability function is expressed as:

[0120]

[0121] Where pwl(t) represents permeability, φ represents porosity, d represents pore diameter, t represents penetration time, and t 1 Indicates the time when flow resistance disappears, t 2 represents the slurry solidification time, δ represents the porosity, ρ represents the slurry density, R represents the radius of the porous medium, is the integral median value of the dynamic viscosity and penetration time function, φ 0 and K 0 is the porosity under initial effective stress conditions.

[0122] Preferably, in one embodiment of the present invention, the dynamic viscosity is expressed as:

[0123] μ(t)=C 1 ·e kt +μ 0 0≤t≤t2 ,

[0124] Where, μ(t) is the function of dynamic viscosity and time, μ 0 is the initial viscosity of the slurry, t is the time, t 2 is the slurry flow-solid phase change time, k is the time-varying coefficient, C 1 is a constant.

[0125] Specifically, the dynamic viscosity is measured by rheological experiments as follows:

[0126] ant1(t)=32.51*exp(0.0027*t).

[0127] After setting the material property parameters, determine the boundary conditions and initial values. This application sets the pressure boundary conditions. Considering the influence of gravity, the initial pressure value is set to -(z+H1), the pressure head is set to rho0 / (1000[kg / m^2]*(-g_const)), the bottom and right infinite element domain boundaries are set to permeable layers, and the external head is -2m. Next, set the concentration boundary conditions. Set the initial concentration value to 0, the concentration to c0, and the outflow boundary to 0.

[0128] Preferably, in one embodiment of the present invention, the meshing of the adjusted geometric model based on the local refinement method to obtain the infiltration grouting diffusion simulation model includes:

[0129] Performing preliminary meshing on the adjusted geometric model to obtain a sparse mesh;

[0130] According to the simulation requirements of the geometric model, identifying the key areas in the sparse grid, the key areas at least including the grouting pipe area and the inner area of ​​the porous medium;

[0131] The key area is meshed again based on a local refinement method to obtain a penetration grouting diffusion simulation model.

[0132] For details, see Figure 2 , Figure 2 The figure shows a schematic diagram of the meshing of the grouting geometry model in one embodiment of the present application. The model is meshed by using user-controlled meshing, setting free quadrilateral meshing and local refinement. Local refinement performs secondary meshing encryption on the area near the grouting pipe, and sets the meshing encryption area range to r(0, 0.5*R1), z(-0.5*H1, 0) by specifying the border.

[0133] Preferably, in one embodiment of the present invention, solving the penetration grouting diffusion simulation model according to a transient solver to complete the simulation of the penetration grouting diffusion of the polyurethane in the porous medium to be injected includes:

[0134] According to the rheological equation of Newtonian fluid and the seepage motion equation, a partial differential equation corresponding to the infiltration grouting diffusion process of the polyurethane in the porous medium to be injected is set;

[0135] Using an implicit Euler backward difference method to discretize the time term in the partial differential equation to obtain a discretized partial differential equation;

[0136] The discretized partial differential equation is input into a pre-built transient solver for solving, and the penetration grouting diffusion process of the polyurethane in the porous medium is simulated by adjusting the number of iterations and the time step of the transient solver.

[0137] Specifically, a transient solver is used for calculation, with a calculation step of 5s and a calculation time of 3600s. It should be noted that in the simulation implementation process, by assigning values ​​to the coefficient-type partial differential equations built into the simulation software as needed, partial differential equations with various properties can be obtained. After assigning values ​​to the coefficients of the equations, numerical solutions can be used. The implicit Euler backward difference method is used to discretize the time term in the equation, and the nonlinear iterative modified damped Newton method is used to solve the equation.

[0138] Finally, the data is visualized to complete the penetration grouting diffusion process.

[0139] In addition, the present application also provides a method for determining the diffusion radius of spherical infiltration grouting of polyurethane infiltration grouting. In the early stage of grouting, the slurry is significantly affected by the flow resistance, and the permeability gradually increases; when the flow rate gradually stabilizes, the slurry is in a pure flow state or a plastic state, and its infiltration process can be regarded as diffusion with constant permeability; as the grouting process gradually advances, the rheological properties of the slurry gradually change from the fluid-solid phase change stage to the solid state, and a slurry solidification circle gradually forms at the diffusion front. Affected by the grouting pressure, the solidification circle gradually spreads in the porous medium, and the permeability in the porous medium gradually decreases until it reaches 0. Therefore, the present application divides the slurry diffusion in the infiltration process into three stages: infiltration diffusion, stable grouting, and phase change solidification.

[0140] 1) Osmosis and diffusion stage

[0141] In the grouting time t, the slurry diffusion radius is R, and the grouting volume is

[0142]

[0143] The required grouting volume within the grouting time t is equal to the grouting volume required for the grout to flow through the pores in the diffusion area during this period. The grouting volume can also be expressed as:

[0144] Q=VA·t (18)

[0145] Combining (16) and (17), the pressure gradient in the polyurethane penetration region is obtained as:

[0146]

[0147] The pressure decay outside the slurry penetration front is much smaller than that inside the slurry penetration front. It can be considered that the pressure outside the slurry penetration front is constant, and the pressure at the front position is continuous with the external pressure p=p 0 In the early stage of grouting, the permeability of the porous medium changes with the slurry flow rate due to the influence of fluid inertia. Iberall derived the expression of porous medium permeability based on the flow resistance model:

[0148]

[0149] Where Re is the Reynolds number, ρ is the slurry density, and δ is the initial pore diameter of the porous medium. Combining (17), (18), (20), and (21), the formation permeability can be expressed as

[0150]

[0151] Take the radius of the grouting pipe as r and consider the boundary condition of grouting pressure: when p = p 0 When L 0 = r; when p = p 1 When L 0 =R 1 Among them, p 1 and R 1 The grouting time is t 0 The pressure at the grouting point and the diffusion distance of the slurry are calculated by combining (19) and (22), substituting the boundary conditions, separating the variables and integrating them, and obtaining the diffusion control equation of the infiltration grouting considering the influence of permeability:

[0152]

[0153] Among them, p 0 It is the constant pressure outside the slurry penetration front.

[0154] 2) Stable grouting stage

[0155] As the infiltration grouting process gradually stabilizes, the slurry flow rate and the permeability K in the porous medium 2 =K 0 is a constant value.

[0156] Consider the grouting pressure boundary condition: when p = p 0 When L 0 = r; when p = p 2 When L 0 =R 2 Among them, p 2 and R 2 The grouting time is t1 The pressure at the grouting point and the diffusion distance of the slurry are combined (19) and (22), and the variables are separated and integrated to obtain the slurry diffusion radius control equation:

[0157]

[0158] 3) Phase change curing stage

[0159] When the grouting time reaches the phase change end time t 0 When the slurry enters the phase change solidification stage, the slurry front solidification circle breaks through, and the polyurethane particles formed after solidification gradually fill the pores of the porous medium due to the seepage effect, reducing its original permeability. As the slurry front forms a solidification layer again, the permeability of the porous medium decreases and gradually approaches 0.

[0160] The change of porosity is the main reason for the change of permeability. The change law of porosity during grouting is as follows:

[0161]

[0162] Among them, φ 0 is the porosity under initial effective stress conditions, φ r is the porosity of the porous medium measured under consolidated drainage conditions, σ e is the average effective stress (MPa), α is the compression coefficient (MPa -1 ). The Kozeny-Carman model is used to describe the permeability change:

[0163]

[0164] Consider the grouting pressure boundary condition: when p = p 0 When L 0 = r; when p = p 3 When L 0 =R 3 Among them, p 3 and R 3 The grouting time is t 2 The pressure at the grouting point and the diffusion distance of the slurry are combined (19) and (22), and the variables are separated and integrated to obtain the slurry diffusion radius control equation:

[0165]

[0166] Compared with the prior art, the beneficial effects of the embodiments of the present application are at least one of the following:

[0167] (1) The present application constructs a geometric model based on the actual physical structure and properties of the porous medium, which can more realistically reflect the complexity and irregularity of the porous medium, thereby improving the accuracy of the simulation; the physical field is established using the Richards equation and the porous medium dilute species transport equation. These two equations respectively describe the unsaturated seepage and material transfer processes of the fluid in the porous medium, which can more accurately reflect the seepage and diffusion behavior of polyurethane in the porous medium.

[0168] (2) This application can evaluate the permeability, diffusion and other properties of materials by simulating the seepage and diffusion behavior of different polyurethane materials in porous media, providing a basis for material selection and design.

[0169] (3) Through numerical simulation, this application can quickly evaluate the advantages and disadvantages of different grouting schemes or material schemes and improve decision-making efficiency.

[0170] Another embodiment of the present application provides a polyurethane penetration grouting diffusion simulation device. For details, see Figure 3 , Figure 3 The schematic diagram of the structure of the polyurethane penetration grouting diffusion simulation device provided in one embodiment of the present application includes the following modules: a construction module 11, an assignment module 12, a division module 13, and a calculation module 14, wherein

[0171] A construction module 11 is used to construct a geometric model of the penetration grouting and diffusion of polyurethane in the porous medium to be injected according to the physical property data of the porous medium to be injected;

[0172] An assignment module 12 is used to establish a physical field of the geometric model using the Richards equation and the porous medium dilute species transport equation, and adjust the geometric model according to the material property parameters of the geometric model obtained by the physical field, wherein the physical field reflects the influence of the material properties of the polyurethane on the seepage and diffusion process;

[0173] A division module 13 is used to set the boundary conditions and initial values ​​of the adjusted geometric model, and to perform mesh division on the adjusted geometric model based on a local refinement method to obtain a permeation grouting diffusion simulation model;

[0174] The calculation module 14 is used to solve the penetration grouting diffusion simulation model according to the transient solver to complete the simulation of the penetration grouting diffusion of the polyurethane in the porous medium to be injected.

[0175] Another embodiment of the present application provides a polyurethane infiltration grouting diffusion simulation device, including a processor 21, a memory 22, and a computer program stored in the memory 22 and configured to be executed by the processor 21. When the processor 21 executes the computer program, the steps in the above-mentioned polyurethane infiltration grouting diffusion simulation method embodiment are implemented, for example Figure 1 or, when the processor 21 executes the computer program, the functions of the modules in the above-mentioned device embodiments are implemented, such as constructing module 11.

[0176] Exemplarily, the computer program can be divided into one or more modules, which are stored in the memory 22 and executed by the processor 21 to complete the present application. The one or more modules can be a series of computer program instruction segments that can complete specific functions, and the instruction segments are used to describe the execution process of the computer program in the polyurethane penetration grouting diffusion simulation device. For example, the computer program can be divided into a construction module 11, an assignment module 12, a division module 13, and a calculation module 14.

[0177] The processor 21 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor 21 is the control center of the polyurethane infiltration grouting diffusion simulation device, and uses various interfaces and lines to connect various parts of the entire polyurethane infiltration grouting diffusion simulation device.

[0178] The memory 22 can be used to store the computer program and / or module. The processor 21 realizes various functions of the polyurethane infiltration grouting diffusion simulation device by running or executing the computer program and / or module stored in the memory 22 and calling the data stored in the memory 22. The memory 22 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), etc. In addition, the memory 22 can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0179] Wherein, if the module integrated in the polyurethane infiltration grouting diffusion simulation device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0180] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0181] Accordingly, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to perform the steps in the polyurethane infiltration grouting diffusion simulation method of the above embodiment, for example Figure 1 Steps S1 to S4 described in .

[0182] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A polyurethane penetration grouting diffusion simulation method, characterized in that: The following steps are involved: According to the physical property data of the porous medium to be injected, a geometric model of the penetration grouting and diffusion of polyurethane in the porous medium to be injected is constructed; The physical field of the geometric model is established by using the Richards equation and the porous medium dilute species transport equation, and the geometric model is adjusted according to the material property parameters of the geometric model obtained by the physical field, wherein the physical field reflects the influence of the material properties of the polyurethane on the seepage and diffusion process; Setting boundary conditions and initial values ​​of the adjusted geometric model, and meshing the adjusted geometric model based on a local refinement method to obtain a permeation grouting diffusion simulation model; The penetration grouting diffusion simulation model is solved according to the transient solver to complete the simulation of the penetration grouting diffusion of the polyurethane in the porous medium to be injected.

2. The polyurethane penetration grouting diffusion simulation method according to claim 1, characterized in that: The step of adjusting the geometric model according to the material property parameters of the geometric model obtained by the physical field comprises: Construct a diffusion model based on Newtonian fluid rheological equation and seepage motion equation; Obtaining the permeability function of the polyurethane in the porous medium to be injected in stages according to the diffusion model; Obtaining the dynamic viscosity of the polyurethane during the infiltration grouting diffusion process in the porous medium to be injected based on rheological experiments; The geometric model is adjusted by using the permeability function and the dynamic viscosity as material property parameters of the geometric model.

3. The polyurethane penetration grouting diffusion simulation method according to claim 2, characterized in that: The permeability function is expressed as: Where pwl(t) represents permeability, φ represents porosity, d represents pore diameter, t represents penetration time, t1 represents the time when flow resistance disappears, t2 represents slurry solidification time, δ represents porosity, ρ represents slurry density, and R represents the radius of porous media. is the integral median corresponding to the dynamic viscosity and penetration time function, φ0 and K0 are the porosity under the initial effective stress condition.

4. The polyurethane infiltration grouting diffusion simulation method according to claim 2, characterized in that: The dynamic viscosity is expressed as: μ(t)=C1·e kt +μ0 0≤t≤t2, Among them, μ(t) is the function of dynamic viscosity and time, μ0 is the initial viscosity of the slurry, t is time, t2 is the slurry flow-solid phase change time, k is the time-varying coefficient, and C1 is a constant.

5. The polyurethane penetration grouting diffusion simulation method according to claim 1, characterized in that: The step of constructing a geometric model of polyurethane infiltration grouting and diffusion in the porous medium to be injected according to the physical property data of the porous medium to be injected comprises: Based on the cross-section method, the diffusion process of the polyurethane in the porous medium to be injected is two-dimensionalized to obtain a two-dimensional model of the infiltration grouting; Determining geometric parameters of the two-dimensional model according to physical property data of the porous medium to be injected; A geometric model of the polyurethane in the porous medium to be injected is constructed based on an infinite source domain method and the geometric parameters.

6. The polyurethane infiltration grouting diffusion simulation method according to claim 1, characterized in that: The method of meshing the adjusted geometric model based on the local refinement method to obtain a permeation grouting diffusion simulation model includes: Performing preliminary meshing on the adjusted geometric model to obtain a sparse mesh; According to the simulation requirements of the geometric model, identifying the key areas in the sparse grid, the key areas at least including the grouting pipe area and the inner area of ​​the porous medium; The key area is meshed again based on a local refinement method to obtain a penetration grouting diffusion simulation model.

7. The polyurethane penetration grouting diffusion simulation method according to claim 1, characterized in that: The method of solving the penetration grouting diffusion simulation model according to the transient solver to complete the simulation of the penetration grouting diffusion of the polyurethane in the porous medium to be injected includes: According to the rheological equation of Newtonian fluid and the seepage motion equation, a partial differential equation corresponding to the infiltration grouting diffusion process of the polyurethane in the porous medium to be injected is set; Using an implicit Euler backward difference method to discretize the time term in the partial differential equation to obtain a discretized partial differential equation; The discretized partial differential equation is input into a pre-built transient solver for solving, and the penetration grouting diffusion process of the polyurethane in the porous medium is simulated by adjusting the number of iterations and the time step of the transient solver.

8. A polyurethane penetration grouting diffusion simulation device, characterized in that: Includes the following modules: A construction module, for constructing a geometric model of the penetration grouting and diffusion of polyurethane in the porous medium to be injected according to the physical property data of the porous medium to be injected; An assignment module, used for establishing a physical field of the geometric model by using the Richards equation and the porous medium dilute species transport equation, and adjusting the geometric model according to the material property parameters of the geometric model obtained by the physical field, wherein the physical field reflects the influence of the material properties of the polyurethane on the seepage and diffusion process; A partitioning module, used for setting boundary conditions and initial values ​​of the adjusted geometric model, and performing mesh partitioning on the adjusted geometric model based on a local refinement method to obtain a permeation grouting diffusion simulation model; The calculation module is used to solve the penetration grouting diffusion simulation model according to the transient solver to complete the simulation of the penetration grouting diffusion of the polyurethane in the porous medium to be injected.

9. A polyurethane penetration grouting diffusion simulation device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the polyurethane penetration grouting diffusion simulation method as described in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the polyurethane penetration grouting diffusion simulation method as described in any one of claims 1 to 7 is implemented.

Images