Compensation method and device for incomplete similarity of discontinuous fractured rock mass model test

Abstract

The invention provides a compensation method and device for incomplete similarity of a discontinuous fractured rock mass model test, and belongs to the technical field of geomechanical model tests. The method comprises the following steps: determining a compensation formula of a discontinuous fractured rock mass model according to a model type of the discontinuous fractured rock mass model; according to the compensation formula of the discontinuous fractured rock mass model and pi-item distortion occurring in the test process of the discontinuous fractured rock mass model, obtaining a distortion parameter of a compensation pi item; and generating a compensation model of the discontinuous fractured rock mass model according to the distortion parameters. According to the method and the device, the compensated model can better represent the condition of the prototype.

Description

Technical Field

[0001] The present application relates to the technical field of geomechanical model tests, and in particular to a method and device for compensating for incomplete similarity in a discontinuous fractured rock mass model test. Background Art

[0002] In recent years, the development and utilization of deep space, underground resources and energy storage and extraction have become important directions of scientific and technological development, such as the construction of deep tunnels and Jinping underground laboratory, geological disposal of high-level radioactive waste, geological storage of carbon dioxide, and development and utilization of medium- and deep-layer geothermal resources. Due to the extreme nature of the deep environment, the complexity of multi-field coupling, and the discontinuity of the storage medium, the basic theoretical research of deep engineering usually lags behind its engineering activities, resulting in a certain degree of blindness, inefficiency and uncertainty in engineering activities such as the development and utilization of deep space, and the storage and extraction of deep resources and energy.

[0003] At present, conducting three-dimensional physical model tests on underground projects with complex geological conditions is still one of the important directions of rock engineering research today. The main research content of the physical model test of rock engineering is the geomechanical model test, among which the selection of similar materials and the determination of relevant parameters based on the physical and mechanical properties of the prototype are one of the key factors of the geomechanical model test, which is directly related to the accuracy of the model test. The most widely used similarity criterion in geomechanical model tests is the similarity criterion determined based on the differential equation of continuous medium mechanics.

[0004] However, due to the limitations of objective conditions such as materials, processes, technologies and experimental environment, it is difficult to use similarity criteria based on continuous medium mechanics differential equations for discontinuous structural surfaces such as faults and fracture zones because the interlayers of the structural surfaces are very thin or the deformation modulus is very low. However, the fractured rock mass in the deep earth environment has the characteristic of prominent discontinuity, which makes it difficult for existing geomechanical model tests to characterize the prototype of the rock mass with discontinuity characteristics, and there is a problem of poor accuracy of model tests. Summary of the invention

[0005] The embodiments of the present application provide a method and device for compensating for the incomplete similarity of a discontinuous fractured rock mass model test, so as to solve the problem that the existing geomechanical model test is difficult to characterize the prototype of a rock mass with discontinuous characteristics and has poor accuracy of the model test.

[0006] In a first aspect, an embodiment of the present application provides a method for compensating for incomplete similarity in a discontinuous fractured rock mass model test, comprising:

[0007] According to the model type of the discontinuous fractured rock mass model, a compensation formula of the discontinuous fractured rock mass model is determined;

[0008] According to the compensation formula of the discontinuous fractured rock mass model and the π-term distortion occurring during the discontinuous fractured rock mass model test, the distortion parameter for compensating the π-term is obtained;

[0009] According to the distortion parameters, a compensation model of the discontinuous fractured rock mass model is generated.

[0010] In a second aspect, an embodiment of the present application provides a compensation device for incomplete similarity in a discontinuous fractured rock mass model test, comprising:

[0011] A compensation formula determination module, used for determining a compensation formula of a discontinuous fractured rock mass model according to a model type of the discontinuous fractured rock mass model;

[0012] A distortion parameter calculation module is used to obtain a distortion parameter for compensating the π term according to a compensation formula of a discontinuous fractured rock mass model and the π term distortion occurring during the test of the discontinuous fractured rock mass model;

[0013] The compensation model generation module is used to generate a compensation model of a discontinuous fractured rock mass model according to distortion parameters.

[0014] The embodiment of the present application provides a method and device for compensating for incomplete similarity in a discontinuous fractured rock model test. First, according to the model type of the discontinuous fractured rock model, the compensation formula of the discontinuous fractured rock model is determined. Then, according to the compensation formula of the discontinuous fractured rock model and the π-term distortion that occurs during the discontinuous fractured rock model test, the distortion parameter for compensating the π-term is obtained. Finally, according to the distortion parameter, a compensation model of the discontinuous fractured rock model is generated. In this way, by studying the influence of the distortion of each similarity criterion on the model, a compensation method for an incompletely similar model of a fractured rock is proposed, which can make the compensated model better represent the situation of the prototype. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 It is a schematic diagram of the principle of a distortion model provided in an embodiment of the present application;

[0017] Figure 2 It is a flow chart for realizing a compensation method for incomplete similarity of a discontinuous fractured rock mass model test provided by an embodiment of the present application;

[0018] Figure 3 is a schematic diagram of a single fracture model provided in an embodiment of the present application;

[0019] Figure 4 It is a schematic diagram of the relationship between the π-term distortion ratio of a single crack model and the average normal displacement distortion ratio of the model provided in an embodiment of the present application;

[0020] Figure 5 is a schematic diagram of a fracture network model provided in an embodiment of the present application;

[0021] Figure 6 It is a schematic diagram of the relationship between the π-term distortion ratio of a fracture network finite element model and the average normal displacement distortion ratio of the model provided in an embodiment of the present application;

[0022] Figure 7 It is a schematic diagram of an underground chamber model provided in an embodiment of the present application;

[0023] Figure 8 It is a schematic diagram of the relationship between the π-term distortion ratio of a fractured rock underground chamber model and the normal displacement distortion ratio of a model monitoring point provided in an embodiment of the present application;

[0024] Fig. 9 This is a model provided in the embodiment of the present application under the limit failure state π 5 and π 6 Distortion ratio relationship diagram;

[0025] Fig.10 It is a schematic diagram comparing the displacement cloud diagrams of a completely similar model and a distortion compensation model provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0027] In order to make the purpose, technical solutions and advantages of the present application clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0028] As described in the related art, existing geomechanical model tests are difficult to characterize the prototype of a rock mass with discontinuous characteristics, and there is a problem of poor accuracy of the model test.

[0029] In order to solve the problems of the prior art, the embodiment of the present application provides a method and device for compensating for the incomplete similarity of a discontinuous fractured rock mass model test. The method for compensating for the incomplete similarity of a discontinuous fractured rock mass model test provided by the embodiment of the present application is first introduced below.

[0030] First, the research ideas of this application are introduced.

[0031] This application derives the similarity relationship of the complete similarity model test of the fractured rock mass, and then analyzes the influence of the distortion of each similarity criterion on the model when the fractured rock mass is not completely similar based on the similarity relationship. In this way, by studying the influence of the distortion of each similarity criterion on the model, a compensation method for the incomplete similarity model of the fractured rock mass is proposed, which can make the compensated model better represent the prototype.

[0032] The following is a detailed analysis and introduction of similarity criteria and incomplete similarity.

[0033] In similar studies, since fractured rock mass under complex conditions is non-continuous and the basic theory of deep earth engineering is not yet complete, using equations to analyze the similarity relationship of fractured rock mass under deep earth environment will complicate the problem. However, dimensional analysis is not limited to the mathematical theory of known equations. It has certain advantages in using it in complex physical phenomena whose mechanisms are not yet clear and whose laws are not yet fully understood. Therefore, this application uses dimensional analysis to determine the similarity relationship of fractured rock mass, and a series of dimensionless terms can be obtained using Buckingham's π theorem.

[0034] The physical quantities that affect the structural performance in fractured rock mass are as follows:

[0035] L size, ρ density, g gravity coefficient, c joint cohesion, Joint internal friction angle, E elastic modulus of rock matrix, μ Poisson's ratio of rock matrix, K n Normal stiffness of joint, K s The tangential stiffness of the joints, σ ​​rock matrix stress, σ f Rock mass fracture stress, ε rock mass matrix strain, ε f Rock mass crack strain, u rock mass matrix displacement, t time, P external load, d crack width. In the mass system, the basic dimensions are used to express the dimensions of these quantities:

[0036]

[0037] The number of physical quantities n=17, the number of basic dimensions k=3 in the mass system, that is, the dimensions of mass M, length L and time T are basic dimensions, and the number of zero dimensions m=4, so the similarity criteria nk=14 that can be established (including 4 independent similarity criteria composed of zero-dimensional physical quantities). L, ρ, and g are selected as basic physical quantities, and the dimension matrix is ​​shown in Table 1.

[0038] Table 1 Dimensional matrix

[0039]

[0040] From the dimensional matrix and the principle of dimensional harmony, 14 similarity criteria can be obtained:

[0041]

[0042] When π p =π m When , the fractured rock mass model is completely similar, and the model can represent the prototype. Definition of the similarity ratio of each parameter:

[0043]

[0044] Based on the above similarity criteria, the similarity relationship of various parameters of fractured rock mass can be obtained as shown in Table 2.

[0045] Table 2 Similarity relationships of various parameters of fractured rock mass

[0046]

[0047]

[0048] According to the definition of incomplete similarity model, i.e. distortion model, in similarity theory shows that the incomplete similarity of fractured rock mass mechanical model is caused by the non-satisfaction of some π terms during model design. Therefore, the study of influencing factors of incomplete similarity of fractured rock mass mechanical model is the study of the influence of the distortion of π term on the model.

[0049] The similarity theory dimensional analysis method can accurately obtain all the π terms of the model. p =π m1 (p is the prototype, m1 is the similar model) is a completely similar model, that is, the model does not produce distortion. p ≠π m1 (p is the prototype, m is the model) when the model is not completely similar, that is, the model is distorted, and a distortion coefficient δ is introduced π π p =π m2 (m2 is the distortion model) to represent the degree of distortion of the π term. The distortion coefficients of the physical parameters of the model are expressed by δ △ m1 △ =m2 △ To express (δ represents the degree of distortion of each parameter of the distortion model, △ represents the physical parameters of the model). The principle of the distortion model is as follows Figure 1 shown.

[0050] Based on the above analysis, a compensation method for the incomplete similarity model of fractured rock mass is proposed, which is mainly divided into two steps: 1) determining the influencing factors of the incomplete similarity of the mechanical model test of fractured rock mass; 2) establishing a compensation method based on the mechanical model test of fractured rock mass.

[0051] Specifically, since there are many influencing factors in the fractured rock model test, and different influencing factors have different adaptability conditions for different models, specific compensation methods are proposed for different types of fractured rock model tests that are not completely similar, namely, the compensation method for the single fracture model, the compensation method for the fracture network model, and the compensation method for the underground chamber excavation model. Among them, the single fracture model and the fracture network model regard the fracture with width as a filler, and use the average normal displacement of the model as the compensation condition for compensation; the underground chamber excavation model uses the damage of the top structural surface of the chamber and the displacement of the monitoring point at the top of the cave roof as the compensation condition for compensation.

[0052] See also Figure 2 , which shows a flow chart for implementing the incomplete similarity compensation method for the discontinuous fractured rock mass model test provided by the embodiment of the present application, and is described in detail as follows:

[0053] Step 210: Determine a compensation formula for the discontinuous fractured rock mass model according to the model type of the discontinuous fractured rock mass model.

[0054] In some embodiments, the model types of the discontinuous fractured rock mass model can be divided into a single fracture model, a fracture network model and an underground chamber model, and the underground chamber model is further divided into a stable model after excavation and a damaged underground chamber model after excavation. Different types of discontinuous fractured rock mass models have corresponding different compensation formulas.

[0055] Step 220: Obtain distortion parameters for compensating the π term according to the compensation formula of the discontinuous fractured rock mass model and the π term distortion occurring during the discontinuous fractured rock mass model test.

[0056] In some embodiments, the π term that fails to satisfy the complete similarity relationship during the discontinuous fractured rock mass model test may be determined as π term distortion. Afterwards, the distortion ratio of the π term distortion is substituted into the compensation formula, and at least one π term is selected to calculate the distortion ratio of the compensated π term, thereby obtaining the distortion parameter of the compensated π term.

[0057] Step 230: Generate a compensation model of the discontinuous fractured rock mass model according to the distortion parameters.

[0058] In some embodiments, the model parameters may be modified first to achieve a distortion ratio that compensates for the π term. If the normal displacement distortion ratio of the model is within a preset interval, the model at this time is determined as a compensation model for a discontinuous fractured rock mass model. If the normal displacement distortion ratio of the model is not within the preset interval, the step of "selecting at least one π term to calculate the distortion ratio that compensates for the π term, and modifying the model parameters to achieve a distortion ratio that compensates for the π term" is repeated until the normal displacement distortion ratio of the model is within the preset interval, and the model at this time is determined as a compensation model for a discontinuous fractured rock mass model.

[0059] The following specifically introduces the compensation methods for different types of discontinuous fractured rock models and provides verification examples.

[0060] 1. Compensation method and verification of incomplete similarity of single crack model.

[0061] 1.1 Compensation method for incomplete similarity of single fracture model

[0062] The single crack model simulation experiment uses a plane strain crack thin plate model under uniaxial compression. The prototype is granite. The material is given elastic modulus E, Poisson's ratio μ, and density ρ. The crack filling material is given elastic modulus E. f , Poisson's ratio μ f , density ρ f .like Figure 3 As shown, the model adopts a non-penetrating fracture model, and the parameters of the prototype and the completely similar model are shown in Table 3.

[0063] Table 3 Parameters of the prototype and the completely similar model

[0064]

[0065] The physical quantities that affect the structural performance of the known single crack mechanical model are side length L, matrix elastic modulus E, matrix Poisson's ratio μ, matrix density ρ, crack width d, and crack filler elastic modulus E. f , Poisson's ratio μ f , density ρ f and external load P.

[0066] Different similarity criteria can be obtained by selecting different basic physical quantities according to the conditions of basic physical quantities. Taking ρ, g, and L as basic physical quantities can make it easier and more convenient to study the influencing factors, compensation, and correction methods of incomplete model similarity. Based on this, this application takes ρ, g, and L as basic physical quantities. Taking ρ, g, and L as basic physical quantities, seven similarity criteria can be obtained as follows:

[0067]

[0068] To analyze the incomplete similarity influencing factors of the single fracture mechanical model of fractured rock mass, it is necessary to consider the influence of the distortion of the above seven similarity criteria on the model. Assuming that all similarity criteria are distorted, it can be expressed as:

[0069]

[0070] From (2), it can be seen that the distortion coefficient of the similarity criterion is affected by the similarity ratio of the model parameters. Since the change of the similarity ratio of the model parameters has no effect on the model when the distortion coefficient of the similarity criterion remains unchanged, the equation of the similarity criterion can be simplified. In the process of physical model testing, the size and gravity acceleration of the model can be controlled so that it does not distort, so the size distortion ratio δL and the gravity acceleration distortion ratio δg are considered to be 1. Since the influence of the π-term distortion on the model is fixed, it can be assumed that the density does not distort, thereby simplifying the distortion equations of each π-term as follows:

[0071]

[0072] Therefore, the distortion of the seven similarity criteria π terms derived from the basic physical quantities ρ, g, and L can be regarded as the single-factor distortion of seven physical parameters, namely, the elastic modulus E, the crack width d, the Poisson's ratio μ, and the elastic modulus E of the crack filling material. f , Poisson's ratio μ f , density ρ f and the distortion of the external load P.

[0073] At present, in the physical model test of rock mass engineering, scholars usually focus on observing the strain and failure characteristics during the model experiment. Therefore, this application aims to evaluate the quasi-similarity between the incompletely similar model and the prototype by comparing the ratio between the average normal displacement of the model and the average normal displacement of the completely similar model after compensating and correcting the incompletely similar model.

[0074] When studying the incomplete similarity influencing factors of the mechanical model of a single fracture in a fractured rock mass, we first theoretically analyze the influence of the distortion of the single-factor physical parameters on the average normal displacement of the model. Specifically, according to the normal strain formula (4) in the isotropic linear elastic constitutive relation of rock, the normal strain of the model under isotropic conditions is inversely proportional to the elastic modulus of the model; and linearly related to the Poisson's ratio and normal stress of the model. In this regard, the normal strain formula of the fracture can be written as formula (5) after treating the fracture as a low-density, low-elastic modulus filler. The normal strain of the fracture is inversely proportional to the elastic modulus of the fracture filler, and linearly related to the Poisson's ratio and normal stress of the model.

[0075]

[0076]

[0077] Based on formulas (4) and (5), it can be seen that the distortion of the elastic modulus of rock and the distortion of the elastic modulus of the crack filling material have an inversely proportional effect on the normal strain; the distortion of the Poisson's ratio of rock and the distortion of the Poisson's ratio of the crack filling material have a linear relationship on the normal strain. Therefore, it can be assumed that the distortion of the elastic modulus of rock, the distortion of the elastic modulus of the crack filling material, the distortion of the Poisson's ratio of rock and the distortion of the Poisson's ratio of the crack filling material in the anisotropic fractured rock mass model composed of rock and fractures have an unchanged influence on the overall average normal displacement distortion of the model. Combined with the definition of distortion ratio of single-factor physical parameters, it can be assumed that the relationship between the elastic modulus distortion ratio, Poisson's ratio distortion ratio, crack filler elastic modulus distortion ratio and crack filler Poisson's ratio distortion ratio and the average normal displacement distortion ratio should be the same as the relationship between the elastic modulus, Poisson's ratio, crack filler elastic modulus and crack filler Poisson's ratio and strain in formulas (4) and (5), which can be expressed as formulas (6) and (7).

[0078]

[0079]

[0080] The normal stress distortion ratio and the average normal displacement distortion ratio of the single crack mechanical model under the combined action of gravity and external load should be the same as the relationship between the normal stress ratio and strain in formulas (6) and (7), that is, they are all linear relationships. In this regard, it can be assumed that the normal stress and external load distortion ratios under gravity are still linearly related to the average normal displacement distortion ratio. The normal stress under gravity is related to the model matrix density, crack filling material density, gravitational acceleration and size. The distortion of gravitational acceleration and size can be avoided in the model test. Therefore, it is assumed that the matrix density, crack filling material density and external load are linearly related to the average normal displacement distortion ratio, which can be expressed by (8), (9) and (10).

[0081] δ n =ad ρ +b(a+b=1,d ρ ,δ n >0) (8)

[0082] δ n =ad ρf +b(a+b=1,d ρf ,δ n >0) (9)

[0083] δ n =aδ P +b(a+b=1,δ P ,δ n >0) (10)

[0084] When conducting physical model tests of fractured rock mass, it is difficult to simulate small fractures completely in the large-scale physical model process. Therefore, when considering the influence of fracture width distortion on the average normal displacement of the model, it is necessary to consider the larger distortion of the fracture width. The distortion of the gap width will cause changes in the model itself. When the distortion ratio gradually increases, the proportion of the fracture in the total model continues to increase. Since the fracture is regarded as a low elastic modulus and low density filler, it can be assumed that the normal displacement distortion ratio of the model is linearly related to the gap width distortion ratio. The linear relationship can be expressed as (11).

[0085] δ n =aδ d +b(a+b=1,δ d ,δ n >0) (11)

[0086] After the crack width is distorted, the model itself changes. At this time, except for the crack width, the distortion of other single-factor physical parameters is the same as the functional relationship when the crack width is not distorted, but the coefficient has changed. Therefore, it is necessary to consider the impact of the change in crack width on the relationship with the average normal displacement distortion during the single-factor physical parameter distortion process. If the influence on the relationship with the average normal displacement distortion during the single-factor physical parameter distortion process under the action of the extreme crack width distortion ratio is small, then it can be ignored, and the subsequent research is completed according to the relationship function between the two when the crack width is not distorted. However, if the influence is large, the two-dimensional curve function relationship with the average normal displacement distortion during the single-factor physical parameter distortion process is converted into a three-dimensional surface function relationship considering the crack width distortion. It is known that the normal displacement distortion ratio of the model is linearly related to the crack width distortion ratio. When the relationship between the distortion ratio of the single factor physical parameter and the average normal displacement distortion ratio of the model is linear, the three-dimensional functional relationship between the normal displacement distortion ratio of the model considering the crack width distortion and the single factor physical parameter distortion ratio can be expressed by formula (12). When the relationship between the distortion ratio of the single factor physical parameter and the average normal displacement distortion ratio of the model is inversely proportional, the three-dimensional surface functional relationship considering the crack width distortion can be expressed by formula (13).

[0087] δ n =aδ d d △ +bδ d +cd △ +d,(d △ ,δ d ,δ n >0,a+b+c+d=1) (12)

[0088]

[0089] Based on the previous analysis of the influencing factors of the incomplete similarity of the single fracture mechanical model of fractured rock mass, finite element simulation was carried out to verify the relationship between the distortion of the single factor physical parameters of the model after prototype scaling and the distortion of the average normal displacement. The corresponding laws were summarized from these relationships, and a compensation and correction method for the incomplete similarity of the single fracture mechanical model of fractured rock mass was proposed.

[0090] After the single-crack non-penetration model is scaled down, the seven π-term similarity criteria are distorted respectively. The distortion of the single-factor physical parameter in formula (3) is used to represent the distortion of the π-term. Keeping other variables unchanged, the relationship between the distortion ratio of different similarity criteria and the average normal displacement distortion ratio of the model after compression is analyzed.

[0091] Among the seven similarity criteria that can be obtained based on ρ, g, and L as basic physical quantities, the distortions of π1, π2, and π7 are related to the distortions of elastic modulus, crack elastic modulus, and density of crack filling materials. In the process of making similar materials for actual physical model tests, the distortions of the three can be controlled within a very small range. Therefore, in numerical simulation, the distortion ratios of π1, π2, and π7 are simulated between 0.5 and 2. The distortion of π3 is related to the distortion of crack width. Most crack widths in rock mass engineering are often very small, and it is difficult to simulate the situation where the crack width is less than 1 mm during large-scale physical model tests. Therefore, the simulation of the distortion ratio of π3 is carried out between 0.2 and 100. The distortion of π3 is related to the distortion of external loads. The external load can well control its parameters in the actual physical model test and can be well used as a compensation item. Therefore, the distortion ratio of π3 is simulated between 0.2 and 5. The distortion of π5 and π6 is the Poisson's ratio and crack filler Poisson's ratio distortion. It is known that the Poisson's ratio of materials ranges from 0 to 0.5, so π5 and π6 are simulated between the distortion ratio of 0.6 and 1.4 to control the range of the distorted Poisson's ratio to be between 0 and 0.5.

[0092] This application is based on the method of numerical simulation to study the compensation and correction method of the incomplete similarity of the mechanical model of a single fracture in a fractured rock mass. Figure 3 The model is used as the prototype, and a scaled model with a size similarity ratio of 100 is established using finite elements and the calculation is completed. Then the single-factor physical parameters of the model are modified to achieve the target distortion ratio, and the final average normal displacement distortion ratio of the model is recorded. Each single-factor physical parameter is distorted 5 times, and finally the data points are plotted on a chart with the horizontal axis as the π-term distortion ratio and the vertical axis as the average normal displacement distortion ratio. The fitting formula is used to fit the data points to obtain the relationship function between the π-term distortion ratio and the average normal displacement distortion ratio.

[0093] At the same time, a model with a crack width distortion ratio of 100 is established and the calculation is completed. The relationship curve is established in the same way as the above steps. If the parameter ratio of the relationship function with a crack width distortion ratio of 100 and the relationship function with no crack width distortion is within the range of 0.95-1.05, it is considered that the crack width distortion ratio has little effect on the relationship between the single factor physical parameter distortion and the average normal displacement distortion and can be ignored. In this case, the subsequent study is carried out according to the relationship function when the crack width is not distorted. However, if the ratio is not within the range of 0.95-1.05, it is necessary to distort the single factor physical parameter 5 times when the crack width distortion ratio is 10, 25, 50, and 100, record the final average normal displacement distortion ratio of the model, plot these data points in a three-dimensional graph with the crack width distortion ratio as the X-axis, the single factor physical parameter distortion as the Y-axis, and the model average normal displacement as the Z-axis, and fit them using formulas (12) and (13) to obtain the final function surface relationship.

[0094] The relationship between the single factor physical parameter distortion ratio of the single crack mechanical model and the model average normal displacement distortion ratio is the same as the relationship between the π term distortion ratio and the model average normal displacement distortion ratio. Finally, the π term distortion ratio and the model average normal displacement distortion ratio diagram are obtained, as shown in Figure 4 shown.

[0095] By analyzing the incomplete similarity influencing factors of the single crack model, the average normal displacement distortion ratio and π 3 , π 4 , π 5 , π 6 , π 7 The conclusion that the distortion ratio is linearly related. 6 , π 7 The distortion has little effect on the average normal displacement of the model, so it is not included in the scope of distortion compensation and correction. In addition, π obtained based on ρ, g, and L is 1 and π 2 The ratio is inversely proportional to each other and is also affected by the π3 distortion ratio. This single crack model uses ρ, g, and L as the basic physical quantities, and the π-term distortion formula (14) is:

[0096]

[0097] Therefore, the distortion formula (15) of the π term based on ρ, g, and L can be summarized as follows:

[0098]

[0099] After determining the distortion formulas of each π-term distortion and the average normal displacement of the model, since the distortion formula of each π-term independently affects the average normal displacement of the model, the distortion formula of the average normal displacement of the model under multiple π-term distortions can be expressed by formula (17).

[0100] δ n =d n1 ·d n2 ·d n3 ·d n4 ·d n5 (δ ni >0,i=1……5,δ n >0) (17)

[0101] When the model's average normal displacement is δ n = 1, the average normal displacement of the model is not distorted. At this time, the incomplete similarity model achieves the same test results as the complete similarity model through distortion compensation. The compensation formula for the incomplete similarity of the single fracture mechanical model of fractured rock mass is expressed by formula (18).

[0102] δ n1 ·d n2 ·d n3 2d n4 ·d n5 =1(δ ni >0,i=1·····5) (18)

[0103] When one or more π items fail to meet the complete similarity condition in the process of scaling down the single fracture model of fractured rock mass, the distortion ratio of the π items that fail to meet the complete similarity relationship can be substituted into the compensation formula (18), and one or more π items that are easy to control and change during the test are selected as the compensation π items, and the calculation is completed to obtain the distortion ratio of the compensation π items. After all parameters are obtained, the model test is redesigned, and finally the distortion compensation is completed to make the model test close to the actual situation.

[0104] 1.2 Verification of the compensation method for incomplete similarity of single fracture model

[0105] According to the above research on the single-crack mechanical model of fractured rock mass, it is found that only the distortion of 5 π terms has a greater influence on the average normal displacement distortion of the model. Therefore, when conducting numerical simulation verification, the distortion ratios of 4 π terms are randomly selected within the distortion range of each π term for simulation. However, it is necessary to ensure that the selected compensation π term has a significant effect on the average normal displacement distortion ratio of the model within the distortion range. The distortion ratio of the compensation π term can be obtained by substituting the selected distortion ratio into the compensation formula, and the model parameters are modified to achieve the distortion ratio of each π term. Subsequently, a simulation test is carried out to obtain the average normal displacement of the final model. Then the average normal displacement distortion ratio δ of the incompletely similar model is calculatedn If the average normal displacement distortion ratio δn of all compensated models is between 0.95 and 1.05, it can be considered that the compensated models have achieved the test results achieved by completely similar models, that is, the compensation method is effective.

[0106] The average normal displacement distortion ratio δ of the incompletely similar model after compensation based on the similarity criteria of ρ, g, L and E, g, L n The results are shown in Table 4.

[0107] Table 4 Compensation method verification

[0108] ρ, g, L are the distortion ratios of the basic physical quantities δn <![CDATA[π 1 =2、π 2 =0.5、π 3 =100、π 4 =1.2、π 5 =0.678]]> 1.02415 <![CDATA[π 1 =0.5、π 2 =0.5、π 3 =25、π 4 =1.4、π 5 =1.0215]]> 1.03749 <![CDATA[π 1 =2.1、π 2 =1.4、π 3 =8、π 4 =0.62、π 5 =0.85]]> 1.008684

[0109] From Table 4, we can see that the δ of the incomplete similarity model after using the compensation method to compensate for the π term is n Both are between 0.95 and 1.05. Therefore, the average normal displacement of the incompletely similar model after using the compensation method reaches the test result achieved by the completely similar model. The compensation method is effective.

[0110] 2. Compensation method and verification of incomplete similarity of fracture network models

[0111] 2.1 Compensation method for incomplete similarity of fracture network models

[0112] Taking the fracture network model of 100 random fractures as an example, the factors affecting the incomplete similarity of the fracture network mechanical model of fractured rock mass and the compensation and correction methods are studied. The plane strain uniaxial compression model of the fracture network is established using finite element software. Granite is used as the prototype, and the fracture network model material is an elastic material. The matrix elastic modulus E, Poisson's ratio μ, and density ρ are given. When simulating the fracture width, the fracture is regarded as a filler with low elastic modulus E and low density ρ and the fracture elastic modulus E is given. f , Poisson's ratio μ f and density ρ f ,like Figure 5 As shown, a diagram of the mechanical model of a single fracture in a fractured rock mass is shown.

[0113] The fracture network model and the single fracture model have the same model structure and mechanical parameters except for the number of fractures. Therefore, the incomplete similarity influencing factors of the fracture network mechanical model of fractured rock mass are the same as the incomplete similarity influencing factors of the single fracture mechanical model of fractured rock mass. The similarity criterion, distortion equation and single factor distortion equation obtained by the fracture network model with ρ, g and L as the basic physical quantities are shown in the above equations (1) to (3).

[0114] The relationship between the distortion of a single factor physical parameter and the average normal displacement of the model is the same as the relationship between the distortion of a single factor physical parameter and the average normal displacement of the model in the single crack model (6) to (11). The relationship between the distortion of the average normal displacement and the change of the crack width in the crack network model during the distortion of a single factor physical parameter is the same as the relationship between the distortion of the average normal displacement and the change of the crack width in the single crack model during the distortion of a single factor physical parameter, as shown in formulas (12) and (13).

[0115] Based on the above analysis of the influencing factors of the incomplete similarity of the fracture network mechanical model of fractured rock mass, finite element simulation was carried out to verify the relationship between the distortion of the single factor physical parameters of the model after prototype scaling and the distortion of the average normal displacement, and the corresponding laws were summarized from these relationships, and a compensation and correction method for the incomplete similarity of the fracture network mechanical model of fractured rock mass was proposed.

[0116] When performing finite element simulation to verify the relationship between the distortion of the single factor physical parameter of the model after prototype scaling and the distortion of the average normal displacement, the process is the same as the process of verifying the relationship between the distortion of the single factor physical parameter of the model after prototype scaling of the single crack model and the distortion of the average normal displacement. The relationship between the single factor physical parameter distortion ratio of the crack network mechanics model and the average normal displacement distortion ratio of the model is the same as the relationship between the π-term distortion ratio and the average normal displacement distortion ratio of the model. Finally, the π-term distortion ratio and the average normal displacement distortion ratio of the model are obtained, as shown in Figure 6 shown.

[0117] By analyzing the incomplete similarity factors of the crack network model, the average normal displacement distortion ratio and π 5 , π 6 , π 7 The distortion ratio is linearly related; the model average normal displacement distortion ratio and π 2 , π 3 , the distortion ratio is linearly related and is affected by π 5 The influence of distortion ratio. 7 The distortion has little effect on the average normal displacement of the model, so it is not included in the scope of distortion compensation and correction. In addition, the average normal displacement distortion ratio of the model and π obtained based on ρ, g, and L are 1 and π 4 is inversely proportional to π 5 The influence of distortion ratio. The finite element model of the fracture network is based on the distortion formula (19) of the basic physical quantities ρ, g, and L.

[0118]

[0119] Therefore, the distortion formula (20) of the π term based on ρ, g, and L can be summarized.

[0120]

[0121] After determining the distortion formulas of each π-term distortion and the average normal displacement of the model, since the distortion formula of each π-term independently affects the average normal displacement of the model, the distortion formula of the average normal displacement of the model under multiple π-term distortions can be expressed by formula (21).

[0122] δ n =d n1 ·d n2 ·d n3 ·d n4 ·d n5 ·d n6 (δ ni >0,i=1·····6,δ n >0) (21)

[0123] When the model's average normal displacement is δ n = 1, the average normal displacement of the model is not distorted. At this time, the incomplete similarity model achieves the same test results as the complete similarity model through distortion compensation. The compensation formula for the incomplete similarity of the single fracture mechanical model of fractured rock mass is expressed by formula (22).

[0124] δ n1 ·d n2 ·d n3 ·d n4 ·d n5 ·d n6 =1(δ ni >0,i=1·····6) (22)

[0125] 2.2 Verification of the compensation method for incomplete similarity of fracture network models

[0126] According to the above research on the finite element model of fractured rock mass fracture network, it is found that only the distortion of 6 π terms has a greater influence on the average normal displacement distortion of the model. Therefore, when conducting numerical simulation verification, the distortion ratios of 6 π terms are randomly selected within the distortion range of each π term for simulation. However, it is necessary to ensure that the selected compensation π term has a significant effect on the average normal displacement distortion ratio of the model within the distortion range. The distortion ratio of the compensation π term can be obtained by substituting the selected distortion ratio into the compensation formula, and the model parameters are modified to achieve the distortion ratio of each π term. Subsequently, a simulation test is carried out to obtain the average normal displacement of the final model. Then the average normal displacement distortion ratio δ of the incompletely similar model is calculated n If the average normal displacement distortion ratio of all compensated models is δ n If both are between 0.95 and 1.05, it can be considered that the compensated model has achieved the experimental results achieved by the completely similar model, that is, the compensation method is effective.

[0127] The average normal displacement distortion ratio δ of the incompletely similar model after compensation based on the similarity criteria of ρ, g, L and E, g, L n The results are shown in Table 5.

[0128] Table 5 Compensation method verification

[0129]

[0130] It can be seen from Table 5 that the δ of the incomplete similarity model after compensating the π term using the compensation method is n Both are between 0.95 and 1.05. Therefore, the average normal displacement of the incompletely similar model after using the compensation method reaches the test result achieved by the completely similar model. The compensation method is effective.

[0131] By comparing the compensated model with the prototype displacement cloud map, it can be analyzed that the displacement of each block of the model after distortion compensation is basically the same as that of the prototype, which can reflect the phenomenon of the prototype. Therefore, this method can make the compensation method effective.

[0132] 3. Compensation method and verification of incomplete similarity of underground chamber models

[0133] The mechanical model of the underground chamber in fractured rock mass was constructed using two-dimensional discrete element software. The model is based on the excavation of the chamber. First, the equilibrium state before excavation is established to ensure that the stress reaches equilibrium before actual excavation. The excavation shape is horseshoe-shaped. The focus is on observing whether there is damage on the top of the chamber, and monitoring the strain changes of the three monitoring points on the top during the excavation process. The size and boundaries of the model after excavation are as follows Figure 7 The composition of the joint fracture network is based on the fracture structural plane with a mean value of 45° and a variance of 2, and the fracture structural plane with a mean value of 135° and a variance of 2. Taking granite as the material prototype, the material properties of the fractured rock mass underground chamber mechanical model are shown in Table 6.

[0134] Table 6 Mechanical parameters of underground chamber model

[0135]

[0136] The fractured rock mass underground chamber model and the fracture network mechanics model are both discrete element models and have the same model parameters. Therefore, the fractured rock mass underground chamber model is not completely similar to the fracture network mechanics discrete element model in terms of influencing factors. The similarity criterion, distortion equation and single factor distortion equation of the fracture network model based on ρ, g and L are shown in (23) to (25).

[0137]

[0138]

[0139]

[0140] From (25), it can be seen that the distortion of the incomplete similarity factor π of the fractured rock underground chamber model can be converted into the distortion of the seven single factors of the physical parameters. The influence of the single factor physical parameter distortion on the normal displacement of the monitoring point of the stable underground chamber model is the same as the influence of the single factor of the fracture network discrete element model of the fractured rock mass on the average normal displacement. The relationship between the single factor physical parameter distortion of the underground chamber stability model and the normal displacement of the model monitoring point is as follows (6)~(10), (12)~(13)

[0141] When studying the incomplete similarity compensation of underground chamber models, the prototypes are divided into two types: one is the chamber model that is stable after excavation, namely the stable model; the other is the chamber model that is destroyed after excavation, namely the destroyed model.

[0142] The main difference between the stable model and the failure model is the difference in top load, while the material and boundary conditions remain the same. For the stable model, the relationship between the distortion of the single-factor physical parameters and the normal displacement of the cave roof under the stable state of the model is analyzed, and the corresponding laws are summarized from these relationships. Based on the above laws, the compensation method of the fracture network discrete element model of the fractured rock mass is used to compensate the distortion model within the range of the model stability parameters. For the failure model, it is necessary to find out the single-factor distortion factors that affect the model failure through single-factor distortion, and use the dichotomy method to explore the relationship between these single-factor distortions under the extreme failure state, and summarize the compensation law of the failure model accordingly.

[0143] 3.1 Compensation method for incomplete similarity of underground chamber stability models

[0144] The relationship between the distortion of the single factor physical parameters of the model and the distortion of the normal displacement of the monitoring point after the single fracture model prototype was scaled down was verified using discrete element software. The relationship between the single factor physical parameter distortion ratio of the mechanical model of the fracture network underground chamber model and the model average normal displacement distortion ratio is the same as the relationship between the π term distortion ratio and the model average normal displacement distortion ratio. Finally, the π term distortion ratio and the model average normal displacement distortion ratio diagram are obtained, as shown in Figure 8 shown.

[0145] When analyzing the incomplete similarity influencing factors of the fracture network discrete element model, the model displacement distortion ratio of the monitoring point where the block falls off is defined as 10, so that the π-term limit distortion ratio that causes the block fall off model can be clearly identified in the π-term distortion and displacement distortion relationship diagram. From the data analysis, it can be seen that for a stable chamber model, π 5 and π 6The distortion will cause the model to change from a stable state to a damaged state, at which point the distortion model and the prototype are no longer consistent in state. Therefore, when analyzing the effect of the distortion of the stable state model on the displacement, it is necessary to exclude the π-term distortion ratio data points of the blocks that have fallen off after the distortion, and use the fitting function relationship of the fracture network discrete element model of the fractured rock mass when fitting the function.

[0146] In addition, π 6 and π 7 The distortion of the two π terms is related to the shear strength of the model structure surface. Under load, π 6 and π 7 The distortion may cause some structural surfaces in the model to switch between the damaged state and the stable state. Due to the differences in the position and angle of the structural surface, the stresses they bear are different, so it is difficult to accurately analyze whether the structural surface has been damaged. 6 and π 7 The relationship between the distortion ratio of the monitoring point and the displacement distortion ratio is uncertain. Therefore, when compensating the stable underground chamber model, π is not considered. 6 and π 7 The influence of the distortion on the displacement of the model monitoring points.

[0147] According to the fitting function relationship diagram, the average normal displacement distortion ratio and π of the model can be obtained. 2 , π 5 The distortion ratio is linearly related; the model average normal displacement distortion ratio and π 1 , π 3 , π 4 The distortion ratio is inversely proportional. The model diagram of the underground chamber in fractured rock mass is based on the distortion formula (26) of the basic physical quantities ρ, g, and L.

[0148]

[0149] Therefore, the distortion formula of the π term based on ρ, g, and L can be summarized as (27):

[0150]

[0151] After determining the distortion formulas of each π term and the normal displacement of the underground chamber monitoring point, since the distortion formula of each π term independently affects the normal displacement of the model monitoring point, the distortion formula of the normal displacement of the monitoring point under multiple π term distortions is expressed by formula (28).

[0152] δ n =d n1 ·d n2 ·d n3 ·d n4 ·d n5 (δ ni>0,i=1……5,δ n >0) (28)

[0153] When the distortion ratio of the normal displacement of the monitoring point is δn=1, the normal displacement of the model monitoring point is not distorted. At this time, the incomplete similarity model achieves the same test results as the complete similarity model through distortion compensation. The compensation formula for the incomplete similarity of the stability model of the underground chamber in fractured rock mass is expressed by formula (29).

[0154] δ n1 ·d n2 ·d n3 ·d n4 ·d n5 =1(δ ni >0,i=1·····5) (29)

[0155] When conducting a scaled study of an underground chamber model, if it is found that one or more π terms cannot meet the complete similarity condition, the distortion ratio of the π terms that cannot meet the complete similarity relationship can be substituted into the compensation formula (29). In this process, one or more π terms that are easy to control and change during the test are selected as compensation π terms, and calculations are performed to obtain the distortion ratio of the compensation π terms. After obtaining all parameters, the model test is redesigned and the distortion compensation is finally completed, so that the model test can be closer to the actual situation. During the compensation process, it should be noted that an excessively large external load distortion ratio may cause the model to be damaged. Therefore, when compensating the stable model, the external load distortion ratio should be as small as possible from 1.

[0156] 3.2 Verification of compensation method for incomplete similarity of underground chamber stability model

[0157] According to the above research on the stability model of underground chambers in fractured rock mass, the distortion of the five π terms has a great influence on the average normal displacement distortion of the model. Therefore, when conducting numerical simulation verification, the distortion ratios of 5 π terms are randomly selected within the distortion range of each π term for simulation. However, it is necessary to ensure that the selected compensation π term has a significant effect on the normal displacement distortion ratio of the model monitoring point within the distortion range. The distortion ratio of the compensation π term can be obtained by substituting the selected distortion ratio into the compensation formula, and the model parameters are modified to achieve the distortion ratio of each π term. Subsequently, a simulation test is carried out to obtain the normal displacement of the monitoring point of the final model. Then the normal displacement distortion ratio δ of the monitoring point of the incompletely similar model is calculated n If the normal displacement distortion ratio of each monitoring point of all compensated models is δ n If both are between 0.95 and 1.05, it can be considered that the compensated model has achieved the experimental results achieved by the completely similar model, that is, the compensation method is effective.

[0158] The normal displacement distortion ratio δ of the monitoring point of the incompletely similar model after compensation based on the similarity criteria of the basic physical quantities ρ, g, and L n The results are shown in Table 7.

[0159] Table 7 Compensation method verification

[0160]

[0161]

[0162] From Table 7, we can see that the δ of the incomplete similarity model after using the compensation method to compensate for the π term is n Both are between 0.95 and 1.05. Therefore, the average normal displacement of the incompletely similar model after using the compensation method reaches the test result achieved by the completely similar model. The compensation method is effective.

[0163] By comparing the compensated model with the prototype displacement cloud map, it can be analyzed that the displacement of each block in the model after distortion compensation is basically the same as that of the prototype, which can reflect the phenomenon of the prototype. Therefore, the compensation method is effective.

[0164] 3.3 Compensation method for incomplete similarity of underground chamber failure models

[0165] Through the relationship diagram between the π-term distortion ratio of the stable model and the normal displacement distortion ratio of the model monitoring point, it can be known that π 5 and π 6 The distortion will cause the model to change from a stable state to a damaged state. In order to ensure that the scaled model is still in a damaged state consistent with the prototype, the π 5 and π 6 The distortion relationship is determined to compensate the model after the model destruction conditions are met.

[0166] For the destruction model, the material and boundary conditions are consistent with the stable model. Increasing the load on the top of the model causes the block on the top of the chamber to fall off, which is defined as a destruction model. In the discrete element software, the fractured rock mass is elastic, and the structural surface is given Coulomb slip of surface contact. Its destruction principle is the Coulomb criterion of the structural surface. Therefore, the falling of the block on the top of the chamber is caused by the shear strength of the structural surface being greater than the shear strength. It can be seen that the compensation for the destruction model is different from the fixed value of the stable model, but a range. When the shear strength of the structural surface is greater than the shear strength, the model can well characterize the prototype. Therefore, it is necessary to find π under the limit destruction state of the structural surface on the top of the chamber. 5 and π 6 The relationship between the distortion ratios of the items is used to determine the compensable range.

[0167] In the study of underground chamber physical model destruction test, after the model is made, loading to destroy it is often the last process of the test. Therefore, the π 6 As a distortion term, the π related to the external load in the ultimate failure state of the model is found by dichotomy 5 Then, the model is subjected to the ultimate failure state. 6 and π 5 The distortion ratio is shown in the figure and fitted through a linear relationship. The fitted figure is as follows: Fig. 9 shown.

[0168] Determine the π under the ultimate failure state of the model 5 and π 6 After the distortion ratio relationship is obtained, formula (30) is satisfied when compensating the distortion model, that is, Fig. 9 The medium dark area can make the scaled model match the destroyed state of the prototype.

[0169] d p5 >1.3146d p6 -0.31249(d p5 ,d p6 >0) (30)

[0170] The compensation formula for the incomplete similarity of the failure model of underground chambers in fractured rock mass is expressed by formula (31).

[0171] d p5 >ad p6 -b(d p5 ,d p6 >0) (31)

[0172] When conducting underground chamber excavation failure model tests, if some π terms cannot meet the completely similar conditions, it is only necessary to make π 5 and π 6 In the process of distortion, satisfying formula (31) can make the model present the destroyed state of the prototype and complete the distortion compensation.

[0173] 3.4 Verification of compensation method for incomplete similarity of underground chamber failure models

[0174] According to the above research on the failure model of underground chamber in fractured rock mass, the distortion of two π terms affects the failure of the model. Therefore, when conducting numerical simulation verification, we randomly select π 6 Substitute the distortion ratio into formula (30) to find the corresponding π 5The distortion ratio of the selected distortion ratio can be obtained by substituting the selected distortion ratio into the compensation formula, and the model parameters are modified to achieve the distortion ratio of each π term. Then a simulation test is carried out to observe the normal displacement of the monitoring point and whether there is a block falling off the top. If the blocks falling off the top of all compensated models are consistent with the prototype, it can be considered that the compensated model has achieved the test results achieved by the completely similar model, that is, the compensation method is effective.

[0175] Two distortion models are selected to verify the compensation of the damage model. 6 The distortion ratio and π 5 The distortion ratio is adjusted to make it conform to the relationship of formula (30), and then the excavation calculation of the underground chamber model is carried out to observe whether the block falling off the top of the model is consistent with the prototype. Fig.10 It can be seen that the destruction of the two distortion models is consistent with the completely similar model, so it can be recognized that the compensation method is effective.

[0176] In the embodiment of the present application, firstly, the compensation formula of the discontinuous fractured rock model is determined according to the model type of the discontinuous fractured rock model, then the distortion parameter for compensating the π term is obtained according to the compensation formula of the discontinuous fractured rock model and the π term distortion that occurs during the test of the discontinuous fractured rock model, and finally, the compensation model of the discontinuous fractured rock model is generated according to the distortion parameter. In this way, by studying the influence of the distortion of each similarity criterion on the model, a compensation method for the incomplete similarity model of the fractured rock is proposed, which can make the compensated model better represent the situation of the prototype.

[0177] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0178] The following is an embodiment of the device of the present application. For details not described in detail, please refer to the corresponding method embodiment described above.

[0179] The compensation devices for the discontinuous fractured rock mass model test are not completely similar, including:

[0180] A compensation formula determination module, used for determining a compensation formula of a discontinuous fractured rock mass model according to a model type of the discontinuous fractured rock mass model;

[0181] A distortion parameter calculation module is used to obtain a distortion parameter for compensating the π term according to a compensation formula of a discontinuous fractured rock mass model and the π term distortion occurring during the test of the discontinuous fractured rock mass model;

[0182] The compensation model generation module is used to generate a compensation model of a discontinuous fractured rock mass model according to distortion parameters.

[0183] In some embodiments, the distortion parameter calculation module is specifically used to:

[0184] The π term that cannot satisfy the complete similarity relationship during the discontinuous fractured rock mass model test is determined as π term distortion;

[0185] The distortion ratio of the π-term distortion is substituted into the compensation formula, and at least one π-term is selected to calculate the distortion ratio of the compensated π-term, so as to obtain the distortion parameter of the compensated π-term.

[0186] In some embodiments, the compensation model generation module is specifically used to:

[0187] Modify the model parameters to achieve the distortion ratio that compensates the π term;

[0188] If the normal displacement distortion ratio of the model is within a preset range, the model at this time is determined as a compensation model of the discontinuous fractured rock mass model;

[0189] If the normal displacement distortion ratio of the model is not within the preset range, the step of “selecting at least one π term to calculate the distortion ratio of the π term for compensation, and modifying the model parameters to achieve the distortion ratio of the π term for compensation” is repeated until the normal displacement distortion ratio of the model is within the preset range, and the model at this time is determined as the compensation model of the discontinuous fractured rock model.

[0190] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0191] In addition, the features of the embodiments shown in the drawings of the present application or the various embodiments mentioned in this specification are not necessarily understood as independent embodiments. Instead, each feature described in one example of an embodiment can be combined with one or more other desired features from other embodiments to produce other embodiments not described in words or with reference to the drawings.

[0192] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0193] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method for compensating for incomplete similarity in a discontinuous fractured rock mass model test, characterized in that: include: According to the model type of the discontinuous fractured rock mass model, a compensation formula of the discontinuous fractured rock mass model is determined; According to the compensation formula of the discontinuous fractured rock mass model and the π-term distortion occurring during the discontinuous fractured rock mass model test, the distortion parameter for compensating the π-term is obtained; According to the distortion parameters, a compensation model of the discontinuous fractured rock mass model is generated.

2. The incomplete similarity compensation method for discontinuous fractured rock mass model test according to claim 1 is characterized in that: The method of determining the compensation formula of the discontinuous fractured rock mass model according to the model type of the discontinuous fractured rock mass model comprises: When the model type of the discontinuous fractured rock mass model is a single fracture model, the compensation formula is: d n1 ·d n2 ·d n3 ·d n4 ·d n5 =1(δ ni >0,i=1·····5) Among them, π1-π5 are the π terms obtained based on the rock matrix density ρ, gravitational acceleration g, and size L. The subscript p in the π term represents the prototype, the subscript m in the π term represents the fractured rock model, and δ π Represents the distortion coefficient of different π terms, E f represents the elastic modulus of the crack filling material, E represents the elastic modulus, d represents the crack width, μ represents the Poisson's ratio of the rock matrix, and P represents the external load.

3. The incomplete similarity compensation method for discontinuous fractured rock mass model test according to claim 1 is characterized in that: The method of determining the compensation formula of the discontinuous fractured rock mass model according to the model type of the discontinuous fractured rock mass model comprises: When the model type of the discontinuous fractured rock mass model is a fracture network model, the compensation formula is: d n1 ·d n2 ·d n3 ·d n4 ·d n5 ·d n6 =1(δ ni >0,i=1·····6) Among them, π1-π6 are the π terms obtained based on the rock matrix density ρ, gravitational acceleration g, and size L. The subscript p in the π term represents the prototype, the subscript m in the π term represents the fractured rock model, and δ π Represents the distortion coefficient of different π terms, E f represents the elastic modulus of the crack filling material, E represents the elastic modulus, d represents the crack width, μ represents the Poisson's ratio of the rock matrix, P represents the external load, μ f represents the Poisson's ratio of the fracture filling material.

4. The incomplete similarity compensation method for discontinuous fractured rock mass model test according to claim 1 is characterized in that: The method of determining the compensation formula of the discontinuous fractured rock mass model according to the model type of the discontinuous fractured rock mass model comprises: When the model type of the discontinuous fractured rock mass model is an underground chamber model that is stable after excavation, the compensation formula is: d n1 ·d n2 ·d n3 ·d n4 ·d n5 =1(δ ni >0,i=1·····5) Among them, π1-π5 are the π terms obtained based on the rock matrix density ρ, gravitational acceleration g, and size L. The subscript p in the π term represents the prototype, the subscript m in the π term represents the fractured rock model, and δ π represents the distortion coefficient of different π terms, E represents the elastic modulus, μ represents the Poisson's ratio of the rock matrix, K n represents the normal stiffness of the joint, K s represents the tangential stiffness of the joint, and P represents the external load.

5. The incomplete similarity compensation method for discontinuous fractured rock mass model test according to claim 1 is characterized in that: The method of determining the compensation formula of the discontinuous fractured rock mass model according to the model type of the discontinuous fractured rock mass model comprises: When the model type of the discontinuous fractured rock mass model is an underground chamber model destroyed after excavation, the compensation formula is: d π5 >ad π6 -b(d π5 ,d π6 >0) Among them, π6 is the π term obtained based on the basic physical quantities of rock matrix density ρ, gravitational acceleration g, and size L, and c is the joint cohesion.

6. The method for compensating for incomplete similarity in a discontinuous fractured rock mass model test according to any one of claims 1 to 5, characterized in that: The distortion parameters for compensating the π term are obtained according to the compensation formula of the discontinuous fractured rock mass model and the π term distortion occurring during the discontinuous fractured rock mass model test, including: The π term that cannot satisfy the complete similarity relationship during the discontinuous fractured rock mass model test is determined as π term distortion; The distortion ratio of the π-term distortion is substituted into the compensation formula, and at least one π-term is selected to calculate the distortion ratio of the compensated π-term, so as to obtain the distortion parameter of the compensated π-term.

7. The incomplete similarity compensation method for discontinuous fractured rock mass model test according to claim 6 is characterized in that: The method of generating a compensation model of a discontinuous fractured rock mass model according to the distortion parameters includes: Modify the model parameters to achieve the distortion ratio that compensates the π term; If the normal displacement distortion ratio of the model is within a preset range, the model at this time is determined as a compensation model of the discontinuous fractured rock mass model; If the normal displacement distortion ratio of the model is not within the preset range, the step of "selecting at least one π term to calculate the distortion ratio of the π term for compensation, and modifying the model parameters to achieve the distortion ratio of the π term for compensation" is repeated until the normal displacement distortion ratio of the model is within the preset range, and the model at this time is determined as the compensation model of the discontinuous fractured rock mass model.

8. A compensation device for incomplete similarity in a discontinuous fractured rock mass model test, characterized in that: include: A compensation formula determination module, used for determining a compensation formula of a discontinuous fractured rock mass model according to a model type of the discontinuous fractured rock mass model; A distortion parameter calculation module is used to obtain a distortion parameter for compensating the π term according to a compensation formula of a discontinuous fractured rock mass model and the π term distortion occurring during the discontinuous fractured rock mass model test; The compensation model generation module is used to generate a compensation model of a discontinuous fractured rock mass model according to distortion parameters.

9. The incomplete similarity compensation device for discontinuous fractured rock mass model test according to claim 8, characterized in that: The distortion parameter calculation module is specifically used for: The π term that cannot satisfy the complete similarity relationship during the discontinuous fractured rock mass model test is determined as π term distortion; The distortion ratio of the π-term distortion is substituted into the compensation formula, and at least one π-term is selected to calculate the distortion ratio of the compensated π-term, so as to obtain the distortion parameter of the compensated π-term.

10. The incomplete similarity compensation device for discontinuous fractured rock mass model test according to claim 9, characterized in that: The compensation model generation module is specifically used for: Modify the model parameters to achieve the distortion ratio that compensates the π term; If the normal displacement distortion ratio of the model is within a preset range, the model at this time is determined as a compensation model of the discontinuous fractured rock mass model; If the normal displacement distortion ratio of the model is not within the preset range, the step of "selecting at least one π term to calculate the distortion ratio of the π term for compensation, and modifying the model parameters to achieve the distortion ratio of the π term for compensation" is repeated until the normal displacement distortion ratio of the model is within the preset range, and the model at this time is determined as the compensation model of the discontinuous fractured rock mass model.

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