A method for estimating rock elastic modulus using a graphical method

Abstract

The present invention relates to a method for estimating rock elastic modulus by a chart method, and belongs to the technical field of rock mechanics. The present invention includes a point load experiment, elastic mechanics, the π theorem and numerical simulation. The point load experiment and elastic mechanics are used to establish the relationship between the rock elastic modulus and the point load experiment. The π theorem is used to integrate the relationship between the influencing factors of the rock elastic modulus. The π theorem is used to integrate the influencing factors of the rock elastic modulus in the point load experiment, and a fuzzy function relationship about the rock elastic modulus is obtained, that is, a numerical simulation method is then used to simulate the point load experiments of a large number of rock samples, and the numerical calculation results are substituted into the above-mentioned fuzzy function relationship, and the values ​​of the three dimensionless expressions of ES / P and F in the fuzzy function are calculated to obtain a dimensionless chart that can estimate the rock elastic modulus; when the point load experiment is used to measure the uniaxial compressive strength of the rock, the rock elastic modulus can be estimated synchronously.

Description

Technical Field

[0001] The invention relates to a method for estimating rock elastic modulus by using a chart method, and belongs to the technical field of rock mechanics. Background Art

[0002] Rock elastic modulus is one of the most important mechanical parameters in the field of rock engineering, and is also one of the indispensable mechanical parameters in numerical calculations. It has important reference significance for evaluating rock formation pressure, interlayer crack development, and rock stability. At present, the estimation of rock elastic modulus can be roughly divided into two experimental methods: static method and dynamic method. The former measures the stress and strain of rock through rock axial loading experiment, and then estimates the rock elastic modulus in combination with Hooke's theorem and rock strength criterion; the latter measures the longitudinal and transverse wave velocities inside the rock through rock acoustic wave experiment, and then estimates the rock elastic modulus in combination with elastic wave theory. However, there are many factors affecting the rock elastic modulus in actual engineering, and the area involved in the physical engineering is large, so that the indoor experiment is limited to the specific parameters of a certain theory and the number of rock samples, resulting in a large deviation between the estimated value of the rock elastic modulus and the actual value. Summary of the invention

[0003] Aiming at the problem that the rock elastic modulus is difficult to estimate and the deviation between the estimated value and the actual value is large, the present invention proposes a method for estimating the rock elastic modulus by using a chart method. The present invention uses the π theorem to integrate the influencing factors of the rock elastic modulus in the point load experiment to obtain a fuzzy function relationship about the rock elastic modulus; then a numerical simulation method is used to simulate the point load experiments of a large number of rock samples, and the numerical calculation results are substituted into the above-mentioned fuzzy function relationship to obtain a dimensionless chart for estimating the rock elastic modulus; when the uniaxial compressive strength of the rock is determined by the point load experiment, the rock elastic modulus can be estimated synchronously.

[0004] A method for estimating rock elastic modulus by graphical method, the specific steps are as follows:

[0005] (1) Based on the point load test and elastic mechanics analysis, the influencing factors related to the rock elastic modulus in the process of rock sample loading and failure in the point load test are obtained; the π theorem is used to integrate the influencing factors related to the rock elastic modulus in the process of rock sample loading and failure in the point load test, where the influencing factors include rock elastic modulus E, Poisson's ratio v, rock sample failure surface area S, rock sample failure load P, rock uniaxial compressive strength UCS, rock sample density ρ, gravitational acceleration g and size correction factor F. Combined with the principle of dimensional harmony, the fuzzy function related to the rock elastic modulus is obtained, namely,

[0006]

[0007] Where, E is the elastic modulus of rock, GPa; S is the area of ​​rock sample failure surface, m 2; P is the rock sample failure load, kN; UCS is the uniaxial compressive strength of rock, MPa; ρ is the rock sample density, kg / m 3 ; g is the acceleration due to gravity, m / s 2 ; F is the size correction coefficient, with a dimension of 1; since the rock Poisson's ratio v is a parameter with a dimension of 1, generally speaking, the value range of parameter v is not large. When estimating the rock elastic modulus using the graphical method, the rock Poisson's ratio is set to a constant value, and the parameter v can be ignored in the fuzzy function at this time;

[0008] (2) Taking the rock sample failure surface width w, rock sample failure load P, failure surface height d and elastic modulus E as basic variables, and assigning fixed values ​​to other influencing factors, numerical simulation software is used to increase the values ​​of the basic variables, namely, elastic modulus E, failure surface height d, rock sample failure load P and rock sample failure surface width w in sequence, so as to change the size and loading conditions of the numerical model to simulate the rock sample point load test under different working conditions, and calculate the dimensionless expressions ES / P, and the value of F;

[0009] The selected basic variables (rock sample failure surface width w, rock sample failure load P, failure surface height d and elastic modulus E) can simulate a large number of point load experiments and be used for iterative calculation of numerical simulation; by setting the initial values ​​(E0, d0, P0 and w0) and maximum values ​​(E max d max , P max and w max ), the number of numerical simulation groups can be flexibly adjusted. The smaller the gradient of the basic variable value, the more accurate the dimensionless curve is in estimating the elastic modulus.

[0010] (3) Using the dimensionless expression ES / P and are the horizontal and vertical axes of the dimensionless graph, respectively. According to step (2), the dimensionless expressions ES / P, , draw a dimensionless graph corresponding to a specific F value;

[0011] (4) Point load test of the rock sample to be estimated, and calculate the dimensionless expression based on the known rock sample failure surface area S, rock sample failure load P, rock uniaxial compressive strength UCS, rock sample density ρ, gravitational acceleration g and size correction factor F The value of ES / P is then obtained from the dimensionless chart corresponding to the specific F value in step (3), and the rock elastic modulus E is estimated based on the actual rock sample failure surface area S and rock sample failure load P.

[0012] The rock sample failure surface area S and rock sample failure load P are obtained according to the point load test; the rock sample density ρ is obtained through the bulk density test, and the gravity acceleration g is taken as 9.8m / s 2; The uniaxial compressive strength of rock UCS and the size correction factor F are selected according to the standard method recommended by the International Society of Rock Mechanics, specifically UCS = 15.8 + 12.27 × I s(50) , F=(D E / 50) 0.45 in, D E The unit is mm.

[0013] The numerical simulation software in step (2) is the finite element open source software Opensees.

[0014] The specific simulation calculation method of the numerical simulation software is:

[0015] 1) Using the loop statement in Python to change the numerical model size of the finite element open source software Opensees, the values ​​of the basic variables, namely the elastic modulus E, the failure surface height d, the rock sample failure load P and the rock sample failure surface width w, are increased in sequence;

[0016] 2) Use Python to call Opensees, load the numerical model and assign the boundary conditions of the point load experiment to perform numerical calculations to calculate the fuzzy function The dimensionless expression ES / P, and the value of F;

[0017] 3) The numerical calculation result, i.e., the dimensionless expression ES / P, The values ​​of and F are stored in a file with the suffix .out, and the data storage file is returned to Python.

[0018] The method for drawing the dimensionless graph corresponding to the specific F value in step (3) is to automatically draw it using the Matplotlib module in Python.

[0019] The beneficial effects of the present invention are:

[0020] (1) The present invention uses the π theorem to integrate the influencing factors of rock elastic modulus, combines the macroscopic experiment of the point load loading process of rock samples and the elastic mechanics analysis, establishes the relationship between the rock elastic modulus and the point load experiment, and can achieve synchronous estimation of the rock elastic modulus when the point load experiment is used to determine the uniaxial compressive strength of the rock;

[0021] (2) The present invention couples two methods, the π theorem and numerical simulation. The π theorem can integrate the influencing factors of rock elastic modulus. The numerical simulation can obtain a dimensionless chart for estimating rock elastic modulus by simulating rock sample point load experiments under different working conditions and calculating the value of the target influencing factor of rock elastic modulus, so as to facilitate rapid and accurate estimation of rock elastic modulus.

[0022] (3) The dimensionless diagram obtained by the coupling method of the π theorem and numerical simulation in the present invention takes into account various influencing factors of the rock elastic modulus and obtains massive data in combination with numerical simulation. The dimensionless diagram obtained can solve the factors considered in conventional experiments when estimating the rock elastic modulus and the defects of fewer samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of point load on irregular rock blocks;

[0024] Figure 2 Schematic diagram of the numerical model for point loading of rock samples;

[0025] Figure 3 Design solution flow charts for automated procedures;

[0026] Figure 4 It is the numerical calculation flow chart;

[0027] Figure 5 This is the effect diagram of the rock elastic modulus estimation method. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with specific implementation modes, but the protection scope of the present invention is not limited to the described contents.

[0029] The present invention includes point load experiment, elastic mechanics, π theorem and numerical simulation. The point load experiment and elastic mechanics are used to establish the relationship between rock elastic modulus and point load experiment. The π theorem is used to integrate the relationship between the influencing factors of rock elastic modulus. The π theorem is used to integrate the influencing factors of rock elastic modulus in point load experiment to obtain the fuzzy function relationship of rock elastic modulus, that is, Then, the numerical simulation method was used to simulate the point load test of a large number of rock samples, and the numerical calculation results were substituted into the above fuzzy function relationship to calculate the ES / P, The values ​​of the three dimensionless expressions of F and F are used to obtain a dimensionless chart that can be used to estimate the elastic modulus of rock. When the uniaxial compressive strength of rock is determined by point load test, the elastic modulus of rock can be estimated simultaneously.

[0030] The specific steps are as follows:

[0031] (1) Based on the point load test and elastic mechanics analysis, the influencing factors related to the rock elastic modulus in the process of rock sample loading and failure in the point load test are obtained; the π theorem is used to integrate the influencing factors related to the rock elastic modulus in the process of rock sample loading and failure in the point load test, where the influencing factors include rock elastic modulus E, Poisson's ratio v, rock sample failure surface area S, rock sample failure load P, rock uniaxial compressive strength UCS, rock sample density ρ, gravitational acceleration g and size correction factor F. Combined with the principle of dimensional harmony, the fuzzy function related to the rock elastic modulus is obtained, namely,

[0032]

[0033] Where, E is the elastic modulus of rock, GPa; S is the area of ​​rock sample failure surface, m 2 ; P is the rock sample failure load, kN; UCS is the uniaxial compressive strength of rock, MPa; ρ is the rock sample density, kg / m 3 ; g is the acceleration due to gravity, m / s 2 ; F is the size correction coefficient, with a dimension of 1; since the rock Poisson's ratio v is a parameter with a dimension of 1, generally speaking, the value range of parameter v is not large. When estimating the rock elastic modulus using the graphical method, the rock Poisson's ratio can be set to a constant value, and the parameter v can be ignored in the fuzzy function at this time;

[0034] (2) Taking the rock sample failure surface width w, rock sample failure load P, failure surface height d and elastic modulus E as basic variables, and assigning fixed values ​​to other influencing factors, numerical simulation software is used to increase the values ​​of the basic variables, namely, elastic modulus E, failure surface height d, rock sample failure load P and rock sample failure surface width w in sequence, so as to change the size and loading conditions of the numerical model to simulate the rock sample point load test under different working conditions, and calculate the dimensionless expressions ES / P, and the value of F;

[0035] (3) Using the dimensionless expression ES / P and are the horizontal and vertical axes of the dimensionless graph, respectively. According to step (2), the dimensionless expressions ES / P, , draw a dimensionless graph corresponding to a specific F value;

[0036] (4) Point load test of the rock sample to be estimated, and calculate the dimensionless expression based on the known rock sample failure surface area S, rock sample failure load P, rock uniaxial compressive strength UCS, rock sample density ρ, gravitational acceleration g and size correction factor F The value of ES / P is then obtained from the dimensionless chart corresponding to the specific F value in step (3), and the rock elastic modulus E is estimated based on the actual rock sample failure surface area S and rock sample failure load P.

[0037] Example 1: A method for estimating rock elastic modulus using a graphical method (see Figures 1 to 5 ), the specific steps are as follows:

[0038] (1) Figure 1 and Figure 2As shown in the figure, from the point load macroscopic experiment, it can be seen that the rock sample failure load P is related to the uniaxial compressive strength UCS of the rock, the rock sample failure surface area S and the size correction factor F. From the perspective of elastic mechanics, the failure load P can be regarded as a concentrated force applied to the top and bottom of the rock sample. At this time, the rock sample can be regarded as an elastic body in static equilibrium. According to the generalized Hooke's law, virtual displacement field and Gauss's theorem, the elastic body under this stress state can be expressed by the function

[0039] Φ(E,ν,Γ,σ ij ,b i ,p i )=0, where E is the rock elastic modulus, v is Poisson’s ratio, Γ is the definition domain of the geometric boundary, σ ij is the stress tensor, b i is the body force, p i is the external force acting on the boundary Γ; combined with the point load macroscopic experiment, it can be known that the parameter Γ can be replaced by the rock sample failure surface area S, and the parameter σ ij The uniaxial compressive strength of rock UCS can be used as a substitute, parameter b i The expression ρg can be used instead, and the parameter p i It can be replaced by the failure load P; therefore, during the point load loading process, the failure of the rock sample is related to the rock elastic modulus E, Poisson's ratio v, rock sample failure surface area S, rock sample failure load P, rock uniaxial compressive strength UCS, rock sample density ρ, gravity acceleration g and size correction coefficient F and other influencing factors, where S = w × d (w is the width of the rock sample failure surface, d is the height of the failure surface), and the fuzzy function Φ (E, ν, S, UCS, ρ, g, P, F) = 0 can be used to centrally represent it;

[0040] (2) The π theorem is widely used in the study of the hypothesis of complex physical phenomena. It can simplify the influencing factors of physical phenomena and optimize the experimental design. It achieves the optimal design of complex phenomena by setting basic variables and non-basic variables and combining the principle of dimensional harmony. For the fuzzy function Φ(E,ν,S,UCS,ρ,g,P,F)=0, the parameters E, S and ρ can be selected as basic variables. According to the π theorem,

[0041]

[0042]

[0043]

[0044] At this time, the function Φ(E,ν,S,σ t,ρ,g,P,F)=0 is equivalent to the function Φ(π1,π2,π3)=0. By harmonizing the dimensions on both sides of the above equation, we can know that β1=γ1=0,η1=-α1; β2=-α2 / 2,γ2=η2=-α2; β1=α3,γ3=0,η3=-α3. Then, the dimensionless expression can be used to characterize the load failure process of the rock sample point, which can be expressed as

[0045]

[0046] In the formula, the parameter F is a dimensionless quantity, and adding or omitting this parameter does not affect the expression of the fuzzy function characteristics;

[0047] To make the calculation more convenient, we can set α1 = -1, α2 = α3 = 1, then the above formula can be expressed as

[0048]

[0049] Since the dimensionless expression contained in the fuzzy function in the above formula can be freely multiplied and divided, the above formula can also be expressed as

[0050]

[0051] Where, E is the elastic modulus of rock, GPa; S is the area of ​​rock sample failure surface, m 2 ; P is the rock sample failure load, kN; UCS is the uniaxial compressive strength of rock, MPa; ρ is the rock sample density, kg / m 3 ; g is the acceleration due to gravity, m / s 2 ; F is the size correction factor, dimension is 1;

[0052] (3) In order to simplify the complicated operations in numerical simulation and facilitate the data acquisition and chart output of dimensionless charts, an automated program design scheme integrating numerical modeling, numerical calculation, data storage and chart output is constructed (such as Figure 3 and 4 ), taking the rock sample failure surface width w, rock sample failure load P, failure surface height d and elastic modulus E as basic variables, assigning fixed values ​​to other influencing factors, using numerical simulation software, sequentially increasing the values ​​of the basic variables, namely, elastic modulus E, failure surface height d, rock sample failure load P and rock sample failure surface width w, to change the size and loading conditions of the numerical model to simulate the rock sample point load test under different working conditions, and calculating the dimensionless expressions ES / P, and the value of F;

[0053] Specifically,

[0054] 1) The loop statement in Python is used to change the numerical model size of the finite element open source software Opensees, that is, to increase the values ​​of the basic variables, namely the elastic modulus E, the failure surface height d, the rock sample failure load P and the rock sample failure surface width w in sequence; the basic variables (rock sample failure surface width w, rock sample failure load P, failure surface height d and elastic modulus E) can simulate a large number of point load experiments and are also used for iterative calculations of numerical simulations; by setting the initial values ​​(E0, d0, P0 and w0) and the maximum values ​​(E max d max , P max and w max ), the number of numerical simulation groups can be flexibly adjusted. The smaller the gradient of the basic variable value, the more accurate the dimensionless curve is in estimating the elastic modulus.

[0055] 2) Use Python to call Opensees, load the numerical model and assign the boundary conditions of the point load experiment to perform numerical calculations to calculate the fuzzy function The dimensionless expression ES / P, and the value of F;

[0056] 3) The numerical calculation result, i.e., the dimensionless expression ES / P, The values ​​of and F are stored in a file with the suffix .out, and the data storage file is returned to Python;

[0057] (4) Using the dimensionless expression ES / P and The dimensionless graph is represented by the horizontal axis or vertical axis, respectively. Using the Matplotlib module in Python, the dimensionless expressions ES / P, The value of F will automatically draw a dimensionless chart corresponding to a specific F value;

[0058] The dimensionless diagram obtained under a certain set of basic variables is shown in Figure 5 , and ES / P are set as the vertical and horizontal axes of the dimensionless graph, respectively;

[0059] (5) Point load test of the rock sample to be estimated, and calculate the dimensionless expression based on the known rock sample failure surface area S, rock sample failure load P, rock uniaxial compressive strength UCS, rock sample density ρ, gravitational acceleration g and size correction factor F The value of the dimensionless graph is the vertical axis The value of the dimensionless expression ES / P is then queried according to the dimensionless chart corresponding to the specific F value in step (3), i.e., the value of the dimensionless expression ES / P on the horizontal axis, and the rock elastic modulus E is estimated according to the actual rock sample failure surface area S and the rock sample failure load P;

[0060] The rock sample failure surface area S and rock sample failure load P are obtained according to the point load test; the rock sample density ρ is obtained through the bulk density test, and the gravity acceleration g is taken as 9.8m / s 2 The uniaxial compressive strength of rock UCS and the size correction factor F are selected according to the standard method recommended by the International Society of Rock Mechanics, specifically UCS = 15.8 + 12.27 × I s(50) , F=(4S / 50π) 0.45 Among them, I s(50) =FPπ / 4S;

[0061] Figure 5 The dimensionless chart in is a rendering in the embodiment, which is only used to illustrate the estimation method of rock elastic modulus;

[0062] By establishing the relationship between the rock elastic modulus and the point load test, the rock elastic modulus can be estimated synchronously when the uniaxial compressive strength of the rock is determined by the point load test. The dimensionless chart obtained by the coupling method of the π theorem and numerical simulation takes into account various influencing factors of the rock elastic modulus, and combines numerical simulation to obtain massive data. The dimensionless chart obtained can solve the factors considered in conventional experiments when estimating the rock elastic modulus and the defects of small samples.

[0063] Example 2: In order to facilitate understanding and supplement the method of estimating rock elastic modulus by the graphical method described in Example 1, specific parameters are selected for illustration;

[0064] The diagrams used to estimate the elastic modulus of rock require a large amount of data; therefore, Figure 4 In the numerical calculation process, the rock sample failure surface width w, rock sample failure load P, failure surface height d and elastic modulus E are selected as basic variables to simulate a large number of point load experiments, and the number of numerical simulation groups can be flexibly adjusted; the product of parameter w and parameter d is the rock sample failure surface area, and a variety of rock sizes can be obtained by changing parameters w and d, thereby providing multiple groups of rock sample models for numerical calculation; for different rock sample models, loads are applied according to a certain gradient until the rock sample failure load P is recorded, so the applied load should be a variable; the elastic modulus is set as a variable to provide a certain reference for estimating the rock elastic modulus by the graphical method;

[0065] According to the actual project, Figure 4 Among the basic variables, parameter w can be selected from 2cm, 4cm, 6cm, 8cm and 10cm; parameter P can be selected from 0.1 to 50kN, and the pressure is continuously applied, while the load P when the rock sample fails is recorded; parameter d can be selected from 2cm, 4cm, 6cm, 8cm and 10cm; parameter E can be selected from 10GPa, 30GPa, 50GPa, 70GPa and 90GPa; parameter S = w×d, then parameter F = (4S / 50π) 0.45can be calculated; other parameters are fixed, and parameter ρ is 2700kg / m 3 , parameter g is 9.8m / s, parameter v is 0.23;

[0066] use Figure 4 The numerical calculation process can be obtained by multiple sets of dimensionless charts. The present invention only uses the dimensionless chart corresponding to w=2cm in Example 2 to specifically illustrate the estimation method of the elastic modulus; after a rock block is destroyed by a point load test, its failure load P is measured to be 1.19kN, the width w of the failure surface is 2.0cm, and the height d of the failure surface is 2.3cm, then the size correction coefficient F is 0.723; using the standard method recommended by the International Society for Rock Mechanics, the uniaxial compressive strength UCS of the rock is estimated to be 17.98MPa; thus, Figure 5 Vertical axis It can be calculated, and its value is 3.16×10 4 ; Because the size correction factor F is 0.723, the value is between Figure 5 In the figure, F = 0.699 and F = 0.817, the dimensionless curve corresponding to F = 0.723 can be drawn according to the interval ratio (such as Figure 5 As shown by the solid red line in the figure; Figure 5 As shown, based on the calculated value, intersecting it with the red solid line, the horizontal coordinate ES / P at the intersection can be calculated, and its value is about 7.8×10 3 , because the parameter P = 1.19 kN, the parameter S = w × d = 0.02 × 0.023 = 4.6 × 10 -4 m, from ES / P, we can know that the rock elastic modulus E = 20.17 GPa, which is the elastic modulus value estimated by the graphical method.

[0067] The specific implementation modes of the present invention are described in detail above, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for estimating rock elastic modulus by graphical method, characterized in that: Including the setting of safety isolation area, reinforced concrete wall and waste rock bulk pile, the specific steps are as follows: (1) The π theorem is used to integrate the influencing factors related to the rock elastic modulus during the loading and failure process of the rock sample in the point load experiment. The influencing factors include the rock elastic modulus E, Poisson's ratio v, rock sample failure surface area S, rock sample failure load P, rock uniaxial compressive strength UCS, rock sample density ρ, gravitational acceleration g and size correction factor F. The fuzzy function related to the rock elastic modulus is obtained by combining the dimensional harmony principle, namely: Where, E is the elastic modulus of rock, GPa; S is the area of ​​rock sample failure surface, m 2 ; P is the rock sample failure load, kN; UCS is the uniaxial compressive strength of rock, MPa; ρ is the rock sample density, kg / m 3 ; g is the acceleration due to gravity, m / s 2 ; F is the size correction factor, dimension is 1; (2) Taking the rock sample failure surface width w, rock sample failure load P, failure surface height d and elastic modulus E as basic variables, and assigning fixed values ​​to other influencing factors, numerical simulation software is used to increase the values ​​of the basic variables, namely, elastic modulus E, failure surface height d, rock sample failure load P and rock sample failure surface width w in sequence, so as to change the size and loading conditions of the numerical model to simulate the rock sample point load test under different working conditions, and calculate the dimensionless expressions ES / P, and the value of F; (3) Using the dimensionless expression ES / P and are the horizontal and vertical axes of the dimensionless graph, respectively. According to step (2), the dimensionless expressions ES / P, , draw a dimensionless graph corresponding to a specific F value; (4) Point load test of the rock sample to be estimated, and calculate the dimensionless expression based on the known rock sample failure surface area S, rock sample failure load P, rock uniaxial compressive strength UCS, rock sample density ρ, gravitational acceleration g and size correction factor F The value of ES / P is then obtained from the dimensionless chart corresponding to the specific F value in step (3), and the rock elastic modulus E is estimated based on the actual rock sample failure surface area S and rock sample failure load P.

2. The method for estimating rock elastic modulus by graphical method according to claim 1, characterized in that: The numerical simulation software in step (2) is the finite element open source software Opensees.

3. The method for estimating rock elastic modulus by graphical method according to claim 2, characterized in that: The specific simulation calculation method of the numerical simulation software is: 1) Using the loop statement in Python to change the numerical model size of the finite element open source software Opensees, the values ​​of the basic variables, namely the elastic modulus E, the failure surface height d, the rock sample failure load P and the rock sample failure surface width w, are increased in sequence; 2) Use Python to call Opensees, load the numerical model and assign the boundary conditions of the point load experiment to perform numerical calculations to calculate the fuzzy function The dimensionless expression ES / P, and the value of F; 3) The numerical calculation result, i.e., the dimensionless expression ES / P, The values ​​of and F are stored in a file with the suffix .out, and the data storage file is returned to Python.

4. The method for estimating rock elastic modulus by graphical method according to claim 3, characterized in that: The method for drawing the dimensionless graph corresponding to the specific F value in step (3) is to automatically draw it using the Matplotlib module in Python.

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