Rock characteristic stress threshold identification method and device, electronic equipment and storage medium

Abstract

This application relates to a method, apparatus, electronic device, and storage medium for identifying rock characteristic stress thresholds, comprising: determining the initial damage variables of a rock sample to be tested; determining the peak stress and peak strain of the rock sample to be tested, and constructing a damage model describing the relationship between initial damage and rock deformation and failure processes based on the peak stress and peak strain and the initial damage variables; generating a damage model curve based on the damage model, and determining the crack initiation strain threshold and crack damage strain threshold based on the damage model curve; and mapping the crack initiation stress and crack damage stress based on a preset rock axial stress-strain curve and the crack initiation strain threshold and crack damage strain threshold. This solves the problems of high cost, strong subjectivity, poor repeatability, and limited applicability in related technologies, achieving accurate, objective, and efficient identification of key characteristic stresses such as rock crack initiation stress and crack damage stress.

Description

Technical Field

[0001] This application relates to the field of rock mechanics and rock mass engineering stability evaluation technology, and in particular to a method, device, electronic device and storage medium for identifying rock characteristic stress thresholds. Background Technology

[0002] The assessment of the mechanical properties of rock materials is fundamental to rock engineering design and stability analysis. Under complex environmental conditions such as freeze-thaw cycles, high temperature and high pressure, and chemical corrosion, rocks will develop primary and secondary damage of varying degrees, significantly affecting their subsequent deformation and failure characteristics and long-term stability.

[0003] During the deformation process in front of the rock peak, the internal microcracks undergo a gradual evolution process of closure, initiation, propagation, and eventual penetration. It is generally believed that there are four typical characteristic stress thresholds: crack closure stress... Crack initiation stress Crack damage stress and peak stress .in, This marks the initiation of new cracks and is the starting point for damage accumulation; The stress level corresponding to the transition from stable to unstable crack propagation can serve as an important indicator of the long-term strength of rock. Accurately identifying these characteristic stress thresholds is of great significance for rock mass damage assessment and engineering instability prediction.

[0004] In existing technologies, the crack volumetric strain (CVS) method is the primary method for identifying characteristic stress thresholds. This method requires simultaneous acquisition of axial and radial strain data, and interprets the characteristics of the volumetric strain curve. , Feature points. However, the CVS method has the following shortcomings: (1) It requires circumferential displacement or radial strain testing equipment, the test setup is complicated and the cost is high; (2) Feature points mainly rely on manual reading of the curve to judge, which is highly subjective and has poor repeatability; (3) It is difficult to establish a unified quantitative identification standard for rocks with different initial damage degrees.

[0005] In recent years, continuum damage mechanics has provided an effective theoretical framework for describing the evolution of rock damage. It can quantitatively characterize the development of internal microcracks through damage variables and establish the coupling relationship between stress, strain, and damage. However, related technologies are mostly focused on constitutive models and damage evolution law analysis, and rarely apply damage theory directly to the quantitative identification of characteristic stress thresholds. There is still a lack of an engineering method that can combine the characteristics of damage models to achieve analytical solutions for characteristic stress thresholds. Summary of the Invention

[0006] This application provides a method, device, electronic device, and storage medium for identifying rock characteristic stress thresholds, in order to solve the problems of high cost, strong subjectivity, poor repeatability, and limited applicability in related technologies, and to achieve accurate, objective, and efficient identification of key characteristic stresses such as crack initiation stress and crack damage stress in rocks.

[0007] To achieve the above objectives, the first aspect of this application proposes a method for identifying rock characteristic stress thresholds, comprising the following steps: Determine the initial damage variables of the rock sample to be tested; The peak stress and peak strain of the rock sample to be tested are determined, and based on the peak stress and peak strain of the rock sample to be tested, a damage model describing the relationship between initial damage and rock deformation and failure process is constructed according to the initial damage variables. Based on the damage model, a damage model curve is generated, and the crack initiation strain threshold and crack damage strain threshold are determined according to the damage model curve. Based on the preset rock axial stress-strain curve, the crack initiation stress and crack damage stress are obtained by mapping the crack initiation strain threshold and the crack damage strain threshold.

[0008] According to one embodiment of this application, determining the initial damage variable of the rock sample to be tested includes: Obtain the first elastic modulus of the rock sample under preset environmental conditions and the second elastic modulus of the rock sample to be tested; The initial damage variable is obtained based on the ratio of the second elastic modulus to the first elastic modulus.

[0009] According to one embodiment of this application, the initial damage variable is: ; in, d 0 represents the initial damage variable. E The first elastic modulus, E ( d 0) is the second elastic modulus.

[0010] According to one embodiment of this application, the damage model is: ; in, e In response to the current situation, D ( e , d 0) represents the damage variable considering the initial damage. m ( d 0) represents the shape parameter. e p ( d0) represents the peak strain of the rock sample to be tested. s p ( d 0) represents the peak stress of the rock sample to be tested.

[0011] According to one embodiment of this application, the crack initiation strain threshold and the crack damage strain threshold are respectively: ; in, e ci The crack initiation strain threshold is defined as follows. e cd The crack damage strain threshold is... e A The strain threshold at point A. L 2 represents the horizontal distance between point A and point T1. L 3 represents the horizontal distance between point A and point T2.

[0012] The rock characteristic stress threshold identification method proposed in this application constructs a damage model based on the initial damage variables, peak stress, and peak strain of the rock sample under test. A damage model curve is generated from the damage model, and the crack initiation strain threshold and crack damage strain threshold are determined based on the curve. The crack initiation stress and crack damage stress are then obtained by mapping the rock axial stress-strain curve. This solves the problems of high cost, strong subjectivity, poor repeatability, and limited applicability in related technologies, achieving accurate, objective, and efficient identification of key characteristic stresses such as crack initiation stress and crack damage stress in rocks.

[0013] To achieve the above objectives, a second aspect of this application provides a rock characteristic stress threshold identification device, comprising: The module determines the initial damage variables of the rock sample to be tested; The module is constructed to determine the peak stress and peak strain of the rock sample to be tested, and based on the peak stress and peak strain of the rock sample to be tested, a damage model describing the relationship between the initial damage and the rock deformation and failure process is constructed according to the initial damage variables. The identification module generates a damage model curve based on the damage model, determines the crack initiation strain threshold and the crack damage strain threshold according to the damage model curve, and obtains the crack initiation stress and the crack damage stress by mapping the crack initiation strain threshold and the crack damage strain threshold according to the preset rock axial stress-strain curve.

[0014] According to one embodiment of this application, the determining module is specifically used for: Obtain the first elastic modulus of the rock sample under preset environmental conditions and the second elastic modulus of the rock sample to be tested; The initial damage variable is obtained based on the ratio of the second elastic modulus to the first elastic modulus.

[0015] According to one embodiment of this application, the initial damage variable is: ; in, d 0 represents the initial damage variable. E The first elastic modulus, E ( d 0) is the second elastic modulus.

[0016] According to one embodiment of this application, the damage model is: ; in, e In response to the current situation, D ( e , d 0) represents the damage variable considering the initial damage. m ( d 0) represents the shape parameter. e p ( d 0) represents the peak strain of the rock sample to be tested. s p ( d 0) represents the peak stress of the rock sample to be tested.

[0017] According to one embodiment of this application, the crack initiation strain threshold and the crack damage strain threshold are respectively: ; in, e ci The crack initiation strain threshold is defined as follows. e cd The crack damage strain threshold is... e A The strain threshold at point A. L 2 represents the horizontal distance between point A and point T1. L 3 represents the horizontal distance between point A and point T2.

[0018] The rock characteristic stress threshold identification device proposed in this application constructs a damage model based on the initial damage variables, peak stress, and peak strain of the rock sample under test. A damage model curve is generated from the damage model, and the crack initiation strain threshold and crack damage strain threshold are determined based on the curve. The crack initiation stress and crack damage stress are then obtained by mapping the rock axial stress-strain curve. This solves the problems of high cost, strong subjectivity, poor repeatability, and limited applicability in related technologies, achieving accurate, objective, and efficient identification of key characteristic stresses such as crack initiation stress and crack damage stress in rocks.

[0019] To achieve the above objectives, a third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the rock characteristic stress threshold identification method as described in the above embodiments.

[0020] To achieve the above objectives, a fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the rock characteristic stress threshold identification method as described in the above embodiments.

[0021] To achieve the above objectives, a fifth aspect of this application provides a computer program product, which, when executed by a processor, implements the rock characteristic stress threshold identification method as described in the above embodiments.

[0022] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0023] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart of a rock characteristic stress threshold identification method provided according to an embodiment of this application; Figure 2 This is a schematic diagram of curve geometric approximation and characteristic strain threshold identification based on a damage model according to an embodiment of this application; Figure 3 This is a flowchart of a rock characteristic stress threshold identification method provided according to an embodiment of this application; Figure 4 This is a schematic diagram of the uniaxial compressive stress-strain curve of a freeze-thaw damaged rock sample according to an embodiment of this application; Figure 5This is a schematic diagram of the damage evolution curve corresponding to a damage evolution model provided according to an embodiment of this application; Figure 6 This is a schematic diagram of the volumetric strain versus crack volumetric strain curve of a damaged specimen according to an embodiment of this application. Figure 7 This is a block diagram of a rock characteristic stress threshold identification device provided according to an embodiment of this application; Figure 8 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application. Detailed Implementation

[0024] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0025] The following describes, with reference to the accompanying drawings, a method, apparatus, electronic device, and storage medium for identifying rock characteristic stress thresholds according to embodiments of this application. First, the method for identifying rock characteristic stress thresholds according to embodiments of this application will be described with reference to the accompanying drawings.

[0026] Figure 1 This is a flowchart of a rock characteristic stress threshold identification method according to an embodiment of this application.

[0027] like Figure 1 As shown, the rock characteristic stress threshold identification method includes the following steps: In step S101, the initial damage variable of the rock sample to be tested is determined.

[0028] Optionally, in some embodiments, determining the initial damage variable of the rock sample to be tested includes: obtaining the first elastic modulus of the rock sample under preset environmental conditions and the second elastic modulus of the rock sample to be tested; and obtaining the initial damage variable based on the ratio of the second elastic modulus to the first elastic modulus.

[0029] Optionally, in some embodiments, the initial damage variable is: ; in, d 0 represents the initial damage variable. E The first elastic modulus, E ( d 0) is the second elastic modulus.

[0030] The initial damage variable refers to the initial parameters of the degree of defects such as microcracks and pores naturally existing inside the rock sample under test, when it is not subjected to external force and is only affected by its own formation process or a preset environment. The preset environmental conditions can be conditions pre-set by the user, conditions obtained through a limited number of experiments, or conditions obtained through a limited number of computer simulations. The first elastic modulus refers to the elastic modulus obtained by a complete rock sample without initial damage under the preset environmental conditions. The second elastic modulus refers to the elastic modulus obtained by the rock sample under the same preset environmental conditions as the rock sample.

[0031] Specifically, in this embodiment, a rock sample under preset environmental conditions is selected as the initial damage reference sample. The initial damage of the reference sample is defined as zero, and the first elastic modulus of the reference sample is obtained. E and the second elastic modulus of the rock sample to be tested E ( d 0). The initial damage reference datum can be flexibly selected according to engineering needs. Changing the reference datum only causes the damage model to stretch and translate along the vertical axis, without altering the characteristics of the damage model curve's variation in the horizontal strain direction, thus not affecting... e ci , e cd and corresponding s ci , s cd The recognition results.

[0032] The initial damage variable of the test sample is defined based on the difference between the first elastic modulus of the reference specimen and the second elastic modulus of the test specimen. d 0. To achieve a unified quantitative expression of initial rock damage under different environmental conditions, the initial damage variable of the test sample is determined based on the ratio of the second elastic modulus to the first elastic modulus. The initial damage variable... d 0 represents the relative damage level of the test sample relative to the reference rock sample.

[0033] In step S102, the peak stress and peak strain of the rock sample to be tested are determined, and based on the peak stress and peak strain of the rock sample to be tested, a damage model describing the relationship between the initial damage and the rock deformation and failure process is constructed according to the initial damage variables.

[0034] Optionally, in some embodiments, the damage model is: ; in, e In response to the current situation, D ( e , d0) represents the damage variable considering the initial damage. m ( d 0) represents the shape parameter. e p ( d 0) represents the peak strain of the rock sample to be tested. s p ( d 0) represents the peak stress of the rock sample to be tested.

[0035] The peak stress of the rock sample under test refers to the peak stress obtained from the stress-strain curve. The peak strain of the rock sample under test refers to the peak strain obtained from the stress-strain curve.

[0036] Specifically, this application's embodiments, based on the assumptions of continuous damage mechanics and equivalent strain, introduce the peak stress of the rock sample to be tested. s p and the peak strain of the rock sample to be tested e p Construct a system that considers initial damage variables d 0 and strain e The functional relationship between them yields a damage model describing the connection between the initial damage variable and the rock deformation and failure process. D ( e , d 0), where, D ( e , d 0) By combining the stress-strain relationship with the equivalent strain assumption, peak stress is utilized. s p With peak strain e p The damage variable is normalized so that it remains basically constant in the initial stage of deformation and gradually approaches the maximum value after approaching the peak stress.

[0037] The initial and final segments of this damage model are approximately horizontal, while the middle segment is horizontal. S The shapes correspond to the "no-damage stage", "rapid damage evolution stage" and "complete damage stage", respectively.

[0038] In step S103, a damage model curve is generated based on the damage model, and the crack initiation strain threshold and crack damage strain threshold are determined according to the damage model curve. Based on the preset rock axial stress-strain curve, the crack initiation stress and crack damage stress are obtained by mapping the crack initiation strain threshold and crack damage strain threshold.

[0039] Optionally, in some embodiments, the crack initiation strain threshold and the crack damage strain threshold are respectively: ; in, e ci The crack initiation strain threshold. e cd The crack damage strain threshold. e A The strain threshold at point A. L 2 represents the horizontal distance between point A and point T1. L 3 represents the horizontal distance between point A and point T2.

[0040] The crack initiation strain threshold, determined by the damage model curve, is the critical axial strain value at which microcracks within the rock begin to initiate and propagate from the initial defect. The crack damage strain threshold, determined by the damage model curve, is the critical axial strain value at which microcracks within the rock begin to rapidly propagate and interconnect.

[0041] Specifically, in this embodiment, a damage model curve is generated based on a damage model. The initial stage of the damage model curve is an approximately horizontal straight line, corresponding to the deformation stage where the rock has not suffered significant damage; the final stage is an approximately horizontal straight line, corresponding to the stage where the rock damage reaches saturation and the bearing capacity is completely lost; the middle stage is an S-shaped curve, corresponding to the deformation and failure process from stable crack propagation to unstable crack propagation.

[0042] like Figure 2 As shown, Figure 2 This is a schematic diagram illustrating curve geometric approximation and characteristic strain threshold identification based on a damage model, according to an embodiment of this application. As shown in the diagram, the damage curve is divided into two segments within a certain strain range: in the strain interval […]. e ci , e cd Within this section, the embodiments of this application use a circle with the center as... C An arc of radius R Damage model D ( e , d The middle section curve of 0) S The curve is approximated; within the strain range [ e cd , e M Within this section, the embodiments of this application use the midpoint of the damage variable value range. M Based on this, construct through M Tangent at a point T 2 M A linear approximation is applied to the curve. This approximates the curve using the midpoint of the damage variable's range in the damage model. M Given a point, determine the path through it. MThe point and the tangent line that is tangent to the damage model curve T 2 M The tangent point is M Initial damage extension segment T 1A and T 2 M Intersection at the initial damage point A ( e A , d 0), point T 1 is a circle C With a straight line T 1 A The point of tangency; line AC is the angle bisector of ∠T1AT2, and point B is the point where line AC intersects ∠T1AT2. Intersection point; the damage evolution curve is approximated by the following four segments: initial damage segment, circular arc segment, etc. straight line segment T 2 M , and the damage saturation segment.

[0043] This application embodiment uses the arc tangent point T 1. T 2 and point A , M The geometric relationship between them is transformed into a distance relationship on the strain axis, thereby obtaining e ci and e cd The analytical expression is then derived. Further, in this embodiment, based on the geometric relationship between the damage model curve, the arc, and the tangents, the tangent points T1 and T2 between the arc and the two tangents are determined. Through geometric constraints of the angle bisector, segment length, and strain coordinates, the crack initiation strain threshold is analytically solved. e ci and crack damage strain threshold e cd .

[0044] This application embodiment obtains a preset rock axial stress-strain curve and sets a crack initiation strain threshold. e ci and crack damage strain threshold e cd Mapping to the corresponding axial stress level yields the crack initiation stress. s ci and crack damage stress s cd Two characteristic stress thresholds are used to identify the characteristic stress thresholds of the rock. Specifically, the embodiments of this application rely only on the preset axial stress-strain curve of the rock, and can determine the crack initiation stress without collecting radial strain data. s ci and crack damage stress scd The identification.

[0045] To facilitate a better understanding of the rock characteristic stress threshold identification method proposed in this application by those skilled in the art, further explanation is provided below with reference to specific embodiments.

[0046] On the one hand, such as Figure 3 As shown, Figure 3 This is a flowchart of a rock characteristic stress threshold identification method according to an embodiment of this application, which includes the following steps: S301, the experiment obtained the uniaxial compressive stress-strain curve of the rock.

[0047] S302, Select the initial damage reference standard.

[0048] S303, Construct a damage evolution model.

[0049] S304, Geometric approximation of the damage evolution model.

[0050] S305, solve for the characteristic strain of crack initiation and the characteristic strain of crack damage.

[0051] S306 represents the crack initiation stress and crack damage characteristic stress.

[0052] Therefore, this embodiment first selects a rock sample under certain environmental conditions as the initial damage reference standard. Based on the difference in elastic modulus between the reference sample and the test sample, the initial damage variable of the test sample is calculated. Based on the assumptions of continuous damage mechanics and equivalent strain, a damage evolution model considering the influence of initial damage is established to obtain the functional relationship between the damage variable and strain. Then, using the axial stress-strain curve and mechanical parameters such as peak stress and peak strain obtained from the experiment, the damage model curve is geometrically approximated within a predetermined strain range using circular arcs and tangents, and the crack initiation strain threshold and crack damage strain threshold are obtained accordingly. Finally, through the stress-strain curve, the strain threshold is converted into two important characteristic stress thresholds: crack initiation stress and crack damage stress. Compared with the traditional crack volumetric strain method, this embodiment only requires axial stress-strain data to achieve analytical identification of characteristic stress thresholds, while avoiding subjective errors caused by manual graph reading, reducing the complexity of experimental data acquisition, and the characteristic stress identification results are not affected by the selection of the initial damage reference standard. It is suitable for quantitative evaluation of deformation and failure of rocks with different initial damage degrees and long-term stability analysis in engineering projects.

[0053] On the other hand, in this embodiment, two sandstone samples were selected based on the P-wave velocity, which was between 2.4 km / s and 2.5 km / s. The samples were cylindrical standard specimens with a diameter of 50 mm and a height of 100 mm. One was selected as the reference rock sample, and the other underwent freeze-thaw damage treatment. According to the freeze-thaw cycle test method recommended by ISRM (International Society for Rock Mechanics and Rock Engineering), the freeze-thaw conditions were set as follows: saturation > 97%, freezing temperature -20℃ (4 h), thawing temperature 20℃ (4 h), and the number of freeze-thaw cycles set to 25. Stress-strain curves of the reference sample and the damaged sample were obtained through uniaxial compression tests, as shown below. Figure 4 As shown, Figure 4 This is a schematic diagram of the uniaxial compressive stress-strain curve of a freeze-thaw damaged rock sample according to an embodiment of this application. The elastic modulus (i.e., the first elastic modulus) of the reference sample is obtained through the stress-strain curve. The elastic modulus of the damaged specimen (i.e., the second elastic modulus). Peak strain of the loss specimen Peak stress of the loss specimen The initial damage variable was calculated using the formula. .

[0054] This application's embodiments construct a damage evolution model that considers initial damage: ; like Figure 5 As shown, Figure 5 This is a schematic diagram of the damage evolution curve corresponding to a damage evolution model provided according to an embodiment of this application. The embodiment of this application performs a geometric approximation and analytical solution on the damage evolution curve. Based on the geometric relationship, the characteristic strain thresholds, namely the crack initiation strain threshold and the crack damage strain threshold, can be obtained: ; in, εA for A The x-coordinate of a point can be obtained by the following formula: ; in, L 2. L 3 are respectively A Point and T 1 point and T The horizontal distance between two points is calculated using the following formula: ; in, R The radius of the arc, For ∠T 2 AD The calculation formula is as follows:

[0055] ; in, L 1=| AB The calculation formula is as follows: ; Therefore, the characteristic strain threshold can be obtained based on the above formula: ; ; Based on the stress-strain curve, the characteristic strain is mapped to the characteristic stress, and the following can be obtained: ; .

[0056] To compare and analyze the identification results, this application also employs the crack volumetric strain method to identify the characteristic stresses of the same specimen. For example... Figure 6 As shown, Figure 6 This is a schematic diagram of the volumetric strain versus crack volumetric strain curve of a damaged specimen according to an embodiment of this application. The characteristic strain can be obtained by manually interpreting the curve. , Characteristic stresses can be obtained by mapping stress-strain curves. , A comparison with the above results shows that the characteristic stresses identified by the two methods are consistent.

[0057] Furthermore, this application is applicable to rock materials with different initial damage levels under different environmental conditions such as freeze-thaw cycles, high temperature and high pressure, and chemical corrosion, for evaluating the rock engineering stability and long-term strength.

[0058] Therefore, the data requirements of this application embodiment are simple, relying only on the axial stress-strain curve and basic mechanical parameters, without the need to collect radial strain data, which significantly reduces the complexity and cost of the test system. The characteristic strain threshold is obtained by analytical solution through the damage model and geometric relationship, eliminating the need for manual interpretation of points on volumetric strain or other curves, reducing errors caused by subjective human judgment, and improving the objectivity and repeatability of the identification results. It is applicable to rocks with different initial damage degrees, and the initial damage reference benchmark can be flexibly selected, which mathematically represents the stretching and translation of the damage model in the longitudinal direction. The characteristic stress identification of this application embodiment depends on the change characteristics of the curve in the transverse strain direction, so the selection of the reference benchmark does not affect the final identification result, and it is applicable to rock materials under different environmental damage conditions. It has high engineering application value. Compared with traditional CVS, the identification results of crack initiation stress and crack damage stress in this application embodiment have high consistency, while avoiding complex data collection and manual interpretation processes, providing new theoretical tools and technical means for long-term strength assessment, stability analysis and safety factor determination in rock engineering.

[0059] It should be noted that the crack volumetric strain method is only used as a comparative analysis method, and the radial strain data required by it is not a necessary input for this application. The characteristic stress identification process of this application is entirely based on axial stress-strain data.

[0060] The rock characteristic stress threshold identification method proposed in this application constructs a damage model based on the initial damage variables, peak stress, and peak strain of the rock sample under test. A damage model curve is generated from the damage model, and the crack initiation strain threshold and crack damage strain threshold are determined based on the curve. The crack initiation stress and crack damage stress are then obtained by mapping the rock axial stress-strain curve. This solves the problems of high cost, strong subjectivity, poor repeatability, and limited applicability in related technologies, achieving accurate, objective, and efficient identification of key characteristic stresses such as crack initiation stress and crack damage stress in rocks.

[0061] Next, referring to the accompanying drawings, a rock characteristic stress threshold identification device proposed according to an embodiment of this application is described.

[0062] Figure 7 This is a block diagram of a rock characteristic stress threshold identification device according to an embodiment of this application.

[0063] like Figure 7 As shown, the rock characteristic stress threshold identification device 10 includes: a determination module 100, a construction module 200, and an identification module 300.

[0064] Determine module 100 to determine the initial damage variables of the rock sample to be tested; Module 200 is constructed to determine the peak stress and peak strain of the rock sample to be tested, and based on the peak stress and peak strain of the rock sample to be tested, a damage model describing the relationship between the initial damage and the rock deformation and failure process is constructed according to the initial damage variables. The identification module 300 generates a damage model curve based on the damage model, determines the crack initiation strain threshold and the crack damage strain threshold based on the damage model curve, and obtains the crack initiation stress and the crack damage stress based on the preset rock axial stress-strain curve and the crack initiation strain threshold and the crack damage strain threshold.

[0065] According to one embodiment of this application, the determining module 100 is specifically used for: Obtain the first elastic modulus of the rock sample under preset environmental conditions and the second elastic modulus of the rock sample to be tested; The initial damage variable is obtained based on the ratio of the second elastic modulus to the first elastic modulus.

[0066] According to one embodiment of this application, the initial damage variable is: ; in, d 0 represents the initial damage variable. E The first elastic modulus, E ( d 0) is the second elastic modulus.

[0067] According to one embodiment of this application, the damage model is as follows: ; in, e In response to the current situation, D ( e , d 0) represents the damage variable considering the initial damage. m ( d 0) represents the shape parameter. e p ( d 0) represents the peak strain of the rock sample to be tested. s p ( d 0) represents the peak stress of the rock sample to be tested.

[0068] According to one embodiment of this application, the crack initiation strain threshold and the crack damage strain threshold are respectively: ; in, e ci The crack initiation strain threshold. e cdThe crack damage strain threshold. e A The strain threshold at point A. L 2 represents the horizontal distance between point A and point T1. L 3 represents the horizontal distance between point A and point T2.

[0069] It should be noted that the foregoing explanation of the rock characteristic stress threshold identification method embodiment also applies to the rock characteristic stress threshold identification device of this embodiment, and will not be repeated here.

[0070] The rock characteristic stress threshold identification device proposed in this application constructs a damage model based on the initial damage variables, peak stress, and peak strain of the rock sample under test. A damage model curve is generated from the damage model, and the crack initiation strain threshold and crack damage strain threshold are determined based on the curve. The crack initiation stress and crack damage stress are then obtained by mapping the rock axial stress-strain curve. This solves the problems of high cost, strong subjectivity, poor repeatability, and limited applicability in related technologies, achieving accurate, objective, and efficient identification of key characteristic stresses such as crack initiation stress and crack damage stress in rocks.

[0071] Figure 8 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. The electronic device may include: The memory 801, the processor 802, and the computer program stored on the memory 801 and capable of running on the processor 802.

[0072] When the processor 802 executes the program, it implements the rock feature stress threshold identification method provided in the above embodiments.

[0073] Furthermore, electronic devices also include: Communication interface 803 is used for communication between memory 801 and processor 802.

[0074] The memory 801 is used to store computer programs that can run on the processor 802.

[0075] The memory 801 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.

[0076] If the memory 801, processor 802, and communication interface 803 are implemented independently, then the communication interface 803, memory 801, and processor 802 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 8 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0077] Optionally, in a specific implementation, if the memory 801, processor 802, and communication interface 803 are integrated on a single chip, then the memory 801, processor 802, and communication interface 803 can communicate with each other through an internal interface.

[0078] The processor 802 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement embodiments of the present invention.

[0079] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the rock characteristic stress threshold identification method described above.

[0080] This application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps in any of the rock characteristic stress threshold identification method embodiments described above.

[0081] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0082] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0083] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for identifying rock characteristic stress thresholds, characterized in that, include: Determine the initial damage variables of the rock sample to be tested; The peak stress and peak strain of the rock sample to be tested are determined, and based on the peak stress and peak strain of the rock sample to be tested, a damage model describing the relationship between initial damage and rock deformation and failure process is constructed according to the initial damage variables. Based on the damage model, a damage model curve is generated, and the crack initiation strain threshold and crack damage strain threshold are determined according to the damage model curve. Based on the preset rock axial stress-strain curve, the crack initiation stress and crack damage stress are obtained by mapping the crack initiation strain threshold and the crack damage strain threshold.

2. The method according to claim 1, characterized in that, The determination of the initial damage variable of the rock sample to be tested includes: Obtain the first elastic modulus of the rock sample under preset environmental conditions and the second elastic modulus of the rock sample to be tested; The initial damage variable is obtained based on the ratio of the second elastic modulus to the first elastic modulus.

3. The method according to claim 2, characterized in that, The initial damage variable is: ； in, d 0 represents the initial damage variable. E The first elastic modulus, E ( d 0) is the second elastic modulus.

4. The method according to claim 3, characterized in that, The damage model is as follows: ； in, ε In response to the current situation, D ( ε , d 0) represents the damage variable considering the initial damage. m ( d 0) represents the shape parameter. ε p ( d 0) represents the peak strain of the rock sample to be tested. σ p ( d 0) represents the peak stress of the rock sample to be tested.

5. The method according to claim 1, characterized in that, The crack initiation strain threshold and the crack damage strain threshold are respectively: ； in, ε ci The crack initiation strain threshold is defined as follows. ε cd The crack damage strain threshold is... ε A The strain threshold at point A. L 2 represents the horizontal distance between point A and point T1. L 3 represents the horizontal distance between point A and point T2.

6. A rock characteristic stress threshold identification device, characterized in that, include: The module determines the initial damage variables of the rock sample to be tested; The module is constructed to determine the peak stress and peak strain of the rock sample to be tested, and based on the peak stress and peak strain of the rock sample to be tested, a damage model describing the relationship between the initial damage and the rock deformation and failure process is constructed according to the initial damage variables. The identification module generates a damage model curve based on the damage model, determines the crack initiation strain threshold and the crack damage strain threshold according to the damage model curve, and obtains the crack initiation stress and the crack damage stress by mapping the crack initiation strain threshold and the crack damage strain threshold according to the preset rock axial stress-strain curve.

7. The apparatus according to claim 6, characterized in that, The determining module is specifically used for: Obtain the first elastic modulus of the rock sample under preset environmental conditions and the second elastic modulus of the rock sample to be tested; The initial damage variable is obtained based on the ratio of the second elastic modulus to the first elastic modulus.

8. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the rock characteristic stress threshold identification method as described in any one of claims 1-5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the rock characteristic stress threshold identification method as described in any one of claims 1-5.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the rock characteristic stress threshold identification method as described in any one of claims 1-5.

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