Brittleness evaluation method and device based on uniaxial compression damage evolution characteristics of rock

Abstract

The application discloses a brittle evaluation method and device based on uniaxial compression damage evolution characteristics of rock, and belongs to the technical field of rock mechanics. The method comprises the following steps: determining a rock damage evolution curve by using a deformation modulus attenuation method based on a stress-strain curve; determining a peak strain according to a peak stress of the stress-strain curve, and determining a pre-peak damage variable corresponding to the peak strain according to the rock damage evolution curve; fitting the rock damage evolution curve to obtain a theoretical damage evolution equation of a rock sample; determining a maximum damage evolution rate and a strain value corresponding to the maximum damage evolution rate according to a first derivative of the theoretical damage evolution equation; and calculating a brittle evaluation index of the rock sample by using a formula. The method starts from the damage evolution characteristics of the whole process of rock compression damage, comprehensively considers the pre-peak damage variable of rock, the post-peak damage evolution rate and the peak strain, establishes the brittle evaluation index of rock, and has rationality and reliability, and can be used in engineering practice.

Description

Technical Field

[0001] This invention relates to the field of rock mechanics, and in particular to a brittleness evaluation method and apparatus based on the evolution characteristics of uniaxial compression damage in rocks. Background Technology

[0002] Brittleness is one of the important mechanical properties of rocks. It refers to the property of rocks to suddenly break and lose their bearing capacity under the action of external forces with very small deformation. Quantitative evaluation of rock brittleness can provide an important reference for predicting the occurrence of rockbursts in deep-buried high-stress tunnels and judging the tendency of rockbursts.

[0003] Currently, rock brittleness evaluation indices are mainly established based on rock strength parameters, deformation parameters, mineral composition, stress-strain curve morphology, and energy evolution processes. Among these, the rock brittleness evaluation index based on the full stress-strain curve is the most widely used, intuitive, and reliable. However, some brittleness evaluation methods based on the full stress-strain curve only consider the post-peak deformation mechanical properties and stress drop rate, or only consider the pre-peak deformation mechanical properties, which affects the accuracy of rock brittleness characterization. Although some evaluation methods consider the influence of stress or deformation characteristics on the degree of brittleness during the process from pre-peak crack initiation to peak value, there is still no standard method for determining the crack initiation stress. The determination of the initiation stress using the crack volumetric strain curve is greatly affected by the rock's own properties. The completeness of the post-peak stress-strain curve is greatly affected by experimental conditions, such as the stiffness of the testing machine, loading rate, and specimen geometry. In addition, the selection of the residual strength starting point also affects the calculation results of the post-peak brittleness index. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, the present invention provides the following technical solution.

[0005] The first aspect of this invention provides a brittleness evaluation method based on the uniaxial compression damage evolution characteristics of rocks, comprising:

[0006] Obtain the stress-strain curves of uniaxial compression tests on rock specimens;

[0007] Based on the stress-strain curve, the deformation modulus attenuation method is used to determine the rock damage evolution curve;

[0008] The peak strain is determined based on the peak stress of the stress-strain curve, and the damage variable value corresponding to the peak strain is determined based on the rock damage evolution curve.

[0009] The theoretical damage evolution equation of the rock sample is obtained by fitting the rock damage evolution curve.

[0010] The first derivative of the theoretical damage evolution equation is obtained, and the maximum damage evolution rate and its corresponding strain value are determined based on the peak point of the first derivative.

[0011] The brittleness evaluation index B of the rock sample is calculated using the following formula. DE :

[0012]

[0013] In the formula, ε cc The crack closure strain is determined by the intersection of the backward extension of the elastic stage of the stress-strain curve and the horizontal axis; ε p D represents the peak strain. p D represents the damage variable value corresponding to the peak strain. m ′ represents the maximum damage evolution rate; ε m B represents the strain value corresponding to the maximum damage evolution rate. DE B is an index for evaluating the brittleness of rock samples. pre B is an evaluation index for the pre-peak brittleness of rock samples. post It serves as an evaluation index for the post-peak brittleness of rock samples.

[0014] Preferably, the determination of the rock damage evolution curve based on the stress-strain curve and using the deformation modulus attenuation method includes:

[0015] The damage variable is represented by the following formula. in, Let be the slope of the line connecting any point on the stress-strain curve to the origin of the coordinate system, and E be the elastic modulus.

[0016] The rock damage evolution curve is established using damage variables and their corresponding strains.

[0017] Preferably, the theoretical damage evolution equation of the rock sample is obtained by fitting the rock damage evolution curve using the following formula:

[0018]

[0019] In the formula, D is the damage variable; a and r are fitting parameters; and L is strain.

[0020] Preferably, the method further includes the step of: obtaining the first derivative of the theoretical damage evolution equation using the following formula:

[0021]

[0022] A second aspect of the present invention provides a brittleness evaluation device based on the uniaxial compression damage evolution characteristics of rocks, comprising:

[0023] The stress-strain curve acquisition module is used to acquire the stress-strain curve of a rock specimen in a uniaxial compression test.

[0024] The rock damage evolution curve determination module is used to determine the rock damage evolution curve based on the stress-strain curve and using the deformation modulus attenuation method.

[0025] The first parameter determination module is used to determine the peak strain based on the peak stress point of the stress-strain curve, and to determine the damage variable value corresponding to the peak strain based on the rock damage evolution curve.

[0026] The fitting module is used to fit the rock damage evolution curve to obtain the theoretical damage evolution equation of the rock sample.

[0027] The second parameter determination module is used to calculate the first derivative of the theoretical damage evolution equation and determine the maximum damage evolution rate and its corresponding strain value based on the peak point of the first derivative.

[0028] The brittleness evaluation index calculation module is used to calculate the brittleness evaluation index B of the rock sample using the following formula. DE :

[0029]

[0030] In the formula, ε cc The crack closure strain is determined by the intersection of the backward extension of the elastic stage of the stress-strain curve and the horizontal axis; ε p D represents the peak strain. p D represents the damage variable value corresponding to the peak strain. m ′ represents the maximum damage evolution rate; ε m B represents the strain value corresponding to the maximum damage evolution rate. DE B is an index for evaluating the brittleness of rock samples. pre B is an evaluation index for the pre-peak brittleness of rock samples. post It serves as an evaluation index for the post-peak brittleness of rock samples.

[0031] Preferably, in the rock damage evolution curve determination module, the determination of the rock damage evolution curve based on the stress-strain curve and using the deformation modulus attenuation method includes:

[0032] The damage variable is represented by the following formula. in, Let be the slope of the line connecting any point on the stress-strain curve to the origin of the coordinate system, and E be the elastic modulus.

[0033] The rock damage evolution curve is established using damage variables and their corresponding strains.

[0034] Preferably, in the fitting module, the theoretical damage evolution equation of the rock sample is obtained by fitting the rock damage evolution curve using the following formula:

[0035]

[0036] In the formula, D is the damage variable; a and r are fitting parameters; and L is strain.

[0037] Preferably, the fitting module is further configured to calculate the first derivative of the theoretical damage evolution equation using the following formula:

[0038]

[0039] The present invention also provides a memory that stores multiple instructions for implementing the brittleness evaluation method based on the uniaxial compression damage evolution characteristics of rocks as described in the first aspect.

[0040] The present invention also provides an electronic device, including a processor and a memory connected to the processor, the memory storing a plurality of instructions which can be loaded and executed by the processor to enable the processor to perform the brittleness assessment method based on the uniaxial compression damage evolution characteristics of rocks as described in the first aspect.

[0041] The beneficial effects of this invention are as follows: The brittleness evaluation method and apparatus based on the uniaxial compression damage evolution characteristics of rocks provided by this invention establish a brittleness evaluation index for rocks from the perspective of damage evolution characteristics throughout the entire process of rock compression failure. This index comprehensively considers factors such as pre-peak damage variables, post-peak damage evolution rate, and peak strain. Through theoretical analysis and experimental verification, the results show that the brittleness evaluation index provided by this invention has good rationality and reliability for rock brittleness evaluation and can be used in engineering practice. Attached Figure Description

[0042] Figure 1 The stress-strain curve of uniaxial compressive stress in rock;

[0043] Figure 2 This is a schematic flowchart of the brittleness evaluation method based on the uniaxial compression damage evolution characteristics of rocks as described in this invention.

[0044] Figure 3 The typical uniaxial compressive stress-strain curve of rock and the corresponding rock damage evolution curve characterized by the deformation modulus attenuation method are shown.

[0045] Figure 4 The image shows the rock damage evolution curve and the corresponding rock damage evolution rate curve, characterized by the Logistic growth model.

[0046] Figure 5(a) is a schematic diagram of the process of transforming the rock uniaxial compressive stress-strain curve I, which considers the nonlinear deformation stage of the initial compaction of the rock, into the rock uniaxial compressive stress-strain curve II, which does not consider the nonlinear deformation stage of the initial compaction of the rock. (b) is the rock uniaxial compressive stress-strain curve without considering the nonlinear deformation stage of the initial compaction of the rock.

[0047] Figure 6 The uniaxial compressive stress-strain curves for each specimen are shown.

[0048] Figure 7 This is a schematic diagram showing the theoretical damage evolution curves and actual calculated damage results for each sample.

[0049] Figure 8 This is a schematic diagram of the functional structure of the brittleness evaluation device based on the uniaxial compression damage evolution characteristics of rocks according to the present invention. Detailed Implementation

[0050] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0051] The stress-strain curves following rock peaks often exhibit a sudden stress drop phase and a gradual stress drop phase, such as... Figure 1 As shown ( Figure 1 In the diagram, the horizontal axis represents strain, and the vertical axis represents stress, namely the brittle drop stage and the strain softening stage. From Figure 1 It can be seen that the stress drop phase and the stress deceleration phase of the stress-strain curve correspond to the damage acceleration phase and the damage deceleration phase, respectively. That is, in the stress drop phase, microcracks within the rock rapidly merge and connect to form a macroscopic fracture surface. This fracturing process represents the rapid and concentrated release of energy accumulated before the rock peak, resulting in a sharp increase in damage variables. Therefore, it is reasonable to use the deformation mechanics characteristics of the stress drop phase (damage acceleration phase) to characterize the degree of brittle fracture after the rock peak. Furthermore, methods for constructing brittleness evaluation indicators from the perspective of rock damage evolution characteristics are currently relatively rare.

[0052] Example 1

[0053] like Figure 2As shown, this embodiment of the invention provides a brittleness evaluation method based on the uniaxial compression damage evolution characteristics of rock, including: S101, obtaining the stress-strain curve of the uniaxial compression test of the rock sample; S102, determining the rock damage evolution curve based on the stress-strain curve using the deformation modulus attenuation method; S103, determining the peak strain based on the peak stress of the stress-strain curve, and determining the damage variable value corresponding to the peak strain based on the rock damage evolution curve; S104, fitting the rock damage evolution curve to obtain the theoretical damage evolution equation of the rock sample; S105, calculating the first derivative of the theoretical damage evolution equation, and determining the maximum damage evolution rate and its corresponding strain value based on the peak point of the first derivative; S106, calculating the brittleness evaluation index B of the rock sample using the following formula. DE :

[0054]

[0055] In the formula, ε cc The crack closure strain is determined by the intersection of the backward extension of the elastic stage of the stress-strain curve and the horizontal axis; ε p D represents the peak strain. p D represents the damage variable value corresponding to the peak strain. m ′ represents the maximum damage evolution rate; ε m B represents the strain value corresponding to the maximum damage evolution rate. DE B is an index for evaluating the brittleness of rock samples. pre B is an evaluation index for the pre-peak brittleness of rock samples. post It serves as an evaluation index for the post-peak brittleness of rock samples.

[0056] In the specific implementation process, rock samples of different lithologies can be retrieved from the engineering site, then processed into standard cylindrical specimens with a height of 100 mm and a diameter of 50 mm, and uniaxial compression tests can be performed on each specimen to obtain the stress-strain curve of the rock specimen.

[0057] like Figure 3 The typical uniaxial compressive stress-strain curve of the rock shown (strain L on the horizontal axis and stress σ on the vertical axis) roughly includes four stages: elastic deformation, plastic deformation, post-peak stress brittle drop, and strain softening (represented by stages I, II, III, and IV in the figure). To describe the damage deterioration process of the rock during compressive deformation, the damage variable D of the rock can be characterized by the deformation modulus attenuation method, i.e.: in, Let L be the slope of the line connecting any point on the stress-strain curve to the origin of the coordinate system, and E be the elastic modulus. Therefore, we obtain the rock damage evolution curve during a typical rock compression process corresponding to the stress-strain curve (the horizontal axis is strain L, and the vertical axis is damage variable D). From... Figure 3 As can be seen from the figure, the rock damage evolution curve generally shows an "S" shaped development trend. The damage process can be roughly divided into four stages: initial no damage, damage onset, damage acceleration, and damage deceleration (represented by I, II, III, and IV in the figure, respectively). These correspond to the four stages of elastic deformation, plastic deformation, post-peak stress brittle drop, and strain softening process in the rock compression deformation process.

[0058] The logistic growth model is a commonly used biological model that describes the "S"-shaped curve of a population's evolution from its initial stage, rapid development, slowing growth, and gradual stabilization. Therefore, in this invention, the logistic growth model can be used to fit the rock damage evolution curve to obtain the theoretical damage evolution equation for the rock sample. The rock damage evolution model based on the logistic growth model is as follows:

[0059]

[0060] In the formula: D is the damage variable; a and r are model parameters obtained through fitting; L is the strain.

[0061] Taking the first derivative of the obtained rock damage evolution equation, we can obtain the following expression for the rock damage evolution rate:

[0062]

[0063] The rock damage evolution curve and the corresponding rock damage evolution rate curve characterized by the Logistic growth model can be seen as follows: Figure 4 As shown. From Figure 4 It can be seen that the rock damage evolution process characterized by the Logistic growth model can also be roughly divided into four stages: initial no damage, damage onset, damage acceleration, and damage deceleration. This is consistent with the rock damage evolution process characterized by the elastic modulus decay method. The rock damage evolution rate first increases and then decreases with increasing strain, following a standard normal distribution. The peak of the rock damage evolution rate curve is the maximum rock damage evolution rate, which can be denoted as D. m ′.

[0064] During compression, brittle rocks exhibit relatively small pre-peak plastic deformation, meaning a smaller pre-peak damage variable. This leads to a sudden increase in post-peak damage variable, making crack propagation and penetration more likely, resulting in a faster damage evolution rate and a greater maximum damage evolution rate. Conversely, ductile rocks show significant pre-peak plastic deformation, indicating pronounced pre-peak damage evolution. Overall, they exhibit gradual damage and failure, with a slower post-peak damage evolution rate and a smaller maximum damage evolution rate. When the external force on the rock exceeds the pre-peak initiation stress, cracks begin to initiate and propagate stably, gradually increasing the damage variable. The lower the pre-peak damage variable, the smaller the pre-peak plastic deformation of the rock, the lower the degree of crack propagation, the less energy dissipated, and the higher the pre-peak elastic strain energy storage rate. This results in more elastic energy being released during post-peak failure, enhancing the post-peak autonomous fracture capability and crack propagation capability, and thus exhibiting a higher level of brittleness. Conversely, the higher the pre-peak damage variable, the stronger the pre-peak plastic deformation capability of the rock, the more complete the crack propagation and the more energy consumed. Correspondingly, the lower the pre-peak elastic strain energy storage rate, the less elastic energy can be released during post-peak failure, thus exhibiting a progressive low-brittleness failure characteristic.

[0065] Based on the above analysis, this invention establishes a brittleness evaluation index for rocks from the perspective of damage evolution characteristics throughout the entire process of rock compression failure. This index comprehensively considers pre-peak damage variables, post-peak damage evolution rate, and peak strain, and its expression is as follows:

[0066]

[0067] Where: ε cc The crack closure strain can be determined by the intersection of the backward extension of the linear elastic stage with the transverse axis; ε p D represents the peak strain. p D represents the damage variable value corresponding to the peak strain. m ′ represents the maximum damage evolution rate; ε m B represents the strain value corresponding to the maximum damage evolution rate. DE B is an index for evaluating the brittleness of rock samples. pre B is an evaluation index for the pre-peak brittleness of rock samples. post It serves as an evaluation index for the post-peak brittleness of rock samples.

[0068] The brittleness of the rock sample can be evaluated using a brittleness evaluation index. The method provided in this invention comprehensively considers the pre-peak damage variable, peak deformation, and post-peak damage evolution rate. Analysis of this index shows that the damage variable at the peak is inversely proportional to brittleness, i.e., D... p The larger the value, the lower the brittleness; D p The smaller the value, the greater the brittleness. Since the maximum value of the rock damage variable is 1, therefore 1-D pPeak strain is directly proportional to brittleness. Peak strain is also inversely proportional to rock brittleness; generally, a smaller peak strain at rock failure indicates greater brittleness. In engineering practice, rock masses subjected to various disturbances will contain initial damage such as microcracks and microfractures, leading to crack closure during compressive deformation. Figure 5 As shown in (a), the uniaxial compressive stress-strain curve of rock is typically curve I in (a). Curve I includes the initial nonlinear deformation stage of rock compaction, the elastic deformation stage, the plastic deformation stage, and the post-peak failure stage. If the initial nonlinear deformation stage of rock compaction is not considered, i.e., the rock directly enters the elastic deformation stage after being loaded, then it is as shown by curve II in (a), which is also the curve in (b). Since the brittleness of rock is related to its pre-peak elastoplastic deformation, the pre-peak deformation does not consider crack closure strain. Figure 5 Based on curve II shown in (b), the damage variable is calculated using the deformation modulus attenuation method. Therefore, B pre The calculation results are directly proportional to brittleness, i.e., B pre The larger the calculated value, the stronger the rock's brittleness. Post-peak brittleness evaluation index B. post Considering the maximum damage evolution rate and its corresponding strain ratio, it is clear that B post The larger the calculated value, the stronger the post-peak brittleness. Taking all factors into consideration, if the brittleness evaluation index B... DE The larger the calculated value, the stronger the brittleness of the rock. Specific Implementation

[0070] This embodiment provides a brittleness evaluation method based on the evolution characteristics of uniaxial compression damage in rocks, which is implemented through the following steps:

[0071] Step 1: Process the rock samples of different rock types collected from the engineering site into standard cylindrical specimens with a height of 100 mm and a diameter of 50 mm, and conduct uniaxial compression tests on each specimen to obtain the stress-strain curve of the specimen.

[0072] Step 2: Based on the test data of each sample, according to... Figure 5 As shown in (a), the crack closure strain of the rock sample can be obtained.

[0073] Step 3: Combining Figure 5 (b) Using the deformation modulus attenuation method Determine the rock damage evolution curve and determine the peak strain ε based on the peak stress point. p Damage variable value D corresponding to peak strain p .

[0074] Step 4: Fit the damage evolution curve obtained in Step 3 using Equation (1) to obtain the theoretical damage evolution equation under uniaxial compression of the rock sample; then calculate the first derivative of the obtained theoretical damage evolution equation, and determine the maximum damage evolution rate D based on the peak point of the first derivative. m ′ and its corresponding strain value ε m .

[0075] Step 5: Substitute the parameter values ​​obtained in steps 1-4 into equation (3) to calculate the rock sample brittleness evaluation index B. DE The value of the brittleness index is compared with existing rock brittleness evaluation indices to verify the rationality and reliability of the brittleness evaluation index proposed in this embodiment of the invention.

[0076] Granite and three different sandstone samples taken from the site were processed into standard cylindrical specimens with a height of 100 mm and a diameter of 50 mm. Indoor uniaxial compression tests were then conducted to obtain the uniaxial compressive stress-strain curves for each specimen (e.g., ...). Figure 6 (As shown).

[0077] Following steps 2-4 above, the theoretical damage evolution equations for each rock sample can be obtained as follows:

[0078] granite:

[0079] Sandstone 1:

[0080] Sandstone 2:

[0081] Sandstone 3:

[0082] Figure 7 The theoretical damage evolution curves and actual calculated damage results for each sample (based on the damage variable calculation formula) Comparing the calculated values, it can be seen that the rock theoretical damage model based on the Logistic growth model can better describe and predict the entire process of rock damage evolution. Further, by taking the first derivative of the theoretical damage evolution equation, its damage evolution rate curve, maximum damage evolution rate, and corresponding strain value can be obtained.

[0083] Based on the uniaxial compressive stress-strain curves and theoretical damage evolution curves of each rock sample, the parameter values ​​in the brittleness evaluation index can be obtained, as shown in Table 1. To verify the rationality and reliability of the brittleness evaluation index proposed in this invention, it is compared with the following brittleness evaluation index proposed by Xia Yingjie et al. in their paper (Xia Yingjie, Li Lianchong, Tang Chun'an et al. Evaluation method of rock mass brittleness characteristics based on post-peak stress drop rate and energy ratio [J]. Chinese Journal of Rock Mechanics and Engineering, 2016, 35(06): 1141-1154.):

[0084]

[0085] In the formula: σ p ε p Peak stress and peak strain, respectively, σ r ε r Residual stress and residual strain, respectively, B i This refers to the brittleness evaluation index proposed by Xia Yingjie.

[0086] Based on the calculated values ​​of the brittleness evaluation index, it can be found that the brittleness evaluation index B proposed in this invention... DE The brittleness evaluation index B proposed by Xia Yingjie i The evaluation results were consistent, with the brittleness relationship of different rock samples being: granite > sandstone 2 > sandstone 3 > sandstone 1. This indicates that the rock brittleness evaluation index proposed in this invention has a certain degree of rationality and reliability, can be applied to judge the degree of rock brittleness under normal conditions, and can obtain quantitative evaluation values. Moreover, the index has a simple form, few parameters, and strong applicability.

[0087] Table 1. Parameter values ​​of rock brittleness evaluation index

[0088]

[0089] Example 2

[0090] like Figure 8 As shown, another aspect of the present invention also includes a functional module architecture that is completely consistent with the aforementioned method flow. That is, the embodiments of the present invention also provide a brittleness evaluation device based on the uniaxial compression damage evolution characteristics of rocks, including:

[0091] The stress-strain curve acquisition module 801 is used to acquire the stress-strain curve of a rock specimen in a uniaxial compression test.

[0092] The rock damage evolution curve determination module 802 is used to determine the rock damage evolution curve based on the stress-strain curve and using the deformation modulus attenuation method.

[0093] The first parameter determination module 803 is used to determine the peak strain based on the peak stress point of the stress-strain curve, and to determine the damage variable value corresponding to the peak strain based on the rock damage evolution curve.

[0094] The fitting module 804 is used to fit the rock damage evolution curve to obtain the theoretical damage evolution equation of the rock sample.

[0095] The second parameter determination module 805 is used to calculate the first derivative of the theoretical damage evolution equation and determine the maximum damage evolution rate and its corresponding strain value based on the peak point of the first derivative.

[0096] The brittleness evaluation index calculation module 806 is used to calculate the brittleness evaluation index B of the rock sample using the following formula. DE :

[0097]

[0098] In the formula, ε cc The crack closure strain is determined by the intersection of the backward extension of the elastic stage of the stress-strain curve and the horizontal axis; ε p D represents the peak strain. p D represents the damage variable value corresponding to the peak strain. m ′ represents the maximum damage evolution rate; ε m B represents the strain value corresponding to the maximum damage evolution rate. DE B is an index for evaluating the brittleness of rock samples. pre B is an evaluation index for the pre-peak brittleness of rock samples. post It serves as an evaluation index for the post-peak brittleness of rock samples.

[0099] This device can be implemented using the brittleness evaluation method based on the evolution characteristics of uniaxial compression damage in rocks provided in Embodiment 1 above. The specific implementation method can be found in the description in Embodiment 1, and will not be repeated here.

[0100] The present invention also provides a memory that stores multiple instructions for implementing the brittleness evaluation method based on the uniaxial compression damage evolution characteristics of rocks as described in Embodiment 1.

[0101] The present invention also provides an electronic device, including a processor and a memory connected to the processor, the memory storing a plurality of instructions which can be loaded and executed by the processor to enable the processor to perform the brittleness evaluation method based on the uniaxial compression damage evolution characteristics of rocks as described in Embodiment 1.

[0102] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. A brittleness evaluation method based on the evolution characteristics of uniaxial compression damage in rocks, characterized in that, include: Obtain the stress-strain curves of uniaxial compression tests on rock specimens; Based on the stress-strain curve, the deformation modulus attenuation method is used to determine the rock damage evolution curve; The peak strain is determined based on the peak stress of the stress-strain curve, and the damage variable value corresponding to the peak strain is determined based on the rock damage evolution curve. The theoretical damage evolution equation of the rock sample was obtained by fitting the rock damage evolution curve with the Logistic growth model. The first derivative of the theoretical damage evolution equation is obtained, and the maximum damage evolution rate and its corresponding strain value are determined based on the peak point of the first derivative. The brittleness evaluation index of the rock sample is calculated using the following formula. : ； In the formula, ε cc The crack closure strain is determined by the intersection of the backward extension of the elastic stage of the stress-strain curve with the horizontal axis. ε p Peak strain; D p The value of the damage variable corresponding to the peak strain; D m ' The maximum damage evolution rate; ε m This represents the strain value corresponding to the maximum damage evolution rate. It serves as an indicator for evaluating the brittleness of rock samples; It serves as an evaluation index for the pre-peak brittleness of rock samples; It serves as an evaluation index for the post-peak brittleness of rock samples; The theoretical damage evolution equation for the rock sample is obtained by fitting the rock damage evolution curve using the following formula: ； In the formula, D For damage variables; a and r These are the fitting parameters; ε In response to the situation; The first derivative of the theoretical damage evolution equation is obtained using the following formula: 。 2. The brittleness evaluation method based on the uniaxial compression damage evolution characteristics of rocks as described in claim 1, characterized in that, The method of determining the rock damage evolution curve based on the stress-strain curve and using the deformation modulus attenuation method includes: Using formula Indicating damage variables ;in, Let be the slope of the line connecting any point on the stress-strain curve to the origin of the coordinate system. E It is the elastic modulus; The rock damage evolution curve is established using damage variables and their corresponding strains.

3. A brittleness evaluation device based on the evolution characteristics of uniaxial compression damage in rocks, characterized in that, include: The stress-strain curve acquisition module is used to acquire the stress-strain curves of uniaxial compression tests on rock specimens. The rock damage evolution curve determination module is used to determine the rock damage evolution curve based on the stress-strain curve and the deformation modulus attenuation method. The first parameter determination module is used to determine the peak strain based on the peak stress point of the stress-strain curve, and to determine the damage variable value corresponding to the peak strain based on the rock damage evolution curve. The fitting module is used to fit the rock damage evolution curve with the help of the Logistic growth model to obtain the theoretical damage evolution equation of the rock sample. The second parameter determination module is used to calculate the first derivative of the theoretical damage evolution equation and determine the maximum damage evolution rate and its corresponding strain value based on the peak point of the first derivative. The brittleness evaluation index calculation module is used to calculate the brittleness evaluation index of rock samples using the following formula. : ； In the formula, ε cc The crack closure strain is determined by the intersection of the backward extension of the elastic stage of the stress-strain curve with the horizontal axis. ε p Peak strain; D p The value of the damage variable corresponding to the peak strain; D m ' The maximum damage evolution rate; ε m This represents the strain value corresponding to the maximum damage evolution rate. It serves as an indicator for evaluating the brittleness of rock samples; It serves as an evaluation index for the pre-peak brittleness of rock samples; It serves as an evaluation index for the post-peak brittleness of rock samples; In the fitting module, the rock damage evolution curve is fitted to obtain the theoretical damage evolution equation of the rock sample, using the following formula: ； In the formula, D For damage variables; a and r These are the fitting parameters; ε In response to the situation; The fitting module is also used to calculate the first derivative of the theoretical damage evolution equation using the following formula: 。 4. The brittleness evaluation device based on the uniaxial compression damage evolution characteristics of rocks as described in claim 3, characterized in that, In the rock damage evolution curve determination module, the determination of the rock damage evolution curve based on the stress-strain curve and using the deformation modulus attenuation method includes: The damage variable is represented by the following formula. ;in, Let be the slope of the line connecting any point on the stress-strain curve to the origin of the coordinate system. E It is the elastic modulus; The rock damage evolution curve is established using damage variables and their corresponding strains.

5. A memory, characterized in that, The system stores multiple instructions for implementing the brittleness evaluation method based on the uniaxial compression damage evolution characteristics of rocks as described in any one of claims 1-2.

6. An electronic device, characterized in that, The system includes a processor and a memory connected to the processor. The memory stores multiple instructions that can be loaded and executed by the processor to enable the processor to perform the brittleness evaluation method based on the uniaxial compression damage evolution characteristics of rocks as described in any one of claims 1-2.

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