Nondestructive determination method and storage medium for rock damage degree in acidic water environment

Abstract

The present invention belongs to the field of rock detection technology, and specifically discloses a non-destructive determination method and storage medium for the degree of rock damage in an acidic water environment. The determination method is to collect a number of target rock samples, and then use an ultrasonic velocimeter to screen and label qualified rock samples; dehydrate and dry the qualified rock samples, and measure and record the dry density of the dehydrated and dried rock samples. r 0; Take at least 3 rock samples after dehydration and drying for compression test and calculate the average elastic modulus E 0 , Poisson's ratio average v 0 ; Soak the dehydrated and dried rock samples in an acid solution; after the soaking reaches the preset time, take out the rock samples and clean the surface acid solution, then dehydrate and dry the soaked rock samples and measure the dry density after erosion r t ; Combine the data before and after erosion to establish the rock damage rate or The present invention comprehensively reflects the degree of damage by measuring the changes in the physical and mechanical parameters of the rock sample, without destroying the rock sample, eliminating uncertain factors in the test process, and reducing the amount of data processing.

Description

Technical Field

[0001] The invention belongs to the technical field of rock detection, and specifically relates to a nondestructive determination method and storage medium for rock damage degree in an acidic water environment, which is nondestructive, has accurate results, high reliability and small data processing volume. Background Art

[0002] As one of the most active factors in the geological environment, water has a serious impact on the deformation and destruction of rocks. In particular, the acid rain caused by atmospheric pollution has made the coupling between water and rock one of the key factors affecting the safety and stability of rock engineering. Even relatively pure groundwater is a complex water chemical solution because it actually contains different ion components, pH and concentration. Rocks that have been below the water level for a long time will be eroded by groundwater. The erosion can change the mineral composition and internal structure of the rock at the microscopic level, expand its internal cracks, and then deteriorate its mechanical properties, leading to natural disasters. Therefore, how to evaluate the degradation characterization of rocks under the action of hydration erosion is crucial and remains a hot research topic in the industry.

[0003] At present, the damage detection of rocks under hydration erosion, especially in acidic water environment, can be evaluated by measuring its physical and mechanical properties, mass loss rate and changes in microstructure. For example, the physical and mechanical properties detection and evaluation is to detect the compressive strength, tensile strength and other indicators of the rock, so as to reflect the strength and stability of the rock, which is of great significance for evaluating the safety and applicability of the rock. The mass loss rate is to understand the degree of erosion of the rock by comparing the mass change of the rock before and after erosion, and then evaluate the impact of the hydration environment on the rock. The microstructural changes are analyzed by scanning electron microscopy and XRD diffraction tests to observe the microstructural changes of the rock in the hydration environment, such as changes in porosity and mineral composition, so as to directly reflect the degree of damage to the internal structure of the rock by the hydration environment through these microstructural changes, which is crucial for evaluating the durability and stability of the rock. Although the physical and mechanical properties testing and evaluation methods have high detection efficiency and are less affected by human factors, the conventional physical and mechanical properties parameters are difficult to comprehensively reflect the degree of damage due to the large differences in rock samples themselves and the large number of factors affecting rock damage, and may also cause rock sample damage; the mass loss rate detection efficiency is also high, but the damage to rock samples after erosion mostly occurs inside the rock, and it is difficult to fully characterize the degree of rock damage through the mass loss rate, resulting in large deviations in the evaluation results; although the microstructural change detection can comprehensively reflect the degree of rock damage, not only is the detection cost high, but the process is also cumbersome and may cause rock sample damage.

[0004] In the prior art, for the detection of the degree of rock damage under the action of hydration erosion, there has been a non-destructive testing method that uses the longitudinal wave velocity of the rock as a measurement standard and adopts relatively expensive means such as nuclear magnetic resonance and CT. These means, while measuring degradation, also use different degradation characterization methods, some of which are characterized by the damage area. This not only leads to a large amount of data processing, but also cumbersome operations, high detection costs, and is easily affected by multiple factors such as human factors, resulting in inaccurate test results. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a non-destructive determination method for the degree of rock damage in an acidic water environment which is non-destructive, has accurate results, high reliability and small data processing volume, and also provides a storage medium.

[0006] The non-destructive determination method of the present invention is implemented as follows: it includes the steps of rock sample preparation, pre-erosion pretreatment, pre-erosion physical test, erosion treatment, post-erosion pretreatment, and rock mass damage rate calculation, and the specific contents of each step are as follows;

[0007] A. Rock sample preparation: Collect several cylindrical target rock samples, then use ultrasonic velocimeter to screen qualified rock samples, and then label the qualified rock samples;

[0008] B. Pretreatment before erosion: Dehydrate and dry the previously labeled rock samples, and then measure and record the dry density of each dehydrated and dried rock sample. r 0;

[0009] C. Physical test before erosion: Take the three rock samples after dehydration and drying mentioned above and conduct compression test to obtain the elastic modulus of each rock sample. E , Poisson's ratio v , record the above data and calculate the corresponding average value E 0 , v 0 ;

[0010] D. Erosion treatment: soak the dehydrated and dried rock samples in a pre-prepared acid solution for a preset erosion time;

[0011] E. Pretreatment after erosion: After the soaked rock sample reaches the preset time, take it out and clean the surface acid solution, then treat the soaked rock sample according to step B to obtain the dry density after erosion. r t ;

[0012] F. Calculation of rock mass damage rate: Combine the data before and after erosion to establish a rock mass damage rate model or And calculate:

[0013] (1),

[0014] Where: a is the damage parameter before erosion, b is the damage parameter after erosion;

[0015] in: (2),

[0016] (3),

[0017] (4),

[0018] (5),

[0019] (6),

[0020] (7),

[0021] (8),

[0022] Where: V 测0 is the measured wave velocity of the rock sample before erosion, V 理论0 is the theoretical wave velocity of the rock sample before erosion, V 测t is the measured wave velocity of the rock sample after erosion, V 理论t is the theoretical wave velocity of the rock sample after erosion, E t is the average elastic modulus of the rock sample after erosion, v t is the average Poisson's ratio of the rock sample after erosion, is the medium wave velocity inside the rock sample before erosion, is the medium wave velocity inside the rock sample after erosion.

[0023] Furthermore, in step A, the sampling depth of the target rock sample is 0.5-2m, the sampling drill diameter is 40-60mm and the height is 80-120mm; the ultrasonic velocimeter is used to screen qualified rock samples, and the ultrasonic velocimeter is used to measure the longitudinal wave velocity of the rock sample, and the rock samples with a wave velocity of 4600-5000m / s, small wave velocity difference of individual rock samples and no obvious cracks on the surface are selected as qualified rock samples.

[0024] Furthermore, in step B, the labeled rock samples are placed in a vacuum drying oven, and then dried at a constant temperature of 100-110°C for 36-60 hours, and then air-cooled to room temperature, and the dry mass of each rock sample is measured and recorded, and then the volume of each rock sample is determined by the water displacement method, and finally the dry density of each rock sample is calculated one by one. r 0 .

[0025] Furthermore, in the step B, each rock sample whose volume is measured by the water displacement method is placed in a vacuum drying oven again, and then dried at a constant temperature of 105-110° C. for 24 hours, and then air-cooled to room temperature for use.

[0026] Furthermore, in the step E, the surface cleaned rock samples are screened again using an ultrasonic velocimeter, and the qualified soaked rock samples are processed according to the step B to obtain the dry density after erosion. r t .

[0027] Furthermore, in the step D, the dehydrated and dried rock samples are placed in a sealed container, the sealed container is vacuumed to 0.05-0.20 MPa and the pressure is maintained for 5-10 hours, then the air extraction valve of the sealed container is closed and the water inlet valve is opened, so that the pre-prepared acid solution is introduced into the sealed container and covers the rock samples, and the rock samples are allowed to stand and soak in the pre-prepared acid solution for acid corrosion for a preset time.

[0028] Furthermore, the acid solution in the sealed container covers the top surface of the rock sample by more than 10 cm, and the rock sample is corroded by the acid solution for 20 to 40 days.

[0029] Furthermore, in the step F, since the medium inside the rock sample before erosion is air, ; The medium inside the rock sample after erosion is an acidic solution, so .

[0030] Furthermore, the present invention also includes a damage rate calculation step, wherein the damage rate calculation is to calculate the damage amount Δ of the rock mass after erosion:

[0031] (9),

[0032] Where: s is the initial compressive strength of the rock sample;

[0033] Wherein, the initial compressive strength s It is the average value of the data obtained from the compressive strength test of at least 3 rock samples taken in step C after dehydration and drying.

[0034] The storage medium of the present invention is implemented as follows: a computer program is stored on the storage medium, and the computer program can be executed by one or more processors to implement the aforementioned method for non-destructive determination of the degree of rock damage in an acidic water environment.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The non-destructive determination method of the present invention first uses an ultrasonic velocimeter to eliminate unqualified rock samples with large wave velocity differences (i.e., large internal defects) and obvious cracks on the surface, thereby avoiding the influence of the quality problems of the rock samples themselves on the subsequent determination results; then the dry density ρ0 of the rock samples before erosion and the elastic modulus of some rock samples are measured. E , Poisson's ratio v , and the dry density of the eroded rock sample r t , and pioneered the establishment of rock damage rate based on the above physical and mechanical parameters or The model can comprehensively and quantitatively reflect the degree of damage to the rock after erosion, which is closer to the actual damage of the rock mass. Moreover, the measurement cost is much lower than non-destructive testing methods such as nuclear magnetic resonance and CT.

[0037] 2. The non-destructive determination method of the present invention, except for a small number of rock samples that need to be measured for elastic modulus and Poisson's ratio, will be damaged. Other rock samples are only subjected to preliminary ultrasonic velocimeter velocity measurement and dry density before and after erosion. r 0. r t Therefore, no damage will be caused during the measurement process, and the rock samples after the measurement can still be used for other tests.

[0038] 3. The nondestructive measurement method of the present invention can eliminate the shortcomings of the rock sample itself due to large defects through early ultrasonic elimination, and the quantitative measurement of the physical and mechanical parameters of the rock sample before and after erosion can reduce or even eliminate human interference, thereby basically eliminating uncertain factors in the measurement process and improving the accuracy and reliability of the measurement results; and because the measured physical and mechanical parameters are simple and the amount of data is small, it can not only reduce the measurement workload and improve the measurement efficiency, but also reduce the amount of data processing in the later stage.

[0039] In summary, the present invention has the characteristics of being lossless, having accurate results, high reliability and small data processing volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a flow chart of the nondestructive measurement method of the present invention,

[0041] In the figure: A-rock sample preparation, B-pretreatment before erosion, C-physical test before erosion, D-erosion treatment, E-pretreatment after erosion, F-rock damage rate calculation, G-damage rate calculation. DETAILED DESCRIPTION

[0042] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited in any way. Any changes or improvements made based on the teachings of the present invention belong to the protection scope of the present invention.

[0043] like Figure 1As shown, the non-destructive determination method of the present invention includes the steps of rock sample preparation, pre-erosion pretreatment, pre-erosion physical test, erosion treatment, post-erosion pretreatment, and rock mass damage rate calculation, and the specific contents of each step are as follows;

[0044] A. Rock sample preparation: Collect several cylindrical target rock samples, then use ultrasonic velocimeter to screen qualified rock samples, and then label the qualified rock samples;

[0045] B. Pretreatment before erosion: Dehydrate and dry the previously labeled rock samples, and then measure and record the dry density of each dehydrated and dried rock sample. r 0;

[0046] C. Physical test before erosion: Take the three rock samples after dehydration and drying mentioned above and conduct compression test to obtain the elastic modulus of each rock sample. E , Poisson's ratio v , record the above data and calculate the corresponding average value E 0 , v 0 ;

[0047] D. Erosion treatment: soak the dehydrated and dried rock samples in a pre-prepared acid solution for a preset erosion time;

[0048] E. Pretreatment after erosion: After the soaked rock sample reaches the preset time, take it out and clean the surface acid solution, then treat the soaked rock sample according to step B to obtain the dry density after erosion. r t ;

[0049] F. Calculation of rock mass damage rate: Combine the data before and after erosion to establish the rock mass damage rate or Model and calculate:

[0050] (1),

[0051] Where: a is the damage parameter before erosion, b is the damage parameter after erosion;

[0052] in: (2),

[0053] (3),

[0054] (4),

[0055] (5),

[0056] (6),

[0057] (7),

[0058] (8),

[0059] Where: V 测0 is the measured wave velocity of the rock sample before erosion, V 理论0 is the theoretical wave velocity of the rock sample before erosion, V 测t is the measured wave velocity of the rock sample after erosion, V 理论t is the theoretical wave velocity of the rock sample after erosion, E t is the average elastic modulus of the rock sample after erosion, v t is the average Poisson's ratio of the rock sample after erosion, is the medium wave velocity inside the rock sample before erosion, is the medium wave velocity inside the rock sample after erosion.

[0060] In step A, the sampling depth of the target rock sample is 0.5-2m, the sampling drill diameter is 40-60mm and the height is 80-120mm; the ultrasonic velocimeter is used to screen qualified rock samples, and the ultrasonic velocimeter is used to measure the longitudinal wave velocity of the rock sample, and the rock samples with a wave velocity of 4600-5000m / s, small wave velocity difference of individual rock samples and no obvious cracks on the surface are selected as qualified rock samples.

[0061] In step B, the labeled rock samples are placed in a vacuum drying oven, then dried at a constant temperature of 100-110°C for 36-60 hours, then air-cooled to room temperature, the dry mass of each rock sample is measured and recorded, and the volume of each rock sample is then determined by the water displacement method, and finally the dry density of each rock sample is calculated one by one. r 0 .

[0062] In the step B, each rock sample whose volume is measured by the water displacement method is placed in a vacuum drying oven again, and then dried at a constant temperature of 105-110° C. for 24 hours, and then air-cooled to room temperature for use.

[0063] In the step E, the surface cleaned rock samples are screened again using an ultrasonic velocimeter, and the qualified soaked rock samples are processed according to the step B to obtain the dry density after erosion. r t .

[0064] In the step D, the dehydrated and dried rock samples are placed in a sealed container, the sealed container is vacuumed to 0.05-0.20 MPa and the pressure is maintained for 5-10 hours, then the air extraction valve of the sealed container is closed and the water inlet valve is opened, so that the pre-prepared acid solution is introduced into the sealed container and covers the rock samples, and the rock samples are allowed to stand and soak in the pre-prepared acid solution for a preset time for acid corrosion.

[0065] The acid solution in the sealed container covers the top surface of the rock sample by more than 10 cm, and the rock sample is corroded by the acid solution for 20 to 40 days.

[0066] In the F step, since the medium inside the rock sample before erosion is air, ; The medium inside the rock sample after erosion is an acidic solution, so .

[0067] The present invention also includes a damage rate calculation step, wherein the damage rate calculation is to calculate the damage amount Δ of the rock mass after erosion:

[0068] (9),

[0069] Where: s is the initial compressive strength of the rock sample;

[0070] Wherein, the initial compressive strength s It is the average value of the data obtained from the compressive strength test of at least 3 rock samples taken in step C after dehydration and drying.

[0071] The acidic solution is a hydrochloric acid, sulfuric acid and / or nitric acid solution with a pH value of 3-5.

[0072] The storage medium of the present invention stores a computer program thereon, and the computer program can be executed by one or more processors to implement the aforementioned method for non-destructive determination of the degree of rock damage in an acidic water environment.

[0073] Example

[0074] S100: According to the requirements of sampling depth of 0.5-2m, sampling drill diameter of 40-60mm and height of 80-120mm, 10 cylindrical andesite target rock samples were collected from Ali area of ​​Tibet; then the longitudinal wave velocity of the rock samples was measured by ultrasonic velocimeter, and the rock samples with wave velocity of 4600-5000m / s and no obvious cracks on the surface were selected as qualified rock samples, and then the qualified rock samples were numbered one by one.

[0075] S200: Place the 10 rock samples marked above in a vacuum drying oven, and then dry them at a constant temperature of 105°C for 48 hours. Then open the vacuum drying oven to allow the rock samples to cool to room temperature with the furnace. Measure and record the dry mass of each rock sample, then use the water displacement method to determine the volume of each rock sample, and finally calculate the dry density of each rock sample one by one. r 0; The rock samples whose volumes were determined by the water displacement method were placed in a vacuum drying oven again, and then dried at a constant temperature of 105-110°C for 24 h, and then air-cooled to room temperature for use.

[0076] S300: Extract the three rock samples after dehydration and drying mentioned above and conduct compression test to obtain the elastic modulus of each rock sample. E , Poisson's ratio v , record the above data and calculate the corresponding average value E 0 , v 0 .

[0077] S400: Place the five rock samples that have been dehydrated and dried above into a glass container (such as a beaker), then place the glass container containing the rock samples into a vacuum pumping and saturation device, then evacuate the vacuum pumping and saturation device to a vacuum of 0.05-0.20 MPa and maintain the pressure for 8 hours, then close the vacuum pumping and saturation device's vacuum valve and open the water inlet valve, so that a pre-prepared nitric acid solution with a pH value of 3 is introduced into the glass container and covers the top surface of the rock sample by more than 10 cm, then open the vacuum pumping and saturation device's door and cover the glass container with a glass cover to prevent CO2 in the air from affecting the test results, and allow the rock sample to be immersed in the pre-prepared nitric acid solution for acid corrosion for 30 days.

[0078] S500: After soaking the rock sample for 30 days, take it out and clean the surface nitric acid solution. Then use ultrasonic velocimeter to screen the soaked rock sample again. The qualified soaked rock sample is processed according to S200 to obtain the dry density after erosion. r t .

[0079] S600: Combine data before and after erosion to establish rock mass damage rate or Model:

[0080] (1),

[0081] Where: a is the damage parameter before erosion, b is the damage parameter after erosion;

[0082] in: (2),

[0083] (3),

[0084] (4),

[0085] (5),

[0086] (6),

[0087] (7),

[0088] (8),

[0089] Where: V 测0 is the measured wave velocity of the rock sample before erosion, V 理论0 is the theoretical wave velocity of the rock sample before erosion, V 测t is the measured wave velocity of the rock sample after erosion, V 理论t is the theoretical wave velocity of the rock sample after erosion, E t is the average elastic modulus of the rock sample after erosion, v t is the average Poisson's ratio of the rock sample after erosion, is the medium wave velocity inside the rock sample before erosion, is the medium wave velocity inside the rock sample after erosion.

[0090] S700: Calculate the damage amount of the rock mass after erosion Δ:

[0091] (9),

[0092] Where: s is the initial compressive strength of the rock sample;

[0093] Wherein, the initial compressive strength s It is the average value of the data obtained from the compressive strength test of the three rock samples taken after dehydration and drying in step C.

[0094] The basic parameters of the embodiment are shown in Table 1, and the degradation parameters are shown in Table 2.

[0095] Table 1: Basic parameters

[0096]

[0097] Table 2: Degradation parameters

[0098]

[0099] It can be concluded from Tables 1 and 2 that the damage rate of andesite after hydration erosion is less than 0.11, and the theoretical compressive strength after damage is generally smaller than the actual compressive strength, with an error of ±0.1~±3.8%. The numerical error is ±0.08~1.78Mpa, which is relatively small, verifying the feasibility of this method.

[0100] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A non-destructive method for determining the degree of rock damage in an acidic water environment, characterized in that: It includes rock sample preparation, pre-erosion pretreatment, pre-erosion physical test, erosion treatment, post-erosion pretreatment, and rock mass damage rate calculation steps. The specific contents of each step are as follows; A. Rock sample preparation: Collect several cylindrical target rock samples, then use ultrasonic velocimeter to screen qualified rock samples, and then label the qualified rock samples; B. Pretreatment before erosion: Dehydrate and dry the previously labeled rock samples, and then measure and record the dry density of each dehydrated and dried rock sample. ρ 0; C. Physical test before erosion: Take at least three rock samples after dehydration and drying as mentioned above and conduct compression test to obtain the elastic modulus of each rock sample. E , Poisson's ratio v , record the above data and calculate the corresponding average value E 0 , v 0 ; D. Erosion treatment: soak the dehydrated and dried rock samples in a pre-prepared acid solution for a preset erosion time; E. Pretreatment after erosion: After the soaked rock sample reaches the preset time, take it out and clean the surface acid solution, then treat the soaked rock sample according to step B to obtain the dry density after erosion. ρ t ; F. Calculation of rock mass damage rate: Combine the data before and after erosion to establish the rock mass damage rate η Model and calculate: （1）， Where: a is the damage parameter before erosion, b is the damage parameter after erosion; in: (2), （3）， （4）， （5）， （6）， （7）， （8）， Where: V 测0 is the measured wave velocity of the rock sample before erosion, V 理论0 is the theoretical wave velocity of the rock sample before erosion, V 测t is the measured wave velocity of the rock sample after erosion, V 理论t is the theoretical wave velocity of the rock sample after erosion, E t is the average elastic modulus of the rock sample after erosion, v t is the average Poisson's ratio of the rock sample after erosion, is the medium wave velocity inside the rock sample before erosion, is the medium wave velocity inside the rock sample after erosion; In step A, the sampling depth of the target rock sample is 0.5-2m, the sampling drill diameter is 40-60mm and the height is 80-120mm; the ultrasonic velocimeter is used to screen qualified rock samples, and the ultrasonic velocimeter is used to measure the longitudinal wave velocity of the rock sample, and the rock samples with a wave velocity of 4600-5000m / s and no obvious cracks on the surface are selected as qualified rock samples.

2. The non-destructive determination method of rock damage degree in acidic water environment according to claim 1 is characterized in that: In step B, the labeled rock samples are placed in a vacuum drying oven, then dried at a constant temperature of 100-110°C for 36-60 hours, then air-cooled to room temperature, the dry mass of each rock sample is measured and recorded, and the volume of each rock sample is then determined by the water displacement method, and finally the dry density of each rock sample is calculated one by one. ρ 0 .

3. The non-destructive determination method of rock damage degree in acidic water environment according to claim 2 is characterized in that: In the step B, each rock sample whose volume is measured by the water displacement method is placed in a vacuum drying oven again, and then dried at a constant temperature of 105-110° C. for 24 hours, and then air-cooled to room temperature for use.

4. The non-destructive determination method of rock damage degree in acidic water environment according to claim 1 is characterized in that: In the step E, the surface cleaned rock samples are screened again using an ultrasonic velocimeter, and the qualified soaked rock samples are processed according to the step B to obtain the dry density after erosion. ρ t .

5. The non-destructive determination method of rock damage degree in acidic water environment according to claim 1 is characterized in that: In the step D, the dehydrated and dried rock samples are placed in a sealed container, the sealed container is vacuumed to 0.05-0.20 MPa and the pressure is maintained for 5-10 hours, then the air extraction valve of the sealed container is closed and the water inlet valve is opened, so that the pre-prepared acid solution is introduced into the sealed container and covers the rock samples, and the rock samples are allowed to stand and soak in the pre-prepared acid solution for a preset time for acid corrosion.

6. The non-destructive determination method of rock damage degree in acidic water environment according to claim 5 is characterized in that: The acid solution in the sealed container covers the top surface of the rock sample by more than 10 cm, and the rock sample is corroded by the acid solution for 20 to 40 days.

7. The non-destructive determination method of rock damage degree in an acidic water environment according to any one of claims 1 to 6, characterized in that: In the F step, since the medium inside the rock sample before erosion is air, ; The medium inside the rock sample after erosion is an acidic solution, so .

8. The non-destructive determination method of rock damage degree in acidic water environment according to claim 7 is characterized in that: The damage rate calculation step is also included, wherein the damage rate calculation is to calculate the damage amount Δ of the rock mass after erosion: （9）， Where: σ is the initial compressive strength of the rock sample; Wherein, the initial compressive strength σ It is the average value of the data obtained from the compressive strength test of at least 3 rock samples taken in step C after dehydration and drying.

9. A storage medium having a computer program stored thereon, characterized in that: The computer program can be executed by one or more processors to implement the non-destructive determination method of the degree of rock damage in an acidic water environment as described in any one of claims 1 to 8.

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