Rock mass damage evaluation method based on drilling vibration waveform

Abstract

The invention relates to the technical field of tunnel engineering, and discloses a rock mass damage evaluation method based on drilling vibration waveform, which comprises the following steps: step S1, preparation of samples with different lithology: preparing samples matched with field lithology according to engineering geological conditions of a construction field, each group comprising at least six samples; step S2, indoor uniaxial test: selecting three samples in each group prepared in the step S1, performing uniaxial compression test on the samples, recording the elastic modulus of each group of samples, and obtaining the average value E of the elastic modulus of the samples with different lithology. And S3, indoor drilling test: carrying out indoor drilling test on the other three samples of each group of test pieces, and arranging a vibration sensor on a drilling device. According to the method, the measurement model of the elastic modulus and the vibration parameters is constructed, and the drilling vibration data are monitored and output in real time when the tunnel face is drilled, so that the rock damage can be evaluated relatively accurately in real time, and an effective damage evaluation method is established.

Description

Technical Field

[0001] The invention relates to the technical field of rock damage evaluation, and in particular to a rock damage evaluation method based on drilling vibration waveform. Background Art

[0002] Commonly used methods in tunnel construction include drilling and blasting, New Austrian Tunneling Method, shield tunneling, etc. Commonly used technical methods include step blasting. The shock waves generated in tunnel blasting will disturb and affect the surrounding rock and surrounding buildings. Surrounding rock damage evaluation is the key and difficult problem of tunnel construction. In order to reduce the damage of blasting to the surrounding rock and the impact of surrounding buildings, it is a challenging task to establish a corresponding damage evaluation method. For example, the Shuncheng Tunnel under construction is only 24m away from the nearest residential area. During the construction process, it has a great impact on residents and seriously affects the progress of construction. However, the current evaluation methods for surrounding rock damage are mostly based on the analysis of drilling monitoring data. The evaluation process is relatively slow and it is difficult to quickly evaluate the damage of the surrounding rock. Therefore, it is of great significance to develop a fast and effective damage evaluation method. Summary of the invention

[0003] In order to solve the technical problems raised in the background technology, the present invention provides a rock damage evaluation method based on drilling vibration waveform.

[0004] The present invention is implemented by the following technical solution: A rock damage evaluation method based on drilling vibration waveform comprises the following steps:

[0005] Step S1, preparation of samples of different lithology: according to the engineering geology of the construction site, prepare samples that match the lithology of the site, with at least 6 samples in each group.

[0006] Step S2, indoor uniaxial test: select 3 samples from each of the multiple groups of samples prepared in S1, perform uniaxial tests on them, record the elastic modulus of each group of samples, and obtain the mechanical parameters of the average value E of the elastic modulus of each sample.

[0007] Step S3, indoor drilling test: another rock sample of each group of test pieces is subjected to indoor drilling test, a vibration sensor is arranged on the drill bit, and the vibration parameters of each group of rock samples are recorded. The maximum value of each group of data is finally selected for subsequent analysis.

[0008] Step S4, test data and processing: the mechanical parameters obtained in step S2 and step S3 are matched with the vibration signal, the elastic modulus of each group of rock samples and its corresponding vibration parameter are recorded, a relationship diagram between the elastic modulus and each vibration parameter is drawn in the XY coordinate system, and the linear relationship between the elastic modulus and the vibration parameter is determined, thereby constructing a measurement model of the elastic modulus and the vibration parameter.

[0009] Step S5, on-site drilling data monitoring: a real-time drilling monitoring system is implemented at the tunnel face, and the drilling monitoring data can be output in real time.

[0010] Step S6, damage assessment: The elastic modulus is calculated in real time by combining the vibration data obtained through the on-site drilling test with the measurement model obtained in step S4, and the rock damage is calculated using the calculation formula D=1-E0 / E, where E0 is the elastic modulus measured in real time and E is the original elastic modulus.

[0011] As a further improvement of the above scheme, the vibration parameters include vibration velocity, vibration frequency, and vibration acceleration. Considering that vibration velocity, vibration frequency, and vibration acceleration will all affect the elastic modulus, the accuracy of the established measurement function will be higher through multi-parameter factors.

[0012] As a further improvement of the above scheme, in step 1, a sample is drilled from the rock block using a drilling sampler. Multiple groups of samples are obtained to obtain multiple groups of data, making the experimental results more accurate.

[0013] As a further improvement of the above scheme, the specimen is mounted on a testing machine and ensured to be placed vertically to avoid generating additional stress during loading; pressure is applied to the specimen at a constant loading rate until the specimen is damaged; during loading, stress and strain data are recorded in real time; a stress-strain curve is drawn based on the recorded stress and strain data; within the elastic range of the stress-strain curve, an interval with a better linear relationship is selected; the slope of the curve within the interval is taken as the elastic modulus of the specimen, and the elastic modulus E is calculated using the formula: E=σ / ε, where σ is stress and ε is strain.

[0014] As a further improvement of the above scheme, the operation in step 3 is as follows

[0015] Lift the sample through the bottom axial pressure loading device, adjust and fix the position of the sample; turn on the press, apply a predetermined axial pressure to the sample, keep the axial pressure stable, and ensure that the pressure fluctuation is within the allowable range during the test; after ensuring that there is no obstruction in front of the drilling rig, turn on the horizontal propulsion switch of the drilling rig, adjust the parameters such as the drilling rig speed, propulsion cylinder pressure and torque sensor, and conduct preliminary drilling and rock breaking tests; after the drilling process is stable, conduct formal drilling according to the experimental plan, and observe and record various parameters during the drilling process, such as torque, propulsion force, and acoustic emission signals in real time; turn on the data collection software, record and save various data during the drilling process in real time, organize and analyze the collected data, and calculate the elastic modulus, strength and other mechanical parameters of the sample.

[0016] As a further improvement of the above scheme, in step S3, a metric model between the elastic modulus and the vibration parameter is obtained by establishing a random forest model;

[0017] The steps to build the random forest model are as follows;

[0018] Step A, statistically analyzing the experimental data of the samples obtained in step S2 and step S3, and constructing a data set after data expansion;

[0019] Step B, preprocessing the input data;

[0020] Step C, dividing the data set into a training set and a test set; using the training set data to train the random forest model to obtain a random forest model based on vibration parameters;

[0021] Step D: testing the random forest model based on vibration parameters through a test set.

[0022] As a further improvement of the above solution, in step A, an interpolation method may be used to expand the experimental data of the samples obtained in steps S2 and S3.

[0023] As a further improvement of the above scheme, step B specifically includes data cleaning and feature scaling. Since different features have different dimensions and ranges, they need to be normalized or standardized to improve the efficiency and accuracy of model training.

[0024] As a further improvement of the above scheme, the data is standardized and normalized using the Min-Max standardization method or the range standardization method.

[0025] As a further improvement of the above scheme, in step B, the index weights of each vibration parameter are calculated respectively using the hierarchical analysis method and the coefficient of variation method, and finally the input data is the vibration parameter, and the output data is the elastic modulus regression model, E0=a·v+bv'+cf, wherein v is the vibration velocity, v' is the vibration acceleration, f is the vibration frequency, and a, b, and c are the influence coefficients of each corresponding vibration parameter on the elastic modulus after calculation.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] Compared with the prior art, the present invention obtains mechanical parameters corresponding to vibration signals, records the elastic modulus of each group of rock samples and the corresponding vibration parameters, draws a relationship diagram between the elastic modulus and each vibration parameter in an XY coordinate system, and constructs a measurement model of the elastic modulus and the vibration parameters by calculating the linear relationship between the elastic modulus and the vibration parameters. In this way, real-time monitoring is performed when drilling at the tunnel face, and drilling monitoring data can be output in real time, so that rock damage can be evaluated in real time and relatively accurately, thereby establishing an effective damage evaluation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1This is a flowchart of the damage assessment method proposed in the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0030] Example:

[0031] Reference Figure 1 ,This scheme proposes a rock damage evaluation method based on drilling vibration waveform, including the following steps:

[0032] Step S1, preparation of samples of different lithology: according to the engineering geology of the construction site, prepare samples that match the lithology of the site, with each group of samples having at least 6, and prepare 6 groups;

[0033] Step S2, indoor uniaxial test: select 3 samples from each of the multiple groups of samples prepared in S1, perform uniaxial tests on them, record the elastic modulus of each group of samples, and obtain the average value E of the elastic modulus of each sample and other mechanical parameters;

[0034] Step S3, indoor drilling test: another rock sample of the 6 groups of test pieces is subjected to indoor drilling test, a vibration sensor is arranged on the drill bit, the vibration parameters of each group of rock samples are recorded, and the maximum value of each group of data is finally selected for subsequent analysis;

[0035] Step S4, test data and processing: the mechanical parameters obtained in step S2 and step S3 are matched with the vibration signal, the elastic modulus of each group of rock samples and the corresponding vibration parameter are recorded, a relationship diagram between the elastic modulus and each vibration parameter is drawn in the XY coordinate system, and the linear relationship between the elastic modulus and the vibration parameter is determined, thereby constructing a measurement model of the elastic modulus and the vibration parameter;

[0036] Step S5, on-site drilling data monitoring: a real-time drilling monitoring system is implemented at the tunnel face, and the drilling monitoring data can be output in real time;

[0037] Step S6, damage assessment: The elastic modulus is calculated in real time by combining the vibration data obtained through the on-site drilling test with the measurement model obtained in step S4, and the rock damage is calculated using the calculation formula D=1-E0 / E, where E0 is the elastic modulus measured in real time and E is the original elastic modulus.

[0038] Vibration parameters include vibration velocity, vibration frequency, and vibration acceleration.

[0039] During the specific work, in step 1, a sample is drilled from a rock block using a drilling sampler.

[0040] The operation of step 2 is as follows:

[0041] The specimen is mounted on the testing machine and placed vertically to avoid generating additional stress during loading. The specimen is subjected to pressure at a constant loading rate (stress rate) until the specimen is damaged. During loading, stress and strain data are recorded in real time. These data will be used to calculate the elastic modulus later. Based on the recorded stress and strain data, a stress-strain curve is drawn. Within the elastic range of the stress-strain curve, a region with a good linear relationship is found. The slope of this region is the elastic modulus of the specimen, and the elastic modulus E is calculated using the formula: E = σ / ε, where σ is stress and ε is strain.

[0042] The operation in step 3 is as follows: lift the sample through the bottom axial pressure loading device, adjust and fix the position of the sample; turn on the press, apply a predetermined axial pressure to the sample, keep the axial pressure stable, and ensure that the pressure fluctuation is within the allowable range during the test; after ensuring that there is no debris blocking the front of the drilling rig, turn on the horizontal propulsion switch of the drilling rig, adjust the parameters such as the drilling rig speed, propulsion cylinder pressure and torque sensor, and conduct a preliminary drilling and rock breaking test; after the drilling process is stable, conduct formal drilling according to the experimental plan, and observe and record various parameters in the drilling process in real time, such as torque, propulsion force, acoustic emission signals, etc.; turn on the data collection software, record and save various data in the drilling process in real time, organize and analyze the collected data, and calculate the elastic modulus, strength and other mechanical parameters of the sample.

[0043] As an optional implementation of the present invention, in step S3, a metric model between the elastic modulus and the vibration parameter is obtained by establishing a random forest model; the steps of constructing the random forest model are as follows;

[0044] Step A, statistically analyzing the experimental data of the samples obtained in step S2 and step S3, and constructing a data set after data expansion;

[0045] Step B, preprocessing the input data;

[0046] Step C, dividing the data set into a training set and a test set; using the training set data to train the random forest model to obtain a random forest model based on vibration parameters;

[0047] Step D: testing the random forest model based on vibration parameters through a test set.

[0048] It should be noted that, in step A, the experimental data of the samples obtained in steps S2 and S3 may be expanded by using an interpolation method.

[0049] Step B specifically includes data cleaning and feature scaling. Since different features (such as vibration frequency and vibration acceleration) may have different dimensions and ranges, they need to be normalized or standardized to improve the efficiency and accuracy of model training.

[0050] In this scheme, the Min-Max standardization method or the range standardization method is used to standardize and normalize the data.

[0051] Furthermore, in step B, the index weights of each vibration parameter are calculated using the hierarchical analysis method and the coefficient of variation method, and finally the input data is the vibration parameter, and the output data is the elastic modulus regression model. E0 =a·v+bv'+cf, where v is the vibration velocity, v' is the vibration acceleration, f is the vibration frequency, and a, b, and c are the influence coefficients of the calculated corresponding vibration parameters on the elastic modulus.

[0052] The evaluation method proposed in the present invention records the elastic modulus of each group of rock samples and the corresponding vibration parameters by corresponding the obtained mechanical parameters to the vibration signals, draws a relationship diagram between the elastic modulus and each vibration parameter in an XY coordinate system, and constructs a measurement model of the elastic modulus and the vibration parameters by calculating the linear relationship between the elastic modulus and the vibration parameters. In this way, real-time monitoring is performed when drilling at the tunnel face, and drilling monitoring data can be output in real time, so that rock damage can be evaluated in real time and relatively accurately, thereby establishing an effective damage evaluation method.

[0053] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A rock damage assessment method based on drilling vibration waveform, characterized in that: The following steps are involved: Step S1, preparation of samples of different lithology: according to the engineering geology of the construction site, prepare samples that match the lithology of the site, with each group of samples having at least 6; Step S2, indoor uniaxial test: select 3 samples from each of the multiple groups of samples prepared in S1, perform uniaxial tests on them, record the elastic modulus of each group of samples, and obtain the average value E of the elastic modulus of each sample and other mechanical parameters; Step S3, indoor drilling test: perform indoor drilling test on other rock samples of each group of test pieces, arrange vibration sensors on the drill bit, record vibration parameters of each group of rock samples, and finally select the maximum value of each group of data for subsequent analysis; Step S4, test data and processing: the mechanical parameters obtained in step S2 and step S3 are matched with the vibration signal, the elastic modulus of each group of rock samples and the corresponding vibration parameter are recorded, a relationship diagram between the elastic modulus and each vibration parameter is drawn in the XY coordinate system, and the regression relationship between the elastic modulus and the vibration parameter is determined, so as to construct a measurement model of the elastic modulus and the vibration parameter; Step S5, on-site drilling data monitoring: constructing a real-time drilling monitoring system at the tunnel face and outputting drilling vibration data in real time; Step S6, damage assessment: The elastic modulus is calculated in real time by combining the vibration data obtained through the on-site drilling test with the measurement model obtained in step S4, and the rock damage is calculated using the calculation formula D=1-E / E0, where E is the elastic modulus measured in real time and E0 is the original elastic modulus.

2. A rock damage assessment method based on drilling vibration waveform as claimed in claim 1, characterized in that: Vibration parameters include vibration velocity, vibration frequency, and vibration acceleration.

3. A rock damage assessment method based on drilling vibration waveform as claimed in claim 1, characterized in that: In the step 1, a sample is drilled from a rock block using a drilling sampler.

4. A rock damage assessment method based on drilling vibration waveform as claimed in claim 1, characterized in that: The operation of step 2 is as follows: Install the specimen on the testing machine and ensure that it is placed vertically to avoid additional stress during loading; Apply pressure to the specimen at a constant loading rate until the specimen fails; During the loading process, stress and strain data are recorded in real time; Based on the recorded stress and strain data, draw a stress-strain curve; In the elastic range of the stress-strain curve, select the interval with a better linear relationship; The slope of the curve in this interval is taken as the elastic modulus of the sample, and the calculation formula of the elastic modulus E is: E=σ / ε, where σ is stress and ε is strain.

5. The rock damage assessment method based on drilling vibration waveform according to claim 1, characterized in that: The operation in step 3 is as follows Lift the sample through the bottom axial pressure loading device, adjust and fix the position of the sample; Turn on the press, apply a predetermined axial pressure to the sample, keep the axial pressure stable, and ensure that the pressure fluctuation during the test is within the allowable range; After ensuring that there are no obstacles in front of the drilling rig, turn on the horizontal propulsion switch of the drilling rig, adjust the parameters such as the drilling rig speed, propulsion cylinder pressure and torque sensor, and conduct preliminary drilling and rock breaking tests; after the drilling process is stable, conduct formal drilling according to the experimental plan, and observe and record various parameters in the drilling process in real time, such as torque, propulsion force, and vibration signals; Open the data collection software, record and save various data during the drilling process in real time, organize and analyze the collected data, and calculate the elastic modulus and other mechanical parameters of the sample.

6. A rock damage assessment method based on drilling vibration waveform as claimed in claim 1, characterized in that: In the step S3, a metric model between elastic modulus and vibration parameters is obtained by establishing a random forest model; The steps for constructing the random forest model are as follows: Step A, statistically analyzing the experimental data of the samples obtained in step S2 and step S3, and constructing a data set after data expansion; Step B, preprocessing the input data; Step C, dividing the data set into a training set and a test set; using the training set data to train the random forest model to obtain a random forest model based on vibration parameters; Step D: testing the random forest model based on vibration parameters through a test set.

7. A rock damage assessment method based on drilling vibration waveform as claimed in claim 1, characterized in that: In step A, the experimental data of the samples obtained in steps S2 and S3 may be expanded by using an interpolation method.

8. A rock damage assessment method based on drilling vibration waveform as claimed in claim 1, characterized in that: The step B specifically includes data cleaning and feature scaling. Since different features have different dimensions and ranges, they need to be normalized or standardized to improve the efficiency and accuracy of model training.

9. A rock damage assessment method based on drilling vibration waveform as claimed in claim 1, characterized in that: The data were standardized and normalized using the Min-Max standardization method or the range standardization method.

10. The rock damage assessment method based on drilling vibration waveform according to claim 1, characterized in that: In the step B, the index weights of various vibration parameters are calculated respectively by using the hierarchical analysis method and the coefficient of variation method, and finally the input data is the vibration parameter, and the output data is the elastic modulus regression model, E0=a·v+bv'+cf, wherein v is the vibration velocity, v' is the vibration acceleration, f is the vibration frequency, and a, b, and c are the influence coefficients of each corresponding vibration parameter on the elastic modulus after calculation.

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