Method for detecting and classifying broken range of surrounding rock of underground engineering while drilling

Abstract

The application relates to the technical field of underground engineering and discloses a method for detecting and classifying and evaluating the broken range of surrounding rock of underground engineering while drilling, which belongs to the technical field of underground engineering and comprises the following steps: detecting the surrounding rock in situ while drilling at the roof, shoulder and two sides of a roadway; in the drilling process, four types of parameters while drilling are monitored and obtained by an intelligent geological detection drilling machine, and based on the four types of parameters while drilling, the broken range of the surrounding rock is determined PSO-SVM-RF The neural network model of the particle swarm algorithm can obtain the variation of the mechanical parameters (of the surrounding rock) while drilling in real time σ, E ), and the broken range of the surrounding rock section of the drilling hole is preliminarily determined; sound wave stations are arranged in the section drilling hole while drilling, sound wave detection is carried out, the broken range of the surrounding rock between drilling holes is finely determined according to the variation of the wave velocity between different point positions, and an evaluation index of the broken range of the surrounding rock section is established; according to the evaluation result of the broken surrounding rock section, detection stations-receiving stations are established between different surrounding rock sections, the broken condition of the surrounding rock along the direction of the roadway is detected, and the broken range of the surrounding rock of the roadway is finely and continuously depicted.

Description

Technical Field

[0001] This invention relates to the field of underground engineering technology, and in particular to a method for drilling-while-drilling detection and classification evaluation of the fractured range of surrounding rock in underground engineering. Background Technology

[0002] After excavation of the surrounding rock in underground engineering projects, the ground stress exceeds the strength of the surrounding rock, causing plastic deformation and failure, which in turn forms a loose and fractured zone around the tunnel. The size of the fractured zone directly affects the support design of underground engineering projects; the larger the fractured zone, the more difficult the support. Therefore, detecting the fractured zone is of great significance for tunnel support design and ensuring worker safety.

[0003] Currently, the main methods for on-site detection of fractured areas include borehole photography, ground-penetrating radar, and acoustic detection. Borehole photography involves personnel identifying fractures in borehole images to determine the location and number of fractures within the borehole. The method lacks objective evaluation standards for features such as width; the ground-penetrating radar method indirectly obtains the fracture range of the surrounding rock based on key parameters such as the time and propagation speed of high-frequency electromagnetic waves in the medium, but the detection results of this method are easily affected by the environment. The acoustic detection method involves the detection personnel analyzing the acoustic signals to determine the structural features of the rock mass, such as structural planes and fracture zones. This method requires multiple detections to find the optimal detection point, and the process is relatively cumbersome and inefficient.

[0004] Based on this, the inventors found that the current method for detecting the range of fractured surrounding rock still faces significant technical challenges in practical applications, including a lack of objective evaluation standards, susceptibility of detection results to environmental influences, and relatively complicated construction procedures. Summary of the Invention

[0005] To address the technical problems existing in the prior art, the purpose of this invention is to provide a method for drilling-while-drilling detection and classification evaluation of the fractured range of surrounding rock in underground engineering. This method combines drilling-while-drilling detection with acoustic detection methods. First, an integrated acoustic emission-receiver drill pipe is used to conduct in-situ drilling-while-drilling detection of the surrounding rock, performing multi-point detection within each rock section to initially determine the fractured range of the surrounding rock at the borehole scale. Based on this, the acoustic detection method is combined to clarify the fractured rock conditions between boreholes within the section. Second, detection and receiving stations are established between the rock sections to finely characterize the three-dimensional fractured range of the surrounding rock along the tunnel direction. Finally, a standard for evaluating the fractured range of the surrounding rock is formed, providing data support for the design of surrounding rock support.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The method for detecting and classifying the fractured area of ​​surrounding rock in underground engineering projects during drilling includes the following steps: In-situ drilling exploration was conducted at each roadway rock section to obtain drilling parameters for each section, and the elastic modulus was determined based on these parameters. E With uniaxial compressive strength s ; According to the elastic modulus E With uniaxial compressive strength s The variation of the surrounding rock with drilling depth is used to determine the extent of rock fragmentation within the borehole area; During in-situ drilling exploration, acoustic wave detection is performed on the drilling exploration section to obtain acoustic wave signals; based on the wave velocity change curves between different acoustic wave detection points, the fracture range of the surrounding rock section between boreholes is determined. The boundaries of surrounding rock fracturing are determined based on the fracturing range of the surrounding rock section within the borehole area and the fracturing range of the surrounding rock section between boreholes, and evaluation criteria for surrounding rock fracturing are established based on the boundaries. Based on the evaluation criteria for the extent of rock fracture, acoustic detection stations and receiving stations are established between different sections of the surrounding rock to detect the rock fracture along the direction of the roadway and to finely and continuously characterize the extent of rock fracture in the roadway.

[0007] As a further technical solution, the drilling parameters include drilling pressure. F Drilling torque M Drill bit speed V and drill bit speed N Four types of drilling parameters.

[0008] As a further technical solution, the radial depth of drilling while drilling only needs to reach the elastic modulus. E With uniaxial compressive strength s Significant changes have occurred, with borehole locations arranged symmetrically based on the assumption that the roadway is symmetrical about its geometric central axis.

[0009] As a further technical solution, the acquired drilling parameters are input into the pre-set parameters inside the drilling rig. PSO-SVM- RF A neural network model based on particle swarm optimization is used to calculate the elastic modulus of surrounding rock. E With uniaxial compressive strength s The prediction.

[0010] As a further technical solution, the acoustic wave detection uses an integrated acoustic emission-reception drill pipe for acoustic wave detection.

[0011] As a further technical solution, after the acoustic emission-receiver integrated drill pipe is drilled to a specified depth, the acoustic wave detection method test is carried out directly in situ. An ultrasonic emission station is set up at the geometric center of the roadway roof as the drilling point, and ultrasonic receiving stations are set up at the geometric center points of the two corners and two sides of the roadway as the drilling point.

[0012] As a further technical solution, the acoustic detection is arranged according to the fracture range obtained from the in-situ detection of the surrounding rock. In the transmitting station, the ultrasonic transmitting device at the top of the integrated acoustic emission and receiving drill rod is arranged inside and outside the fracture critical range obtained from the in-situ detection of the surrounding rock; in the receiving station, the ultrasonic receiver at the top of the integrated acoustic emission and receiving drill rod is placed on the boundary of the fracture critical range obtained from the in-situ detection of the surrounding rock.

[0013] As a further technical solution, the surrounding rock fracturing evaluation standard is as follows: If the radial distance H from the boundary of the fractured surrounding rock to the borehole opening is a~bm, it is called stable surrounding rock; If the radial distance H from the borehole opening to the boundary of the fractured surrounding rock is b~cm, it is called general surrounding rock; If the radial distance H from the boundary of the fractured surrounding rock to the borehole opening is H = c ~ dm, it is called unstable surrounding rock; If the radial distance H from the borehole opening to the boundary of the fractured surrounding rock is greater than or equal to dm, it is called extremely unstable surrounding rock; Where a≤b≤c≤d, and a, b, c, and d are the set distance values, and m is the distance unit meter.

[0014] As a further technical solution, the method of establishing a detection station-receiving station between cross sections in step 4 adopts the double-hole method. A sound wave transmitting station is set on the roof of the roadway in this cross section, on one side of the shoulder and on the sidewall on the same side of the shoulder, and a sound wave receiving station is set at the same location in the next cross section.

[0015] As a further technical solution, the relative distance between monitoring stations at different cross-sections should be determined according to the aforementioned evaluation criteria for the range of surrounding rock fracturing, including: If the current section is rated as stable surrounding rock, the relative distance to the next section can be ≤ em; If the current section is rated as general surrounding rock, then the relative distance to the next section can be ≤fm; If this section is rated as unstable surrounding rock, then the relative distance to the next section can be ≤gm; If this section is rated as extremely unstable surrounding rock, then the relative distance to the next section can be ≤hm; Where: e≥f≥g≥h; and e, f, g, and h represent the set distance values, and m is the distance unit meter.

[0016] The beneficial effects of the present invention are as follows: This invention proposes a method for detecting and classifying the fractured rock range in underground engineering during drilling. It combines drilling-while-drilling (DWD) and acoustic detection methods. Acoustic detection is conducted in situ during DWD, performing multi-point DWD and acoustic detection within each cross-section to define the fractured rock range within that section. Acoustic detection is then performed between different cross-sections, connecting the detection surfaces to form a three-dimensional fractured rock range within a spatial area, accurately characterizing the fractured rock range of the tunnel. Furthermore, this invention can simultaneously acquire surrounding rock parameters and detect the fractured range. Based on the evaluation results of the surrounding rock fracture level, acoustic detection and receiving stations are set up between cross-sections to ultimately measure the complete fractured rock range of the tunnel. The method is simple, highly operable, and low-cost. This invention requires no drainage or ventilation ducts and is unaffected by factors such as borehole collapse, ensuring operation even in geological conditions with fractured surrounding rock. It has a significant impact on improving work efficiency and saving manpower and resources. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention: the illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.

[0018] Figure 1 This is the technical roadmap of the present invention.

[0019] Figure 2 It is a roadmap for the technology of built-in models in intelligent geological drilling rigs.

[0020] Figure 3 This is a schematic diagram of the acoustic emission-receiver integrated drill rod described in this invention; Figure 4 This is a schematic diagram of the tunnel layout for the method of drilling-while-drilling detection and classification evaluation of the fracture range of surrounding rock in underground engineering according to one or more embodiments of the present invention. Figure 5 This is a schematic diagram of the cross-sectional borehole layout for the method of detecting and classifying the fractured range of surrounding rock in underground engineering according to one or more embodiments of the present invention.

[0021] In the diagram, 1. Preamplifier; 2. Acoustic wave transmitter; 3. Circuit fuse; 4. Filter unit; 5. Signal demodulation unit; 6. Electromagnetic driver; 7. Power amplifier; 8. Acoustic wave receiver; 9. Main control unit; 10. Valve; 11. Pressure sensor; 12. Valve controller; 13. Liquid bladder; 14. Detection section; 15. Detection borehole; 16. Acoustic wave transmitter station; 17. Acoustic wave receiver station; 18. Breaking range. Detailed Implementation The technical solution of the present invention will be further described in a complete and clear manner below with reference to the accompanying drawings and examples.

[0022] The following detailed description is exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] As described in the background section, existing methods for detecting rock fracture are diverse and applicable to construction environments such as tunnels and roadways. However, mainstream detection methods are easily affected by the environment and heavily rely on the experience of the detection personnel, making subjectivity a significant factor that can lead to misjudgments and errors. Therefore, this embodiment proposes a method for detecting and classifying the fracture range of surrounding rock in underground engineering during drilling. This invention enables the detection of the fracture range of surrounding rock during drilling, using data as a benchmark, models as a bridge, and results as facts, reducing the influence of subjectivity and providing rapid and accurate data support for the design of surrounding rock support in underground engineering.

[0024] Specifically, the method for detecting and classifying the fractured area of ​​surrounding rock in underground engineering provided in this embodiment includes the following steps: Step 1: Conduct in-situ drilling exploration of the surrounding rock at the roof, shoulder, and both sides of each roadway section to obtain the drilling parameters for each section. Determine the elastic modulus based on these drilling parameters. E With uniaxial compressive strength s ; Step 2: Based on the elastic modulus E With uniaxial compressive strength s The variation with drilling depth is used to determine the borehole range. The extent of fracture in the surrounding rock section; Step 3: During the in-situ drilling exploration process, acoustic wave detection is performed on the drilling exploration section to obtain acoustic wave signals; based on the wave velocity change curves between different points, the fracture range of the surrounding rock section between boreholes is determined; specifically, acoustic wave stations are set up on the drilling exploration section, and acoustic wave detection is performed using an integrated acoustic emission-reception drill pipe. After water injection and air venting, acoustic waves are released, and acoustic wave signals are received in adjacent boreholes of this section using an integrated acoustic emission-reception drill pipe. Step 4: Determine the boundaries of the surrounding rock fracture based on the fracture range of the surrounding rock section within the borehole area and the fracture range of the surrounding rock section between boreholes, and establish the evaluation criteria for the surrounding rock fracture based on the boundaries. Step 5: Based on the evaluation criteria for the range of rock fracture, establish acoustic detection stations and receiving stations between different sections of the surrounding rock to detect the rock fracture along the direction of the roadway and to finely and continuously delineate the range of rock fracture in the roadway.

[0025] The aforementioned method for detecting and classifying the fractured rock range in underground engineering combines drilling-while-detection (DWW) and acoustic detection methods. Acoustic detection is conducted in situ during DWW, performing multi-point DWW and acoustic detection within each cross-section to define the fractured rock range within that section. Acoustic detection is then performed between different cross-sections, connecting the detection surfaces to form a three-dimensional fractured rock range within a spatial area, accurately depicting the fractured rock range of the tunnel. Furthermore, this invention can simultaneously acquire surrounding rock parameters and detect the fractured range. Based on the evaluation results of the surrounding rock fracture level, acoustic detection and receiving stations are set up between cross-sections, ultimately measuring the complete fractured rock range of the tunnel. The method is simple, highly operable, and low-cost. The following detailed description of each step in this invention is provided with reference to the accompanying drawings: In the drilling exploration method in step 1 above, an intelligent geological exploration drilling rig is mainly used to conduct in-situ drilling exploration of the surrounding rock in the tunnel roof, shoulder, and both sides to obtain four types of drilling parameters; the elastic modulus of the surrounding rock is determined based on the obtained four types of drilling parameters. E With uniaxial compressive strength s Then, during the drilling process, the intelligent geological exploration drilling rig acquires real-time data on the surrounding rock. E and s Determine the extent of rock fracture in the cross section based on the changes in drilling depth; Specifically, the above four types of drilling parameters refer to drilling pressure ( F ), drilling torque ( M ), Drill bit speed ( V ) and drill bit speed ( N ); Specifically, the intelligent geological exploration drilling rig includes the following subsystems: a drilling system, a hydraulic servo system, a monitoring and control system, and a detection auxiliary system, used for real-time monitoring of drilling parameters; the intelligent geological exploration drilling rig senses data in real time during the exploration process and inputs it into the rig's internal preset parameters. PSO-SVM-RF Particle swarm optimization neural network model for surrounding rock E and s Make predictions.

[0026] During the drilling process, the intelligent geological exploration drilling rig acquires real-time data on the surrounding rock. E and s As drilling depth changes, the extent of rock fracture in the surrounding rock section is determined; specifically, the radial depth of drilling probes only needs to reach the elastic modulus. E With uniaxial compressive strength sSignificant changes occurred. Drilling points were symmetrically arranged based on the assumption of symmetry about the geometric center axis of the tunnel. The method for judging significant changes is as follows: The standard deviation method is used to find the upward trend of the curve. When drilling is in a stable section, the mean and standard deviation are calculated. The vast majority of points should fall within the mean plus three standard deviations (the standard normal distribution assumes 99.85% of the data should fall within this interval). If a point's value falls outside the mean plus three standard deviations, that point is recorded. As drilling progresses, the mean plus three standard deviations for the subsequent segment is calculated. If the point's value also falls outside this segment, it is considered an outlier, and no upward trend is found in the curve. If the point's value falls within this segment, an upward trend is found in the curve, and a significant change is recorded.

[0027] Furthermore, the pre-set model inside the drilling rig is based on PSO-SVM-RF The specific implementation steps of the neural network model for the particle swarm optimization algorithm are as follows: 1. On-site detection and monitoring yielded results. F、M、N and V Four types of drilling parameters and corresponding surrounding rock conditions. E and s They are divided into a test set and a validation set; 2. Input the test set PSO-SVM-RF The neural network model of the particle swarm optimization algorithm was trained to obtain four types of drilling parameters and surrounding rock. E and s The correspondence; 3. Input the four types of drilling parameters from the validation set to obtain the predicted surrounding rock. E and s The predicted difference rate is obtained by comparing it with the actual value. x And evaluate the prediction results; 4. If x If the rate is ≤15%, the model training effect is considered to be good; otherwise, the training effect is considered to be unsatisfactory, and a second round of checking will be conducted. 5. Apply statistical testing methods K Cross-validation is used to test the model for fit, and there are two cases: overfitting and underfitting. Overfitting: Use ensemble methods to preprocess the data to reduce the possibility of the model over-selecting numerical features; Underfitting: Use regularization to preprocess the data to improve the extraction of numerical features and reduce the number of invalid numbers detected by the model.

[0028] 6. Repeat the above steps.

[0029] Specifically, PSOIt is a swarm intelligence-based optimization algorithm that simulates animal herding behavior. Through collaboration and information exchange between individual data points / data collections, it autonomously finds the optimal solution in space; it includes the following steps: 1. Initialize the input data for particles / particle swarms, setting the quantity, position, search space dimension, and number of iterations. Taking drilling parameters as an example: the data volume is n×4 (each hole has four types of drilling parameters with the same data volume, and the number of each data volume is n), and the number of particles is set accordingly. Secondly, the particle position adopts the random uniform initialization method, that is, random uniform sampling in each dimension, which is determined by the user. Thirdly, since there are four different types of drilling parameters, the search space dimension is 4. Finally, the number of iterations is determined by the experience of the probe personnel, and is tentatively set to 100.

[0030] 2. Iterative update; taking drilling parameters as an example: iterative optimization of four types of numerical features, namely “mean”, “variance”, “sample entropy” and “dominant frequency”, is performed on all four types of drilling parameters. This mainly includes “calculating the current fitness”, “updating the current individual optimum”, “updating the current global optimum” and “updating particle velocity and position”.

[0031] 3. Set termination conditions to reach the initial set number of iterations. Taking drilling parameters as an example: the feature extraction of the four types of drilling parameters will eventually stop automatically after reaching the maximum number of iterations.

[0032] Specifically, SVM-RF Combined with support vector machine ( SVM ) and Random Forest ( RF This is a hybrid machine learning algorithm that combines the advantages of both methods to improve the efficiency of regression tasks. It includes the following steps: 1. Based on RF Feature selection: using RF The model calculates the importance of features in the training data, sorts them by importance, selects the top 20% of features, and reduces the dimensionality of the data. 2. SVM Modeling and optimization: using RF The training set is reconstructed using the numerical features in the dataset, a linear kernel is selected for computation, and finally, the results are verified. SVM The hyperparameter situation.

[0033] Specifically, K Fold-down validation is a statistical method for evaluating the generalization ability of machine learning models by dividing the dataset into... K Each subset ("fold") is used cyclically. K -1 fold is used as the training set, and the remaining 1 fold is used as the test set. Finally, the results are combined... K The results were stable.

[0034] Specifically, the ensemble method is an algorithm that uses diversity to reduce contrast, improve generalization ability, and reduce the over-reliance of a single model on training data.

[0035] Specifically, regularization is a strategy used in machine learning and deep learning to prevent model overfitting and improve generalization ability.

[0036] Specifically, the predicted variance rate x The calculation formula is as follows:

[0037] Furthermore, in step 3 above, an acoustic wave station is set up at the drilling detection section, and acoustic wave detection is performed using an integrated acoustic emission-reception drill pipe. After water injection and air venting, acoustic waves are released, and acoustic wave signals are received in adjacent boreholes at the same section using an integrated acoustic emission-reception drill pipe.

[0038] Specifically, in this embodiment, the drilling detection bit and the acoustic station are integrated on a single drill rod, which is installed on the intelligent geological exploration drilling rig. The acoustic receiving and transmitting station and the control unit are integrated between the drill rod and the drill bit. The acoustic detection is performed after the drilling work of the drill rod is completed, that is, the acoustic detection is performed in a static environment. The main components of the acoustic emission-reception integrated drill pipe in this embodiment include: an acoustic wave receiver, an emission station, and a control unit. The acoustic wave receiver and emission unit are fixedly connected to the drill pipe. An ultrasonic transmitter is installed at the top of the drill pipe, and an ultrasonic transmitter is arranged every 30cm along the drill pipe, for a total of three ultrasonic emission devices. An ultrasonic receiver is symmetrically arranged at the top of the drill pipe. The main unit is equipped with a device control unit to control the drilling process of the drill pipe and to connect the ultrasonic transmitter and ultrasonic receiver with unit signals.

[0039] Specifically, the acoustic wave receiving and transmitting station and control unit includes a preamplifier 1, an acoustic wave transmitter 2, a circuit fuse device 3, a filtering unit 4, a signal demodulation unit 5, an electromagnetic driver 6, a power amplifier 7, an acoustic wave receiver 8, a main control unit 9, a valve 10, a pressure sensor 11, a valve controller 12, and a liquid bladder 13. Taking the receiving operation as an example, the specific working process is explained as follows: During reception: The main control unit 9 receives the "transmit sound wave" command and transmits the "close valve" command signal, which reaches the valve controller 12 via the signal line. The valve controller 12 then sends "close" and "open" commands, which reach the electromagnetic driver 6 via the filter unit 4 and the power amplifier 7, closing the drill pipe water channel valve and simultaneously opening the valves of the two liquid bladders 13. When the water volume in the liquid bladders 13 reaches the predetermined value, the pressure sensor 11 transmits a signal to the valve controller 12. The valve controller 12 then sends a "close" command, which reaches the electromagnetic driver 6 via the filter unit 4 and the power amplifier 7, closing the valves of the two liquid bladders 13. Subsequently, the valve controller 12 sends a "completed" signal to the main control unit 9. Immediately afterwards, the main control unit 9 sends a "transmit" command, which reaches the sound wave receiver 8 via the signal demodulation unit 5 and the filter unit 4.

[0040] Specifically, the radial drilling depth only needs to reach E and s Significant changes have occurred. The drilling points are symmetrically arranged based on the assumption that the roadway is symmetrical about its geometric center axis. There are a total of 5 working points in a single cross section, including: the roadway roof, shoulder and both sides, to carry out in-situ drilling exploration of the surrounding rock.

[0041] Specifically, after the acoustic emission-receiver integrated drill pipe has been drilled to a specified depth, it does not need to be withdrawn and can be directly tested using the acoustic detection method. An ultrasonic transmitting station is set up at the geometric center of the roadway roof as the drilling point, and ultrasonic receiving stations are set up at the geometric center points of the two corners and two sides of the roadway as the drilling point.

[0042] Specifically, the acoustic testing stations are arranged according to the fracture range obtained from in-situ detection of the surrounding rock. This includes: in the transmitting station, the ultrasonic transmitting device at the top of the integrated acoustic emission and receiving drill rod is positioned both inside and outside the critical fracture range obtained from in-situ detection of the surrounding rock; in the receiving station, the ultrasonic receiver at the top of the integrated acoustic emission and receiving drill rod is placed on the boundary of the critical fracture range obtained from in-situ detection of the surrounding rock. Specifically, two detections are performed during boundary detection. The specific operating procedure is as follows: 1. During the first detection, the ultrasonic transmitter is located inside the critical fracture range obtained from the in-situ detection of the surrounding rock, and the ultrasonic receiver is placed on the boundary of the critical fracture range obtained from the in-situ detection of the surrounding rock. 2. During the second detection, the ultrasonic transmitter was located outside the critical range of fracture obtained from the in-situ detection of the surrounding rock, and the ultrasonic receiver was placed on the boundary of the critical range of fracture obtained from the in-situ detection of the surrounding rock.

[0043] 3. Compare the results of the two acoustic detections, analyze the critical range of breakage, and clarify the differences in structural characteristics between the inside and outside of the critical range of breakage.

[0044] The first acoustic wave detection is conducted inside the critical fracture zone to detect the structural features within the critical fracture zone and accurately determine the critical fracture zone. The second acoustic wave detection is conducted outside the critical fracture zone to detect the structural features outside the critical fracture zone and accurately determine the critical fracture zone.

[0045] Specifically, the cross-sectional fracture range detection uses the dual-hole method, which involves measuring the propagation time of sound waves in the rock mass, calculating the wave velocity, and analyzing the fracture range. The specific operation procedure is as follows: 1. Arrange the measuring station to the designated depth according to the in-situ borehole, and fill the liquid bladder with water at the same time; 2. Data acquisition is performed using the transmitting and receiving units of each station; 3. Process the collected data according to the formula:

[0046] in, For longitudinal wave velocity, This is the distance between adjacent cross sections. This refers to the time taken from the transmission of sound waves to the reception.

[0047] 4. The wave velocity of intact rock mass is faster than that of fractured rock mass. By measuring the change in wave velocity of the rock mass between two boreholes, the depth and extent of the fracture can be determined.

[0048] Specifically, the degree of fragmentation described in this detection method includes the following four levels, as follows, and the following description... The radial distance is in the direction of drilling depth; 1. The boundary of the finely fractured area obtained by in-situ detection and acoustic detection of the surrounding rock, with a radial distance of H=a~bm from the borehole opening, is called Class A (stable surrounding rock). The surrounding rock of this class of roadway is less affected by disturbance and the rock mass is intact. 2. The boundary of the finely fractured area obtained by in-situ detection and acoustic detection of the surrounding rock, with a radial distance of H = b~cm from the borehole opening, is called Class B (general surrounding rock). The surrounding rock of this class of roadway is generally not affected by disturbance and the rock mass is relatively intact. 3. The boundary of the fine fracture range obtained by in-situ detection and acoustic detection of the surrounding rock, with a radial distance of H = c ~ dm from the borehole opening, is called Class C (unstable surrounding rock). The surrounding rock of this class of roadway is greatly affected by disturbance and the rock mass is relatively fractured. 4. The boundary of the fine fracture range obtained by in-situ detection and acoustic detection of the surrounding rock, with a radial distance H ≥ dm from the borehole opening, is called Class D (extremely unstable surrounding rock). The surrounding rock of this class of roadway is greatly affected by disturbance and the rock mass is fractured. It may pass through fracture zone or soft rock zone. Wherein, a≤b≤c≤d, and a, b, c, and d are the set distance values. These four distance values ​​can be obtained by combining a large number of field tests, referring to actual project data, and consulting historical disaster data.

[0049] Furthermore, based on the evaluation results, detection stations and receiving stations are established between different sections of the surrounding rock to detect the fracturing of the surrounding rock along the direction of the roadway and to finely and continuously delineate the range of fracturing of the surrounding rock in the roadway.

[0050] Specifically, the fine characterization of fracture between cross sections is achieved using the dual-hole method. Specifically, transmitting stations are set up on the roof of the roadway, the shoulder on one side, and the sidewall on the same side of the shoulder in this cross section, and receiving stations are set up at the same location in the next cross section. The specific usage method is the same as the steps of the acoustic detection method for the fracture range of cross sections. The "same location" mentioned here means: the receiving stations are set up on the roof of the roadway on the same side of the roadway in the next cross section, the shoulder on one side, and the sidewall on the same side of the shoulder, and the measuring points of different cross sections are aligned front and back in all directions.

[0051] Specifically, the fracture range between cross sections is measured only on one side, and the other side is compared according to the symmetry assumption to obtain the fracture range state of the entire cross section.

[0052] Specifically, the relative distances between stations at different cross-sections should be determined according to the levels obtained from the above-mentioned grading method, including: If this section is rated as Class A, then the relative distance to the next section can be ≤ em; If this section is rated as Class B, then the relative distance to the next section can be ≤fm; If this cross-section is rated as Class C, then the relative distance to the next cross-section can be ≤ gm; If this cross-section is rated as Class D, then the relative distance to the next cross-section can be ≤hm; Where: e≥f≥g≥h; and e, f, g, and h represent the set distance values ​​respectively. The geological conditions of the tunnel are complex and varied. When applying this method, the values ​​of e, f, g, and h can be obtained by referring to the surrounding rock classification evaluation standard, combining a large number of field tests, referring to the actual data of the project, and consulting historical disaster data.

[0053] Based on the wave velocity variation curves between different points, the extent of rock fracturing in the cross-section is precisely determined, and the degree of rock fracturing is evaluated, establishing an evaluation standard for the extent of rock fracturing. Specifically, the evaluation standards between cross-sections are as follows: Specifically, the degree of fragmentation described in this detection method includes the following four levels: The boundary of the fine fracture range obtained by in-situ detection and acoustic detection of the surrounding rock, with a radial distance of H=a~bm from the borehole opening, is called Class A (stable surrounding rock). The surrounding rock of this class of roadway is less affected by disturbance and the rock mass is intact. The boundary of the fine fracture range obtained by in-situ detection and acoustic detection of the surrounding rock, with a radial distance of H=b~cm from the borehole opening, is called Class B (general surrounding rock). The surrounding rock of this class of roadway is generally not affected by disturbance and the rock mass is relatively intact. The boundary of the fine fracture range obtained by in-situ detection and acoustic detection of the surrounding rock, with a radial distance of H=c~dm from the borehole opening, is called Class C (unstable surrounding rock). The surrounding rock of this class of roadway is greatly affected by disturbance and the rock mass is relatively fractured. The boundary of the fine fracture range obtained by in-situ detection and acoustic detection of surrounding rock, with a radial distance H ≥ dm from the borehole opening, is called Class D (extremely unstable surrounding rock). The surrounding rock of this class of roadway is greatly affected by disturbance and the rock mass is fractured. It may pass through fracture zone or soft rock zone. The condition is a≤b≤c≤d, where a, b, c, and d are set distance values.

[0054] In summary, the method for detecting and classifying the fractured range of surrounding rock in underground engineering proposed in this embodiment combines drilling-while-detection (DWW) and acoustic detection methods. Acoustic detection is conducted in situ during DWW, with multiple points of DWW and acoustic detection performed within each cross-section to form the fractured range of the surrounding rock cross-section. Then, acoustic detection is performed between different cross-sections, connecting the detection surfaces to form a three-dimensional fractured range of surrounding rock within a spatial range, accurately depicting the fractured range of the surrounding rock in the tunnel. Furthermore, this invention can simultaneously acquire surrounding rock parameters and detect the fractured range. Based on the evaluation results of the fractured range level, acoustic detection stations and receiving stations are set between cross-sections, ultimately measuring the complete fractured range of the surrounding rock in the tunnel. The method is simple, highly operable, and low in cost.

Claims

1. A method for drilling-while-testing and classifying the fractured area of ​​surrounding rock in underground engineering, characterized in that, as follows: In-situ drilling exploration was conducted at each roadway rock section to obtain drilling parameters for each section, and the elastic modulus was determined based on these parameters. E With uniaxial compressive strength σ ; According to the elastic modulus E With uniaxial compressive strength σ The variation of the surrounding rock with drilling depth is used to determine the extent of rock fragmentation within the borehole area; During in-situ drilling exploration, acoustic wave detection is performed on the drilling exploration section to obtain acoustic wave signals; based on the wave velocity change curves between different acoustic wave detection points, the fracture range of the surrounding rock section between boreholes is determined. The boundaries of the surrounding rock fracture range are determined based on the fracture range of the surrounding rock cross section within the borehole area and the fracture range of the surrounding rock cross section between boreholes, and the evaluation criteria for surrounding rock fracture are established based on the boundaries. Based on the evaluation criteria for the extent of rock fracture, acoustic detection stations and receiving stations are established between different sections of the surrounding rock to detect the rock fracture along the direction of the roadway and to finely and continuously characterize the extent of rock fracture in the roadway.

2. The method for drilling-while-drilling detection and classification evaluation of the fractured area of ​​surrounding rock in underground engineering according to claim 1, characterized in that, The drilling parameters include drilling pressure. F Drilling torque M Drill bit speed V and drill bit speed N Four types of drilling parameters.

3. The method for drilling-while-drilling detection and classification evaluation of the fractured area of ​​surrounding rock in underground engineering according to claim 1, characterized in that, While drilling, the radial depth of the drilled part only needs to reach the elastic modulus. E With uniaxial compressive strength σ Significant changes have occurred, with borehole locations arranged symmetrically along the geometric center axis of the roadway.

4. The method for drilling-while-drilling detection and classification evaluation of the fractured area of ​​surrounding rock in underground engineering according to claim 1, characterized in that, The acquired drilling parameters are input into the preset parameters inside the drilling rig. PSO-SVM-RF A neural network model based on particle swarm optimization is used to calculate the elastic modulus of surrounding rock. E With uniaxial compressive strength σ The prediction.

5. The method for drilling-while-drilling detection and classification evaluation of the fractured area of ​​surrounding rock in underground engineering according to claim 1, characterized in that, The acoustic detection method employs an integrated acoustic emission and reception drill pipe for acoustic detection.

6. The method for drilling-while-drilling detection and classification evaluation of the fractured range of surrounding rock in underground engineering according to claim 5, characterized in that, After the acoustic emission-receiver integrated drill pipe is drilled to a specified depth, acoustic wave detection tests are carried out directly in situ. Ultrasonic emission stations are set up at the drilling detection points at the geometric center of the roadway roof, and ultrasonic receiving stations are set up at the drilling detection points at the geometric center of the two corners and two sides of the roadway.

7. The method for drilling-while-drilling detection and classification evaluation of the fractured area of ​​surrounding rock in underground engineering according to claim 6, characterized in that, The acoustic detection is arranged according to the fracture range obtained from the drilling detection of the surrounding rock. The ultrasonic transmitter at the top of the drill pipe is arranged inside and outside the fracture critical range obtained from the in-situ detection of the surrounding rock; the ultrasonic receiver at the top of the drill pipe is placed on the boundary of the fracture critical range obtained from the in-situ detection of the surrounding rock.

8. The method for drilling-while-drilling detection and classification evaluation of the fractured area of ​​surrounding rock in underground engineering according to claim 1, characterized in that, The evaluation criteria for surrounding rock fracturing are as follows: If the radial distance H from the boundary of the fractured surrounding rock to the borehole opening is a~bm, it is called stable surrounding rock; If the radial distance H from the borehole opening to the boundary of the fractured surrounding rock is b~cm, it is called general surrounding rock; If the radial distance H from the boundary of the fractured surrounding rock to the borehole opening is H = c ~ dm, it is called unstable surrounding rock; If the radial distance H from the borehole opening to the boundary of the fractured surrounding rock is greater than or equal to dm, it is called extremely unstable surrounding rock; Where a≤b≤c≤d, and a, b, c, and d are the set distance values, and m is the distance unit meter.

9. The method for drilling-while-drilling detection and classification evaluation of the fractured range of surrounding rock in underground engineering according to claim 8, characterized in that, The method of establishing a detection station-receiving station between cross sections adopts the double-hole method. Acoustic wave transmitting stations are set up on the roof, shoulder and sidewall of the roadway in this cross section, and acoustic wave receiving stations are set up at the same positions in the next cross section.

10. The method for drilling-while-drilling detection and classification evaluation of the fractured area of ​​surrounding rock in underground engineering according to claim 8, characterized in that, The relative distance between monitoring stations at different cross-sections should be determined according to the aforementioned evaluation criteria for surrounding rock fracturing, including: If the current section is rated as stable surrounding rock, the relative distance to the next section shall be ≤ em; If this section is rated as general surrounding rock, then the relative distance to the next section is ≤fm; If this section is rated as unstable surrounding rock, then the relative distance to the next section is ≤ gm; If this section is rated as extremely unstable surrounding rock, then the relative distance to the next section is ≤hm; Where: e≥f≥g≥h; and e, f, g, and h represent the set distance values, and m is the distance unit meter.

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