Method for collecting and analyzing mine surrounding rock loose circle anomaly map based on geological radar

Abstract

The application discloses a kind of based on geological radar mine surrounding rock loose circle abnormal atlas collection and analysis method, it is related to underground mine rock mechanics technical field.The method includes: selecting surface flat and part area containing anchor rod test rock wall;Geological radar probe is controlled on test rock wall, respectively with four kinds of non-ideal state movement of probe intermittent void due to uneven rock wall, metal anchor interference, non-vertical angle movement, vibration caused by the influence of rock wall smooth degree, four kinds of typical abnormal characteristic atlas are collected and calibrated as reference;Then, the conventional detection is carried out to the rock wall to be measured, the measured atlas obtained is compared with the abnormal atlas, the abnormal characteristic points matched with the characteristic points of the abnormal atlas are removed, and the size of the loose circle is judged.The application effectively solves the problem of misjudgment of the loose circle caused by the condition of the rock wall or the deviation of the operation, and significantly improves the detection accuracy and efficiency.

Description

Technical Field

[0001] This invention relates to the field of rock mechanics technology in underground mines, specifically to a method for collecting and analyzing anomaly maps of loosened zones in surrounding rock in mines based on ground-penetrating radar. Background Technology

[0002] The loosened zone is a core concept in rock engineering, specifically referring to the annular fracture zone formed after the excavation of underground engineering structures such as mine roadways, stopes, or chambers, where the local stress level exceeds the ultimate strength of the rock mass due to the combined effects of initial stress release and secondary stress redistribution. In roadway support theory, the thickness and extent of the loosened zone directly determine the stability of the surrounding rock and the support requirements: anchor bolts must penetrate the loosened zone, anchoring their bearing ends to a relatively intact, self-supporting elastic zone or the original rock stress zone outside the loosened zone to form an effective bearing arch structure, thereby mobilizing the self-supporting capacity of the deep surrounding rock. Therefore, accurate measurement of the loosened zone size is a prerequisite for the scientific design of parameters such as anchor bolt length, spacing, and support strength, directly affecting the safety and economy of mine production.

[0003] In the field of loosening zone testing technology, various detection methods have been developed over a long period, mainly including ultrasonic methods, borehole imaging methods, and ground-penetrating radar (GPR). The core of GPR is to utilize the scattering characteristics of seismic waves to perform high-resolution imaging of the subsurface medium. It artificially generates seismic waves, which, when propagating underground, encounter anomalies such as fissures, fracture zones, cavities, and isolated boulders—objects with different wave velocities and densities compared to the surrounding medium—resulting in scattering phenomena. GPR systems employ a small-interval, short-array, dense-reception observation method, deploying multiple detectors on the surface or within tunnels to simultaneously receive reflected and scattered wave signals from different directions underground. Subsequently, the system uses proprietary algorithms to process these complex wave fields, reconstructing the wave velocity structure and geological interface images of the subsurface medium. By identifying differences in spectral color levels, the location, shape, and scale of the loosening zone can be accurately located and delineated. The basic rule for judging the size of the loosening zone using grayscale color levels is: the higher the color level, the brighter the surrounding rock; the lower the color level, the darker the surrounding rock. The boundary between the bright and dark color levels is the boundary of the loosening zone. Although ground-penetrating radar (GPR) has significant technical advantages, its practical application also exhibits prominent sensitivity and limitations. The most critical drawback lies in its strong interference response to the smoothness of the rock surface being measured and to anomalies such as metal components and anchor bolts already installed within the tunnel. When the seismic waves emitted by GPR encounter uneven rock walls, metal objects, or other anomalies, they generate anomaly maps, which become mixed with the map of the loosening zone. Furthermore, the bright color levels of the anomaly map are typically larger than those of the normal loosening zone map, thus affecting the final identification of the loosening zone size and leading to problems such as unreasonable support design parameters.

[0004] Currently, the identification and removal of the aforementioned metal interference anomaly maps in engineering practice still mainly relies on the personal experience of professionals for manual removal, lacking objective, unified quantitative standards and repeatable operational procedures. Existing technologies lack specialized methods for the acquisition, feature analysis, and intelligent identification of ground-penetrating radar (GPR) anomaly maps of loosened rock zones in mines. Therefore, it is necessary to design a method for acquiring and analyzing mine surrounding rock loosened zone anomaly maps based on GPR, thereby scientifically determining the specific scope of support design, effectively guiding on-site construction, and truly solving the aforementioned technical challenges. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present invention provides a method for collecting and analyzing anomaly maps of loosened zone in mine surrounding rock based on ground-penetrating radar. By selecting typical rock walls and conducting loosened zone tests with ground-penetrating radar, the operation process under different anomaly conditions is simulated, the color gradation changes of the anomaly maps read under different simulated conditions are analyzed, and typical features such as the shape and brightness of the anomaly maps are recorded. These are used as reference samples for comparative analysis between anomaly maps and normal maps, and are used to remove anomaly maps in the loosened zone test results, thereby improving the accuracy and precision of loosened zone testing.

[0006] This invention provides a method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, comprising the following steps: S1, Test location selection: The rock wall surface at the test location is flat and divided into anchor-supported area and unsupported area; S2, Anomaly Map Calibration: At the selected test location, the measurement state of the ground-penetrating radar probe is manually controlled to simulate various typical abnormal measurement conditions caused by uneven rock walls, electromagnetic interference from metals, abnormal probe measurement posture, or probe vibration caused by the smoothness of the rock wall during the loosening zone measurement process. Anomaly feature maps under each typical abnormal geological structure measurement condition are collected to establish an anomaly feature map reference library. S3, Loosening Zone Measurement: Ground-penetrating radar scan is performed on the rock wall to be tested to obtain the measured map; S4, Abnormal Feature Comparison and Removal: The measured map is compared with the abnormal feature map reference library to identify and remove abnormal feature points in the measured map that correspond to the abnormal feature map. S5, Loosening Zone Determination: Based on the measured map after removing abnormal feature points, the range of the loosening zone of the surrounding rock is determined by analysis.

[0007] As a further improvement of the present invention, in step S2, the various typical abnormal geological structure measurement conditions include: The abnormal coupling state between the probe and the rock wall surface is simulated by controlling the contact / intermittent detachment state between the probe and the rock wall surface. Abnormal electromagnetic interference with metals was simulated by setting metal anchors along the probe's measurement path. The probe's abnormal posture is simulated by changing the spatial angle of the probe relative to the rock wall surface; and The abnormal movement of the probe was simulated by changing the probe's moving speed and applying external vibrations of different frequencies.

[0008] As a further improvement of the present invention, in step S2, each simulation measurement changes only one measurement state to simulate a single typical abnormal geological structure measurement condition, while keeping other measurement states at standard measurement conditions, so that a single variable correspondence is formed between each abnormal feature map and the abnormal measurement conditions.

[0009] As a further improvement of the present invention, in step S1, the support area is provided with metal anchors arranged in rows, and there are no other metal components on the rock wall surface except for the metal anchors.

[0010] As a further improvement of the present invention, in step S1, the rock wall is a flat rock wall with a length of not less than 3m and a width of not less than 2m; the number of metal anchors is not less than 3, and they are arranged in a regular manner, and the exposed length of the anchors meets the measurement requirements of the ground-penetrating radar probe when it moves past the anchors.

[0011] As a further improvement of the present invention, in step S4, the measured map is matched with each abnormal feature map in the abnormal feature map reference library one by one. When the similarity between a local feature in the measured map and any abnormal feature map reaches a preset threshold, the local feature is determined to be an abnormal feature and is removed.

[0012] As a further improvement of the present invention, in step S2, the measurement of abnormal coupling between the probe and the rock wall surface is achieved by intermittently detaching the probe in the following way: the probe is moved slowly perpendicular to the surface of the unsupported area of ​​the rock wall, and after moving a certain distance, the probe is lifted manually to detach it from the rock wall, thereby simulating the real working condition that the probe is not attached to the rock wall or that the probe is intermittently detached from the rock wall due to the unevenness of the rock wall.

[0013] As a further improvement of the present invention, in step S2, the measurement of abnormal metal electromagnetic interference is as follows: the probe is moved slowly perpendicular to the surface of the rock wall anchor support area, and passes through at least three metal anchors during the movement, so as to simulate the working condition when the probe detects the influence of the metal anchors.

[0014] As a further improvement of the present invention, in step S2, the abnormal probe measurement posture measurement is performed by moving the probe at multiple different non-zero angles to the surface of the unsupported rock wall, thereby simulating the working condition when the probe is not perpendicular to the measured rock wall.

[0015] As a further improvement of the present invention, in step S2, the abnormal measurement of the probe motion state is as follows: the probe is moved perpendicular to the surface of the unsupported area of ​​the rock wall and is struck at the same time, so that it is in a state of vibration at different frequencies, so that the probe vibrates when it moves on the uneven rock wall surface.

[0016] Beneficial effects: 1. The method provided by this invention involves selecting rock walls that meet different working conditions and using ground-penetrating radar to test the loosening zone. The ground-penetrating radar probe is manually operated to simulate four different working conditions, and the abnormal feature maps generated under different working conditions are recorded as a reference for distinguishing abnormal maps from normal maps. This method can effectively identify abnormal feature points in the loosening zone map, greatly increasing the applicability of ground-penetrating radar and improving the accuracy of measurement results.

[0017] 2. The method provided by this invention, by comparing the changes in the size of the loosened zone of the surrounding rock before and after applying the abnormal feature map analysis method, clearly shows that the size of the loosened zone is significantly reduced after removing the abnormal feature map. When using the size of the loosened zone as the basis for support design, it can effectively avoid overestimating the range of the loosened zone due to incorrect reading of the loosened zone map features, resulting in problems such as excessively long anchor bolt and anchor cable parameters in the support design. This can reduce enterprise production costs while meeting the requirements of surrounding rock support strength, thus reducing costs and increasing efficiency for mining enterprises.

[0018] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0019] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0020] Figure 1 This is a schematic diagram of the rock wall to be tested in the method for collecting and analyzing the loosening zone anomaly map of mine surrounding rock based on ground-penetrating radar provided by the present invention. The 2m and 3m marked in the figure are the minimum size requirements of the rock wall to be tested. Figure 2 This is a schematic diagram of a simulated working condition one of the methods for collecting and analyzing anomaly maps of loosened rock in mines based on ground-penetrating radar, provided by the present invention. Figure 3This is a schematic diagram of the simulation working condition two of the method for collecting and analyzing the anomaly map of the loosened zone of the surrounding rock in a mine based on ground-penetrating radar provided by the present invention; Figure 4 This is a schematic diagram of the simulation working condition three of the method for collecting and analyzing the anomaly map of the loosened zone of the surrounding rock in a mine based on ground-penetrating radar provided by the present invention; Figure 5 This is a schematic diagram of the simulation working condition four of the method for collecting and analyzing the anomaly map of the loosened zone of the surrounding rock in a mine based on ground-penetrating radar provided by the present invention; Figure 6 yes Figure 2 Anomaly feature map A corresponding to medium working condition 1; Figure 7 yes Figure 3 Anomaly feature map B corresponding to medium working condition 2; Figure 8 yes Figure 4 Anomaly feature map C corresponding to medium working condition 3; Figure 9 yes Figure 5 Anomaly feature map D corresponding to medium working condition four; Figure 10 This is the analysis graph of Example 1. The right side of the graph shows the 0-6m scale lines indicating the size of the loosening zone. Figure 11 This is the analysis graph of Example 2; the right side of the graph shows the 0~4m scale lines indicating the size of the loosening zone; Figure 12 This is the analysis graph of Example 3; the right side of the graph shows the 0-5m scale lines indicating the size of the loosening zone; Figure 13 This is the analysis graph of Example 4; the right side of the graph shows the 0-6m scale lines indicating the size of the loosening zone; Figure 14 This is the analysis graph of Example 5; the right side of the graph shows the 0~5m scale lines indicating the size of the loosening zone.

[0021] Figure Labels 1. Anchor bolt; 2. Rock wall; 21. Smooth area of ​​rock wall without anchor bolt; 22. Rock wall anchor bolt area; 3. Measurement path of probe in working condition one / working condition four; 41. Probe lifting point; 42. Probe striking point; 5. Measurement path of probe in working condition two; 6. Measurement path of probe in working condition three; 7. Ground penetrating radar; 8. Probe. Detailed Implementation

[0022] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0023] Unless otherwise defined, 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; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the invention, are intended to cover non-exclusive inclusion.

[0024] In the description of the embodiments of this invention, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this invention, "multiple" means two or more, unless otherwise explicitly defined.

[0025] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0026] In the description of the embodiments of this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0027] In the description of the embodiments of the present invention, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0028] In the description of the embodiments of the present invention, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0029] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0030] To address the technical problem of inaccurate identification of loosened zone boundaries in mine surrounding rock measurements caused by uneven rock walls and improper human operation, this invention provides a method for acquiring and analyzing anomaly maps of loosened zones in mine surrounding rock based on ground-penetrating radar. The system acquires typical anomaly maps under different working conditions, establishes characteristic criteria, and accurately locates and removes abnormal high-brightness levels in normal loosened zone maps, restoring the true boundaries of the loosened zone and ensuring the accuracy of the measurement results. This invention, through active simulation and pre-calibration of abnormal interference maps, can systematically eliminate the misleading effects of common engineering site factors such as uneven rock walls, metal reflections from anchor bolts, probe angle deviations, and vibrations caused by the smoothness of the rock wall on the detection results. It effectively avoids misjudging abnormal signals such as anchor bolt end reflections as rock fissures or loosening zones, thereby obtaining a more realistic range of rock loosening. It effectively reduces the stringent requirements on the smoothness of the rock wall conditions at the detection site and the technical level of the operators. Even on uneven rock surfaces or in complex environments with metal supports, it can obtain accurate results by eliminating interference through map comparison.

[0031] Please see Figures 1 to 9 As shown, this embodiment of the invention provides a method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, including the following steps: S1. Select the loosened zone test location on rock wall 2, such as... Figure 1 As shown, the test site requires the rock wall 2 to be sufficiently flat, with a slab-like rock wall being optimal. The surface of the rock wall 2 contains at least one row of metal anchor bolts 1, and there are no other metal components besides the metal anchor bolts 1.

[0032] S2. Ground-penetrating radar 7 is used to conduct loosening zone tests on the rock wall 2 at the selected test location. By controlling the position and movement of the probe 8 of the ground-penetrating radar 7, different abnormal geological structure conditions are simulated, mainly including the following four working conditions: (1) such as Figure 2As shown, in working condition one / working condition four, the measuring probe 8 moves slowly along the smooth area 21 of the rock wall without anchor rods. The probe measuring path 3 is perpendicular to the surface of the rock wall 2. Every time it moves a certain distance, when it passes the probe lift-off point 41, the probe 8 is manually lifted to detach it from the rock wall 2. This is working condition one, simulating when the probe 8 is not in contact with the rock wall 2 or when the probe 8 intermittently detaches from the rock wall 2 due to the unevenness of the rock wall 2 surface. (2) For example Figure 3 As shown, the measuring probe 8 moves slowly along the rock wall anchor area 22 in working condition 2. The probe measuring path 5 is perpendicular to the surface of the rock wall 2. The probe 8 is required to pass through at least three anchors 1, which is used as working condition 2 when the probe 8 detects the influence of the anchors 1. (3) such as Figure 4 As shown, the measurement path 6 of the three probes moves at different angles to the surface of the rock wall 2 along the smooth area 21 of the rock wall without anchor rods, which is used as a simulation of the third working condition when the probe 8 is not perpendicular to the rock wall 2. (4) such as Figure 5 As shown, the measuring probe 8 moves rapidly along the smooth area 21 of the rock wall without anchor rods in working condition one / working condition four. The probe measuring path 3 is perpendicular to the surface of the rock wall 2. When passing each probe striking point 42, the probe 8 is struck, so that the probe 8 is vibrating at different frequencies. This is working condition four, which simulates the vibration generated when the probe 8 moves on the uneven surface of the rock wall 2.

[0033] Further analysis of the collected abnormal feature maps, and their corresponding records for the four operating conditions, are as follows: (1) Record the characteristic spectrum generated when the probe is manually lifted at time 8 after each probe lift-off point 41 in working condition 1. Figure 6 It can be seen that when probe 8 passes the probe lift-off point 41, long and continuous bright lines ①~④ will be generated on the spectrum. These long and thin bright lines ①~④ are perpendicular to the bottom edge of the spectrum, cutting through the normal high-brightness color spectrum on both sides. The length of these long and thin bright lines ①~④ is greater than the range of the normal high-brightness color spectrum and inserts into the low-darkness color spectrum, making them significantly distinguishable from the normal spectrum. This spectrum serves as an abnormal characteristic spectrum A when probe 8 is not in contact with the rock wall 2 or when the uneven surface of the rock wall 2 causes probe 8 to intermittently detach from the rock wall 2.

[0034] (2) Record the characteristic map generated when probe 8 moves past anchor bolt 1 in working condition 2. Figure 7It can be seen that when probe 8 passes through anchor 1, it produces elongated, high-brightness color spectrum patterns ①~⑤ with basically flush left and right edges. The colors of the elongated, high-brightness color spectrum patterns ①~⑤ are gradient, extending from the ordinary high-brightness color spectrum and intersecting into the low-darkness color spectrum, and their length is significantly greater than that of the ordinary high-brightness color spectrum. The pattern shape is basically the same as the ordinary spectrum, and the brightness and length of the elongated, high-brightness color spectrum patterns ①~⑤ are different when passing through different anchors 1, making them difficult to distinguish. This spectrum serves as the abnormal feature spectrum B when probe 8 detects the influence of anchor (metal) 1.

[0035] (3) Record the characteristic map generated when the angle of probe 8 was not perpendicular to the rock wall at time 2 during working condition 3. Figure 8 It can be seen that when probe 8 is not moved vertically, it produces a long strip of bright color gradation spectrum ①~④ composed of different flat circular rings. The left and right edges of the spectrum are irregular, and the flat circular rings are discontinuous, leaving certain gaps. When the color gradation extends from the normal bright color gradation spectrum and inserts into the dark color gradation spectrum, it presents a gradual change from light to dark, and its length is significantly greater than the range of the normal bright color gradation spectrum. It is not easy to distinguish it clearly when mixed with the normal spectrum. This spectrum is regarded as the abnormal characteristic spectrum C when probe 8 is not perpendicular to the measured rock wall 2.

[0036] (4) Record the characteristic spectrum generated when manually moving and striking the probe 8 at each probe striking point 42 in working condition 4. Figure 9 It can be seen that when probe 8 passes the probe impact point 42, it will produce a distorted spectrum ①~⑥ composed of thin lines of different lengths arranged left and right. This spectrum has a small characteristic width, the lines are obviously distorted, and the length is greater than the range of normal high-brightness color spectrum, making it easy to distinguish when mixed with the normal spectrum. This spectrum serves as the abnormal characteristic spectrum D when probe 8 moves on the uneven rock wall 2 surface and generates vibration.

[0037] S3. Select the target rock wall 2 to be measured and measure the loosened zone. Use ground-penetrating radar 7 to scan and obtain the measured map.

[0038] S4. Using the abnormal feature maps A, B, C, and D recorded in step S2 as a reference, compare the measured map with the abnormal feature map reference library to identify and remove abnormal feature points in the measured map that correspond to the abnormal feature map.

[0039] S5, Loosening Zone Determination: Based on the measured map after removing abnormal feature points, the range of the loosening zone of the surrounding rock is determined by analysis.

[0040] Preferably, in step S1, the rock wall 2 at the loosening zone test site must be sufficiently smooth, with a length of not less than 3m and a width of not less than 2m. The rock wall 2 must be divisible into an anchor-supported area, i.e., the rock wall anchor area 22, and an unsupported area, i.e., a smooth rock wall area 21 without anchors. The number of anchors 1 in the rock wall anchor area 22 must be not less than 3, and the anchors 1 must be arranged regularly, with the exposed length meeting the measurement requirements of the probe 8 of the ground-penetrating radar 7 when it moves past the anchors 1.

[0041] Preferably, by using the four manual operation methods of moving the probe 8 as described in step S2 (condition 1, condition 2, condition 3, and condition 4), the possible situations that the ground-penetrating radar 7 may encounter when measuring the loosened zone, such as unevenness on the surface of the rock wall 2 or human operation errors, are simulated. This ensures that only a single variable change of the factor that generates the abnormal feature spectrum is performed each time, which can guarantee the correspondence when collecting the abnormal feature spectrum and make the collected abnormal feature spectrum more typical and accurate.

[0042] Preferably, in step S3, the four types of anomaly feature maps A, B, C, and D have broad applicability and can be used as anomaly feature map analysis tools for all applications of ground-penetrating radar 7 in loosening zone measurement.

[0043] Using the above method, the probe 8 of the ground-penetrating radar 7 was operated manually to simulate four different working conditions, and the abnormal feature maps A, B, C, and D generated under different working conditions were recorded. These maps served as a reference for distinguishing between abnormal and normal maps, effectively identifying abnormal feature points in the loosened zone map, greatly increasing the applicability of the ground-penetrating radar 7 and improving the accuracy of the measurement results.

[0044] The feasibility and accuracy of this method are verified below with reference to specific embodiments 1 to 5.

[0045] Example 1 Embodiment 1 of the present invention provides a method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, the specific application of which is as follows: Measurement results of the loosened zone of the surrounding rock in a mine roadway are as follows: Figure 10 As shown, Figure 10The presence of elongated, thin bright lines (marked at ① and ③) and distorted, fluctuating lines (marked at ②) in the image, along with features matching those of anomaly feature maps A and D, indicates abnormal conditions caused by probe 8 not being in contact with the surface of the rock wall 2 and vibrations occurring during probe 8's movement. Following the principle that higher color levels indicate more fragmented surrounding rock, and lower color levels indicate more intact surrounding rock, with the boundary between high and low color levels being the boundary of the loosening zone, the size of the loosening zone was determined as follows: before removing the anomaly feature maps, the size of the loosening zone was determined by the top of the elongated, thin bright line (marked at ③), indicating a loosening zone depth > 8m; after removing areas matching the features of anomaly feature maps A and D, the loosening zone depth ≤ 2.6m. The difference in the size of the loosening zone identified by the two methods is significant.

[0046] Example 2 Embodiment 2 of the present invention provides a method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, and its specific application is as follows: Measurement results of the loosened zone of the surrounding rock in a mine roadway are as follows: Figure 11 As shown, Figure 11 The images show elongated, bright color-scale patterns with roughly flush left and right edges (marked at ①, ②, and ③) and thin, bright lines (marked at ④). These patterns match the characteristics of anomaly pattern B and anomaly pattern A, indicating abnormal conditions where probe 8 passed through metal anchor 1 and probe 8 did not adhere to the surface of the rock wall 2 being tested. Following the principle that higher brightness indicates more fragmented surrounding rock, and lower darkness indicates more intact surrounding rock, with the boundary between high and low brightness levels being the boundary of the loosening zone, the following pattern analysis was performed: Before removing the abnormal pattern, the size of the loosening zone was determined by the top of the thin, bright line (marked at ④) and the elongated, bright color-scale pattern (marked at ②), indicating a loosening zone depth > 4m. After removing patterns matching the characteristics of anomaly pattern A and anomaly pattern B, the loosening zone depth ≤ 2.3m. The difference in the size of the loosening zone identified by the two methods is significant.

[0047] Example 3 Embodiment 3 of the present invention provides a method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, with specific applications as follows: Measurement results of the loosened zone of the surrounding rock in a mine roadway are as follows: Figure 12 As shown, Figure 12The presence of lines exhibiting significant distortion and fluctuation (marked at ① and ②) in the image, along with the characteristic morphology of anomaly feature spectrum D, indicates an abnormal working condition caused by the vibration of probe 8. Following the principle that higher color levels indicate more fragmented surrounding rock, and lower color levels indicate more intact surrounding rock, with the boundary between high and low color levels representing the loosening zone boundary, the image analysis was conducted as follows: Before removing anomaly feature spectrums, the size of the loosening zone was determined by the tip of the thin, bright lines (marked at ① and ②), indicating a loosening zone depth > 4.8m; after removing spectrums matching the characteristic morphology of anomaly feature spectrum D, the loosening zone depth ≤ 3m. The difference in the size of the loosening zone identified by the two methods is significant.

[0048] Example 4 Embodiment 4 of the present invention provides a method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, with specific applications as follows: Measurement results of the loosened zone of the surrounding rock in a mine roadway are as follows: Figure 13 As shown, Figure 13 The image shows elongated, high-brightness color gradations composed of different flat, circular arrays (marked at ①~⑤) and distinct, thin, bright lines (marked at ⑥). These color gradations match the characteristics of anomaly characteristic maps C and A, indicating abnormal conditions where probe 8 was not in contact with the surface of the rock wall 2 and was not moving perpendicularly to the surface. Following the principle that higher brightness indicates more fragmented surrounding rock, and lower darkness indicates more intact surrounding rock, with the boundary between high and low brightness levels being the boundary of the loosened zone, the following color gradation analysis was performed: before removing the abnormal characteristic maps, the size of the loosened zone was determined by the tip of the thin, bright line (marked at ⑥), indicating a depth > 6m; after removing the color gradations matching the characteristics of anomaly characteristic maps A and C, the depth of the loosened zone was ≤ 2.8m. The difference in the size of the loosened zone identified by the two methods is significant.

[0049] Example 5 Embodiment 5 of the present invention provides a method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, with specific applications as follows: Measurement results of the loosened zone of the surrounding rock in a mine roadway are as follows: Figure 14 As shown, Figure 14 No characteristic features matching the anomalous feature maps A-D were found in this map, which is a typical map for measuring the loosening zone. Following the principle that higher color levels indicate more fragmented surrounding rock, and lower color levels indicate more intact surrounding rock, with the boundary between high and low color levels being the boundary of the loosening zone, the map was used for judgment: the loosening zone depth is ≤2.2m. This standard map serves as a comparison map for Examples 1-4.

[0050] Comparing the changes in the size of the loosened zone of the surrounding rock before and after applying the abnormal feature map analysis method provided by this method in Examples 1 to 5, it can be clearly seen that the size of the loosened zone is significantly reduced after removing the abnormal feature map. This effectively avoids overestimating the range of the loosened zone due to incorrect reading of the loosened zone map features, which could lead to problems such as excessively long anchor bolts and anchor cables in the support design. This method ensures the strength requirements of the surrounding rock support while reducing the production costs of enterprises, which is of great significance to mine production.

[0051] In summary, this invention discloses a method for acquiring and analyzing anomaly maps of loosened zones in mine surrounding rock based on ground-penetrating radar (GPR), relating to the field of underground mine rock mechanics technology. The method includes: selecting a test rock wall with a smooth surface and several regularly arranged anchor bolts in some areas, free of other metal components; maneuvering a GPR probe on the test rock wall under four non-ideal states controlled by a single variable: intermittent probe detachment due to uneven rock wall surface, interference from metal anchor bolts, non-vertical angular movement, and vibration caused by the smoothness of the rock wall; acquiring and calibrating four typical anomaly feature maps as a reference library; subsequently, performing routine detection on the test rock wall, comparing the obtained measured maps with the reference library, eliminating anomaly feature points that match the anomaly map characteristics, and delineating the loosened zone range based on the remaining normal features. This invention, by actively constructing a standardized anomaly map library, achieves accurate removal of measurement interference signals, effectively solving the problem of misjudgment of loosened zones due to rock wall conditions or operational deviations, and significantly improving detection accuracy and efficiency.

[0052] It should be noted that the present invention is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments that have the same structure and perform the same effects as the technical concept within the scope of the present invention are included within the scope of the present invention. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of the present invention, are also included within the scope of the present invention.

Claims

1. A method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, characterized in that, Includes the following steps: S1, Test location selection: The rock wall surface at the test location is flat and divided into anchor-supported area and unsupported area; S2, Anomaly Map Calibration: At the selected test location, the measurement state of the ground-penetrating radar probe is manually controlled to simulate various typical abnormal measurement conditions caused by uneven rock walls, metal electromagnetic interference, abnormal probe measurement posture, or probe vibration due to the smoothness of the rock wall during the loosening zone measurement process. Anomaly feature maps under each typical abnormal geological structure measurement condition are collected to establish an anomaly feature map reference library. S3, Loosening Zone Measurement: Ground-penetrating radar scan is performed on the rock wall to be tested to obtain the measured map; S4, Abnormal Feature Comparison and Removal: The measured map is compared with the abnormal feature map reference library to identify and remove abnormal feature points in the measured map that correspond to the abnormal feature map. S5, Loosening Zone Determination: Based on the measured map after removing abnormal feature points, the range of the loosening zone of the surrounding rock is determined by analysis.

2. The method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, as described in claim 1, is characterized in that... In step S2, the various typical abnormal geological structure measurement conditions include: The abnormal coupling state between the probe and the rock wall surface is simulated by controlling the contact / intermittent detachment state between the probe and the rock wall surface. Abnormal electromagnetic interference with metals was simulated by setting metal anchors along the probe's measurement path. The probe's abnormal posture is simulated by changing the spatial angle of the probe relative to the rock wall surface; and The abnormal movement of the probe was simulated by changing the probe's moving speed and applying external vibrations of different frequencies.

3. The method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, as described in claim 2, is characterized in that... In step S2, each simulation measurement changes only one measurement state to simulate a single typical abnormal geological structure measurement condition, while keeping other measurement states at standard measurement conditions, so that a single variable correspondence is formed between each abnormal feature map and the abnormal measurement conditions.

4. The method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar according to claim 1, characterized in that, In step S1, the anchor support area is provided with metal anchors arranged in rows, and there are no other metal components on the rock wall surface except for the metal anchors.

5. The method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar according to claim 4, characterized in that, In step S1, the rock wall is a flat rock wall with a length of not less than 3m and a width of not less than 2m; the number of metal anchors is not less than 3, and they are arranged in a regular manner, and the exposed length of the anchors meets the measurement requirements of the ground-penetrating radar probe when it moves past the anchors.

6. The method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar according to claim 1, characterized in that, In step S4, the measured map is matched with each abnormal feature map in the abnormal feature map reference library one by one. When the similarity between a local feature in the measured map and any abnormal feature map reaches a preset threshold, the local feature is determined to be an abnormal feature and is removed.

7. The method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, as described in claim 2, is characterized in that... In step S2, the measurement of abnormal coupling between the probe and the rock wall surface is achieved by intermittently detaching the probe in the following way: the probe is moved slowly perpendicular to the surface of the unsupported area of ​​the rock wall, and after moving a certain distance, the probe is lifted manually to detach it from the rock wall. This simulates the real working condition where the probe is not attached to the rock wall or the probe is intermittently detached from the rock wall due to the unevenness of the rock wall.

8. The method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, as described in claim 2, is characterized in that... In step S2, the measurement of abnormal metal electromagnetic interference is performed by slowly moving the probe perpendicular to the surface of the rock wall anchor support area, passing through at least three metal anchors during the movement, in order to simulate the working condition when the probe detects the influence of the metal anchors.

9. The method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar, as described in claim 2, is characterized in that... In step S2, the abnormal probe posture measurement is performed by moving the probe at multiple different non-zero angles to the surface of the unsupported rock wall, thereby simulating the working condition when the probe is not perpendicular to the measured rock wall.

10. The method for acquiring and analyzing anomaly maps of loosened rock zones in mines based on ground-penetrating radar according to claim 2, characterized in that, In step S2, the abnormal measurement of the probe's motion state is as follows: the probe is moved perpendicular to the surface of the unsupported area of ​​the rock wall and struck, causing it to vibrate at different frequencies, thus creating a vibration condition when the probe moves on the uneven rock wall surface.

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