Geomembrane defect detection device and method under sand gravel medium coverage condition

Abstract

The invention discloses a geomembrane defect detection device and method under a sand gravel medium coverage condition. The geomembrane defect detection device comprises a signal transmitting assembly, a signal receiving assembly and a signal detection rod, the signal transmitting assembly comprises a plurality of transmitting anodes, a plurality of transmitting cathodes and a signal transmitting module; the signal transmitting module comprises a high-power rectifying and filtering module, a buck-boost module, a transmitting display module and a transmitting control module; the signal receiving assembly comprises a gain module, a filtering module, an acquisition module, a sensitivity module, a receiving control module, a storage module, a GPS module and a receiving display module. And four pairs of steel chisels are arranged on the signal detection rod and are connected with the receiving and collecting module. Four voltage distribution diagrams can be obtained through the signal transmitting assembly, the signal receiving assembly and the signal detection rod, efficient and rapid detection of geomembrane defects can be achieved, meanwhile, judgment of geomembrane defect positions and suspected geomembrane defect positions is more accurate, and the misjudgment risk of the geomembrane defect positions is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of geomembrane defect detection, and in particular to a device and method for detecting geomembrane defects under a condition of sand and gravel medium coverage. Background Art

[0002] Geomembrane is an emerging anti-seepage material with high molecular polymer as basic raw material. It has the advantages of strong deformation ability, good anti-seepage performance and low economic cost. It is widely used as an anti-seepage material for hydraulic structures such as reservoirs, reservoirs and channels.

[0003] After geomembrane installation, it needs to be covered with a layer of compacted sand, gravel, or other soil and rock materials as a protective layer. During the compaction process using heavy machinery, the underlying covering material can easily damage the geomembrane, compromising its waterproofing effectiveness. Defect detection for geomembranes under covered conditions typically utilizes a two-electrode method. This method involves applying an electric field to the geomembrane and using mobile detection equipment to locate the defect holes based on the distribution of the electric potential within the protective layer. During testing, a power supply electrode is placed in each of the upper and lower layers of the geomembrane, connected to the positive and negative terminals of a high-voltage DC power supply. Generally, when the geomembrane is intact, no circuit can be formed between the power supply electrodes. However, when a hole in the geomembrane exists, the hole creates a path, generating current in the circuit. The hole acts as a current source, resulting in a noticeable anomaly in the electric potential near the hole. Therefore, the hole can be located by detecting the anomaly in the electric potential field on the membrane using a mobile detection device. The aforementioned geomembrane defect detection device and method can only generate a voltage distribution map, which is ineffective in distinguishing the location of geomembrane defects and suspected geomembrane defects, and has a high risk of misjudgment. Therefore, to address the above issues, it is necessary to propose a more efficient geomembrane defect detection device and method under gravel medium coverage conditions. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a device and method for detecting defects in geomembranes under conditions of sand and gravel medium coverage.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is: Provided are a device and method for detecting defects in geomembranes under conditions of sand and gravel medium coverage, comprising a signal transmitting component, a signal receiving component and a signal detection rod, wherein the signal receiving component is electrically connected to the signal detection rod; the signal transmitting component comprises a plurality of transmitting positive electrodes arranged on the upper surface of the geomembrane, a plurality of transmitting negative electrodes arranged on the lower surface of the geomembrane and a signal transmitting module, wherein the transmitting positive electrodes and the transmitting negative electrodes are electrically connected to the signal transmitting module, and the signal transmitting module comprises a high-power rectifier and filter module, a buck-boost module, a transmitting display module and a transmitting control module, wherein the high-power rectifier and filter module are electrically connected to the buck-boost module, and the buck-boost module, the transmitting display module and the transmitting control module The signal detection rod is electrically connected to the signal acquisition module; the signal receiving component includes a gain module, a filter module, an acquisition module, a sensitivity module, a receiving control module, a storage module, a GPS module and a receiving display module. The gain module is electrically connected to the filter module, the filter module is electrically connected to the acquisition module, the acquisition module is electrically connected to the sensitivity module, the sensitivity module is electrically connected to the receiving control module, the gain module is electrically connected to the filter module, the filter module is electrically connected to the acquisition module, the storage module, the GPS module, the receiving display module and the receiving control module are electrically connected; four pairs of steel drills are provided on the signal detection rod, and each steel drill is connected to the receiving acquisition module through a detection line.

[0006] Furthermore, the signal detection rod includes a vertical telescopic rod, and a handheld short rod is fixed on the top of the vertical telescopic rod; the bottom of the vertical telescopic rod is fixedly connected to a mounting rod, and several groups of rotating sleeves are provided on the mounting rod, and the rotating sleeves can rotate in the horizontal direction, and horizontal telescopic rods are symmetrically fixed on both sides of each rotating sleeve; a steel drill clamp is fixed at the far end of each horizontal telescopic rod, and each steel drill clamp is provided with a vertical through hole for fixing the steel drill, and insulation treatment is used between the vertical through hole and the steel drill.

[0007] Furthermore, a plurality of C-shaped steel bar clips are fixed to the outermost telescopic tube of the vertical telescopic rod, and the number of the steel bar clips matches the number of the steel bars.

[0008] Furthermore, the clamping axis direction of the steel drill clip is parallel to the horizontal plane.

[0009] Furthermore, the clamping opening of the steel drill clip is an arc opening, and the inner diameter of the arc opening is excessively matched with the steel drill.

[0010] Furthermore, the rotating sleeves are provided at four locations, and the rotating sleeves at the four locations are evenly distributed on the mounting rod.

[0011] A method for detecting defects of a geomembrane under a sand and gravel medium covering condition comprises the following steps: S1. When laying the geomembrane, bury N transmitting negative electrodes on the lower surface of the geomembrane. The N transmitting negative electrodes are arranged in parallel and at equal distances. Bury N transmitting positive electrodes on the upper surface of the geomembrane. The transmitting negative electrodes correspond to the transmitting positive electrodes. Connect the N transmitting negative electrodes and the N transmitting positive electrodes to the transmitting control module. S2. Determine M detection points above each N-emitting positive electrode to confirm the geomembrane defect detection location; S3, after selecting the appropriate voltage and current through the transmission control module of the signal transmitter, the electrical signal is transmitted using the transmission cathode and the transmission anode; S4. Move the signal detection rod to the detection position in sequence, cooperate with the signal receiving component to receive the signal transmitted by the signal transmitting device, and collect the schematic voltage values ​​of several detection points; S5. At each detection point of the signal detection rod, the schematic voltage value of the detection point in four directions can be obtained. The schematic voltage value in the same direction of each detection point is used to make a voltage distribution diagram to obtain four voltage distribution diagrams in four directions; S6. Determine the geomembrane defect location and the suspected geomembrane defect location through the four voltage distribution diagrams, and further determine the geomembrane defect location, specifically: S61. When the positive sign of the positive electrode of the transmitter at a certain location or the positive electrode of the interval transmitter shows an abnormal change, the corresponding detection point on the voltage distribution diagram is the location of the geomembrane defect; when the positive sign of the positive electrode of the transmitter at a certain location shows an abnormal change, or the positive sign of the transmitter at a certain direction shows an abnormal change, or the positive electrode of the transmitter at a certain location shows a difference of 10 times that of the surrounding signal, it is determined to be a suspected geomembrane defect location, and the next step is performed; S62, determining the positive electrode positions of the emission source corresponding to the suspected defect positions of the geomembrane, and further determining the suspected defect positions of the geomembrane; S63, move the signal detection rod to a 3m×3m range around the suspected defect location of the geomembrane, repeat steps S3-S5, obtain a new voltage distribution map, and re-determine the suspected defect location of the geomembrane using the judgment method of step S61. If it is again determined that a geomembrane defect location exists, then a geomembrane defect actually exists at the suspected defect location of the geomembrane; if it is again determined that a suspected defect location exists, then no geomembrane defect exists at the suspected defect location of the geomembrane; S64. According to the determined location of the geomembrane defect, find the location of the geomembrane defect, excavate the covering layer, and repair the geomembrane defect.

[0012] Furthermore, the emission control module is installed in the electric field release device, and the electric field release device provides power to N emission positive poles and N emission negative poles. The position of the electric field release device is determined by: A1: Use 3D point cloud scanning equipment to scan the inspection area, construct a 3D topographic map of the inspection area, and establish a 3D coordinate system within the topographic map; A2: Grid the surface of the 3D terrain map and obtain the coordinates of each grid center in the 3D coordinate system. , nis the grid number, according to the area of ​​the detection area S As well as the rated voltage of the electric field release device, plan the number of power points in the detection area M ; ; in, Rated voltage released by the electric field release device, The minimum voltage that the voltage detection terminal can detect. d is the electric field diffusion radius, is the average attenuation rate of voltage with distance in the detection area; A3: Based on the vertical coordinates of each grid Size, filter out M grid high points within the detection area, M The vertical coordinate value corresponding to the grid high point is the first one in the descending order of the grid vertical coordinate values. M The center coordinates of the grid high point are used as the reference high point coordinates. , m is the number of the reference high point; A4: Take the discrete distribution evenly on the terrain surface of the three-dimensional terrain map M power reference points and obtain the coordinates of each power reference point , u Number the power reference point and filter the two closest reference high points and the power reference point. The filtering constraints are: ; in, are the collection of reference high point and power reference point respectively, The maximum voltage that the electric field release device can release; A5: If the power reference point u There is a reference high point around m If the constraint condition is met, the reference high point m As the best power source in the nearby area, if the power reference point u There is no reference high point around m If the constraints are met, the power reference point u As the best power source in the surrounding area; A6: After all the optimal power supply points in the detection area are determined, the electric field release device, the negative emission electrode and the positive emission electrode are installed on the optimal power supply points according to the positions of the coordinates corresponding to the optimal power supply points in the detection area.

[0013] The beneficial effects of the present invention are: The present invention can obtain four voltage distribution diagrams through the signal transmitting component, the signal receiving component and the signal detection rod. Combined with the unique geomembrane defect detection method, it can achieve efficient and rapid detection of geomembrane defects. At the same time, the judgment of the geomembrane defect position and the suspected geomembrane defect position is more accurate, reducing the risk of misjudgment of the geomembrane defect position.

[0014] The signal detection rod of the present invention includes a vertical telescopic rod and several horizontal telescopic rods that can be telescopically stored, thereby reducing the volume of the multi-directional detection rod. At the same time, the steel rod buckle is used to store and fix the several steel rods, so that the volume of the multi-directional detection rod is further reduced, making it convenient to carry and use the multi-directional detection rod.

[0015] The signal detection rod of the present invention includes four groups of retractable steel drills, and the two steel drills in each group form a group of receiving electrodes M and receiving electrodes N. The four groups of receiving electrodes M and receiving electrodes N can realize electrical signal detection in four directions at the detection position.

[0016] The signal detection rod of the present invention can realize the detection of geomembrane defects under cover weight conditions. The grounding electrode of the traditional DC resistance method dipole device has been modified to realize the free movement of the electrode, thereby realizing the detection of geomembrane defects (≥5mm) under cover weight (600mm).

[0017] The signal detection rod of the present invention eliminates the work of laying out wires, inserting electrodes, changing electrodes, etc., greatly improving the detection efficiency. At the same time, compared with the traditional DC resistivity detection device, one person can complete all the detection work, with low labor intensity, greatly improving the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the structure of the signal transmission component in the present invention; Figure 2 Schematic diagram of the structure of the signal receiving component in the present invention; Figure 3 Schematic diagram of the structure of the signal detection rod in the present invention.

[0019] The main components in the figure are described as follows: 1. Hand-held short rod; 2. T-shaped tee; 3. Vertical telescopic rod; 4. Steel drill clip; 5. Multi-directional connecting shaft; 6. Horizontal telescopic rod; 7. Steel drill fixture; 8. Steel drill. DETAILED DESCRIPTION

[0020] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0021] like Figure 1 As shown, the geomembrane defect detection device under the condition of sand and gravel medium coverage includes a signal transmitting component, a signal receiving component and a signal detection rod, and the signal receiving component is electrically connected to the signal detection rod.

[0022] The signal transmitter assembly includes several positive transmitting electrodes mounted on the upper surface of the geomembrane, several negative transmitting electrodes mounted on the lower surface of the geomembrane, and a signal transmitter module. Both the positive transmitting electrodes and the negative transmitting electrodes are electrically connected to the signal transmitter module, which includes a high-power rectifier and filter module, a buck-boost module, a transmitter display module, and a transmitter control module. The high-power rectifier and filter module are electrically connected to the buck-boost module, while the buck-boost module and the transmitter display module are electrically connected to the transmitter control module. 220V AC power enters the signal transmitter assembly through the "input" terminal, passes through the high-power rectifier and filter module, converts it to DC power, and then passes through the buck-boost module to the required voltage. To obtain reliable detection data even under poor grounding conditions, the maximum voltage of the transmitter is increased to 1000V. The signal is then transmitted through the "output" terminal using two electrodes. The transmitter control module obtains the output voltage and current in real time, adjusts the output value in real time, and stabilizes it at the set value, which is displayed on the transmitter display module. The emission control module monitors the input and output voltage, current and temperature at the same time, and can also be set up with an abnormality monitoring module to issue an alarm when an abnormality occurs.

[0023] like Figure 2As shown, the signal receiving assembly includes a gain module, a filter module, an acquisition module, a sensitivity module, a receiving control module, a storage module, a GPS module, and a receiving display module. The gain module is electrically connected to the filter module, which is electrically connected to the acquisition module, which is electrically connected to the sensitivity module, which is electrically connected to the receiving control module. The gain module is electrically connected to the filter module, which is electrically connected to the acquisition module. The storage module, GPS module, and receiving display module are also electrically connected to the receiving control module. External signals enter the signal receiving assembly through the "acquisition" end. After passing through the gain module and the filter module, the acquisition module converts the analog signal into a digital signal. The receiving control module reads the digital signal, performs conversion calculations, and calculates the actual signal magnitude. To adapt to poor grounding conditions and more sensitively obtain relative changes in measured data, a sensitivity module is added, increasing the sensitivity of the received signal by up to 20 times. Simultaneously, the GPS module is used to obtain positioning data. The receiving display module displays the signal magnitude and positioning data on the screen in real time at the "display" end, and the data is stored in the storage module when needed.

[0024] like Figure 3As shown, the signal detection rod is provided with four pairs of steel drills 8, each of which is connected to the receiving and collecting module via a detection line. The multi-directional detection rod includes a vertical telescopic rod 3, a handheld short rod 1 is fixed to the top of the vertical telescopic rod 3, a T-shaped tee 2 is provided on the top of the vertical telescopic rod 3 for mounting the handheld short rod 1, the bottom of the T-shaped tee 2 is fixed to the vertical telescopic rod 3, and the handheld short rod 1 is nested in the top of the T-shaped tee 2. The handheld short rod 1 facilitates the movement of the multi-directional detection rod and facilitates the detection of geomembrane defects. The bottom of the vertical telescopic rod 3 is fixedly connected to the mounting rod, and the mounting rod is provided with four sets of rotating sleeves. The rotating sleeves are evenly distributed on the mounting rod, and each rotating sleeve can rotate in the horizontal direction. Horizontal telescopic rods 6 are symmetrically fixed on both sides of each rotating sleeve. A steel drill fixture 7 is fixed to the far end of each horizontal telescopic rod 6. The steel drill fixture 7 is preferably made of insulating plastic material. Each steel drill fixture 7 is provided with a vertical through hole. A steel drill 8 is fixed in each vertical through hole. The vertical through hole and the steel drill 8 are insulated. Each steel drill 8 is connected to a detection line. Two steel drills 8 are installed on each of the two horizontal telescopic rods 6 on the rotating sleeve. The two steel drills 8 form a group of receiving electrodes M and receiving electrodes N to achieve electrical signal detection in one direction. Eight steel drills 8 form four groups of steel drills 8 to achieve electrical signal detection in four directions. A rubber ring is fixed in the vertical through hole. The inner diameter of the rubber ring is an interference fit with the outer diameter of the steel drill. The friction between the rubber ring and the steel drill can tighten the steel drill without affecting the steel drill being driven into the soil. The outermost telescopic cylinder of the vertical telescopic rod 3 is fixed with a number of C-shaped steel drill clips 4. The number of steel drill clips 4 matches the number of steel drills 8. The clamping axis direction of the steel drill clips 4 is parallel to the horizontal plane. The clamping opening of the steel drill clips 4 is an arc opening. The inner diameter of the arc opening is excessively matched with the steel drill 8. The steel drill clips 4 are preferably provided with eight locations. The eight steel drills 8 can be fixed in parallel in the eight steel drill clips 4, thereby facilitating the storage of the steel drills 8. The steel drills 8 are fixed with C-shaped steel drill clips 4, which greatly facilitates the fixing and use of the steel drills 8. The telescopic large end of the vertical telescopic rod 3 is fixedly connected to the mounting rod, and the telescopic small end of the vertical telescopic rod 3 is fixedly connected to the handheld short rod 1. The top of the steel drill 8 is provided with a cone portion, which facilitates the insertion of the steel drill 8 into the soil. The top of the steel drill 8 is provided with a disc portion, which can expand the contact area with the hammer, thereby better cooperating with the hammering operation. Steps for changing the signal detection rod from storage mode to use mode: remove the steel drill 8 from the steel drill buckle 4, extend and lock the four horizontal telescopic rods 6 as needed, and rotate the different horizontal telescopic rods 6 to the required direction through the multi-directional connecting shaft 5 and lock them, fix the eight steel drills 8 to the horizontal telescopic rods 6 through the steel drill clamp 7, extend and lock the vertical telescopic rod 3 as needed, and then it is in use mode.Steps for changing the signal detection rod from use mode to storage mode: loosen the steel drill clamp 7, remove all 8 steel drills 8 from the horizontal telescopic rod 6, loosen the multi-directional connecting shaft 5, rotate the 4 horizontal telescopic rods 6 to the same direction as the handheld short rod 1 and lock them, compress all the vertical telescopic rods 3, and fix the 8 steel drills 8 to the vertical telescopic rod 3 in sequence through the steel drill buckles 4, which is the storage mode.

[0025] A method for detecting defects of a geomembrane under a sand and gravel medium covering condition comprises the following steps: S1. When laying the geomembrane, bury N transmitting negative electrodes on the lower surface of the geomembrane. The N transmitting negative electrodes are arranged in parallel and at equal distances. Bury N transmitting positive electrodes on the upper surface of the geomembrane. The transmitting negative electrodes correspond to the transmitting positive electrodes. Connect the N transmitting negative electrodes and the N transmitting positive electrodes to the transmitting control module. S2. Determine M detection points above each N-emitting positive electrode to confirm the geomembrane defect detection location; S3, after selecting the appropriate voltage and current through the transmission control module of the signal transmitter, the electrical signal is transmitted using the transmission cathode and the transmission anode; S4. Move the signal detection rod to the detection position in sequence, cooperate with the signal receiving component to receive the signal transmitted by the signal transmitting device, and collect the schematic voltage values ​​of several detection points; S5. At each detection point of the signal detection rod, the schematic voltage value of the detection point in four directions can be obtained. The schematic voltage value in the same direction of each detection point is used to make a voltage distribution diagram to obtain four voltage distribution diagrams in four directions; S6. Determine the geomembrane defect location and the suspected geomembrane defect location through the four voltage distribution diagrams, and further determine the geomembrane defect location, specifically: S61. When the positive sign of the positive electrode of the transmitter at a certain location or the positive electrode of the interval transmitter shows an abnormal change, the corresponding detection point on the voltage distribution diagram is the location of the geomembrane defect; when the positive sign of the positive electrode of the transmitter at a certain location shows an abnormal change, or the positive sign of the transmitter at a certain direction shows an abnormal change, or the positive electrode of the transmitter at a certain location shows a difference of 10 times that of the surrounding signal, it is determined to be a suspected geomembrane defect location, and the next step is performed; S62, determining the positive electrode positions of the emission source corresponding to the suspected defect positions of the geomembrane, and further determining the suspected defect positions of the geomembrane; S63, move the signal detection rod to a 3m×3m range around the suspected defect location of the geomembrane, repeat steps S3-S5, obtain a new voltage distribution map, and re-determine the suspected defect location of the geomembrane using the judgment method of step S61. If it is again determined that a geomembrane defect location exists, then a geomembrane defect actually exists at the suspected defect location of the geomembrane; if it is again determined that a suspected defect location exists, then no geomembrane defect exists at the suspected defect location of the geomembrane; S64. According to the determined location of the geomembrane defect, find the location of the geomembrane defect, excavate the covering layer, and repair the geomembrane defect.

[0026] Furthermore, the emission control module is installed in the electric field release device, and the electric field release device provides power to N emission positive poles and N emission negative poles. The position of the electric field release device is determined by: A1: Use 3D point cloud scanning equipment to scan the inspection area, build a 3D topographic map of the inspection area, and establish a 3D coordinate system within the topographic map; A2: Grid the surface of the 3D terrain map and obtain the coordinates of each grid center in the 3D coordinate system. , n is the grid number, according to the area of ​​the detection area S As well as the rated voltage of the electric field release device, plan the number of power points in the detection area M ; ; in, Rated voltage released by the electric field release device, The minimum voltage that the voltage detection terminal can detect. d is the electric field diffusion radius, is the average attenuation rate of voltage with distance in the detection area; A3: Based on the vertical coordinates of each grid Size, filter out M grid high points within the detection area, M The vertical coordinate value corresponding to the grid high point is the first one in the descending order of the grid vertical coordinate values. M The center coordinates of the grid high point are used as the reference high point coordinates. , m is the number of the reference high point; A4: Take the discrete distribution evenly on the terrain surface of the three-dimensional terrain map M power reference points and obtain the coordinates of each power reference point , u Number the power reference point and filter the two closest reference high points and the power reference point. The filtering constraints are: ; in, are the collection of reference high point and power reference point respectively, The maximum voltage that the electric field release device can release; A5: If the power reference point u There is a reference high point around mIf the constraint condition is met, the reference high point m As the best power source in the nearby area, if the power reference point u There is no reference high point around m If the constraints are met, the power reference point u As the best power source in the surrounding area; A6: After all the optimal power supply points in the detection area are determined, the electric field release device, the negative emission electrode and the positive emission electrode are installed on the optimal power supply points according to the positions of the coordinates corresponding to the optimal power supply points in the detection area.

Claims

1. A device for detecting defects in geomembranes under conditions of gravel medium coverage, characterized in that: It includes a signal transmitting component, a signal receiving component and a signal detecting rod, wherein the signal receiving component is electrically connected to the signal detecting rod; The signal transmitting assembly includes a plurality of transmitting positive electrodes arranged on the upper surface of the geomembrane, a plurality of transmitting negative electrodes arranged on the lower surface of the geomembrane, and a signal transmitting module. The transmitting positive electrodes and transmitting negative electrodes are electrically connected to the signal transmitting module. The signal transmitting module includes a high-power rectifier and filter module, a buck-boost module, a transmitting display module, and a transmitting control module. The high-power rectifier and filter module is electrically connected to the buck-boost module, and the buck-boost module, the transmitting display module, and the transmitting control module are electrically connected. The signal receiving component includes a gain module, a filter module, an acquisition module, a sensitivity module, a receiving control module, a storage module, a GPS module and a receiving display module, wherein the gain module is electrically connected to the filter module, the filter module is electrically connected to the acquisition module, the acquisition module is electrically connected to the sensitivity module, the sensitivity module is electrically connected to the receiving control module, the gain module is electrically connected to the filter module, the filter module is electrically connected to the acquisition module, and the storage module, the GPS module, the receiving display module and the receiving control module are electrically connected; Four pairs of steel chisels (8) are provided on the signal detection rod, and each pair of steel chisels (8) is connected to a receiving and collecting module via a detection line.

2. The device for detecting defects of geomembranes under the condition of sand and gravel medium coverage according to claim 1 is characterized in that: The signal detection rod comprises a vertical telescopic rod (3), a handheld short rod (1) is fixed to the top of the vertical telescopic rod (3); a mounting rod is fixedly connected to the bottom of the vertical telescopic rod (3), and a plurality of rotating sleeves are provided on the mounting rod, and the rotating sleeves can rotate in the horizontal direction, and horizontal telescopic rods (6) are symmetrically fixed on both sides of each rotating sleeve; a steel drill clamp (7) is fixed to the far end of each horizontal telescopic rod (6), and a vertical through hole for fixing a steel drill (8) is provided on each steel drill clamp (7), and insulation treatment is adopted between the vertical through hole and the steel drill (8).

3. The device for detecting defects of geomembranes under the condition of sand and gravel medium coverage according to claim 2 is characterized in that: A plurality of C-shaped steel drill clips (4) are fixed to the outermost telescopic cylinder of the vertical telescopic rod (3), and the number of the steel drill clips (4) matches the number of the steel drills (8).

4. The device for detecting defects of geomembranes under the condition of sand and gravel medium coverage according to claim 3 is characterized in that: The clamping axis direction of the steel drill clip (4) is parallel to the horizontal plane.

5. The device for detecting defects of geomembranes under the condition of sand and gravel medium coverage according to claim 3 is characterized in that: The clamping opening of the steel drill clip (4) is a circular arc opening, and the inner diameter of the circular arc opening is excessively matched with the steel drill (8).

6. The device for detecting defects of geomembranes under the condition of sand and gravel medium coverage according to claim 2 is characterized in that: The rotating sleeves are arranged at four locations, and the rotating sleeves are evenly distributed on the mounting rod.

7. A method for detecting defects in geomembranes using the device for detecting defects in geomembranes under gravel medium coverage conditions according to any one of claims 1 to 6, characterized in that: The steps include: S1. When laying the geomembrane, bury N transmitting negative electrodes on the lower surface of the geomembrane. The N transmitting negative electrodes are arranged in parallel and at equal distances. Bury N transmitting positive electrodes on the upper surface of the geomembrane. The transmitting negative electrodes correspond to the transmitting positive electrodes. Connect the N transmitting negative electrodes and the N transmitting positive electrodes to the transmitting control module. S2. Determine M detection points above each N-emitting positive electrode to confirm the geomembrane defect detection location; S3, after selecting the appropriate voltage and current through the transmission control module of the signal transmitter, the electrical signal is transmitted using the transmission cathode and the transmission anode; S4. Move the signal detection rod to the detection position in sequence, cooperate with the signal receiving component to receive the signal transmitted by the signal transmitting device, and collect the schematic voltage values ​​of several detection points; S5. At each detection point of the signal detection rod, the schematic voltage value of the detection point in four directions can be obtained. The schematic voltage value in the same direction of each detection point is used to make a voltage distribution diagram to obtain four voltage distribution diagrams in four directions; S6. Determine the geomembrane defect location and the suspected geomembrane defect location through the four voltage distribution diagrams, and further determine the geomembrane defect location, specifically: S61. When the positive and negative signs of the positive electrode of the emission source at a certain position or the positive electrode of the interval emission source show abnormal changes, the corresponding detection point position on the voltage distribution diagram is the geomembrane defect position; When the positive and negative signs of the positive pole of the emission source at a certain location are abnormal, or the positive and negative signs of the emission source at a certain direction are abnormal, or the positive pole of the emission source at a certain location has a difference of 10 times that of the surrounding signals, it is determined to be a suspected defect location of the geomembrane, and the next step is carried out; S62, determining the positive electrode positions of the emission source corresponding to the suspected defect positions of the geomembrane, and further determining the suspected defect positions of the geomembrane; S63, move the signal detection rod to a 3m×3m range around the suspected defect location of the geomembrane, repeat steps S3-S5, obtain a new voltage distribution map, and re-determine the suspected defect location of the geomembrane using the judgment method of step S61. If it is again determined that a geomembrane defect location exists, then a geomembrane defect actually exists at the suspected defect location of the geomembrane; if it is again determined that a suspected defect location exists, then no geomembrane defect exists at the suspected defect location of the geomembrane; S64. According to the determined location of the geomembrane defect, find the location of the geomembrane defect, excavate the covering layer, and repair the geomembrane defect.

8. The method for detecting defects of a geomembrane under gravel medium coverage according to claim 7, characterized in that: The emission control module is installed in the electric field release device, and the electric field release device provides power to N emission positive poles and N emission negative poles. The position of the electric field release device is determined by: A1: Use 3D point cloud scanning equipment to scan the inspection area, construct a 3D topographic map of the inspection area, and establish a 3D coordinate system within the topographic map; A2: Grid the surface of the 3D terrain map and obtain the coordinates of each grid center in the 3D coordinate system. , n is the grid number, according to the area of ​​the detection area S As well as the rated voltage of the electric field release device, plan the number of power supply points in the detection area M ; ； in, Rated voltage released by the electric field release device, The minimum voltage that the voltage detection terminal can detect. d is the electric field diffusion radius, is the average attenuation rate of voltage with distance in the detection area; A3: Based on the vertical coordinates of each grid Size, filter out M grid high points within the detection area, M The vertical coordinate value corresponding to the grid high point is the first one in the descending order of the grid vertical coordinate values. M The center coordinates of the grid high point are used as the reference high point coordinates. , m is the number of the reference high point; A4: Take discrete distributions evenly on the terrain surface of the three-dimensional terrain map M power reference points and obtain the coordinates of each power reference point , u Number the power reference point and filter the two closest reference high points and the power reference point. The filtering constraints are: ； in, are the collection of reference high point and power reference point respectively, The maximum voltage that the electric field release device can release; A5: If the power reference point u There is a reference high point around m If the constraint condition is met, the reference high point m As the best power source in the nearby area, if the power reference point u There is no reference high point around m If the constraints are met, the power reference point u As the best power source in the surrounding area; A6: After all the optimal power supply points in the detection area are determined, the electric field release device, the negative emission electrode and the positive emission electrode are installed on the optimal power supply points according to the positions of the coordinates corresponding to the optimal power supply points in the detection area.

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