A sensitive voltage ranging device for drilling cracks and its use method

Abstract

The present invention discloses a sensitive voltage ranging device for drilling cracks and a method for using the device, which belongs to the field of underground engineering technology. It includes a main rod body and a sensitive transformer. The main rod body is a hollow porous tubular structure. The outside of the main rod body is wrapped with an insulating shell. The end of the main rod body is provided with a discharge structure and multiple high-voltage nozzles. It is also provided with a movable annular sensitive voltage ranging device. After the slurry is fully sprayed into the cracks in the anchor hole, the electrode sheet is used to inject current into the slurry. The annular sensitive voltage ranging device detects the voltage generated from the inner surface of the crack to the device. The greater the voltage generated, the farther the distance. The voltage data of different sections are converted into position data by a data processor. Finally, the position data is used to perform crack imaging calculation, thereby detecting the size and distribution of the anchor hole cracks. The structure of the invention can detect the development and direction of the cracks, and has the advantages of accurate detection, reasonable structure, stable function, and economical applicability.

Description

Technical Field

[0001] The invention relates to a sensitive voltage distance measuring device for a borehole fissure and a use method thereof, belonging to the technical field of underground engineering. Background Art

[0002] During tunnel excavation and mine mining, cracks within anchor holes can lead to instability of the anchor points, compromising the safety of the entire structure. By detecting cracks within anchor holes, potential safety hazards can be identified early, allowing appropriate repair or reinforcement measures to ensure structural safety. Cracks within anchor holes can lead to stress concentration and reduced load-bearing capacity. By examining the morphology, size, and distribution of cracks, the strength and stability of the anchor system can be assessed. This is crucial for selecting the appropriate anchoring solution, determining load-bearing capacity, and predicting the lifespan and reliability of the structure. When cracks appear within anchor holes, prompt maintenance and repair are necessary. By detecting crack conditions, repair methods and materials can be determined to extend the lifespan of the anchor system.

[0003] Currently, commonly used methods for detecting surrounding rock fractures include visual observation, ultrasonic testing, core drilling, and rock mechanics testing. Visual observation is simple and easy, requiring no special equipment, and allows direct observation of fracture morphology and distribution. However, due to limitations in human visual resolution and subjective factors, it cannot accurately measure fracture size and depth, limiting its applicability. Ultrasonic testing is a non-contact method that can quickly measure fracture depth and extension in rock and is applicable to various rock types. However, due to factors such as the rock's acoustic wave propagation characteristics, background noise, and instrument accuracy, errors may occur, requiring specialized equipment and operating techniques. Core drilling and rock mechanics testing are widely used in actual engineering projects. Core drilling can obtain actual fracture samples in the rock for detailed fracture observation and testing. However, this requires core drilling, which places certain demands on rock integrity and is time-consuming and costly. It only captures fracture information at the drill hole location and cannot fully reflect the fracture distribution of the entire surrounding rock. Rock mechanics testing simulates actual engineering conditions by loading specimens to measure the strength and deformation properties of the rock. This can indirectly assess the fracture condition in the surrounding rock. However, this method requires high-level laboratory equipment and technical expertise, and cannot directly measure the size and distribution of cracks. Given these challenges, there is an urgent need to develop a detection device that can accurately detect the aperture, development, and orientation of surrounding rock cracks to address these engineering challenges. This device could accurately detect the presence, aperture, and orientation of cracks and assess their impact on the project, enabling appropriate preventive measures or design adjustments. Summary of the Invention

[0004] Technical problem: In response to the shortcomings of existing technologies, a sensitive voltage ranging device for borehole cracks and a method for using the same are provided. The device has a simple structure and is easy to use. It can accurately detect the opening, development and direction of surrounding rock cracks, and thus guide the selection of suitable underground support and reinforcement technologies to ensure the sustainable and safe operation of the project.

[0005] Technical Solution: To achieve the above technical objectives, the present invention is a sensitive voltage ranging device for drilling fissures, comprising a main rod body and a sensitive transformer. The main rod body is a hollow, porous tubular structure, the outside of which is wrapped with an insulating shell. The end of the main rod body is provided with a discharge structure and multiple high-pressure nozzles. The area of ​​the main rod body other than the discharge structure and the multiple high-pressure nozzles is sheathed with an insulating main sleeve. The main sleeve is provided with a movable annular sensitive voltage ranging device. The tail section of the main sleeve is provided with a threaded section on the outside, through which a tray and an anti-slip wire nut are connected.

[0006] Four axially arranged grouting slots are evenly distributed along the circumference of the main rod body. Each grouting slot is provided with a grouting pipe, which is connected to the grouting vessel through a piston switch. The end of each grouting pipe is connected to a high-pressure nozzle. The high-pressure nozzle is located near the end of the main rod body. A composite slurry containing electrolyte ions is injected into the high-pressure nozzle through the grouting pipe.

[0007] The discharge structure includes two symmetrically arranged electrode wire slots extending from the end of the main rod body and bending back to form a C shape. Each electrode wire slot has an electrode hole and an electrode sheet at the end. Two electrode wire slots connected to the electrode holes are provided in the main rod body. The two electrode sheets are respectively connected to the ends of two electrode wires provided through the electrode holes and the electrode wire slots. The tail ends of the two electrode wires are connected to a sensitive transformer. The electrode sheets are used to inject current into the composite slurry containing electrolyte ions ejected from the high-pressure nozzle.

[0008] A pore pressure sensing device is provided in the middle of the end of the main rod body through a retractable micro spring to detect the pore pressure inside the pore after grouting;

[0009] Two tooth grooves are provided on the surface of the main sleeve, and an annular sensitive voltage ranging device that can move along the main sleeve is connected to the two tooth grooves through gears. The gears are driven by the motor arranged on the main rod body to drive the annular sensitive voltage ranging device.

[0010] Furthermore, the electrolyte ions in the composite slurry have a conductive effect. After the composite slurry is injected into the borehole, the discharge structure is used to discharge electricity, so that current is generated in the composite slurry. The annular sensitive voltage ranging device detects the distance from the inner surface of the crack in the surrounding rock to the main rod body based on the voltage signal detected from the composite slurry and the principle that the farther the distance, the greater the voltage under constant current, thereby realizing crack detection.

[0011] Furthermore, an annular fiber mesh is provided on the high-pressure nozzle, so that the high-pressure slurry sprayed from the high-pressure nozzle can only be sprayed along the circumference and radial directions. The main sleeve is provided with an annular slurry stopper on the outer cover of the crack detection area to prevent the injected composite slurry from seeping into the main rod body.

[0012] Furthermore, the main sleeve is provided with gears, a motor, a memory card slot and a data processor for driving the movement of the annular sensitive voltage ranging device. The gears are connected through the tooth grooves and are driven by the motor. When the motor is not working, the integrated data processor is connected to the annular sensitive voltage ranging device through the data line in the memory card slot. A memory card is inserted in the memory card slot, which can store the detection data of the annular sensitive voltage ranging device.

[0013] Furthermore, the annular sensitive voltage ranging device is a highly sensitive voltmeter. When the composite slurry is injected into the anchor hole and fully penetrates the anchor hole, the electrode sheet energizes the slurry in the hole, and current is generated in the slurry. At this time, the annular sensitive voltage ranging device slides on the entire rod body through gears to detect the distance from the crack surface to the annular sensitive voltage ranging device. After multiple detections, the position data can be calculated accordingly using the data processor based on the generated distance data.

[0014] A method for using a thermal imaging sensing device for drilling cracks, comprising the following steps:

[0015] Drill anchor holes at pre-marked locations in the surrounding rock, insert the main sleeve into the anchor holes, and then securely connect the grouting vessel, high-pressure air pump, and grouting pipe via a piston switch.

[0016] The composite slurry containing electrolyte ions is stirred evenly in the grouting vessel, and then the grouting vessel is closed and the high-pressure air pump is started. The composite slurry containing electrolyte ions is injected into the anchor hole through the high-pressure nozzle, and the motor is started to detect the distance from the crack surface to the annular sensitive voltage ranging device;

[0017] During this process, the annular sensitive voltage ranging device will detect the distance change data generated by the composite slurry containing electrolyte ions that penetrates into the cracks. The position information of each section of the anchor hole will be recorded and stored in the memory card in the memory card slot. The data will be transmitted to the data processor through the data line. The memory card and the data processor are connected through the storage line in the memory card slot. The data processor will calculate the distance change data based on the cross-sectional position information, and then re-synthesize it based on the cross-sectional position information. Finally, the imaging computer will use algorithm analysis, data filtering, image processing and other technologies to draw a three-dimensional map of the anchor hole cracks.

[0018] Beneficial effects: The present invention can accurately detect the existence, opening and direction of cracks in anchor holes and evaluate their impact on the project, so as to take corresponding preventive measures or appropriately adjust the design scheme. By detecting cracks through sensitive voltage ranging, it avoids the limitation of imaging resolution. Due to the good conductivity of the composite slurry containing electrolyte ions in the anchor hole, the actual direction of the cracks in the surrounding rock can be detected. It can accurately detect the opening size and development of the surrounding rock cracks from the actual on-site project, making up for the disadvantage that the azimuth of the cracks and the exact position in the formation cannot be known by coring. The present invention has a simple structure, accurate detection, and stable function. It can greatly improve the evaluation efficiency, eliminate potential threats, and thus effectively reduce the occurrence of accidents and ensure the life safety of workers. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of drilling in an embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the structure of a thermal imaging sensing device for drilling cracks in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the installation of a thermal imaging sensing device for drilling cracks according to an embodiment of the present invention;

[0022] FIG4( a ) is a schematic cross-sectional view of a main rod slideway structure section in an embodiment of the present invention;

[0023] FIG4( b ) is a schematic cross-sectional view of a sensitive voltage ranging device according to an embodiment of the present invention;

[0024] FIG4( c ) is a schematic cross-sectional view of a grouting hole according to an embodiment of the present invention;

[0025] Figure 5 2. A three-dimensional schematic diagram of an electrode sheet of a sensitive voltage ranging device according to an embodiment of the present invention;

[0026] Figure 6 This is a three-dimensional schematic diagram of the end of the main rod body in an embodiment of the present invention;

[0027] Figure 7 This is a schematic cross-sectional view of the injection of a composite slurry containing electrolyte ions according to an embodiment of the present invention;

[0028] In the figure: 1-surrounding rock, 2-data line, 3-motor, 4-crack, 5-storage line, 6-main rod, 7-tooth groove, 8-annular sensitive voltage ranging device, 9-high-pressure nozzle, 10-electrode line, 11-electrode hole, 12-pore pressure sensing device, 13-electrode sheet, 14-gear, 15-storage card slot, 16-grouting pipe, 17-retractable micro spring, 18-insulating shell, 19-anchor hole, 20-annular grouting plug, 21-data processor, 22-tray, 23-anti-slip wire nut, 24-threaded segment, 25-piston switch, 26-instrument panel, 27-sensitive transformer, 28-main sleeve, 29-imaging computer, 30-electrode line slot, 31-grouting hole slot, 32-composite slurry. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the embodiments in the accompanying drawings:

[0030] like Figure 1 、 Figure 2 and Figure 3 As shown, the present invention discloses a thermal imaging sensing device for drilling cracks, which includes a main rod body 6, a sensitive voltage ranging device 8 and a main body sleeve 28.

[0031] The main rod body 6 is a hollow, porous structure, divided into a nozzle structure and a discharge structure along the axis. Four grouting pipes 16 are evenly spaced along the circumference of the main rod body 6. Grouting holes 32 are provided at the connection between the grouting pipes and the nozzles. The grouting pipes 16 can inject a composite slurry 32 containing electrolyte ions. The discharge structure is an electrode hole 11 with a rectangular tubular structure. The electrode wire 10 is connected to the sensitive transformer 27. The sensitive transformer 27 can adjust the current in real time through the instrument panel 26. The head of the discharge structure is equipped with an electrode sheet 13, which can release voltage to inject current into the composite slurry 32 containing electrolyte ions in the hole, as shown in Figures 4(a), 4(b), and 4(c).

[0032] The tail section of the main rod is provided with a tray 22 and an anti-slip nut 23 through a thread 24. The head of the main rod body 6 is provided with a pore pressure sensing device 12. The pore pressure sensing device 12 is connected to a retractable micro spring 17, which can detect the pore pressure inside the pore after grouting in real time. The nozzle structure section of the main rod body 6 is set at the end, and the grouting pipe 16 is connected to the high-pressure nozzle 9. The high-pressure nozzle 9 is provided with an annular fiber mesh 8, the purpose of which is to make the high-pressure slurry spray out in all radial directions along the circumference. An annular slurry stopper 20 is provided in the rod body to prevent the injected composite slurry from penetrating into the interior of the rod body. The outer surface of the rod body adopts an insulating shell 18 to prevent the generation of current on the surface of the rod body after power is turned on.

[0033] A tooth groove 7 is provided on the surface of the main rod body, and a gear 14 is embedded on the surface of the annular sensitive voltage ranging device 8. The gear 14 can slide in the tooth groove 7, driving the annular sensitive voltage ranging device 8 to slide within the entire length of the rod body. The gear 14 is connected to the motor 3, which can control the sliding speed of the gear.

[0034] The electrolyte ions in the composite slurry 32 have a conductive effect and can generate current in the slurry after being energized. The annular sensitive voltage ranging device 8 generates voltage based on the current in the slurry. The principle that the farther the distance is, the greater the voltage is under constant current can detect the distance from the inner surface of the crack to the rod body, and then calculate the size and shape of the anchor hole, thereby realizing crack detection.

[0035] like Figure 3 As shown, the method and steps of use are as follows: first, drill an anchor hole 19 at a pre-marked position in the surrounding rock 1, insert the main sleeve 28 into the anchor hole 19, and then connect the external pipeline to the grouting pipe 16 through the piston switch (25). The external pipeline connected to the grouting pipe 16 should first be connected to the grouting vessel and then to the high-pressure air pump, and the slurry should be sprayed out through the high-pressure nozzle 9;

[0036] The composite slurry 32 containing electrolyte ions is stirred evenly in a grouting vessel, and then the grouting vessel is closed and the high-pressure air pump is started. The composite slurry (32) is sprayed into the anchor hole (19) through the high-pressure nozzle (12) as needed and fills the entire anchor hole (19) until the pressure reaches a preset value. At this time, the composite slurry 32 fills the crack 4, and the motor (3) is started. The gear (18) drives the annular sensitive voltage ranging device (8) to move on the surface of the rod body;

[0037] At this time, the annular sensitive voltage ranging device 8 should always be in the on state. The annular sensitive voltage ranging device will detect the distance change data generated by the composite slurry 32 containing electrolyte ions that penetrates into the cracks 14. The position information of each section of the anchor hole 19 will be recorded and stored in the memory card in the memory card slot 15. The data will be transmitted to the data processor 21 through the data line 2. The memory card and the data processor 21 are connected through the storage line 5 in the memory card slot. The data processor 21 will calculate the distance change data based on the cross-sectional position information, and then resynthesize it based on the cross-sectional position information. Finally, the imaging computer 29 uses algorithm analysis, data filtering, image processing and other technologies to draw a three-dimensional map of the anchor hole crack.

[0038] like Figure 6 and Figure 2As shown, the main sleeve 28 is a hollow rod, partially embedded in the anchor hole 19. The main sleeve 28 is equipped with a gear 14, a motor 3, a memory card slot 15, and a data processor 21. The gear 14 is connected via a tooth groove 7 and is controlled and driven by the motor 3. When the motor is not working, the gear can rotate freely. The head of the rod is equipped with a pore pressure sensing device 12, which is connected to a retractable micro-spring 17 to prevent excessive pressure in the hole after high-pressure grouting. The rod is equipped with an annular grouting stopper 20 to prevent the injected composite grout from leaking out. The rod is covered with an insulating shell 18 to prevent current from being generated on the rod surface after power is applied. The integrated data processor 21 is connected to the annular sensitive voltage ranging device 8 via a data line in the memory card slot 15. A memory card is inserted into the memory card slot 15 to store the detection data of the annular sensitive voltage ranging device 8.

[0039] like Figure 2 、 Figure 5 and Figure 6 As shown, the sensitive voltage ranging system includes a ring-shaped sensitive voltage ranging device 8, a memory card slot 15, a data processor 21, and an imaging computer 29. The ring-shaped sensitive voltage ranging device 8 is a highly sensitive voltmeter. After slurry is injected into the anchor hole 19 and fully penetrates the anchor hole 19, the electrode sheet 13 energizes the slurry in the hole, generating a current in the slurry. At this time, the ring-shaped sensitive voltage ranging device 8 slides across the entire rod body via gears, detecting the distance from the inner surface of the anchor hole crack to the ring-shaped sensitive voltage ranging device 8, thereby detecting the presence, opening, and direction of the crack in the anchor hole 19 and assessing its impact on the project. After multiple detections, the data processor 21 can calculate the corresponding position data based on the generated distance data.

[0040] The data processor 21 is mounted at the end of the main sleeve 28 and is connected to the annular sensitive voltage ranging device 8 via a data cable within the memory card slot 15. As the gear 18 propels the annular sensitive voltage ranging device 8 across the rod surface, the positional information of each cross-section of the anchor hole 19 is recorded and stored on a memory card within the memory card slot 15. The memory card is connected to the data processor 21 via a storage cable 5 within the memory card slot. The data processor 21 calculates the distance change data based on the cross-section position information and then re-synthesizes it based on the cross-section position information. The data processor 21 is then connected to an imaging computer 29, which uses algorithmic analysis, data filtering, and image processing techniques to create a three-dimensional image of the anchor hole fracture.

[0041] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A sensitive voltage ranging device for drilling cracks, characterized by: The invention comprises a main rod body (6) and a sensitive transformer (27), wherein the main rod body (6) is a hollow multi-porous tubular structure, the outer side of the main rod body (6) is wrapped with an insulating shell (18), the end of the main rod body (6) is provided with a discharge structure and a plurality of high-pressure nozzles (9), the area of ​​the main rod body (6) other than the discharge structure and the plurality of high-pressure nozzles (9) is sleeved with an insulating main body sleeve (28), a movable annular sensitive voltage ranging device (8) is provided on the main body sleeve (28), and a threaded section (24) is provided on the outer side of the tail section of the main body sleeve (28), and a tray (22) and an anti-slip nut (23) are connected via the threaded section (24); Four axially arranged grouting slots (31) are evenly distributed along the circumference of the outer side of the main rod body (6), each grouting slot (31) is provided with a grouting pipe (16), the grouting pipe (16) is connected to the grouting vessel through a piston switch (25), and the end of each grouting pipe (16) is connected to a high-pressure nozzle (9), which is located near the end of the main rod body (6), and a composite slurry (32) containing electrolyte ions is injected into the high-pressure nozzle (9) through the grouting pipe (16); The discharge structure comprises two electrode line slots (30) extending from the end of a main rod body (6) and bending back to form a C shape and symmetrically arranged. Each electrode line slot (30) is provided with an electrode hole (11) and an electrode sheet (13) at the end. Two electrode line slots (30) communicating with the electrode holes (11) are provided in the main rod body (6); the two electrode sheets (13) are respectively connected to the ends of two electrode wires (10) arranged through the electrode holes (11) and the electrode line slots (30); the tail ends of the two electrode wires (10) are connected to a sensitive transformer (27); and the electrode sheets (13) are used to inject current into a composite slurry (32) containing electrolyte ions ejected from a high-pressure nozzle (9); A pore pressure sensing device (12) is provided in the middle of the end of the main rod body (6) via a retractable micro spring (17) for detecting the pore pressure inside the pore after grouting; Two tooth grooves (7) are formed on the surface of the main sleeve (28). An annular sensitive voltage distance measuring device (8) capable of moving along the main sleeve (28) is connected to the two tooth grooves (7) via gears (14). The gears (14) are driven by a motor (3) provided on the main rod (6) to drive the annular sensitive voltage distance measuring device (8).

2. The sensitive voltage ranging device for drilling cracks according to claim 1, characterized in that: The electrolyte ions in the composite slurry (32) have a conductive effect. After the composite slurry (32) is injected into the borehole, discharge is conducted by using the discharge structure to generate current in the composite slurry (32). The annular sensitive voltage distance measuring device (8) detects the distance from the inner surface of the crack (4) of the surrounding rock (1) to the main rod body (6) based on the voltage signal detected from the composite slurry (32) and the principle that the voltage increases with distance under constant current, thereby realizing crack (4) detection.

3. The sensitive voltage ranging device for drilling cracks according to claim 1, characterized in that: An annular fiber mesh is provided on the high-pressure nozzle (9), so that the high-pressure slurry ejected by the high-pressure nozzle (9) can only be ejected along the circumference and radial directions. The main sleeve (28) is provided with an annular slurry stopper (20) on the outer cover of the crack (4) detection area to prevent the injected composite slurry (32) from penetrating into the interior of the main rod body (6).

4. The sensitive voltage ranging device for drilling cracks according to claim 1, characterized in that: A gear (14) for driving the annular sensitive voltage ranging device (8) to move, a motor (3), a memory card slot (15) and a data processor (21) are provided on the main body sleeve (28). The gear (14) is connected via a tooth groove (7) and is regulated and driven by the motor (3). When the motor is not working, the data processor (21) is connected to the annular sensitive voltage ranging device (8) via a data line (2) in the memory card slot (15). A memory card is inserted in the memory card slot (15) and can store detection data of the annular sensitive voltage ranging device (8).

5. The sensitive voltage ranging device for drilling cracks according to claim 1, characterized in that: The annular sensitive voltage distance measuring device (8) is a highly sensitive voltmeter. When the composite slurry (32) fills the anchor hole (19) and fully penetrates the anchor hole (19), the electrode sheet (13) energizes the composite slurry (32) in the hole, and current is generated in the composite slurry (32). At this time, the annular sensitive voltage distance measuring device (8) slides on the entire rod body through the gear, and uses electrical signals to detect the voltage from the inner surface of the crack (4) to the annular sensitive voltage distance measuring device (8). The greater the generated voltage, the farther the distance. After multiple detections, the data processor (21) can calculate the corresponding position data based on the generated distance data.

6. A method for using the thermal imaging sensing device for drilling cracks according to any one of claims 1 to 5, characterized in that: Here are the steps: Drill an anchor hole (19) at a pre-marked position of the surrounding rock (1), insert the main sleeve (28) into the anchor hole (19), and then connect the grouting vessel, high-pressure air pump and grouting pipe (16) via a piston switch (25); The composite slurry (32) containing electrolyte ions is stirred evenly in a grouting vessel, and then the grouting vessel is closed and a high-pressure air pump is started. The composite slurry (32) containing electrolyte ions is filled into the anchor hole (19) through a high-pressure nozzle (9), so that the crack (4) is also filled with the composite slurry (32). The electrode sheet (13) is used to energize the composite slurry (32) in the hole to generate current, and the motor (3) is started. The gear (14) drives the annular sensitive voltage distance measuring device (8) to move on the rod surface; thereby detecting the distance from the inner surface of the crack (4) in the anchor hole (19) to the annular sensitive voltage distance measuring device (8); During this process, the annular sensitive voltage distance measuring device will detect the distance change data generated by the composite slurry (32) containing electrolyte ions that penetrates the crack (4). The position information of each cross section of the anchor hole (19) will be recorded and stored in the memory card in the memory card slot (15). The data will be transmitted to the data processor (21) through the data line (2). The memory card and the data processor (21) are connected through the storage line (5) in the memory card slot. The data processor (21) will calculate the distance change data based on the cross section position information, and then resynthesize it based on the cross section position information. Finally, the imaging computer (29) adopts algorithm analysis, data filtering, image processing and other technologies to draw a three-dimensional map of the anchor hole crack.

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