Bottom expansion and filling integrated anchoring monitoring device and method based on electromagnetic ultrasonic technology

Abstract

The integrated anchor monitoring device for bottom expansion and filling based on electromagnetic ultrasonic technology includes a drilling, expansion and injection integrated device, an anchoring assembly and an electromagnetic ultrasonic monitoring device; the drilling, expansion and injection integrated device is connected to a high-pressure pump station after drilling an anchor hole of a certain depth on the top of the mine tunnel, and the high-pressure pump station injects high-pressure slurry into the filling area of ​​the surrounding rock through the drilling, expansion and injection integrated device; the anchoring assembly is anchored in the anchor hole, and an electromagnetic excitation coil and an induction receiving coil are wound around the anchoring assembly; the electromagnetic ultrasonic monitoring device is respectively connected to the electromagnetic excitation coil and the induction receiving coil through a signal wire. The present invention integrates drilling, expansion and injection into one device, saves costs, greatly simplifies the operating procedures, has a good hole protection effect, uses electromagnetic ultrasonic technology to monitor the mine tunnel support situation in real time with high precision and in all directions, and the monitoring data can be stored and copied, which is conducive to scientific researchers to collect on-site monitoring data and further study and analyze the support situation.

Description

Technical Field

[0001] The present invention relates to the field of mining engineering and underground engineering, and in particular to a bottom expansion and filling integrated anchoring monitoring device and method based on electromagnetic ultrasonic technology. Background Art

[0002] Anchor support is widely used in coal mine tunnel support. The tensile force of the structure is transmitted through the shearing action between the anchor and the coal rock mass, thereby improving the mechanical properties and bearing capacity of the surrounding rock of the supporting tunnel, thereby achieving the function of supporting the tunnel. At present, anchor support is not only used in mines, but also in engineering technology to reinforce the main body of slopes, tunnels, and dams.

[0003] The coal seams and roof and floor rock strata in the soft rock tunnels are poorly cemented, showing characteristics such as low strength of the coal and rock masses, looseness and fragmentation, easy weathering, easy collapse, and swelling when exposed to water. This makes it difficult to support the mine tunnels. Most tunnels have to be renovated many times during their service life, which seriously affects the normal progress of mining work. Not only is the support cost high, but it also poses a great safety threat.

[0004] At present, there are two main ways to improve the anchoring performance of anchor bolts: increasing the anchoring length and expanding the bottom of the anchor hole. Increasing the anchoring length improves the anchoring force to a certain extent, but this method does not change the surrounding rock properties of the anchor hole, and does not fundamentally improve the anchoring effect of the anchoring system, so the anchoring force improvement effect is not obvious; while expanding the bottom of the anchor hole can significantly improve the anchoring force of the anchor in theory, but the size of the expansion of the bottom of the anchor hole affects the stirring effect of the anchoring agent in the hole, which in turn affects the anchoring effect of the anchoring system.

[0005] Bottom expansion and backfilling anchoring is a new method to improve the anchoring performance of anchor bolts. Bottom expansion and backfilling is to expand the bottom of the anchor hole into a predetermined shape, and fill the expanded part with high-strength materials while retaining the original anchor hole to improve the physical and mechanical properties of the borehole surrounding rock in the anchoring section, thereby achieving the purpose of increasing the bonding ability between the anchor and the borehole surrounding rock.

[0006] The current bottom expansion and backfilling anchoring equipment mainly includes threaded-driven reaming drill rods for mining anchor holes and surrounding rock reinforcement grouting equipment. That is, the reaming drill rod is first used to expand the hole, and then the grouting equipment is used to grout. The reaming drill rod needs to be pulled out before grouting. The operation process is relatively complicated, and hole collapse is very likely to occur in soft surrounding rocks.

[0007] With the widespread use of anchor bolt support systems, monitoring the health status of anchor bolt systems is becoming increasingly important. Traditional monitoring methods are mainly pull-out tests and coring methods. Both methods are destructive, slow, and inefficient. Only a small amount of sampling can be performed to determine the overall situation, which is prone to missed detection.

[0008] Ultrasonic guided wave technology based on the principle of magnetostriction is a new ultrasonic guided wave non-destructive monitoring method. Compared with traditional ultrasonic monitoring technology, electromagnetic ultrasonic monitoring has the advantages of high accuracy, no need for coupling agent, non-contact, suitable for high temperature monitoring, and easy to excite various ultrasonic waveforms. Compared with traditional anchor monitoring methods, electromagnetic ultrasonic monitoring has the characteristics of fast, convenient, and long-distance monitoring. It is a new research direction in the field of non-destructive monitoring, but it is currently less used in mines. Summary of the invention

[0009] The purpose of the present invention is to provide an integrated anchor monitoring device and method for bottom expansion and filling based on electromagnetic ultrasonic technology. The present invention integrates drilling, expansion and injection in one device, saves costs, greatly simplifies the operating procedures, and has a good hole protection effect. Electromagnetic ultrasonic technology is used to perform high-precision, all-round and real-time monitoring of the support conditions of mine tunnels. The monitoring data can be stored and copied, which is beneficial for scientific researchers to collect on-site monitoring data and further study and analyze the support conditions.

[0010] To achieve the above object, the present invention adopts the following technical solution:

[0011] An integrated anchoring monitoring device for bottom expansion and filling based on electromagnetic ultrasonic technology, including drilling, expansion and injection integrated equipment, anchoring components and electromagnetic ultrasonic monitoring equipment;

[0012] The drilling, expansion and injection integrated equipment drills an anchor hole of a certain depth on the top of the mine tunnel and connects it to the high-pressure pump station after expanding the hole. The high-pressure pump station injects high-pressure slurry into the filling area of ​​the surrounding rock around the anchor hole through the drilling, expansion and injection integrated equipment;

[0013] The anchoring assembly is anchored in the anchoring hole, and an electromagnetic excitation coil and an induction receiving coil are wound around the anchoring assembly;

[0014] The electromagnetic ultrasonic monitoring equipment is connected to the electromagnetic excitation coil and the induction receiving coil through signal wires respectively. The electromagnetic ultrasonic monitoring equipment applies an AC signal to the electromagnetic excitation coil. The electromagnetic excitation coil induces an alternating magnetic field. The induction receiving coil generates an induced voltage under the action of the alternating magnetic field and transmits it to the electromagnetic ultrasonic monitoring equipment.

[0015] The drilling, expansion and injection equipment includes a hollow drill bit and a hole protection casing. The hollow drill bit is a conical structure with a thin front and a thick back. The rear end of the hollow drill bit is fixedly connected with the front end of the hole protection casing. The maximum diameter of the hollow drill bit is slightly larger than the outer diameter of the hole protection casing. A plurality of funnel-shaped grouting ports that are transparent inside and outside and are larger outside and smaller inside are evenly arranged on the outer circumference of the hollow drill bit and the outer circumference of the middle front side of the hole protection casing. Three knife grooves are arranged on the outer circumference of the hollow drill bit. The three knife grooves are arranged in a circumferential array. The hollow drill bit is arranged in a manner that the knife groove is arranged along the generatrix direction of the hollow drill bit, a hole reaming blade is arranged in each knife groove, the rear end of the hole reaming blade is hinged in the knife groove at the connection between the hollow drill bit and the hole protection sleeve through a pin shaft, the pin shaft is perpendicular to the center line of the hole protection sleeve, the diameter of the pin shaft is greater than the thickness of the hole protection sleeve, and the side of the pin shaft close to the center line of the hole protection sleeve is located in the hole protection sleeve and the hollow drill bit, the hole protection sleeve is fixed in the anchor hole, and the rear end of the hole protection sleeve is flush with the hole opening of the anchor hole.

[0016] The anchoring assembly includes an anchor rod, a gasket and a nut. The diameter of the anchor rod is the same as the inner diameter of the hole protection casing, the length of the anchor rod is greater than the length of the hole protection casing, the electromagnetic excitation coil is wound and fixed on the outer circumference of the front end of the anchor rod, the induction receiving coil is wound and fixed on the outer circumference of the rear end of the anchor rod, the outer circumference of the anchor rod is provided with an external thread, the anchor rod is anchored in the hole protection casing, the front end of the anchor rod extends into the hole protection casing and is flush with the front end of the hole protection casing, the rear end of the anchor rod extends out of the rear end of the hole protection casing, the gasket is sleeved on the rear side of the anchor rod and is in tight contact with the roof of the mine tunnel, and the nut is threadedly connected to the rear side of the anchor rod and is in tight contact with the gasket.

[0017] An AC signal transmission button and a safety value setting button are provided at the lower front part of the electromagnetic ultrasonic monitoring device, a display is provided at the upper front part of the electromagnetic ultrasonic monitoring device, an alarm and a USB data interface are provided at the top of the electromagnetic ultrasonic monitoring device, and the safety value setting button is connected to the alarm signal.

[0018] The monitoring method of the bottom expansion and backfilling integrated anchoring monitoring device based on electromagnetic ultrasonic technology specifically includes the following steps:

[0019] (1) Use drilling, expansion and injection equipment to drill anchor holes of a certain depth on the top of the mine tunnel;

[0020] (2) Use drilling, expansion and injection equipment to expand the bottom of the anchor hole;

[0021] (3) Grouting into the filling area of ​​the surrounding rock;

[0022] (4) Anchor the anchor rod in the anchor hole;

[0023] (5) Monitor the anchoring effect using electromagnetic ultrasonic monitoring equipment.

[0024] Step (1) specifically comprises: using a hollow drill bit to drill to a specified depth at the top of a mine tunnel, thereby drilling an anchor hole, fixing a hole protection casing in the anchor hole, and protecting the anchor hole, so that the rear end of the hole protection casing is flush with the hole mouth of the anchor hole.

[0025] Step (2) is specifically as follows: use a push rod with a tapered front end to push it into the hole protection casing, insert the front end of the push rod into the hollow drill bit and squeeze the three pins, so that the three reaming blades are ejected to the specified angle at the same time, and then the hollow drill bit continues to rotate, so that the three reaming blades expand the bottom of the anchor hole, so that the anchor hole is formed into an inverted cone hole with a larger inside and a smaller outside. After the hole expansion is completed, the hollow drill bit stops rotating, and the push rod is pulled out, so that the three pins are no longer squeezed, and the three reaming blades are respectively retracted into the three tool grooves.

[0026] Step (3) is specifically as follows: the rear end of the hole protection casing is connected to the high-pressure pump station, and the high-pressure pump station pumps high-pressure slurry into the hole protection casing. The high-pressure slurry is evenly injected into the filling area of ​​the surrounding rock around the anchor hole through the hollow drill bit and the funnel-shaped grouting ports on the hole protection casing.

[0027] Step (4) is specifically as follows: after the grouting is completed, the hole protection casing and the high-pressure pump station are separated, and the hole sealer is installed in the middle of the outer circumference of the hole protection casing to seal the gap between the anchor hole and the hole protection casing to prevent the slurry from flowing out and affecting the anchoring effect. The anchor rod is directly driven into the hole protection casing so that the front end of the anchor rod is flush with the front end of the hole protection casing, and the rear end of the anchor rod extends out of the rear end of the hole protection casing. The gasket is put on the rear side of the anchor rod and pressed into contact with the roof of the mine tunnel. The nut is threadedly connected to the rear side of the anchor rod and pressed into contact with the gasket, so that the anchor rod is firmly anchored.

[0028] Step (5) is specifically as follows: the button for applying AC signal transmission is pressed, and the electromagnetic ultrasonic monitoring device applies AC signal to the electromagnetic excitation coil. The electromagnetic excitation coil induces an alternating magnetic field. The alternating magnetic field acts on the anchor rod, and a stress wave is generated in the anchor rod. The stress wave is reflected and refracted and then transmitted backward in the form of guided wave. The guided wave causes the spatial magnetic field to change. The induction receiving coil generates an induced voltage under the action of the alternating magnetic field, which is transmitted to the electromagnetic ultrasonic monitoring device in the form of an electrical signal. After receiving the electrical signal, the electromagnetic ultrasonic monitoring device processes it and displays the processed image through the display. At the same time, the processed image and data are stored in the storage of the electromagnetic ultrasonic monitoring device. The staff inserts the U disk into the USB data interface as needed, copies the data to the U disk, and then inserts the U disk into the computer to further analyze the data. The staff manually sets or modifies the safety value through the safety value setting button. When the received monitoring data exceeds the safety value, the alarm is triggered to automatically alarm.

[0029] Compared with the prior art, the present invention has outstanding substantial features and significant progress. Specifically, the present invention uses the same equipment for drilling and reaming. When the hollow drill bit is drilling, the hole-guarding casing is drilled together with the hollow drill bit. During the drilling process, three hole-reamer blades are stored in three knife grooves. After the hollow drill bit is drilled to a specified depth, the three hole-reamer blades are simultaneously controlled to unfold by the wire rope on the hollow drill bit to expand the bottom of the anchor hole. After that, the hole-guarding casing is fixedly supported in the anchor hole, and the rear end of the hole-guarding casing is connected to the high-pressure pump station. The high-pressure pump station pumps high-pressure slurry into the hole-guarding casing. It will be evenly injected into the filling area of ​​the surrounding rock around the anchor hole through the hollow drill bit and the funnel-shaped grouting ports on the hole protection casing. After the grouting is completed, the anchor rod will be directly driven into the hole protection casing for anchoring. The electromagnetic ultrasonic monitoring equipment can monitor the support conditions of the mine tunnels in real time with high precision and in all directions, effectively avoiding missed detection. The alarm can be used to timely determine the support conditions of the mine tunnels and take corresponding measures. The monitoring data can be stored and copied so that scientific researchers can collect on-site monitoring data to further study and analyze the support conditions, save costs, greatly simplify the operating procedures, and achieve good hole protection effects.

[0030] The present invention integrates drilling, expanding and injection into one device, which saves costs, greatly simplifies the operating procedures, has a good hole protection effect, and uses electromagnetic ultrasonic technology to monitor the mine tunnel support conditions in real time with high precision and in all directions. The monitoring data can be stored and copied, which is beneficial for scientific researchers to collect on-site monitoring data and further study and analyze the support conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a working schematic diagram of the present invention.

[0032] Figure 2 It is a schematic diagram of the assembly structure of the drilling, expansion and injection integrated equipment and the anchor rod of the present invention.

[0033] Figure 3 It is an assembly perspective view of the drilling, expansion and injection integrated equipment and the anchor rod of the present invention.

[0034] Figure 4 It is a schematic structural diagram of the hollow drill bit and the hole protection sleeve when the hole expansion blade of the present invention has not been ejected.

[0035] Figure 5 It is a schematic structural diagram of a hollow drill bit and a hole protection sleeve when the hole expansion blade of the present invention pops out. DETAILED DESCRIPTION

[0036] The embodiments of the present invention are further described below with reference to the accompanying drawings.

[0037] like Figure 1-Figure 5 As shown, the bottom expansion and backfilling integrated anchoring monitoring device based on electromagnetic ultrasonic technology includes a drilling, expansion and injection integrated device, an anchoring component and an electromagnetic ultrasonic monitoring device 1;

[0038] The drilling, expanding and injecting integrated equipment drills an anchor hole of a certain depth at the top of the mine tunnel and expands the hole before connecting it to a high-pressure pump station (not shown). The high-pressure pump station injects high-pressure slurry into the filling area of ​​the surrounding rock 2 around the anchor hole through the drilling, expanding and injecting integrated equipment.

[0039] The anchoring assembly is anchored in the anchoring hole, and an electromagnetic excitation coil 3 and an induction receiving coil 4 are wound around the anchoring assembly;

[0040] The electromagnetic ultrasonic monitoring device 1 is connected to the electromagnetic excitation coil 3 and the induction receiving coil 4 through the signal wire 5 respectively. The electromagnetic ultrasonic monitoring device 1 applies an AC signal to the electromagnetic excitation coil 3, and the electromagnetic excitation coil 3 induces an alternating magnetic field. The induction receiving coil 4 generates an induced voltage under the action of the alternating magnetic field and transmits it to the electromagnetic ultrasonic monitoring device 1.

[0041] The drilling, expanding and grouting integrated equipment comprises a hollow drill bit 6 and a hole-protecting casing 7. The hollow drill bit 6 is a conical structure with a thin front and a thick back. The rear end of the hollow drill bit 6 is integrally fixedly connected with the front end of the hole-protecting casing 7. The maximum diameter of the hollow drill bit 6 is slightly larger than the outer diameter of the hole-protecting casing 7. A plurality of funnel-shaped grouting ports 8 which are transparent inside and outside and are larger outside and smaller inside are evenly arranged on the outer circumference of the hollow drill bit 6 and the outer circumference of the front side of the middle part of the hole-protecting casing 7. Three knife grooves 9 are arranged on the outer circumference of the hollow drill bit 6. The three knife grooves 9 are arranged in a circumferential array. The knife grooves 9 are arranged along the outer circumference of the hollow drill bit 6. The hollow drill bit 6 is arranged in the direction of the generatrix, and a reaming blade 10 is arranged in each cutter groove 9. The rear end of the reaming blade 10 is hinged in the cutter groove 9 at the connection between the hollow drill bit 6 and the hole protection sleeve 7 through a pin shaft 19. The pin shaft 19 is perpendicular to the center line of the hole protection sleeve 7. The diameter of the pin shaft 19 is greater than the thickness of the hole protection sleeve 7 and the side of the pin shaft 19 close to the center line of the hole protection sleeve 7 is located in the hole protection sleeve 7 and the hollow drill bit 6. The hole protection sleeve 7 is fixed in the anchor hole, and the rear end of the hole protection sleeve 7 is flush with the hole mouth of the anchor hole.

[0042] The anchoring assembly includes an anchor rod 11, a gasket 12 and a nut 13. The diameter of the anchor rod 11 is the same as the inner diameter of the hole protection casing 7. The length of the anchor rod 11 is greater than the length of the hole protection casing 7. The electromagnetic excitation coil 3 is wound and fixed on the outer circumference of the front end of the anchor rod 11, and the induction receiving coil 4 is wound and fixed on the outer circumference of the rear end of the anchor rod 11. The outer circumference of the anchor rod 11 is provided with an external thread. The anchor rod 11 is anchored in the hole protection casing 7. The front end of the anchor rod 11 extends into the hole protection casing 7 and is flush with the front end of the hole protection casing 7. The rear end of the anchor rod 11 extends out of the rear end of the hole protection casing 7. The gasket 12 is sleeved on the rear side of the anchor rod 11 and is in tight contact with the roof of the mine tunnel. The nut 13 is threadedly connected to the rear side of the anchor rod 11 and is in tight contact with the gasket 12.

[0043] An AC signal transmission button 14 and a safety value setting button 15 are provided at the lower front part of the electromagnetic ultrasonic monitoring device 1, a display 16 is provided at the upper front part of the electromagnetic ultrasonic monitoring device 1, an alarm 17 and a USB data interface 18 are provided at the top of the electromagnetic ultrasonic monitoring device 1, and the safety value setting button 15 is connected to the alarm 17 signal.

[0044] The monitoring method of the bottom expansion and backfilling integrated anchoring monitoring device based on electromagnetic ultrasonic technology specifically includes the following steps:

[0045] (1) Use drilling, expansion and injection equipment to drill anchor holes of a certain depth on the top of the mine tunnel;

[0046] (2) Use drilling, expansion and injection equipment to expand the bottom of the anchor hole;

[0047] (3) Grouting into the filling area of ​​surrounding rock 2;

[0048] (4) Anchoring the anchor rod 11 in the anchor hole;

[0049] (5) Monitor the anchoring effect using the electromagnetic ultrasonic monitoring device 1.

[0050] Step (1) specifically comprises: using a hollow drill bit 6 to drill to a specified depth at the top of a mine tunnel, thereby drilling an anchor hole, fixing a hole protection sleeve 7 in the anchor hole, protecting the anchor hole, and making the rear end of the hole protection sleeve 7 flush with the hole mouth of the anchor hole.

[0051] Step (2) is specifically as follows: use a push rod 20 with a tapered front end to push it into the hole protection sleeve 7, insert the front end of the push rod 20 into the hollow drill bit 6 and squeeze the three pins 19, so that the three reaming blades 10 are ejected to the specified angle at the same time, and then the hollow drill bit 6 continues to rotate, so that the three reaming blades 10 expand the bottom of the anchor hole, so that the anchor hole is formed into an inverted cone hole with a larger inside and a smaller outside. After the expansion is completed, the hollow drill bit 6 stops rotating, and the push rod 20 is pulled out, so that the three pins 19 are no longer squeezed, and the three reaming blades 10 are respectively retracted into the three tool grooves 9.

[0052] Step (3) specifically comprises: connecting the rear end of the hole protection casing 7 to the high-pressure pump station, and the high-pressure pump station pumps high-pressure slurry into the hole protection casing 7. The high-pressure slurry is evenly injected into the filling area of ​​the surrounding rock 2 around the anchor hole through the hollow drill bit 6 and the funnel-shaped grouting ports 8 on the hole protection casing 7.

[0053] Step (4) is specifically as follows: after the grouting is completed, the hole protection casing 7 is separated from the high-pressure pump station, and the hole sealer 21 is installed in the middle of the outer circumference of the hole protection casing 7 to seal the gap between the anchor hole and the hole protection casing 7 to prevent the slurry from flowing out and affecting the anchoring effect. The anchor rod 11 is directly driven into the hole protection casing 7 so that the front end of the anchor rod 11 is flush with the front end of the hole protection casing 7, and the rear end of the anchor rod 11 extends out of the rear end of the hole protection casing 7. The gasket 12 is put on the rear side of the anchor rod 11 and pressed into contact with the top of the mine tunnel. The nut 13 is threadedly connected to the rear side of the anchor rod 11 and pressed into contact with the gasket 12, so that the anchor rod 11 is firmly anchored.

[0054] Step (5) is specifically as follows: the AC signal transmission button 14 is pressed, and the electromagnetic ultrasonic monitoring device 1 applies an AC signal to the electromagnetic excitation coil 3. The electromagnetic excitation coil 3 induces an alternating magnetic field. The alternating magnetic field acts on the anchor rod 11, and a stress wave is generated in the anchor rod 11. The stress wave is reflected and refracted and then transmitted backward in the form of a guided wave. The guided wave causes the spatial magnetic field to change. The induction receiving coil 4 generates an induced voltage under the action of the alternating magnetic field, which is transmitted to the electromagnetic ultrasonic monitoring device 1 in the form of an electrical signal. After receiving the electrical signal, the electromagnetic ultrasonic monitoring device 1 processes it and displays the processed image through the display 16. At the same time, the processed image and data are stored in the storage of the electromagnetic ultrasonic monitoring device 1. The staff inserts the U disk into the USB data interface 18 as needed, copies the data to the U disk, and then inserts the U disk into the computer to further analyze the data. The staff manually sets or modifies the safety value through the safety value setting button 15. When the received monitoring data exceeds the safety value, the alarm 17 is triggered to automatically alarm.

[0055] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. Any modification or partial replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. The integrated anchor monitoring device for bottom expansion and filling based on electromagnetic ultrasonic technology is characterized by: Including drilling, expansion and injection equipment, anchoring components and electromagnetic ultrasonic monitoring equipment; The drilling, expansion and injection integrated equipment drills an anchor hole of a certain depth on the top of the mine tunnel and connects it to the high-pressure pump station after expanding the hole. The high-pressure pump station injects high-pressure slurry into the filling area of ​​the surrounding rock around the anchor hole through the drilling, expansion and injection integrated equipment; The anchoring assembly is anchored in the anchoring hole, and an electromagnetic excitation coil and an induction receiving coil are wound around the anchoring assembly; The electromagnetic ultrasonic monitoring device is connected to the electromagnetic excitation coil and the induction receiving coil through signal wires. The electromagnetic ultrasonic monitoring device applies an AC signal to the electromagnetic excitation coil, and the electromagnetic excitation coil induces an alternating magnetic field. The induction receiving coil generates an induced voltage under the action of the alternating magnetic field and transmits it to the electromagnetic ultrasonic monitoring device. The drilling, expansion and injection equipment includes a hollow drill bit and a hole protection casing. The hollow drill bit is a conical structure with a thin front and a thick back. The rear end of the hollow drill bit is fixedly connected with the front end of the hole protection casing. The maximum diameter of the hollow drill bit is larger than the outer diameter of the hole protection casing. A plurality of funnel-shaped grouting ports that are transparent inside and outside and larger outside and smaller inside are evenly arranged on the outer circumference of the hollow drill bit and the outer circumference of the middle front side of the hole protection casing. Three knife grooves are arranged on the outer circumference of the hollow drill bit. The three knife grooves are arranged in a circumferential array. The knife groove is arranged along the generatrix direction of the hollow drill bit, and a hole-reaming blade is arranged in each knife groove. The rear end of the hole-reaming blade is hinged in the knife groove at the connection between the hollow drill bit and the hole-protecting sleeve through a pin shaft, the pin shaft is perpendicular to the center line of the hole-protecting sleeve, the diameter of the pin shaft is greater than the thickness of the hole-protecting sleeve, and the side of the pin shaft close to the center line of the hole-protecting sleeve is located in the hole-protecting sleeve and the hollow drill bit, the hole-protecting sleeve is fixed in the anchor hole, and the rear end of the hole-protecting sleeve is flush with the hole opening of the anchor hole; The anchor assembly includes an anchor rod, a gasket and a nut. The diameter of the anchor rod is the same as the inner diameter of the hole protection casing, the length of the anchor rod is greater than the length of the hole protection casing, the electromagnetic excitation coil is wound and fixed on the outer circumference of the front end of the anchor rod, the induction receiving coil is wound and fixed on the outer circumference of the rear end of the anchor rod, the outer circumference of the anchor rod is provided with an external thread, the anchor rod is anchored in the hole protection casing, the front end of the anchor rod extends into the hole protection casing and is flush with the front end of the hole protection casing, the rear end of the anchor rod extends out of the rear end of the hole protection casing, the gasket is sleeved on the rear side of the anchor rod and is in tight contact with the top of the mine tunnel, and the nut is threadedly connected to the rear side of the anchor rod and is in tight contact with the gasket; An AC signal transmission button and a safety value setting button are provided at the lower front part of the electromagnetic ultrasonic monitoring device, a display is provided at the upper front part of the electromagnetic ultrasonic monitoring device, an alarm and a USB data interface are provided at the top of the electromagnetic ultrasonic monitoring device, and the safety value setting button is connected to the alarm signal.

2. The monitoring method of the bottom expansion and filling integrated anchoring monitoring device based on electromagnetic ultrasonic technology as claimed in claim 1 is characterized by: The specific steps include: (1) Use drilling, expansion and injection equipment to drill anchor holes of a certain depth on the top of the mine tunnel; (2) Use drilling, expansion and injection equipment to expand the bottom of the anchor hole; (3) Grouting into the filling area of ​​the surrounding rock; (4) Anchor the anchor rod in the anchor hole; (5) Monitor the anchoring effect using electromagnetic ultrasonic monitoring equipment.

3. The monitoring method of the bottom expansion and filling integrated anchoring monitoring device based on electromagnetic ultrasonic technology according to claim 2 is characterized in that: Step (1) specifically comprises: using a hollow drill bit to drill to a specified depth at the top of a mine tunnel, thereby drilling an anchor hole, fixing a hole protection casing in the anchor hole, and protecting the anchor hole, so that the rear end of the hole protection casing is flush with the hole mouth of the anchor hole.

4. The monitoring method of the bottom expansion and filling integrated anchoring monitoring device based on electromagnetic ultrasonic technology according to claim 2 is characterized in that: Step (2) is specifically as follows: use a push rod with a tapered front end to push it into the hole protection casing, insert the front end of the push rod into the hollow drill bit and squeeze the three pins, so that the three reaming blades are ejected to the specified angle at the same time, and then the hollow drill bit continues to rotate, so that the three reaming blades expand the bottom of the anchor hole, so that the anchor hole is formed into an inverted cone hole with a larger inside and a smaller outside. After the hole expansion is completed, the hollow drill bit stops rotating, and the push rod is pulled out, so that the three pins are no longer squeezed, and the three reaming blades are respectively retracted into the three tool grooves.

5. The monitoring method of the bottom expansion and filling integrated anchoring monitoring device based on electromagnetic ultrasonic technology according to claim 2 is characterized in that: Step (3) is specifically as follows: the rear end of the hole protection casing is connected to the high-pressure pump station, and the high-pressure pump station pumps high-pressure slurry into the hole protection casing. The high-pressure slurry is evenly injected into the filling area of ​​the surrounding rock around the anchor hole through the hollow drill bit and the funnel-shaped grouting ports on the hole protection casing.

6. The monitoring method of the bottom expansion and filling integrated anchoring monitoring device based on electromagnetic ultrasonic technology according to claim 2 is characterized in that: Step (4) is specifically as follows: after the grouting is completed, the hole protection casing and the high-pressure pump station are separated, and the hole sealer is installed in the middle of the outer circumference of the hole protection casing to seal the gap between the anchor hole and the hole protection casing to prevent the slurry from flowing out and affecting the anchoring effect. The anchor rod is directly driven into the hole protection casing so that the front end of the anchor rod is flush with the front end of the hole protection casing, and the rear end of the anchor rod extends out of the rear end of the hole protection casing. The gasket is put on the rear side of the anchor rod and pressed into contact with the roof of the mine tunnel. The nut is threadedly connected to the rear side of the anchor rod and pressed into contact with the gasket, so that the anchor rod is firmly anchored.

7. The monitoring method of the bottom expansion and filling integrated anchoring monitoring device based on electromagnetic ultrasonic technology according to claim 2 is characterized in that: Step (5) is specifically as follows: the button for applying AC signal transmission is pressed, and the electromagnetic ultrasonic monitoring device applies AC signal to the electromagnetic excitation coil. The electromagnetic excitation coil induces an alternating magnetic field. The alternating magnetic field acts on the anchor rod, and a stress wave is generated in the anchor rod. The stress wave is reflected and refracted and then transmitted backward in the form of guided wave. The guided wave causes the spatial magnetic field to change. The induction receiving coil generates an induced voltage under the action of the alternating magnetic field, which is transmitted to the electromagnetic ultrasonic monitoring device in the form of an electrical signal. After receiving the electrical signal, the electromagnetic ultrasonic monitoring device processes it and displays the processed image through the display. At the same time, the processed image and data are stored in the storage of the electromagnetic ultrasonic monitoring device. The staff inserts the U disk into the USB data interface as needed, copies the data to the U disk, and then inserts the U disk into the computer to further analyze the data. The staff manually sets or modifies the safety value through the safety value setting button. When the received monitoring data exceeds the safety value, the alarm is triggered to automatically alarm.

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