Sealed water injection device and method for ultrasonic detection of cataclastic rock mass
By using tie rods, multiple water-filling sealing mechanisms, and borehole sealing mechanisms in fractured rock mass detection, a stable water-filling environment is created, solving the problems of borehole water leakage and probe damage, and achieving efficient and accurate ultrasonic detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JINCHUAN GROUP CO LTD
- Filing Date
- 2026-03-27
- Publication Date
- 2026-05-05
AI Technical Summary
In fractured rock mass detection, borehole water is prone to leakage, bag probes are easily damaged, detection efficiency is low, coupling effect is poor, and data distortion is caused.
It employs a pull rod, a water injection multi-seal mechanism, and a drilling sealing mechanism to form a dynamic and static dual seal. Combined with an annular inflatable sealing bladder, it prevents water leakage and ensures a stable water filling environment.
It achieves efficient wet-hole ultrasonic testing in fractured rock masses, with probes that are less prone to damage, improved testing efficiency, high data accuracy, and avoidance of signal attenuation.
Smart Images
Figure CN121978219A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of geotechnical engineering testing technology, specifically to a sealed water injection device and method for ultrasonic testing of fractured rock masses. Background Technology
[0002] In geotechnical engineering investigation, mining, tunnel construction, and other engineering fields, the integrity testing of fractured rock masses is a core aspect of engineering safety design and construction. Ultrasonic testing has become the mainstream method for rock mass integrity testing due to its ease of operation and high accuracy. Ultrasonic testing requires water as a coupling medium to efficiently transmit ultrasonic signals to the rock mass, i.e., the wet borehole testing method. However, it faces a key technical bottleneck in fractured rock mass testing: fractured rock masses have well-developed fissures, and water filling the borehole can easily seep rapidly along the fissures, making it impossible to form a stable water-filled environment, thus making the wet borehole testing method difficult to implement.
[0003] Currently, the industry generally uses the dry hole detection method with a bag-type probe as a substitute. This method requires inserting a probe with an inflatable bag into the borehole and completing a cycle of "bag filling with water - expansion and adhesion to the wall - detection - pumping out water - relocation" at each measuring point. This method has many drawbacks in practical applications: 1. Each measuring point requires repeated water injection and pumping processes. For deep hole testing, testing the entire hole section is time-consuming, which seriously affects the project progress. 2. After being filled with water, the bag repeatedly rubs against the rough borehole wall and sharp rock fragments inside the borehole, which can easily cause it to be scratched or burst, leading to interruption of the detection and high equipment maintenance costs. 3. The local sealing of the bag-type probe is easily affected by the flatness of the hole wall, resulting in unstable coupling effect, which leads to ultrasonic signal attenuation and distortion, and low reliability of detection data.
[0004] To solve the above problems, there is an urgent need to develop a sealed water injection device that can create a stable water-filled environment in boreholes in fractured rock masses. Summary of the Invention
[0005] The purpose of this invention is to provide a sealed water injection device and method for ultrasonic testing of fractured rock masses, which solves the technical problems of easy leakage of borehole water, easy damage of bag probe, low detection efficiency, and poor coupling effect leading to data distortion in ultrasonic testing of fractured rock masses.
[0006] To achieve the above objectives, the present invention provides the following technical solution: a sealing water injection device for ultrasonic testing of fractured rock mass, comprising a pull rod, an ultrasonic probe for rock mass disposed at one end of the pull rod, and a water injection multi-sealing mechanism and a borehole sealing and plugging mechanism sleeved on the outer wall of the water injection multi-sealing mechanism; the pull rod passes through the interior of the water injection multi-sealing mechanism and forms a dynamic sealing fit with the inner wall of the water injection multi-sealing mechanism, and can reciprocate along the axial direction of the water injection multi-sealing mechanism; the pull rod, the water injection multi-sealing mechanism and the borehole sealing and plugging mechanism are coaxially arranged.
[0007] Furthermore, the water injection multi-seal mechanism includes a sealing column, a tie rod channel and two water pipe channels inside the sealing column, a return water pipe inside one water pipe channel, a stop valve on the return water pipe section away from the end of the ultrasonic probe in the rock mass, a water injection pipe inside the other water pipe channel, a first multi-seal structure on the inner wall of the water pipe channel, and a second multi-seal structure on the inner wall of the tie rod channel. The tie rod channel and the two water pipe channels extend axially along the sealing column and are both through structures, with their ends penetrating the two end faces of the sealing column. The tie rod channel is coaxially arranged with the sealing column, and the two water pipe channels are symmetrically arranged along the tie rod channel. The tie rod slides in the tie rod channel and extends to both ends of the sealing column. The tie rod is tightly fitted to the inner wall of the second multi-seal structure. The return water pipe and the water injection pipe slide in the inner walls of the two water pipe channels and extend to both ends of the sealing column. The return water pipe and the water injection pipe are tightly fitted to the inner wall of the first multi-seal structure.
[0008] Furthermore, the inner sidewall of the pull rod channel is provided with a plurality of spaced second annular grooves along its length; the second multi-seal structure includes second sealing rings respectively disposed inside the plurality of second annular grooves; the plurality of second sealing rings are all sleeved on the outer wall of the pull rod and form a dynamic sealing fit with the outer wall of the pull rod.
[0009] Furthermore, the inner wall of the water pipe channel is provided with a plurality of spaced first annular grooves along its length; the first multi-seal structure includes first sealing rings respectively disposed inside the plurality of first annular grooves; the plurality of first sealing rings are all sleeved on the outer wall of the return water pipe and the injection water pipe, and form a static sealing fit with their outer walls.
[0010] Furthermore, the sealing column is made of high-strength nylon material.
[0011] Furthermore, the borehole sealing and plugging mechanism includes an annular inflatable sealing bladder, waterproof sealing linings respectively disposed on the inner and outer walls of the annular inflatable sealing bladder, and an inflation valve connected to the end of the annular inflatable sealing bladder away from the rock mass ultrasonic probe; the waterproof sealing lining located on the inner wall of the annular inflatable sealing bladder is sleeved on the outer wall of the sealing column and is tightly fitted to the outer wall of the sealing column; the waterproof sealing lining is a waterproof sealing strip wrapped around the inner or outer wall of the annular inflatable sealing bladder.
[0012] Furthermore, the annular inflatable sealing bladder is made of a composite material of polymer and metal.
[0013] Furthermore, the sealing column and the annular inflatable sealing bladder are provided with four epoxy resin fixing tapes at the end away from the ultrasonic probe of the rock mass. The sealing column and the annular inflatable sealing bladder are fixedly connected to the rock mass at the borehole opening by the four epoxy resin fixing tapes arranged in a cross pattern.
[0014] The present invention also discloses a method for using the above-mentioned sealed water injection device for ultrasonic testing of fractured rock mass, comprising the following steps: Step 1: Fix the ultrasonic probe of the rock mass to the front end of the tie rod, insert the tie rod into the tie rod channel, and position the probe on one side of the borehole opening; insert the water injection pipe and the water return pipe into the corresponding water pipe channels respectively, and achieve static sealing through multiple first sealing rings; fit the annular inflatable sealing bladder onto the outer wall of the sealing column. Step 2: Install the sealing column at the preset position at the borehole opening, and use cross-laid epoxy resin fixing tape to pre-fix the sealing column and the annular inflatable sealing bladder to the rock surface at the borehole opening; Step 3: Push the pull rod to push the ultrasonic probe of the rock mass to the bottom of the borehole; inflate the annular air-sealing bladder through the air-filling valve to make the annular air-sealing bladder expand and fit tightly against the borehole wall and the outer wall of the sealing column, forming an annular sealing strip at the borehole opening in conjunction with the waterproof sealing liner, blocking the channel for water to seep through the cracks in the borehole. Step 4: Inject clean water into the borehole through the water injection pipe. When a continuous flow of water comes out of the return pipe, it indicates that the borehole has been filled. Close the shut-off valve to maintain a stable water filling environment in the borehole. Step 5: Push or pull the tie rod to move the ultrasonic probe of the rock mass along the axis at a set interval in the water-filled borehole. Perform ultrasonic testing at each measuring point. Through the dynamic sealing cooperation of multiple second sealing rings and the tie rod, the water-filled environment in the borehole is kept intact, and the ultrasonic data acquisition of the entire borehole section is completed. Step Six: After the test is completed, open the shut-off valve to drain the water accumulated in the borehole, release the gas in the annular air-sealed bladder through the air-inflating valve, remove the epoxy resin fixing tape, and remove the device from the borehole opening.
[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The multiple dynamic and static sealing rings of the water injection multi-seal mechanism achieve gap sealing between the tie rod, the water injection and return pipe and the sealing column. Combined with the annular air-filled sealing bladder of the borehole sealing and plugging mechanism, the borehole is completely sealed. The double sealing structure completely blocks the water leakage channel in the borehole of the fractured rock mass. It can form a stable water-filled environment in the fractured rock mass with developed fractures, realize efficient wet borehole ultrasonic detection, and fill the technical gap of wet borehole detection in fractured rock mass.
[0016] 2. This invention sets the sealing structure at the borehole opening, and the rock ultrasonic probe is a non-bag type structure. During the detection process, the probe only contacts the water and does not rub against the rough borehole wall or sharp rock blocks inside the borehole. This fundamentally solves the problem that traditional bag probes are easily scratched and burst, greatly extending the service life of the equipment and significantly reducing maintenance costs.
[0017] 3. After sealing the borehole opening, ultrasonic testing of the entire borehole section can be completed with a single water injection, eliminating the need for repeated water injection and pumping at each testing point, thus improving testing efficiency.
[0018] 4. A stable water-filling environment ensures efficient and attenuation-free transmission of ultrasonic signals, avoiding signal distortion caused by unstable coupling in traditional dry hole methods, resulting in high accuracy of detection data; the water outlet status of the return water pipe can be used to intuitively judge the water injection status of the borehole, effectively avoiding the problems of insufficient or excessive water injection, further ensuring the reliability of detection data. Attached Figure Description
[0019] Figure 1 This is a schematic cross-sectional view of the sealed water injection device for ultrasonic testing of fractured rock mass according to the present invention. Figure 2 For the present invention Figure 1 A magnified schematic diagram of the partial structure at point A in the middle; Figure 3 This is a top view of the water injection multi-sealing mechanism of the present invention. Figure 4 This is a schematic diagram of the assembly structure of the drilling sealing and plugging mechanism of the present invention.
[0020] In the diagram: 1. Tie rod; 2. Rock mass ultrasonic probe; 3. Water injection multi-seal mechanism; 4. Sealing column; 5. Water pipe channel; 6. First annular groove; 7. First sealing ring; 8. Water injection pipe; 9. Return water pipe; 10. Tie rod channel; 11. Second annular groove; 12. Second sealing ring; 13. Stop valve; 14. Drill hole sealing and plugging mechanism; 15. Annular inflatable sealing bladder; 16. Waterproof sealing liner; 17. Inflation valve; 18. Epoxy resin fixing tape. Detailed Implementation
[0021] Please see Figure 1-4 A sealed water injection device for ultrasonic testing of fractured rock masses includes a pull rod 1 and an ultrasonic probe 2 for rock masses connected to one end of the pull rod 1. The pull rod 1 is made of seamless stainless steel pipe with a special surface treatment to achieve a surface roughness of [missing information]. It also includes a water-injection multi-seal mechanism 3 and a drilling sealing and plugging mechanism 14 sleeved on the outer wall of the water-injection multi-seal mechanism 3; the pull rod 1 passes through the interior of the water-injection multi-seal mechanism 3 and forms a dynamic sealing fit with the inner wall of the water-injection multi-seal mechanism 3, and can move back and forth along the axial direction of the water-injection multi-seal mechanism 3. In order to reduce frictional resistance, the surface of the pull rod 1 is coated with a silicone-based grease compatible with the material of multiple second sealing rings 12; the pull rod 1, the water-injection multi-seal mechanism 3 and the drilling sealing and plugging mechanism 14 are arranged coaxially to ensure the overall sealing performance and smooth movement of the device.
[0022] The water injection multi-seal mechanism 3 includes a sealing column 4, a tie rod channel 10 and two water pipe channels 5 inside the sealing column 4, a return water pipe 9 inside one of the water pipe channels 5, a shut-off valve 13 on the return water pipe 9 at the end away from the ultrasonic probe 2 in the rock mass, a water injection pipe 8 inside the other water pipe channel 5, a first multi-seal structure on the inner wall of the water pipe channel 5, and a second multi-seal structure on the inner wall of the tie rod channel 10. The tie rod channel 10 and the two water pipe channels 5 extend axially along the sealing column 4 and are all through structures, with their two ends penetrating the two end faces of the sealing column 4 respectively. The tie rod channel 10 is coaxially arranged with the sealing column 4, and the two water pipe channels 5 are symmetrically arranged along the tie rod channel 10. The inner walls of the tie rod channel 10 and the two water pipe channels 5 are precision machined, and the surface roughness is controlled within a certain range. Within the specified range, to ensure a sealing effect; the pull rod 1 slides within the pull rod channel 10, facilitating the pushing / pulling of the pull rod 1 to move the ultrasonic probe 2, and both ends extend to both ends of the sealing column 4. The pull rod 1 is tightly fitted to the inner wall of the second multi-layer sealing structure, ensuring that water in the borehole will not leak from the gap between the pull rod and the channel during the reciprocating movement of the pull rod 1; the return water pipe 9 and the injection water pipe 8 slide within the inner walls of the two water pipe channels 5, and both ends extend to both ends of the sealing column 4. Both the return water pipe 9 and the injection water pipe 8 are made of pressure-resistant hoses, and the appropriate pipe diameter is selected according to the borehole depth; the return water pipe 9 and the injection water pipe 8 are tightly fitted to the inner wall of the first multi-layer sealing structure to prevent water from leaking from the gap between the return water pipe 9 and the injection water pipe 8 and the water pipe channel 5; the injection water pipe 8 is used to inject water into the borehole, and the return water pipe 9 is used to provide feedback on the water injection status in the borehole. The shut-off valve 13 is installed at the end of the return water pipe 9 away from the ultrasonic probe 2 in the rock mass, and is used to control the return water flow and maintain stable water pressure in the borehole.
[0023] The inner wall of the pull rod channel 10 is provided with multiple spaced second annular grooves 11 along its length; the second multi-seal structure includes second sealing rings 12 respectively disposed inside the multiple second annular grooves 11; the multiple second sealing rings 12 are all sleeved on the outer wall of the pull rod 1 and form a dynamic sealing fit with the outer wall of the pull rod 1. The multiple second sealing rings 12 form a progressive dynamic seal, which greatly improves the sealing effect and avoids water leakage during the movement of the pull rod 1.
[0024] The inner wall of the water pipe channel 5 is provided with multiple spaced first annular grooves 6 along its length; the first multi-seal structure includes first sealing rings 7 respectively disposed inside the multiple first annular grooves 6; the multiple first sealing rings 7 are all sleeved on the outer walls of the return water pipe 9 and the injection water pipe 8, and form a static seal fit with their outer walls. The multiple first sealing rings 7 form a multiple static seal, completely preventing water from leaking from the gap between the return water pipe 9 and the injection water pipe 8 and the water pipe channel 5.
[0025] The sealing column 4 is made of high-strength nylon, which combines good mechanical strength, corrosion resistance, and wear resistance, making it suitable for complex site environments in geotechnical engineering. The second sealing ring 12 and the first sealing ring 7 are both made of nitrile rubber with a Shore hardness of 70. For applications where the diameter of the pull rod 1 is 10mm, the specifications of the second sealing ring 12 and the first sealing ring 7 are an outer diameter of 41.78mm and an inner diameter of 37.65mm. The inner diameter of the second sealing ring 12 is matched with the diameter of the pull rod 1 (10mm). This specification can provide a compression rate of 18-22% after installation, which ensures the sealing effect without generating excessive frictional resistance. The second sealing ring 12 and the first sealing ring 7 are installed in the pull rod channel 10 and the corresponding water pipe channel 5, respectively, to improve the reliability of the seal. The specifications of the second annular groove 11 and the first annular groove 6 are: a depth of 1.3 mm and a width of 2.5 mm, which match the size and compression ratio of the second sealing ring 12 and the first sealing ring 7; the waterproof sealing liner 16 is a butyl waterproof sealing strip, and the epoxy resin fixing tape 18 is a high-strength engineering grade tape.
[0026] The borehole sealing and plugging mechanism 14 includes an annular inflatable sealing bladder 15, waterproof sealing linings 16 respectively disposed on the inner and outer walls of the annular inflatable sealing bladder 15, and an inflation valve 17 connected to the end of the annular inflatable sealing bladder 15 away from the rock mass ultrasonic probe 2, used to connect to an external inflation device to realize the inflation and deflation operations of the annular inflatable sealing bladder 15. The waterproof sealing lining 16 located on the inner wall of the annular inflatable sealing bladder 15 is sleeved on the outer wall of the sealing column 4, and is made of high-molecular polymer and metal composite material, which has excellent airtightness, pressure resistance and flexibility. Before inflation, the annular inflatable sealing bladder 15 is in a flat state. After inflation, it can tightly fit the borehole wall of different diameters, adapting to borehole inspection of various diameters. The design inflation pressure of the annular inflatable sealing bladder 15 is 0.28. MPa, under this pressure it can adapt to boreholes of different diameters; and it fits tightly against the outer wall of the sealing column 4; the waterproof sealing liner 16 is a waterproof sealing strip wrapped around the inner or outer wall of the annular inflatable sealing bladder 15 to prevent water from leaking from the gap between the annular inflatable sealing bladder 15 and the sealing column 4. The waterproof sealing liner 16 on the outer wall enhances the fit between the annular inflatable sealing bladder 15 and the borehole wall, and improves the sealing effect of the borehole opening.
[0027] Four epoxy resin fixing tapes 18 are provided at the ends of the sealing column 4 and the annular inflatable sealing bladder 15 away from the ultrasonic probe 2 in the rock mass. The sealing column 4 and the annular inflatable sealing bladder 15 are fixedly connected to the rock mass at the borehole opening by the four epoxy resin fixing tapes 18 arranged in a cross pattern. This firmly fixes the sealing column 4 and the annular inflatable sealing bladder 15 to the surface of the rock mass at the borehole opening, realizes the pre-positioning of the device, prevents the device from shifting during inflation and testing, and ensures the sealing effect.
[0028] A method for using a sealed water injection device for ultrasonic testing of fractured rock mass includes the following steps: Step 1: Fix the ultrasonic probe 2 to the front end of the tie rod 1, insert the tie rod 1 into the tie rod channel 10, and position the probe 2 on one side of the borehole opening; insert the water injection pipe 8 and the return water pipe 9 into the corresponding water pipe channels 5 respectively, and achieve static sealing through multiple first sealing rings 7; fit the annular inflatable sealing bladder 15 onto the outer wall of the sealing column 4. Step 2: Install the sealing column 4 at the preset position at the borehole opening, and use the cross-laid epoxy resin fixing tape 18 to pre-fix the sealing column 4 and the annular inflatable sealing bladder 15 to the rock surface at the borehole opening. Step 3: Push the pull rod 1 to push the rock ultrasonic probe 2 to the bottom of the borehole. Push it slowly to avoid the rock ultrasonic probe 2 colliding with the borehole wall and causing damage. Inflate the annular air-sealing bladder 15 through the air-filling valve 17 to make the annular air-sealing bladder 15 expand and fit tightly against the borehole wall and the outer wall of the sealing column 4. Together with the waterproof sealing liner 16, it forms an annular sealing strip at the borehole opening, blocking the channel for water to seep through the cracks in the borehole. Step 4: Inject clean water into the borehole through the water injection pipe 8. When a continuous flow of water comes out of the return water pipe 9, it indicates that the borehole has been filled. Close the shut-off valve 13 to maintain a stable water filling environment in the borehole.
[0029] Step 5: Push or pull the tie rod 1 to move the ultrasonic probe 2 along the axis at a set interval in the water-filled borehole. Perform ultrasonic testing at each measuring point. Through the dynamic sealing cooperation between multiple second sealing rings 12 and the tie rod 1, the water-filled environment in the borehole is kept intact, and the ultrasonic data acquisition of the entire borehole section is completed.
[0030] Step 6: After the test is completed, open the shut-off valve 13 to drain the water accumulated in the borehole, release the gas in the annular air-sealed bladder 15 through the air-inflating valve 17, remove the epoxy resin fixing tape 18, and remove the device from the borehole opening.
[0031] Working process and principle: First, the ultrasonic probe 2 is fixed to the front end of the pull rod 1. The pull rod 1 is inserted into the pull rod channel 10 of the sealing column 4. The water injection pipe 8 and the return water pipe 9 are respectively inserted into the corresponding water pipe channels 5. Static sealing is achieved through multiple first sealing rings 7. The annular inflatable sealing bladder 15 is fitted onto the outer wall of the sealing column 4. Then, epoxy resin fixing tape 18 is used to pre-fix the sealing column 4 and the annular inflatable sealing bladder 15 to the surface of the borehole. Subsequently, the pull rod 1 is pushed to send the probe 2 to the bottom of the borehole. The annular inflatable sealing bladder 15 is inflated through the inflation valve 17, causing it to expand and tightly fit against the borehole wall and the outer wall of the sealing column 4. Together with the waterproof sealing liner 16, an annular sealing strip is formed at the borehole opening, blocking the water leakage channel caused by the fracture of the rock mass.
[0032] Next, clean water is injected into the borehole through the water injection pipe 8. When a continuous flow of water flows out of the return water pipe 9, it indicates that the borehole is full. The shut-off valve 13 is then closed to create a stable water-filled environment within the borehole. During testing, the pull rod 1 is pulled or pushed to move the probe 2 axially within the water-filled borehole. The second sealing ring 12 within the pull rod channel 10 forms a dynamic seal with the pull rod 1, maintaining the water-filled environment within the borehole. Ultrasonic waves are efficiently transmitted from the probe 2 to the fractured rock mass and reflected back to the probe 2 using water as the coupling medium, achieving ultrasonic data acquisition across the entire borehole section. After testing, the shut-off valve 13 is opened to drain the accumulated water, the gas inside the annular inflatable sealing bladder 15 is released, and the epoxy resin fixing tape 18 is removed, completing the device disassembly.
[0033] In summary, this invention achieves dynamic and static dual sealing of the tie rod, water injection and return pipe, and sealing column through a water injection multi-seal mechanism. Combined with the annular inflatable sealing bladder of the borehole sealing and plugging mechanism, it forms a reliable seal at the borehole opening. Ultrasonic testing of the entire borehole section can be completed with a single water injection. This solves the problems of water leakage, easy damage to traditional bag probes, and low testing efficiency in fractured rock mass testing. It has excellent sealing performance, is easy to operate, and provides accurate test data, making it suitable for ultrasonic testing needs of various fractured rock mass boreholes.
[0034] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A sealed water injection device for ultrasonic testing of fractured rock mass, comprising a pull rod (1) and an ultrasonic probe (2) for rock mass disposed at one end of the pull rod (1), characterized in that, It also includes a water injection multi-seal mechanism (3) and a drilling sealing and plugging mechanism (14) sleeved on the outer wall of the water injection multi-seal mechanism (3); the pull rod (1) passes through the interior of the water injection multi-seal mechanism (3) and forms a dynamic sealing fit with the inner wall of the water injection multi-seal mechanism (3), and can move back and forth along the axial direction of the water injection multi-seal mechanism (3); the pull rod (1), the water injection multi-seal mechanism (3) and the drilling sealing and plugging mechanism (14) are arranged coaxially.
2. The sealed water injection device for ultrasonic testing of fractured rock mass according to claim 1, characterized in that, The water injection multi-seal mechanism (3) includes a sealing column (4), a tie rod channel (10) opened inside the sealing column (4), two water pipe channels (5), a return water pipe (9) located inside one water pipe channel (5), a shut-off valve (13) located on the return water pipe (9) section and away from the end of the ultrasonic probe (2) of the rock mass, a water injection pipe (8) located inside the other water pipe channel (5), a first multi-seal structure located on the inner wall of the water pipe channel (5), and a second multi-seal structure located on the inner wall of the tie rod channel (10); the tie rod channel (10) and the two water pipe channels (5) are all extended along the axial direction of the sealing column (4) and are all through-type. The structure has two ends that pass through the two end faces of the sealing column (4); the pull rod channel (10) is coaxially arranged with the sealing column (4), and the two water pipe channels (5) are symmetrically arranged along the pull rod channel (10); the pull rod (1) is slidably engaged with the pull rod channel (10), and both ends extend to both ends of the sealing column (4); the pull rod (1) is tightly fitted with the inner wall of the second multi-seal structure; the return water pipe (9) and the injection water pipe (8) are slidably engaged with the inner walls of the two water pipe channels (5), and both ends extend to both ends of the sealing column (4); the return water pipe (9) and the injection water pipe (8) are tightly fitted with the inner wall of the first multi-seal structure.
3. The sealed water injection device for ultrasonic testing of fractured rock mass according to claim 2, characterized in that, The inner wall of the pull rod channel (10) is provided with a plurality of spaced second annular grooves (11) along its length; the second multi-seal structure includes a second sealing ring (12) respectively disposed inside the plurality of second annular grooves (11); the plurality of second sealing rings (12) are all sleeved on the outer wall of the pull rod (1) and form a dynamic sealing fit with the outer wall of the pull rod (1).
4. The sealed water injection device for ultrasonic testing of fractured rock mass according to claim 2, characterized in that, The inner wall of the water pipe channel (5) is provided with a plurality of spaced first annular grooves (6) along its length; the first multi-seal structure includes first sealing rings (7) respectively disposed inside the plurality of first annular grooves (6); the plurality of first sealing rings (7) are all sleeved on the outer wall of the return water pipe (9) and the injection water pipe (8), and form a static sealing fit with their outer walls.
5. The sealed water injection device for ultrasonic testing of fractured rock mass according to claim 2, characterized in that, The sealing column (4) is made of high-strength nylon material.
6. The sealed water injection device for ultrasonic testing of fractured rock mass according to claim 2, characterized in that, The borehole sealing and plugging mechanism (14) includes an annular inflatable sealing bladder (15), a waterproof sealing liner (16) respectively disposed on the inner wall and outer wall of the annular inflatable sealing bladder (15), and an inflation valve (17) connected to the end of the annular inflatable sealing bladder (15) away from the ultrasonic probe (2) of the rock mass; the waterproof sealing liner (16) located on the inner wall of the annular inflatable sealing bladder (15) is sleeved on the outer wall of the sealing column (4) and is tightly fitted to the outer wall of the sealing column (4); the waterproof sealing liner (16) is a waterproof sealing strip wrapped around the inner wall or outer wall of the annular inflatable sealing bladder (15).
7. The sealed water injection device for ultrasonic testing of fractured rock mass according to claim 6, characterized in that, The annular inflatable sealing bladder (15) is made of a composite material of polymer and metal.
8. The sealed water injection device for ultrasonic testing of fractured rock mass according to claim 6, characterized in that, The sealing column (4) and the annular inflatable sealing bladder (15) are provided with four epoxy resin fixing tapes (18) at the end away from the ultrasonic probe (2) of the rock mass. The sealing column (4) and the annular inflatable sealing bladder (15) are fixedly connected to the rock mass at the borehole opening by the four epoxy resin fixing tapes (18) arranged in a cross pattern.
9. A method of using a sealed water injection device for ultrasonic testing of fractured rock mass according to any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Fix the ultrasonic probe (2) of the rock mass to the front end of the tie rod (1), insert the tie rod (1) into the tie rod channel (10) so that the probe (2) is located on one side of the borehole opening; insert the water injection pipe (8) and the return water pipe (9) into the corresponding water pipe channel (5) respectively, and achieve static sealing through multiple first sealing rings (7); fit the annular air-filled sealing bladder (15) onto the outer wall of the sealing column (4); Step 2: Install the sealing column (4) at the preset position of the borehole opening, and use the epoxy resin fixing tape (18) to pre-fix the sealing column (4) and the annular inflatable sealing bladder (15) to the surface of the rock mass at the borehole opening. Step 3: Push the pull rod (1) to push the rock ultrasonic probe (2) to the bottom of the borehole; inflate the annular air-sealing bladder (15) through the air-filling valve (17) to make the annular air-filling sealing bladder (15) expand and fit tightly against the borehole wall and the outer wall of the sealing column (4), and form an annular sealing strip at the borehole opening with the waterproof sealing liner (16) to block the channel for water to seep through the cracks in the borehole; Step 4: Inject clean water into the borehole through the water injection pipe (8). When a continuous flow of water comes out of the return pipe (9), it indicates that the borehole has been filled. Close the shut-off valve (13) to keep the water filling environment in the borehole stable. Step 5: Push or pull the lever (1) to move the rock mass ultrasonic probe (2) along the axis at a set interval in the water-filled borehole. Perform ultrasonic testing at each measuring point. Through the dynamic sealing cooperation between multiple second sealing rings (12) and the lever (1), the water-filled environment in the borehole is kept intact, and the ultrasonic data acquisition of the entire borehole section is completed. Step 6: After the test is completed, open the shut-off valve (13) to drain the water in the borehole, release the gas in the annular air-sealed bladder (15) through the air-filling valve (17), remove the epoxy resin fixing tape (18), and remove the device from the borehole opening.