A tunnel excavation water inrush visualization test device and test method

Abstract

The present invention discloses a tunnel excavation water inrush visualization test device and test method, belonging to the field of rock mechanics testing technology. The test device of the present invention includes a stress loading structure and a water pressure loading structure arranged at corresponding positions of a tunnel specimen containing a blind hole, a sealing structure that cooperates with the end face of the blind hole in a sealing manner, and a drilling structure for excavating water inrush from the tunnel specimen. The drilling structure includes a movable drill bit with a variable drill bit diameter and a camera structure movably mounted on the outside of the drilling structure. By controlling each movable drill bit, the present invention enables coordinated drilling and visualization operations, while simultaneously monitoring damage to the tunnel inner wall and the tunnel face, more comprehensively reflecting the working behavior and damage mechanism of tunnel excavation water inrush.

Description

Technical Field

[0001] The invention belongs to the technical field of rock mechanics testing, and in particular relates to a tunnel excavation water inrush visualization testing device and a testing method. Background Art

[0002] Understanding the hydraulic coupling damage mechanism of water inrush during tunnel excavation will provide important guidance for both understanding the damage laws of tunnel water inrush and ensuring safe tunnel construction.

[0003] On-site observation inside the tunnel is the most direct means of obtaining the tunnel water inrush damage mechanism. However, on-site observation is greatly affected by actual uncontrollable factors, and there is a great potential threat to the lives of researchers. Indoor experimental research, as an alternative, has the advantages of relatively convenient operation, high repeatability, controllable influencing factors, and relatively small threat to the lives of experimental researchers. However, there are certain deficiencies in the current test devices and test methods for tunnel excavation water inrush. For example, patent CN112414915B discloses a test system and method for simulating tunnel excavation seepage changes under complex geological conditions, which can realize the changes in the groundwater seepage field in the impermeable rock mass under the action of excavation disturbance and high-pressure seepage. However, this technology cannot realize the visualization of the internal damage of the tunnel under the action of stress-water pressure during the tunnel excavation process; patent CN111653183A discloses a visualization system for simulating fluid-solid coupling tunnel excavation, which realizes the fluid-solid coupling tunnel excavation. Visual simulation detection of excavation and seepage migration process. However, the focus of tunnel excavation water inrush is mainly on tunnel excavation stability, but this technology does not mention how to monitor and characterize the damage process of tunnel excavation water inrush; Patent CN114001994B discloses a tunnel water and mud inrush model test device and method, which realizes the problem of conducting physical research and testing on the tunnel water and mud inrush process through model testing. However, this technology uses a punching airbag as a device for applying water pressure in the tunnel. In fact, the internal water pressure will cause seepage when fracturing the tunnel. Obviously, the action mechanism of the punching airbag is inconsistent with the actual situation.

[0004] The existing technology has a technical problem that the drilling structure and visualization cannot be coordinated. Patent CN202990883U discloses a drill bit and a drilling device. The drill bit can be rotated to realize the detachable function of the drilling device inside the drilling equipment, and the drilling rod and the drill bit are separated by the outer shell. However, the technical effect of the drill bit and the camera device drilling and shooting at the same time cannot be achieved; Patent CN217354272U discloses a front-end opening and closing drilling machine, which realizes that the camera structure can be movably installed on the drilling structure. However, the drill bit needs to ensure a certain rigidity during drilling and is generally made solid. If it is hinged, it will inevitably lack rigidity, resulting in large deformation during the drilling process and easy damage, thereby damaging the camera; the high-speed drilling of the drill bit will inevitably cause uncoordinated deformation at the hinge, thereby reducing the life of the drill bit; CN206070622U discloses a culvert dredging robot based on high-pressure water drive. The camera is arranged behind the crushing impeller, but the crushing impeller causes a certain degree of obstruction to the camera shooting. Summary of the Invention

[0005] In response to the problem that the drilling structure and visualization in the existing technology cannot be coordinated, the present invention proposes a tunnel excavation water inrush visualization test device, which can realize real-time visualization of damage to the tunnel inner wall and the tunnel face. Another purpose of the present invention is to propose a test method for the tunnel excavation water inrush visualization test device.

[0006] To achieve the above objectives, the present invention adopts the following technical solutions: a tunnel excavation water inrush visualization test device, comprising a tunnel specimen, the tunnel specimen being provided with a blind hole, a data acquisition system connected to an external computer, and a stress loading structure arranged on the top, left, and right sides of the tunnel specimen; further comprising a sealing structure sealed with the end face of the blind hole, a water pressure loading structure for applying internal water pressure to the blind hole through the sealing structure, a drilling structure for excavating the tunnel specimen, and a camera structure movably sleeved on the outside of the drilling structure; the drilling structure comprising a drill bit component, a connecting component, and a power drive component, the drill bit component being arranged at the power output end of the power drive component through the connecting component, and the power drive component driving the drill bit component to rotate through the connecting component; the drill bit component comprising a fixed drill bit, a plurality of drill bit slots for accommodating a plurality of movable drill bits being provided at the front end of the fixed drill bit, and the power drive component controlling each movable drill bit to be in a working state or a storage state respectively through the connecting component.

[0007] Furthermore, the movable drill bit includes a horizontal section, one end of which is rotatably connected to the inner wall of the drill bit slot.

[0008] 7. The swiftly and minutely adjusting device for a wood-planer working table as claimed in claim 1, wherein said linking rod and said adjusting base are pivotally connected to each other with a bolt, and said bolt has a round shank to contact with said linking rod. said bolt has a round shank to contact with said linking rod. said bolt has a round shank to contact with said linking rod.

[0009] Furthermore, a drill bit is provided in the clamping strip, and the clamping strip on the adjusting rod is pushed to move to the outside of the movable drill bit, and the drill bit extends from the inside of the clamping strip, thereby realizing a variable drill bit diameter.

[0010] Furthermore, the camera structure includes a camera bracket, which adopts a cylindrical frame structure. The cylindrical frame structure includes several circular rings and several straight rods connecting the circular rings; the camera structure also includes a camera base arranged on the camera bracket and a camera installed on the camera base.

[0011] Furthermore, the water pressure loading structure includes a water tank, a water outlet is provided on one side of the water tank, and a bayonet with an internal thread is provided on the other side of the water tank. A piston is provided in the water tank, and the piston and the water tank form a closed water storage chamber. A transmission is provided on the side of the piston close to the bayonet, and a rotor is provided in the transmission, and the rotor slides on the inner wall of the transmission. The rotor is fixedly connected to a water pressure loading transmission shaft, one end of the water pressure loading transmission shaft extends into the opening of the transmission, and the outer middle section of the water pressure loading transmission shaft is provided with an external thread adapted to the internal thread, and the other end of the water pressure loading transmission shaft is connected to the output end of the motor; a reversing device is provided on one side of the water outlet, and the reversing device is respectively connected to the water inlet pipe and the water outlet pipe, and the water inlet pipe is connected to the water tank, and an inlet pipe valve is provided at the connection between the reversing device and the water inlet pipe, and an outlet pipe valve is provided at the connection between the reversing device and the water outlet pipe; the water pressure loading structure also includes a water pressure loading motor switch for controlling the direction of the water pressure loading motor.

[0012] A test method adopts the above-mentioned tunnel excavation water inrush visualization test device, comprising the following steps: S1, applying initial internal water pressure: closing the water outlet valve and opening the water inlet valve, turning on the water pressure loading motor switch to reverse, so that the water tank is filled with water, and turning off the water pressure loading motor switch after it is full; S2, applying confining pressure: applying pressure to the pressure plate to make the confining pressure value of the tunnel sample reach a preset value; S3, applying test internal water pressure: turning on the water pressure loading motor switch to rotate forward to make the internal water pressure value in the blind hole reach a predetermined internal water pressure value, turning off the water pressure loading motor switch to maintain a constant internal water pressure value; S4, drilling and excavation: controlling all movable drill bits to be in a working state, starting the drill motor, moving the drilling trolley to perform drilling and excavation, and turning on the camera to shoot the inner wall of the tunnel; S5, shooting the tunnel face: controlling some movable drill bits to be in a storage state, and shooting the tunnel face; S6, repeating S4 to S5 until the tunnel is damaged, turning off the drill motor, and ending the test.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The present invention provides a blind hole on one side of the tunnel specimen, stably applies high internal water pressure to the blind hole through a hydraulic loading structure, and seals the water-bursting blind hole with a capping structure, thereby achieving the dual functions of hydraulic loading and sealing, and is used to simulate the potential high-pressure water storage area in a real tunnel project. The hydraulic loading structure of the present invention integrates water storage and water delivery, is simple and convenient to use, and the capping structure can achieve a constant internal water pressure setting for the water-bursting blind hole.

[0015] (2) The technical deficiency that the existing drilling structure and the visualization structure cannot cooperate is solved. The camera structure of the camera cylindrical frame structure is movably mounted on the outside of the drilling structure. The drilling structure of the present invention can control each movable drill bit to be in a storage state or a working state respectively, and can realize the real-time visualization of the damage to the inner wall and the face of the tunnel while the tunnel is being excavated; through the L-shaped movable drill bit and the spring shaft, the drill bit can be replaced without changing its stiffness, which does not affect the service life of the drill bit and does not cause the uncoordinated deformation of the drill bit during high-speed drilling. The collaborative working function of the drilling structure and the camera structure is realized, and the working state and damage mechanism of water inrush during tunnel drilling are more comprehensively reflected. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic axonometric diagram of the structure of the test device of the present invention;

[0017] Figure 2 It is a schematic front view of the structure of the test device of the present invention;

[0018] Figure 3 It is a schematic rear view of the structure of the test device of the present invention;

[0019] Figure 4A schematic top view of the structure of the test device of the present invention;

[0020] Figure 5 It is a schematic axonometric diagram of the structure of the drilling structure of the present invention;

[0021] Figure 6 A partial 1 / 16 cutaway axonometric view of the drilling structure of the present invention;

[0022] Figure 7 This is a schematic cross-sectional view of the structure of the clamping drill bit of the present invention;

[0023] Figure 8 A schematic cross-sectional view of the structure of the movable drill bit of the present invention;

[0024] Figure 9 This is a schematic front view of the structure of all movable drill bits in the present invention in a working state;

[0025] Figure 10 This is a schematic axonometric view of the structure of a portion of the movable drill bit of the present invention in a stored state;

[0026] Figure 11 This is a schematic front view of the structure of a portion of the movable drill bit of the present invention in a stored state;

[0027] Figure 12 It is a schematic axonometric diagram of the structure of the camera structure of the present invention;

[0028] Figure 13 It is a schematic structural assembly diagram of the imaging structure and the drilling structure of the present invention;

[0029] Figure 14 It is a schematic axonometric diagram of the structure of the water pressure loading structure of the present invention;

[0030] Figure 15 A schematic top view of the hydraulic loading structure of the present invention;

[0031] Figure 16 A schematic cross-sectional view of a local structure of the hydraulic loading structure of the present invention;

[0032] Figure 17 This is a schematic assembly diagram of the cover structure of the present invention;

[0033] Among them, 1 is the tunnel specimen, 2 is the pressure plate, 3 is the force transmission shaft, 4 is the stress loading platform, 5 is the movable drill bit, 6 is the fixed drill bit, 7 is the camera bracket, 8 is the adjustment rod, 9 is the adjustment head, 10 is the camera trolley, 11 is the camera trolley wheel, 12 is the bearing, 13 is the drill bit rotation shaft, 14 is the drill bit motor, 15 is the drilling trolley, 16 is the drilling trolley wheel, 17 is the water pipe, 18 is the water inlet pipe, 19 is the water tank, 20 is the reversing device, 21 is the water storage tank, 22 is the water pressure loading transmission shaft, 23 is the water pressure loading motor, 24 is the motor sliding frame, 25 is the motor slide, 26 is the water pressure loading motor switch, 27 is the water pressure loading bottom plate, 28 is the water pressure gauge, 29 is the water inlet valve, 3 0 is the water supply valve, 31 is the bearing bracket, 33 is the camera, 34 is the camera base, 35 is the stainless steel sealing disk, 36 is the sealing bolt, 37 is the external thread, 38 is the water port, 39 is the water storage chamber, 40 is the piston, 41 is the actuator, 42 is the sliding cavity, 43 is the internal thread, 44 is the rotor, 45 is the bolt hole on the sample surface, 46 is the rubber bolt hole, 47 is the stainless steel sealing disk bolt hole, 48 is the stainless steel sealing disk water pressure hole, 49 is the rubber surface water pressure hole, 50 is the blind hole, 51 is the adjusting rod positioning bolt, 52 is the adjusting head groove, 53 is the drill bit slot, 54 is the clamping strip, 55 is the spring shaft, 56 is the smooth spline curve profile, 57 is rubber, and 58 is the clamping strip drill bit. DETAILED DESCRIPTION

[0034] The present invention is further described below with reference to the accompanying drawings. In the description of the present invention, the terms "front," "rear," "left," "right," "up," "down," "vertical," "horizontal," "high," "low," "inside," "outside," and the like, indicating directions or positions, are based on the directions or positions shown in the accompanying drawings and are intended solely to facilitate description and simplify the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific direction. Therefore, they should not be construed as limiting the scope of protection of the present invention.

[0035] The present invention provides a tunnel excavation water inrush visualization test device. Figures 1 to 4 It is the overall structure of the present invention, from Figures 1 to 4 It can be seen that it includes a tunnel sample 1, which is provided with a blind hole 50, a data acquisition system connected to an external computer, and a stress loading structure arranged on the top, left and right sides of the tunnel sample 1; it also includes a sealing structure that seals with the end face of the blind hole, a water pressure loading structure that applies internal water pressure to the blind hole through the sealing structure, a drilling structure for excavating water bursts in the tunnel sample, and a camera structure movably mounted on the outside of the drilling structure.

[0036] Preferably, the tunnel sample 1 is in the shape of a cube, cut from sandstone or marble, and a blind hole 50 is opened on the back of the tunnel sample 1 to simulate a potential high-pressure water storage area in a real tunnel project.

[0037] The stress loading structure includes a pressure plate 2 and a force transmission shaft 3 mounted on the pressure plate 2. The tunnel specimen 1 is located at the center of the stress loading platform 4. Pressure plates 2 are mounted above, to the left, and to the right of the tunnel specimen. Confining pressure is applied to the tunnel specimen 1 via a force transmission shaft 31 mounted on the pressure plate 2.

[0038] like Figure 5 As shown, the drilling structure of the present invention includes a drill bit component, a connecting component and a power drive component. The drill bit component is arranged at the power output end of the power drive component through the connecting component, and the power drive part drives the drill bit component to rotate through the connecting component; the drill bit component includes a fixed drill bit 6, and one end of the fixed drill bit 6 is provided with a plurality of drill bit slots 53 for accommodating a plurality of movable drill bits 6, and the power drive component controls each movable drill bit to be in a working state or a storage state respectively through the connecting component.

[0039] The tunnel face refers to the working surface where tunnel excavation is continuously advancing. Because all active drill bits are in operation, some degree of damage to the tunnel face could obstruct filming. By individually controlling the active drill bits to extend or retract from their slots, that is, during drilling, the partially obstructed active drill bits can be retracted into their slots, allowing a camera structure mounted outside the drilling structure to capture the tunnel face.

[0040] Preferably, the movable drill bit 5 includes a vertical section and a horizontal section. The outer wall of the vertical section serves as the excavation working surface, and one end of the horizontal section is movably connected to the inner wall of the drill bit slot 53. The movable drill bit is L-shaped. Compared with the "I"-shaped telescopic rod drill bit, the L-shaped movable drill bit can hide the horizontal section inside the fixed drill bit. This is because the characteristics of drilling require that the outer end of the vertical section of the movable drill bit be flush with the outer end of the fixed drill bit, while the "I"-shaped rotating shaft is exposed to the outside and is easily damaged by wear. Adding a hydraulic telescopic device to realize the operation or storage of the drill bit requires increasing the layout space of the movable drill bit inside the fixed drill bit, resulting in a reduction in the rigidity of the fixed drill bit. At the same time, the violent disturbance of the hydraulic rod during rotation will cause the automatic telescopic device to fail, affecting its service life.

[0041] like Figure 6As shown, the connecting component includes a drill bit rotating shaft 13 connecting the power drive component and the fixed drill bit 6; the connecting component also includes a plurality of movable drill bit connecting components corresponding to the plurality of movable drill bits 5, and the movable drill bit connecting component includes an adjusting rotary head 9 fixedly sleeved on the outside of the drill bit rotating shaft 13, and an adjusting rod 8 respectively connecting the adjusting rotary head 9 and the fixed drill bit 6; an adjusting rotary head groove 52 is provided on the end surface of the adjusting rotary head 9 for the rear end of the adjusting rod 8 to extend into, and the adjusting rotary head groove 52 is aligned with the side of the corresponding adjusting rotary head 9 The bolt holes opened circumferentially along the wall are connected, and the adjusting rod positioning bolts 51 inserted into the bolt holes position the adjusting rod 8. The end surface of the fixed drill bit 6 has a drill groove, and the front end of the adjusting rod 8 extends into the drill groove and then into the drill groove 53 connected to the corresponding drill groove. The front end of the adjusting rod 8 is provided with a clamping strip 54 that abuts the bottom of the horizontal section. Pushing the adjusting rod 8 drives the clamping strip 54 to move in the drill groove 53, lifting the horizontal section of the movable drill bit 5, so that the vertical section of the movable drill bit 5 extends out of the drill groove, and the movable drill bit is transformed from a storage state to an operating state. Preferably, the horizontal section of the movable drill bit is rotatably connected to the inner wall of the drill groove by a spring shaft 55, so that the horizontal section can rotate around the spring shaft 55 within the drill groove.

[0042] Since a variable drill bit diameter is required during the drilling process, a drill bit 58 is provided in the clamping strip of the present invention. Figure 7 As shown, the clamping strip on the adjusting rod is pushed to move to the outside of the movable drill bit, and the clamping strip drill bit 58 extends from the inside of the clamping strip, thereby achieving a variable drill bit diameter.

[0043] The L-shaped movable drill bit can be placed in storage or working state by moving the adjustment rod and rotating the spring shaft. Figure 8 This is a schematic cross-sectional view of the structure of the movable drill bit, in which: Figure 8 (a) shows the movable drill bit in the stowed state. The adjusting rod positioning bolt is loosened, and the adjusting rod 8 is pushed to move the clamping bar 54 away from the front end of the drill bit slot. The movable drill bit 5 is stowed inside the drill bit slot 53, with the vertical section not extending out of the slot. The spring shaft 55 is in its natural state. Figure 8(b) is a diagram of the movable drill bit in the working state. The horizontal section of the movable drill bit 5 is lifted up by the action of the adjusting rod, and the spring shaft 55 is subjected to torque and has elastic force. The vertical section extends out of the slot, and the adjusting rod positioning bolt 51 is tightened, and the movable drill bit 5 is exposed, which can increase the drilling radius, that is, increase the radius of the face. When the clamping strip 54 moves away from the front end of the drill bit slot to the bottom of the spring shaft, the elastic force of the spring shaft 55 is released, and the horizontal section will fall, storing the movable drill bit 5 inside the drill bit slot 53. The camera bracket 7 moves outside the fixed drill bit 6, and the camera 33 located at the front end of the camera bracket can shoot the face situation. A smooth spline curve profile 56 is provided at the bottom of the horizontal section where the movable drill bit 5 contacts the clamping strip 54, so that the clamping strip 54 can move more conveniently and smoothly along the smooth spline curve profile 56. As a specific embodiment, the fixed drill bit is provided with eight movable drill bits, Figure 9 All the active drill bits are in working state, that is, the eight fixed drill bits are in working state, in order to achieve the technical effect of drilling and shooting at the same time with the drilling structure and the camera structure, such as Figures 10 and 11 As shown, some of the movable drill bits are controlled to be in the storage state, that is, four movable drill bits are controlled to be in the storage state and the other four movable drill bits are controlled to be in the working state.

[0044] In the drilling structure, the power drive component includes a drill motor 14 for rotating the drill bit component, that is, the drill motor 14 is connected and driven to the fixed drill bit 6 through the drill bit rotating shaft 13, and the movable drill bit 5 rotates as the fixed drill bit 6 rotates. The power drive component also includes an adjusting rod power drive component that pushes the adjusting rod to move between the adjusting rotary head groove and the drill bit groove, and also includes a camera trolley power drive component that pushes the camera trolley to move, and also includes a drilling trolley power drive component that moves the drilling trolley; the drilling structure also includes a drill motor 14 installed on the drill trolley 15, and a drilling trolley wheel 16 is provided at the bottom of the drill trolley 15, and the position of the fixed drill bit 6 is moved by the drilling trolley wheel 16; the connecting component also includes a bearing 12 installed on the bearing bracket 31, and the rotating shaft 13 passes through the two ends of the bearing 12 and is respectively connected to the drill motor 14 and the adjusting rotary head 9.

[0045] like Figure 12 As shown, the camera structure includes a camera bracket 7, which adopts a cylindrical frame structure. The cylindrical frame structure includes a plurality of rings and a plurality of straight rods connecting the rings. The camera structure also includes a camera base 34 provided on the camera bracket 7 and a camera 33 installed on the camera base 34. The camera bracket 7 is installed on a camera trolley 10, which is provided with a camera trolley wheel 11. The position of the camera is moved by the camera trolley wheel. Figure 13As shown, the inner diameter of the camera bracket 7 is slightly larger than the diameter of the drill bit assembly, allowing the drill bit assembly to pass through the camera bracket 7, keeping part of the active drill bit in a stowed state. This allows the camera bracket 7 to be moved outside the drill bit assembly to the position of the active drill bit 5, allowing the camera at the front end of the camera bracket to capture the tunnel face and, at the same time, capture damage to the tunnel inner wall during drilling. For tunnel excavation water inrush damage testing, the tunnel face alone does not necessarily suffer damage during drilling; damage can also occur to the tunnel inner wall beyond the tunnel face. The present invention is designed to have a movable drill bit in either a stowed or working state. If the movable drill bit cannot be stowed and the drill bit diameter is approximately equal to the tunnel inner diameter, then the camera structure can be installed at the front end or inside the drill bit. However, if it is installed at the front end, it cannot capture damage to the tunnel inner wall other than the face, while if it is installed inside, it places high demands on the drill bit's rigidity. Furthermore, each movable drill bit can be controlled to be in either a stowed or working state, allowing drilling and filming to proceed simultaneously. If all movable drill bits are in a working state, the tunnel inner diameter is larger than the outer diameter of the camera structure, allowing the camera on the camera bracket to pass through the tunnel interior. If all movable drill bits are in a stowed state, the camera bracket can pass through any position outside the drilling structure. If some movable drill bits are in a working state and some are in a stowed state, the active drill bits can be prevented from obstructing the face during drilling, facilitating the camera's filming of the face. Therefore, through the synergistic action of the drilling structure and the camera structure, tunnel drilling and visualization collaborative operations can be achieved. Compared with previous technologies, the drilling of the present invention realizes the active and variable drilling characteristics and realizes the coordinated advancement with the camera. It can simultaneously monitor the water inrush damage of the tunnel inner wall and the heading face, and more comprehensively reflect the working state and damage mechanism of water inrush during tunnel drilling.

[0046] The present invention connects a plurality of circular rings through straight rods to form a camera bracket with a cylindrical frame structure. On the one hand, a camera base 34 can be installed on the cylindrical frame structure, and a camera 33 can be installed on the camera base; on the other hand, the cylindrical frame structure can be mounted on the outside of the drilling structure, that is, the drilling structure passes through the inside of the camera structure. The size of the camera 33 is smaller than the camera base 34. On the one hand, the camera 33 is fixed on the camera base 34, and on the other hand, it is convenient to install a transparent protective cover on the camera 33. The transparent protective cover can be mounted on the camera base 34 to protect the camera 33. Preferably, several cameras 33 are installed on the circumference of the camera bracket to monitor the damage of the inner wall of the tunnel, and several cameras 33 are installed at the front end of the camera bracket to monitor the damage of the face. There are multiple camera bases 34 and cameras 33 respectively. As a specific embodiment, as Figure 12As shown, four cameras 33 are mounted on the front end of the camera bracket, with eight cameras 33 mounted at the intersection of the ring and the straight rod. The camera base 34 is a cylindrical structure. The camera bracket can be moved on wheels outside the drilling structure, allowing for flexible adjustment of the camera position during excavation to monitor the extent of water inrush damage in the tunnel. Compared to existing technologies, the present invention achieves real-time visualization of the tunnel excavation process, capturing real-time footage as the excavation progresses while working in conjunction with the drilling structure.

[0047] like Figures 14 to 16As shown, the water pressure loading structure includes a water tank 21, one side of the water tank 21 is provided with a water port 38, the other side of the water tank 21 is provided with a bayonet with an internal thread 43, a piston 40 is provided in the water storage cylinder 21, the piston 40 and the water tank 21 form a closed water storage chamber 39, the piston 40 is provided with a transmission 41 on the side close to the bayonet, the transmission 41 is provided with a rotor 44, the rotor 44 slides on the inner wall of the transmission 41, the rotor 44 is fixedly connected to the water pressure loading transmission shaft 22, one end of the water pressure loading transmission shaft 22 extends into the opening of the transmission 41, the water The hydraulic loading drive shaft 22 has an external thread 37 mateable with the internal thread in its middle section. The other end of the hydraulic loading drive shaft 22 is connected to the output end of the hydraulic loading motor 23. A reversing device 20 is provided on one side of the water inlet 38. The reversing device 20 is connected to the water inlet pipe 18 and the water outlet pipe 17, respectively. The water inlet pipe 18 is in communication with the water tank 19. A water inlet valve 29 is provided at the connection between the reversing device 20 and the water inlet pipe 18, and a water outlet valve 30 is provided at the connection between the reversing device 20 and the water outlet pipe 17. The hydraulic loading structure also includes a hydraulic loading motor switch 26 for controlling the direction of the hydraulic loading motor 23. In the hydraulic loading structure, the hydraulic loading motor 23 is mounted on a motor chute 25 via a motor sliding carriage 24. The motor chute 25 and the water tank 14 are both mounted on the hydraulic loading base plate 27. To allow the rotor to slide on the inner wall of the actuator, a sliding cavity 44 filled with lubricating oil is preferably provided between the rotor and the inner wall of the actuator. When the rotor rotates forward or backward, because the sliding cavity between the rotor and the inner wall of the actuator is filled with lubricating oil, the rotor's rotation does not drive the actuator's rotation. Specifically, the piston, fixed to the actuator, does not rotate, but moves forward or backward with the rotor, ensuring the stability of the piston's movement while maintaining the seal within the water storage chamber 39. While the prior art uses high-pressure gas to compress the piston, the present invention converts motor rotation into straight piston movement, achieving stable water pressure loading. Compared to prior art, the hydraulic loading device of the present invention offers the advantages of stable water pressure output and high hydraulic loading values. Furthermore, the hydraulic loading structure of the present invention integrates water storage and water delivery, making it convenient and fast to use. By providing a driver between the piston and the hydraulic loading drive shaft bracket, the present invention achieves both detachable and assemblable operation of the hydraulic loading structure. This separates the movement of the piston and the hydraulic loading drive shaft while simultaneously connecting them together, facilitating assembly, mass production, and maintenance. The present invention employs a design in which lubricating oil is placed within the sliding cavity, resolving the problem of excessive travel caused by conventional threaded sleeves, which reduces the effective volume of the water storage chamber.

[0048] Water pressure is pumped into the blind hole 50 through the water pipe 17 to achieve water pressure loading. The data acquisition system includes a water pressure gauge 28 installed on the water pipe. By connecting to a computer system, the water pressure inside the sample blind hole 50 can be monitored in real time for adjustment. The water inlet pipe 18 allows water to be filled from the water tank 19 into the water storage tank 21.

[0049] like Figure 17 As shown, as a specific embodiment, the present invention implements a sealing cover structure for blind hole end face sealing, including a stainless steel sealing disk 35, a rubber 57, and a sealing bolt 36; four specimen surface bolt holes 45 are opened on the blind hole surface of the tunnel specimen 1, four rubber bolt holes 46 are opened on the rubber 57, and four stainless steel sealing disk bolt holes 47 are opened on the stainless steel sealing disk 35. Among them, each specimen surface bolt hole 45 and rubber bolt hole 46 corresponds one-to-one with the stainless steel sealing disk bolt hole 47. In addition, a stainless steel sealing disk water pressure hole 48 is opened on the stainless steel sealing disk 35, and a rubber surface water pressure hole 49 is opened on the rubber 57 to facilitate the passage of the water pipe 17. It should be noted that the junction between the water pipe 17 and the stainless steel sealing disk water pressure hole 48 and the rubber surface water pressure hole 49 should be wrapped with a water stop tape in the circumferential direction of the water pipe 17. At the same time, after the water pipe 17 is passed through, the surface of the water stop tape should be sprayed with epoxy resin and air-dried to solidify to prevent water leakage. Compared with previous technologies, the sealing cover structure of the present invention can coordinate the dual functions of sealing and water pressure loading.

[0050] The data acquisition system of the present invention includes a stress sensor mounted on the pressure plate 2 and a water pressure gauge 28 mounted on the water pipe 27 for monitoring the water pressure within the blind hole. The present invention also includes a computer connected to the data acquisition system and the camera. The computer is configured to obtain the confining pressure of the tunnel sample and the internal water pressure within the blind hole from the data acquisition system, and to capture tunnel damage images captured by the micro-camera. The captured data and images are then used to analyze the tunnel excavation water inrush damage process.

[0051] A test method, using the above-mentioned tunnel excavation water inrush visualization test device, includes the following steps: S1, applying initial internal water pressure: closing the water outlet valve and opening the water inlet valve, turning on the water pressure loading motor switch to reverse, so that the water storage tank 21 is filled with water, and turning off the water pressure loading motor switch after it is full; S2, applying confining pressure: applying pressure to the pressure plate to make the confining pressure value of the tunnel sample reach a preset value; S3, applying test internal water pressure: turning on the water pressure loading motor switch to rotate forward to make the internal water pressure value in the blind hole reach a predetermined internal water pressure value, turning off the water pressure loading motor switch to maintain a constant internal water pressure value; S4, drilling and excavation: controlling all movable drill bits to be in a working state, starting the drill bit motor, moving the drilling trolley to perform drilling and excavation, and turning on the camera to shoot the inner wall of the tunnel; S5, shooting the tunnel face: controlling some movable drill bits to be in a storage state, and shooting the tunnel face; S6, repeating S4 to S5 until the tunnel is damaged, turning off the drill bit motor, and ending the test.

[0052] The test method for applying the initial internal water pressure in S1 also includes: S11, closing the water outlet valve 30 and opening the water inlet valve 29, starting the water pressure loading motor switch 26 to rotate forward, driving the piston 40 to move outward, so that the water in the water tank 19 is pressed into the water storage chamber 39 under the action of atmospheric pressure, and when the motor sliding frame 24 moves to the limit of the motor slide 25, it indicates that the interior of the water tank 21 is full of water; S12, closing the water inlet valve 29 and opening the water outlet valve 30, starting the water pressure loading motor switch 26 to rotate forward, driving the piston 40 to move inward, so that the water inside the water storage chamber 39 enters the interior of the blind hole 50, and the internal water pressure value in the blind hole can be read and adjusted in real time through the water pressure gauge 28.

[0053] The S5 test method for photographing the tunnel face also includes real-time slag removal of tunnel slag through an external slag suction device to facilitate photography.

[0054] It should be noted that during the above-mentioned S4 test, the camera car can move according to the real-time damage situation of the tunnel so as to capture the real-time damage characteristics of the tunnel and effectively complete the shooting work.

[0055] The test method of the present invention also includes preparatory work before the test, specifically including: selecting marble or sandstone as the test material of the tunnel sample 1, cutting the test material into a cube shape with a cutting machine, and drilling a sample blind hole 50 of a certain depth behind the tunnel sample; placing the tunnel sample 1 at the center of the stress loading platform 4; and Figure 1Install the water pressure loading structure and the sealing structure, wrap the surface of the water pipe 17 with a water stop, and pass through the water pressure hole 48 of the stainless steel sealing plate and the water pressure hole 49 on the rubber surface; the stainless steel sealing plate 35 and the rubber 57 seal the blind hole 50 of the sample, and the sealing bolt 36 passes through the bolt hole 47 of the stainless steel sealing plate, the rubber bolt hole 46, and the bolt hole 45 on the sample surface in sequence and is tightened to fix the sealing structure to the tunnel sample. Epoxy resin is injected into the joint of the water pipe 17 and the water pressure hole 48 of the stainless steel sealing plate and cured to achieve sealing; the drilling structure and the camera structure are arranged according to Figure 13 The camera 33 is connected to an external computer and debugged.

[0056] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A tunnel excavation water inrush visualization test device, comprising a tunnel specimen provided with a blind hole, and a data acquisition system connected to an external computer, characterized in that: The invention also includes a stress loading structure arranged on the top, left and right sides of the tunnel specimen; a sealing structure that cooperates with the end face of the blind hole in a sealing manner, a water pressure loading structure that applies internal water pressure to the blind hole through the sealing structure, a drilling structure for excavating the tunnel specimen, and a camera structure that is movably sleeved on the outside of the drilling structure; the drilling structure includes a drill bit component, a connecting component and a power drive component, the drill bit component is arranged at the power output end of the power drive component through the connecting component, and the power drive component drives the drill bit component to rotate through the connecting component; the drill bit component includes a fixed drill bit, and the front end of the fixed drill bit is provided with multiple A drill slot for accommodating multiple movable drill bits, and the power drive component controls each movable drill bit to be in a working state or a storage state through a connecting component; the camera structure includes a camera bracket, and the camera bracket adopts a cylindrical frame structure, and the cylindrical frame structure includes a plurality of rings and a plurality of straight rods connecting the rings; the camera structure also includes a camera base arranged on the camera bracket and a camera installed on the camera base; the camera bracket is installed on a camera trolley, and the camera trolley is provided with a camera trolley wheel, and the position of the camera is moved by the camera trolley wheel; the movable drill bit includes a vertical section and a horizontal section, and the camera bracket adopts a cylindrical frame structure, and the cylindrical frame structure includes a plurality of rings and a plurality of straight rods connecting the rings; the camera structure also includes a camera base arranged on the camera bracket and a camera installed on the camera base; the camera bracket is installed on the camera trolley, and the camera trolley is provided with a camera trolley wheel, and the position of the camera is moved by the camera trolley wheel; the movable drill bit includes a vertical section and a horizontal section, and the camera bracket adopts a cylindrical frame structure, and the cylindrical frame structure includes a plurality of rings and a plurality of straight rods connecting the rings; the camera One end of the horizontal section is rotatably connected to the inner wall of the drill bit slot; the connecting component includes a drill bit rotating shaft connecting the power drive component and the fixed drill bit; the connecting component also includes a plurality of movable drill bit connecting components corresponding to a plurality of movable drill bits, and the movable drill bit connecting component includes an adjusting rotary head fixedly sleeved on the outside of the drill bit rotating shaft, and an adjusting rod respectively connecting the adjusting rotary head and the fixed drill bit; an adjusting rotary head groove is provided on the end surface of the adjusting rotary head for the rear end of the adjusting rod to extend into, and the adjusting rotary head groove is communicated with a bolt hole circumferentially provided on the side wall of the adjusting rotary head, and the adjusting rod fixedly inserted into the bolt hole The adjusting rod is positioned by the positioning bolt, and a drill bit groove is provided at the rear end of the fixed drill bit, and the front end of the adjusting rod extends into the drill bit groove and into the drill bit groove connected with the corresponding drill bit groove; the front end of the adjusting rod is provided with a clamping strip resting on the bottom of the horizontal section, and the adjusting rod is pushed to drive the clamping strip to move toward the front end of the drill bit groove, lifting the horizontal section of the movable drill bit, so that the vertical section of the movable drill bit extends out of the drill bit groove, so that the movable drill bit is transformed from a storage state to a working state; a clamping strip drill bit is provided in the clamping strip, and the clamping strip on the adjusting rod is pushed to move to the outside of the movable drill bit, and the clamping strip drill bit extends out from the inside of the clamping strip, thereby realizing a variable drill bit diameter.

2. The tunnel excavation water inrush visualization test device according to claim 1, characterized in that: The water pressure loading structure includes a water tank, a water outlet is provided on one side of the water tank, and a bayonet with an internal thread is provided on the other side of the water tank. A piston is provided in the water tank, and the piston and the water tank form a closed water storage chamber. A transmission is provided on the side of the piston close to the bayonet, and a rotor is provided in the transmission, and the rotor slides on the inner wall of the transmission. The rotor is fixedly connected to a water pressure loading transmission shaft, one end of the water pressure loading transmission shaft extends into the opening of the transmission, and the outer middle section of the water pressure loading transmission shaft is provided with an external thread adapted to the internal thread, and the other end of the water pressure loading transmission shaft is connected to the output end of the motor; a reversing device is provided on one side of the water outlet, and the reversing device is respectively connected to the water inlet pipe and the water outlet pipe, and the water inlet pipe is communicated with the water tank. A water inlet pipe valve is provided at the connection between the reversing device and the water inlet pipe, and a water outlet pipe valve is provided at the connection between the reversing device and the water outlet pipe; the water pressure loading structure also includes a water pressure loading motor switch for controlling the direction of the water pressure loading motor.

3. A test method, characterized in that: The tunnel excavation water inrush visualization test device according to any one of claims 1 to 2 comprises the following steps: S1, applying initial internal water pressure: closing the water outlet valve and opening the water inlet valve, turning on the water pressure loading motor switch and reversing it to fill the water tank with water, and turning off the water pressure loading motor switch after the water tank is full; S2, applying confining pressure: applying pressure to the pressure plate to make the confining pressure value of the tunnel specimen reach a preset value; S3, applying test internal water pressure: turning on the water pressure loading motor switch and rotating it forward to make the internal water pressure value in the blind hole reach a predetermined internal water pressure value, and then turning off the water pressure loading motor switch to maintain a constant internal water pressure value; S4, Drilling and Excavation: Control all active drill bits to be in working state, start the drill motor, move the drilling trolley to drill and excavate, and turn on the camera to shoot the inner wall of the tunnel; S5, Photographing the Tunnel Face: Control some active drill bits to be in the storage state, and shoot the tunnel face; S6, Repeat S4 to S5 until the tunnel is damaged, turn off the drill motor, and the test ends.

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