Hydraulic tunnel surrounding rock instability early warning device based on microseismic signals

Abstract

The invention relates to the technical field of hydraulic tunnel surrounding rock instability early warning, in particular to a hydraulic tunnel surrounding rock instability early warning device based on microseismic signals, which comprises a linear framework and a curve mounting framework, one side surface of the linear framework and one side surface of the curve mounting framework are both provided with wire groove sealing strips, and the bottom of the linear framework is provided with a bottom wire plate. The modular three-dimensional framework has the beneficial effects that the modular three-dimensional framework is formed by fixedly connecting the linear framework and the curve mounting framework through clamping bolts, and the modular three-dimensional framework can extend along the trend of a hole axis and adapt to a fluctuating section; three-dimensional distribution points of 5 m, 40 m and 80 m are formed on the rear side of a construction tunnel face, the installation difficulty of the micro-seismic signal sensors is reduced through cooperation of the micro-seismic sensor installation pipes and the cement pouring guide pipes, it is guaranteed that probes of the micro-seismic signal sensors are tightly attached to the side wall of the hydraulic tunnel, and micro-seismic signals generated by the side wall of the hydraulic tunnel are captured in time.

Description

Technical Field

[0001] This invention belongs to the field of early warning technology for rock instability in hydraulic tunnels, specifically relating to an early warning device for rock instability in hydraulic tunnels based on microseismic signals. Background Technology

[0002] Early warning of surrounding rock instability in hydraulic tunnels is a crucial aspect of ensuring the safety of tunnel construction and operation. Through real-time monitoring and scientific analysis, potential risks of instability such as fracturing, deformation, or rockbursts in the surrounding rock can be identified in advance, allowing for timely countermeasures. Current technologies typically employ microseismic signals to monitor the instability of surrounding rock in hydraulic tunnels. Specifically, microseismic sensors capture internal rock fracture signals to provide dynamic early warning of rockbursts or instability. Before instability, the rock undergoes a process of "micro-crack initiation – propagation – penetration," accompanied by microseismic signals of 0-100 Hz. These signals are collected in real-time by an array of sensors, filtered, and framed to extract multiple precursor features. The data is then uploaded to a data model for analysis. Finally, if instability characteristics are detected, a graded early warning signal is issued. At this point, construction personnel can be evacuated from the hydraulic tunnel construction environment in advance to prevent accidents, achieving continuous monitoring and early warning.

[0003] A Chinese patent document with publication number CN117782921A discloses a testing device and method for simulating the initiation of soil particle migration in weak interlayers in tunnels under simulated in-situ water pressure. The method involves setting up a test chamber containing a sample of surrounding rock with weak interlayers, along with a water supply system, a pressurization system, a water pressure measuring device, and a deformation measuring device. The sample and pressurization system simulate the natural in-situ stress conditions of the weak interlayers. A specified water pressure is applied to the test chamber through the water supply system. The water pressure measuring device measures the pressure gradient change in the weak interlayers. The deformation measuring device reflects the significant displacement of the weak interlayers as a condition for determining the initiation of soil particle migration. This allows for the measurement of the critical water pressure gradient of the weak interlayers in the tunnel surrounding rock under simulated conditions, thus enabling the assessment of tunnel surrounding rock under natural conditions. Quantitative research on seepage failure provides technical support for determining tunnel surrounding rock instability and predicting and warning of water inrush and mudslide disasters. However, the above methods only provide theoretical data support by establishing experimental chambers. The actual construction environment of hydraulic tunnels is very complex, and the boundary conditions of the experimental chambers are distorted. Due to the rigid constraints around the experimental chambers, the stress at the construction site is dispersed and the lateral unloading is significantly reduced. Furthermore, there is a three-dimensional difference in the stress field between the experimental chambers and the actual construction environment. The experiment can only apply constant axial and lateral loads and cannot simulate the true three-dimensional path of "tangential stress concentration - radial stress relaxation" after tunnel excavation. Therefore, the warning threshold of the experimental chambers has a significant lag, and relying on the warning threshold of the experimental chambers for early warning of surrounding rock instability in hydraulic tunnels carries certain risks.

[0004] Therefore, this invention proposes an early warning device for the instability of surrounding rock in hydraulic tunnels based on microseismic signals. This addresses the problem in existing technologies that rely on establishing experimental chambers to measure the critical water pressure gradient of weak interlayers in the surrounding rock of hydraulic tunnels under simulated conditions, thereby quantitatively studying seepage damage to the surrounding rock of hydraulic tunnels under natural conditions. This approach addresses the significant lag in the early warning threshold for determining tunnel surrounding rock instability and predicting water inrush and mudslide disasters. By designing an integrated microseismic sensor installation structure, three cross-sectional three-dimensional array monitoring points are arranged behind the tunnel face to form a comprehensive, three-dimensional, real-time monitoring system for the instability signals of the surrounding rock in hydraulic tunnels, improving the accuracy and timeliness of the early warning. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an early warning device for rock instability of hydraulic tunnels based on microseismic signals, so as to solve the problems mentioned in the background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a hydraulic tunnel surrounding rock instability early warning device based on microseismic signals, comprising a straight frame and a curved installation frame. A groove sealing strip is provided on one side surface of both the straight frame and the curved installation frame. A bottom guide plate is provided at the bottom of the straight frame. A microseismic sensor installation tube is provided in the middle of the other side surface of both the straight frame and the curved installation frame. A cement grouting conduit is provided on one side of the microseismic sensor installation tube, and a microseismic signal sensor is provided inside the microseismic sensor installation tube.

[0007] Preferably, a sealing sleeve is fixedly installed on one side of the inner surface of the micro-vibration sensor mounting tube, and a through hole adapted to the micro-vibration signal sensor is provided in the middle of the sealing sleeve. A sealing cover is snapped onto one side of the sealing sleeve, and the side surface of the sealing cover is fixedly connected to the side surface of the straight frame and the curved mounting frame, respectively.

[0008] Preferably, a micro-vibration sensor mounting bracket is slidably mounted on the inner surface of the micro-vibration sensor mounting tube, a magnetic ring is fixedly mounted on one end of the micro-vibration sensor mounting bracket, elastic buckles are symmetrically and movably mounted on the side wall of the micro-vibration sensor mounting bracket, and the micro-vibration signal sensor is fixedly mounted in the middle of the micro-vibration sensor mounting bracket.

[0009] Preferably, a threaded rod is rotatably mounted on one side of the sealing sleeve, one end of the threaded rod is rotatably connected to the side wall of the micro-vibration sensor mounting tube, the inner wall of one side bracket of the micro-vibration sensor mounting bracket is threadedly connected to the outer surface of the threaded rod, and a limit rod is fixedly mounted on the other side of the sealing sleeve.

[0010] Preferably, a fixing ring is fixedly installed at one end of the cement injection conduit near the micro-vibration sensor mounting tube by bolts, and a cement injection guide ring is fixedly installed at the other end of the cement injection conduit. A limit sleeve is slidably installed on the inner surface of the cement injection conduit, and a cement extrusion plate is fixedly installed at one end of the limit sleeve near the cement injection guide ring. An isolation film is fixedly installed in the middle of the inner wall of the cement extrusion plate.

[0011] Preferably, the other end of the limiting sleeve is provided with a sliding groove that is compatible with the micro-vibration sensor mounting bracket, and an elastic support ring is fixedly installed inside the threaded rod, with a magnetic ring fixedly installed at one end of the elastic support ring.

[0012] Preferably, an outer sealing sleeve is fixedly installed on the inner surface of the limiting sleeve, and an inner sealing sleeve adapted to the outer sealing sleeve is fixedly installed above the probe of the micro-vibration signal sensor.

[0013] Preferably, the side surface of the fixing ring is symmetrically fixed with locking buckles, the side wall of the micro-vibration sensor mounting tube is provided with a slot adapted to the locking buckle, the inside of the locking buckle is movably installed with a spring locking pin, and the side wall of the slot of the micro-vibration sensor mounting tube is provided with a locking groove adapted to the spring locking pin.

[0014] Preferably, the micro-vibration sensor mounting tube has symmetrically and movably mounted connecting locking posts on its sidewalls, and a toggle lever is slidably mounted in the middle of the connecting locking posts. The sidewall of the micro-vibration sensor mounting tube is provided with a sliding groove adapted to the toggle lever, and a compression spring is fixedly installed inside the sliding groove. One end of the compression spring contacts the side surface of the toggle lever. An elastic washer is provided between the outer sidewall of the toggle lever and the sliding groove of the micro-vibration sensor mounting tube. The sidewall of the micro-vibration sensor mounting tube has an adjustment hole adapted to the compression spring.

[0015] Preferably, one end of the straight frame is provided with a slot, the other end of the straight frame is provided with a clip, one side surface of the straight frame is provided with a groove, and the structure of the curved mounting frame is the same as that of the straight frame.

[0016] Compared with the prior art, the beneficial effects of the present invention are: By designing a modular three-dimensional framework that combines a straight frame with a curved installation frame secured by bolts, this framework can extend along the tunnel axis and adapt to undulating cross-sections. This allows for a three-dimensional layout of points at 5 m, 40 m, and 80 m behind the construction face. The microseismic sensor installation pipe, in conjunction with the cement grouting conduit, reduces the installation difficulty of the microseismic signal sensors, ensuring the sensor probes are tightly fitted to the sidewall of the hydraulic tunnel and promptly capture microseismic signals generated by the tunnel sidewall. As the construction face advances, when it reaches 35 m, the set furthest from the face is disassembled and reinstalled 5 m behind the new face. This design only requires alternating disassembly and installation of one set of framework and sensors as construction progresses, facilitating the later layout and positioning of the microseismic signal sensors and significantly reducing installation difficulty, achieving rapid installation, precise positioning, and comprehensive early warning. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall installation layout structure of the present invention; Figure 2 This is a schematic diagram illustrating the installation effect in the construction environment of the present invention; Figure 3 This is a schematic diagram of a single connection structure between the curved mounting frame and the groove sealing strip of the present invention; Figure 4 This is a schematic diagram of the structure of the groove sealing strip after disassembly according to the present invention; Figure 5 This is a schematic diagram of the structure of the curved mounting frame after separation from the groove sealing strip of the present invention; Figure 6 This is a schematic diagram of the structure of the cement injection conduit after separation from the linear skeleton of the present invention; Figure 7 This is a schematic diagram of one side of the cement injection conduit after it is separated from the straight skeleton according to the present invention; Figure 8 This is a schematic diagram of the structure of the micro-vibration sensor mounting tube and the cement grouting conduit after disassembly according to the present invention; Figure 9 This is a schematic diagram of the micro-vibration sensor mounting pipe and cement grouting conduit of the present invention in a preliminary installation state. Figure 10 This is a cross-sectional view of the micro-vibration sensor mounting tube and the cement grouting conduit housing of the present invention at point A-A, showing them in the initial installation state. Figure 11 This is a cross-sectional view of the micro-vibration sensor mounting tube and cement grouting conduit of the present invention in a preliminary installation state at point A-A. Figure 12 For the present invention Figure 11 A magnified structural diagram at point A; Figure 13 This is a cross-sectional view of the micro-vibration sensor mounting tube and cement grouting conduit of the present invention at point A-A, showing the overall internal structure before installation. Figure 14 This is a schematic diagram of the micro-vibration sensor mounting pipe and cement grouting conduit of the present invention in the overall installed state. Figure 15 This is a schematic cross-sectional view of the micro-vibration sensor mounting tube and the cement grouting conduit housing of the present invention at point B-B, showing the installation completed. Figure 16 This is a cross-sectional view of the micro-vibration sensor mounting tube and cement grouting conduit of the present invention at point B-B, showing the entire internal structure of the installed micro-vibration sensor mounting tube and cement grouting conduit in a completed state. Figure 17 For the present invention Figure 16 A magnified structural diagram at point B.

[0018] In the diagram: 1. Straight frame; 2. Curved mounting frame; 3. Groove sealing strip; 4. Bottom guide plate; 5. Micro-vibration sensor mounting tube; 51. Sealing sleeve; 52. Sealing cover; 53. Micro-vibration sensor mounting bracket; 531. Elastic buckle; 532. Magnetic ring one; 54. Threaded rod; 541. Threaded rod knob; 542. Locking slider; 55. Connecting locking post; 551. Actuating rod; 552. Compression spring; 6. Cement grouting conduit; 61. Cement grouting guide ring; 62. Fixing ring; 621. Locking buckle; 622. Spring locking pin; 63. Cement extrusion plate; 631. Isolation film; 64. Limiting sleeve; 641. Elastic support ring; 642. Magnetic ring two; 65. Outer sealing sleeve; 651. Inner sealing sleeve; 7. Hydraulic tunnel; 8. Construction face; 9. Micro-vibration signal sensor. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clear and complete, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some, not all, embodiments of the present invention, and are merely illustrative of the embodiments of the present invention. They are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0020] Please refer to Figures 1 to 17This invention provides a technical solution: a hydraulic tunnel surrounding rock instability early warning device based on microseismic signals, comprising a straight frame 1 and a curved mounting frame 2. One end of the straight frame 1 is provided with a slot, and the other end with a clamping head. A groove is provided on one side surface of the straight frame 1. The curved mounting frame 2 has the same structure as the straight frame 1. A groove sealing strip 3 is provided on one side surface of both the straight frame 1 and the curved mounting frame 2. A bottom guide plate 4 is provided at the bottom of the straight frame 1. A microseismic sensor mounting tube 5 is provided in the middle of the other side surface of both the straight frame 1 and the curved mounting frame 2. A cement grouting conduit 6 is provided on one side of the microseismic sensor mounting tube 5. The cement grouting conduit 6 has a length of 0.5m, and the microseismic sensor mounting tube 5 has a length of 1.4m. A microseismic signal sensor 9 is installed inside the microseismic sensor mounting tube 5. In this embodiment, the straight frame 1 and the curved mounting frame 2 are combined to form a complete frame. After the curved mounting frame 2 is installed end-to-end, it is fixed with bolts. The installation layout can be customized according to the specific construction environment of the hydraulic tunnel. The micro-vibration sensor mounting tubes 5 are distributed on the outside of the straight frame 1 and the curved mounting frame 2. The micro-vibration signal sensor 9 is installed inside the micro-vibration sensor mounting tubes 5. This not only facilitates the installation of the micro-vibration signal sensor 9 into the surrounding rock cavity of the hydraulic tunnel, but also protects the micro-vibration signal sensor 9. The grooves of the straight frame 1 and the curved mounting frame 2 facilitate the wiring of the micro-vibration signal sensor 9. The groove sealing strip 3 not only seals the grooves of the straight frame 1 and the curved mounting frame 2, protecting the wiring of the micro-vibration signal sensor 9, but also, when the groove sealing strip 3 is fixed to the straight frame 1 and the curved mounting frame 2 with bolts, it further reinforces the grooves and clamp connections of the straight frame 1 and the curved mounting frame 2, making the distribution of the micro-vibration signal sensor 9 stable. For specific installation methods, see attached figure. Figure 2As shown, the straight frame 1 and the curved installation frame 2 form three sets of three-dimensional frames, which are set inside the hydraulic tunnel 7. The initial positions are 5m, 40m and 80m away from the construction face 8, respectively. They respectively achieve the triple function of focusing on capturing the fracture in front of the face, tracking the continuous deterioration of the surrounding rock, and serving as a reference for background noise. The interval between adjacent microseismic signal sensors 9 in the same set is 15m, and the microseismic signal sensors 9 on the three sets of frames are staggered. A three-dimensional microseismic sensor array is constructed on the back side of the construction face 8. The straight frame 1 and the curved installation frame 2 are connected by snap-fit ​​and bolt to form a modular three-dimensional frame, which can extend with the tunnel axis and adapt to the undulating cross section. The bottom guide plate 4 mainly organizes the wiring of all the microseismic signal sensors 9 at the bottom. The cable groove sealing strip 3 cover plate not only seals the wiring but also locks the joints for a second time, so that the entire array can be completed in the narrow tunnel without support or welding at distances of 5m, 40m and 80m. The three-level outpost-monitoring-background deployment of the microseismic sensor installation tube 5 isolates the microseismic signal sensor 9 from the rock wall, shotcrete, and blasting debris. The microseismic signal sensors 9 in the same group are regularly distributed with only a 15 m spacing between them, which takes into account both high signal-to-noise ratio acquisition and maintenance and replacement, and achieves the effects of rapid installation, accurate positioning, and comprehensive early warning. As the construction face 8 continues to advance, when the construction face 8 advances 35 m, the group furthest from the face is disassembled and reinstalled at a position 5 m behind the new construction face 8. This design only requires the sequential disassembly and installation of one set of frame and sensor as the construction progresses, which not only facilitates the layout and positioning of the microseismic signal sensor 9 in the later stage, but also greatly reduces the installation difficulty. A sealing sleeve 51 is fixedly installed on one side of the inner surface of the micro-vibration sensor mounting tube 5. A through hole adapted to the micro-vibration signal sensor 9 is provided in the middle of the sealing sleeve 51. A sealing cover 52 is snapped onto one side of the sealing sleeve 51. The side surface of the sealing cover 52 is fixedly connected to the side surfaces of the straight frame 1 and the curved mounting frame 2, respectively. A micro-vibration sensor mounting bracket 53 is slidably installed on the inner surface of the micro-vibration sensor mounting tube 5. A magnetic ring 532 is fixedly installed at one end of the micro-vibration sensor mounting bracket 53. Elastic buckles 531 are symmetrically and movably installed on the side walls of the micro-vibration sensor mounting bracket 53. The micro-vibration signal sensor 9 is fixedly mounted... A threaded rod 54 is rotatably mounted on one side of a sealing sleeve 51, located in the middle of a micro-vibration sensor mounting bracket 53. One end of the threaded rod 54 is rotatably connected to the side wall of the micro-vibration sensor mounting tube 5. The inner wall of one side of the micro-vibration sensor mounting bracket 53 is threadedly connected to the outer surface of the threaded rod 54. A threaded rod knob 541 is rotatably mounted on the outer surface of the sealing sleeve 51. A set of meshing gears are fixedly mounted on one end of the threaded rod knob 541 and the outer surface of the threaded rod 54. A locking slider 542 is also provided on one side of the threaded rod knob 541 to limit the movement of the threaded rod knob 541. On the other side of 1, a limiting rod is fixedly installed. In this embodiment, the micro-vibration sensor mounting tube 5 mainly serves to protect the micro-vibration signal sensor 9. First, a hole with a diameter matching the micro-vibration sensor mounting tube 5 is opened on the side wall of the hydraulic tunnel 7. The depth of the hole is 2m, which is the sum of the lengths of the micro-vibration sensor mounting tube 5 and the cement grouting conduit 6. Then, the micro-vibration sensor mounting tube 5 is placed inside the hole. First, the locking slider 542 is rotated away from the threaded rod knob 541 to cancel its limiting. Then, the threaded rod knob 541 is rotated to drive the threaded rod 54 to rotate, so that the micro-vibration sensor mounting bracket 53 is in place for the micro-vibration sensor mounting. The micro-vibration signal sensor 9 is pushed into the inner side of the cement grouting conduit 6 by sliding inside the pipe 5. After the micro-vibration signal sensor 9 is in place, the locking slider 542 is rotated to lock the threaded rod knob 541 to a limit position. Finally, the straight frame 1 or the curved installation frame 2 is installed on the outside of the micro-vibration sensor installation pipe 5 to ensure that the sealing cover 52 is engaged with the micro-vibration sensor installation pipe 5, thus completing the sealing of the micro-vibration sensor installation pipe 5. After the straight frame 1 and the curved installation frame 2 are assembled, the whole frame composed of the straight frame 1 and the curved installation frame 2 is fixed on the outside of the hydraulic tunnel 7 using a long spiral. Example 2

[0021] Please refer to Figures 1 to 17Based on Embodiment 1, to ensure a tight fit between the microseismic signal sensor 9 and the sidewall of the hydraulic tunnel 7, this embodiment further proposes that a fixing ring 62, 0.1m in length, be bolted to one end of the cement grouting conduit 6 near the microseismic sensor mounting pipe 5. A cement grouting guide ring 61, also 0.1m in length, is fixedly installed at the other end of the cement grouting conduit 6. A limiting sleeve 64 is slidably installed on the inner surface of the cement grouting conduit 6, close to the cement grouting guide ring 61. A cement extrusion plate 63 is fixedly installed at one end of the limiting sleeve 64. An isolation film 631 is fixedly installed in the middle of the inner wall of the cement extrusion plate 63. A sliding groove adapted to the micro-vibration sensor mounting bracket 53 is opened at the other end of the limiting sleeve 64. An elastic support ring 641 is fixedly installed inside the threaded rod 54. A magnetic ring 642 is fixedly installed at one end of the elastic support ring 641. An outer sealing sleeve 65 is fixedly installed on the inner surface of the limiting sleeve 64. An inner sealing sleeve 651 adapted to the outer sealing sleeve 65 is fixedly installed above the probe of the micro-vibration signal sensor 9. In this embodiment, the cement injection conduit 6 is detachably installed at one end of the microseismic sensor mounting pipe 5 via a fixing ring 62. It is used to inject cement into the pre-drilled hole in the hydraulic tunnel 7. The fixing ring 62 not only connects the microseismic sensor mounting pipe 5 but also limits the movement of the limiting sleeve 64. The limiting sleeve 64 not only limits the movement of the microseismic sensor mounting bracket 53 but also installs the cement extrusion plate 63 and the outer sealing sleeve 65. The specific installation process is as follows: the cement injection conduit 6 is installed at one end of the microseismic sensor mounting pipe 5. The limiting sleeve 64 and the cement extrusion plate 63 are adjusted to move as a whole to the limiting position of the fixing ring 62, which is the pre-installation position. At this time, the cavity length for injecting cement slurry between the cement extrusion plate 63 and the cement injection guide ring 61 is 0.2m. Then, cement slurry is injected into one side of the cement extrusion plate 63, ensuring the cement slurry thickness reaches at least to one side of the triangular groove of the cement injection guide ring 61. Finally, the microseismic sensor mounting pipe 5 and the cement injection conduit 6 are inserted as a whole into the pre-drilled hole in the hydraulic tunnel 7. Inside the prepared hole, rotating the threaded rod knob 541 causes the threaded rod 54 to rotate, driving the micro-vibration sensor mounting bracket 53 forward. During this forward movement, the mounting bracket 53 inserts into the limiting sleeve 64, and the magnetic ring 532 and magnetic ring 642 come into contact and adhere together, marking the initial installation position. Continuing to advance the mounting bracket 53, the limiting sleeve 64 moves further towards the cement injection guide ring 61. The cement extrusion plate 63 pushes cement slurry to the bottom of the hole, overflowing from the triangular groove of the cement injection guide ring 61, connecting the bottom of the hole to the cement injection conduit 6. Further advancing the mounting bracket 53 compresses the elastic support ring 641 until the probe of the micro-vibration signal sensor 9 is in close contact with the isolation film 631, marking the completed installation position. At this point, the inner sealing sleeve 651 and the outer sealing sleeve 65 are properly fitted, improving the probe sealing of the micro-vibration signal sensor 9. The isolation film 631 needs to be selected with an impedance close to that of the rock material, for example, 0.1–0.5. To ensure there are no gaps between the probe and the isolation film 631, a thin layer of silicone grease can be applied to the probe of the micro-vibration signal sensor 9 at the beginning of installation. After the cement slurry dries, this ensures that the probe of the micro-vibration signal sensor 9 fits tightly against the sidewall of the hydraulic tunnel 7, allowing for timely capture of micro-vibration signals generated by the sidewall of the hydraulic tunnel 7. The cement injection conduit 6 is designed to improve the efficiency of cement slurry pouring and ensure a tight installation of the probe of the micro-vibration signal sensor 9. Most importantly, compared to directly injecting cement to encapsulate the probe, which would render the probe unusable later and could be loosely installed with interference factors such as air bubbles, the micro-vibration signal sensor 9 is installed by using the cement injection conduit 6 and the micro-vibration sensor installation tube 5. The micro-vibration signal sensor 9 can be removed and reused later, and the installation is also more secure. Example 3

[0022] Please refer to Figures 1 to 17 Based on Embodiment 2, to facilitate the installation and disassembly of the micro-vibration sensor mounting tube 5 and the cement grouting conduit 6, this embodiment further proposes that locking buckles 621 are symmetrically fixedly installed on the side surface of the fixing ring 62, and the side wall of the micro-vibration sensor mounting tube 5 has a slot adapted to the locking buckle 621. A spring locking pin 622 is movably installed inside the locking buckle 621, and the side wall of the slot of the micro-vibration sensor mounting tube 5 has a locking groove adapted to the spring locking pin 622. The side wall of the micro-vibration sensor mounting tube 5 is symmetrically fixedly installed with locking buckles 621. The device is equipped with a connecting locking post 55, and a toggle lever 551 is slidably installed in the middle of the connecting locking post 55. The side wall of the micro-vibration sensor mounting tube 5 is provided with a sliding groove that matches the toggle lever 551. A compression spring 552 is fixedly installed inside the sliding groove. One end of the compression spring 552 is in contact with the side surface of the toggle lever 551. An elastic gasket is provided between the outer side wall of the toggle lever 551 and the sliding groove of the micro-vibration sensor mounting tube 5. An adjustment hole that matches the compression spring 552 is opened on the side wall of the micro-vibration sensor mounting tube 5. In this embodiment, during the initial installation of the cement grouting conduit 6, the locking buckle 621 is inserted into the slot of the micro-vibration sensor mounting tube 5. At this time, the actuating rod 551 is pressed by the compression spring 552, which indirectly drives the connecting locking pin 55 to compress the spring locking pin 622, causing the spring locking pin 622 to be pushed outward and inserted into the side wall locking groove of the micro-vibration sensor mounting tube 5, thus completing the installation between the micro-vibration sensor mounting tube 5 and the cement grouting conduit 6. When the micro-vibration sensor mounting bracket 53 is pushed forward, the elastic buckle 531 is squeezed when it passes the protrusion of the actuating rod 551, allowing the micro-vibration sensor mounting bracket 53 to pass smoothly. When disassembly is required later, the threaded rod 54 is rotated in the opposite direction, causing the micro-vibration sensor mounting bracket 53 to pull out the micro-vibration signal sensor 9. During the process, the elastic buckle 531 will collide with the protrusion of the lever 551. As the micro-vibration sensor mounting bracket 53 is pulled out, the lever 551 and the connecting locking pin 55 are pulled out as a whole. At this time, the compression spring 552 is compressed, the spring locking pin 622 is reset, and the locking ring 62 is released from locking with the micro-vibration sensor mounting tube 5. At this time, the micro-vibration sensor mounting tube 5 can be pulled out as a whole. It can be used again after replacing with a new cement grouting conduit 6. It should be noted that after the micro-vibration sensor mounting tube 5 is pulled out as a whole, the adjustment hole cover on the side wall is opened, and the lever 551 is pulled outward so that the protrusion position avoids the elastic buckle 531. This allows the micro-vibration sensor mounting bracket 53 to continue to be adjusted and moved back to the initial position without affecting subsequent use. Example 4

[0023] Please refer to Figures 1 to 17 Based on Example 3, this example also proposes a method for using the early warning device for rock instability of hydraulic tunnels based on microseismic signals, including the following steps: Step 1, Installation Preparation: Drill positioning holes on the side wall of the hydraulic tunnel 7, install the cement grouting conduit 6 on one side of the micro-vibration sensor installation pipe 5, and adjust the limiting sleeve 64 and the cement extrusion plate 63 to move as a whole to the limiting position of the fixing ring 62. Step two: Install the cement extrusion plate 63 by injecting cement slurry into one side of the cement extrusion guide ring 61, ensuring that the cement slurry thickness reaches at least to one side of the triangular groove of the cement slurry guide ring 61. Then, insert the micro-vibration sensor mounting tube 5 and the cement slurry guide tube 6 into the pre-drilled hole in the hydraulic tunnel 7. Rotate the threaded rod knob 541 to make the threaded rod 54 rotate and drive the micro-vibration sensor mounting bracket 53 forward. The cement extrusion plate 63 pushes the cement slurry to the bottom of the hole and overflows from the triangular groove of the cement slurry guide ring 61, connecting the bottom of the hole with the cement slurry guide tube 6 as a whole. Then, continue to push the micro-vibration sensor mounting bracket 53 forward until the probe of the micro-vibration signal sensor 9 is in close contact with the isolation film 631. Step 3: Organize and package the microseismic signal sensor 9. Organize the connecting wires so they pass through the sealing cover 52. Install the straight frame 1 or curved mounting frame 2 on the outside of the microseismic sensor mounting tube 5, ensuring the sealing cover 52 and the microseismic sensor mounting tube 5 are properly engaged. Complete the sealing of the microseismic sensor mounting tube 5. Install the straight frame 1 and curved mounting frame 2 sequentially to form a modular three-dimensional frame. Extend along the tunnel axis to complete the three-dimensional layout at distances of 85 m, 40 m, and 80 m from the working face. Extend all the lines of the microseismic signal sensor 9 through the bottom conductor plate 4, connect them in series, and then connect them to the signal acquisition equipment. Real-time acquisition, noise filtering, and frame segmentation are performed to extract multiple precursor feature data. The data is uploaded to the server for data model analysis. If instability characteristics occur, a graded early warning signal is issued. The microseismic signal sensor 9 can be a microseismic signal sensor with a frequency response range of 0.1-100Hz. After the microseismic signal sensor 9 is arranged, use a long spiral to fix the overall frame composed of the straight frame 1 and curved mounting frame 2 on the outside of the hydraulic tunnel 7. Use the groove sealing strip 3 to seal the groove.

[0024] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hydraulic tunnel surrounding rock instability early warning device based on microseismic signals, comprising a straight frame (1) and a curved installation frame (2), wherein a groove sealing strip (3) is provided on one side surface of both the straight frame (1) and the curved installation frame (2), and a bottom guide plate (4) is provided at the bottom of the straight frame (1), characterized in that: Micro-vibration sensor mounting tubes (5) are provided on the middle of the other side surface of both the straight frame (1) and the curved mounting frame (2). A cement grouting conduit (6) is provided on one side of the micro-vibration sensor mounting tube (5). A micro-vibration signal sensor (9) is provided inside the micro-vibration sensor mounting tube (5).

2. The early warning device for rock instability of hydraulic tunnels based on microseismic signals according to claim 1, characterized in that: A sealing sleeve (51) is fixedly installed on one side of the inner surface of the micro-vibration sensor mounting tube (5). A through hole adapted to the micro-vibration signal sensor (9) is provided in the middle of the sealing sleeve (51). A sealing cover (52) is snapped onto one side of the sealing sleeve (51). The side surface of the sealing cover (52) is fixedly connected to the side surface of the straight frame (1) and the curved mounting frame (2), respectively.

3. The early warning device for rock instability of hydraulic tunnels based on microseismic signals according to claim 2, characterized in that: The micro-vibration sensor mounting tube (5) has a micro-vibration sensor mounting bracket (53) slidably mounted on its inner surface. A magnetic ring (532) is fixedly mounted on one end of the micro-vibration sensor mounting bracket (53). Elastic buckles (531) are symmetrically and movably mounted on the side wall of the micro-vibration sensor mounting bracket (53). The micro-vibration signal sensor (9) is fixedly mounted in the middle of the micro-vibration sensor mounting bracket (53).

4. The early warning device for rock instability of hydraulic tunnels based on microseismic signals according to claim 3, characterized in that: A threaded rod (54) is rotatably mounted on one side of the sealing sleeve (51). One end of the threaded rod (54) is rotatably connected to the side wall of the micro-vibration sensor mounting tube (5). The inner wall of one side bracket of the micro-vibration sensor mounting bracket (53) is threadedly connected to the outer surface of the threaded rod (54). A limit rod is fixedly mounted on the other side of the sealing sleeve (51).

5. The early warning device for rock instability of hydraulic tunnels based on microseismic signals according to claim 4, characterized in that: A fixing ring (62) is fixedly installed at one end of the cement grouting conduit (6) near the micro-vibration sensor mounting pipe (5) by bolts. A cement grouting guide ring (61) is fixedly installed at the other end of the cement grouting conduit (6). A limit sleeve (64) is slidably installed on the inner surface of the cement grouting conduit (6). A cement extrusion plate (63) is fixedly installed at one end of the limit sleeve (64) near the cement grouting guide ring (61). An isolation film (631) is fixedly installed in the middle of the inner wall of the cement extrusion plate (63).

6. The early warning device for rock instability of hydraulic tunnels based on microseismic signals according to claim 5, characterized in that: The other end of the limiting sleeve (64) is provided with a sliding groove that is compatible with the micro-vibration sensor mounting bracket (53). An elastic support ring (641) is fixedly installed inside the threaded rod (54), and a magnetic ring (642) is fixedly installed at one end of the elastic support ring (641).

7. The early warning device for rock instability of hydraulic tunnels based on microseismic signals according to claim 6, characterized in that: An outer sealing sleeve (65) is fixedly installed on the inner surface of the limiting sleeve (64), and an inner sealing sleeve (651) adapted to the outer sealing sleeve (65) is fixedly installed above the probe of the micro-vibration signal sensor (9).

8. The early warning device for rock instability of hydraulic tunnels based on microseismic signals according to claim 5, characterized in that: The side surface of the fixed ring (62) is symmetrically fixed with locking buckles (621), and the side wall of the micro-vibration sensor mounting tube (5) is provided with a slot that matches the locking buckle (621). The locking buckle (621) is movably installed with a spring locking pin (622), and the side wall of the slot of the micro-vibration sensor mounting tube (5) is provided with a locking groove that matches the spring locking pin (622).

9. The early warning device for rock instability of hydraulic tunnels based on microseismic signals according to claim 8, characterized in that: The micro-vibration sensor mounting tube (5) has symmetrically and movably mounted connecting locking pins (55) on its side wall. A toggle rod (551) is slidably mounted in the middle of the connecting locking pin (55). The side wall of the micro-vibration sensor mounting tube (5) is provided with a sliding groove that matches the toggle rod (551). A compression spring (552) is fixedly installed inside the sliding groove. One end of the compression spring (552) is in contact with the side surface of the toggle rod (551). An elastic gasket is provided between the outer side wall of the toggle rod (551) and the sliding groove of the micro-vibration sensor mounting tube (5). The side wall of the micro-vibration sensor mounting tube (5) is provided with an adjustment hole that matches the compression spring (552).

10. The early warning device for rock instability of hydraulic tunnels based on microseismic signals according to claim 1, characterized in that: One end of the straight frame (1) is provided with a slot, the other end of the straight frame (1) is provided with a head, and a groove is provided on one side surface of the straight frame (1). The structure of the curved mounting frame (2) is the same as that of the straight frame (1).

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