Detection equipment and evaluation method for monitoring and evaluating stability of surrounding rock around TBM gripper shoe by using rock mass speed change
By installing acoustic transmitting equipment group and receiving equipment group around the TBM boot, real-time monitoring of changes in rock mass velocity, the problem of surrounding rock instability caused by overloading the TBM boot is solved, and the safety and efficiency of tunnel construction are improved.
Patent Information
- Application Number
- CN202510270238.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2025-07-04
AI Technical Summary
In the prior art, during the TBM boot support work, there is a lack of monitoring of the performance of the surrounding rock formation, which leads to instability and collapse of the surrounding rock after the boot support pressure exceeds the surrounding rock load capacity, affecting the construction of the tunnel.
Design a detection equipment, including acoustic emission excitation equipment group, acoustic emission receiving equipment group, stretching device, hoisting mechanism and information processing equipment, evaluate the stability of surrounding rock by monitoring the change in the velocity of rock mass, and the equipment is installed around the TBM boot to detect the degree of surrounding rock damage in real time.
An efficient and accurate surrounding rock damage assessment has been achieved, which reduces the risk of surrounding rock collapse and improves the safety and efficiency of tunnel construction.
Smart Images
Figure CN120254047A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the related field of performance evaluation of the surrounding rock layer around the TBM support shoe during tunnel construction, and particularly to a detection device and an evaluation method for monitoring and evaluating the stability of the surrounding rock around the TBM support shoe by using the change of rock mass velocity. Background Art
[0002] With the rapid development of China's economic technology, our infrastructure construction has started to develop towards the mountainous areas in the west. A series of underground projects such as traffic tunnels, water diversion tunnels, and hydropower projects have been started. Compared with the traditional tunnel construction methods, the TBM (Tunnel Boring Machine) has the advantages of high efficiency, safety, environmental protection, and high automation, and is widely used in engineering construction. The open TBM relies on the support shoes to provide a large enough reaction force to the machine to push the TBM forward. In order to provide a large enough thrust for the TBM tunneling and ensure that the support shoes do not slip, the TBM support shoes usually apply a relatively large pressure to the surrounding rock. In the complex and changeable geological environment, whether the surrounding rock can withstand the pressure of the support shoes without being damaged has become the key to affecting the TBM tunneling. If the judgment is wrong, the support shoes may directly crush the surrounding rock, or cause the collapse of the surrounding rock during the recovery process of the support shoes. This will force the construction site to stop work and reinforce the surrounding rock at the position of the support shoes.
[0003] The method for monitoring and evaluating the damage of the surrounding rock at the TBM support shoe position by using the change of rock mass velocity is mainly based on the mechanical behavior change law of the rock mass under excavation disturbance. The corresponding relationship between wave velocity and damage degree: the wave velocity of the rock mass will decrease with the increase of the damage degree. When the wave velocity gradually decreases, it indicates that the volume of pores and fissures inside the rock mass begins to develop. When the wave velocity curve shows a fluctuating state, it means that the internal fissures of the rock mass extend to the surface, and the fissures develop rapidly and combine with each other to form a macroscopic fracture surface. When the wave velocity decreases rapidly, the rock mass is damaged and loses stability. The relationship between wave velocity and rock mass integrity: the rock mass integrity coefficient (fissure coefficient) can be calculated by wave velocity. The square of the ratio of the wave velocity of the intact rock to that of the damaged rock mass is the integrity coefficient, and the lower its value, the higher the damage degree of the rock mass.
[0004] The existing surrounding rock evaluation methods mostly rely on advanced geological forecasting or evaluation by the on-duty engineer's observation to decide whether to adopt other reinforcement measures before the support shoes. Among them, the scale of advanced geological forecasting is relatively large, and the potential internal micro-damage structures of the surrounding rock cannot be distinguished; manual discrimination depends on experience and can only be inferred from the appearance, and the risk points such as the hidden structural plane cannot be identified. Therefore, there is also an urgent need for an effective evaluation method on the construction site to ensure that the surrounding rock at the support shoe position can withstand the pressure of the support shoes without being damaged.
[0005] At the same time, due to the complex underlying environment and the difference in wave velocity transmission, the correlation between each single test is poor, and there is a problem of inaccurate test results. Summary of the Invention
[0006] The object of the present invention is to solve the problem in the prior art that during the operation of the TBM shoe, the monitoring of the performance of the surrounding rock formation is missing, resulting in the instability and collapse of the surrounding rock after the shoe pressure exceeds the bearing capacity of the surrounding rock, and further affecting the tunnel construction.
[0007] The specific solution of the present invention is as follows: Design a detection device for monitoring and evaluating the stability of the surrounding rock around the TBM shoe by using the change of rock mass velocity, including an acoustic emission excitation device group, an acoustic emission receiving device group, a stretching device for pulling the distance between the acoustic emission excitation device group and the acoustic emission receiving device group, a jacking mechanism for driving the acoustic emission excitation device group and the acoustic emission receiving device group into the rock formation, and an information processing device. The input end of the information processing device is connected to the acoustic emission excitation device group and the acoustic emission receiving device group; the output end of the information processing device is connected to an alarm and a shoe controller. Among them, with the shield cutter head as the front and the TBM tail as the rear, the acoustic emission excitation device group is in front of the shoe and the acoustic emission receiving device group is behind the shoe; at least three acoustic emission receiving sensors corresponding in shape and position are equidistantly arranged on each acoustic emission receiving device group; the acoustic emission excitation device group further includes a power input device, a transmission mechanism for transmitting power, and at least three synchronous power output devices. The power output devices are installed with plug-in drill rods through threaded connections, and at least 3 acoustic emission excitation sensors are arranged on the plug-in drill rods; the acoustic emission receiving device group includes a power input device, a transmission mechanism for transmitting power, and at least three power output devices. The power output devices are installed with plug-in drill rods through threaded connections, and at least 3 acoustic emission receiving sensors are arranged on the plug-in drill rods.
[0008] In specific implementation, the jacking mechanism includes a nut driven by a power source and a hydraulic mechanism for providing pressure to the drill rod in the nut. The hydraulic mechanism includes a pressure rod, and a collar is nested and installed in the pressure rod. The inner diameter of the collar is larger than the outer diameter of the drill rod.
[0009] In specific implementation, the acoustic emission receiving device group and the acoustic emission excitation device group are provided with card slots for fixing the stretching device. The stretching device includes an adjusting rod, and rotating nuts are sleeved on both sides of the adjusting rod. Different-handed screw rods are fitted in the rotating nuts, and clamping rings with the same shape and position as the card slots are provided at the ends of the screw rods.
[0010] In specific implementation, the card slot is a rotary slot, a positioning ring is provided in the rotary slot, and a rubber strip for increasing friction is laid in the rotary slot.
[0011] In specific implementation, a lateral limiting plate is slidably sleeved on the support shoe, and a guiding hole facilitating the passing of the cutting cylinder is formed in the lateral limiting plate; a circumferential limiting plate is also movably sleeved on the lateral limiting plate. The cutting cylinder above the support shoe passes through the circumferential limiting plate and drills into the rock formation. Meanwhile, an acoustic emission receiving device is sleeved in the cutting cylinder above the support shoe. A positioning pin type connection facilitating disassembly and assembly is provided between the circumferential limiting plate and the lateral limiting plate.
[0012] In specific implementation, a rotatable positioning ring is arranged outside the guiding hole, and an auxiliary pulling rope with a length of 1 meter or 2 meters is wound on the rotatable positioning ring. The inner diameter of the rotatable positioning ring is consistent with the outer diameter of the cutting rod, and a transitional fit connection is formed between the rotatable positioning ring and the cutting rod. The power mechanism is a belt drive mechanism.
[0013] It further includes a fixing mechanism for fixing the acoustic emission excitation equipment group and the acoustic emission receiving equipment group on the lining. The fixing mechanism includes a friction wheel installed on the hydraulic component fixing block. A screw hole for passing a set screw is formed in the middle of the friction wheel. A transfer wheel for transmitting power is arranged between the friction wheel and the transmission mechanism; a fork type switch for driving the conversion of its working position is installed on the transfer wheel; the set screw is preset in the screw hole, and the top forms a screw-nut fit with the corresponding electric mechanism.
[0014] In specific implementation, the structures of the friction wheel and the transfer wheel are replaced as the fixing mechanism includes a friction wheel installed on the hydraulic component fixing block. A sleeve is arranged in the middle of the friction wheel, and a screw hole for passing a set screw is formed in the sleeve. A sliding key connection is arranged between the friction wheel and the sleeve. When the friction wheel is at one end of the sliding key connection, the friction wheel forms power transmission with the transmission belt.
[0015] An evaluation method for monitoring and evaluating the damage degree of the surrounding rock around the TBM support shoe through the change of rock mass velocity mainly includes the following steps: Step 1: According to the current tunneling situation of the TBM, estimate the step-changing distance of the TBM at the shield tail position subsequently, and clarify that the step-changing distance is 1 step or half a step; Step 2: According to the step-changing distance determined in Step 1, combine the size of the shoe plate and set excitation holes and monitoring holes at positions 8 to 12 centimeters outward on both sides. The excitation hole is on one side of the shoe plate, and the receiving detection hole is on the other side of the shoe plate. The circumferential distance interval of the unilateral holes is more than 1 meter; Step 3: Drill holes. Use the L1 area bolt drill to drill the excitation and monitoring holes, and record the positions and horizontal angles of the drilled holes simultaneously, ensuring that the positions and horizontal angles of the corresponding holes on the left and right sides of the shoe plate are the same. The drilling depth is 1.8 to 2 m; Step 4: The embedding of the sensors is carried out after retracting the support shoes. The acoustic emission sensors of the drilling mechanism are installed in the holes, with a sensor spacing of 10 cm. The embedding starts from a depth of 2 m in the hole for 0.5 m, and 12 to 16 sensors are required for a single hole. On the left and right sides of the support shoes are the excitation and receiving acoustic emission sensors respectively. The sensors in the left hole are placed in the 3 o'clock direction, and the right ones are placed in the 9 o'clock direction. With the help of the stretching device, the sensors are well coupled with the rock wall. At the same time, the three-dimensional positions of the excitation and receiving acoustic wave sensors are calculated. Step 5: After moving the support shoes to the new support shoe position, extend them towards the surrounding rock wall and tighten them. During this process, the acoustic wave signals of the acoustic emission excitation sensors are alternately excited at intervals of 5 seconds, and records are made on the receiving side at the same time. Step 6: Conduct real-time processing of the monitoring, calculate and record the wave velocities between different excitation and receiving points. Step 7: Draw a graph of the wave velocity changing with time for the acoustic waves of different paths. Step 8: Give early warnings about the support shoe pressure or tunneling speed according to the wave velocity changes. For example, if the acoustic wave velocity changes exceed 5%, an early warning is issued, and if it exceeds 10%, collapse is inevitable.
[0016] The beneficial effects of the present invention are as follows: The site occupies a small area, which is convenient for workers to process. The synchronization performance of the equipment measurement is high, which can ensure the accurate correspondence between the transmitted signal and the received signal, form an accurate waveform atlas, analyze the wave velocity change and the deformation rate, and combine with the integrity coefficient calculation to evaluate the damage degree of the surrounding rock. An accurate result of the measurement environment can be obtained from one measurement, with high measurement efficiency and accurate results.
[0017] The measurement time is short, which does not affect the overall construction, and the support design can be optimized in time, such as increasing the number of bolts or adjusting the support structure. The installation positions of the entire acoustic emission excitation sensors and acoustic emission receiving sensors are accurate, and the synchronization rate between them is high, which improves the installation efficiency of the measurement equipment. There is no installation relationship between the measurement equipment and the support shoes themselves. To a certain extent, the interference between the support shoes and the measurement equipment is avoided. The measurement equipment can be self-contained and can decide whether to participate in the transmission according to needs, while the transmission terminal control equipment is a drilling-type positioning equipment that can be fixed on the lining or the rock mass, with accurate positioning and high positioning efficiency. The function of the stretching equipment is that it can achieve a good coupling effect between the detection equipment and the rock formation, ensuring the measurement effect. Description of the Drawings
[0018] Figure 1 is a schematic diagram of the schematic structure of the present invention; Figure 2 is a three-dimensional view of the schematic structure of the present invention; Figure 3 is the present inventionFigure 2 Front view of the shown structure; Figure 4 This is the present invention Figure 2 Top view of the shown structure; Figure 5 Left view of the assembled state of the present invention; Figure 6 Schematic diagram of power transmission of the middle conveyor belt, friction wheel and transfer wheel of the present invention; Figure 7 Front view of the stretching mechanism; Figure 8 This is Figure 2 Enlarged schematic diagram at position A in The threaded part in the drawings is omitted and not shown, and the drill pipe is outside the equipment; Names of each component in the figure: 1. Support shoe; 2. Motor; 3. Conveyor belt; 4. Three power output devices; 5. Cuttage rod; 6. Friction wheel; 7. Transfer wheel; 8. Fork; 9. Card slot; 10. Collar; 11. Pressing rod; 12. Rock mass; 13. Lining; 14; Adjusting rod; 15. Rotating nut; 16. Rubber strip. Specific implementation mode
[0019] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention. Embodiment 1
[0020] A TBM support shoe surrounding rock resistance evaluation device using the acoustic emission method, see Figures 1 to 3, including an acoustic emission excitation device group, an acoustic emission receiving device group, a stretching device for pulling the distance between the acoustic emission excitation device group and the acoustic emission receiving device group, a jacking mechanism for driving the acoustic emission excitation device group and the acoustic emission receiving device group into the rock formation, and an information processing device. The input end of the information processing device is connected to the acoustic emission excitation device group and the acoustic emission receiving device group; the output end of the information processing device is connected to an alarm and a boot controller. Among them, with the shield cutter head as the front and the TBM tail as the rear, the acoustic emission excitation device group is in front of the boot 1, and the acoustic emission receiving device group is behind the boot 1; at least three position-corresponding acoustic emission receiving sensors are equidistantly arranged on each acoustic emission receiving device group; the acoustic emission excitation device group further includes a power input device, a transmission mechanism for transmitting power, and at least three synchronous power output devices. The power output devices are installed with plug-in drill rods through threaded connections, and at least 3 acoustic emission excitation sensors are arranged on the plug-in drill rods; the acoustic emission receiving device group includes a power input device, a transmission mechanism for transmitting power, and at least three power output devices. The power output devices are installed with plug-in drill rods through threaded connections, and at least 3 acoustic emission receiving sensors are arranged on the plug-in drill rods.
[0021] During the working process, first estimate the area where the boot will be pressurized next time, and then install the acoustic emission excitation device group in the 3 o'clock direction of this area and the acoustic emission receiving device group in the 9 o'clock direction. During the installation process, the following installation requirements are synchronously achieved: 1. The coupling between the sensor and the rock formation is good to facilitate the transmission and reception of information; 2. The installation positions are such that the transmission and reception are opposite, and at the same time, each transmitting end is at the same angular position relative to the drill rod, and each receiving end is also at the same angular position relative to the drill rod, ensuring the consistency of the receiving conditions of each transmitting end and receiving end.
[0022] The jacking mechanism includes a nut driven by a power source and a hydraulic mechanism for providing pressure to the drill rod inside the nut. The hydraulic mechanism includes a pressure rod 11, and a collar 10 is nested inside the pressure rod 11. The inner diameter of the collar 10 is larger than the outer diameter of the drill rod. Since the drill rod is provided with a drilling power source through a lead screw and nut transmission mechanism, the function of the jacking mechanism is to provide pressure at the top of the drill rod while not affecting the rotation of the drill rod. Thus, the drill rod is pressed down under the action of the pressure, and the lead screw and nut transmission mechanism drives the drill rod to rotate. The two forces drive the drill rod to complete drilling.
[0023] Or a motor drives a driving wheel connected by a transmission belt, and then each driven wheel rotates. The drill rods are installed inside the main shafts of each driven wheel through threads. In this example, the driven wheels and the main shafts of the driven wheels rotate synchronously.
[0024] During the whole process, each drill rod is driven by the transmission belt to achieve the synchronous rotation of multiple drill rods, and then achieve synchronous drilling and the consistency of the relative angles.
[0025] More specifically, the lead screw nut type transmission mechanism includes a motor, an output shaft driven by the motor, and a drill pipe sleeved inside the output shaft, with a thread fit formed between the drill pipe and the output shaft.
[0026] The power source of the transmission belt can be from the motor or from another externally installed motor, mainly configured on-site.
[0027] A clamping groove 9 for fixing the stretching device is provided on the acoustic emission receiving device group and the acoustic emission excitation device group. The stretching device includes an adjusting rod 14, with rotating nuts 15 sleeved on both sides of the adjusting rod 14. Different-handed screws are fitted inside the rotating nuts 15, and clamping rings that are in the same form and position as the clamping groove 9 are provided at the ends of the screws. After the drill pipe is in place, the stretching device works to finely adjust the positions of the acoustic emission receiving device group and the acoustic emission excitation device group, further improving the coupling effect of the inductor and the accuracy of the test.
[0028] The clamping groove 9 is a rotary groove, with a positioning ring provided inside the rotary groove, and a rubber strip for increasing friction is laid inside the rotary groove. During the working process of the stretching device, first, clamping is achieved at both ends of the clamping groove. Using the adjusting rod as one of the force application points, the rotating nut 15 is rotated, and the displacement of the screws on both sides is achieved through the thread fit, thereby completing the adjustment. During the adjustment process, the rotational freedom of the screws is restricted by the friction between the clamping groove and the screws. The rubber strip increases the friction between the screws and the clamping groove.
[0029] A transverse limiting plate is slidably sleeved on the support shoe 1, and a guiding hole for facilitating the passing of the cutting cylinder is provided on the transverse limiting plate; a circumferential limiting plate is also movably sleeved on the transverse limiting plate. The cutting cylinder above the support shoe 1 passes through the circumferential limiting plate and drills into the rock formation. At the same time, an acoustic emission receiving device is sleeved inside the cutting cylinder above the support shoe 1, and a positioning pin type connection that is convenient for disassembly and assembly is provided between the circumferential limiting plate and the transverse limiting plate. The function of the circumferential limiting ring is to assist in supporting the drill pipe.
[0030] A rotating positioning ring is provided outside the guiding hole. An auxiliary pulling rope with a length of 1 meter or 2 meters is wound around the rotating positioning ring. The inner diameter of the rotating positioning ring is the same as the outer diameter of the cutting rod 5, and a transitional fit connection is formed between the rotating positioning ring and the cutting rod 5. The power mechanism is a belt drive mechanism. The working process of the rotating positioning ring is as follows. First, when not working, the auxiliary pulling rope is wound and fixed by itself. When starting to work, it is sleeved on the end of the cutting rod. The outer diameter of the rotating positioning ring is smaller than the inner diameter of the cutting cylinder, that is, it does not affect the displacement of the cutting rod and can move together with the end of the cutting rod towards the drilling depth. During the movement, the auxiliary pulling rope detects the insertion depth of the cutting rod to realize the axial positioning of the acoustic emission receiving device. That is, when the auxiliary pulling rope is only 2 meters long, the tension of the pulling rope proves that the cutting rod has penetrated 2 meters. A mark is provided at the 1-meter position of the corresponding auxiliary pulling rope, and it can be determined whether the depth of 1 meter is reached by whether the mark is submerged in the cutting cylinder.
[0031] It also includes a fixing mechanism for fixing the acoustic emission excitation device group and the acoustic emission receiving device group on the lining. The fixing mechanism includes a friction wheel 6 installed on the hydraulic component fixing block. A screw hole for passing a set screw is provided in the middle of the friction wheel 6. A transfer wheel 7 for transmitting power is provided between the friction wheel 6 and the transmission mechanism; a fork 8-type switch for driving the conversion of its working position is installed on the transfer wheel 7; the set screw is preset in the screw hole, and the top forms a screw-nut fit with the corresponding electric mechanism. The function of this device is that during the equipment fixing stage, before the drill rod is fixed, the position of the transfer wheel is adjusted to lead a section of power in the power source to drive the friction wheel to rotate. Further, the friction wheel uses the principle of thread fit to fix the set screw on the rock mass or the lining. At this time, the drilling part of the drill rod in the drilling mechanism rotates idly. When fixed, the position of the transfer wheel is adjusted to disconnect the power connection, and the transmission belt can continue to complete the installation of the drill rod.
[0032] An evaluation method for monitoring and evaluating the damage degree of the surrounding rock around the TBM shoe through the change of rock mass velocity mainly has the following steps: Step 1, according to the current TBM tunneling situation, estimate the step-changing distance of the TBM at the shield tail position later, and clarify that the step-changing distance is 1 step or half a step; Step 2, according to the step-changing distance determined in Step 1, combined with the size of the shoe plate, set excitation holes and monitoring holes at positions 8 to 12 cm outward on both sides. The excitation holes are on one side of the shoe plate, and the receiving detection holes are on the other side of the shoe plate. The circumferential distance interval between the single-sided holes is more than 1 meter; Step 3, drill holes. Use the L1 area bolt drill to drill excitation and monitoring holes, and record the positions and horizontal angles of the drill holes at the same time to ensure that the corresponding hole positions and horizontal angles on both sides of the shoe plate are the same. The drilling depth is 1.8 to 2 m; Step 4: The embedding of the sensors is carried out after the retraction of the support shoe 1. The acoustic emission sensors of the drilling mechanism are installed in the hole, with a sensor spacing of 10 cm. The embedding starts from a depth of 2 m in the hole for 0.5 m. Each single hole requires 12 to 16 sensors; on the left and right sides of the support shoe 1 are the excitation and receiving acoustic emission sensors respectively. The sensors in the left hole are placed in the 3 o'clock direction, and the right ones are placed in the 9 o'clock direction. With the help of the stretching device, the sensors are well coupled with the rock wall; at the same time, the three-dimensional positions of the excitation and receiving acoustic wave sensors are calculated. Step 5: After moving the support shoe 1 to the new support shoe position, it extends towards the surrounding rock wall and is tightened. During this process, the acoustic wave signals of the acoustic emission excitation sensors are alternately excited at an interval of 5 seconds, and records are made simultaneously on the receiving side. Step 6: Conduct real-time processing of the monitoring, calculate and record the wave velocities between different excitation and receiving points. Step 7: Plot the graph of wave velocity versus time for the acoustic waves of different paths. Step 8: Give early warnings for the support shoe pressure or the tunneling speed according to the wave velocity change. For example, give an early warning when the acoustic wave velocity change exceeds 5%, and a collapse is inevitable when it exceeds 10%.
[0033] According to relevant test data, taking granite as an example, when the initial velocity is about 4000, a 20% change in velocity is judged as the limit; when the initial velocity is about 5000, a 15% change is the limit; when the initial velocity is 6000, a 10% change is the limit. The above is an empirical judgment and needs to be adjusted in combination with the on-site situation.
[0034] That is, when exceeding the limit, it can be determined that the bearing capacity of the surrounding rock under pressure is insufficient.
[0035] That is, below 4000, it is judged according to 20%, above 6000 according to 10%, and between 4000 - 6000, it can be judged linearly from 20% to 10%. Embodiment 2
[0036] The structures of the friction wheel 6 and the transfer wheel 7 are replaced as follows: The fixing mechanism includes a friction wheel 6 installed on the hydraulic component fixing block. A sleeve is provided in the middle of the friction wheel 6, and a screw hole for the set screw to pass through is provided in the sleeve. A sliding key connection is provided between the friction wheel 6 and the sleeve. When the friction wheel 6 is at one end of the sliding key connection, the friction wheel 6 forms power transmission with the transmission belt. In this embodiment, the transfer wheel is removed. The friction wheel has two working positions. When it does not friction with the transmission belt, there is no power transmission. When it is adjusted on the sliding key to cooperate with the transmission belt, power is led out to fix the set screw.
[0037] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A detection device for monitoring and evaluating the stability of surrounding rock around the TBM support shoe by using the change of rock mass velocity, characterized in that: It includes an acoustic emission excitation device group, an acoustic emission receiving device group, a stretching device for pulling the distance between the acoustic emission excitation device group and the acoustic emission receiving device group, a jacking mechanism for driving the acoustic emission excitation device group and the acoustic emission receiving device group into the rock formation, and an information processing device. The input end of the information processing device is connected to the acoustic emission excitation device group and the acoustic emission receiving device group; the output end of the information processing device is connected to an alarm and a shoe controller. Among them, with the shield cutter head in the front and the TBM tail in the rear, the acoustic emission excitation device group is in front of the shoe (1), and the acoustic emission receiving device group is behind the shoe (1); at least three AE receiving sensors corresponding in shape and position are equidistantly arranged on each acoustic emission receiving device group; the acoustic emission excitation device group further includes a power input device, a transmission mechanism for transmitting power, and at least three synchronous power output devices. A plug-in drill rod is installed on the power output device through threaded connection, and at least 3 AE excitation sensors are arranged on the plug-in drill rod; the acoustic emission receiving device group includes a power input device, a transmission mechanism for transmitting power, and at least three power output devices. A plug-in drill rod is installed on the power output device through threaded connection, and at least 3 AE receiving sensors are arranged on the plug-in drill rod.
2. The detection device for monitoring and evaluating the stability of surrounding rock around the TBM shoe using the change in rock mass velocity as claimed in claim 1, wherein: The jacking mechanism includes a nut driven by a power source and a hydraulic mechanism for providing pressure to the drill rod in the nut. The hydraulic mechanism includes a pressure rod (11), and a collar (10) is nested and installed in the pressure rod (11). The inner diameter of the collar (10) is larger than the outer diameter of the drill rod.
3. The detection device for monitoring and evaluating the stability of the surrounding rock around the TBM support shoe by using the change in rock mass velocity as claimed in claim 2, wherein: The acoustic emission excitation device group and the acoustic emission receiving device group are provided with clamping grooves (9) for fixing the stretching device. The stretching device includes an adjusting rod (14). Rotating nuts (15) are sleeved on both sides of the adjusting rod (14). Screws with different helix directions are fitted in the rotating nuts (15). A clamping ring with the same shape and position as the clamping groove (9) is provided at the end of the screw.
4. The detection device for monitoring and evaluating the stability of surrounding rock around the TBM shoe using the change in rock mass velocity as claimed in claim 3, wherein: The clamping groove (9) is a rotary groove. A positioning ring is provided in the rotary groove, and a rubber strip for increasing friction is laid in the rotary groove.
5. The detection device for monitoring and evaluating the stability of surrounding rock around the TBM support shoe by using the change in rock mass velocity according to claim 4, characterized in that: A rotary positioning ring is provided outside the guiding hole. An auxiliary pulling rope with a length of 1 meter or 2 meters is wound on the rotary positioning ring. The inner diameter of the rotary positioning ring is the same as the outer diameter of the plug-in rod (5). A transitional fit connection is formed between the rotary positioning ring and the plug-in rod (5).
6. The detection device for monitoring and evaluating the stability of surrounding rock around the TBM shoe using the change in rock mass velocity as described in claim 1, characterized in that: The power mechanism is a belt transmission mechanism.
7. The detection device for monitoring and evaluating the stability of surrounding rock around the TBM shoe using the change in rock mass velocity according to claim 1, characterized in that: It also includes a fixing mechanism for fixing the acoustic emission excitation device group and the acoustic emission receiving device group on the lining. The fixing mechanism includes a friction wheel (6) installed on a hydraulic component fixing block. A screw hole for passing a set screw is provided in the middle of the friction wheel (6). An intermediate wheel (7) for transmitting power is provided between the friction wheel (6) and the transmission mechanism; a fork (8)-type switch for driving the working position conversion is installed on the intermediate wheel (7); the set screw is preset in the screw hole, and the top forms a lead screw-nut fit with the corresponding electric mechanism.
8. The detection device for monitoring and evaluating the stability of surrounding rock around the TBM support shoe by using the change in rock mass velocity as claimed in claim 7, characterized in that: The structures of the friction wheel (6) and the transfer wheel (7) are replaced such that the fixing mechanism includes a friction wheel (6) mounted on a hydraulic component fixing block. A sleeve is provided in the middle of the friction wheel (6), and a screw hole for a set screw to pass through is provided in the sleeve. A sliding key connection is provided between the friction wheel (6) and the sleeve. When the friction wheel (6) is at one end of the sliding key connection, the friction wheel (6) forms power transmission with the transmission belt.
9. An evaluation method for monitoring and evaluating the damage degree of surrounding rock around the TBM shoe through the change of rock mass velocity, mainly including the following steps: Step 1, according to the current TBM tunneling situation, estimate the step-changing distance of the TBM at the shield tail position in the future, and clarify that the step-changing distance is 1 step or half a step; Step 2, according to the step-changing distance determined in Step 1, combined with the size of the shoe plate, set excitation holes and monitoring holes at positions 8 to 12 cm outward on both sides. The excitation hole is on one side of the shoe plate, and the receiving detection hole is on the other side of the shoe plate. The circumferential distance interval between single-side holes is more than 1 m; Step 3, drill holes. Use the L1 area bolt drill to drill excitation and monitoring holes, and record the positions and horizontal angles of the drill holes at the same time, ensuring that the corresponding hole positions and horizontal angles of the left and right sides of the shoe plate are the same. The drilling depth is 1.8 to 2 m; Step 4, the embedding of the sensors is carried out after retracting the shoe (1). Use the drilling mechanism acoustic emission sensors to be installed in the holes. The distance between the sensors is 10 cm. Start embedding from 2 m deep in the hole at 0.5 m. 12 to 16 sensors are required for a single hole; on the left and right sides of the shoe (1) are respectively the excitation and receiving acoustic emission sensors. The sensors in the left hole are placed in the 3 o'clock direction, and the right side is placed in the 9 o'clock direction, and the sensors are coupled well with the rock wall by means of a stretching device; at the same time, calculate the three-dimensional positions of the excitation and receiving acoustic wave sensors; Step 5, after moving the shoe (1) to a new shoe position, extend it towards the surrounding rock wall and tighten it. During this process, alternately excite the acoustic wave signals of the acoustic emission excitation sensors at an interval of 5 seconds, and record at the receiving side at the same time; Step 6, perform real-time processing on the monitoring, calculate and record the wave velocities between different excitation and receiving points; Step 7, draw a graph of the wave velocity changing with time for the acoustic waves of different paths; Step 8, give an early warning about the pressure or tunneling speed of the shoe (1) according to the change of the wave velocity. For example, if the change of the acoustic wave velocity exceeds 5%, an early warning is given, and if it exceeds 10%, collapse is inevitable.