TBM and rock burst prevention method

Abstract

The present application belongs to the technical field of tunneling equipment or method, and specifically provides a TBM and a rock burst prevention method. The rock burst prevention method comprises the following steps: sending an electrocracking generator into a stress release hole in a front rock mass, generating a liquid-electric effect in the hole, forming a cracking wave, making the target rock mass produce a crack, and continuing until the crack range approaches the target crack range or a set range; then, a cracking agent with a self-expanding effect is introduced into the stress release hole, the cracking agent enters the crack and flows to the end of the crack, and after the cracking agent expands, secondary cracking is performed on the end of the crack to meet the stress release requirement. The TBM is provided with a rock burst prevention device for realizing the above rock burst prevention method. The present application combines electrocracking and expansion agent cracking, uses the high-efficiency cracking effect of electrocracking to initially make the rock mass produce a crack, uses the advantage that the expansion agent can flow to the end of the crack to perform secondary cracking on the end of the crack, realizes accurate control of the cracking range, and can accurately prevent rock burst.

Description

Technical Field

[0001] This invention belongs to the technical field of tunneling equipment or methods, and in particular relates to a TBM and a method for preventing rockbursts. Background Technology

[0002] When TBMs are used in deep tunnel engineering projects such as mines and hydropower plants, the sudden release of high strain energy accumulated in the rock mass can often lead to rockburst disasters, damaging equipment and causing casualties in severe cases. Methods for preventing rockburst disasters during TBM construction generally include reducing the tunneling speed, active energy release, and passive support. Active energy release is the most cost-effective method and can release rock mass stress in advance, making it the mainstream method for rockburst prevention.

[0003] Traditional active energy release methods involve drilling pre-stress relief holes and then inserting explosives into them, essentially using drill-and-blast to break up rock and release rock stress. However, the blasting fracturing range of the drill-and-blast method is difficult to control, resulting in poor controllability of surrounding rock disturbance and, in severe cases, secondary disasters such as landslides. Therefore, its practical application effect is poor.

[0004] In recent years, with the deepening research on the rockburst generation mechanism and novel fracture-making rock-breaking methods, existing technologies have seen research on using TBMs equipped with novel fracture-making rock-breaking devices to handle rockbursts. The applicant's invention patent (CN113217009B) provides a microwave-gain CO2 phase change pressure relief method for preventing rockbursts. It utilizes the phase change of microwaves and CO2 to create fractures in stress relief holes, releasing rock mass energy. However, the CO2 expansion rate is extremely fast, making it difficult to reach the fracture end, resulting in poor mesh formation. Patent application CN106761796A (publication date: 2017.05.31) discloses a microwave stress relief device on a TBM for rockburst prevention. This device uses microwaves alone to fracture the rock and release rock mass stress. However, microwaves have different sensitivities to rock masses with different mineral compositions, leading to incomplete stress release due to incomplete fracture development in practical applications. Patent document CN215676714U (publication date: January 28, 2022) discloses an expansion rock-breaking system for preventing rockbursts in tunnels. This system uses expansion liquid material injected into the expansion hole to break the rock using expansion pressure. However, in reality, the effect of expansion material on hard rock is limited. Patent document CN111706390B (publication date: March 1, 2022) discloses a method for eliminating rockbursts. This method requires filling the borehole with water and using a high-voltage electric pulse device to discharge and heat the water, causing the water to heat up, vaporize, and expand, thus cracking the high-stress areas of the rock mass and releasing stress. However, this method is cumbersome and also suffers from the problem of difficulty in precisely controlling the cracking process at the end.

[0005] Analysis shows that the above-mentioned new methods for dealing with rockbursts all have the problem of poor effectiveness. In particular, it is difficult to accurately control the extent of the crack tip, which can easily lead to incomplete or excessive stress release in the rock mass, affecting the stability of the surrounding rock. Summary of the Invention

[0006] The purpose of this invention is to provide a rockburst prevention method to solve the technical problem of difficulty in accurately controlling the fracture range when dealing with rockbursts in the prior art. Another purpose of this invention is to provide a TBM (Tower Builder) that implements the above-mentioned rockburst prevention method to solve the same technical problem.

[0007] To achieve the above objectives, the technical solution of the rockburst prevention method provided by this invention is as follows:

[0008] A rockburst prevention method involves inserting an electro-fracturing generator into a stress relief hole in the rock mass ahead. The generator produces a hydraulic-electric effect within the hole, forming a fracturing wave that causes fissures in the target rock mass until the fissure range approaches the target or predetermined range. Then, a self-expanding fracturing agent is introduced into the stress relief hole. The agent enters the fissure, flows towards the fissure tip, and after expanding, performs secondary fracturing at the fissure tip, thus achieving the required stress relief.

[0009] The beneficial effects are as follows: This invention, based on the concept of electro-fracturing and expansion agent-induced fracturing, provides a method for preventing rockbursts by combining the two. When encountering rockburst-prone strata during construction, after drilling stress relief holes, an electro-fracturing generator is inserted into the hole. When the generator is energized, and the energy reaches the breakdown energy of the metal wire, a hydro-hydraulic effect occurs within the hole, converting electrical energy into shock wave energy, forming an electrical pulse impact force that induces internal fractures in the rock mass. Then, a fracturing agent is injected into the fractures. Utilizing the expansion effect of the fracturing agent, secondary fracturing occurs at the fracture ends, forming a fracture network, thus achieving a thorough stress release. Compared to existing technologies, this invention does not employ a single fracturing method. It combines electro-fracturing and expansion agent-induced fracturing, utilizing the highly efficient fracturing effect of electro-fracturing to initially induce fractures in the rock mass, and leveraging the advantage of the expansion agent flowing into the fracture ends for secondary fracturing at the fracture ends. This achieves precise control of the fracturing range, thereby enabling precise prevention and control of rockbursts.

[0010] As a further improvement, a fracturing agent is introduced into the stress relief hole using a fracturing tube connected to an electro-fracturing generator.

[0011] The beneficial effect is that by integrating the fracturing tube and the electro-fracturing generator into one unit, the fracturing tube can be simultaneously inserted into the borehole during the electro-fracturing process, thus improving work efficiency.

[0012] As a further improvement, a high-voltage electric pulse drill bit coaxially connected to the electro-cracking generator is used to drill stress relief holes.

[0013] The beneficial effects are: by integrating the drill bit and the electro-fracture generator into one unit, the electro-fracture generator can be simultaneously inserted into the hole during drilling, allowing for direct electro-fracture operations and improving work efficiency.

[0014] As a further improvement, the depth of the stress relief hole is 2-3 times the diameter of the excavation section.

[0015] The beneficial effect is that the requirements for pre-stress release have been basically met within this range.

[0016] As a further improvement, an acoustic sensor is used to detect the extent of fracture development during electro-induced fracturing.

[0017] The beneficial effects are: the crack range can be measured in real time, and the power of the electro-cracking generator and the ratio of the cracking agent expansion component can be adjusted according to the crack range, making the control of the cracking range more precise.

[0018] As a further improvement, the concentration of the expanding component in the crack initiator is determined according to the range of crack initiation required.

[0019] The beneficial effect is that it further improves the accuracy of the crack initiation range.

[0020] To achieve the above objectives, the technical solution for TBM provided by this invention is as follows:

[0021] TBM includes a rockburst prevention device, which includes a drilling device and a fracturing device. The fracturing device is connected to a propulsion drive device. The fracturing device includes an electro-fracturing generator, which includes a housing. The housing has a fracturing wave window, and the window has a positive electrode, a negative electrode, and a metal wire connected to the positive electrode and the negative electrode. The fracturing device also includes a fracturing tube, which has a fracturing agent flow channel and a fracturing agent outlet inside.

[0022] The beneficial effects are as follows: This invention improves upon existing rockburst prevention devices mounted on TBMs. When dealing with rockbursts, stress relief holes are first drilled at the working face. A fracturing device is then inserted into the hole under the action of a propulsion drive. Electricity is supplied to the electro-fracturing generator. When the energy reaches the breakdown energy of the metal wire, a hydro-hydraulic effect occurs within the hole, converting electrical energy into shock wave energy, forming an electrical pulse impact force that induces internal fractures in the rock mass. When approaching the target fracture area, electro-fracturing is stopped, and a certain amount of fracturing agent is injected into the fracture through the fracturing tube. The fracturing agent flows to the fracture tip, promoting secondary development at the fracture tip, ensuring sufficient fracturing of the rock mass, and controlling the fracture within the target fracture area. Compared with existing technologies, this invention achieves precise control of the fracturing range through the coordinated operation of the electro-fracturing generator and the fracturing tube, thus enabling precise handling of rockbursts.

[0023] As a further improvement, the fracturing device is connected to the electro-fracturing generator and has an internal cable that is electrically connected to the electro-fracturing generator.

[0024] The beneficial effects are: integrating the fracturing tube and the electro-fracturing generator into one unit allows for direct injection of fracturing agent into the borehole after electro-fracturing is completed, eliminating the need to remove the electro-fracturing generator from the borehole first, thus improving work efficiency. Furthermore, the electro-fracturing generator can be positioned at the front, requiring only a cable connection to the fracturing tube, and it also facilitates connection of the fracturing tube to the fracturing agent storage pump.

[0025] As a further improvement, the fracturing tube is also connected to a rigid cable cylinder, which has a double-layer structure with an inner layer containing a cable and an outer layer forming a fracturing agent flow channel. The cable is electrically connected to the cable inside the fracturing tube, and the fracturing agent flow channel is connected to the fracturing agent flow channel of the fracturing tube.

[0026] The beneficial effects are: when dealing with rockbursts in deeper stress relief holes, the length of the rigid cable drum can be increased to meet the power and liquid supply requirements for the electro-fracture generator and fracturing tube, thus improving the ease of use.

[0027] As a further improvement, the rigid cable cylinder is provided with detachable connection structures that cooperate with each other at both ends.

[0028] The beneficial effect is that when dealing with rockbursts in deeper stress relief holes, the length of the rigid cable can be increased by increasing the number of rigid cable cans, thus eliminating the need to deploy a single long cable can, which improves mobility.

[0029] As a further improvement, the electro-fracture generator is also connected to a high-voltage electric pulse drill bit. The high-voltage electric pulse drill bit, the electro-fracture generator, the fracturing tube, and the rigid cable cylinder are coaxially connected, and the fracturing device forms the drilling device.

[0030] The beneficial effect is that the fracturing device integrates drilling, fracturing, and secondary fracture development into one unit, and can directly carry out fracturing work after the front-end drilling is in place, which greatly improves the efficiency of handling rockbursts.

[0031] As a further improvement, the high-voltage electric pulse drill bit and the electro-fracturing generator are detachably connected, and the fracturing tube and the rigid cable drum are detachably connected.

[0032] The beneficial effect is that the high-voltage electric pulse drill bit can be selected according to the site conditions. If the site already has the conditions for drilling, the high-voltage electric pulse drill bit can be removed to save energy.

[0033] As a further improvement, the detachable connection structures between the high-voltage electric pulse drill bit and the electro-fracturing generator, between the fracturing tube and the rigid cable drum, and at both ends of the rigid cable drum are all threaded connections.

[0034] The beneficial effect is that if the fracturing device is installed on a drilling rig with a rotary drive, the rotational power of the drilling rig can drive the rotation of each part to automatically complete the connection, thus improving the installation efficiency.

[0035] As a further improvement, the fracturing device also includes a fracture detection system, which includes an acoustic sensor.

[0036] The beneficial effects are: the crack range can be measured in real time, and the power of the electro-cracking generator and the ratio of the cracking agent expansion component can be adjusted according to the crack range, making the control of the cracking range more precise. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the working state of the TBM in Example 1 of the present invention for preventing rockbursts;

[0038] Figure 2 This is a schematic diagram of the rockburst prevention device in TBM Embodiment 1 of the present invention;

[0039] Figure 3 This is a rear view of the rockburst prevention device in TBM Embodiment 1 of the present invention;

[0040] Figure 4 This is a schematic diagram of the fracturing device in the TBM embodiment 1 of the present invention;

[0041] Figure 5 for Figure 4 Schematic diagram of the structure of a medium- and high-voltage electric pulse drill bit;

[0042] Figure 6 for Figure 4 A schematic diagram of the structure of a medium-voltage cracking generator;

[0043] Figure 7 for Figure 4 Schematic diagram of the structure of the rupture tube;

[0044] Figure 8 for Figure 4 Schematic diagram of the structure of the cable drum;

[0045] Figure 9 A schematic diagram of the rock mass fracture structure after fracturing by an electro-fracture generator;

[0046] Figure 10 A schematic diagram of the rock mass fracture network structure after secondary fracturing by a fracturing agent.

[0047] Figure 11 A schematic diagram of the structure of the fracture ring formed after the fracture is completed.

[0048] Explanation of reference numerals in the attached figures:

[0049] 100. Cutterhead; 200. Shield body; 300. Fracturing device; 400. Fracturing device drive system; 500. High-voltage power supply; 600. Fracturing agent storage tank; 700. Normal rock formation; 800. Rockburst-prone rock formation; 900. Moving frame; 301. High-voltage electric pulse drill bit; 302. Electro-fracturing generator; 303. Fracturing tube; 304. Cable drum; 305. Thread; 306. Threaded hole; 3011. High-voltage electric pulse drill bit negative electrode; 3012. High-voltage electric pulse drill bit positive electrode. ; 3021, fracturing wave window; 3022, positive electrode of electro-fracturing generator; 3023, metal wire; 3024, negative electrode of electro-fracturing generator; 3031, fracturing agent outlet; 3041, cable channel; 3042, fracturing agent channel; 401, propulsion drive device; 402, rotation drive device; 403, propulsion frame; 801, stress relief hole; 802, electro-fracturing fracture; 803, expansion fracturing fracture; 804, fracture ring; 901, rack; 902, motor. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0051] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0052] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, terms such as "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the process or method that includes said element.

[0053] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0054] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "provided with" should be interpreted broadly. For example, the object "provided with" can be a part of the main body, or it can be separately arranged from the main body and connected to the main body. This connection can be a detachable connection or a non-detachable connection. Those skilled in the art can understand the specific meaning of the above terms in this invention through specific circumstances.

[0055] The present invention will be further described in detail below with reference to the embodiments.

[0056] Specific embodiment 1 of the TBM provided by this invention:

[0057] The TBM provided in this embodiment is as follows: Figure 1 As shown, the system includes the main unit and its supporting systems. The main unit includes a cutterhead 100, a shield 200, and a rockburst prevention device. The structure of the cutterhead 100, the shield 200, and other parts of the main unit is the same as that of a conventional TBM, and will not be described here.

[0058] The rockburst prevention device includes a fracturing device 300 and a fracturing device drive system 400, such as Figure 2 As shown, the fracturing device 300 is connected to the fracturing device drive system 400. The fracturing device drive system 400 is used to drive the fracturing device 300 forward. Specifically, it includes a propulsion drive device 401, a rotation drive device 402, and a propulsion frame 403. The fracturing device 300 is connected to the rotation drive device 402. The propulsion drive device 401 pushes the fracturing device 300 and the rotation drive device 402 to slide forward along the propulsion frame 403.

[0059] In this embodiment, the rockburst prevention device is connected to the main beam of the TBM via a movable frame 900 and can move along the movable frame 900. Specifically, the movable frame 900 has an arc-shaped structure and is equipped with an arc-shaped rack 901. The push frame 403 is equipped with a gear that meshes with the arc-shaped rack 901. The movable frame 900 is also equipped with a drive device for driving the push frame 403 to move along the arc-shaped rack 901. Specifically, in this embodiment, the drive device is a motor 902, but it can also be a hydraulic motor.

[0060] like Figure 3As shown, the rockburst prevention device in this embodiment can move 90° circumferentially along the movable frame to meet the stress treatment requirements at different positions on the arc apex. In this embodiment, the rockburst prevention device can move within a circumferential range of 120 degrees.

[0061] like Figure 4 As shown, the fracturing device 300 includes a high-voltage electric pulse drill bit 301, an electric fracturing generator 302, a fracturing tube 303, and a cable drum 304. These parts are connected front and rear by threads, and the quantity of the high-voltage electric pulse drill bit 301 and the cable drum 304 can be selected according to the working conditions. Figure 5 As shown, the high-voltage electric pulse drill bit 301 includes a high-voltage electric pulse drill bit negative electrode 3011 and a high-voltage electric pulse drill bit positive electrode 3012, and a thread 305 is provided at the rear end. The discharge rock breaking principle of the high-voltage electric pulse drill bit 301 is existing technology and will not be described in detail here.

[0062] like Figure 6 As shown, the electro-fracturing generator 302 includes a housing with a fracturing wave window 3021. The fracturing wave window 3021 contains a fracturing wave generating structure, specifically including a positive electrode 3022, a negative electrode 3024, and a metal wire 3023 connected to the positive and negative electrodes. When the positive and negative electrodes are energized and the breakdown energy of the metal wire 3023 is reached, the metal wire 3023 will undergo a hydroelectric effect in a humid environment. This hydroelectric effect converts high-power electrical energy into shock wave energy at an extremely high speed, which is then applied to the rock mass through the fracturing wave window 3021. When the fracturing wave energy exceeds the fatigue strength of the rock mass, it will cause cracks to form inside the rock mass. In this embodiment, the pressure range of the fracturing wave output energy is 0-120 MPa, which basically meets the fracturing requirements of different grades of hard rock. The front end of the housing of the electro-cracking generator 302 is provided with a threaded hole 306, which can be quickly connected to the thread 305 of the high-voltage electric pulse drill bit 301 through the threaded hole 306; the rear end of the housing is provided with a thread 305.

[0063] Fracturing pipe 303 is a dedicated pipeline for discharging fracturing agent, such as... Figure 7 As shown, a fracturing agent outlet 3031 is provided on its outer periphery. The fracturing agent is a statically self-expanding liquid material, specifically an HSCA expander or a thermally expanding agent containing ferric oxide in its formulation. A threaded hole 306 is provided at its front end, and it is connected to the housing of the electro-fracturing generator 302 through the threaded hole 306. In this embodiment, a cable is also provided inside the fracturing tube 303. Specifically, the fracturing tube 303 has a double-layer structure; the outer layer is a fracturing agent flow channel, and the inner layer contains a cable, which is electrically connected to the electro-fracturing generator 302 to supply power to the electro-fracturing generator 302.

[0064] Cable drum 304 also has a double-layer structure, which includes a rigid shell, such as... Figure 8As shown, the device includes an inner cable channel 3041 containing a cable that is electrically connected to a cable inside the fracturing tube 303, supplying power to the fracturing device 300. The outer layer is a fracturing agent channel 3042, which communicates with the fracturing agent flow channel of the fracturing tube 303 and supplies fracturing agent to the fracturing tube. The front end of the cable reel 304 has a threaded hole for connection with the threaded end 305 of the rear end of the fracturing tube 303, and the rear end has a thread for connection with another cable reel 304. In other words, both ends of the cable reel 304 are mutually mating, detachable threaded structures.

[0065] In this embodiment, the fracturing device 300 is also equipped with a fracture detection system, which includes an acoustic sensor (not shown in the figure). Specifically, the acoustic sensor can be arranged in the electro-fracturing generator 302 or the fracturing tube 303, and the range and depth of the fracture can be determined based on the feedback of the acoustic signal.

[0066] It should be noted that the threads 305 and threaded holes 306 in the above-mentioned parts are interchangeable, and the power supply to the high-voltage electric pulse drill bit 301 and the electro-fracturing generator 302 can be controlled independently. In addition, the water content of conventional rock masses is generally sufficient to meet the conditions for the generation of the electrohydraulic effect. If the water content of the rock mass is too low, water can be introduced into the hole through the fracturing pipe 303 or other water supply pipes.

[0067] In this embodiment, the TBM is also equipped with a high-voltage power supply 500 for supplying power to the fracturing device 300 and a fracturing agent storage tank 600 for supplying fracturing agent to the fracturing device 300.

[0068] This embodiment works as follows: Figure 1 and Figures 8-11 As shown, it mainly includes the following steps:

[0069] In the first step, after determining the location of the rock stratum 800 prone to rock blasting ahead, the TBM stops its forward excavation. The high-voltage power supply 500 and the fracturing agent storage tank 600 are connected to the fracturing device 300. The fracturing device drive system 400 propels the fracturing device 300 forward from the working face through the normal rock stratum 700. The high-voltage electric pulse drill bit 301 drills forward, creating a stress relief hole 801. In this step, the drilling depth of the stress relief hole 801 is 2-3 times the diameter of the excavation section, which basically meets the stress relief requirements of the preceding rock stratum.

[0070] In the second step, during the drilling process of the high-voltage electric pulse drill bit 301, the electro-fracture generator 302 simultaneously enters the stress relief hole. At this time, the electro-fracture generator 302 is energized, generating a hydraulic-electric effect in the stress relief hole, forming a fracturing wave, which causes the target rock mass to generate an electro-fracture 802. At this time, the fracturing device 300 can be rotated by the rotary drive device 402 to achieve circumferential fracturing. After each discharge fracturing, the depth and range of the electro-fracture 802 are detected by the fracturing detection system until it approaches the fracturing range required to deal with rockburst or the preset electro-fracture fracturing range (for example, releasing rock stress requires a fracturing diameter of 1m, and the electro-fracture fracturing is stopped when the range is 0.9m, or the preset electro-fracture fracturing range is 0.9m).

[0071] In the third step, during the drilling process of the high-voltage electric pulse drill bit 301, the fracturing tube 303 is simultaneously introduced into the stress relief hole. At this time, a fracturing agent is introduced into the fracturing tube 303. The concentration of the expansion component in the fracturing agent is determined according to the range of fracturing required. The fracturing agent seeps out from the fracturing agent outlet 3031 and flows into the electro-fracturing fissure 802. Because the fracturing agent has good fluidity, it can flow into the end of the electro-fracturing fissure 802. After a certain period of time, the fracturing agent expands on its own, promoting the secondary development of the end of the electro-fracturing fissure 802 and generating an expansion fracturing fissure 803. At this time, the fracturing fissure range required for rockburst stress relief treatment is completed, generating a fracture ring 804, thus achieving the prevention and control of rockburst.

[0072] This embodiment does not employ a single fracturing method. It has the advantages of high efficiency of electro-fracturing and stable fracturing by fracturing agents. The initial fracturing is completed by electro-fracturing, and then the fracturing agents expand to induce secondary fracturing, especially at the fracturing ends where electro-fracturing energy is difficult to reach. The fracturing agents can act directly on the fracturing ends, causing the fracturing to form a network. This achieves precise control of the fracturing range and thus precise prevention and control of rockbursts.

[0073] This embodiment also integrates drilling, electro-fracture, expansion fracturing, and fracture range detection into one unit. That is, the fracturing device simultaneously forms a drilling device, which greatly improves efficiency. The next step can begin immediately after each step is completed. At the same time, the fracture range can be detected in real time by an acoustic sensor, which further improves the accuracy of fracture treatment.

[0074] In this embodiment, the various parts of the fracturing device 300 are coaxially and detachably connected via a threaded connection structure. This facilitates matching different structures to different working conditions. For example, if the advanced drilling rig mounted on the TBM has already completed drilling the stress relief hole, the high-voltage electric pulse drill bit 301 may not be required. Moreover, if the stress relief hole is deep, a cable cylinder 304 can be connected to the rear end of the fracturing device 300 to increase the length of the fracturing device, thereby adapting to more situations and avoiding an excessively long fracturing device, which also facilitates layout. In addition, since the various parts are connected by threads, they can be automatically fastened together under the driving action of the rotary drive device 402, resulting in high efficiency.

[0075] The specific embodiment 2 of the TBM provided by this invention differs from embodiment 1 mainly in that: in embodiment 1, the fracturing device 300 integrates drilling and fracturing. In this embodiment, the high-voltage electric pulse drill bit and cable drum are not included. The TBM is equipped with a pre-drilling rig or other drilling device. During use, the pre-drilling rig is used to drill stress relief holes. Each part is a separate structure. The fracturing device includes its own independent electric fracturing generator and fracturing tube. During use, both are respectively sent into the stress relief holes.

[0076] The specific embodiment 3 of the TBM provided by this invention differs from embodiment 1 mainly in that: in embodiment 1, the fracturing device 300 integrates an acoustic sensor to detect fractures. In this embodiment, the fracture detection system is not included. Given prior geological data of the rock mass, the electro-fracturing power and the number of electro-fracturing cycles can be adjusted based on laboratory data, stopping when the target fracture is approached. Then, an expanding fracturing agent is injected into the fracture through the fracturing tube, which also ensures the fracturing range and achieves the rockburst stress release effect.

[0077] The specific embodiment 4 of the TBM provided by this invention differs from embodiment 1 mainly in that: in embodiment 1, the parts are detachably connected via a threaded structure. In this embodiment, the parts are not detachably connected, specifically by welding. In this case, the cable cylinder 304 can be set to a longer length to meet drilling requirements.

[0078] The specific embodiment 5 of the TBM provided by this invention differs from embodiment 1 mainly in that: in embodiment 1, the parts are detachably connected via a threaded structure. In this embodiment, the parts can be conventional plug-in structures, as long as they can be quickly connected and disconnected.

[0079] The specific embodiment 6 of the TBM provided by this invention differs from embodiment 1 mainly in that: in embodiment 1, the fracturing device drive system 400 includes a rotary drive device 402. In this embodiment, the rotary drive device is not included. In specific use, for example, if the high-stress zone only exists in a certain direction of the rock mass, it is not necessary to adjust the circumferential range of the fracturing device.

[0080] Specific embodiment 1 of the rockburst prevention method of the present invention:

[0081] Example 1 of the rockburst prevention method is the same as the working steps described in Example 1 of the TBM above, and will not be described in detail here.

[0082] Specific embodiment 2 of the rockburst prevention method of the present invention:

[0083] The main difference between this embodiment and Embodiment 1 is that in Embodiment 1, the stress relief hole was drilled using a high-voltage electric pulse drill bit 301 that was coaxially integrated with the fracturing device. In this embodiment, the stress relief hole is drilled using an advanced drilling rig configured with a TBM.

[0084] Specific embodiment 3 of the rockburst prevention method of the present invention:

[0085] This embodiment is similar to Embodiment 3 of the TBM described above. During operation, excluding the fracture detection system, and with prior acquisition of rock geology data, the electro-fracture power and number of electro-fractures can be adjusted based on the prior laboratory data. The fracturing can be stopped when the target fracture is approached, and then an expanding fracturing agent is injected into the fracture through the fracturing tube. This can also ensure the fracturing range and achieve the rockburst stress release effect.

[0086] Specific embodiment 4 of the rockburst prevention method of the present invention:

[0087] The main difference between this embodiment and Embodiment 1 is that in this embodiment, the drilling depth of the stress relief hole is determined according to the location of the rockburst stratum, and is not limited to 2-3 times the diameter of the excavation section.

[0088] Specific embodiment 5 of the rockburst prevention method of the present invention:

[0089] The main difference between this embodiment and Embodiment 1 is that in this embodiment, the concentration of the expansion component of the cracking agent is constant, and the operation is stopped when the electro-cracking range reaches the range that the cracking agent can crack.

[0090] Finally, it should be noted that the above descriptions are merely 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 make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preventing rockbursts, characterized in that, The rockburst prevention method utilizes a rockburst generator comprising a high-voltage electric pulse drill bit, an electric rockburst generator, a rockburst tube, and a rigid cable drum, all coaxially connected in sequence. The electric rockburst generator includes a housing with a rockburst wave window containing a rockburst wave generating structure. The rockburst tube has a double-layer structure: the outer layer is a rockburst agent flow channel, and the inner layer contains a cable electrically connected to the electric rockburst generator. The outer periphery of the rockburst tube has a rockburst agent outlet communicating with the rockburst agent flow channel. The cable drum also has a double-layer structure: the outer layer is a rockburst agent channel communicating with the rockburst agent flow channel of the rockburst tube, and the inner layer is a cable channel containing a cable electrically connected to the cable in the inner layer of the rockburst tube. S1: The high-voltage electric pulse drill bit of the fracturing device drills a stress relief hole in the rock mass ahead. The electric fracturing generator, fracturing tube and cable drum of the fracturing device enter the stress relief hole simultaneously. S2: Power is supplied to the electro-fracture generator to generate a hydraulic-electric effect in the hole, forming a fracturing wave that causes fractures in the target rock mass until the fracture range approaches the target fracture range or the set range. S3: Through the outer layer of the fracturing tube and the cable cylinder and the fracturing agent outlet on the outer periphery of the fracturing tube, a self-expanding fracturing agent is introduced into the stress relief hole. The fracturing agent enters the crack and flows to the end of the crack. After the fracturing agent expands, it performs secondary fracturing on the end of the crack to achieve the stress relief requirement.

2. The rockburst prevention method according to claim 1, characterized in that, The depth of the stress relief hole is 2-3 times the diameter of the excavation section.

3. The rockburst prevention method according to claim 1, characterized in that, During electro-induced cracking, acoustic sensors are used to detect the extent of crack development.

4. The rockburst prevention method according to claim 1, characterized in that, The concentration of the expanding component in the crack initiator is determined based on the range of crack initiation required.

5. TBM, including rockburst prevention device, characterized in that, The rockburst prevention device includes a drilling device and a fracturing device. The fracturing device is connected to a propulsion drive device. The fracturing device includes a high-voltage electric pulse drill bit, an electric fracturing generator, a fracturing tube, and a rigid cable drum connected coaxially in sequence. The electric fracturing generator includes a shell with a fracturing wave window and a fracturing wave generating structure inside the fracturing wave window. The fracturing tube has a double-layer structure. The outer layer is a fracturing agent flow channel, and the inner layer contains a cable. The cable is electrically connected to the electric fracturing generator. The outer periphery of the fracturing tube has a fracturing agent outlet that communicates with the fracturing agent flow channel. The cable drum has a double-layer structure. The outer layer is a fracturing agent channel that communicates with the fracturing agent flow channel of the fracturing tube. The inner layer is a cable channel with a cable inside. The cable is electrically connected to the cable inside the fracturing tube.

6. The TBM according to claim 5, characterized in that, The rigid cable drum has detachable connection structures at both ends that cooperate with each other.

7. The TBM according to claim 5, characterized in that, The high-voltage electric pulse drill bit and the electro-fracturing generator are detachably connected, and the fracturing tube and the rigid cable drum are detachably connected.

8. The TBM according to claim 7, characterized in that, The detachable connection structures between the high-voltage electric pulse drill bit and the electro-fracturing generator, between the fracturing tube and the rigid cable drum, and at both ends of the rigid cable drum are all threaded connections.

9. The TBM according to claim 5, characterized in that, The fracturing device also includes a fracture detection system, which includes an acoustic sensor.

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