A device for predicting earthquakes in advance during tunnel TBM excavation

Abstract

The invention relates to the field of geological survey technology, and discloses a tunnel TBM excavation earthquake advance prediction excitation device, including an electric-driven hammer source excitation device and a source receiving device, two sets of electric-driven hammer source excitation devices are symmetrically installed near the face of the tunnel in the TBM excavator, multiple source receiving devices are installed at different positions of the inner wall of the tunnel, multiple skylight holes are opened on the shields on the left and right sides of the TBM excavator, the electric-driven hammer source excitation device includes a box, a lifting leg and a deflection seat, a mounting plate is fixed on the top of the lifting leg, the deflection seat is located above the mounting plate and is rotatably connected to the mounting plate, the box is arranged on the top of the deflection seat, a hammer rod is slidably arranged on the box, the hammer rod extends from the skylight hole to act on the tunnel wall to generate seismic signals, and the source receiving device includes a wireless seismic detector, which is used to receive seismic signals. A breakthrough in the advance prediction of seismic reflection in the shield-type TBM excavation tunnel is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of geological exploration, and in particular to a tunnel TBM excavation earthquake advance prediction excitation device. Background Art

[0002] With the construction of large-scale infrastructure in my country, some tunnels with large burial depth and long mileage are often encountered during construction. The existing geological problems are becoming more and more complex, and the number of geological units crossed is increasing. During the construction of underground tunnels, due to changes in geological conditions, sudden accidents often occur (such as landslides, water gushing, mud bursts, rock bursts, high gas and other geological disasters). Therefore, geological advance prediction during tunnel construction and excavation is particularly important. Through tunnel geological advance prediction, the adverse geological bodies in front of the tunnel face and their properties, locations, scales, occurrences and disaster possibilities can be predicted in time to prevent the occurrence of catastrophic accidents and provide a basis for the correct selection of excavation sections, support design parameters and optimization of construction plans.

[0003] At present, tunnel excavation is generally divided into drilling and blasting method and TBM method, and TBM method is further divided into open TBM excavation and shield TBM excavation. The most common tunnel excavation is the drilling and blasting method. The face and the wall are exposed, and the cave is relatively open and unobstructed. When conducting seismic reflection advance prediction, the excitation source can use conventional explosion excitation and hammer excitation, and the receiving detector can be directly coupled with the rock wall; therefore, it is relatively easy to carry out seismic reflection advance prediction on-site operations in drilling and blasting excavation and open TBM excavation tunnels. In shield TBM excavation, the tunnel face and the wall are all closed, the wall around the face is closed by the shield, and the excavated wall is closed by the prefabricated pipe segment. Conventional explosion excitation and hammer excitation cannot be directly implemented, and the receiving detector cannot be directly coupled with the rock wall; therefore, it is necessary to design an advance prediction excitation device specifically for shield TBM excavation. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a tunnel TBM excavation earthquake advance prediction excitation device, which achieves a breakthrough in carrying out earthquake reflection advance prediction in a shield TBM excavation tunnel.

[0005] The objective of the present invention is achieved through the following technical solutions: a tunnel TBM excavation earthquake advance prediction excitation device, including an electric-driven hammer source excitation device and a source receiving device, two groups of the electric-driven hammer source excitation devices are symmetrically installed near the face of the tunnel in the TBM tunneling machine, a plurality of the source receiving devices are installed at different positions on the inner wall of the tunnel, and a plurality of skylight holes are opened on the shields on the left and right sides of the TBM tunneling machine. The electric-driven hammer source excitation device includes a box body, a lifting leg and a deflection seat, a mounting plate is fixed on the top of the lifting leg, the deflection seat is located above the mounting plate and is rotatably connected to the mounting plate, the deflection axis of the deflection seat is parallel to the shield axis of the TBM tunneling machine, and the box body The top of the deflection seat is arranged, and an excitation mechanism is arranged in the box body, and the excitation mechanism includes a hammer rod, a hook tooth lever, a large spring and a small spring. The hammer rod is arranged horizontally and slidably penetrates the box body. A plurality of large springs are arranged around the hammer rod in the box body, and one end of the large spring is connected to the hammer rod, and the other end is connected to the inner wall of the box body. The hook tooth lever is arranged below the hammer rod and eccentrically hinged on the box body. The short arm end of the hook tooth lever is formed with a hook tooth, and a groove is provided at the bottom of the hammer rod. The small spring is arranged below the hook tooth lever, and one end of the small spring is connected to the long arm of the hook tooth lever, and the other end is connected to the inner bottom wall of the box body. The small spring is always in a stretched state;

[0006] The seismic source receiving device comprises a wireless seismic detector, and the wireless seismic detector is used to receive the seismic signal generated by the electric-driven hammering seismic source excitation device hammering the tunnel wall.

[0007] Furthermore, a locking hydraulic cylinder is horizontally installed in the box body, the telescopic shaft of the locking hydraulic cylinder is connected to a locking block, the locking hydraulic cylinder is perpendicular to the hook tooth lever, and a locking groove is provided on the side of the long arm section of the hook tooth lever close to the locking block, and when the hook tooth is adapted in the groove, the locking groove is located on the moving path of the locking block.

[0008] Furthermore, the top wall of the groove is a plane, the side wall of the groove away from the hook tooth lever is an abutment plane, the side wall of the groove close to the hook tooth lever is a wedge-shaped surface, the top of the hook tooth is an inclined contact surface, and the end of the hook tooth close to the groove is an inclined abutment surface. When the hook tooth is deflected upward into the groove, the inclined contact surface is deflected to a horizontal state and contacts with the plane, and the inclined abutment surface is deflected to be parallel to the abutment plane. When the inclined abutment surface contacts the abutment plane, the locking hydraulic cylinder drives the locking block to adapt to the locking groove.

[0009] Furthermore, a rack is fixed on the top of the hammer rod along its length direction, a large gear is rotatably arranged in the box body, the large gear meshes with the rack, a motor is installed in the box body, the output shaft of the motor is connected with a small gear, the small gear meshes with the large gear, a distance sensor is installed on the inner wall of the box body, the detection light path of the distance sensor is parallel to the rack, one end of the rack is located on the detection light path of the distance sensor, a vibration trigger switch is arranged on the hammer rod, and the vibration trigger switch is connected to the wireless seismic detector.

[0010] Furthermore, the large gear is rotatably connected to the box body through a driving shaft, the large gear is slidingly sleeved on the driving shaft through a spline, and the large gear is engaged with or separated from the rack by movement.

[0011] Furthermore, a driving disk is gap-fitted on the driving shaft, and the outer diameter of the driving disk is larger than the outer diameter of the large gear. A bearing circular groove is provided on the end face of the driving disk close to the large gear, and the bearing circular groove is coaxially arranged with the driving disk. A bearing is arranged in the bearing circular groove, and the outer wall of the bearing is connected to the driving disk. A hollow shaft is coaxially fixed to the end face of the large gear close to the driving disk, and the hollow shaft is connected to the inner ring of the bearing. A switching cylinder is installed in the housing, and the switching cylinder is parallel to the driving shaft. The telescopic shaft of the switching cylinder is connected to a gear shifting rod, and the gear shifting rod is located above the driving disk. Two limiting teeth are fixed on the bottom wall of the gear shifting rod at intervals, and the driving disk is limited between the two limiting teeth.

[0012] Furthermore, two bearing seats are fixed at intervals on the top of the mounting plate along the deflection axis of the deflection seat, a deflection shaft is arranged between the two bearing seats, the deflection shaft is rotatably connected to the bearing seats, the deflection seat is located between the two bearing seats and is fixedly mounted on the deflection shaft, a stepper motor is installed on one of the bearing seats, and the output shaft of the stepper motor is transmission-connected to the deflection shaft.

[0013] Furthermore, a buffer groove is provided on the top surface of the deflection seat along the moving direction of the hammer rod, a buffer spring is connected to the buffer groove, a buffer slider is fixed to the bottom of the box body, the buffer slider is slidably adapted in the buffer groove and connected to the buffer spring.

[0014] Furthermore, buffer support rods are provided on both sides of the rear of the box body, and the buffer support rods include rod one and rod two. The lower end of rod one is hinged to the bottom plate of the TBM tunneling machine, and the high end of rod one is provided with a sliding hole, and a long buffer spring is provided in the sliding hole. One end of rod two is clearance-fitted in the sliding hole, and the other end is hinged to the side wall of the box body. The two ends of the long buffer spring are respectively connected to rod one and rod two.

[0015] Furthermore, the seismic source receiving device also includes an iron casing and a glass fiber anchor rod. The iron casing passes through the prefabricated pipe segment and is connected to the surrounding rock, and is used to isolate the sand and gravel filled between the surrounding rock and the prefabricated pipe segment. The glass fiber anchor rod passes through the iron casing and is connected to the surrounding rock. The bottom of the glass fiber anchor rod is connected to the wireless seismic detector.

[0016] The beneficial effects of the present invention are:

[0017] A skylight hole is opened on the shield of the TBM for the hammer rod to extend out. The hammer rod moves close to the hook tooth lever, so that the hammer rod stretches the large spring to store force. When the hook tooth corresponds to the groove, the hook tooth lever is deflected under the force of the small spring so that the hook tooth fits into the groove, thereby locking the hammer rod. During implementation, the hook tooth lever drives the hook tooth to deflect away from the hammer rod, so that the hook tooth is disengaged from the groove. Under the reaction force of the large spring, the hammer rod is extended from the skylight hole and hammered on the tunnel wall, thereby generating a source signal. The seismic signal is received by a wireless seismic detector. The wireless seismic detector collects multi-layer reflection signals and performs three-dimensional inversion calculation on each layer of the medium in the tunnel, obtains a three-dimensional result map within a range of about 100m in front of the tunnel face, and analyzes the data for geological advance prediction, which solves the problem that the existing tunnel TBM boring machine cannot perform earthquake advance prediction and achieves a breakthrough in conducting earthquake reflection advance prediction in shield-type TBM tunneling tunnels. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the installation of an electric-driven hammer source excitation device in a tunnel TBM excavation earthquake advance prediction excitation device of the present invention;

[0019] Figure 2 It is a structural schematic diagram of an electric-driven hammer source excitation device in a tunnel TBM excavation earthquake advance prediction excitation device of the present invention;

[0020] Figure 3 A partial schematic diagram of an electric-driven hammer source excitation device in a tunnel TBM excavation earthquake advance prediction excitation device of the present invention Figure 1 ;

[0021] Figure 4 A partial schematic diagram of an electric-driven hammer source excitation device in a tunnel TBM excavation earthquake advance prediction excitation device of the present invention Figure 2 ;

[0022] Figure 5 It is a schematic diagram of the assembly of a large gear and a driving plate in a device for early prediction of earthquakes during tunnel TBM excavation according to the present invention;

[0023] Figure 6 It is a structural schematic diagram of a buffer support rod in a tunnel TBM excavation earthquake advance prediction excitation device of the present invention;

[0024] Figure 7 A schematic diagram of the installation of a source receiving device in a tunnel TBM excavation earthquake advance prediction excitation device according to the present invention;

[0025] Figure 8 A schematic diagram of the arrangement of the source point and the receiving point in a device for early prediction of earthquakes during tunnel TBM excavation according to the present invention;

[0026] Fig. 9 The three-dimensional imaging top view of the tunnel of the present invention;

[0027] Fig.10 It is a three-dimensional stereogram of the tunnel of the present invention;

[0028] In the figure, 1- skylight hole, 2- box body, 3- lifting leg, 4- deflection seat, 5- mounting plate, 6- hammer bar, 7- hook tooth lever, 8- large spring, 9- small spring, 10- hook tooth, 11- groove, 12- locking hydraulic cylinder, 13- locking block, 14- locking groove, 15- abutment plane, 16- wedge surface, 17- inclined contact surface, 18- inclined abutment surface, 19- rack, 20- large gear, 21- motor, 22- small gear, 23- distance sensor, 24- drive Moving shaft, 25-driving plate, 26-bearing circular groove, 27-bearing, 28-hollow shaft, 29-switching cylinder, 30-shifting gear rod, 31-limiting tooth, 32-bearing seat, 33-deflection shaft, 34-stepping motor, 35-buffer groove, 36-buffer spring, 37-buffer slider, 38-rod one, 39-rod two, 40-long buffer spring, 41-glass fiber anchor rod, 42-surrounding rock, 43-wireless seismic detector, 44-iron casing, 45-vibration trigger switch. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0030] like Figures 1 to 7As shown, a tunnel TBM excavation earthquake advance prediction excitation device includes an electric-driven hammer source excitation device and a source receiving device. Two sets of electric-driven hammer source excitation devices are symmetrically installed near the face of the tunnel in the TBM, and multiple source receiving devices are installed at different positions on the inner wall of the tunnel. Multiple skylight holes 1 are opened on the shields on the left and right sides of the TBM. The multiple skylight holes 1 are arranged at intervals along the circumference of the shield and are used to excite and generate seismic signals at different positions. The electric-driven hammer source excitation device includes a box 2, a lifting leg 3 and a deflection seat 4. A mounting plate 5 is fixed on the top of the lifting leg 3. The deflection seat 4 is located above the mounting plate 5 and is rotatably connected to the mounting plate 5. The deflection axis of the deflection seat 4 is parallel to the TBM. The shield axis of the M tunnel boring machine, the box body 2 is arranged on the top of the deflection seat 4, and an excitation mechanism is arranged in the box body 2, which includes a hammer rod 6, a hook tooth lever 7, a large spring 8 and a small spring 9. The hammer rod 6 is arranged horizontally and slidably penetrated on the box body 2. A plurality of large springs 8 are arranged around the hammer rod 6 in the box body 2, one end of the large spring 8 is connected to the hammer rod 6, and the other end is connected to the inner wall of the box body 2. The hook tooth lever 7 is arranged below the hammer rod 6 and eccentrically hinged on the box body 2. The short arm end of the hook tooth lever 7 is formed with a hook tooth 10, and a groove 11 is provided at the bottom of the hammer rod 6. The small spring 9 is arranged below the hook tooth lever 7, one end of the small spring 9 is connected to the long arm of the hook tooth lever 7, and the other end is connected to the inner bottom wall of the box body 2, and the small spring 9 is always in a stretched state;The source receiving device includes a wireless seismic detector 43, which is used to receive the seismic signal generated by the electric-driven hammer source excitation device hammering the tunnel wall. The lifting leg 3 can adjust the height of the hammer rod 6 so that the hammer rod 6 can extend from the skylight holes 1 at different heights to generate seismic signals. The lifting leg 3 is driven by a hydraulic cylinder or a pneumatic cylinder. Since the shape of the shield is circular and the excavated tunnel is also arc-shaped, in order to ensure that the hammer rod 6 is in good contact with the tunnel wall to generate a seismic source, the hammer rod 6 needs to generate seismic signals at different positions. For the positions of different skylight holes 1, the deflection seat 4 drives the box 2 to deflect so that the hammer rod 6 adapts to the curvature of the skylight hole 1 and deflects to ensure that the hammer rod 6 can act well on the tunnel wall after extending from the skylight hole 1 to generate seismic signals. The specific process of exciting the seismic signal is as follows: the hammer rod 6 moves close to the center of the shield so that the groove 11 on the hammer rod 6 moves close to the hook tooth lever 7 until the hook tooth 10 fits in the groove 11, and the hook tooth lever 7 stops moving. At this time, the large spring 8 is in a stretched state. When When it is necessary to generate a source signal, the hook lever 7 deflects, causing the hook 10 to deflect downward and disengage from the groove 11, thereby unlocking the motion state of the hammer rod 6. The hammer rod 6 moves away from the center of the shield under the reaction of the large spring 6, so that the hammer rod 6 extends from the skylight hole 1 and hits the rock wall of the tunnel to generate a seismic signal. When the seismic wave passes through the adjacent two layers of geological interface, due to the difference in wave impedance between the geological bodies, reflection and transmission phenomena occur. The reflected seismic wave is received by the wireless seismic detector 43, and the transmitted seismic wave enters the front geological body and continues to propagate until it encounters the geological interface again and reflects and transmits. In this way, the seismic wave can form a multi-layer reflection signal at each geological interface of the tunnel. The wireless seismic detector 43 collects the multi-layer reflection signal and performs a three-dimensional inversion calculation on each layer of the medium in the tunnel to obtain a three-dimensional geological image of the tunnel, thereby solving the problem that the existing tunnel TBM excavator cannot perform earthquake advance prediction, and achieving a breakthrough in conducting earthquake reflection advance prediction in the shield TBM excavation tunnel. ;

[0031] Furthermore, if Figures 2 to 4As shown, a locking hydraulic cylinder 12 is horizontally installed in the box body 2, and a locking block 13 is connected to the telescopic shaft of the locking hydraulic cylinder 12. The locking hydraulic cylinder 12 is perpendicular to the hook tooth lever 7. A locking groove 14 is provided on the side of the long arm section of the hook tooth lever 7 close to the locking block 13. When the hook tooth 10 is adapted in the groove 11, the locking groove 14 is located on the moving path of the locking block 13. In order to ensure that the hammer rod 6 can be smoothly extended from the skylight hole 1 after being released, the initial state of the hammer rod 6 installed in the shield is a power storage state, that is, the hook tooth 10 is adapted in the groove 11. 1 limits the movement of the hammer rod 6 so that the electric-driven hammer source excitation device does not interfere with the shield. At the same time, when released, it has enough length to extend from the skylight hole 1 to hammer on the tunnel rock wall. In order to ensure the locking stability of the hammer rod 6 and avoid the situation where the hammer rod 6 overcomes the force of the hook tooth lever 7 and is accidentally launched, after the hook tooth 10 is engaged in the groove 11, the locking hydraulic cylinder 12 extends to drive the locking block 13 to insert into the locking groove 14 of the hook tooth lever 7, and the hook tooth lever 7 is locked by hydraulic means, thereby locking the state of the hammer rod 1.

[0032] Furthermore, if Figure 3 and Figure 4As shown, the top wall of the groove 11 is a plane, the side wall of the groove 11 away from the hook tooth lever 7 is a contact plane 15, the side wall of the groove 11 close to the hook tooth lever 7 is a wedge-shaped surface 16, the top of the hook tooth 10 is an inclined contact surface 17, and the end of the hook tooth 10 close to the groove 11 is an inclined abutment surface 18. When the hook tooth 10 is deflected upward into the groove 11, the inclined contact surface 17 is deflected to a horizontal state and contacts with the plane, and the inclined abutment surface 18 is deflected to be parallel to the abutment plane 15. When the inclined abutment surface 18 contacts the abutment plane 15, the locking hydraulic cylinder 12 drives the locking block 13 to adapt to the locking groove 14. A rack 19 is fixed on the top of the hammer bar 6 along its own length direction. A large gear 20 is rotatably arranged in the box body 2, and the large gear 20 meshes with the rack 19. A motor 21 is installed, and the output shaft of the motor 21 is connected to a small gear 22, and the small gear 22 meshes with the large gear 20. A distance sensor 23 is installed on the inner wall of the box body 2, and the detection light path of the distance sensor 23 is parallel to the rack 19, and one end of the rack 19 is located on the detection light path of the distance sensor 23. A vibration trigger switch 45 is arranged on the hammer rod 6, and the vibration trigger switch 45 is connected to the wireless seismic detector 43. Since the electric-driven hammering seismic source excitation device is installed in the shield, it cannot be operated by personnel, and the electric-driven hammering seismic source excitation device is required to automatically start multiple hammering to generate a seismic source signal. Therefore, the motor 21 drives the small gear 22 to rotate, the small gear 22 drives the large gear 20 to rotate, and the large gear 20 drives the rack 19 to move, so that the rack 19 drives the hammer rod 6 to approach The hook-tooth lever 7 moves. It should be noted that when the hook-tooth lever 7 is in normal state (the hook tooth 10 contacts the bottom surface of the hammer rod 6), the inclined contact surface 17 and the inclined abutting surface 18 are both in an inclined state, and the inclined contact surface 17 is perpendicular to the inclined abutting surface 18, and the inclination angle is equal to the deflection angle of the hook-tooth lever 7 deflected to adapt to the groove 11. When the hammer rod 6 moves to the groove 11 corresponding to the hook tooth 10, under the action of the small spring 9, the hook-tooth lever 7 is deflected upward to adapt to the groove 11. At this time, the inclined contact surface 17 of the hook tooth 10 is deflected to a horizontal state to match the top wall of the groove 11, and then the hammer rod 6 continues to move until the inclined abutting surface 18 of the hook tooth 10 contacts the abutting plane 15. Since the inclined abutting surface 18 is in vertical contact with the abutting plane 15, Thereby limiting the freedom of the hammer rod 6 to continue to move in the direction close to the center of the shield, the hammer rod 6 stops moving at this time, and the feedback time of the distance sensor 23 is set within the overload range of the motor 21. When the distance sensor 23 detects that the distance of the rack 19 does not change within the set time, the feedback signal of the distance sensor 23 causes the locking hydraulic cylinder 12 to drive the locking block 13 to adapt to the locking groove 14, thereby locking the state of the hook tooth lever 7. At the same time, the motor 21 stops, thereby protecting the motor 21 and automatically switching the hammer rod 6 to the source excitation state. Then, the locking hydraulic cylinder 12 drives the locking block 13 to disengage from the locking groove 14. At this time, the hammer rod 6 moves away from the center of the shield under the reaction of the large spring 8, so that the hook tooth 10 contacts the wedge surface 16.Since the reaction force generated by the multiple large springs 8 is much greater than the force generated by the small springs 9, and the guiding effect of the wedge surface 16, the hammer rod 6 can press down the short arm of the hook tooth lever 7, so that the hook tooth lever 7 is disengaged from the groove 11, and then the hammer rod 6 extends from the skylight hole 1 to act on the tunnel wall to generate a source signal, change the source position, and according to the position of the skylight hole 1, through the deflection seat 4 corresponding to the angle of the deflection box 2, the extension line of the hammer rod 6 extending from the skylight hole 1 is roughly located at the center of the shield, ensuring that the hammer rod 6 acts well on the tunnel wall to generate a source signal, and the vibration trigger switch 45 is activated. The vibration trigger switch 45 activates the wireless seismic detector 43 to receive the source signal, and then repeats the above process to generate seismic signals at different source points.

[0033] Furthermore, if Figures 2 to 4As shown, the large gear 20 is rotatably connected to the housing 2 through the drive shaft 24, and the large gear 20 is slidably sleeved on the drive shaft 24 through a spline, and the large gear 20 is meshed or separated with the rack 19 by movement, and a drive plate 25 is gap-fitted on the drive shaft 24, and the outer diameter of the drive plate 25 is larger than the outer diameter of the large gear 20, and a bearing circular groove 26 is provided on the end face of the drive plate 25 close to the large gear 20, and the bearing circular groove 26 is coaxially arranged with the drive plate 25, and a bearing 27 is arranged in the bearing circular groove 26, and the outer wall of the bearing 27 is connected to the drive plate 25, and a hollow shaft 28 is coaxially fixed to the end face of the large gear 20 close to the drive plate 25, and the hollow shaft 28 is coaxially fixed to the end face of the large gear 20 close to the drive plate 25. The shaft 28 is connected to the inner ring of the bearing 28, and a switching cylinder 29 is installed in the box body 2. The switching cylinder 29 is parallel to the drive shaft 24. The telescopic shaft of the switching cylinder 29 is connected to a gear lever 30. The gear lever 20 is located above the drive disk 25. Two limiting teeth 31 are fixed at intervals on the bottom wall of the gear lever 20. The drive disk 25 is limited between the two limiting teeth 31. In order to protect the motor 21 and ensure that the seismic signal generated by the hammer rod 6 does not interfere with the output shaft of the motor 21, the self-locking ability of the motor 21 also does not affect the movement of the hammer rod 6, ensuring that the hammer rod 6 smoothly generates seismic signals. For this reason, when the hammer rod 6 is in the power storage state, Before the locking block 13 is out of the locking groove 14, the transmission between the motor 21 and the hammer rod 6 is first cut off to ensure that when the hammer rod 6 is released, the hammer rod 6 and the motor 21 will not affect each other. Specifically, the switching cylinder 29 drives the driving disk 25 to move away from the hammer rod 6. Since the large gear 20 is connected to the bearing 27 through the hollow shaft 28, the driving disk 25 will drive the large gear 20 to move away from the rack 19, so that the large gear 20 is separated from the rack 19, and the motor 21 meshes with the large gear 20 through the small gear 22, thereby indirectly cutting off the transmission between the motor 6 and the hammer rod 6, ensuring that the hammer rod 6 will not affect each other when the seismic signal is released. It will interact with the motor 21. At the same time, the setting of the bearing 27 enables the large gear 20 and the driving disk 25 to rotate relative to each other, and does not affect the transmission of the large gear 20 and the small gear 22. When the hammer rod 6 generates a seismic signal, the switching cylinder 29 pushes the driving disk 25 to move close to the hammer rod 6, so that the driving disk 25 drives the large gear 20 to move close to the rack 19, so that the large gear 20 is reset and moves with the rack 19 again, so that the motor 21 drives and connects to the hammer rod 6. The motor 21 starts, so that the hammer rod 6 moves close to the center of the shield, and the hammer rod 6 returns to the shield and is in a power storage state again, waiting for the next start.

[0034] Furthermore, if Figure 2As shown, two bearing seats 32 are fixed at intervals along the deflection axis of the deflection seat 4 on the top of the mounting plate 5, a deflection shaft 33 is arranged between the two bearing seats 32, the deflection shaft 33 is rotatably connected to the bearing seats 32, the deflection seat 4 is located between the two bearing seats 32, and is fixedly mounted on the deflection shaft 33, a stepper motor 34 is installed on one of the bearing seats 32, the output shaft of the stepper motor 34 is connected to the deflection shaft 33, the stepper motor 34 can control the rotation angle, according to the layout position of the skylight hole 1, the lifting leg 3 drives the box body 2 to move to the specified position in the height direction, and then the stepper motor 34 drives the deflection shaft 33 to rotate, so that the deflection shaft 33 drives the deflection seat 4 to deflect, thereby causing the box body 2 to deflect to the specified position, so that the hammer rod 6 can extend from the corresponding skylight hole 1, and the extension line of the hammer rod 6 passes through the center of the shield.

[0035] Furthermore, if Figure 2 and Figure 6 As shown. The top surface of the deflection seat 4 is provided with a buffer groove 35 along the moving direction of the hammer rod 6, and a buffer spring 36 is connected in the buffer groove 35. A buffer slider 37 is fixed to the bottom of the box body 2, and the buffer slider 37 is slidably adapted in the buffer groove 35 and connected to the buffer spring 36. Buffer support rods are arranged on both sides of the tail of the box body 2, and the buffer support rods include a rod 1 38 and a rod 2 39. The lower end of the rod 1 38 is hinged to the bottom plate of the TBM tunneling machine, and the high end of the rod 1 38 is provided with a sliding hole 39, and a long buffer spring 40 is arranged in the sliding hole 39. One end of the rod 2 39 is clearance-fitted in the sliding hole 39, and the other end is hinged to the side wall of the box body 2. The two ends of the long buffer spring 40 are respectively connected to the rod 1 38 and the rod 2 39. After the hammer rod 6 acts on the tunnel wall, the generated In order to reduce the vibration of the parts in the box body 2, a double buffer structure is set. The vibration generated by the hammer rod 6 will directly act on the box body 2, and the box body 2 will transmit the vibration to the buffer spring 36 and the buffer support rod, and the vibration is buffered by the buffer spring 36. At this time, the box body 2 will move, so that the vibration acts on the buffer support rod. Since the rod 1 38 and the rod 2 39 are in a clearance sliding fit, they can adapt to the movement of the box body 2 to deflect the buffer support rod, and make the rod 1 38 squeeze the buffer spring 40, further buffering the vibration of the box body 2, so as to quickly buffer the vibration of the box body 2 by double buffering, play a role in protecting the parts in the box body 2, and extend the service life of the electric-driven hammer vibration source excitation device.

[0036] Furthermore, if Figure 7As shown, the seismic source receiving device also includes an iron casing 44 and a glass fiber anchor 41. The iron casing 44 passes through the prefabricated pipe segment and connects to the surrounding rock 42, which is used to isolate the gravel filled between the surrounding rock 42 and the prefabricated pipe segment. The glass fiber anchor 41 passes through the iron casing 44 and connects to the surrounding rock 42. The bottom of the glass fiber anchor 41 is connected to a wireless seismic detector 43. After the TBM is excavated, the cave wall is supported by the prefabricated pipe segment, and gravel is filled between the surrounding rock 42 and the prefabricated pipe segment. The seismic source receiving device cannot be directly coupled to the surrounding rock 42. For this reason, the prefabricated pipe segment has a hole position for the iron casing 44 to pass through at the receiving point position. The hole position is weakened and the prefabricated pipe segment is used to connect the surrounding rock 42. Reserve a space and use an impact drill to pierce the reserved space of the pipe segment. Since the reserved space has been weakened, it can be easily pierced. Then insert the iron casing 44 from the reserved space to the surrounding rock 42 to prevent the filled gravel from flowing out of the reserved space. Clean the gravel in the iron casing 44, drill a small hole in the surrounding rock 42 with an impact drill, apply quick-setting cement on the tip of the fiberglass anchor rod 41, and insert it into the small hole in the surrounding rock 42 to fully fix the fiberglass anchor rod 41 and the surrounding rock 42. Then fix the wireless seismic detector 43 on the rod head of the fiberglass anchor rod 41 with quick-setting cement, repeat the above process, and install the source receiving device at each receiving point.

[0037] In summary, if Figure 8 As shown, a method for advance prediction using a tunnel TBM excavation earthquake advance prediction excitation device includes the following steps:

[0038] S1. An electric-driven hammer shock source excitation device is installed on the left and right sides of the TBM tunnel boring machine near the tunnel face, and a plurality of skylight holes 1 are opened on the shields on the left and right sides of the TBM tunnel boring machine. The skylight holes 1 are used for the hammer rod 6 to extend and strike the tunnel wall to excite seismic waves;

[0039] S2, the impact position of hammer rod 1 is the source point, and the receiving device is arranged 20m behind the excitation point. At least four groups of receiving sections are arranged, and the distance between two adjacent groups of receiving sections is 5m. Two or three source receiving devices are arranged on the receiving section, and the signal receiving position of the source receiving device is the receiving point;

[0040] S3, measure the relative coordinates of all earthquake source points and all receiving points; measure the relative coordinates of earthquake source points and receiving points with the help of laser rangefinder, tape measure and other tools;

[0041] S4, the electric hammer source excitation device is activated to excite the seismic signal at the source point, and the source receiving device at the receiving point receives the seismic reflection wave signal;

[0042] S5. The electric-driven hammer source excitation device is powered off, and the source receiving devices and other auxiliary devices at each receiving point are recovered;

[0043] S6. Through data processing and calculation of reflection coefficient, a three-dimensional result map within a range of about 100m in front of the tunnel face is obtained, and the data is analyzed for geological advance forecasting.

[0044] In step S2, four groups of receiving sections are arranged, and two adjacent groups of receiving sections are respectively provided with two seismic source receiving devices and three seismic source receiving devices, the two seismic source receiving devices are respectively arranged on the left and right side walls of the prefabricated pipe segment, and the three seismic source receiving devices are respectively arranged on the top arch and the left and right side walls; in step S2, two skylight holes 1 are opened on each of the left and right sides to form four seismic source points.

[0045] The specific measurement method of step S3 is as follows:

[0046] Three seismic source receiving devices are set up at the last group of receiving sections away from the tunnel face. The origin of the relative coordinate system is set at the center of the arc formed by the three receiving points of the receiving section. The direction from the origin to the tunnel face is the positive direction of the X axis, the direction from the origin to the right side of the tunnel face is the positive direction of the Y axis, and the direction from the origin upward is the positive direction of the Z axis. After the prefabricated segments of the TBM are installed, it is a circular tunnel model. Dongjing is a fixed value, recorded as Y0;

[0047] Use measuring tools (laser rangefinder, tape measure, etc.) to measure the relative coordinates X of each source point and receiving point, or calculate the difference in the number of rings of the prefabricated segments where the source point and the receiving point are located relative to the coordinate origin. Since the size of the prefabricated segment is known, the relative coordinates X of the source point and the receiving point can be calculated based on the length of the prefabricated segment;

[0048] Y coordinate: For the receiving point, since the source receiving device is installed on the surrounding rock 42 of the prefabricated segment, the distance from the inner surface of the prefabricated segment to the surface of the surrounding rock 42 is first measured, which is recorded as Y1. The horizontal distance of the inner surface of the prefabricated segment where the receiving point of the wireless seismic detector 43 in the receiving device is located relative to the coordinate origin is recorded as Y2, Y=Y1+Y2. The source point is measured in the same way, that is, the horizontal distance of the hammering position of the hammer rod 6 relative to the coordinate origin;

[0049] The Z coordinate is calculated based on triangular geometry. The Z coordinates of each source point and receiving point are calculated in turn.

[0050] Through data processing, the reflection coefficient is calculated, and a three-dimensional result map within 100m of the tunnel face is obtained, and the data is analyzed for geological advance prediction. The specific step S7 is as follows: when the seismic wave passes through the two adjacent geological interfaces, the reflection and transmission phenomena occur due to the difference in wave impedance between the geological bodies. The reflected seismic wave is received by the wireless seismic detector 4, and the transmitted seismic wave enters the geological body in front and continues to propagate until it encounters the geological interface again and reflects and transmits. In this way, the seismic wave can form a multi-layer reflection signal at each geological interface of the tunnel. The wireless seismic detector 4 collects the multi-layer reflection signal and performs a three-dimensional inversion calculation on each layer of the medium in the tunnel to obtain a three-dimensional geological image of the tunnel. The reflection coefficient and the transmission coefficient calculation formula are:

[0051]

[0052] Where: R is the reflection coefficient, T is the transmission coefficient, ρ1 and ρ2 are the densities of the rock medium before and after the geological interface, V1 and V2 are the propagation velocities of seismic waves in the rock medium before and after the geological interface.

[0053] It can be seen from the formula that the strength of reflection and transmission of seismic waves is directly related to the rock and soil properties of the geological bodies before and after the interface, that is, when the seismic wave enters the hard rock layer from the soft rock layer, the reflection coefficient is positive, otherwise, the reflection coefficient is negative; when the wave impedance between the rock bodies at the interface is very different, the reflection is strong and the transmission is weak. On the contrary, the reflection is weak and the transmission is strong. The study of these laws is helpful to comprehensively judge the lithology characteristics in the tunnel detection area.

[0054] like Fig. 9 and Fig.10 As shown, according to the implementation case of the above-mentioned advance forecasting device and forecasting method:

[0055] The total length of the Q tunnel is about 5540m, and the maximum burial depth of the tunnel is about 650m. The inner diameter of the tunnel is 8.1m, and the excavation diameter is 9.13m. The first 150m of the tunnel (pile number K0~K0+200) is excavated by manual drilling and blasting, and the subsequent tunnel section is excavated by shield TBM construction. Due to the closed structure formed by the TBM shield and prefabricated segments, the rock mass is isolated, not only is it difficult to arrange and implement the excitation and receiving profiles, but the locations of the source excitation points and receiving points are easily blocked by various equipment, making it difficult to measure the geodetic coordinates of each point with measurement equipment.

[0056] The Q tunnel used the device and method proposed in the present invention to carry out advance prediction in the TBM excavation section. In this tunnel, the system problem of being unable to carry out excitation, reception and coordinate measurement due to the full closure of the tunnel body in the shield TBM excavation tunnel was overcome, and a breakthrough in carrying out advance prediction of seismic reflection in the shield TBM excavation tunnel was achieved.

[0057] Table 1 is a comparison table of the advance prediction and actual excavation of the Q tunnel. It can be seen that the geological conditions of the section predicted in advance are basically consistent with the geological conditions revealed by the actual excavation. The prediction error within 100m is within 5m. It is sensitive to the fracture structure and has a high prediction accuracy. Therefore, the device and method proposed in the present invention are feasible for conducting seismic reflection advance prediction in shield TBM tunneling tunnels, and the effect is good.

[0058] Table 1 Comparison between advance prediction and actual excavation of Q tunnel

[0059]

[0060]

Claims

1. A device for predicting earthquakes in advance during tunnel TBM excavation, characterized in that: The invention comprises an electric-driven hammer source excitation device and a source receiving device. Two groups of the electric-driven hammer source excitation devices are symmetrically installed near the face of the tunnel in a TBM tunnel boring machine. A plurality of the source receiving devices are installed at different positions on the inner wall of the tunnel. A plurality of skylight holes (1) are provided on the shields on the left and right sides of the TBM tunnel boring machine. The electric-driven hammer source excitation device comprises a box (2), lifting legs (3) and a deflection seat (4). A mounting plate (5) is fixed on the top of the lifting legs (3). The deflection seat (4) is located above the mounting plate (5) and is rotatably connected to the mounting plate (5). The deflection axis of the deflection seat (4) is parallel to the shield axis of the TBM tunnel boring machine. The box (2) is arranged on the top of the deflection seat (4). An excitation mechanism is arranged in the box (2). The excitation mechanism comprises a hammer rod (6), A hook-tooth lever (7), a large spring (8) and a small spring (9), wherein the hammer rod (6) is arranged horizontally and slidably penetrates the box body (2), a plurality of large springs (8) are arranged around the hammer rod (6) in the box body (2), one end of the large spring (8) is connected to the hammer rod (6), and the other end is connected to the inner wall of the box body (2), the hook-tooth lever (7) is arranged below the hammer rod (6) and eccentrically hinged on the box body (2), a hook tooth (10) is formed at the short arm end of the hook-tooth lever (7), a groove (11) is provided at the bottom of the hammer rod (6), the small spring (9) is arranged below the hook-tooth lever (7), one end of the small spring (9) is connected to the long arm of the hook-tooth lever (7), and the other end is connected to the inner bottom wall of the box body (2), and the small spring (9) is always in a stretched state; The seismic source receiving device comprises a wireless seismic detector (43), and the wireless seismic detector (43) is used to receive seismic signals generated by the electric-driven hammering seismic source excitation device hammering the tunnel wall.

2. The device for early prediction of earthquake during tunnel TBM excavation according to claim 1 is characterized in that: A locking hydraulic cylinder (12) is horizontally installed in the box body (2); a telescopic shaft of the locking hydraulic cylinder (12) is connected to a locking block (13); the locking hydraulic cylinder (12) is perpendicular to the hook tooth lever (7); a locking groove (14) is provided on a side of a long arm section of the hook tooth lever (7) close to the locking block (13); when the hook tooth (10) is fitted into the groove (11), the locking groove (14) is located on a moving path of the locking block (13).

3. The device for early prediction of earthquake during tunnel TBM excavation according to claim 2 is characterized in that: The top wall of the groove (11) is a plane, the side wall of the groove (11) away from the hook tooth lever (7) is an abutment plane (15), the side wall of the groove (11) close to the hook tooth lever (7) is a wedge-shaped surface (16), the top of the hook tooth (10) is an inclined contact surface (17), and one end of the hook tooth (10) close to the groove (11) is an inclined abutment surface (18); when the hook tooth (10) deflects upward into the groove (11), the inclined contact surface (17) deflects to a horizontal state and contacts with the top wall plane of the groove (11), and the inclined abutment surface (18) deflects to be parallel to the abutment plane (15); when the inclined abutment surface (18) contacts the abutment plane (15), the locking hydraulic cylinder (12) drives the locking block (13) to fit into the locking groove (14).

4. The device for early prediction of earthquakes during tunnel TBM excavation according to claim 3 is characterized in that: A rack (19) is fixed to the top of the hammer rod (6) along its length direction; a large gear (20) is rotatably arranged in the box (2), and the large gear (20) meshes with the rack (19); a motor (21) is installed in the box (2); an output shaft of the motor (21) is connected to a small gear (22), and the small gear (22) meshes with the large gear (20); a distance sensor (23) is installed on the inner wall of the box (2); a detection optical path of the distance sensor (23) is parallel to the rack (19), and one end of the rack (19) is located on the detection optical path of the distance sensor (23); a vibration trigger switch (45) is arranged on the hammer rod (6), and the vibration trigger switch (45) is connected to the wireless seismic detector (43).

5. The device for early prediction of earthquakes during tunnel TBM excavation according to claim 4 is characterized in that: The large gear (20) is rotationally connected to the housing (2) via a drive shaft (24); the large gear (20) is slidingly sleeved on the drive shaft (24) via a spline; the large gear (20) engages with or disengages from the rack (19) by movement.

6. The device for early prediction of earthquakes during tunnel TBM excavation according to claim 5, characterized in that: A drive plate (25) is gap-fitted on the drive shaft (24); the outer diameter of the drive plate (25) is larger than the outer diameter of the large gear (20); a bearing circular groove (26) is provided on the end surface of the drive plate (25) close to the large gear (20); the bearing circular groove (26) is coaxially arranged with the drive plate (25); a bearing (27) is arranged in the bearing circular groove (26); the outer wall of the bearing (27) is connected to the drive plate (25); and the end surface of the large gear (20) close to the drive plate (25) is coaxially fixed to the drive plate (25). A hollow shaft (28) is fixed therein, the hollow shaft (28) being connected to the inner ring of the bearing (27), a switching cylinder (29) being installed in the housing (2), the switching cylinder (29) being parallel to the driving shaft (24), the telescopic shaft of the switching cylinder (29) being connected to a gear shifting rod (30), the gear shifting rod (30) being located above the driving disk (25), two limiting teeth (31) being fixed at intervals on the bottom wall of the gear shifting rod (30), and the driving disk (25) being limited between the two limiting teeth (31).

7. The device for early prediction of earthquakes during tunnel TBM excavation according to claim 1, characterized in that: Two bearing seats (32) are fixed at intervals on the top of the mounting plate (5) along the deflection axis of the deflection seat (4); a deflection shaft (33) is arranged between the two bearing seats (32); the deflection shaft (33) is rotatably connected to the bearing seats (32); the deflection seat (4) is located between the two bearing seats (32) and is fixedly mounted on the deflection shaft (33); a stepper motor (34) is installed on one of the bearing seats (32); and the output shaft of the stepper motor (34) is transmission-connected to the deflection shaft (33).

8. The device for early prediction of earthquakes during tunnel TBM excavation according to claim 1, characterized in that: A buffer groove (35) is formed on the top surface of the deflection seat (4) along the moving direction of the hammer rod (6), and a buffer spring (36) is connected to the buffer groove (35). A buffer slide block (37) is fixed to the bottom of the box body (2), and the buffer slide block (37) is slidably adapted in the buffer groove (35) and connected to the buffer spring (36).

9. The device for early prediction of earthquakes during tunnel TBM excavation according to claim 8, characterized in that: Buffer support rods are arranged on both sides of the rear of the box body (2), and the buffer support rods include a rod 1 (38) and a rod 2 (39). The lower end of the rod 1 (38) is hinged on the bottom plate of the TBM tunneling machine, and the upper end of the rod 1 (38) is provided with a sliding hole, in which a long buffer spring (40) is arranged. One end of the rod 2 (39) is loosely fitted in the sliding hole, and the other end is hinged on the side wall of the box body (2). The two ends of the long buffer spring (40) are respectively connected to the rod 1 (38) and the rod 2 (39).

10. The device for early prediction of earthquakes during tunnel TBM excavation according to claim 1, characterized in that: The seismic source receiving device further comprises an iron casing (44) and a glass fiber anchor rod (41); the iron casing (44) passes through the prefabricated pipe segment and is connected to the surrounding rock (42) so as to isolate the sand and gravel filled between the surrounding rock (42) and the prefabricated pipe segment; the glass fiber anchor rod (41) passes through the iron casing (44) and is connected to the surrounding rock (42); and the bottom of the glass fiber anchor rod (41) is connected to the wireless seismic detector (43).

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