CN106873040A - The airborne resistivity forward probe Real-time Collection electrode system of rock tunnel(ling) machine and method - Google Patents

Abstract

The invention discloses an electrode system and method for advance detection and real-time acquisition of an airborne resistivity method on a tunnel boring machine, which includes a variable direction electrode mechanism, an elastic expansion device and a variable resistance positioning mechanism. Direction transmission part, the contact electrode part freely rotates around its central axis through the direction change transmission part, and converts the sliding friction in contact with the rock surface into rolling friction; the elastic expansion device ensures the retraction and ejection of the electrode; the variable resistance positioning mechanism includes a sliding The rheostat is positioned with the polar coordinate system as the coordinate axis, and the center of the cutter head as the center of the polar coordinate system. By detecting the change of the resistance value of the sliding rheostat, the different positions of the cutter head are determined to calculate the position of the tracking electrode. The invention can effectively realize the detection during the excavation process of the cutter head.

Description

Tunnel boring machine airborne resistivity advance detection real-time acquisition electrode system and method

technical field

The invention relates to an electrode system and method for advanced detection and real-time acquisition of an airborne resistivity method of a tunnel boring machine.

Background technique

The rapid development of my country's economy and society in the 21st century has promoted the rapid development of science and technology. In recent years, tunnel engineering construction has achieved fruitful results. Among them, tunnel boring machine, as a kind of tunnel construction and excavation equipment with many advantages such as fast excavation speed, high construction safety, small surface disturbance, low labor cost and high degree of mechanical automation, is widely used in the construction of major tunnels at home and abroad. Greatly improved the mechanization and automation level of tunnel construction.

However, due to the uncertainty of the geological body ahead of the excavation, during the forward excavation process of the tunnel boring machine, water inrush, mud inrush, stuck In the event of accidents such as airplanes and landslides, economic losses and casualties are unavoidable. In view of the underground "black box" problem, it is necessary to use advanced geological prediction methods to detect unfavorable geological bodies in advance. The advanced geological prediction technology of three-dimensional resistivity method for tunnel boring machine is a kind of advanced geological prediction method suitable for tunnel boring machine. The specific implementation method of this advanced forecast method is: install measuring electrodes on the surface of the cutter head, install shielding electrodes around, and connect the electrodes to the main control room through cables, and the electrodes are in contact with the front and surrounding rocks, and the focus scan mode is used to collect data sequentially. Data; establish an excitation electric field in front of the face, and the water body in the geological body will generate a secondary polarization electric field. After the excitation electric field is turned off, the position and water volume of the water body can be judged by measuring the decay time of the polarization electric field and the apparent resistivity , so as to realize an advanced geological prediction method adapted to the tunneling method with the tunnel boring machine as the core. At present, this method is only applicable to the tunnel boring machine in the shutdown state. It can use the routine maintenance time of the tunnel boring machine for detection, making full use of the spare time and improving the tunneling efficiency.

However, there are still some problems with this detection method. Detection is performed when the tunnel boring machine is shut down for maintenance. The detected distance is limited. When the tunnel boring machine is driven to this length, it must be stopped, because the detected part has passed, and there is an unknown geological body ahead, so it must wait. Excavation can only be restarted after re-detection, which will lead to a reduction in excavation efficiency. If the real-time data collection during tunnel boring machine excavation can be realized, the above problems can be avoided, and the detection efficiency and detection coverage mileage can be improved. However, in order to realize the real-time detection process during the excavation process, the detection electrodes carried by the cutter head of the tunnel boring machine face many difficulties.

On the one hand, because the rock on the working face may be broken and rough, the cutter head will directly contact with such rock face during the rotating excavation process. At the same time, the existing electrode device is a fixed electrode, which does not have the ability to roll. When the cutter head rotates, the electrode will produce sliding friction with the rock surface, resulting in wear and damage of the electrode head, making it difficult to use.

On the other hand, when the electrode is stretched out, it often encounters uneven rock faces. Since the current electrodes are still controlled by hydraulic cylinders, the overall design is rigid and cannot be stretched at will. It is difficult to rebound at any time when facing such rock faces. This situation will seriously affect the exploration effect. For example, if the electrode passes through a protrusion on the rock face, the protruding rock will damage the electrode, and may even break the electrode; if it passes through a depression on the rock face, the electrode will not be in good contact with the rock face, which will affect the detection effect.

Furthermore, the three-dimensional resistivity inversion method requires that in the process of real-time electrode acquisition, the position of the acquisition electrode corresponding to each set of observation data needs to be corresponded to know the specific position of the data collected by monitoring the rock surface and the geological body data information at this position. , to achieve effective and usable monitoring and forecasting. Since the cutter head is always in a rotating state during the excavation process, it is difficult to locate the electrode position in real time when the electrode is working, which will lead to the inaccurate positioning of the position coordinates of the collected data, so that it is impossible to intuitively and accurately understand the geological conditions of the tunnel face ahead.

Contents of the invention

In order to solve the above problems, the present invention proposes a tunnel boring machine airborne resistivity method for advance detection and real-time acquisition electrode system and method. The adaptability of the geological rock surface improves the detection accuracy, and it can position the electrode in real time to ensure the accuracy of the measurement data and provide an important basis for data processing. This technology uses variable direction electrode equipment to solve the problem that the electrode is prone to excessive wear due to the large roughness of the rock on the face; through the elastic expansion device, it solves the problem of poor adaptability of the electrode to the uneven rock surface; The real-time positioning problem can effectively realize the detection during the excavation process of the cutter head

In order to achieve the above object, the present invention adopts the following technical solutions:

A tunnel boring machine airborne resistivity method advance detection real-time acquisition electrode system, including a variable direction electrode mechanism, an elastic expansion device and a variable resistance positioning mechanism, wherein:

The variable-direction electrode mechanism includes a contact electrode part and a direction-changing transmission part. The contact electrode part contacts the electrode and directly contacts the rock surface during the excavation process to excite an electric field. The shaft rotates freely, converting the sliding friction in contact with the rock surface into rolling friction;

The elastic telescopic device includes a power contraction part and an elastic propulsion part. The elastic propulsion part is assembled behind the electrode and is closely connected with the inside of the cutter head. The power contraction part is arranged on the edge of the electrode to apply force to the indentation of the electrode to overcome the elastic propulsion the spring force exerted by the part;

The rheostat positioning mechanism includes a sliding rheostat, which is positioned with the polar coordinate system as the coordinate axis, and the center of the polar coordinate system is taken as the center of the cutter head, and the different positions of the cutter head are determined by detecting the change of the resistance value of the sliding rheostat. Estimate the location of the tracking electrodes.

The direction-changing transmission member includes a wheel frame, a wheel shaft rotating bearing and a wheel-type end. One end of the wheel frame is arranged at the tail end of the contact electrode, and the other end is connected to the central axis of the wheel-type end through the wheel shaft rotating bearing, so that The electrode rod rotates freely around the central axis of the wheeled head.

The direction-changing transmission member enables the contact electrode device to freely rotate under control, so as to adapt to the rotation of the cutterhead.

The contact electrode part transmits the detection information in the form of current to the electrode rod through the wheel frame of the direction changing transmission part and the rotating bearing of the wheel shaft.

Preferably, the material of the contact electrode part is selected from tungsten-copper alloy, which has good electrical conductivity and certain wear resistance, and also has high high-temperature strength and certain plasticity, and the high-temperature strength can avoid friction. Heat can cause damage to the mechanism, and plasticity can ensure good contact between the electrode and the rock surface. The contact electrode part changes the existing rubber electrode contact end to a wheel structure, replacing sliding friction with rolling friction, allowing the wheel end to rotate 360 degrees horizontally in the rock surface plane, which greatly reduces the contact between the electrode and the rock surface. friction.

Further, the variable direction electrode mechanism also includes a fixed protection device, the fixed protection device includes a bearing plate and an elastic gasket, the bearing plate is arranged at the connection between the end of the electrode rod and the direction changing transmission member, and the elastic The washer is arranged on the elastic washer. The bearing plate of the fixed protection device plays the role of increasing the load capacity, and the elastic gasket increases the shock resistance of the variable direction electrode mechanism during the excavation process, and has the effect of strengthening and protecting the electrode.

Preferably, the power contraction part is a hydraulic contraction device, which includes two hydraulic cylinders, symmetrically distributed on both sides of the electrode rod, and connected to the electrode rod to provide force for the retraction of the electrode.

Preferably, the elastic propulsion part is a spring, and the spring is fixed behind the electrode rod, connected to the tail of the electrode rod, and the other end is tightly connected to the cutter head.

Of course, under the enlightenment of the working principle of the present invention, those skilled in the art can change the power contraction parts, such as changing them into power sources or other forms, or replace the elastic propulsion parts with other elastic parts or devices that can realize stretching. No creative work is required, and should belong to the protection scope of the present invention.

The variable resistance positioning mechanism includes a ring-shaped rheostat device, a control circuit device, and a signal processing and transmission device. An ammeter is used to monitor the current in the circuit to monitor the resistance value of the ring-shaped rheostat device, so as to achieve real-time monitoring of the position of the electrode and the rheostat positioning. The mechanism is installed on the inner side of the cutterhead back panel.

Further, the annular rheostat device is composed of a ring-shaped sliding rheostat, which surrounds the center point of the cutter head and is installed inside the back panel of the cutter head. The electrode rod is rigidly connected to the ring-shaped rheostat device through scribing to form a sliding rheostat.

The ring rheostat device may not be a whole ring, so as to avoid the situation that the resistance value may not be unique in the measurement, and provide the material basis for the detection of the whole set of mechanisms.

Further, the control circuit device includes a power supply mechanism, a current detection device and wires. The wires are divided into two types: movable wires and fixed wires. The wires connecting the electrodes and the ring rheostat device are movable wires. While rotating, the wires connecting the ring-shaped variable resistance device, the power supply mechanism and the current detection device belong to the fixed wires.

A ring wire identical to the path is arranged on the path of the rotating movement of the electrode to form a closed loop.

The signal processing and transmission device includes a transmission cable and a signal processor, the transmission cable connects the current detection device and the signal processor, and the signal processor converts the returned current information into resistance information.

Preferably, the signal processor is placed in the main control room.

Based on the working method of the above device, the variable direction electrode mechanism rotates adaptively with the movement of the cutter head. When the mechanism is not working, it is retracted in the cutter head, and when it is working, it pops up. The propulsion part rebounds, and the electrode pops out to contact the rock face. If the cutterhead encounters a concave-convex interface when it rotates, at the concave interface, the electrode is pressed against the rock face by the driving force exerted by the elastic propulsion part that is still in a compressed state. At the convex interface, the extruded part of the electrode is retracted, and the elastic propulsion part is recompressed to ensure that the contact electrode is always in good contact with the rock surface. The variable resistance positioning mechanism is used to monitor the electrode position in real time, and the polar coordinate system is used for positioning. The center of the cutter head is the center of the polar coordinate system, and the magnitude of the current in the circuit is detected to monitor the change of the resistance value and calculate the position of the tracking electrode.

Compared with prior art, the beneficial effect of the present invention is:

1. The electrode system and technology provided by the present invention can be used in the excavation process to realize real-time detection of the excavation process, avoiding the problem of affecting the normal construction process of the tunnel boring machine due to shutdown detection, and greatly improving the efficiency of excavation and detection. , collected in real time during the excavation process, can enable the detection to cover the entire mileage of the tunnel excavation, and avoid false alarms of unfavorable geological bodies.

2. The present invention proposes a variable direction electrode mechanism device. Through the combination of contact electrode device, direction change transmission device and fixed protection device, the real-time contact between the electrode and the face of the tunnel is realized during the excavation process, which solves the problem of the cutter head. During the rotation, the electrode head and the rock surface produce a lot of friction, which leads to serious wear of the electrode head.

3. The invention adds the proposed elastic telescopic device, adopts a new electrode stretching and retracting mechanism, uses the spring to provide the ejection force, and the hydraulic cylinder to provide the retraction force, so that the spring is always in a state of flexible expansion and contraction, ensuring that the electrode can Adapt to various uneven rock surfaces, avoiding the phenomenon that the electrode is blocked by the rock surface protrusions and broken or the phenomenon of poor contact due to depressions occurs when the cutter head rotates.

4. The present invention provides a mechanism that can realize real-time monitoring of electrode positions, realizes real-time data collection and simultaneously records the location of the group of data measurement electrodes, and provides effective position information for data processing.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present application, and the schematic embodiments and descriptions of the present application are used to explain the present application, and do not constitute improper limitations to the present application.

Fig. 1 (a) is the front view of the variable direction electrode device of the present invention;

Fig. 1 (b) is the side view of variable direction electrode device of the present invention;

Figure 1(c) is a top view of the variable direction electrode device of the present invention;

Fig. 1 (d) is a detailed view of the variable direction device of the present invention;

Fig. 2 is the figure of elastic expansion device of the present invention;

Fig. 3 is a diagram of the variable resistance positioning device of the present invention;

Fig. 3 (a) is the cutter head electrode arrangement diagram of the present invention;

Among them, 1. Electrode rod, 2. Contact electrode device, 3. Bearing plate, 4. Wheel frame, 5. Bearing, 6. Shaft, 7. Wheel end, 8. Retaining ring, 9. Washer, 10. Fixing device, 11. Hydraulic shrinking device, 12. Elastic pushing device, 13. Detection electrode, 14. Scribing, 15. Ring rheostat device, 16. Wire, 17. Ring wire, 18. Current monitoring device, 19. Power supply Mechanism, 20. TBM cutter head, 21. cutter.

detailed description:

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

It should be pointed out that the following detailed description is exemplary and intended to provide further explanation to the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

An electrode system and technology that can effectively realize the detection during the excavation process of the cutter head. The system is composed of a variable direction electrode mechanism, an elastic expansion device and a variable resistance positioning mechanism.

The variable direction electrode mechanism includes a contact electrode device, a direction changing transmission device and a fixed protection device. The contact electrode device is in direct contact with the rock surface, so it is required to have good wear resistance and play the role of the main exciting electric field, so it is required to have good conductivity. The direction-changing transmission device is mainly composed of wheel shaft rotating bearings and rod shaft rotating bearings, etc., which enable the contact electrode device to freely rotate under control to adapt to the rotation of the cutter head. The fixed protection device is mainly composed of bearing plates, rubber gaskets, etc., which play a role in strengthening and protecting the electrodes.

In order to solve the problem in the background technology that the rock face may be broken and rough, the cutter head will directly contact with such rock face during the rotating excavation process. At the same time, the existing electrode device is a fixed electrode, which does not have the ability to roll. When the cutter head rotates, the electrode will produce sliding friction with the rock surface, resulting in wear and damage of the electrode head, which is difficult to apply.

The contact electrode device adopts a wheel design, which changes sliding friction into rolling friction, which greatly reduces the friction between the electrode and the rock surface. The material is tungsten-copper alloy. Tungsten-copper alloy has good electrical conductivity and certain wear resistance. In addition, it also has high high-temperature strength and certain plasticity. High-temperature strength can prevent the heat generated by friction from damaging the mechanism, and plasticity can be guaranteed. Good contact between electrodes and rock face.

The direction-changing transmission device is composed of a wheel shaft rotary bearing and a rod shaft rotary bearing, etc. The wheel shaft rotary bearing ensures that the wheel-shaped contact electrode device can freely rotate around the center of the wheel shaft, and plays the role of changing sliding friction into rolling friction. The rod shaft rotation bearing is arranged in the electrode rod, and connects the electrode rod and the contact electrode device, so that the device can rotate 360° horizontally in the plane where it is located, so as to adapt to the rotation of the cutter head.

The fixed protection device is mainly composed of a wheel frame, a rubber gasket and other mechanisms. The wheel frame plays the role of supporting the wheel contact electrode device. The rubber gasket slows down the friction between the nut and the retaining ring, and is located between the electrode rod and the contact electrode. Rubber spacers between the units also serve to reduce friction and cushion shocks.

In order to solve the problem that the electrode often encounters uneven rock surfaces when it is extended, since the current electrode is still controlled by a hydraulic cylinder, the overall design is rigid and cannot be stretched at will. It is difficult to rebound and feed the knife at any time when facing such rock surfaces. Disc prior art problems.

The elastic stretchable electrode is composed of a hydraulic contraction device and an elastic propulsion device. The elastic propulsion device is assembled behind the electrode and is closely connected with the inside of the cutter head, and the hydraulic shrinkage device is assembled around the electrode, which can exert force on the retraction of the electrode.

The hydraulic shrinking device is composed of a set of hydraulic cylinders, and a set includes two hydraulic cylinders, which are symmetrically distributed on both sides of the electrode rod and connected to the electrode rod to provide force for the retraction of the electrode.

The elastic propulsion device is composed of a high elastic spring, which is fixed at the rear of the electrode rod, connected with the tail of the electrode rod, and closely connected with the cutter head at the other end.

The rheostat positioning device is composed of an annular rheostat device, a control circuit device, and a signal processing and transmission device. An ammeter is used to monitor the current in the circuit, and then monitor the resistance value of the rheostat device, so as to achieve real-time monitoring of the electrode position. The device is installed on the inner side of the cutterhead back panel. And it is monitored and controlled by the main control computer.

The annular rheostat device is composed of an annular sliding rheostat, which surrounds the center point of the cutter head and is installed on the inner side of the back panel of the cutter head. The annular rheostat device is not a complete ring to avoid the situation that the resistance value may not be unique during the measurement. The occurrence of detection provides the material basis for detection for the entire set of institutions.

The control circuit device is composed of a ring rheostat device, a power supply mechanism, a current detection device, wires and the like. The connecting wires are divided into two types: movable wires and fixed wires. The wires connecting the electrodes and the ring rheostat device are movable wires, which rotate with the rotation of the cutter head and the electrodes, and connect the wires of the ring rheostat device, the power supply mechanism, and the current detection device. It is a fixed wire. A ring wire identical to the path is arranged on the path of the rotating movement of the electrode to form a closed loop.

The signal processing and transmission device is composed of a transmission cable and a signal processing mechanism, and the transmission cable connects the current detection device and the signal processing mechanism. The signal processing mechanism is placed in the main control room, and a set of signal processing programs are built in, which can convert the returned current information into resistance information.

A technical method that can realize the detection during the rotation of the cutter head. The variable direction electrode mechanism can rotate adaptively with the movement of the cutter head. When the mechanism is not working, it will be retracted in the cutter head, and it will pop up when it is working. The contact electrode device is in good contact with the rock face. The use of tungsten-copper alloy material with good conductivity ensures that the contact electrode device meets the basic requirements of electrical exploration. The wheel design avoids excessive wear of the electrode tip during the rotation of the cutter head, reduces loss and improves detection efficiency.

The elastic expansion device is specifically the elastic propulsion device arranged at the end of the electrode rod, which is in a compressed state when the electrode is retracted. In order to keep the spring in a compressed state, the hydraulic contraction device designed around the electrode rod compresses the spring when the electrode is retracted. When the electrode needs to be ejected, the force of the hydraulic cylinder is gradually slowed down so that the spring rebounds slowly, and the electrode ejects to contact the rock surface. At this time, the spring is still in a partially compressed state. If the cutter head encounters a concave-convex interface when it rotates, at the concave interface, the electrode can be pressed against the rock surface by the driving force exerted by the spring that is still in a compressed state; is compressed. Between spring compression and release back and forth, it ensures good contact between the electrode and the uneven rock surface, and at the same time protects the electrode from being damaged due to the unevenness of the rock surface.

When the electrode is retracted, the hydraulic cylinder will add force, so that the spring will be compressed again, and the electrode will be retracted.

In order to solve the problem that the cutter head is always in a rotating state during the excavation process, it is difficult to locate the electrode position in real time when the electrode is working, which will lead to the problem that the position coordinates of the collected data cannot be accurately located.

The present invention uses a rheostat positioning device to monitor the electrode position in real time, uses a polar coordinate system for positioning, takes the center of the cutter head as the center of the polar coordinate system, and takes the horizontal direction as 0° and 180° angles. When the cutter head rotates, the movable wire rotates at the same time. When the cutter head is in different positions, the resistance value of the sliding rheostat also changes accordingly. The current detection device installed in the circuit can detect the magnitude of the current in the circuit to monitor the resistance. value changes, and deduce the position of the tracking electrode.

During the excavation process of TBM cutter head rotation, the electrodes can record the distance from each electrode to the center point while collecting in real time, so as to provide the necessary information for radial positioning.

As a typical embodiment, as shown in FIG. 1( a )- FIG. 1( d ), the device includes two parts, one is an electrode rod 1 , and the other is a contact electrode device 2 . Among them, the contact end of the rubber electrode is changed to a wheel-type contact electrode device 2, and rolling friction is used instead of sliding friction; the wheel-type end is allowed to rotate 360 degrees horizontally in the plane of the rock surface; The retaining ring 8, bearing 5, shaft frame 4, washer 9, and nut 10 are connected in sequence to ensure tight connection. Graphite lubricant can be used between shaft 6 and bearing 5. The good lubricity of graphite lubricant makes the wheel electrode end The part can rotate flexibly, and the graphite lubricant has excellent conductivity (close to iron) without affecting the basic conductivity of the electrode. In terms of materials, the square plate 3, the axle frame 4, the bearing 5, the shaft 6, the universal wheel 7, the nut 10, and the retaining ring 8 are all made of tungsten-copper alloy, and the tungsten-copper alloy has good conductivity and greater wear resistance , can meet the needs of long-term use. Gasket 9 is a wear-resistant sealing rubber ring.

During detection, the wheel head 7 is in contact with the rock surface. At this time, due to the effect of the reversing transmission device, it is assumed that the wheel head 7 is subjected to an ordinary force F, which can be decomposed into a force Fz perpendicular to the cutter head and a force Fz parallel to the cutter head. The force Fxy.Fz on the cutterhead plane can be ignored, and Fxy can be decomposed into the force Fy along the wheel axis and the force Fx perpendicular to the wheel axis. Because there are two bearings, the universal wheel can be integrated to rotate along the Z axis, or the wheel can be rotated along the wheel axis Y rotate. Because the point of action of the force is generally not on the Z axis, Fxy will generate a torque on the xy plane, so the universal wheel will rotate along the Z axis. When the universal wheel rotates until the line where Fxy is located passes through the Z axis, the torque will be zero. The direction of the universal wheel is stable and does not rotate, so the wheeled head 7 can freely rotate 360° in the plane where the rock face is located, so the wheeled head 7 can adapt to the motion of the cutter head. The contact electrode device 2 is used for detection, and the detection information is transmitted in the form of current. The current passes through the wheel contact device 7, the shaft 6, the bearing 5, the wheel frame 4, and the square plate 3 in sequence, and finally enters the electrode rod 1. The current passes through and is connected to the main control room. The cables are used for transmission, and converted into geological information data in the detection system in the main control room, and stored in the computer.

As shown in Fig. 2, when detection is required, the pressure of the hydraulic contraction device 11 is gradually released, and the electrode is stretched out under the action of the force of the elastic pushing device 12, and the wheeled head 7 is in good contact with the rock surface, and detection begins. When encountering uneven rock faces, the elastic telescopic device can ensure good adaptability of the electrodes to the rock faces. When encountering a protrusion, the electrode is squeezed, and the elastic pushing device 12 is forced to compress, and the electrode is partially retracted; when encountering a depression, the elastic pushing device 12 continues to push out the electrode to ensure the contact between the electrode and the rock face. When the contact electrode device 2 is not working and the electrode is to be withdrawn, the hydraulic contraction device 11 is gradually pressurized, the elastic pushing device 12 is forced to shrink, the electrode is recovered, and the contact electrode device 2 is retracted in the cutter head 20 . The wheel-type end uses rolling friction instead of sliding friction, and is made of tungsten-copper alloy material, which ensures good electrical conductivity. The good wear resistance of tungsten-copper alloy itself can effectively avoid the wear and damage of the electrode tip caused by complex terrain. Extend electrode life.

As shown in Fig. 3, the position of the electrode is mainly realized by two sets of systems: the circumferential positioning of the ring rheostat device and the radial positioning relying on the distance between the electrode 13 and the center point of the cutterhead. This device is installed at the tail end of the electrode rod and adopts polar coordinate positioning. The center of the cutter head 20 is the center of the polar coordinate system, and the horizontal direction is 0° and 180°. The ring rheostat device 15 is connected by wires 16. The electrode rod 1 is rigidly connected to the ring rheostat device 15 through the scribe 14 to form a sliding rheostat. The scribe 14 adopts an unbendable straight wire, and the ring wire 17 assists in forming a closed circuit. The ring varistor device 15 and the ring wire 17 are concentric circles. The ring varistor device 15 is bundled with conductive coils, and the varistor ring 15 is interrupted 1 mm below the contact position between the ring varistor device 15 and the ring inner wire 17 to avoid multi-solution of the measured resistance.

Circumferential positioning principle: when the cutter head 20 rotates, the scribe 14 rigidly connected to the electrode rod 1 also rotates at the same time, and the scribe 14 moves on the sliding rheostat ring 15 accordingly. When the scribe 14 moves into the sliding rheostat ring 15, the position, the resistors in the circuit have different resistance values, record the resistance value of the ring rheostat device at this time as r, and the total resistance value of the ring rheostat device is R. The current monitoring device 18 monitors the current in the circuit. The reading of the current monitoring device is I, and the voltage provided by the power supply device is U, regardless of the wire resistance. According to I=U/r, the value of r is obtained. According to r/R=θ/360°, the polar coordinate parameter θ is calculated, and then the radial distance L of the electrode rod 1 on the cutter head 20 is used for further positioning. The positioning of the electrode 13 is realized by polar coordinates (L, θ). Combining the information transmitted by the electrode 13 back to the main control room and the speed of the cutter head, the position of the electrode is returned to the position when it was excited or received the electrical signal, and the electrode position can be realized. The real real-time positioning can accurately obtain the geological information of the front face, so as to intuitively and accurately understand the geological conditions of the front face.

The content not described in detail in the present invention is the prior art, and will not be repeated here.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (10)

1. A tunnel boring machine airborne resistivity method advance detection real-time acquisition electrode system is characterized in that: it includes a variable direction electrode mechanism, an elastic telescopic device and a variable resistance positioning mechanism, wherein: The variable-direction electrode mechanism includes a contact electrode part and a direction-changing transmission part. The contact electrode part contacts the electrode and directly contacts the rock surface during the excavation process to excite an electric field. The shaft rotates freely, converting the sliding friction in contact with the rock surface into rolling friction; The elastic telescopic device includes a power contraction part and an elastic propulsion part. The elastic propulsion part is assembled behind the electrode and is closely connected with the inside of the cutter head. The power contraction part is arranged on the edge of the electrode to apply force to the indentation of the electrode to overcome the elastic propulsion the spring force exerted by the part; The rheostat positioning mechanism includes a sliding rheostat, which is positioned with the polar coordinate system as the coordinate axis, and the center of the polar coordinate system is taken as the center of the cutter head, and the different positions of the cutter head are determined by detecting the change of the resistance value of the sliding rheostat. Estimate the location of the tracking electrodes. 2. A kind of tunnel boring machine airborne resistivity method advanced detection real-time acquisition electrode system as claimed in claim 1, it is characterized in that: described direction change transmission part comprises wheel frame, wheel shaft rotating bearing and wheel type end, so One end of the wheel frame is arranged at the tail end of the contact electrode, and the other end is connected to the central axis of the wheel end through the wheel shaft rotation bearing, so that the electrode rod can freely rotate around the center axis of the wheel end. 3. A kind of tunnel boring machine airborne resistivity method advanced detection real-time acquisition electrode system as claimed in claim 1, it is characterized in that: said contact electrode part will detect The information is transmitted to the electrode rod in the form of electric current; or the material of the contact electrode part is tungsten copper alloy. 4. A tunnel boring machine airborne resistivity method advance detection real-time acquisition electrode system as claimed in claim 1, characterized in that: the variable direction electrode mechanism also includes a fixed protection device, and the fixed protection device includes a bearing plate and an elastic washer, the bearing plate is arranged at the junction between the end of the electrode rod and the direction-changing transmission member, and the elastic washer is arranged on the elastic washer. 5. A tunnel boring machine airborne resistivity method advance detection real-time acquisition electrode system as claimed in claim 1, characterized in that: the power contraction part is a hydraulic contraction device, including two hydraulic cylinders, symmetrically distributed on the electrodes The two sides of the rod are connected to the electrode rod to provide force for the retraction of the electrode. 6. A tunnel boring machine airborne resistivity method advance detection real-time acquisition electrode system as claimed in claim 1, characterized in that: the rheostat positioning mechanism includes an annular rheostat device, a control circuit device, and signal processing and transmission The device uses an ammeter to monitor the current in the loop to monitor the resistance of the ring rheostat device to achieve real-time monitoring of the electrode position. The rheostat positioning mechanism is installed inside the back panel of the cutterhead. 7. A tunnel boring machine airborne resistivity method advance detection real-time acquisition electrode system as claimed in claim 6, characterized in that: the annular rheostat device is composed of an annular sliding rheostat, which surrounds the center point of the cutter head , installed on the inside of the back panel of the cutter head, the electrode rod is rigidly connected to the ring rheostat device through scribing to form a sliding rheostat. 8. A tunnel boring machine airborne resistivity method advance detection real-time acquisition electrode system as claimed in claim 6, characterized in that: the control circuit device includes a power supply mechanism, a current detection device and wires, and the wires are divided into movable wires There are two kinds of wires, the wire connecting the electrode and the ring rheostat device is a movable wire, which rotates with the rotation of the cutter head and the electrode, and the wire connecting the ring rheostat device, the power supply mechanism and the current detection device is a fixed wire. 9. A kind of tunnel boring machine airborne resistivity method advanced detection real-time acquisition electrode system as claimed in claim 8, it is characterized in that: on the path of electrode rotation motion, a ring wire identical to the path is set, for forming a closed circuit; Or the signal processing and transmission device includes a transmission cable and a signal processor, the transmission cable connects the current detection device and the signal processor, and the signal processor converts the returned current information into resistance information. 10. The working method based on the device according to any one of claims 1-9, characterized in that: the variable direction electrode mechanism rotates adaptively with the movement of the cutter head, and is retracted in the cutter head when the mechanism is not working , pop up during work, when the electrode needs to pop up, the power contraction part gradually slows down to make the elastic propulsion part rebound, the electrode pops up and contacts the rock surface, if the cutter head encounters a concave-convex interface when rotating, the electrode is still in compression at the concave interface The pushing force exerted by the elastic propulsion part of the state is close to the rock surface. At the convex interface, the electrode is squeezed and partially retracted, and the elastic propulsion part is recompressed to ensure that the contact electrode is always in good contact with the rock surface. The positioning mechanism is used to monitor the position of the electrode in real time, and the polar coordinate system is used for positioning. The center of the cutter head is the center of the polar coordinate system, and the current in the circuit is detected to monitor the change of the resistance value and calculate the position of the tracking electrode.