CN117890394A - Shield cutterhead mud cake detection device and detection method - Google Patents

Abstract

The application provides a device and a method for detecting mud cake of a shield cutter disc, belongs to the field of shield cutter disc detection, and solves the problems of large detection error and low efficiency of mud cake of the shield cutter disc. The detection device comprises: the soil blocking box is fixedly provided with a telescopic motor and an opening, the telescopic end of the telescopic motor is connected with a probe, one end of the probe, which is away from the telescopic motor, is provided with a plurality of probes, and the probes are aligned with the opening; the data sampling device and the data exciter are both arranged outside the soil blocking box, the data sampling device is connected with the data exciter, the data exciter is connected with a coaxial cable, the coaxial cable is provided with BNC connectors, each probe is respectively connected with a connecting wire, the connecting wires extend to the outside of the soil blocking box and are connected with a data transmission line, and the other end of the data transmission line is connected with the BNC connectors; the probe can move outside the soil retaining box along with the change of the telescopic quantity of the telescopic end of the telescopic motor. The application can improve the efficiency and accuracy of mud cake detection.

Description

Shield cutterhead mud cake detection device and detection method

Technical Field

The present application belongs to the technical field of shield cutter head detection, and specifically relates to a shield cutter head mud cake detection device and detection method.

Background technique

With the increase in the demand for urban transportation in my country, the use of large-diameter slurry shields to excavate underground transportation pipelines has become the main direction of underground space construction. The use of large-diameter slurry shields for excavation will encounter various construction problems, especially when the shield is constructed in composite strata or soft clay. The soil and slurry mixture on the cutter disc adheres to the cutter disc during the rotation of the cutter disc, resulting in mud cakes and other construction problems. Mud cakes on the shield cutter disc not only affect the service life of the tool, but also significantly extend the shield construction period. It is a type of problem that is more difficult to deal with in shield construction. Most of the existing shield cutter disc mud cake monitoring methods use machine sampling, manual detection, or methods based on engineering experience to determine whether the shield cutter disc has mud cakes. Such methods have the disadvantages of low efficiency and large error in results.

Therefore, there is an urgent need for a detection device that can be used on the cutter head of a large-diameter slurry shield to realize dynamic monitoring of the mud cake on the cutter head of the shield.

Summary of the invention

In view of this, the present application provides a shield cutter head mud cake detection device and detection method, which are used to improve the problems of large error and low efficiency in shield cutter head mud cake detection.

The technical solution adopted by this application to solve the above technical problems is:

In a first aspect, the present application provides a shield cutterhead mud cake detection device, comprising:

A soil retaining box, wherein a telescopic motor is fixed on one side of the soil retaining box, and an opening is provided on the other side. A probe is connected to the telescopic end of the telescopic motor, and a plurality of probes are provided at one end of the probe away from the telescopic motor, and the probes are arranged to match the opening;

A data sampler and a data stimulator, both of which are arranged outside the soil retaining box, the data sampler is connected to the data stimulator via a coaxial line, the data stimulator is connected to a coaxial cable, a BNC connector is arranged at the end of the coaxial cable, each of the probes is respectively connected to a connecting wire, the connecting wire extends to the outside of the soil retaining box and is connected to a data transmission line, the other end of the data transmission line is connected to the BNC connector;

The probe can move outside the soil retaining box as the telescopic amount of the telescopic end of the telescopic motor changes.

In some embodiments of the present application, the soil retaining box includes a bottom plate and a cover plate, the bottom plate and the cover plate are arranged opposite to each other, and the opening is formed on the cover plate.

In some embodiments of the present application, the connecting wire passes through the bottom plate and extends to the outside of the soil retaining box, and is electrically connected to the data exciter and the data sampler in sequence through the data transmission line.

In some embodiments of the present application, a rubber ring is embedded in the opening, and the rubber ring has an axial direction. Along the axial direction, two sides of the rubber ring extend to two sides of the opening respectively and are fixed to the cover plate.

In some embodiments of the present application, the telescopic motor is connected to a flat plate connector, which is fixed to the base plate via a hexagonal threaded connector. The wires of the telescopic motor pass through the base plate, extend to the outside of the soil retaining box, and are connected to a telescopic motor power supply.

In some embodiments of the present application, the probe includes a connecting plate, one side of which is fixedly connected to the tail of the probe, and the other side is provided with two oppositely arranged joints; the telescopic end of the telescopic motor is provided with a telescopic motor joint, the telescopic motor joint extends between the two joints, and the two sides of the telescopic motor joint are respectively connected to the two joints.

In some embodiments of the present application, when the telescopic end of the telescopic motor has a minimum telescopic amount, the head of the probe is exposed from the opening.

In some embodiments of the present application, the head of the probe is conical.

In a second aspect, an embodiment of the present application further provides a shield cutter disc mud cake detection method, which is applied to the shield cutter disc mud cake detection device as described in the first aspect, and the detection method comprises:

Installing the shield cutter disc mud cake detection device on the cutter disc and starting the shield cutter disc mud cake detection device;

Control the telescopic motor to push the probe to move toward the opening, and the probe moves in a direction away from the telescopic motor and is inserted into the detection soil until the telescopic end of the telescopic motor reaches a maximum telescopic amount;

Control the data exciter to generate a pulse electromagnetic wave and output it through the probe, and transmit the obtained reflection signal to the data sampler, and the data sampler generates a waveform curve according to the reflection signal;

According to the waveform curve, the water content of the detection soil is analyzed and detected, and the condition of mud cake on the shield cutter head is predicted.

In some embodiments of the present application, before the step of analyzing and detecting the water content of the detected soil and predicting the condition of the shield cutter head forming mud cake according to the waveform curve, the method further includes:

When the waveform curve tends to be stable, the telescopic end of the telescopic motor is controlled to contract, the probe is pulled back to the initial position, and the probe is retracted toward the soil retaining box through the opening until the telescopic amount of the telescopic motor reaches the minimum telescopic amount.

In summary, due to the adoption of the above technical solution, this application has at least the following beneficial effects:

The present application provides a shield cutter disc mud cake detection device and detection method, which mainly uses a telescopic motor to drive the probe to move telescopically, so that the probe can be inserted into the detection soil, and the detection of different depths of the detection soil is realized. The detection function also needs to be realized by electrically connecting the probe with a data sampler and a data stimulator, generating a pulse electromagnetic wave by using the data stimulator, and then outputting it through the probe to obtain a reflected signal to feed back to the data sampler, generating a waveform curve, and analyzing and monitoring the mud cake in real time according to the waveform curve. In detail, it is mainly through the use of a data sampler, a data stimulator and a probe to be electrically connected, and then using the data stimulator to emit a pulse electromagnetic wave, and transmitting the pulse electromagnetic wave to the detection soil through the probe, so as to realize the detection of the detection soil. When the detection soil receives the pulse electromagnetic wave, it will produce a certain reaction, which is a reflected signal, and then transmitted to the data sampler through the probe. The data sampler generates a waveform curve according to the reflected signal. The waveform curve can be used to monitor the water content of the detection soil, and then the current mud cake formation situation can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments are briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present application, but are not intended to limit the present application, wherein:

FIG1 is a schematic diagram of the structure of a shield cutterhead mud cake detection device provided in an embodiment of the present application;

FIG2 is an internal structure diagram of a shield cutterhead mud cake detection device provided in an embodiment of the present application;

FIG3 is a three-dimensional schematic diagram of the interior of the soil retaining box provided in an embodiment of the present application;

FIG4 is a schematic structural diagram of a flat plate connector provided in an embodiment of the present application;

FIG. 5 is a schematic diagram of the structure of a probe provided in an embodiment of the present application.

Description of reference numerals:

1. Data sampler; 2. Data stimulator; 3. Coaxial line; 4. Coaxial cable; 5. BNC connector; 6. Data transmission line; 7. Telescopic motor power supply; 8. Soil retaining box; 9. Base plate; 10. Probe; 11. Cover plate; 12. Telescopic motor; 13. Telescopic motor connector; 14. Extended hexagonal threaded connector; 15. Rubber ring; 18. Flat plate connector; 19. Hexagonal threaded connector; 23. Positioning groove; 24. Connecting plate; 25. Probe; 28. Connector; 30. Connecting wire.

Detailed ways

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

In the description of this application, it should be understood that the words "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

In this application, the word "exemplary" is used to mean "used as an example, illustration, or description". Any embodiment described in this application as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is given to enable any technician in the field to implement and use the present application. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present application can be implemented without using these specific details. In other instances, known structures and processes are not described in detail to avoid obscuring the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles disclosed in the present application.

Please refer to Figures 1 to 5. The embodiment of the present application provides a shield cutter head mud cake detection device, including:

A soil retaining box 8, a telescopic motor 12 is fixed on one side of the soil retaining box 8, and an opening is provided on the other side. The telescopic end of the telescopic motor 12 is connected to a probe 10, and a plurality of probes 25 are provided on the end of the probe 10 away from the telescopic motor 12, and the probes 25 are arranged in alignment with the opening. It should be noted that the soil retaining box 8 is generally arranged at the front of the shield machine to prevent soil collapse and mud outflow, and can also provide support to ensure the stability of the shield machine during excavation.

A data sampler 1 and a data stimulator 2, both of which are arranged outside the soil retaining box 8, the data sampler 1 is connected to the data stimulator 2 via a coaxial line 3, the data stimulator 2 is connected to a coaxial cable 4, a BNC (Bayonet Nut Connector) connector 5 is provided at the end of the coaxial cable 4, each of the probes 25 is respectively connected to a connecting wire 30, the connecting wire 30 extends to the outside of the soil retaining box 8 and is connected to a data transmission line 6, the other end of the data transmission line 6 is connected to the BNC connector 5;

The probe 25 can move outside the soil retaining box 8 as the telescopic amount of the telescopic end of the telescopic motor 12 changes.

The technical solution provided by the present application is mainly to drive the probe 25 to move telescopically by using the telescopic motor 12, so that the probe 25 can be inserted into the detection soil to detect different depths of the detection soil. The detection function also needs to be realized by electrically connecting the probe 25 with the data sampler 1 and the data stimulator 2, generating pulse electromagnetic waves by using the data stimulator 2, and then outputting them through the probe 25 to obtain a reflected signal to be fed back to the data sampler 1, generating a waveform curve, and analyzing and monitoring the mud cake in real time according to the waveform curve. In detail, it is mainly to electrically connect the data sampler 1, the data stimulator 2 and the probe 25, and then use the data stimulator 2 to emit pulse electromagnetic waves, and transmit the pulse electromagnetic waves to the detection soil through the probe 25, so as to detect the detection soil. When the detection soil receives the pulse electromagnetic wave, it will produce a certain reaction, which is a reflected signal, which is transmitted to the data sampler 1 through the probe 25. The data sampler 1 generates a waveform curve according to the reflected signal. The waveform curve can be used to monitor the water content of the detection soil, and then the current mud cake formation situation can be obtained.

It should be noted that the detection and analysis of the shield cutterhead mud cake detection device is mainly based on the TDR (Time-Domain Reflectometry) principle. The so-called TDR principle refers to time domain reflection technology, a remote control measurement technology for analyzing reflected waves, and the status of the measured object is grasped through the remote control position; the principle of TDR (Time Domain Reflectometry) time domain reflection technology is that when the signal is transmitted in a certain transmission path, when the impedance changes in the transmission path, part of the signal will be reflected, and the other part of the signal will continue to be transmitted along the transmission path. TDR calculates the impedance change by measuring the voltage amplitude of the reflected wave; at the same time, as long as the time value from the reflection point to the signal output point is measured, the position of the impedance change point in the transmission path can be calculated. The TDR time domain reflectometer sends a low-voltage pulse to the cable under test, and reflections will be seen when the impedance changes in the cable. The TDR time domain reflectometer TDR tests the time from the release of the reflection to the release of the low-voltage pulse. By measuring the time and knowing the propagation speed of the pulse, the distance to the reflection can be calculated, thereby obtaining the cable length or the distance to the fault point. Information about the impedance change or fault type that may occur in the cable can also be judged based on different transmission waveforms.

For ease of understanding, the use of the waveform curve to monitor the moisture content of the detected soil and then obtain the current mud cake formation situation is further introduced in detail:

First, the data exciter 2 will emit a short pulse electromagnetic wave signal, which will be transmitted to the soil through the probe 10; then, the electromagnetic wave signal propagates in the soil, and when encountering different media or water changes in the soil, part of the signal will be reflected back. These reflected signals contain information inside the soil; then, the probe 25 will receive these reflected signals and transmit them back to the data sampler 1 for processing; then, the data sampler 1 will generate a waveform curve based on the received reflected signal, which reflects the change in the dielectric constant in the soil; then, by analyzing the waveform curve, we can understand the distribution of water content in the soil. The relationship between soil moisture content and reflected signals is that the higher the moisture content, the greater the amplitude of the reflected signal, because moisture will change the dielectric constant of the soil. Moisture has a higher dielectric constant during the propagation of electromagnetic waves, and a medium with a larger dielectric constant will cause the electromagnetic waves to be damped and reflected more. Specifically, when electromagnetic waves pass through the soil, part of the energy will be absorbed by the moisture in the soil, causing the electromagnetic waves to weaken during the propagation process in the soil. The higher the moisture content, the more moisture there is in the soil, so the electromagnetic wave will be damped during propagation, and the amplitude of the reflected signal will be relatively large. In addition, the higher the moisture content, the greater the effective dielectric constant in the soil. The increase in the effective dielectric constant will cause the propagation speed of electromagnetic waves in the soil to slow down, thereby increasing the chance and amplitude of reflection. Therefore, in general, the higher the moisture content, the greater the amplitude of the reflected signal. Finally, based on the moisture content of the soil, we can predict the formation of the mud cake. The relationship between the formation of the mud cake and the moisture content of the soil is: soil with a higher moisture content will cause the formation of the mud cake to be obstructed or incomplete, and soil with a lower moisture content is conducive to the formation of the mud cake.

It should be noted that the dielectric constant of soil is a physical quantity that describes the properties of soil for electromagnetic wave propagation. The dielectric constant is the dielectric constant of a medium relative to a vacuum. The dielectric constant of soil is affected by factors such as the moisture content in the soil, the soil type, and the soil particle structure. Generally speaking, the higher the moisture content in the soil, the greater the dielectric constant, because moisture has a higher dielectric constant for electromagnetic waves. In contrast, the dielectric constant of soil particles is lower. This is because moisture fills the gaps between soil particles, increases the conductivity of the soil, and thus increases the overall dielectric constant. Specifically, different types of soil have different response characteristics to the propagation of electromagnetic waves. For example, sandy soil usually contains less moisture and therefore has a lower dielectric constant; while clay usually contains more moisture and has a higher dielectric constant. In the detection of mud cake on the shield cutter head, by measuring the change in the dielectric constant of the soil, the moisture content of the soil can be inferred, and then the formation of mud cake can be predicted.

The following embodiments are described based on the contents disclosed in the above embodiments.

As an embodiment A, a shield cutter head mud cake detection device based on the TDR principle includes: a data sampler 1, a data stimulator 2 and a soil retaining box 8. The data sampler 1 and the data stimulator 2 are both arranged outside the soil retaining box 8. One side of the soil retaining box 8 is a bottom plate 9, and a telescopic motor 12 is fixed on the bottom plate 9.

As shown in FIG4 , the telescopic motor 12 is welded and connected with a flat plate connector 18, and the flat plate connector 18 is fixed to the bottom plate 9 by arranging four hexagonal threaded connectors 19 at the four corners, and the wires of the telescopic motor 12 pass through the bottom plate 9 and are connected to the telescopic motor power supply 7 outside the retaining box 8. Furthermore, a positioning groove 23 is provided on the bottom plate 9, and the flat plate connector 18 is arranged in the positioning groove 23. The positioning groove 23 is used to realize the positioning and auxiliary fixing of the flat plate connector 18 during the installation process, thereby improving the installation efficiency.

As shown in FIG5 , the telescopic end of the telescopic motor 12 is connected to a probe 10 , and three probes 25 are provided at the front end of the probe 10 to form a three-needle probe, and the heads of the probes 25 are conical.

As shown in Figure 3, the probe 10 includes a flat connecting plate 24, one side of the connecting plate 24 is fixedly connected to the tail of the probe 25, and the other side is provided with two parallel joints 28, the connecting plate 24 and the joints 28 are both made of insulating materials, and the connecting plate 24 and the joints 28 in this embodiment are both made of epoxy resin; the telescopic end of the telescopic motor 12 is provided with a telescopic motor joint 13, the telescopic motor joint 13 extends between the joints 28, the telescopic motor joint 13 and the joints 28 on both sides are connected and fixed together through an extended hexagonal threaded connector 14, and the telescopic motor 12 is perpendicular to the extended hexagonal threaded connector 14.

The side opposite to the bottom plate 9 is a cover plate 11, which is welded to the soil retaining box 8. The cover plate 11 is provided with an opening that matches the probe 25. When the telescopic end of the telescopic motor 12 is extended, the probe 10 is driven to move toward the opening of the soil retaining box 8, and the front end of the probe 25 extends from the opening.

As shown in Figures 1 and 2, the data sampler 1 is connected to the data exciter 2 via a coaxial cable 3, the data exciter 2 is connected to a coaxial cable 4, a BNC connector 5 is provided at the end of the coaxial cable 4, each probe 25 is respectively connected to a connecting wire 30, the connecting wire 30 is connected to a data transmission line 6 outside the retaining box 8, and the other end of the data transmission line 6 is connected to the BNC connector 5.

As another embodiment B, this embodiment B proposes a more specific shield cutter head mud cake detection device based on the TDR principle on the basis of embodiment A.

A rubber ring 15 is embedded in the opening, and the rubber ring 15 has an axial direction. Along the axial direction, both sides of the rubber ring 15 extend to both sides of the opening and are fixed to the cover plate 11. The rubber ring 15 has good elasticity, so the rubber ring 15 can always fill the gap between the probe 25 and the opening to prevent soil and groundwater from invading the retaining box 8 and affecting the detection work of the detection device.

When the telescopic length of the telescopic end of the telescopic motor 12 is at the minimum value (i.e., the telescopic amount is the minimum), the head of the probe 25 is exposed from the opening, and the thickness of the rubber ring 15 in the direction of the opening diameter is relatively large. When the probe 25 moves out of the opening as a whole, the rubber ring 15 is stretched open, and the thickness of the rubber ring 15 in the direction of the opening diameter is correspondingly reduced.

It should be noted that the parts in this embodiment B that are the same or similar to those in embodiment A can be referenced to each other and will not be repeated in this application.

As another embodiment C, the method for using the shield cutter head mud cake detection device based on the TDR principle proposed in embodiment A and embodiment B comprises the following steps:

S1. Installing a shield cutter disc mud cake detection device on the cutter disc and starting the shield cutter disc mud cake detection device;

S2, control the telescopic motor to push the probe to move toward the opening direction, and the probe moves in the direction away from the telescopic motor and is inserted into the detection soil until the telescopic end of the telescopic motor reaches the maximum telescopic amount;

S3, controlling the data exciter to generate a pulse electromagnetic wave and output it through the probe, and transmitting the obtained reflected signal to the data sampler, and the data sampler generates a waveform curve according to the reflected signal;

S4. Analyze and detect the moisture content of the detected soil and predict the condition of mud cake on the shield cutter head according to the waveform curve.

For the above steps, in detail: first, the shield cutter disc mud cake detection device is installed on the cutter disc; second, the shield machine enters the detection position, stops running, and starts the shield cutter disc mud cake detection device; third, the telescopic motor 12 pushes the probe 10 forward, and the probe 25 extends from the opening and is inserted into the detection soil until the telescopic motor 12 travels to the maximum stroke (i.e., the maximum telescopic amount); fourth, the data exciter 2 generates a pulse electromagnetic wave and outputs it through the probe 25, and the pulse electromagnetic wave in the reflected signal obtained by the probe 25 is transmitted to the data sampler 1, and the signal sampler 1 collects the reflected pulse electromagnetic wave through the coaxial line 3 to form a waveform curve; fifth, according to the collected information obtained by the data sampler 1, the water content of the soil is analyzed and detected by using the principle that the dielectric constants of different soils are different, and then the situation of the shield cutter disc mud cake is predicted.

As mentioned in the above embodiment, the probe 25 is inserted into the detection soil body for detection. Compared with directly detecting outside the soil body through the probe 25, it has at least the following beneficial effects: although the electromagnetic waves emitted by the probe 25 can be propagated without a medium, when the electromagnetic waves encounter a medium, some interactions will occur, such as the absorption, scattering, reflection, and refraction of the electromagnetic waves by the medium. When electromagnetic waves are directly emitted outside the soil, the interface between the air and the soil will cause the reflection and scattering of part of the signal, making the received signal weakened and confused. By inserting the probe 25 into the soil, the interaction between the electromagnetic waves and the soil can be better controlled, and a stronger signal and more accurate data can be obtained. In addition, the probe inserted into the soil can directly propagate the electromagnetic waves to the deep layer of the soil, thereby realizing the deep detection of the internal structure and properties of the soil.

In some embodiments of the present application, before the step of analyzing and detecting the moisture content of the detected soil and predicting the condition of the shield cutter head forming mud cake according to the waveform curve, the following steps are also included:

When the waveform curve tends to be stable, the telescopic end of the telescopic motor 12 is controlled to retract, the probe 10 is pulled back to the initial position, and the probe 25 retracts toward the telescopic motor 12 through the opening until the telescopic amount of the telescopic motor 12 reaches the minimum telescopic amount.

As another embodiment D, this embodiment D proposes a more specific method of using a shield cutter head mud cake detection device based on the TDR principle on the basis of embodiment C.

When the waveform curve tends to be stable, the telescopic end of the telescopic motor 12 is controlled to contract, the probe 10 is pulled back to the initial position, and the probe 25 is retracted toward the soil retaining box 8 through the opening until the telescopic amount of the telescopic motor 12 reaches the minimum telescopic amount, and at the same time, the rubber ring 15 scrapes off the soil on the surface of the probe 25 and leaves it outside the soil retaining box 8. After the probe 10 is pulled back to the initial position, the conical head of the probe 25 is always exposed outside the opening, and the radial thickness of the rubber ring 15 increases, tightly wrapping the probe 25 and filling the gap between the probe 25 and the opening.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and/or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

Each patent, patent application, patent application disclosure, and other materials, such as articles, books, instructions, publications, documents, etc., cited in this application are hereby incorporated into this application in their entirety as a reference, except for application history documents that are inconsistent with or conflicting with the content of this application. It should be noted that if the description, definition, and/or use of terms in the attached materials of this application are inconsistent or conflicting with the content of this application, the description, definition, and/or use of terms in this application shall prevail.

Claims (10)

1. The utility model provides a shield constructs blade disc mud cake detection device which characterized in that includes:

The soil blocking box is characterized in that one side in the soil blocking box is fixedly provided with a telescopic motor, the other side is provided with an opening, the telescopic end of the telescopic motor is connected with a probe, one end of the probe, which is away from the telescopic motor, is provided with a plurality of probes, and the probes are aligned and matched with the opening;

The data sampling device and the data exciter are arranged outside the soil blocking box, the data sampling device is connected with the data exciter through a coaxial line, the data exciter is connected with a coaxial cable, the tail end of the coaxial cable is provided with a BNC connector, each probe is respectively connected with a connecting wire, the connecting wires extend to the outside of the soil blocking box and are connected with a data transmission line, and the other end of the data transmission line is connected with the BNC connector;

wherein, the probe can be along with flexible volume change of flexible end of flexible motor is in the soil retaining box outside removes.

2. The shield cutter head mud cake detection device according to claim 1, wherein the soil retaining box comprises a bottom plate and a cover plate, the bottom plate is arranged opposite to the cover plate, and the opening is formed in the cover plate.

3. The shield cutter head mud cake detection device according to claim 2, wherein the connecting wire extends to the outside of the soil retaining box through the bottom plate, and is electrically connected with the data exciter and the data sampler in sequence through the data transmission line.

4. The shield cutter head mud cake detection device according to claim 2, wherein the opening is embedded with a rubber ring, the rubber ring has an axial direction, and two sides of the rubber ring extend to two sides of the opening respectively along the axial direction and are fixed with the cover plate.

5. The shield cutter head mud cake detection device according to claim 2, wherein the telescopic motor is connected with a plane plate connecting piece, the plane plate connecting piece is fixed on the bottom plate through a hexagonal threaded connecting piece, and an electric wire of the telescopic motor penetrates through the bottom plate to extend to the outside of the soil retaining box and is connected with a telescopic motor power supply.

6. The shield cutter disc mud cake detection device according to claim 1, wherein the probe comprises a connecting plate, one side of the connecting plate is fixedly connected with the tail part of the probe, and two connectors which are oppositely arranged are arranged on the other side of the connecting plate; the telescopic motor is characterized in that a telescopic motor connector is arranged at the telescopic end of the telescopic motor, the telescopic motor connector extends to the position between the connectors, and two sides of the telescopic motor connector are connected with the connectors respectively.

7. The shield cutter head mud cake detection device according to claim 1, wherein the head of the probe is exposed from the opening when the amount of expansion of the expansion end of the expansion motor is a minimum.

8. The shield cutter disc mud cake detection apparatus of any one of claims 1 to 7, wherein the head of the probe is tapered.

9. A method for detecting mud cake of a shield cutter disc, which is applied to the device for detecting mud cake of a shield cutter disc according to any one of claims 1 to 8, and comprises the following steps:

Installing the shield cutter disc mud cake detection device on a cutter disc and starting the shield cutter disc mud cake detection device;

controlling the telescopic motor to push the probe to move towards the direction of the opening, and enabling the probe to move towards the direction deviating from the telescopic motor and to be inserted into the detection soil until the telescopic end of the telescopic motor reaches the maximum telescopic amount;

The data exciter is controlled to generate pulse electromagnetic waves and output the pulse electromagnetic waves through the probe, the obtained reflected signals are transmitted to the data sampler, and the data sampler generates waveform curves according to the reflected signals;

and analyzing and detecting the water content of the detection soil and predicting the condition of mud cake formation of the shield cutter head according to the waveform curve.

10. The method for detecting mud cake of shield cutter head according to claim 9, further comprising, before said step of analytically detecting the water content of the detected soil and predicting the mud cake of the shield cutter head based on the waveform profile:

When the waveform curve tends to be stable, the telescopic end of the telescopic motor is controlled to shrink, the probe is pulled back to the initial position, the probe retracts towards the soil retaining box through the opening, and the telescopic motor stretches out and draws back until the telescopic motor stretches out and draws back to the minimum telescopic amount.