JPS62178689A - Method and device for detecting face disintegration of shielding type excavator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method and an apparatus for detecting face collapse that occurs during excavation work using, for example, a shield excavator. This invention relates to a face collapse detection method for shield type excavation tickets that detects the shape of face collapse from this method, and improvements to the detection device.

(Conventional technology) Conventionally, there are sealed shield type tunnel excavators such as mud type, earth pressure type, and mud water pressurized type, but these i-machines are shielded by a skin plate on the outside, so it is difficult to excavate from the inside. It is impossible to know the state of the face of time. That is, even if the tunnel face collapses, this tunnel excavator continues to move forward, leaving a cavity 1 as shown in FIG. 9, which may cause the ground to cave in at a later date. In the figure, 2 is the ground surface, 3
4 is the ground, and 4 is the segment 1- which makes the annular part formed after the face function as a clay pipe.

Therefore, a face collapse detection device that can detect the state of face collapse has been developed as a one-size-fits-all material for preventing the above-mentioned ground collapse. One of them is a detection device using an ultrasonic method (see Utility Model Application Publication No. 58-1.40296 and specification 41 drawing attached to the application), and the other is a cutter located at the front. There is a stylus-type detection device that measures the state of face collapse by installing a measuring needle near the face and bringing the measuring needle into contact with the face surface when excavation is stopped.

However, in the case of the ultrasonic method, since ultrasonic waves are attenuated by muddy water, measurement accuracy will inevitably deteriorate if left as is, making it difficult to put it into practical use. Therefore, a fresh water displacement type ultrasonic method is being considered as an alternative to this. This method uses a submersible pump to inject fresh water into Gen 1, replacing muddy water with fresh water and forming an ultrasonic path. Face collapse can be determined from the time between the probe and the reflected echo that passes through the soaked water and is reflected back from the ground. However, this method is limited to the weight of muddy water, and it is difficult to maintain a clean water atmosphere without causing landslides.
There are practical problems.

On the other hand, the stylus type is capable of measuring only when excavation is stopped, cannot perform continuous measurements, and is insufficient as a detection device for face collapse.

Therefore, the present inventors energized the electrical double layer consisting of muddy water and earth using a pair of energizing currents attached to the surface of the skin plate as described in Japanese Patent Application No. 160,620/1983. A potential distribution is formed, and from this potential distribution and the applied current, the apparent resistivity as seen from the muddy water side is determined. From the change in the above resistivity, the presence of cavities due to face collapse can be determined by A detection method and a detection device for detecting the change have been proposed. Figures 10 and 11
The figures are a configuration diagram and a schematic diagram of the above-mentioned detection device using the four-electrode method. In these figures, 5 is muddy water, 6 is a cutter face, 7 is a skin plate, 8 is an insulating plate, 9a,
9b is a pair of current-carrying electrodes, 10a and 10b are a pair of voltage measurement electrodes, 11 is a constant current source, 12 is a voltage measurement section, and 13 is an output display section. Voltage measuring electrodes 10a and 10b are arranged, and the distance between these electrodes is equidistant 111a. In addition, d is the mud thickness, ρ1 is the mud specific resistance, and ρ2 is the ground (
Clay) indicates specific resistance. That is, this four-electrode detection device is
A constant current is applied to the current-carrying electrodes 9a and 9b to energize the electrical double layer consisting of muddy water and other layers. The thickness of muddy water is detected from the measured voltage as shown in .

[Problems to be Solved by the Invention] However, in the case of detecting a collapsed shape using an electrode system as described above, for example, in the case of a collapsed shape as shown in FIG. 13, the collapse width as shown in FIG. There is a problem in that the measured voltage changes due to changes in . Therefore, although the detection device shown in FIG. 10 is capable of detecting collapse, it is not possible to accurately determine the shape of collapse.

The present invention has been made in view of the above-mentioned circumstances, and is a shield-type excavation face IO that can accurately detect the shape of face collapse online without causing ground collapse! @The purpose is to provide a detection method.

Another object of the present invention is to provide a face collapse detection device for a shield type excavator that can detect the shape of a face collapse with a simple configuration without providing any special protrusions on the surface of the excavator.

[Means for Solving the Problems] Therefore, according to the method of the present invention, a set of four electrodes consisting of a current-carrying electrode and a voltage-measuring electrode is arranged on an insulating part whose surface area is substantially the same as the surface of the skin plate, and the current is connected at intervals. Two sets are set up with different voltages, and each phase is selected to energize the electrical double layer consisting of muddy water and rock, and the collapse shape of the face can be detected from changes in the potential distribution. .

Further, according to another device of the present invention, two sets of four electrodes each consisting of a current-carrying electrode and a voltage-measuring electrode are installed at different electrode intervals on an insulating part having substantially the same surface area as the skin plate of the excavated amount. an electrode channel switching means for selecting an electrode for each set of electrodes, and a predetermined signal is given to the energization type selected by the electrode channel switching means to prevent muddy water and ground from being removed. a power supply unit that energizes the electrical double layer, and an arithmetic processing means for determining a face collapse shape using a change signal of the potential distribution obtained from the lightning rod 1 regular electrode after energization by the power supply unit. It is something.

[Effect]

Therefore, by using the method of the present invention as described above, each set of electrodes with different electrode spacing is selected and energized, and the collapsed shape of the face can be obtained using the signal obtained from the voltage measuring electrodes. If you do this, you will break the IF! It is possible to obtain the desired signals as a measurement system with sensitivity in both the width and collapse depth directions, and it is possible to eliminate ground collapse and accurately detect the face collapse shape online.

In addition, by using another device of the invention, since the electrodes are provided on almost the same surface as the skin plate surface, there are no special protrusions on the excavated surface, and the electrode channel switching means allows the electrode spacing of 2911 to be different. Since the electrode group is switched to obtain a desired signal, the collapsed shape of the face can be detected with a simple configuration.

〔Example〕

An embodiment of the method of the present invention will be described below with reference to FIGS. 1 to 3.
This will be explained with reference to the figures. That is, the method of the present invention employs a four-electrode method in which the mud ring is electrically measured by focusing on the difference in resistivity between the mud and the ground. A1 has one set of 4-electron FF120a, 20b,
21a, 21b are arranged, and a set of four electrodes 22a, 22b, 23 are arranged outside these electrodes with a wide electrode interval a2.
a.

23b are arranged, each measuring voltage Vl.

■Detect the collapsed shape from 2. 24.25 is a constant current source,
26 is muddy water, 27 is ground, 28 is skin plate (third
Figure) is shown.

However, in the above electrode arrangement configuration, the narrow Il
When using a four-electrode method consisting of electrode groups 20a, 20b, 21a, and 21b with i spacing a1, the apparent resistivity as seen from the electrodes 20a and 20b is ρ.

Then, V=(I ρe ) / (2π a 1 −)
-- can be determined from the equation (1). However, in the above equation, I is the applied current, ■ is the measured voltage, ρl is the specific resistance of the muddy water, ρ2 is the specific resistance of the other mountain, d is the muddy water ring, and al is the electrode spacing.

The above apparent appearance is due to the fact that the electrode spacing a1 is larger than the muddy water 1d, as is clear from Figure 2, which shows the relationship between the resistivity ρ above and the ratio d/a1 between the muddy water ring and the electrode spacing. When it is small, the resistivity ρ6 hardly changes by /υ. Therefore, although a measurement system with a narrow electric bridge spacing a1 can detect the collapse width A-B in the shape as shown in Fig. 13,
Shows no sensitivity to depth. Therefore, the method of the present invention includes a measurement system that is sensitive only to the width of the collapse and a measurement system that is sensitive to the depth direction, and has a narrow electrode spacing al for the collapse shape shown in FIG. Electrode groups 20a, 20
The collapse width A-B is determined using a measurement system consisting of electrodes 22a, 22b, 2 with a wide electrode spacing a2.
The collapsed shape is determined by converting the measured voltage measured by the measuring system consisting of 3a and 23b into the groove depth d from the relationship between the collapsed width and the dV curve shown in FIG. 14 mentioned above.

Therefore, according to the collapse detection method of the above embodiment,
By arranging four electrodes with narrow electrode spacing to be sensitive to the collapse width, and by arranging four electrodes with wide electrode spacing to have sensitivity in the direction of collapse depth, both of these phases can be By using the output from the electrode, the collapse shape can be determined with high accuracy. Moreover, by alternately switching between these two sets of electric shocks and excavating, the shape of the collapse can be determined continuously and online.

Next, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 4, this device is provided with a cutter face 31 on the front side, and a skin plate on the back side of the cutter face 31 that functions as an outer body of the device and is formed in an annular shape with the same diameter as the cutter face 31. 28 are provided. This skin plate 28 has one side cut out, and an insulating plate 32 having substantially the same surface as the skin plate 28 is fitted in this part. As shown in FIG. 1, this insulating plate 32 has four collapse width detection electrodes 20a, 20b, 21a, 2 with narrow electrode spacing al.
11) is embedded, and four collapse depth detection molds [x22a, 22
b, 23a, and 23b are embedded. Behind these electrodes, electrodes 20a, 20b, 22a, 22b correspond to current-carrying electrodes, and the batteries JM21a, 21b, 23a, 23
b corresponds to the voltage training claw pole. In FIG.
34 is a constant current source that supplies a constant current to b, and 34 is a collapse width detection type tffi 20a, 20b, 21a, 21b and collapse depth detection electrodes 22a, 22b, 23a.

23b, and can be represented, for example, in a schematic configuration as shown in FIG.
The switching may be performed automatically using a clock or the like. 35 is a voltage measuring unit that converts the signal measured by the voltage measuring electrode into a measured voltage proportional to the voltage and outputs it in two channels; 36 is a calculation unit that performs predetermined calculation processing using the measured voltage from the voltage measuring unit 35; The processing section 37 is an output display section that outputs the calculation results.

Next, the operation of the apparatus configured as above will be explained.

Now, during shield excavation, Iff width b = 00111
It is assumed that a collapsed shape of a triangular groove having a collapse depth d-, 200I is detected. The measurement conditions are: specific resistance ρ1-10Ωm of the muddy water 26, specific resistance ρ2 of the earth 27.
=200Ωm, electrode spacing al for detecting collapse width = 20a-2
1a=218-21b=2 l b-20b=20mm
, Collapse depth detection electrode spacing a2=22a-23a=23
It is assumed that a-23b=23b-22b-100 mm, and a current of 10 mA and 20 Hz is supplied from the constant current source 33 to the current-carrying electrode side. Further, the normal mud thickness d when there is no collapse is 20InIIl.

Therefore, under the above measurement conditions, the constant current source 3
3 to each energized electrode (20a, 2'Ob) with different electrode spacing via the electrode channel changeover switch 34,
(22a, 22b), a constant current is applied to the electrical double layer consisting of muddy water and the ground. This energization method is based on one constant current source 33 and a changeover switch 34 that is automatically switched by a clock, for example.
b (chl) and energizing machine 1M22a, 22b (ch
2),! : energize alternately. The reason for this is to prevent potential distributions formed underground from interfering with each other. When the current is applied as described above, the TIFi measurement electrodes (21a, 21b), (23
Since a potential is generated between 21a and 23b), this is measured by the voltage measuring section 35, and the voltage between 21a and 21b is set as chl.
The voltage between 38 and 23b is output as ch2. During shield excavation, the measurement electrode system also moves simultaneously with the shield machine, and a measurement voltage as shown in FIG. 6 is obtained for the moving distance.

The measured voltage thus measured is sent to the subsequent arithmetic processing section 36. This arithmetic processing unit 36 detects the collapse shoulder from the point where the Chl output, that is, the output obtained by the measurement system with the electrode spacing a1, changes.
The width of the collapse is calculated and a value of b=300 mm is obtained.

In addition, the collapse depth is detected using the output of ch2, that is, the output obtained by 1q from the measurement system with the electrode spacing a2, but as shown in Figure 7, the measured voltage value with respect to the collapse depth is determined by the collapse width. The rate of change is different, and the rate of change is also different. Therefore, the performance division 36 prepares in advance the d-V curve shown in FIG. 7 with the collapse width as a parameter, and
Based on the information obtained from l b = 300 mm d
-V [Select ltl line.

Furthermore, this calculation model unit 36 converts the output voltage value of ch2 into muddy water depth based on the dV curve selected in the above step. Here, the value converted to the muddy water depth is displayed on the output display section 37 as a value as shown in FIG. 8, for example. Therefore, during shield excavation, such display values are monitored to detect early face collapse and to detect the collapse shape.

Therefore, according to the configuration of the embodiment as described above, two sets of four electrodes with different electrode intervals are embedded in the insulating plate 32 having the same surface as the skin plate t~28, and the electrodes in each set are alternately switched. By using these measurement voltages, the collapse width and collapse depth are determined by 1q to determine the collapse shape, so the collapse shape can be determined with high accuracy with a very simple configuration.

In the above example, the electrode spacing was 81=20 mm, a2
= 100 mm, but it is not limited to this, and it is possible to set the current by changing the measurement span by arbitrarily changing the distance.Also, the current value (10 mA, 20 H
Although the current value is set to z, it is also possible to increase the current value to a higher value to improve the resolution, and the same applies to the frequency.

However, the present invention can be modified in various ways without deviating from its essence.

〔Effect of the invention〕

As detailed above, according to the method of the present invention, the measured 7R pressure is obtained by alternately switching two sets of 4-electrode groups with different electrode intervals, so that the measurement voltage is sensitive to the collapse width and collapse depth. It is possible to determine the collapse shape using , and it can also be detected continuously and accurately online, making it possible to perform cavity repair at an early stage and prevent collapse accidents.

Further, according to the device of the present invention, four electrodes are embedded in two phases in the insulating plate on the skin plate surface, and each set of electrodes is alternately switched with a switch to obtain the measurement voltage, so that the protrusion is provided. It is possible to provide a collapse detection device for a shield type excavator that can accurately detect the collapse shape by simple I-growth without any problems.

[Brief explanation of drawings]

Figures 1 to 3 are shown to explain one embodiment of the method of the present invention. Figure 1 is a schematic diagram showing the electrode arrangement and measurement conditions, and Figure 2 is a diagram showing the thickness of muddy water and the electrode spacing. 3 is a schematic diagram of the collapsed shape, and FIGS. 4 to 8 are shown to explain an embodiment of the device of the present invention. Fig. 4 is a block diagram of the @ position of the present invention, Fig. 5 is a switching block diagram of the 0 channel changeover switch in Fig. 4, Fig. 6 is a characteristic diagram of the 1j constant voltage with respect to the moving distance, and Fig. 7 The figure shows the relationship between collapse depth and measurement voltage, Figure 8 shows the collapse shape display state, Figures 9 to 14 are shown to explain conventional detection devices, and Figure 9 shows the excavator. Fig. 10 is a configuration diagram of a conventional device using the 4-power method, and Fig. 11 is a schematic diagram explaining the state of measuring the collapse shape using the 4-power method. , Fig. 12 is a diagram showing the relationship between the thickness of muddy water and the measured voltage, Fig. 13 is a diagram showing the collapsed shape formed in the triangular groove, and Fig. 14 is a diagram showing the relationship between the triangular groove and the measured voltage. 20a, 20b. , 21 a, 21 b - Electrode for detecting collapse width, 22 a, 22 b, 23 a, 23 b - Electrode for detecting collapse depth, 24.25.33 - Constant current source, 26
... Muddy water, 27 ... Earth, 28 ... Skin plate, 31 ... Cutter face, 32 ... Insulating plate, 3
4... Electrode channel changeover switch, 35... Voltage measuring section, 36... Calibration processing section, 37... Output display section. Applicant's representative Patent attorney Takehiko Suzue Figure 3 0.1110 ) Amagagi [l/] Polar spacing Figure 4 Figure 5 Travel distance Figure 6 Collapse depth d (mm) Figure 7 Travel distance (mm) Figure 7 Figure 8, -4 Figure 10 Figure 12 Collapse depth d (mm) Figure 14

Claims (2)

[Claims] (1) Two sets of four electrodes consisting of a current-carrying electrode and a voltage-measuring electrode are provided on the insulating part, which has a surface that is almost the same as the skin plate surface, with different spacing between the electrodes, and each set is selected to remove the muddy water. A method for detecting collapse of a face of a shield type excavator, characterized in that the shape of collapse of the face of the face is detected from changes in the electric potential distribution by energizing an electrical double layer made of ground. (2) In a shield-type excavator face collapse detection device that energizes an electrical double layer consisting of muddy water and ground and detects face collapse from changes in the electric potential distribution, the face collapse detection device for a shield type excavator is provided at a surface that is approximately flush with the skin plate of the excavator. an electrode arrangement means in which two sets of four electrodes each consisting of a current-carrying electrode and a voltage-measuring electrode are installed on the same insulating part with different electrode spacing; and electrode channel switching for selecting electrodes for each of these sets. means, a power supply unit for supplying a predetermined signal to the energized electrode selected by the electrode channel switching means, and a face collapse shape using the signal output from the voltage measuring electrode after energization by the power supply unit. What is claimed is: 1. A face collapse detection device for a shield type excavator, characterized in that it is equipped with a calculation processing means as required.