JP2002139395A - Water-leakage position detection device and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve accuracy of detection of a water-leakage position through correction by extracting only the current flowing in leaked water and grasp the characteristics of current flowing through a protective layer. SOLUTION: A sealing work construction is constituted by an insulating sealing work 2, provided on a depression of the ground and the protective layer 3 through which the current is carried provided on the sealing work. A planar electrode 12 is disposed on a front surface or a reverse surface of the sealing work, and plural point electrodes are disposed on a side opposite to the planar electrode. Circular electrodes 13a and 13b for surrounding around the plural point electrodes or the planar electrode are located near a part where the protective layer is brought into contact with the ground. One of the point electrodes is selected from among the plural point electrodes and is connected with one end of a power supply, and all of the point electrodes, except the selected point electrode, the planar electrode and the circular electrode are connected with the other end of the power supply. A current, flowing between the selected point electrode, the planar electrode and the circular electrode, is measured, and a current component flowing through the protective layer is corrected from the measured current value of the planar electrode with the usage of the measured current value of the circular electrode. The water-leakage position of the sealing work construction is detected from the corrected current value and from the position of the selected point electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reservoir, a waterway, or a managed municipal waste which is artificially constructed by laying a water shield made of an electrically insulating material such as synthetic resin or synthetic rubber. TECHNICAL FIELD The present invention relates to a water leakage occurrence position detecting device and method for detecting a water leakage occurrence position generated in a water impervious structure of a water impervious structure, such as a final disposal site and a managed industrial waste final disposal site.

[0002]

2. Description of the Related Art As shown in FIG. 10, a water-blocking structure 1 such as a reservoir, a waterway, a managed general waste final disposal site and a managed industrial waste final disposal site is made of synthetic resin or synthetic rubber. A water-blocking work (for example, a water-blocking sheet) 2 made of a material having electrical insulation property is laid and artificially made.

[0003] When a break such as a crack occurs in the water shield 2, the water shield structure 1 leaks from the damaged portion L. For example, in the case of a managed general waste final disposal site, if the impermeable structure is left in a damaged state, the waste H itself or the waste H
As a result, the contaminated liquid leaks and contaminates the neighborhood, or pollutes the groundwater, causing pollution problems. Therefore, it is necessary to repair the damaged portion of the water-blocking structure 1 using the water-blocking work 2 by detecting the occurrence and location of the water leakage (or breakage of the water-blocking work) L at an early stage.

[0004] In order to detect the position where the water leakage occurs in the water-blocking structure 1, a detection method as shown in FIG. 9 is employed. In this detection method, a plurality of point electrodes A _{1 to} H ₈ are arranged at predetermined intervals inside a water impervious structure 1 on which a water impervious work 2 is laid, and a back side (ground side, FIG. An electrode arrangement configuration in which a surface electrode 12 such as a non-woven fabric on which an aluminum foil or the like is attached is disposed. This point electrodes A ₁ to H ₈ is connected to the terminal to one of the AC power supply 4 via an electrode switching unit 15a and the ammeter 5a. The surface electrode 12 is connected to the AC power supply 1.
2 is connected to the other terminal. In addition, the electrode switch 15
“a” selects the point electrodes A _{1 to} H ₈ one by one and connects them to one terminal of the AC power supply 4 via the ammeter 5a.

In such an electrode arrangement, the point electrodes A _{1 to} H ₈ inside the water shield structure 1 are selected one by one via the electrode switch 15 a, and the point electrodes A _{1 to} H ₈ are selected between the selected point electrode and the surface electrode 12. An AC voltage is applied, and the current flowing during this time is detected by the ammeter 5a. Then, a water leak occurrence position is detected from a comparison of the detected currents at each of the selected point electrodes A _{1 to} H ₈ .

[0006]

By the way, in order to prevent ultraviolet ray deterioration and thermal deterioration of the water shielding work and to make a road for carrying waste, the protective layer 3 made of a soil material or concrete is provided with a water shielding work. 2 are provided so as to cover the entirety. Since the protective layer 3 is not an electrical insulator, if electrodes are provided above and below the water shield 2, the upper and lower electrodes between the upper and lower water shields are connected to each other via the protective layer 3 (short circuit). An electric circuit is formed (see FIG. 10).

When the short-circuited electric path is formed, the current value measured by the ammeter 5a is a mixture of the current through the water leak L and the current through the protection layer 3, which are to be detected. In particular, since the current flowing through the protective layer 3 may be larger than the current flowing through the water leak L, it is difficult to distinguish between a short-circuit circuit and a water leak L, thereby improving the accuracy of detecting a water leak occurrence position. Was an obstacle in

In view of the above, the present invention has been made in view of the above-mentioned problems. By grasping the characteristics of the current flowing through the protective layer, a correction for extracting only the current flowing in the water leakage is performed, and the occurrence of the water leakage is corrected. A technical problem is to provide a water leakage occurrence position detecting device and a method thereof that improve the accuracy of position detection.

[0009]

Means for Solving the Problems In order to achieve the above object, a water leakage occurrence position detecting apparatus and method according to the present invention employs the following means. In other words, the water leakage occurrence detecting device according to claim 1 is a water leakage shielding device in which a water shielding work of an electrical insulator is laid in a depression formed in the ground and a protective layer for conducting electricity is provided in a layer on the water shielding work. Engineering structure, a surface electrode installed on either side of the water shield, a plurality of point electrodes installed on the opposite side of the surface electrode, and in the vicinity of a portion where the protective layer contacts the ground, A plurality of point electrodes or an annular electrode disposed around the periphery of the surface electrode, and one of the plurality of point electrodes selected and connected to one end of a power source, and all points except the selected point electrode An electrode, selective connection means for connecting the plane electrode and the annular electrode to the other end of the power supply, and current measuring means for measuring a current flowing between the selected point electrode and the plane electrode and the annular electrode,
Correction means for correcting a current component flowing through the protective layer from the measured current value of the surface electrode using the measured current value of the annular electrode, and the corrected current value and the selected point electrode. It is characterized by detecting a water leakage position of the impermeable structure from a position.

In the water leakage occurrence position detecting device according to a second aspect of the present invention, a plurality of the annular electrodes are provided, and at least one of the annular electrodes is connected to the other end of the power supply by the selective connection means bypassing the current measuring means. It is configured to connect to.
Therefore, among the plurality of annular electrodes, the annular electrode connected to the other end of the power supply via the current measuring means is a correction-only electrode,
The ring-shaped electrode connected directly to the other end of the power supply bypassing the current measuring means is a dedicated electrode for electric field control.

According to the first and second aspects of the present invention, one point electrode (applied electrode) connected to one end (applied terminal) of the power supply by the selective connection means, and all points except this applied electrode Between the point electrode, the surface electrode, and the ring electrode (the electrode dedicated to correction and the electrode dedicated to electric field control), (1) applied electrode → ground →
Point electrodes other than the applied electrodes and electrodes dedicated to electric field control installed on the ground side → the other end of the power supply. (2) Applied electrode → protective layer → electrode for correction → current measuring means → other end of power supply. (3) Applying electrode → water leakage → surface electrode → current measuring means → other end of power supply. (4) A circuit is formed from the applied electrode → the protective layer (or the ground) → the surface electrode → the current measuring means → the other end of the power supply. The current value detected from the current measuring means connected to the surface electrode includes the current flowing through the water leakage (circuit (3)) and the current flowing through the protective layer (circuit (4)). Have been. On the other hand, the value of the current flowing through the circuit (2) is the value of the current flowing through the protective layer and the correction electrode, but is near the portion where the correction electrode is in contact with the protective layer and the ground around the impermeable structure. Are located in
Since the correction electrode is located at a position that traverses the path that short-circuits the top and bottom of the water shield, the tendency of the measured current value is considered to be almost the same as the tendency of the current flowing through the protective layer. Therefore, the characteristic of the current flowing through the protective layer is obtained from the current value flowing through the correction electrode, and the measured current value of the surface electrode mixed with the current flowing through the protective layer passes through the protective layer. To remove the current component flowing through the filter and to extract only the current component related to water leakage.

In addition, all the point electrodes, surface electrodes and electrodes dedicated to electric field control (that is, electric fields above and below the water shield) other than the applied electrode are connected to the other end of the power source that is not the application side by the selective connection means. At the same potential. In addition, the surface electrode and the ring electrode provided on the opposite side of the application electrode across the water shield have polarities opposite to those of the application electrode, and the ring electrode is provided in a protective layer (or ground) serving as a short-circuit path. And the correction electrode connected to the current measuring means is closer to the applied electrode than the surface electrode, so that the current flowing to the surface electrode via the protective layer (or the ground) can be reduced, and as a result, protection can be achieved. It acts to reduce the current flowing through the short circuit path of the layer.

[0013] Examples of the water shielding work include a synthetic resin and a synthetic rubber which are electrically insulating materials. Examples of the protective layer used in the managed waste final disposal site include a case where a nonwoven fabric (light-shielding mat) of polyester or polypropylene is laid, or a case where a soil material or concrete is laid.

Further, the water leak occurrence position detecting device according to claim 3 is configured such that the current measuring means has a phase detection circuit for extracting a current component having the same wavelength and the same phase as the applied voltage of the power supply.

According to the third aspect of the present invention, only the current component having the same wavelength and the same phase as the applied voltage of the power supply is extracted from the measured current value detected by the current measuring means, so that the natural current and the natural current can be extracted from the measured current value. Harmonic noise can be removed. This improves the accuracy of the measured current value,
The accuracy of detecting the location where a water leak occurs is improved.

Further, in the method for detecting a water leakage occurrence position according to a fourth aspect, a water barrier of an electrical insulator is laid in a depression formed in the ground, and a protective layer for conducting electricity is provided in a layer on the water barrier. And a water impervious structure, a surface electrode is installed on either side of the water impervious structure, a plurality of point electrodes are installed on the opposite side of the surface electrode, and a portion where the protective layer comes into contact with the ground. A plurality of point electrodes or an annular electrode surrounding the surface electrode is disposed, one of the plurality of point electrodes is selected and connected to one end of a power supply, and all except for the selected point electrode. The point electrode, the plane electrode and the annular electrode are connected to the other end of the power source, and a current flowing between the selected point electrode, the plane electrode and the annular electrode is measured, and the measured current of the annular electrode is measured. Protection from the current value measured at the surface electrode using the value It corrects the current component flowing through the, and detecting the water leakage position of the water-impervious Engineering structure from the position of the corrected current value and the selected points electrode.

According to the fourth aspect of the present invention, by arranging the annular electrode, the current passing through the surface electrode can be measured under the condition that the electric potential inside and outside the impermeable structure becomes the same electric potential. Then, since the inside and outside of the measurement target (water shielding work) are controlled to the same potential except for around the application electrode, the current flowing through the protective layer can be reduced. In addition, since the characteristics of the current flowing through the annular electrode are similar to the characteristics of the current flowing through the protective layer among the characteristics of the current measured by the current measuring electrode (plane electrode), the characteristics of the current flowing through the protective layer pass through the protective layer. Current flowing therethrough can be corrected. That is, from the current flowing through the annular electrode provided in the protective layer around the current measuring electrode (plane electrode) and the measured value of the current passing through the previous current measuring electrode (plane electrode),
The current flowing through the protective layer can be corrected.

As described above, in the present invention, the measurement target for detecting the position where the water leak has occurred is a current component, but the measurement target of the present invention is not only the current value but also the electric resistance value obtained from the measured current value and the applied voltage. You may. The power supply which is a component of the present invention may be a two-phase AC power supply or an alternating DC power supply.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a water leakage occurrence position detecting device according to an embodiment of the present invention will be described in detail with reference to FIGS. In addition, the water leak occurrence position detecting device according to the embodiment is installed in the water shielding structure 1. In addition, the case where the impermeable structure 1 is a managed waste final disposal site will be described.

As shown in FIG. 1, a water-blocking structure 1 has a water-blocking structure 2 laid in a depression 1a and a protective layer 3 laminated on a slope portion of the water-blocking structure 2 so as to cover the entire water-blocking structure 2. is there. And
The water shield 2 is formed of an electrically insulating synthetic resin. The protective layer 3 is formed of a concrete material that is not an electrical insulator, and the upper surface and the lower surface of the water shield 2 laid on the water shield structure 1 are electrically short-circuited via the protective layer 3. The circuit can be formed.

The protective layer 3 used in the final disposal site for managed waste may be laid with a non-woven fabric (light-shielding mat) of polyester or polypropylene, or with a soil material or concrete. Compared with fibers, soil materials and concrete are more suitable for preventing ultraviolet light deterioration and heat deterioration of the water shielding work, and are known to be materials excellent in durability. Concrete is a material with much higher durability for roads carrying waste. Therefore, in this embodiment, description will be made assuming that the protective layer 3 made of concrete is laid.

The water leakage occurrence position detecting device has a surface electrode 12 (see FIG. 2 (a)) in which linear electrodes are arranged in a grid pattern inside a water impervious structure 1 on which a water impervious work 2 is laid. A plurality of point electrodes T _{a1 to} T _j10 (FIG. 2)
(See (b)) at predetermined intervals, and further, annular electrodes (a correction electrode 13a and an electric field control electrode 13b; see FIG. 1) on the upper and lower sides of the water shield 2 so as to surround the entire water shield 2. Is used.

The surface electrode 12 is connected to one side 4a of the AC power supply 4 via a current measuring device 5. On the other hand, it is connected to one 4a or the other 4b of the AC power supply 4 via the respective point electrodes point electrode T _a1 through T _j10 electrode switching device 15.

When one of the point electrodes T _{a1 to} T _j10 (point electrode T _{d4 in} FIG. 1) is selected, the electrode switching device 15 has a function of connecting all the other point electrodes in common. That is, the point in the electrode T _a1 through T _j10, the output side while the fourth electrode switching device 15 a point electrodes T _d4 AC power source 4, which is selected by
b, and all the other point electrodes are connected to an AC power source 4 in common.
Is directly connected to one side 4a.

Further, the correction electrode 13a and the electric field control electrode 13b are disposed above or below the water shield 2 and are annularly arranged in the protective layer 3 or the ground. The correction electrode 13a is connected to one side 4a of the AC power supply 4 via the current measuring device 5. The electric field control electrode 13b is connected directly to one side 4a of the AC power supply 4 bypassing the current measuring device 5.

As shown in FIG. 3, the AC power supply 4 has a power amplification circuit 41 and an oscillation circuit 42, and the oscillation circuit 42 is connected to the power amplification circuit 41. The oscillation circuit 42 outputs a signal waveform, and the power amplification circuit 41 power-amplifies the signal waveform generated by the oscillation circuit 42.

The AC power supply 4 is connected to the point electrodes _{Ta1 to} Ta1.
_A voltage is applied to a circuit formed by the selective connection of the electrode switching device 15 between _j10 and the plane electrode 12.

As a result, the following circuit is formed.
Note that Saegimizuko 2, it is assumed that the leakage L occurs at the position of the point electrodes T _D4. That is, (1) the electrode switching device 15
→ Point electrode T _d4 → ground → point electrode other than point electrode T _d4 and annular electric field control electrode 13b installed on the ground side → one 4a of AC power supply 4. (2) Electrode switching device 15 → point electrode T _d4 → protective layer 3 → correction electrode 13 a → current measuring device 5 → one of AC power supply 4
a. (3) Electrode switching device 15 → point electrode T _d4 → water leakage L → surface electrode 1
2 → current measuring device 5 → one 4a of AC power supply 4. (4) A circuit of the electrode switching device 15 → point electrode T _d4 → protective layer 3 (or ground) → surface electrode 12 → current measuring device 5 → one of the AC power supply 4a 4a is formed.

According to the circuits (1) to (4), one point electrode (for example, the point electrode T _d4 ) selected by the electrode switching device 15 and all the point electrodes except the point electrode T _d4 are selected. Since the voltage of the AC power supply 4 is applied between the correction electrode 13a and the electric field control electrode 13b, all the point electrodes, the surface electrode 12, and the correction electrode except the point electrode T _d4 (applied electrode) are applied. When the electrode 13a and the electric field control exclusive electrode 13b are connected to the other side 4a which is not the application side, the electric potential is controlled to be the same. Therefore, the water leakage occurrence position detecting device is configured so that the circuits (1) to (4) are formed, so that the electric field above and below the water shield 2 is controlled to have the same electric potential.

That is, the electrode arrangement shown in FIG. 1 in which electrodes for controlling voltage application and potential (all point electrodes except the applied electrode and the electrode 13 b dedicated to electric field control) are installed on the ground side of the water shield structure 1. As can be seen, the annular electric field control electrode 13b controls the electric field above and below the water shield 2 where the protective layer 3 such as concrete connecting the inside and the outside of the water shield structure 1 comes into contact with the ground, to the same potential. When comparing the thickness of the annular electrode (the correction electrode 13a and the electric field control electrode 13b) with the cross-sectional area of the protective layer 3, the cross-sectional area of the protective layer 3 is large. Since it is difficult to control the flowing current, it is preferable that the number of ring electrodes is more than one.

Also, based on the electrode arrangement in FIG. 1, the upper and lower electric potentials of the water shield 2 are controlled by applying a selected point electrode (for example, a point electrode T _d4 ) to one of the AC power supplies 4 connected to the plane electrode 12. This is performed by connecting all the electrodes on the back surface side of the water shield 2 excluding only those. Then, the current measurement is performed on the surface electrode 12 in the water shield structure 1 and the correction electrode 13a on the upper side of the water shield structure 2. In this embodiment, the point electrodes _Ta1 to _Ta1 to
There is a point that the potential above and below the water shield 2 is positively controlled by T _j10, and it is more advantageous that the point electrode has a wider area than a _simple metal plate.

As shown in FIG. 4, the point electrode is formed by molding a bare copper wire into a square frame (reference numeral 14 in FIG. 4A).
a) or a bare copper wire formed into a spiral shape (Fig. 4
Reference numeral 14b) of (b) can be exemplified. The same effect can be expected if the point electrode is not only rectangular but also circular.

Further, the circuit (1) to (4) According to the surface electrode 12 disposed opposite the application electrode T _d4 across the Saegimizuko 2,
The correction electrode 13a and the electric field control electrode 13b have opposite polarities to the application electrode _Td4.
a and the electric field control exclusive electrode 13b are provided in the protective layer 3 (or the ground) serving as a short-circuit path, and the correction exclusive electrode 13a is closer to the application electrode T _d4 than the plane electrode 12, so that the protective layer 3 ( Or ground), the current flowing to the surface electrode 12 can be reduced.
To reduce the current flowing through the short-circuit path.

From the above, using the circuits (1) to (4), the protective layer 3
By grasping the characteristics of the current flowing through the filter, it is possible to perform a correction for extracting only the current component flowing in the water leakage.

By the way, of the circuits (1) to (4), the circuits from which the current is detected are (2) to (4), which are detected by the current measuring device 5.

As shown in FIG. 3, the current measuring device 5 includes a current detecting circuit 16, a phase detecting circuit 17, an A / D converter 18, and a computer 19, and the current detecting circuit 16 includes the phase detecting circuits 17 and It is connected to a computer 19 via a / D converter 18. The phase detection circuit 17 extracts a current component having the same wavelength and the same phase as the voltage applied to the power amplification circuit 41 from the detected current value. In other words, the phase detection circuit 17 removes a component having a phase different from the voltage applied to the power amplification circuit 41 (for example, a current component flowing through the water shield 2) from the detected current value. Therefore, in the phase detection output, only the current having the same wavelength and the same phase as the voltage applied to the power amplification circuit 41 is converted into a digital signal by the A / D converter 18 and supplied to the computer 19.

The computer 19 includes a ROM (Read Only Memory), RA connected to each other by a bidirectional bus.
M (random access memory), CPU (central processing unit), input port, output port. The input port of the computer 19 is connected to the current detection circuit 16 via the A / D converter 18 and the phase detection circuit 17, and receives an output signal (measured current value). The output port of the computer 19 is connected to the electrode switching device 15 (not shown) and outputs a command for switching the point electrode to the electrode switching device 15. The command for switching the point electrodes is executed based on a selective connection procedure described later (selective connection means). Furthermore,
The output port of the computer 19 is connected to, for example, a CRT device (not shown) and outputs a display command (image data) to the CRT device.

The ROM stores a program for detecting a position where a water leak has occurred and a program for a selective connection procedure.
The CPU reads these programs and performs processing. The selective connection procedure is as follows. In the electrode switching device 15, the terminals connected to the current detection circuit 16 are connected to the point electrodes _{Ta1 to} T
_j10 (see FIG. 2B) is a procedure for sequentially switching 100 types of procedures for connecting one by one. Then, the CPU reads the first (i = 1; for example, the point electrode T _a1 ) to the 100th (i = 100; for example, the point electrode T _j10 ) from the ROM and outputs a command to switch the electrode switching device 15.
Then, an AC voltage is applied to an arbitrary point electrode for each command order, and the position of the point electrode is selected.

Next, the water leak occurrence position detection processing of the present invention by the computer 19 will be described with reference to the flowchart of FIG.
The computer 19 sets “i = 1” (step 10
1) Switching of the electrode switching device 15 is performed according to the selective connection procedure stored in the ROM, and a point electrode (position) is selected (step 102). That is, the electrode switching device 15 connects the point electrode _Ta1 and the other 4b of the AC power supply 4 so that "i" becomes the first combination (i = 1; the point electrode _Ta1 ),
The other point power supply is connected to the other side 4b of the AC power supply 4, an AC voltage is applied between the one side 4a and the other side 4b of the AC power supply 4, and the positions of these point electrodes are selected. The correction electrode 13a and the plane electrode 12 are connected to one side 4a of the AC power supply 4 via the current measuring device 5, and the electric field control electrode 13b is directly connected to one side 4a of the AC power supply 4.

At this time, (1)
One 4a of the electrode switching device 15 → point electrodes T _a1 → ground → point electrodes other than point electrodes T _a1 and field controlling dedicated electrode 13b → the AC power source 4. (2) Electrode switching device 15 → Point electrode _Ta1 → Protective layer 3 → Correcting electrode 13a → Current measuring device 5 → One of AC power supply 4
a. (3) Electrode switching device 15 → point electrode _Ta1 → water leakage L → surface electrode 1
2 → current measuring device 5 → one 4a of AC power supply 4. (4) A circuit of the electrode switching device 15 → point electrode _Ta1 → protective layer 3 (or ground) → surface electrode 12 → current measuring device 5 → one of 4a of the AC power supply 4 is formed.

Then, the current measuring device 5 (the current detecting circuit 1)
6) measures the current values of the circuits (2) to (4) and outputs them to the computer 19 via the phase detection circuit 17 and the A / D converter 18. Then, the computer 19 stores the current value in the RAM together with "i = 1" (step 10).
3). The phase detection circuit 17 performs detection with a phase synchronized with the voltage applied to the power amplification circuit 41, and
A current having the same wavelength and the same phase as the applied voltage is extracted, and natural current and harmonic noise are removed from the current value.

Next, the computer 19 determines whether or not the selection switching procedure has been completed up to the 100th (i = 100; point electrode T _j10 ) (step 104), and if i = 100 (step 104: YES). , And performs the processing from step 105 onward. On the other hand, unless i = 100 (step 104: NO), the processing of step 106 is performed.

In step 105, the computer 1
9 increments the i-th by 1 (i = i +
1) Repeat the processing of step 102 and subsequent steps. That is, the computer 19 determines that “i = 1” to “i = 10”.
The current values detected in the processes up to “0” are stored.

In step 106, the computer 1
Numeral 9 corrects the current flowing through the protective layer 3 based on the current value stored in the RAM (correction means). Next, this correction processing will be described.

[Description of Correction Process] The current flowing through the surface electrode (current measuring electrode) 12 in the water shield structure 1 is the current flowing through the water leakage L, the current flowing through the protective layer 3 and the water shield 2 The current flowing through is included. The potential of the portion of the protective layer 3 that is in contact with the ground is located near the portion where the protective layer 3 is in contact with the ground because the thickness of the protective layer 3 is substantially uniform. The tendency of the current set by the annular correction electrode 13a (see FIG. 7) and the tendency of the current component passing through the protective layer 3 through which the current flows to the plane electrode 12 (see FIG. 6).
Has a similar relationship except near the water leakage.

Therefore, as shown below, the current component flowing through the protective layer 3 can be erased by using the maximum value of the current flowing through the surface electrode 12 and the annular correction electrode 13a. As a result, a measurement result on water leakage shown in FIG. 8 can be obtained. The x-axis shown in the three-dimensional views of FIGS. 6 to 8 shows the arrangement of the “a” to “j” lines of the point electrode, and the y-axis shows the arrangement of the “1” to “10” lines of the point electrode. And the z-axis shows the current value.

That is, the measurement result of the current value from FIG.
It shows that the current value flowing through the water leakage L and the current value flowing through the protection layer 3 are included. Also,
In this embodiment, by providing the annular correction electrode 13a and the electric field control electrode 13b, the upper and lower electric fields of the water shield 2 are controlled so as to have the same potential. It can be seen that the flowing current is reduced. However, this alone cannot eliminate the influence of the current flowing through the protective layer 3.

On the other hand, the annular correction electrode 13 shown in FIG.
The measurement result of the current flowing through “a” is very similar to the tendency of the measurement result of the current value measured by the surface electrode 12 (see FIG. 6) except for the vicinity of the water leakage, and the current flows to the protective layer 3. This indicates that the current is large. In addition, what is measured via the correction electrode 13a (circuit (2)) is disposed near the portion where the correction electrode 13a is in contact with the protective layer 3 or the ground around the water-impervious structure 1. Therefore, the tendency of the current value is considered to be substantially the same as the tendency of the current flowing through the protective layer 3.

Therefore, the current I flowing through the plane electrode 12 and the annular correction electrode 13a is expressed as I _meas. (X, y) and I _cir. (X, y) for the applied electrode position (x, y) _. . Then, the current I _meas. (X, y) flowing through the plane electrode 12 includes a current component I _pro. (X, y) flowing through the protective layer 3 as shown in FIG _.
And a current component I _leak. (X, y) flowing through the water leak L.

Therefore, the tendency of the current component passing through the protective layer 3 through which the current flows to the surface electrode 12 (see FIG. 6) and the tendency of the current set by the annular correction electrode 13a (see FIG. 7) are as follows. It can be seen that the characteristics of the outer peripheral portion of the measurement range (current component passing through the protective layer 3) are almost the same and similar.

The current I _cir. (X, y) flowing through the annular correction electrode 13a is a current component I _pro.
Expression (1) and Expression (2) can be expressed using the similarity k of (x, y). _{I meas. (X, y)} = I leak. (X, y) + I pro. (X, y) ... Equation _{1 I cir. (X, y} ) = k · I pro. (X, y) ... Equation 2 As can be seen from FIGS. 6 and 7, the influence of the current passing through the protective layer 3 becomes remarkable when the applied electrode is located around the outer periphery of the measurement range. The value is measured under the condition that the applied electrode is at the outer periphery of the measurement range.

Therefore, in Equation 1, the position of the applied electrode
(x, y), the maximum value of the current component I _pro. (x, y) flowing through the protective layer 3 is defined as I _pro.max, and the current I _{cir. Assuming} that the maximum value of (x, y) is I _cir.max , it is expressed by Expression 3. I _cir.max = k · I _pro.max Equation 3

Next, Equation 4 is obtained by eliminating the similarity ratio k from Equations 2 and 3. I _cir. (X, y) / I _cir.max = I _pro. (X, y) / I _pro.max Equation 4 Then, I _pro. (X, y) in Equation 1 is deleted by Equation 4. , equation 5 is obtained rewriting the current component I _{l eak} flowing through the _leak. (x, _y). I _leak. (X, y) = I _meas. (X, y) − ｛I _pro.max / I _cir.max ｝ · I _cir. (X, y)… Equation 5

Next, the computer 19 outputs to the CRT device a command to display the corrected measured value on the CRT screen (step 107). Then, the CRT device displays the measured values from “i = 1” to “i = 100” at the intersection of the CRT screen (see FIG. 8). Then, it can be seen that the effect of the current flowing through the protective layer 3 can be completely removed by the correction processing in step 106, and a three-dimensional view in which the leak location becomes clear is obtained.

That is, the points L1, L2, L3
When the leaked current is displayed (see FIG. 2B and FIG. 8), the corrected current value indicates that the point electrode close to the breakage point L1, L2, L3 of the water shield 2 shows a large value. As the point electrode moves away from the damage location L1, L2, L3 of the water shield 2, a tendency that the current value becomes smaller is displayed, and it becomes possible to know the water leakage occurrence positions L1, L2, L3.

When the measured value is displayed on the CRT screen, the computer 19 ends the water leak occurrence position detecting process.

According to this embodiment, as in the above-described example of the current value correction, the characteristics of the current flowing through the protective layer 3 are grasped by using the annular correction electrode 13a, so that the current flowing through the water leakage can be prevented. It is configured to perform correction to extract only the current (circuit (3)) flowing and detect the position where water leakage occurs. Therefore, the water shield 2 is damaged and the positions L1, L2, L3
In the case where water leakage occurs, only the current flowing through the water leakage can be extracted, so the current value flowing between the point electrode and the surface electrode near the water leakage occurrence position L1, L2, L3 is smaller than the current value between the other electrodes. The rise can be clearly detected, and the detection accuracy of the water leakage occurrence positions L1, L2, L3 is improved.

Further, according to this embodiment, by arranging the annular electrodes 13a and 13b, it is possible to measure the current passing through the surface electrode 12 under the condition that the potential inside and outside the water-blocking structure 1 becomes the same potential. Then, since the inside and outside of the measurement target (water shield 2) are controlled to the same potential except for the vicinity of the application electrode, the current flowing through the protective layer 3 can be reduced.

In this embodiment, the measurement target for detecting the position where the water leak has occurred has been described as the current value. However, the measurement target of the present invention is not only the current value but also the electric resistance value obtained from the measurement current value and the applied voltage. There may be.

Further, in this embodiment, the power supply 4 is described as a two-phase AC power supply in which the signal waveform of the oscillation circuit 42 is amplified by the power amplification circuit 41, but the power supply may be an alternating DC power supply. Although the application side of the power supply 4 is described in FIG. 1 as being installed on the ground side of the water shield 2, it may be an electrode in the water shield structure 1 in principle.

[0061]

According to the present invention, the characteristics of the current flowing through one of the ring electrodes are similar to the characteristics of the current flowing through the protective layer among the characteristics of the current measured by the current measuring electrode. As a result, the current flowing through the protective layer can be corrected.

Further, according to the present invention, since the inside and outside of the object to be measured are controlled to the same potential except for around the application electrode, the current flowing through the protective layer can be reduced.

Further, according to the present invention, the current flowing through the protective layer can be controlled by the current measuring electrodes (a plurality of line electrodes or plane electrodes) and the annular electrodes provided so as to surround the installation area of the point electrodes. It can be further reduced.

Therefore, according to the present invention, by grasping the characteristics of the current flowing through the protective layer, a correction is performed to extract only the current flowing in the water leak, and a correction function having a correction function for improving the accuracy of detecting the position where the water leak occurs is provided. An occurrence position detection device and a method thereof can be provided.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a seepage control structure.

2A and 2B are plan views of a water impervious structure, in which FIG. 2A shows a plane arrangement of plane electrodes, and FIG. 2B shows a plane arrangement of point electrodes.

FIG. 3 is a block circuit diagram of a part of the water leakage occurrence position detecting device according to the present invention.

FIG. 4 is an enlarged view of a point electrode.

FIG. 5 is a flowchart of a water leakage occurrence position detection process according to the present invention.

FIG. 6 is a three-dimensional view showing a measurement result of a current value.

FIG. 7 is a three-dimensional view showing a measurement result of a current value flowing through an annular correction electrode.

FIG. 8 is a three-dimensional view when the measurement result of FIG. 6 is corrected by using a correction electrode.

FIG. 9 is a block circuit diagram of a conventional water leakage occurrence position detecting device.

FIG. 10 is a side sectional view of a conventional waterproof structure, showing a state in which current flows through a protective layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Water shielding structure 1a ... Depression 2 ... Water shielding 3 ... Protective layer 4 ... AC power supply 5 ... Current measuring device 12 ... Surface electrode 13a ... Correction electrode (annular electrode) 13b ... Electric field control electrode (annular electrode) 15 ... Electrode switching device 16 ... Current detection circuit 17 ... Phase detection circuit 18 ... A / D converter 19 ... Computer (correction means) 41 ... Power amplification circuit (two-phase AC power supply) 42 ... Oscillation circuit

Claims (4)

[Claims] An impermeable structure having an electrically insulating water impervious structure laid in a depression formed in the ground and a protective layer for conducting electricity provided in a layer on the water impervious structure. A surface electrode installed on either side of the surface, a plurality of point electrodes installed on the opposite side of the surface electrode, and the plurality of point electrodes or the surface electrode near a portion where the protective layer contacts the ground. An annular electrode provided surrounding the periphery of, and one selected from the plurality of point electrodes and connected to one end of a power source, and all the point electrodes except the selected point electrode;
Selective connection means for connecting the surface electrode and the ring electrode to the other end of the power supply; current measurement means for measuring a current flowing between the selected point electrode and the surface electrode and the ring electrode; Correction means for correcting a current component flowing through the protective layer from the measured current value of the surface electrode using the measured current value of the electrode, and wherein the corrected current value and the position of the selected point electrode are provided. A water leak occurrence position detecting device for detecting a water leak position of the water impervious structure. 2. A power supply according to claim 1, wherein a plurality of said annular electrodes are provided, and said at least one annular electrode is connected directly to the other end of said power supply by said selective connection means bypassing said current measuring means.
The leak detection position detecting device according to the above. 3. The water leakage occurrence position detecting device according to claim 1, wherein the current measuring means has a phase detection circuit for extracting a current component having the same wavelength and the same phase as the applied voltage of the power supply. 4. A water impervious structure, wherein a water impervious work of an electrical insulator is laid in a depression formed in the ground, and a protective layer for conducting electricity is provided in a layer on the water impervious work to form a water impervious structure. A surface electrode is installed on either side of the surface electrode, a plurality of point electrodes are installed on the opposite side of the surface electrode, and a portion of the plurality of point electrodes or the surface electrode near the portion where the protective layer contacts the ground. An annular electrode surrounding the periphery is arranged, one of the plurality of point electrodes is selected and connected to one end of a power supply, and all the point electrodes except the selected point electrode are provided.
Connecting the surface electrode and the annular electrode to the other end of the power supply, measuring a current flowing between the selected point electrode and the surface electrode and the annular electrode, using a measured current value of the annular electrode Correcting a current component flowing through the protective layer from a current value measured at the surface electrode, and detecting a water leakage position of the water shield structure from the corrected current value and the position of the selected point electrode. A method for detecting a position at which a water leak has occurred.