JPH09318482A - Detecting method of position of water leakage of sealing sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To check surely the position of water leakage of a sealing sheet by a method wherein a pulse is generated in one of adjacent sensor materials and the position of the water leakage is detected from a response waveform coming back to the other sensor material. SOLUTION: When a sealing sheet 4 is impaired, percolating water collected in a disposal plant passes through a place 6 of impairment, permeates into an inside fibrous part and soon spreads to a line 7 formed of two adjacent sensor materials 3a and 3b and this is detected by a leakage current detector. In order to specify the line, subsequently, each set of the adjacent sensor materials 3a and 3b is checked up sequentially as to whether an electric current can pass through or not, by the leakage current detector, and thereby the line 7 at which the water leaks is specified. An oscilloscope 9 being connected to the specified line 7, a pulse is generated in one sensor material 3a and the place of water leakage is detected from a response waveform 10 coming back to the other sensor material 3b. Since a large waveform is obtained from the place 6 of water leakage, this place can be indexed in an order of several centimeters on the oscilloscope.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for detecting and confirming the breakage portion of the water-blocking sheet laid on the exposed surface of a general waste disposal site, an industrial waste disposal site, a contaminated soil disposal site, or the like. The present invention relates to a leak position detecting method.

[0002]

2. Description of the Related Art In recent years, leakage of water from a final disposal site for containing wastes, contaminated soil, etc. contains harmful substances, and pollution of groundwater and river water due to this has become a social problem. The cause is considered to be water leakage from the water-blocking sheet laid on the exposed surface of the final disposal site, which broke for some reason. Conventionally, as a method of detecting this breakage point, at the disposal site that requires a water-blocking structure with a water-blocking sheet, the property that the water-blocking sheet is insulative is utilized, and electric wires (electrodes) are placed above and below the sheet. They are arranged in a grid pattern, and once a hole is formed in the sheet, the electrical characteristics of that part change due to water leakage, so the position of water leakage can be detected.

[0003]

However, in the above-mentioned conventional breakage point detecting method, it is necessary to arrange the electric wires (electrodes) in a grid pattern on or under the sheet, and the labor and time for the construction are complicated and time-consuming and costly. However, there is a problem that it is difficult to secure quality because there are many field wirings. In reality, a method is adopted in which wiring is provided on the upper side of the sheet, and there is a problem in durability due to damage from landfill waste from the upper side and corrosion due to leachate.

The present invention solves the above-mentioned conventional problems, and is a simple detection method and at low cost, the leak position of the waterproof sheet can be surely confirmed, and the leak position of the waterproof sheet can be detected. The purpose is to provide a method.

[0005]

Therefore, in the method for detecting the water leakage position of a water-blocking sheet according to the present invention, a plurality of sensor materials composed of a reinforcing fiber portion and a conductive wire are sandwiched between upper and lower insulating sheets. A method of detecting a water leak position of a water blocking sheet is characterized in that a pulse is generated in one of adjacent sensor materials and the water leak position is detected by a response waveform returned to the other sensor material.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B show the structure of a water blocking sheet according to the present invention, FIG. 1A is an exploded perspective view showing a part of the water blocking sheet, and FIG. 1B is a diagram showing a wire connection structure of a sensor.

In FIG. 1 (A), a water blocking sheet 4 is laid on the bottom surface of a disposal site for containing wastes, contaminated soil, and the like. The water-blocking sheet 4 has a four-layer structure in which a plurality of sensor materials 3 and 3 composed of a reinforcing fiber portion 2 and a conductive wire material are sandwiched between upper and lower insulating sheets 1 and 1. As shown in FIG. 1B, the plurality of sensor materials 3 are arranged in parallel, every other adjacent sensor materials 3a and 3b are connected to the wirings 3c and 3d, respectively, and the leakage current flows to the wirings 3c and 3d. The detector 5 is connected.

FIG. 2 is a diagram for explaining the overall processing flow of the method for detecting the water leakage position of the water-blocking sheet according to the present invention,
FIG. 3 is a diagram for explaining the processing of steps S1 and S2 of FIG. First, in step S1, it is detected whether or not the waterproof sheet 4 is damaged. This is performed by connecting the leakage current detector 5 to the connection lines 3c and 3d as shown in FIG. The leakage current detector 5 detects whether or not electricity is applied to one connection line and the other connection line is energized. If the water-blocking sheet 4 is not damaged, the leakage current detector 5 detects the current. do not do. It is also possible to confirm whether or not the sensor material is broken by measuring the electric current at both ends of the sensor material.

As shown in FIG. 3 (A), when the water-blocking sheet 4 is damaged, the leachate accumulated in the disposal site passes through the damaged part 6 and oozes into the fiber part 2 inside, and eventually the adjacent 2 When the leak current detector 5 applies a current to one sensor material by the leak current detector 5, a current flows to the other sensor material, which is detected by the leak current detector 5, resulting in the interruption. It can be detected that there is water leakage somewhere on the water sheet 4.

When it is detected that there is water leakage somewhere on the water-blocking sheet 4, the line at the water leakage position is specified in step S2. Each sensor material 3 is collected from the end of the sheet to the leakage current detector 5 by wiring.
As shown in (B), the leakage current detector 5 checks each pair of adjacent sensor materials 3a and 3b whether or not to energize, and the leaked line 7 is specified.

When the leaking line 7 is specified, next, in step S3, the leaking position, which is a feature of the present invention, is detected. FIG. 4 is a diagram for explaining one embodiment of a water leakage position detecting method for a water blocking sheet according to the present invention. Connect the oscilloscope 9 to the specified line 7 and use one of the sensor materials 3
A pulse is generated in a, and the water leakage point is detected by the response waveform 10 (pulse value) returned to the other sensor material 3b. Since a large waveform is obtained at the water leakage point 6, the water leakage point can be determined on the oscilloscope 9 on the order of several centimeters. Even if there are two or more breaks, it is possible to confirm the peaks 6a and 6b of the response waveform 10 as shown in FIG.

[0012]

As is apparent from the above description, according to the present invention, it is possible to reliably confirm the water leakage position of the water blocking sheet with a simple detection method and at low cost. Also,
In addition to monitoring during landfill, it can also be used as an inspection at completion,
Even if a problem occurs after that, the suspicion of defective construction can be resolved, and the reliability can be improved.

[Brief description of drawings]

FIG. 1 shows the structure of a waterproof sheet according to the present invention, and FIG.
(A) is an exploded perspective view showing a part of the water-blocking sheet, FIG.
(B) is a diagram showing a connection structure of the sensor.

FIG. 2 is a diagram for explaining an overall processing flow of a water leakage position detecting method for a water blocking sheet according to the present invention.

FIG. 3 is a diagram for explaining the processing of steps S1 and S2 of FIG.

FIG. 4 is a diagram for explaining one embodiment of a water leakage position detecting method for a water blocking sheet according to the present invention.

FIG. 5 is a diagram showing a response waveform.

[Explanation of symbols]

1 ... Sheet, 2 ... Fiber part, 3 ... Sensor material, 4 ... Water blocking sheet 9 ... Oscilloscope, 10 ... Response waveform

Front page continuation (72) Inventor Yuji Onishi 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation

Claims (1)

[Claims] 1. A method of detecting a water leakage position of a water-blocking sheet, comprising a plurality of sensor materials composed of a reinforcing fiber portion and a conductive wire material sandwiched between upper and lower insulating sheets, wherein one of adjacent sensor materials is used. A method for detecting a leak position of a water-blocking sheet, which comprises detecting a leak position with a response waveform returned to the other sensor material.