JP2003194657A - Water leak spot detection method of sealing works - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily detect a damaged spot without reducing pressure by using an ultrasonic transmission/reception means, and to put water leak detection by an ultrasonic reception of this kind to practical use by effectively utilizing an existing water collection/drainage pipe. <P>SOLUTION: This method has an ultrasonic transmission means 8 for transmitting an ultrasonic wave by being inserted into the back side of a sealing work 3, and an ultrasonic reception means 9 placed on the surface side of the sealing work 3 and carried by an inspector. In the method, a damaged position A of the sealing work is detected and specified from the difference of the sound pressure level of the ultrasonic wave received by the ultrasonic reception means 9 on the surface of the sealing work 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of detecting water leakage in a water shield work, and more particularly to a method using ultrasonic wave transmitting / receiving means.

[0002]

2. Description of the Related Art If there is a construction failure in the seam of a water-blocking sheet used as a water-blocking construction for a waste disposal site or a reservoir, or if it is damaged by external factors even after the construction, The water stored inside the seepage control works penetrates underground through these damaged points, causing groundwater pollution especially at the waste disposal sites, so it is necessary to strictly manage the construction.

As one of the management systems, there is a system in which electrodes are arranged above and below a water-blocking sheet and water is leaked when a potential difference occurs between the electrodes. Placement and routing of the code accompanying this,
In addition to the need for an analyzer for measuring results, the equipment cost is high, and when the water leak location is dry, electricity does not flow and is not detected.

Further, as another management system, there is a physical type (downflow type) detection system in which a water collection and drainage pipe is installed between double water shield sheets. In this system, an impermeable layer is provided between double impermeable sheets, and a drainage pipe is installed in this impermeable layer.
If there is water leakage, this is a detection system that uses the fact that it flows down the collection and drainage pipe.

In this system using the water collection and drainage pipe, the area in which the water blocking work is laid is divided into several places, and the water collection and drainage pipe is arranged in each of the areas.

After the area where water has leaked is specified using this system, the detection is specified by visual confirmation or by listening to the air inflow sound generated from the damaged portion at the time of decompression. The above method had the following problems.

[0007]

When searching by visual inspection, it is difficult to find if there are few faulty construction sites or damaged sites, especially when a non-woven fabric for both light shielding and sheet protection is laid on the surface of the waterproof sheet. I can't find it first.

Further, as one of the visual inspection methods, there is a method of applying soapy water to the inspection location, covering the area with a box to depressurize the interior, and identifying the location where bubbles are generated, as in the tire puncture repair method. However, it is not applicable because it cannot be sucked in an uneven place or when a non-woven fabric is laid. Furthermore, it is unrealistic because the box is too small to inspect the entire surface of the water shield and it takes time to find it. .

The present invention is intended to solve the above problems, and an object of the present invention is to provide a method for detecting water leakage in a water-shielding work in which a damaged portion can be easily detected by using ultrasonic transmitting / receiving means. Is provided.

[0010]

In order to achieve the above object, the method of the present invention is inserted into a water collection and drainage pipe which is provided on the back side of a water shield work laid on the ground such as a waste disposal site or a reservoir. Ultrasonic wave oscillating means for oscillating ultrasonic waves, and ultrasonic wave receiving means arranged on the surface side of the water shield work. The feature is to detect and identify the damaged position of the water shield by the difference in sound pressure level.

That is, according to the present invention, the water shield is made of a sheet material having a high sound insulation property such as a rubber sheet, and the transmitted ultrasonic waves are transmitted by the water shield and are received by the receiving means. The sound pressure level of ultrasonic waves becomes low, and on the contrary, the sound pressure level of a place without water shield is abnormally higher than that of the other place, and the transmitted and received ultrasonic bands are the same, and the directivity is also This was done by focusing on the fact that other noise is not picked up because it is expensive. Therefore, in the present invention, an expensive management system is not required, and the damaged portion can be detected and specified more easily than the conventional visual confirmation method or hearing method. And, since the ultrasonic oscillating means is to be inserted into the water collection and drainage pipe that is piped on the back surface of the water shield, when inserting the ultrasonic oscillating means on the back surface of the water shield, the water shield is cut off, You can save the trouble of making holes.

[0012]

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Figure 1,
2 shows a part of a waste disposal site to which the method for detecting water leakage according to the present invention is applied. In this disposal site 1, a water-permeable sheet 2 such as a non-woven fabric is laid on the upper surface of the ground E that has been leveled,
A lower side water-impervious sheet 3 is laid on the upper surface, and a sand layer 4 having a predetermined thickness is formed on the upper surface, and then a sand layer 4 having a predetermined thickness is formed on the upper surface. The drainage pipe 6 is buried, and the upper water-permeable sheet 2 and the water-impermeable sheet 3 are laid on the upper surface of the sand layer 4, and the uppermost layer is covered with the water-permeable sheet 2 to form a double water-impervious structure.

The collection / drainage pipe 6 is a perforated pipe which is laid at a plurality of locations in the disposal site 1, and the downstream end of the collection / drainage pipe 6 is communicated with a drainage pit 7 for water quality inspection and accumulated at the upper part. If the upper water-blocking sheet 4 is damaged by the waste and the leachate permeates into the sand layer 4, the leachate flows into the drainage pit 7 through the drainage pipe 6, while no further leachate occurs. By stopping with the lower side water-blocking sheet 3, the permeation to the ground E side can be prevented in advance.

In the above structure, at the time of inspecting a damaged portion, the ultrasonic transmitter 8a of the ultrasonic oscillator 8 is inserted through the drainage pit 7 into the inside of the tip of the water collection and drainage pipe 6 and oscillates ultrasonic waves at the same time when the inspection is started.

On the other hand, the water collection and drainage pipe 6 on the upper side impermeable sheet 3
An inspector is placed near the pipe position. The inspector carries the ultrasonic receiver 9 and walks in a zigzag along the vicinity of the pipe position of the water collecting and draining pipe 6 while sliding the sound collecting casing 10 with the long handle 10a on the ground surface. There is.

An ultrasonic wave receiver 9a connected to the receiver 9 is built in the casing 10 so as to detect an ultrasonic wave oscillating sound near the surface of the earth.

As described above, when the water-impervious sheet 3 has a damaged portion A, ultrasonic waves leak from that position. Therefore, when the inspector passes near the damaged portion and the receiver 9a detects this, the receiver 9 receives the ultrasonic wave intensity higher than the ultrasonic wave intensity at the normal position.

Based on this, the inspector further slides the casing 10 from this position, and by capturing the position at which the highest ultrasonic intensity is displayed, this position can be detected and specified as the damaged portion A. After detection, repair work can be performed by marking this part.

In the above-mentioned detection method, the ultrasonic intensity can be displayed by the inspector visually observing the shake of the pointer of the indicator provided in the ultrasonic receiver 9, and the ultrasonic intensity increase can be detected. In addition, it is possible to add a function of generating an alarm sound when a certain intensity is exceeded or blinking an indicator lamp to call attention to an inspector.

Further, as the inspector moves away from the sound source, the sensitivity on the receiver 8 side is increased or the oscillation intensity on the oscillator 7 side is increased, so that a constant inspection is performed at any position. In order to do so, before the water-blocking sheet 3 is laid, the ultrasonic wave level at each position is previously inspected, and the relationship between the distance from the sound source along the water collection and drainage pipe 6 and the ultrasonic wave intensity is determined. Just keep it.

Further, in the embodiment, the wave receiver 9a is provided with a long handle 10.
It is built in the sound collecting casing 10 with "a", and the inspector has the long handle 10a so that the casing 10 can be inspected while sliding the casing 10 on the ground surface. However, these practical accessory devices can be freely changed.

Further, in the embodiment, the case of inspecting in the vicinity of the water collection and drainage pipe 6 has been described. However, in the case of performing this type of inspection at a position distant from the water collection and drainage pipe 6, the inspection is performed as follows.

First, when the end of the water-blocking sheet 3 is not blocked during the construction of the water-blocking work, the wave-transmitter 8a is inserted into the back side of the water-blocking sheet 3 so that the front side Inspect from. Further, after the construction, holes may be made in the wave impervious sheet 3, the wave transmitter 8a may be placed on the back side thereof, the inspection may be performed from the front side, and this portion may be closed after the inspection.

[0024]

As is apparent from the above description, in the method for detecting a leaking point in a water shield work according to the present invention,
By using the ultrasonic wave transmitting / receiving means, an expensive management system is unnecessary, and the damaged portion can be detected reliably and easily.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing a case where a leak detection method according to the present invention is applied to a waste disposal site.

FIG. 2 is an explanatory longitudinal cross-sectional view showing the tip position of the water collection and drainage pipe at the same disposal site.

[Explanation of symbols]

3 impermeable sheet 5 crushed stone 8 Ultrasonic oscillator (ultrasonic oscillator) 8a wave transmitter 9 Ultrasonic receiver (ultrasonic receiving means) 9a Receiver A damaged part

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kanetaka Namiki             4-22 Asakusabashi, Taito-ku, Tokyo Taiyo             Kogyo Co., Ltd. F-term (reference) 2G067 AA48 BB02 BB14 BB26 CC02                       DD13 EE05                 4D004 BB05 BB06

Claims (2)

[Claims] 1. An ultrasonic oscillating means for oscillating an ultrasonic wave by being inserted into a water collection and drainage pipe laid on the back side of a water blocking work laid on the ground such as a waste disposal site or a reservoir, and the water blocking work. And an ultrasonic wave receiving means arranged on the front surface side of the water shielding work, and the damage position of the water shielding work is detected and specified by the difference in the sound pressure level of the ultrasonic waves received by the ultrasonic wave receiving means on the surface of the water shield work. A method for detecting a leak location in a water barrier construction. 2. The method for detecting a leaked portion in a water shield work according to claim 1, wherein the ultrasonic wave oscillating means is an object carried by an inspector.