JP4393877B2 - Inspection method for inspecting damaged parts of the water shielding sheet - Google Patents

Description

  The present invention relates to an inspection method for inspecting a damaged portion of a water shielding sheet.

The waste disposal site has a concave surface provided by digging the ground or constructing a lift wall, and the waste is sequentially buried from the bottom. In this waste disposal site, it is extremely important to prevent the sewage generated from the waste dumped in the concave surface from diffusing into the external soil, and various techniques are used for this purpose.
The most widely used for preventing the diffusion of sewage is to lay a water shielding sheet over the entire concave surface. By laying a water shielding sheet made of a synthetic resin sheet or rubber sheet having a high water shielding performance over the entire concave surface, external diffusion of sewage is prevented.
In actuality, the water-impervious sheet is laid by sequentially joining sheet materials provided with water-imperviousness.

  As a method for joining the sheet materials, there is a method in which the ends of the adjacent sheet materials 2 are overlapped with each other, and both ends of the overlapped portions are thermally welded so as to have the hollow portion 30 as shown in FIG. Moreover, the edge part of the adjacent sheet | seat material 2 is piled up, this overlapping part is heat-welded, resin 40 is piled up on the edge part of the sheet | seat material 2 located above an overlapping part, and it joins like FIG. is there.

When such a water-impervious sheet is damaged, the water-impervious sheet cannot exhibit its water-impervious function, so it is necessary to inspect the presence or absence of a damaged part.
Although damage may occur in a part of the sheet material, in the case of a water shielding sheet configured by joining a plurality of sheet materials as described above, there is a possibility that damage may also occur in the joint portion that is the joint location. There is.
In general, the inspection of whether or not the water-impervious sheet is damaged is visually performed. Of the above-described sheet material joining methods, a hollow needle is inserted into the cavity portion 30 formed by joining, and air is introduced into the cavity portion through the former, for the joined portion joined by the former joining method. The joint is inspected for damage depending on whether the pressure loss is equal to or less than a predetermined value. In addition, among the joining methods of the sheet material described above, for the joined portion joined by the latter joining method, after spraying soapy water around the joined portion, the portion is covered with a box and sealed, The sealed space is depressurized with test equipment, and the presence or absence of damage at the joint is inspected based on whether or not bubbles are generated within a predetermined time.

However, since visual inspection is effective only for a visible portion, that is, a surface portion of the water shielding sheet, there is a limit.
In addition, among the above-described sheet material joining methods, in the inspection of the joint portion by the former joining method, since it is necessary to perform inspection for each side of the sheet material, it takes much labor and time, and the cost burden is also high. Tend to be oversized. Even if it can be found that there is breakage, it is difficult to specify the specific position where breakage occurs, and pressurization itself may cause breakage.
Further, among the above-described sheet material joining methods, the inspection for the joint portion by the latter joining method requires repeated inspection while shifting the box, so that the inspection for the joint portion by the former joining method is performed once. While the inspection can be performed on the entire side of the sheet material, the inspection can be performed only on a part of the side of the sheet material. Therefore, the labor, time, and cost for the inspection tend to be excessive.
In short, the inspection of these joints tends to be excessive in terms of labor and cost.

  In view of the above, it is an object of the present invention to propose a technique for easily inspecting a water shielding sheet, particularly a damaged portion of a joint portion thereof.

An inspection method for inspecting a damaged portion of the water-impervious sheet of the present invention for solving such a problem is as follows.
That is, an inspection method for inspecting a breakage point of a water shielding sheet for preventing leakage from the concave surface of leachate generated from the waste, which is laid on a concave surface where waste is buried. The method includes imaging a temperature distribution of a surface of a portion to be inspected in the water shielding sheet by thermography.
When the water shielding sheet is damaged, the thermal conductivity is different between the damaged portion and the vicinity thereof. For this reason, when the temperature of the water-impervious sheet changes, a temperature difference based on the difference in thermal conductivity occurs on the surface of the water-impervious sheet.
The inspection method of the present invention pays attention to such a mechanism, and inspects a damaged portion by detecting a temperature difference on the surface of the water shielding sheet.
That is, the inspection method of the present invention uses thermography (for example, a portable thermal infrared image measurement device) that is a device that measures and records the temperature distribution of an object to be imaged. The method includes imaging the surface temperature distribution of the portion to be inspected by thermography.
According to the inspection method of the present invention, the temperature difference of the surface of the water shielding sheet can be detected from the image showing the temperature distribution of the water shielding sheet obtained by thermography. By visually observing the image, the damaged part can be detected. In addition, it is possible to grasp the breakage of a portion other than the surface, that is, a portion that cannot be visually recognized.
In addition, depending on the range in which an image is taken, it is possible to deal with a wide range with a single inspection, so the work load can be reduced.
Further, not only the presence / absence of breakage of the joint portion but also the breakage point can be specified.
Furthermore, since the taken image can be saved, the damaged part can be confirmed later.

The water-impervious sheet is configured by joining a plurality of sheet materials provided with water-impervious properties, and the portion to be inspected may include a joined portion obtained by joining the sheet materials. .
Such an inspection can also be easily performed as described above.
Furthermore, if it carries out like this, since it is not necessary to pressurize or apply a negative pressure with respect to each junction part conventionally, it is not damaged.

The inspection of the damaged portion of the water shielding sheet as described above can be performed when the entire temperature of the water shielding sheet is not uniform.
Since the thermal conductivity is different between the damaged portion and the other portions, a temperature difference occurs when the temperature of the water shielding sheet rises or falls. From this, if an inspection is performed when the temperature of the entire water shielding sheet is not uniform, a temperature difference can be detected, and a damaged portion can be inspected.

The inspection of the damaged portion of the water shielding sheet may be performed, for example, when the temperature of the water shielding sheet is increased.
Since the temperature difference between the damaged part and the other part becomes remarkable when the temperature of the water shielding sheet rises, if the above inspection is performed when the temperature of the water shielding sheet rises, the damaged part can be inspected more accurately. . For example, it can be inspected at the time when the temperature of the water shielding sheet gradually increases due to solar radiation, such as at dawn or when the sun is seen from the clouds.
Of course, even when the temperature of the water-impervious sheet is lowered, a temperature difference occurs between the damaged part and the other part. Therefore, the inspection of the damaged part of the water-impermeable sheet may be performed when the temperature of the water-impervious sheet is lowered. For example, the inspection can be performed at a time zone in which the temperature of the water shielding sheet gradually decreases, such as at dusk or when the sun is hidden behind a cloud.

In addition, the inspection of the damaged portion of the water shielding sheet can be performed after the temperature of the water shielding sheet is forcibly lowered when the temperature of the entire water shielding sheet becomes uniform.
When the temperature of the entire water-impervious sheet is raised by solar radiation, the temperature at the damaged part and the other parts are slightly different, so it is difficult to accurately inspect the damaged part. Therefore, if the inspection is performed after the temperature of the water shielding sheet is once lowered, the inspection can be performed when the temperature of the water shielding sheet is increased.
In order to lower the temperature of the water shielding sheet, for example, a method of spraying water on a portion to be inspected of the water shielding sheet or a method of applying cold air to the water shielding sheet is effective.
Conversely, if the temperature of the entire impermeable sheet has dropped, for example, spraying warm water on the inspected portion of the impermeable sheet or applying warm air to the impermeable sheet You may test | inspect a damaged part, after raising the temperature of a sheet | seat compulsorily.

The inspection of the damaged portion of the water shielding sheet may be performed while forcibly raising the temperature of the water shielding sheet and then forcibly lowering the temperature.
That is, if the inspection is performed while the temperature of the water shielding sheet is once increased and then decreased, the inspection can be performed when the temperature of the water shielding sheet is decreased.
Specifically, for example, the temperature of the water shielding sheet is forcibly increased by a dryer or the like, and then water is sprayed on a portion to be inspected of the water shielding sheet to perform the inspection.
Further, the inspection of the damaged portion of the water shielding sheet may be performed while forcibly lowering the temperature of the water shielding sheet and then forcibly increasing the temperature.
That is, once the temperature of the water shielding sheet is lowered and then the inspection is performed while the temperature is raised, the inspection can be performed when the temperature of the water shielding sheet is increased.
Specifically, for example, by spraying water on the water shielding sheet, the temperature of the water shielding sheet is forcibly lowered, and then the inspection target portion of the water shielding sheet is warmed with a drier or the like to perform the inspection.

The inspection of the damaged portion of the water shielding sheet can be performed while moving the thermography.
Specifically, the movement of the thermography can be performed by using, for example, a wheeled carriage on which the thermography is mounted so that a water shielding sheet can be imaged.
If the inspection is performed while moving the thermography in this way, the work burden on the movement of the thermography can be reduced. In addition, the temperature distribution on the surface of the portion to be inspected can be continuously imaged.

The joint portion is formed by overlapping the end portions of adjacent sheet materials, and joining both end portions of the overlapped portion so that a cavity is formed between the both end portions. The inspection of the location may be performed in a state where the temperature of the joint portion is changed by passing hot air or cold air through the hollow portion.
If it carries out like this, the temperature of a junction part can be changed and a broken part can be made to stand out on an image. That is, it is possible to specify a specific position where there is a breakage. In addition, since the sent warm air or cold air passes through the inside of the hollow portion, the joined portion is not pressurized and the water shielding sheet is not damaged.
This method may be performed in a state where the temperature of the joint portion is changed, and may be performed while warm air or cold air is being fed into the hollow portion, or may be performed after the warm air or cold air is stopped being fed.

Another invention of the present application is a sheet material constituting a water shielding sheet for preventing leakage of leachate generated from the waste and leaking from the concave surface, which is laid on the concave surface where the waste is buried. An inspection method for inspecting a damaged part, wherein a temperature distribution of a surface of a part to be inspected is imaged by thermography in the sheet material, and the part to be inspected based on the image is damaged. This is an inspection method for inspecting a damaged portion of a sheet material.
The inspection for the presence or absence of a damaged portion is performed at a factory or the like before the laying of not only the water shielding sheet laid on the site as described above but also the sheet material constituting the water shielding sheet.
According to the inspection method of the present invention, the temperature difference on the surface of the sheet material is detected by an image showing the temperature distribution of the sheet material obtained by thermography, similarly to the inspection method of the damaged portion of the water shielding sheet. Therefore, the damaged part can be detected at a glance.

  According to the method for inspecting a damaged portion of the water-impervious sheet according to the present invention, it is possible to easily inspect the damaged portion of the water-impervious sheet, particularly its joint.

  Hereinafter, preferred embodiments of the method for inspecting a damaged portion of the water shielding sheet of the present invention will be described.

[First embodiment]
This method for inspecting a breakage point of a water shielding sheet is a method in which a thermography device images the surface temperature distribution of a portion to be inspected for a water shielding sheet and detects the breakage point of the water shielding sheet based on the image. is there.

The water-impervious sheet is laid on the concave surface where waste is buried, and prevents leachate generated from the waste buried in the concave surface from leaking from the concave surface, and is constructed by joining multiple sheet materials Has been.
The sheet material has water-insulating performance, and the material may be any material as long as it has water-insulating performance. For example, it can be constituted by high-density polyethylene. . The shape is not necessarily so, but is rectangular.
The sheet material is sequentially joined so that the water shielding performance can be maintained, and the water shielding sheet is laid by laying so as to cover the entire concave surface.
Joining between adjacent sheet materials is not limited to this, but in the present embodiment, as shown in FIG. 16, the end portions of the adjacent sheet materials 2 are overlapped so as to have a hollow portion 30. The two ends are joined by heat welding.

A thermography device is a device that detects a temperature distribution on the surface of a test object. The thermography apparatus of the present embodiment can detect a temperature distribution, display it as an image, and display / record it.
Specifically, it is configured to include a camera unit including a sensor that detects infrared rays emitted from the test object, and a signal processing unit that processes a signal from the camera unit and outputs the signal to a monitor or a flash memory. Has been. The signal processing unit includes a monitor and a flash memory. The monitor displays the temperature distribution in different colors based on the input data. The flash memory records and stores the input data.

In order to inspect the breakage point of the laid water shielding sheet using this thermography device, the camera part of the thermography device is installed at an arbitrary position, and the infrared rays radiated from the surface of the water shielding sheet by the sensor The radiant energy is measured without contact.
The measured signal is sent to the signal processing unit, and the infrared radiation intensity distribution, that is, the temperature distribution is displayed as an image on the monitor. In addition, this image data is stored on a disk in this embodiment.

  If the water-impervious sheet is damaged, the temperature of the surface of the water-impervious sheet changes when the temperature of the water-impervious sheet changes due to the difference in thermal conductivity between the damaged part and its vicinity. A person inspecting whether or not there is a place where there is a temperature difference in the image data obtained by the thermography apparatus evaluates and detects a damaged part.

In this way, if the thermography device images the temperature distribution of the surface of the portion to be inspected of the water shielding sheet, and detects the damaged portion of the water shielding sheet based on the image, it cannot be inspected by visual inspection. It is also possible to detect breakage at a location.
In addition, since a damaged portion can be detected at a glance and a wide range can be dealt with by a single inspection, it can be performed without taking time and effort as in the case of inspection of the pressure loss of the joint. That is, it is possible to reduce the work burden of the inspection for the joint.
Further, since the image data can be stored on the disk, the damaged part can be accurately grasped and confirmed later.

This inspection is not limited to this, but is performed when the entire temperature of the water shielding sheet is not uniform.
Specifically, it is performed in a time zone in which the temperature of the water shielding sheet rises or falls, which is a time zone in which the temperature difference between the damaged part and the other part becomes large.
In addition, when the temperature of the water-impervious sheet is increased and the entire temperature of the water-impervious sheet is uniform, the temperature of the water-impervious sheet may be forcibly lowered.
Moreover, after forcibly raising the temperature of the water shielding sheet, the inspection may be performed while forcibly lowering the temperature. On the contrary, after forcibly lowering the temperature of the water shielding sheet, the inspection may be performed while forcibly raising the temperature.

The above inspection can be performed on the water shielding sheet laid on the site in this way, and can also be applied in the same way to the inspection of the sheet material performed before laying in the factory that manufactures the water shielding sheet. it can.
Moreover, although the thermography apparatus of this embodiment was described as what was mentioned above, it is not restricted to this, What is necessary is just to be able to detect a temperature distribution at least.

<Example 1>
In this embodiment, a part of the water shielding sheet having a break (bonding failure, overfusion, non-integration) at the joint is used as a sample, and the trouble of the joint can be detected outdoors by a thermography device. Whether or not it was inspected.
As a sample used, a plurality of water shielding sheets having a thickness of 1.5 mm were cut out so as to include a joint portion and made 50 cm to 60 cm square. High density polyethylene (HDPE) or flexible polymer alloy (FDA) was used as the material of the water shielding sheet.
Similar to the water-impervious sheet of the above-described embodiment, the joint portion of these samples is thermally welded so as to have a hollow portion 30 as shown in FIG.
As shown in FIG. 1, as shown in FIG. 1, a thermography device is used to measure the temperature distribution of the surface of each sample that is heated outdoors by laying a non-woven fabric 11 and spreading a non-woven fabric 11, and laying a sample 12 thereon. This was carried out by measuring at 1. In this embodiment, the measurement wavelength of the thermographic apparatus 1 is set to 7.5 to 13 μm. In addition, the measurement distance was 1 m, the measurement angle was 45 °, and the measurement was performed around noon when the temperature of the water shielding sheet rose (sunny, temperature 29 ° C., humidity 49%, wind speed 4.4 m).
FIG. 2 is a thermal image of a sample (HDPE) having bonding failure on both sides of the bonding portion. 2 (a) is a photograph of a thermal image immediately after the start of measurement, FIG. 2 (b) is a photograph of a thermal image 5 minutes after the start of measurement, and FIG. 2 (c) is a photograph of the start of measurement. The photograph of the thermal image after 30-minute progress is shown. 2 (b) ′ and 2 (c) ′ are three-dimensional representations of the temperature distributions of FIGS. 2 (b) and 2 (c).
FIG. 3 shows a photograph of a thermal image of each sample immediately after the start of measurement and a photograph of a thermal image 30 minutes after the start of measurement.
FIG. 3A is a photograph of a thermal image of a sample (HDPE) having a bonding failure on one side of the bonding portion. FIG. 3B is a photograph of a thermal image of a sample (HDPE) in which the joint is overfused and the cross-sectional shape is abnormal. FIG. 3C is a photograph of a thermal image of a sample (HDPE) in which the joint portion is not integrated because the fusion temperature of the joint portion was low. FIG. 3 (d) is a photograph of a thermal image of a sample (EPA) having a bonding failure on both sides of the bonding portion.
As can be seen from these thermal images, according to the method of the present invention, it is possible to detect a damaged portion of the joint portion outdoors when the temperature rises. It should be noted that overfusion and non-integration may be detected by visual inspection, and can be inspected in combination with the method of the present invention.

<Example 2>
In this example, a part of the water-impervious sheet having breakage in the joint portion was used as a sample, and an inspection was performed as to whether or not a defect in the joint portion could be detected indoors by a thermography device.
As a used sample, a water shielding sheet having a thickness of 1.5 mm was cut out so as to include a joint portion, and a 50 cm to 60 cm square was used. HDPE was used as the material of the water shielding sheet.
Similar to the first embodiment, the bonded portions of these samples are heat-welded so as to have a hollow portion 30 as shown in FIG.
As shown in FIG. 1, this inspection is the same as Example 1 in that it is performed by laying a non-woven fabric 11 by spreading pure sand soil 10 outdoors, and laying a sample 12 thereon, but it is not solar radiation, The thermography apparatus 1 was used to measure the temperature distribution on the surface of the sample 12 that was heated by the halogen lamp and the temperature distribution on the surface of the sample 12 that was cooled after the halogen lamp was turned off. The measurement distance was 1 m and the measurement angle was 35 °.
Fig. 4 (a) is a thermal image of this sample immediately after the start of measurement, Fig. 4 (b) is a photograph of a thermal image 5 minutes after the start of measurement, and Fig. 4 (c) is the start of measurement. Then, a photograph of a thermal image after 30 minutes, FIG. 4D shows a photograph of a thermal image after 10 minutes have passed since the halogen lamp was turned off after 30 minutes.
As can be seen from these thermal images, according to the method of the present invention, it is possible to detect a damaged portion of the joint portion indoors when the temperature rises or falls.

<Example 3>
In the present embodiment, a part of the water shielding sheet having a broken joint is used as a sample, and the thermography device 1 is used when the bottom of the sample is uneven on the outdoors, and when the bottom of the sample is wet. In the case where there is a failure, an inspection was performed as to whether or not a failure of the joint could be detected.
The same sample as used in Example 2 was used.
Similar to the first and second embodiments, the joint portions of these samples are heat-welded so as to have a hollow portion 30 as shown in FIG.
The inspection was performed by measuring the temperature distribution on the surface of the sample when the underwater shielding sheet as the sample was not flat with the thermography device 1. The measurement distance was 1 m and the measurement angle was 35 °. I went on a cloudy and sunny day.
FIG. 5 shows a photograph (left figure) of a thermal image immediately after the start of measurement of each sample and a photograph (right figure) of a thermal image 5 minutes after the start of measurement.
FIG. 5A is a photograph of a thermal image of the sample measured on a cloudy day when the sample is not flat, and FIG. 5B is a thermal image of the sample measured on a clear day. It is a photograph of an image. FIG. 5 (c) is a photograph of a thermal image of this sample measured on a cloudy day when the bottom of the sample is wet.
As can be seen from these thermal images, according to the method of the present invention, as in Example 1, the temperature of the water-impervious sheet as a whole is lower than that of the state where the sample is a sandy soil under the water-impervious sheet. Although it does not rise, it is possible to detect the damaged portion of the joint.
Moreover, although the detection of the broken part of a junction part can be detected more clearly when inspecting under a clear sky than inspecting under a cloudy day, the damaged part of the joint part can be detected even under a cloudy day.

<Example 4>
In this example, when the temperature of the water shielding sheet is forcibly changed using a dryer, an inspection is performed as to whether or not the thermographic device can grasp the temperature difference at the joint of the water shielding sheet. It was.
As shown in FIG. 6, the inspection was performed by laying the nonwoven fabric 11 on the ground and forcibly heating (cooling) the water shielding sheet 13 laid on the nonwoven fabric 11 with a dryer 14.

  The first inspection was performed by measuring the temperature distribution of the surface of the inspection location including the joint portion of the water-impervious sheet 13 with the thermography device 1 (air temperature 26 ° C., sheet temperature 28 ° C., joint width 1.5 cm, Inspection hole width 2.0 cm).

FIG. 7 (a) is a photograph of a thermal image showing the initial state of the inspection location before using the dryer 14, and FIG. 7 (b) shows a state where hot air is blown to the inspection location by the dryer 14 for 10 seconds. It is a photograph of the thermal image shown. FIG. 7C is a photograph of a thermal image showing a state in which 10 seconds have passed since the blowing of warm air by the dryer 14 was stopped, and FIG. It is a photograph of the thermal image which shows the state which ventilated for second.
As can be seen from the photographs of these thermal images, as in this embodiment, after the temperature of the water shielding sheet is forcibly raised by a dryer, the thermography is performed by forcibly lowering the temperature. The temperature difference of the water shielding sheet can be grasped more clearly by the device.

In the second inspection, the thermography device 1 measures the temperature distribution of the surface of the inspection portion including the repair patch portion of the water shielding sheet 13 repaired by the repair patch for repairing the damaged portion of the water shielding sheet 13. (Air temperature: 26 ° C., sheet temperature: 28 ° C., repair patch length: 14.6 cm × width: 14.0 cm)
FIG. 8A is a photograph of a thermal image showing an initial state of an inspection location before using the dryer 14, and FIG. 8B is an inspection location immediately after heating by the dryer 14 (0 second). It is the photograph of the thermal image which shows the state of. FIG. 8C is a photograph of a thermal image showing a state in which 30 seconds have passed after heating with the dryer 14. FIG. 8D is a photograph of a thermal image showing a state in which 90 seconds have passed after heating by the dryer 14. FIG. 8 (e) is a photograph of a thermal image showing a state where 180 seconds have passed after heating by the dryer 14. FIG. 8F is a photograph of a thermal image showing a state in which 360 seconds have passed after heating by the dryer 14.
As can be seen from the photographs of these thermal images, after the temperature of the water shielding sheet is forcibly raised by a dryer as in this embodiment, the water is clearly insulated by performing an inspection while lowering the temperature. The temperature difference of the sheet can be grasped.

<Example 5>
In this embodiment, as shown in FIG. 9, the pure sand 15 is raised outdoors so as to have a cylindrical shape having a depression 15 a at the approximate center, and the sheet material 16 is stacked so as to cover the pure sand 15. When a sample is used as a sample and the temperature of the sheet material 16 is forcibly changed using a halogen lamp 17 as shown in FIG. 10, can the presence of the depression 15a be detected by the temperature difference? If the temperature of the laid sheet material 16 is forcibly changed using the halogen lamp 17 by performing an inspection of whether or not, a portion of the sheet material 16 that is depressed on the back base can be detected. A check was made for no.
FIG. 11A is a photograph of a thermal image showing an initial state of the sheet material 16 before irradiating light from the halogen lamp 17, and FIG. 11B is after starting irradiation of light from the halogen lamp 17. 2 is a photograph of a thermal image showing the sheet material 16 of FIG.
As can be seen from the photographs of these thermal images, the temperature in the vicinity of the depression 15a, which is a non-land portion, is slightly high even before the light from the halogen lamp 17 is irradiated. The difference becomes more prominent. For this reason, if the temperature of the laid sheet material 16 is forcibly changed using the halogen lamp 17, a portion of the sheet material 16 that is depressed on the back base can be detected.

<Example 6>
In this embodiment, as shown in FIG. 12, when hot air is passed through the hollow portion 30 of the water-impervious sheet 13 to forcibly change the temperature of the joint, the joint is damaged due to the temperature difference. An examination was made to see if there was any.
The inspection is performed by sending warm air through the tube 18a from the exhaust port of the vacuum pump 18 into the hollow portion 30 of the water-impervious sheet 13 laid on the ground, and passing the hollow portion 30 through the tube 18a. The temperature distribution of the surface of the inspection location including the joint was measured with the thermography apparatus 1.

  The first inspection was performed using a water-impervious sheet having breakage at a predetermined portion of the joint portion on one side of the hollow portion.

  FIG. 13A is a photograph of a thermal image showing the initial state of the inspection location before the warm air is sent, and FIG. 13B is a diagram showing a case where the warm air is sent into the cavity 30 by the vacuum pump 18 for 3 seconds. It is the photograph of the thermal image which shows the state which passed. FIG. 13C is a photograph of a thermal image showing a state in which 6 seconds have passed since the hot air was sent into the cavity portion 30 by the vacuum pump 18. FIG. 13D is a photograph of a thermal image showing a state in which 9 seconds have passed since the warm air was sent into the hollow portion 30 by the vacuum pump 18. FIG. 13E is a photograph of a thermal image showing a state where 12 seconds have passed since the warm air was sent into the cavity portion 30 by the vacuum pump 18. FIG. 13 (f) is a photograph of a thermal image showing a state where 15 seconds have passed since the warm air was sent into the hollow portion 30 by the vacuum pump 18. FIG. 13G is a photograph of a thermal image showing a state where 18 seconds have passed since the warm air was sent into the hollow portion 30 by the vacuum pump 18.

  The second inspection was performed using a water shielding sheet having breakage at a predetermined portion of the joint portion on both sides of the hollow portion 30.

  FIG. 14A is a photograph of a thermal image showing an initial state of the inspection location before the hot air is sent, and FIG. 14B shows the case where the hot pump is sent into the cavity 30 by the vacuum pump 18 for 3 seconds. It is the photograph of the thermal image which shows the state which passed. FIG. 14 (c) is a photograph of a thermal image showing a state in which 6 seconds have passed since the warm air was sent into the hollow portion 30 by the vacuum pump 18. FIG. 14D is a photograph of a thermal image showing a state in which 9 seconds have passed since the warm air was sent into the hollow portion 30 by the vacuum pump 18. FIG. 14E is a photograph of a thermal image showing a state where 12 seconds have passed since the hot air was sent into the hollow portion 30 by the vacuum pump 18. FIG. 14 (f) is a photograph of a thermal image showing a state where 15 seconds have passed since the warm air was sent into the hollow portion 30 by the vacuum pump 18. FIG. 14 (g) is a photograph of a thermal image showing a state where 18 seconds have passed since the warm air was sent into the hollow portion 30 by the vacuum pump 18.

As can be seen from the photographs of the thermal images in FIG. 13 and FIG. 14 above, the temperature of the damaged part is clearly different from the other parts, and the flow of the hot air blown out from the damaged part to the outside of the joint can be confirmed. .
That is, as in the present embodiment, by passing hot air through the hollow portion 30 of the water-impervious sheet 13 and forcibly changing the temperature of the hollow portion 30, the thermographic device 1 clearly displays the water-impervious sheet 13. The temperature difference can be grasped.
In this way, if the joint is imaged in a state where the warm air is passed through the hollow portion 30 of the water-impervious sheet 13 and the temperature of the joint is changed, the specific position where the breakage occurs is specified. Can do. Moreover, since the sent warm air passes through the hollow portion, it does not pressurize the joint and does not damage the water shielding sheet. In addition, this method is less time-consuming and accurate than heating with a dryer or the like.
In addition, although the case where warm air was sent in the present Example was described, it is not restricted to this, You may send cold air in a cavity part. Moreover, although the case where the vacuum pump 18 was used was described in the present embodiment, the present invention is not limited to this. For example, any device may be used as long as it can send warm air or cold air into the cavity, such as a blower. The inspection of the breakage point of the water-impervious sheet may be performed with the temperature of the joint part changed, and it may be performed while hot air or cold air is sent into the cavity, or the supply of hot air or cold air is stopped. It may be done later.

[Second Embodiment]
The method for inspecting a damaged portion of the water shielding sheet in the present embodiment is performed while moving the thermographic apparatus.
That is, as shown in FIG. 15, when the nonwoven fabric 11 is laid on the concave surface where the waste is buried, and the water shielding sheet 13 is laid on the nonwoven fabric 11, the thermography apparatus 1 can capture the water shielding sheet 13. Using the mounted movable carriage 21 with wheels, the joint portion of the water shielding sheet 13 is continuously imaged along the length direction of the joint portion.
Imaging is performed by moving the movable carriage 21 on the rubber guide rail 20 laid on the water shielding sheet 13.
The guide rail 20 is provided with irregularities at regular intervals in the vertical direction, whereas the wheels 22a and 22b of the movable carriage 21 are provided with irregularities at regular intervals. It is designed to engage with unevenness.
A wire 24 connected to the winch 23 fixed to the shoulder side is attached to the wheel 22a on the shoulder side of the movable carriage 21, and by adjusting the length of the wire 24 with the winch 23, The movable carriage 21 can be run.
In addition, a dryer 27 is mounted on the movable carriage 21 so that the thermographic device 1 is sandwiched so that the air blows against the water shielding sheet 13.
The movable carriage 21 is made to travel on the joint portion of the water-impervious sheet 13 from the shoulder to the tail, and the water-impervious sheet 13 is heated or cooled by the dryer 27 while the water-impervious sheet 13 is heated or cooled. The part is imaged. In addition, the image of the imaging location can be confirmed by the liquid crystal monitor 25 installed on the shoulder side. The liquid crystal monitor 25 is connected to the thermographic apparatus 1 by a cable 26.
If such a movable carriage 21 is used to image the joint portion while moving the thermography apparatus 1, a continuous thermal image of the joint portion to be inspected can be obtained, and labor for inspecting the damaged portion of the joint portion. Can be further reduced.

The figure which shows the state which test | inspects the damage location of a junction part with a thermography apparatus by the test | inspection method of this invention. The figure which shows the photograph of the thermal image of the sample (HDPE) with a joining defect on both sides of a junction part. The figure which shows the photograph of the thermal image of the sample which has a failure | damage in the junction part of each sample. The figure which shows the photograph of the thermal image of the sample which has a failure | damage in a junction part. The figure which shows the photograph of the thermal image of the sample which has a failure | damage in a junction part. The figure which shows the state which test | inspects the damage location of a junction part with a thermography apparatus, forcibly changing the temperature of a water shielding sheet using a dryer. The figure which shows the photograph of the thermal image at the time of blowing warm air with a dryer to a sample. The figure which shows the photograph of the thermal image at the time of blowing warm air with a dryer to a sample. The figure which shows the state which piled up pure sand soil so that it might become a cylinder shape which has a depression part in the approximate center, and accumulated the sheet material so that this true sand soil might be covered. The figure which shows the state which test | inspects that there is a depression part with a thermography apparatus, forcibly changing the temperature of a sample using a halogen lamp. The figure which shows the photograph of the thermal image at the time of irradiating light to a sample with a halogen lamp. The figure which shows the state which test | inspects a damage location with a thermography apparatus, passing a hot air or a cold wind in a cavity part. The figure which shows the photograph of the thermal image at the time of letting warm air or cold air pass in a cavity part. The figure which shows the photograph of the thermal image at the time of letting warm air or cold air pass in a cavity part. The figure which shows the state which test | inspects the damage location of the junction part of the laid water-impervious sheet, moving a thermography apparatus. The figure which shows the joining state of adjacent sheet | seat materials. The figure which shows the joining state of adjacent sheet | seat materials.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermography apparatus 2,16 Sheet material 10,15 Pure sand 11 Nonwoven fabric 12 Sample 13 Water shielding sheet 14,27 Dryer 15a Depressed part 17 Halogen lamp 18 Vacuum pump 20 Guide rail 21 Movable carriage 22a, b Wheel 23 Winch 24 Wire 25 LCD monitor 26 Cable 30 Cavity 40 Resin

Claims (2)

Is intended to be laid on the concave surface of waste landfills, the leachate generated from waste the is concave as leakage to prevent from, shielding plurality heat welded sheet material aqueous was given It is an inspection method for inspecting a damaged portion of a joint portion which is a portion to which the sheet material of the water shielding sheet constituted by joining is joined ,
Among the water shield sheet, seen including a process of imaging by thermography temperature distribution of the surface of the portion to be inspected,
The imaging of the temperature distribution on the surface of the water-impervious sheet is performed when the entire temperature of the water-impervious sheet is not uniform because a high temperature due to heat welding remains in the joint.
Inspection method for inspecting damaged parts of the water shielding sheet. The inspection of the damaged portion of the water shielding sheet is performed while moving the thermography.
An inspection method for inspecting a damaged portion of the water shielding sheet according to claim 1 .

Images