JP2010101003A - Method for checking pressure receiving slab - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively check the presence/absence of rupture in a portion connected to a brace material by a simple method without destroying a pressure receiving slab. <P>SOLUTION: A temperature changing means for forcibly heating or cooling the pressure receiving slab, and a temperature-distribution measuring means for measuring the distribution of the temperature of the surface of the pressure receiving slab are used. A single pressure receiving slab or a plurality of them are forcibly heated or cooled from the outside by the temperature changing means, and then, the presence/absence of the rupture in the connected portion is checked on the basis of the temperature distribution of the surface of the pressure receiving slab which is measured by the temperature/distribution measuring means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pressure receiving plate inspection method for detecting non-destructively the presence or absence of breakage in a connecting portion in which a backing material is connected to the back surface (back surface) of a pressure receiving plate having a planar shape such as a retaining wall.

  For example, a method of stabilizing the slope by burying these backing materials in the ground on the back side of the pressure plate while connecting back materials such as steel and polymer to the back side of the pressure plate of various materials. It has been widely known for a long time, and its construction results are also abundant (Patent Documents 1 to 3).

Japanese Patent Publication No. 44-25174 Japanese Examined Patent Publication No. 4-49609 JP 2000-8377 A

Recently, there have been reports of cases in which a part of the pressure-receiving plate constructed by this type of method is deformed or the connection part of the retaining material is suspected to be damaged. There is a risk of triggering.
(1) In order to avoid such a situation, a method is adopted in which the pressure receiving plate is broken like a sample to check the state of the connecting portion with the backing material.
However, this sampling method not only has the problem of high cost and poor workability, but also takes time to restore after removing the pressure receiving plate, and is not practical when the investigation range is wide.
(2) As another method for confirming the state of the connecting portion with the backing material without destroying the pressure receiving plate, a method using electromagnetic waves, X-rays, etc. can be considered, but the inspection equipment is expensive and the inspection is performed. Professional qualifications and expertise are required to do so.
(3) Because of the above, there is no suitable investigation method for the existing pressure plate, and a proposal for a technology that can accurately and efficiently investigate the current state of the connection with the backing material on the back of the pressure plate Is anxious.

The present invention has been made in view of the above points, and an object of the present invention is to provide at least one pressure-sensitive plate inspection technique.
(1) The presence or absence of breakage of the connecting portion with the backing material can be investigated at a low cost by a simple method without destroying the pressure receiving plate.
(2) The survey results can be surveyed in a short time and the survey results are highly reliable.
(3) Do not require professional qualifications for the survey.

1st invention of this application is the investigation method of the pressure receiving plate which detects the presence or absence of the fracture | rupture in the connection part which connected the backing material to the back surface of the pressure receiving plate which covers the side surface of a soil structure by nondestructive, Comprising: And a temperature distribution measuring means for measuring the temperature distribution on the surface of the pressure receiving plate, and forcing one or more pressure receiving plates from the outside by the temperature changing means. After heating or cooling, the presence or absence of breakage of the connecting portion is investigated based on the temperature distribution of the pressure receiving plate measured by the temperature distribution measuring means.
A second invention of the present application is the vibration according to the first invention, wherein the temperature changing means is vibration by a vibrator capable of traveling on the earth structure so as to transmit stress to the connecting portion between the pressure receiving plate and the retaining material. It is characterized by.
A third invention of the present application is a load applied by a heavy object placed on the earth structure so that the temperature changing means transmits stress to the connecting portion between the pressure receiving plate and the holding material in the first invention. It is characterized by this.
According to a fourth invention of the present application, in the first invention, the temperature changing means is a heating material that directly heats the surface of the pressure receiving plate, and heats the connecting portion with the recording material from the surface of the pressure receiving plate. It is a feature.
A fifth invention of the present application is characterized in that, in the first invention, the temperature changing means is a cold insulating material that directly cools the surface of the pressure receiving plate, and cools the connecting portion with the recording material from the surface of the pressure receiving plate. Is.
A sixth invention of the present application is any one of the first to fifth inventions, wherein the temperature distribution measuring means is a contact type or a non-contact type thermography, temperature sensor, or thermal sheet capable of measuring a temperature change. It is characterized by being one.

The present invention has the following remarkable effects.
(1) Since it is possible to investigate the presence or absence of breakage of the connecting portion with the backing material on the back of the pressure receiving plate from the temperature distribution of the pressure receiving plate, it is possible to investigate a relatively large area at a low cost without destroying the pressure receiving plate. .
(2) Even if there is no specialized knowledge, it is possible to investigate accurately in a short time.
(3) When a plurality of retentive materials are connected to the back surface of one pressure receiving plate, it is also possible to specify the breaking position of the connecting portion.
(4) Since the presence or absence of breakage of the connecting portion between the pressure receiving plate and the holding material can be investigated from a very slight temperature change, not only the temperature change cost is low, but there is no fear of altering the pressure receiving plate.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(1) Premise of invention FIG. 1 shows a model diagram of the investigation method of the present invention.
In the figure, reference numeral 1 is a soil structure, 2 is a plurality of pressure receiving plates that cover the side surfaces of the earth structure 1, 3 is a pad that is embedded in the earth structure 1, and one end of which is connected to the pressure receiving plate 2 It is a material.
In this example, the side surface of the soil structure 1 is covered with a single pressure receiving plate 2, but a plurality of pressure receiving plates 2 may be arranged in the vertical and horizontal directions, and there is no particular limitation on the covering form. .

The pressure receiving plate 2 premised on the present invention is a known block body made of a material capable of conducting heat, such as concrete or resin, and there is no restriction on its cross-sectional shape, planar shape, surface shape and the like.
On the back surface of the pressure receiving plate 2, a known connecting element for connecting the retainer 3 directly or indirectly is provided.
The retentive material 3 on which the present invention is based includes a plate, a band, a string, a net, and a rod made of a metal or polymer material having excellent tensile strength.
The connecting means of the backing material 3 and the pressure receiving plate 2 includes a form in which one end of the backing material 2 is directly connected to a connecting element on the back surface of the pressure receiving plate 1, one end of the backing material 2, and a connecting element on the back surface of the pressure receiving plate 1. There is a form in which the connecting material is indirectly connected between the two.

The former form is a form in which one end of the retentive material 3 is connected to a hole provided on the back surface of the pressure receiving plate 2 or a connecting element that can be hooked by insertion binding or pin connection.
As the latter form, a connecting member such as a belt member or a connecting ring is provided between a connecting element such as a hole or a hook provided on the back surface of the pressure receiving plate 2 and an opening element formed at one end of the holding member 3. Are connected.

(2) Measurement principle The present invention is a method for investigating the presence or absence of breakage in the connecting portion 4 between the pressure receiving plate 2 and the backing material 3 without destroying the pressure receiving plate 2 (non-destructive). A temperature changing means for temperature or cooling and a temperature distribution measuring means 5 for measuring the temperature distribution on the surface of the pressure receiving plate 2 are provided.

After forcibly heating or cooling one or a plurality of pressure receiving plates 2 from the outside by the temperature changing means, the temperature distribution measuring means 5 measures the temperature distribution change of the surface of the pressure receiving plate 2, and the temperature distribution Based on the change, the presence or absence of breakage of the connecting portion 4 is investigated.
In particular, the present invention pays attention to the difference in thermal conductivity between a normal part (a connected state) and an abnormal part (a broken state or a state close to a broken state) of the connecting portion 4 in which the backing material 3 is connected to the back surface of the pressure receiving plate 2. It was made as a result.

(3) Temperature changing means As means for forcibly changing the temperature (heating or cooling) of the pressure-receiving plate 1, the following method can be adopted.

(3-1) Heating

[A] A method of applying an external force to the holding material 2 by forcibly vibrating from the upper part of the earth structure 1 or by loading a heavy object W on the upper part of the earth structure 1.
In the former method, for example, an external force can be applied to the retentive material 2 by causing a vibration roller used for pavement to run on the upper surface of the earth structure 1.
In the latter method, for example, by applying a static load such as embankment on the top of the earth structure 1, it is possible to apply an external force to the material 2.
In the two exemplary embodiments described above, when the earth pressure of the structure 1 increases due to vibration or loading, the tensile stress of the retainer 2 increases, and the tensile stress of the retainer 2 increases. The connecting part 4 generates heat and the temperature rises.
The above-described exothermic action is known from various papers and literatures.

[B] A method in which the surface of the pressure receiving plate 1 is uniformly heated over a certain period of time by a heating means, and the connected recording material 3 is heated.
As the heat generating means, it is possible to use a known heat generating material or heat storage material.

(3-2) Forced cooling

[A] A method in which the surface of the pressure-receiving plate 1 is uniformly cooled over a certain period of time by a cooling means to cool the connected holding members 3.
As the cooling means, for example, a known cold insulating material can be used.

(4) Temperature Distribution Measuring Unit As the temperature distribution measuring unit 5, a device capable of measuring a temperature change in a non-contact manner such as a thermography (infrared thermography), a temperature sensor, a heat sensitive sheet, or the like can be used.
Infrared thermography can use a cheap commercial item.
The temperature sensor includes a contact type provided on the surface of the pressure receiving plate 2 and a non-contact type provided separately from the surface of the pressure receiving plate 2.
Commercial products can also be used as the heat sensitive sheet.

[Investigation method]
Next, the investigation method will be described.

(1) Forced heating (or forced cooling)
The recording material 3 is forcibly heated (or forcibly cooled) by the temperature changing means described above and left.
If the connecting part 4 between the forcibly heated (or forcedly cooled) material 3 and the pressure receiving plate 2 is in a normal state without breakage, the temperature of the connection part 4 rises uniformly (or is cooled), and the breakage is abnormal. If it is in a state, the amount of change of the temperature of the connecting portion 4 differs with respect to the temperature change of other locations.

(2) Measurement of pressure plate surface temperature If forced heating (or forced cooling) is allowed to stand, there will be a difference in the generated temperature between when the connecting part 4 is normal and when it is abnormal, and this temperature difference (temperature distribution) ) Is directly transmitted to the surface of the pressure receiving plate 2 having thermal conductivity.
Next, the temperature change is measured by the temperature distribution measuring means 5 from the surface side of the pressure receiving plate 2.
As described above, since the surface temperature of the pressure receiving plate 2 is based on the temperature change of the connecting portion 4, the temperature distribution measuring means 5 indirectly measures the temperature change of the connecting portion 4 of the backing material 3 and the pressure receiving plate 2. Will be measured.
Based on the distribution of the temperature change (temperature drop change or temperature rise change) measured in this manner, the presence or absence of a broken portion of the connecting portion 4 is determined and specified as a broken portion.
As a method for identifying the fracture location, the location where the temperature change was not observed compared to other sites based on the distribution of the measured temperature change was identified as the fracture location, or from the difference in temperature change with other connecting parts. It can be specified as a fracture location.
Further, the measurement range by the temperature distribution measuring means 5 means a range in which the connecting portions 4 of the plurality of holding members 3 can be measured at a time, and the pressure receiving plate 1 is not limited to a single sheet, but a plurality of pressure receiving pressures. It is also possible to measure the plate 1 at a time.

[Other embodiments]
In the above embodiment, when the pressure receiving plate 2 is forcibly heated or cooled, paying attention to the fact that the thermal conductivity is different, not the temperature change, the speed until the predetermined set temperature is reached. It is desirable to measure.
In the case of forced heating, the cooling rate is measured, and in the case of forced cooling, the return rate to room temperature is measured.

  When the soil structure 1 is embankment, a compacting machine 6 (self-propelled vibrating roller) is used as the temperature changing means, and an infrared thermography camera is used as the temperature distribution measuring means 5.

The compacting machine 6 is reciprocated at the top end of the earth structure 1 to give increased stress and / or vibration to the embankment, and these stresses are transmitted to the backing material 3.
When one end of the retainer 3 is connected to the pressure receiving plate 2, the stress transmitted to the retainer 3 through the embankment acts on the connecting portion 4 in a concentrated manner (FIG. 2).

  As a result, the connecting portion 4 between the retainer 3 and the pressure receiving plate 2 is caused to generate heat, and the generated heat is transmitted to the pressure receiving plate 2.

  When one end of the backing material 3 is not connected to the pressure receiving plate 2, the stress transmitted to the backing material 3 through the embankment does not act on the connecting portion 4. (Figure 3).

The temperature change generated in the connecting portion 4 of the backing material 3 connected to the pressure receiving plate 2 is captured imagewise by photographing the surface temperature of the pressure receiving plate 2 with an infrared thermography camera.
From the image data of the surface temperature of the pressure receiving plate 2, it is possible to detect whether or not the pressure receiving plate 2 and the retentive material 3 are connected by visually observing the presence or absence of reaction and the difference in temperature.
In particular, since the infrared thermography camera can display a minute temperature change as a difference in coloring, the state of the connecting portion 4 can be accurately grasped without specialized knowledge.

  Since the above survey work can be performed at a plurality of locations, it is possible to easily survey even if the survey range is wide.

Model diagram of survey method according to the present invention Model diagram when the connection between pressure plate and backing material is normal Model diagram when the connection between pressure plate and backing material is abnormal

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Soil structure 2 ... Pressure receiving plate 3 ... Retaining material 4 ... Connection part

Claims (6)

A method for investigating a pressure-receiving plate that detects non-destructively the presence or absence of breakage in a connecting portion in which a backing material is connected to the back surface of the pressure-receiving plate that covers the side of the soil structure,
A temperature changing means for forcibly heating or cooling the pressure receiving plate;
Use the temperature distribution measuring means to measure the temperature distribution on the surface of the pressure plate,
One or more pressure receiving plates are forcibly heated or cooled from the outside by the temperature changing means,
Then, based on the temperature distribution of the pressure plate measured by the temperature distribution measuring means, to investigate the presence or absence of breakage of the connecting portion,
Survey method for pressure-sensitive plates.   2. The pressure receiving plate according to claim 1, wherein the temperature changing means is vibration by a vibrator capable of traveling on the earth structure so as to transmit stress to a connection portion between the pressure receiving plate and the retaining material. Survey method.   2. The pressure receiving plate according to claim 1, wherein the temperature changing means is a load applied by a heavy object placed on the earth structure so as to transmit stress to a connecting portion between the pressure receiving plate and the holding member. Survey method.   The investigation of the pressure receiving plate according to claim 1, wherein the temperature changing means is a heating material that directly heats the surface of the pressure receiving plate, and heats the connecting portion with the backing material from the surface of the pressure receiving plate. Method.   2. The method for examining a pressure receiving plate according to claim 1, wherein the temperature changing means is a cold insulating material that directly cools the surface of the pressure receiving plate, and cools the connecting portion with the backing material from the surface of the pressure receiving plate.   6. The temperature distribution measuring means according to claim 1, wherein the temperature distribution measuring means is any one of a thermography, a temperature sensor, and a thermal sheet capable of measuring a temperature change by a contact type or a non-contact type. And the pressure-sensitive version survey method.

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