JPH1082750A - Method and apparatus for diagnosing deterioration of sprayed slope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly judge the characteristic of the back of an existing sprayed slope to properly evaluate stability of the sprayed slope. SOLUTION: Thermal images at two time points such as a rank in relative temperature differences due to daytime solar radiation and a rank in relative temperature differences during night time among respective sites on a sprayed slope 11 for protecting a ground 10 are set side by side, and a site indicating a high or low temperature as a specific temperature change is extracted while comparing the two. Moreover, facts on a rear of the sprayed slope 11 is checked and inspected by drilling or the like to determine whether the site indicating the specific temperature change is a cavity 20, a soil 21, a normal part 22 or a humid part 23 from a temperature change pattern. This method provides sufficient inspection accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for diagnosing aging of a sprayed slope for accurately evaluating the stability of an existing sprayed slope and extracting weak points due to aging and the like. It concerns the device.

[0002]

2. Description of the Related Art A sprayed slope is a slope that is sprayed with mortar or concrete for the purpose of preventing the slope of a cut ground from weathering. By spraying the slope, the weathering of the internal ground proceeds. Can be suppressed to the limit. Since the spray mortar itself does not have a mechanical slope reinforcing effect, the mortar is sprayed immediately after cutting with a stable gradient.

[0003] Such a sprayer, unlike other concrete structures, has the following characteristics. Since mortar and concrete are sprayed directly on the slope, no formwork is required. The mechanical equipment is simple, and wide and steep slopes can be easily and quickly constructed. Due to the low construction cost, 8 million m ² is newly constructed every year.

[0004] Spraying is an effective method as described above, but has the following problems. Large structure with large surface area. In addition, there are many irregularities on the slope, and it is not possible to control spraying with a constant thickness. Furthermore, since curing is performed in a natural state, phenomena such as cracking and peeling are likely to occur. Durability greatly depends on construction conditions and weather conditions. Once the ground has been covered with mortar, the degree of weathering over a long period of time cannot be easily known from the outside, and inspection cannot be performed except for phenomena such as cracking and peeling, and there is a problem in maintenance.

Aging due to weathering of the ground is roughly classified into the following six as shown in FIG. a. Collapse of mortar due to deterioration of mortar itself b. Collapse of mortar due to poor adhesion between ground and mortar c. Failure of the slope itself due to sedimentation of the ground layer d. Rock fall due to falling off of rock on the back of mortar e. Deep collapse of the slope itself due to deep crush zones, etc. f. Peeling type rock fall by joint and bedding

Conventionally, the above-mentioned inspection work of the sprayed slope has been limited to visual inspection only from the external appearance, and there has been no aging diagnosis technology having relatively high accuracy in a short time. It is difficult to grasp the spraying inside situation,
There were problems such as a huge number of target locations and the need to work at high altitudes. Therefore, there has been a need to establish a method capable of performing an effective inspection without destroying the sprayed mortar.

[0007] As a method of searching for a defect on a machined ground such as a slope, an inner surface of a tunnel, and a road surface, there is a method using thermal infrared rays (Japanese Patent Publication No. 2-20941). This is based on the phenomenon that the larger the crack on the road surface and the deeper the crack, the greater the difference in the ground temperature and the larger the temperature difference occurs, and the infrared detector is mounted on a vehicle such as a vehicle and processed. The ground is scanned, thermal infrared rays are sequentially received by an infrared detector, and the output change is monitored as an image pattern as shown in FIG.

[0008]

The conventional method shown in FIG. 10 only scans the ground to be processed, detects only one time difference in temperature due to thermal infrared rays, and monitors the output change as an image pattern. Therefore, there was a problem that sufficient exploration accuracy could not be obtained. In other words, the temperature difference between the parts on the sprayed slope varies depending on the measurement conditions such as daytime and nighttime, fine weather and cloudy or rainy, and the search accuracy is insufficient. In addition, it was not possible to distinguish the structure of the back surface of the sprayed slope, such as whether it was a hollow portion, a sediment portion, a healthy portion, or a wet portion, only from the temperature difference.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and an apparatus for accurately determining the properties of the rear surface of an existing spraying slope and accurately evaluating the stability of the spraying slope.

[0010]

According to the present invention, the order of the relative temperature difference between the respective parts of the protective spraying slope 11 of the ground 10 due to the insolation during the daytime and the order of the relative temperature difference at night is shown. And the reversal of the relative temperature relationship between the morning and the evening, and a fact-finding survey of the back surface of the sprayed slope 11 by drilling or the like is performed, and the sprayed slope 1
This is a method for diagnosing the aging of a sprayed slope in which it is determined whether the back property 1 is a hollow portion 20, a soil portion 21, a healthy portion 22, or a wet portion 23.

The interpretation of the thermal image and the arrangement of the results are performed in the following procedure after the measurement. (1) The positional relationship between the thermal image and the spray surface 11 is confirmed. (2) By arranging the thermal images at two times, a part showing a high or low temperature as a unique temperature change is extracted while comparing the thermal images with each other. Subsequently, a meaning is given to a part showing a unique temperature change from the temperature change pattern. (3) Based on the deformed portion read from the thermal image and the result of the visual inspection, a thermal image interpretation drawing is created. For example, in the front view of the sprayed slope 11, the items of the visual inspection are described,
Cavity part 20, earth and sand part 21, healthy part 2 read from thermal image
2. Fill in the wet part 23.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG.
1 is warmed by solar radiation during the day and cooled by outside air at night. Externally affected spraying surface 1
1 is caused by a difference in heat transfer due to a difference in specific heat and a difference in thermal conductivity, such as deformation of ground 10, spring water, thickness of spraying mortar 19, and some differences depending on properties of ground 10 behind spraying slope 11. It appears as a surface temperature distribution with regularity. The present invention detects the surface temperature of the sprayed slope 11 by thermal infrared imaging, and estimates the properties of the ground 10 behind the sprayed slope 11 in accordance with the regularity of the relative surface temperature. An aging diagnosis method and its device.

First, a general thermal infrared imaging method will be described. There are three forms of heat transfer: heat conduction, convection, and radiation. Due to these forms of heat transfer, the material constantly changes in temperature and has various characteristics.

A basic system of thermal infrared imaging employed in the present invention will be described with reference to FIG. The detector 12 composed of an infrared camera is used for the spray surface 11 which is the object to be inspected.
Control unit 1 detects thermal infrared energy radiated from
The image is displayed and displayed on the display unit 14 via the display unit 3. The imaged temperature information is stored in the image processing / analysis device 17.
Such information is processed by peripheral devices such as a floppy disk, and recorded, stored, and managed in an image recording device 15 such as a floppy disk or an image output device 16 such as a VTR printer.

The main features of this thermal infrared imaging method are as follows. The temperature of the measurement object can be measured without contact. Since the image is displayed in a state of being visualized as a temperature distribution, two-dimensional observation is easy. Observation in the dark is possible. It has a fast response speed and can observe moving objects. Recording and management of temperature information can be easily performed.

FIG. 2A shows (1) the surface temperature during the day, (2) the surface temperature during the night, and (3) the temperature change throughout the day when the thermal infrared imaging method is applied to the sprayed slope 11. (B), FIG. 3 (a) (b), FIG. 4 (a)
This will be described with reference to FIG.

(1) Daytime Surface Temperature As shown in FIG. 2 (a), the spray surface 11 is affected by the sunshine during the daytime. The solar energy is partially reflected on the surface of the spray surface 11 and partially absorbed. The heat absorbed by the spray mortar 19 is
It moves to the ground 10 due to the temperature gradient. At this time, if the hollow portion 20 and the wet portion 23 are present behind the spraying surface 11, a change in heat transfer occurs, resulting in a difference in surface temperature. The air layer in the cavity 20 has a small heat conductivity and a small heat capacity. For this reason, when the hollow portion 20 exists behind, the amount of heat transferred to the ground 10 by the solar radiation is hindered by the air layer, and the temperature of the surface of the sprayed mortar 19 becomes higher than that of the sound portion 22.

On the other hand, water has the characteristic of having a large heat capacity. For this reason, the wet portion 2 behind the spray surface 11
3 and the layer of water, the transfer of heat to the ground 10 is promoted, and the spray mortar 19
The surface temperature is lower. Similarly, it is considered that there is a similar tendency depending on the air and the water content, such as the soil portion 21 and the solidified rock.

The heat transfer due to daytime solar radiation on the spray surface 11 is shown in FIG. 2 (b). When the surface temperature is particularly high, the back property is the hollow portion 20 and the thermal conductivity is low. Especially small and heat capacity is small. Further, when the surface temperature is high, the back property is the earth and sand portion 21, the thermal conductivity is small, and the heat capacity is slightly small. When the surface temperature is low, the back property is the healthy portion 22, the heat conductivity is medium, and the heat capacity is medium. When the surface temperature is particularly low, the back property is the wet portion 23, and the thermal conductivity is particularly large. In addition, when the groundwater temperature is relatively high in winter, the temperature of the nighttime wet portion 23 may be high.

(2) Surface Temperature at Night The thermal energy stored on the spraying slope 11 is as shown in FIG.
As shown in (a), at night, the air is radiated from the surface of the sprayed mortar 19 into the air as the temperature decreases. As a result, the temperature of the surface of the spray mortar 19 gradually decreases. Even in such a cooling process, when the hollow portion 20 and the wet portion 23 are behind the blowing surface 11, a difference in heat transfer occurs due to a difference in accumulated heat amount, a difference in heat conductivity, and a difference in specific heat.

That is, since the supply of heat from the ground 10 is cut off in the portion where the hollow portion 20 exists behind the spray surface 11, the surface temperature drops sharply as compared with the sound portion 22. Show the trend. On the other hand, spraying slope 1
In the portion where the wet portion 23 is located behind 1, the temperature does not easily drop because of the large heat capacity.

The heat transfer due to the nighttime radiation on the spraying surface 11 is shown in FIG. 3B. When the surface temperature is low, the back property is the hollow portion 20 and the heat conductivity is particularly small. , Heat capacity is also small. On the other hand, when the surface temperature is low, the back property is the earth and sand portion 21 and the thermal conductivity is small.
Heat capacity is rather small. When the surface temperature is high, the back property is the healthy portion 22, the heat conductivity is medium, and the heat capacity is medium. When the surface temperature is particularly low, the back property is the wet portion 23, and the thermal conductivity is particularly large. In addition, when the groundwater temperature is relatively high in winter, the temperature of the nighttime wet portion 23 may be high.

(3) Temperature change throughout the day The change in the surface temperature of the spray slope 11 throughout the day is as follows:
It shows a substantially constant cycle in which it is warmed by solar radiation during the day and radiates accumulated thermal energy to cool it down at night. In this cycle, the heat absorption rate and the emissivity are different depending on the properties of the ground 10, and the temperature change is different. FIG.
(A) shows the properties of the ground 10 on the spraying slope 11 divided into the following four states, and the spraying slope 1 with time.
The example which measured one temperature is shown. I. Cavity portion 20: A portion in which the backside of spray slope 11 is hollowed out due to weathering erosion, suction, etc. of ground 10. II. Sediment portion 21: A portion where the weathering of the ground 10 has progressed and the soil has turned into a soil. III. Sound part 22: A part where the ground 10 is integrated with the spray mortar 19 in a sound state IV. Wet part 23: Part where ground 10 is in a state of containing water by spring water

According to the measurement results shown in FIG. 4A, the surface temperature in the daytime is higher in each part than in the nighttime, and changes following the change in air temperature. At this time, the relative temperature after each phase is highest in the hollow part 20 during the day, followed by the earth and sand part 21, the healthy part 22, and the wet part 2
3 is the lowest, and at night, the healthy part 22 is the highest, followed by the earth and sand part 21 and the hollow part 20, and the wet part 23 has the lowest surface temperature. In particular, 9:
At around 00 and around 17:00, a reversal phenomenon occurs in the relative temperature relationship at a portion other than the wet portion 23, and a close relationship is observed between the temperature distribution and the properties of the ground 10. Looking at the change over time in temperature, the cavity 20 is the largest, followed by the earth and sand 21 and the healthy part 22, and the wet part 23 always shows a low temperature.

The above results are organized and the sprayed surface 11
The relationship between the properties of the ground 10 and the surface temperature distribution can be summarized as shown in FIG. 4 (b).
Can be represented by III and IV. That is, I. The temperature of the hollow portion 20 is low in the middle of the night and early in the morning, particularly high in the daytime, and the temperature change between the daytime and the nighttime at two times is particularly large. II. The earth and sand portion 21 has a low temperature in the middle of the night and early in the morning and a high temperature in the daytime, and the temperature change at two hours is large. III. The healthy part 22 has a high temperature in the middle of the night and early in the morning, and has a slightly low temperature in the daytime, and the temperature change at two times is small. IV. The wet portion 23 has a low temperature in the middle of the night and early in the morning (when the groundwater temperature is relatively high, the temperature of the wet portion 23 may be high during the day and at night), and particularly low during the day,
The temperature change at two times is particularly small. Note that grass, trees, moss, and the like block the solar radiation on the sprayed slope 11 and become obstacles for temperature measurement on the surface of the sprayed slope 11. Such obstacles have special temperature characteristics,
Care must be taken when estimating the nature of the ground 10 behind the sprayed slope 11, and it is necessary to remove the sprayed slope 11 within a range that does not adversely affect the slope.

Next, a method and an apparatus for diagnosing deterioration of a sprayed slope according to the present invention by thermal infrared imaging will be described. First, conditions affecting measurement will be described below. (1) Meteorological conditions The weather conditions at the time of measurement are preferably "clear" in principle, but may be "cloudy". "Rain" and "mist" are avoided because moisture may absorb a specific infrared wavelength range, making accurate observation difficult. The measurement time is preferably in summer, but can be measured throughout the year. However, it is not possible to measure when snowing.

(2) Method and Time for Extracting Cavity 20 The cavity 20 has a sharp temperature rise in the morning and a sharp fall in the afternoon as compared to the healthy portion 22. Also,
In the process of ascending and descending, the cavity 20 often causes a temperature inversion phenomenon with the healthy part 22. That is, the hollow portion 20 and the healthy portion 22 can be determined based on the magnitude of the temperature change in each region. For this reason, the measurement is performed at least two times so as to obtain a temperature difference distribution between two times during the day. Usually, two times in the morning, when the sunshine is low, and during the daytime when the solar radiation is maximum are often selected as the shooting time. However, this temperature change has a slight difference depending on the local situation, such as a different start time of the temperature rise depending on the direction of the spraying slope 11 and weather conditions, and it is necessary to appropriately select the measurement time based on the difference. .

(3) Thickness of spraying mortar 19 The thickness limit of the spraying mortar 19 from which the properties on the back side can be inferred from the surface temperature of the spraying mortar 19 is usually 1
It is about 5 cm, and up to about 20 cm if conditions are good. It should be noted that the lower part of the spraying surface 11 tends to increase the thickness of the spraying mortar 19 and may not reflect the back side properties.

(4) Existence of Vegetation Vegetation often exists at the bottom of the sprayed slope 11 and the small step. For this reason, the vegetation becomes an obstacle, and it becomes difficult to measure the surface temperature of the sprayed mortar 19. At the time of measurement, it is necessary to remove as much as possible the effects of vegetation.

(5) Sprayed Slope 11 with Roughness The blown slope 11 for hard rock is a sprayed slope 11 with significantly uneven surface due to difficulty in shaping.
With such a sprayed slope 11, a shadow is generated in the sprayed slope 11 due to the solar radiation angle, and it is not possible to accurately obtain temperature information reflecting the back side. With such a sprayed slope 11, measurement in cloudy weather where shadows do not occur, which is contrary to normal, is suitable.

(6) Peeling of the spray mortar 19 The place where the spray mortar 19 has peeled off is the cavity 2
As in the case of 0, it appears as a region where the temperature change is large. Since the thermal infrared imaging method is based on surface temperature information, it is impossible to detect the presence or absence of the cavity 20 on the back side of the spray mortar 19 at the peeled portion. Visual observation of the surface of the spraying mortar 19
It is necessary to confirm where 9 peeling exists.

(7) Constant Wet Portion 23 In a region where the surface of the mortar 19 sprayed by spring water or drift water is wet, the hollow portion 20 cannot be detected. It is desirable to observe in a dry state according to local conditions.

Next, the equipment required for the investigation of the thermal infrared imaging method and the installation place of the equipment will be described. (1) Thermal infrared imaging device 7 and related equipment used in the present invention The detector 12 composed of an infrared camera has a high response speed,
A quantum detector having high sensitivity is used, and the detection sensitivity desirably corresponds to a wavelength of 8 to 10 μm in consideration of the influence of sunlight radiation. In addition to a cooling cylinder for cooling the element, a generator, a tripod, and the like are required.

(2) Observation equipment Observation of meteorological conditions at the time of measurement, the surface temperature of the sprayed slope 11, the underground temperature, and the like, which are used as a reference for temperature analysis using thermal infrared images. And weather observation equipment such as pyranometers, radiation thermometers for types where temperature information cannot be obtained directly from images, and underground thermometers for measuring underground temperature distribution and time change.

(3) Installation location The installation location of the thermal infrared imaging device 7 is the spray surface 11
It is a very important factor in understanding the temperature distribution on the surface and its change. It is necessary to select an installation location that can obtain the most accurate data as possible. Main installation locations are, for example, as follows. -As shown in Fig. 1, install on flat ground such as roads, riverbanks, and vacant lots. -As shown in FIG. 5A, it is installed on a slope such as a facing slope or an upper slope. -As shown in FIG. 5 (b), it is installed on an aerial work vehicle.・ As shown in Fig. 5 (c), install in the air by helicopter. -As shown in Fig. 5 (d), it is installed on water by a boat, boat, or the like.

A more detailed configuration of the thermal infrared imaging device 7 used in the present invention will be described. (1) Detector 12 The main components of the detector 12 are a scanning unit 24 and an optical unit 2
5, a photoelectric conversion unit 26, a preamplifier 27, and a detection unit control unit 28. The scanning unit 24 is composed of two scanning mirrors, and the infrared light collected by the optical unit 25
At 6, the signal is converted into an electric signal according to the intensity of the infrared light, and sent to the preamplifier 27.

(2) Control Unit 13 The main components of the control unit 13 are an amplifier 29, an A / D conversion unit 3
0, an image memory 31, a D / A converter 32, a color encoder 34, a CPU 35, an I / F 36, an operation panel 37, and the like. The temperature signal from the preamplifier 27 of the detector 12 passes through a correction circuit specific to infrared rays such as environmental temperature correction and emissivity correction in the amplifier 29, and is converted by a linearizer so that the relationship between temperature and output becomes linear. The signal is converted into a digital signal by the A / D converter 30. The A / D converted temperature data is written to the image memory 31. The data in the image memory 31 is read out in a television format together with the character data,
The signal is converted to an analog signal via the conversion unit 32 and displayed on a monitor as a color video signal. The control unit 13
Can be connected to the image output device 16, can transfer image data by connecting to a personal computer, can use various thermal image processing software, and can store image data in the image memory 31 in the image recording device. 15 can be recorded,
The temperature data can be subjected to image processing by the image processing / analysis device 17.

Next, the thermal infrared imaging device 7 as described above
A measurement method using will be described. (1) The thermal infrared imaging device 7 is installed as shown in FIG. 1 or 5 according to the local situation. In addition to the installation of the equipment, a target 38 made of a material having a high reflectance, such as an aluminum plate, is installed at several places on the spray slope 11 to be measured. The target 38 serves as an index when performing correspondence with a visible image, geometric correction such as orthographic transformation, and joining between measurement images.
As for the arrangement, there is an example as shown in FIG.

(1) Mesh method As shown in FIG. 6A, 2 m ×
A method in which the targets 38 are installed at equal intervals (mesh) such as 2 m. Although it takes time and effort, it is also an index when performing visual observation of the sprayed slope 11 and is the most desirable method.

(2) Peripheral method As shown in FIG. 6B, a method of setting a target 38 around the spray surface 11. It is suitable when the boundary between the sprayed slope 11 and the peripheral portion is not clear.

(3) Random Method As shown in FIG. 6 (c), a method of setting the target 38 at some points on the spraying slope 11. It is suitable when you want to specify a characteristic part.

(4) Overlaying Method As shown in FIG. 6D, when a plurality of images of the spraying surface 11 are sequentially overlapped, the spraying surface 11 is relatively overlapped by a method of installing the overlapping images. It is suitable when a large number of images are required.

Next, a thermal infrared image is measured by the thermal infrared image device 7. (1) Observe and record a thermal image by the thermal infrared imaging device 7. The measurement by the thermal infrared imaging device 7 is performed twice or more so that a temperature difference distribution between two times can be obtained. Normally, the morning time when the solar radiation is low and the maximum two times during the day are often selected. However, the measurement time is appropriately selected depending on the direction of the spraying slope 11 and the weather condition.

(2) Visible video or still camera 4
The recording of the surface condition of the spraying slope 11 by 0 is performed. Thereby, not only can the visual condition of the spraying slope 11 be grasped, but also the situation of the spraying slope 11 at a measurement time such as the occurrence or disappearance of a shadow caused by a cloud or a tree can be grasped.

(3) Observation and recording of weather data by the weather data input unit 41. Since the surface temperature of the spray surface 11 is greatly affected by the temperature and the amount of solar radiation, the temperature and the amount of solar radiation are observed at every hour and at the time of thermal image measurement.

(4) If necessary, the spot temperature of several high and low temperature parts around the spray surface 11 is measured by the radiation thermometer 39.

Next, data processing by the thermal infrared imaging device 7 will be described. (1) The video signal from the thermal infrared imaging device 7 is stored in the image recording device 15 as analog data. (2) The controller 13 converts the concentration information into temperature information based on the data obtained by the radiation thermometer 39. (3) The temperature information is digitized by A / D conversion and stored in the image recording device 15 or the like. (4) The image processing / analysis device 17 performs geometric correction and subtraction processing between images.

By analyzing the surface temperature distribution of the sprayed slope 11 and the analysis image showing its change with time by the measurement and data processing as described above, the sprayed slope 11 can be read.
Behind cavity 20, earth and sand 21, sound part 22, wet part 2
A structure such as 3 is estimated. At this stage, an attempt is made to extract a part determined to be abnormal. That is, since the diagnosis of aging by the thermal infrared imaging device 7 is based on indirectly detected data, the final determination of the structure behind the spraying slope 11 and the evaluation of aging are actually made by drilling holes. The results of the supplementary survey (verification survey) process described below, such as surveying, are performed in an integrated manner.

The above-described supplementary survey (verification survey) is performed by the following method. (1) Conduct a verification survey. A typical example of this method is a confirmation check of the back surface of the spray surface 11 performed by piercing using a core cutter or a drill. That is, a perforation is made directly on the spraying surface 11, and observation with an endoscope such as the naked eye or a fiberscope camera is performed. As the survey items in the coring survey, the depth and scale of the cavity 20 and
Investigation of the weathering status of the ground 10 such as confirmation of the moisture condition of the ground 10, the degree and depth of weathering, geology, etc.
Weakening, strength reduction, spray mortar 19 two layers
There is a deterioration state of the spray mortar 19 itself such as the presence or absence of an internal cavity and the presence or absence of a rebound. There are other methods by hammering, but this method is not always reliable.
In the case of piercing, it is quickly restored with mortar or the like.
Since the verification study is performed to obtain data supporting the temperature analysis, it is not necessary to cover all the sites that exhibit abnormal temperatures.

(2) Perform a site survey. The purpose is to grasp and record the deterioration phenomenon of the spraying slope 11, and to grasp the geology and structure of the ground 10, especially the weathering / crushing situation. The items to be described for the deterioration of the sprayed slope 11 are fine cracks, opening cracks, depressions, exposed rocks, white change, moss, fallen leaves, falling rocks,
It is a characteristic item of aging, such as spring water, traces of sediment runoff, spills, and surface peeling. The weathering condition of the ground 10 is observed by observing the sprayed slope 11 and the surrounding ground 10, and features such as the grain size, thickness, and consolidation degree of the weathered product, rock types and joints and crack density of the base material, Describe and record the geological phenomena that cause aging, such as bedding and the presence of shatter zones.

By combining the results of the above temperature analysis and the results obtained by the supplementary survey, the degree of aging of the sprayed slope 11 to be investigated is considered and the necessity of repair is evaluated. The survey results are collected and recorded in a predetermined format.

Although it is possible to interpret the thermal image to some extent even at the time of measurement, a detailed examination requires superposition with a visual inspection result. Therefore, interpretation of the thermal image and arrangement of the results are performed by the following procedure after measurement. (1) The positional relationship between the thermal image and the spray surface 11 is confirmed. In order to facilitate the reading operation of the thermal image, when the spray surface 11 covers a plurality of thermal images, the thermal image is combined with the thermal image, and then the thermal image and the thermal surface are compared by comparing with a visible image such as a photograph. 11 is performed to confirm the positional relationship.

(2) Extract a site showing a unique temperature change. The thermal images of the two times are displayed on a computer display or printed out and arranged side by side, and a part showing a high or low temperature as a unique temperature change is extracted while comparing them with each other. Subsequently, a meaning is given to a portion showing a unique temperature change from a typical temperature change pattern according to the type of deformation as shown in FIG. At this time, if the temperature difference image at two times is created, the deformation range can be easily determined.

(3) Based on the deformed portion read from the thermal image and the result of the visual inspection, a thermal image interpretation drawing is created. For example, as shown in FIG. 8A, in the front view of the sprayed slope 11, as a visual inspection item, the occurrence state of cracks (occurrence site, direction, opening width, presence or absence of a step), peeling of the sprayed mortar 19.・ Washing water, free lime, clogging of drainage holes, discharge of earth and sand, vegetation on the surface of spray slope 11, etc. are described from the state of peeling, drainage holes, cracks, etc. Further, as shown in FIG. 8B, the hollow part 20, the earth and sand part 21, the healthy part 22, and the wet part 2 read from the thermal image
Fill in 3.

It should be noted that although there is no hollow portion 20 or wet portion 23 at the back of the spraying surface 11, a similar pattern may be shown due to other factors. Shade, unevenness of spraying sloping surface 11, water of spraying mortar 19, vegetation on spraying mortar 19, rebound and cavity 2 in spraying mortar 19
0, the thickness of the spray mortar 19 is not uniform.

[0056]

The method according to the present invention detects the surface temperature distribution and the change with time of the spraying slope 11 at the ground 10 and estimates the structure behind the spraying slope 11 from the temperature difference between two times. Because of the relative temperature difference of each part on the spraying slope, the properties behind can be read,
Sufficient search accuracy is obtained. In particular, it can be read whether the back surface of the spraying surface is hollow, earth and sand, sound, or wet.

Further, the temperature of the spray surface 11 can be measured in a non-contact manner, and is displayed in a state of being visualized as a temperature distribution, so that planar observation is easy. Furthermore, the response speed is fast, and recording and management of temperature information can be easily performed.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a method and an apparatus for diagnosing deterioration of a sprayed slope according to the present invention.

FIG. 2A is a cross-sectional view of heat transfer of a spray surface 11 during daytime, and FIG. 2B is an explanatory diagram of FIG.

FIG. 3A is a cross-sectional view of heat transfer of the spraying slope 11 at night, and FIG. 3B is an explanatory diagram of FIG.

FIG. 4 (a) is a characteristic diagram of a temporal change in heat transfer of the sprayed slope 11 over one day, and FIG. 4 (b) is a general pattern of the ground 10 properties and surface temperature behind the sprayed slope 11; FIG.

FIG. 5 is an explanatory view showing a different example of a place where the thermal infrared imaging device 7 is installed.

FIG. 6 is an explanatory diagram showing a different example of a method of setting the target 38;

FIG. 7 is a block diagram of a method and an apparatus for diagnosing deterioration of a sprayed slope according to the present invention.

8A is a front view showing an example of the result of a visual inspection of the sprayed slope 11, and FIG. 8B is a front view in which the back properties by thermal image interpretation are added to FIG.

FIG. 9 is an explanatory diagram in which aging cases of the spraying slope 11 are classified.

FIG. 10 is a detection characteristic diagram of a conventional thermal infrared imaging method.

[Explanation of symbols]

7: thermal infrared imaging device, 10: ground, 11: spray surface, 12: detector, 13: control unit, 14: display unit, 1
5: Image recording device, 16: Image output device, 17: Image processing / analysis device, 18: Thermal infrared ray, 19: Spray mortar, 20: Hollow portion, 21: Earth and sand portion, 22: Healthy portion, 23
... Wetting section, 24 scanning section, 25 optical section, 26 photoelectric conversion section, 27 preamplifier, 28 detection section control section, 29
... Amplifier, 30 A / D converter, 31 Image memory, 3
2: D / A converter, 34: color encoder, 35: C
PU, 36: I / F, 37: Operation panel, 38: Target,
39: radiation thermometer, 40: visible video, 41: weather data input unit.

[Procedure amendment]

[Submission date] November 22, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 7

FIG. 9

FIG. 3

FIG. 4

FIG. 6

FIG. 10

FIG. 5

FIG. 8

 ──────────────────────────────────────────────────続 き Continuation of the front page (71) Applicant 000213909 Asahi Koyo Co., Ltd. 3-1-1 Higashiikebukuro, Toshima-ku, Tokyo (71) Applicant 596118600 Nc Sanei Co., Ltd. 1-57-57 Tenjincho, Kodaira-shi, Tokyo ( 71) Applicant 391007747 Kowa Co., Ltd. 5295 No.2, Komachicho, Niigata City, Niigata Prefecture (71) Applicant 596139993 PKI Consultants Co., Ltd. 11-11, Wakita Honcho, Kawagoe City, Saitama Prefecture (71) Applicant 592059736 Daito Construction Industrial Miyazaki-shi, Miyazaki-shi Oaza 1050 Hieda, Aka-e (72) Inventor Hiroshi Miki 1, Asahi, Tsukuba-shi, Ibaraki Prefectural Ministry of Construction, Public Works Research Institute, Ministry of Construction, Materials Engineering Department, Soil Engineering Laboratory (72) Inventor Shinhiro Tsutsumi, Ibaraki No. 1 Asahi, Ministry of Construction, Public Works Research Laboratory, Construction Department, Materials Construction Department (72) Inventor Mitsuhiro Furuta, Ibaraki Prefecture No. 1, Asahi, Bashi-shi (72) Inventor: Akiyoshi Ishibashi, 2304 Takasaki, Kakizaki-cho, Inashiki-gun, Ibaraki Prefecture, Japan Nippon Koei Central Research Laboratory (72) Inventor: Noriyuki Arai, Kanagawa 2570-4 Shimotsuruma, Yamato-shi, Japan Nishimatsu Construction Co., Ltd.Technical Research Institute (72) Inventor Nagamasa Yasuda 5-11-3 Shimbashi, Minato-ku, Tokyo Toko Construction Co., Ltd. (72) Inventor Kazunori Takada Nerima-ku, Tokyo Hikarigaoka 1-3-3-203 (72) Inventor Tetsushi Matsunaga 1-57, Tenjin-cho, Kodaira-shi, Tokyo Inside NSC Sanei Co., Ltd. (72) Inventor Yuzo Kobayashi 5295, 2nd-cho, Niigata City, Niigata City, Niigata Prefecture Kowauchi Co., Ltd. (72) Inventor Hideto Hasegawa 11-27 Wakita Honcho, Kawagoe-shi, Saitama In-house Consultants Co., Ltd. (72) Inventor Tatsuro Kawasaki 1050 Hieda, Akae Aida, Daiji Construction, Miyazaki-shi, Miyazaki Prefecture Industrial

Claims (5)

[Claims] The present invention is characterized in that a distribution and a temporal change of a surface temperature on a protective spraying slope 11 of a ground 10 are detected, and a structure behind the spraying slope 11 is estimated from a temperature difference between two times. Aging diagnosis method for sprayed slopes. 2. An analysis thermal image showing a distribution and a temporal change of a surface temperature on a protective spraying slope 11 of the ground 10 and a factual investigation on a back surface of the spraying slope 11 by drilling or the like, and a spraying slope 11 is obtained. A method for diagnosing the aging of sprayed slopes, wherein the structure behind the slope is estimated. 3. Inversion phenomena of the relative temperature difference between the respective parts of the spraying slope 11 due to daytime solar radiation, the relative temperature difference at night, and the relative temperature relationship between morning and evening. 3. The method for diagnosing deterioration of a sprayed slope according to claim 1 or 2, wherein whether the property behind the sprayed slope 11 is a hollow portion 20, a soil portion 21, a healthy portion 22, or a wet portion 23 is determined. 4. The interpretation of the thermal image and the arrangement of the results are performed by comparing the thermal image with the visible image to confirm the positional relationship between the thermal image and the spraying surface 11, and by arranging the thermal images at two times, Extracting a part that shows high or low temperature as a unique temperature change while comparing, and giving meaning to the part showing a unique temperature change from the temperature change pattern by the preset deformation type, and from the thermal image 4. The method for diagnosing deterioration of a sprayed slope according to claim 1, further comprising the step of creating a thermal image interpretation drawing based on the interpreted deformed portion and the result of the visual inspection. 5. A detector 1 for detecting a surface temperature distribution and a change with time in a protective spraying slope 11 of a ground 10.
2, a visible video 40 for recording the surface condition of the spraying slope 11, a weather data input unit 41 for observing and recording weather data, and a correction circuit for converting a temperature signal from the detector 12 into infrared rays. The control unit 13 reads and outputs the temperature data converted into a digital signal together with the character data in a television format, and the display unit 14, the image recording device 15, and the image output device connected to the control unit 13. An aging diagnostic device for a sprayed slope, comprising: an image output device 16;