JP7600063B2 - Tunnel soundness assessment device and inspection support system - Google Patents

Description

The present invention relates to a tunnel soundness assessment device that assesses the soundness of a tunnel by inspecting the inner surface of the tunnel, and an inspection support system equipped with the same.

Inspections of railway tunnels are carried out based on maintenance standards such as "Railway Structure Maintenance Standards and Commentary (Structures Edition) Tunnels" (Railway Technical Research Institute, February 2007), and measures are taken to extend their lifespan. Railway tunnels are about twice as old as road tunnels, and the railway sector is ahead of the others in systematizing inspections.

On the other hand, regular general inspections of tunnels such as railway tunnels and road tunnels involve checking the current situation on-site, extracting any abnormalities such as cracks or spalling, judging the soundness based on the survey data, and then rechecking any areas requiring caution.

As disclosed in Patent Document 1, a tunnel integrity assessment system has been developed that creates an electronic deformation map from crack information extracted from image information or input by an inspector, and assesses the integrity of the tunnel against spalling.

Patent Document 2 discloses an inspection support device for concrete structures that improves the estimation accuracy when identifying the cause of deterioration based on image data of the concrete structure being inspected. This document also discloses an evaluation category for the degree of damage related to cracks in concrete decks.

Furthermore, Patent Document 3 discloses a work support device that uses a measuring unit to measure the structure inside the passageway and uses an illumination unit to illuminate a corrected work position corrected using the measurement results of the measuring unit with light indicating the work area.

JP 2005-207044 A JP 2016-65809 A JP 2021-42073 A

However, as disclosed in Patent Documents 1 and 2, although there is known technology for extracting cracks through image analysis, the soundness of a tunnel is not judged solely by the cracks, and the evaluation results of the soundness are affected by factors such as the crack pattern and the degree of progress of the leak.

In addition, while the types of cracks do not vary significantly depending on the type of concrete structure, such as the deck, building, or tunnel lining, the crack patterns, water leakage, exposed rebar, and other abnormalities have shapes and colors that are unique to tunnels. For this reason, traditionally, skilled technicians (inspectors) have judged the soundness of tunnels by taking into consideration each individual abnormality, but there is variation depending on the inspector.

The present invention aims to provide a tunnel integrity assessment device that can automatically perform a uniform assessment of integrity while taking into account deformations specific to tunnels, and an inspection support system equipped with the device.

In order to achieve the above object, the tunnel soundness determination device of the present invention is a tunnel soundness determination device that determines the soundness by inspecting the inner circumferential surface of a tunnel, and is characterized by comprising an image acquisition unit that acquires an image of the inner circumferential surface of the tunnel, a crack detection unit that detects cracks based on the image, a crack pattern determination unit that determines the pattern of cracks detected by the crack detection unit, a water leakage detection unit that detects a water leakage condition based on the image, a rebar exposure detection unit that detects a rebar exposure condition based on the image, a primary determination processing unit that performs a primary determination based on the detection result of the crack detection unit, and a secondary determination processing unit that performs a soundness determination by adjusting the result of the primary determination processing unit based on the results of the crack pattern determination unit, the water leakage detection unit, and the rebar exposure detection unit.

Here, the system may be configured to include a pre-processing unit that performs digital processing on the image acquired by the image acquisition unit. The secondary assessment processing unit may perform adjustment by performing weighting processing on the results of the primary assessment processing unit, based on the results of the crack pattern assessment unit, the water leakage detection unit, and the exposed rebar detection unit. The system may further include a mesh conversion unit that applies the results of the soundness assessment by the secondary assessment processing unit to the divided regions of the inner surface of the tunnel.

The invention of an inspection support system includes a tunnel soundness determination device according to any one of the above, and a projection device that projects the result of the determination of soundness by the secondary determination processing unit onto the inner circumferential surface of the tunnel, the projection device including a projection unit, a travel unit that mounts the projection unit and moves it in the extension direction of the tunnel, an attitude control unit that controls the attitude of the projection unit, and an output adjustment unit that adjusts the output of the projection unit according to the shape of the inner circumferential surface of the tunnel. Here, the projection device may be configured to include a shape measurement unit that measures the shape of the inner circumferential surface of the tunnel.

The tunnel soundness assessment device of the present invention, configured in this manner, not only has a crack detection unit that detects cracks, but also has a crack pattern assessment unit that determines the crack pattern, a water leakage detection unit that detects water leakage conditions, and a rebar exposure detection unit that detects the rebar exposure conditions.

Then, the results of the primary assessment, which was made based on the detection results of the crack detection unit, are adjusted based on the results of the crack pattern assessment unit, the water leakage detection unit, and the exposed rebar detection unit, and the secondary assessment processing unit assesses the soundness.

This makes it possible to automatically perform a uniform assessment of soundness that takes into account tunnel-specific abnormalities such as crack patterns, water leakage conditions, and exposed rebar conditions. Here, the detection of crack patterns, water leakage conditions, and exposed rebar conditions can be performed efficiently by using the results of processing by a pre-processing unit that digitizes images when detecting cracks from images.

In addition, if the adjustments made by the secondary judgment processing unit are processed using weighting obtained from the results of the crack pattern judgment unit, water leakage detection unit, and exposed rebar detection unit, a more rational and comprehensive judgment can be made with high accuracy.

Furthermore, if a mesh conversion section is provided that applies the results of the soundness assessment made by the secondary assessment processing section to the divided areas of the tunnel's inner surface, it will be easier to identify areas that require re-inspection, such as areas requiring caution after the soundness assessment, and it will be possible to carry out the re-inspection work efficiently.

The invention of the inspection support system also includes a projection device that can project the results of the tunnel soundness assessment made by the tunnel soundness assessment device onto an appropriate location on the inner surface of the tunnel. This makes it possible to efficiently carry out re-inspection work, which must be carried out in a short period of time, such as after train operations have ended, with a small number of inspectors.

In addition, if the projection device is equipped with a shape measurement unit that measures the shape of the tunnel's inner surface, the health assessment result can be projected at an appropriate position on the inner surface even if the tunnel's inner surface has a shape that deviates from a standard cross section or if the positional relationship between the projection device and the tunnel's inner surface changes depending on the position in the tunnel's extension direction.

1 is a block diagram illustrating an overall configuration of an inspection support system according to an embodiment of the present invention. 4 is a flowchart illustrating a process flow of the inspection support system according to the present embodiment. FIG. 11 is an explanatory diagram showing an example of a crack detection situation. 1A and 1B are diagrams illustrating crack patterns, where (a) is an illustration of closure and (b) is an illustration of intersection and parallel. FIG. 1 is a diagram illustrating an example of exposed rebar conditions, where (a) is an overall view of a box culvert-type tunnel, and (b) is an explanatory diagram showing an enlarged view of an exposed rebar area. FIG. 11 is an explanatory diagram showing an example of weighting of anomalies used in the secondary determination process. This is an explanatory diagram showing an example of correcting the results of a primary judgment based on the crack detection results by weighting based on other abnormalities. 11 is an explanatory diagram showing an example of an image screen on which a captured image and a result of a health level determination are displayed as an image, and a mesh screen on which the result of the health level determination is displayed; FIG. FIG. 2 is a perspective view illustrating a configuration of a projection device. 10A is a diagram for explaining the operation of the projection device, where FIG. 10A is a diagram for explaining tilt adjustment, FIG. 10B is a diagram for explaining surveying of the inner periphery of a tunnel, and FIG. 10C is a diagram for explaining projection. These are diagrams explaining the re-inspection work using a projection device, where (a) is an explanatory diagram at the starting point of the re-inspection, (b) is an explanatory diagram during movement and projection, (c) is an explanatory diagram during position adjustment in the tunnel extension direction, and (d) is an explanatory diagram of movement and projection after inspection is resumed. 1 is a perspective view illustrating a situation in which a projection device projects a result of a soundness assessment onto the inner circumferential surface of a tunnel. FIG.

The following describes an embodiment of the present invention with reference to the drawings. FIG. 1 is a block diagram illustrating the overall configuration of an inspection support system 1 according to the present embodiment. FIG. 2 is a flowchart illustrating the process flow of the inspection support system 1 according to the present embodiment.

The inspection support system 1 of this embodiment is a system for inspecting the inner circumferential surface T1 (see Figures 3, 4(a), etc.) formed by the lining of a tunnel T such as a railway tunnel or road tunnel. In short, it is a system for supporting work associated with tunnel maintenance, such as general inspections, by inspecting the inner circumferential surface T1 of concrete structures such as linings constructed from reinforced concrete or unreinforced concrete to determine their soundness.

As shown in FIG. 1, the inspection support system 1 of this embodiment includes a determination device 3 that serves as a tunnel soundness determination device, and a projection device 6 that projects the soundness determination result obtained by the determination device 3 onto the inner surface T1 of the tunnel T.

The determination device 3 determines the soundness of the inner circumferential surface T1 of the tunnel T based on an image of the inner circumferential surface T1 of the tunnel T captured by the photographing device 2 or the like. The photographing device 2 can be an imaging device such as a digital camera, such as an area sensor camera or a line sensor camera. The images captured by the photographing device 2 are stored in a storage unit 21, such as a flash memory (such as an SD memory card), a hard disk, a magnetic disk, or an optical disk.

The determination device 3 captures and uses an image of the inner periphery T1 of the tunnel T. In FIG. 1, the determination device 3 and the photographing device 2 are connected to each other, but the storage unit 21 and the determination device 3 may be connected to each other. For example, the determination device 3 may acquire image data each time photographing is performed by the photographing device 2, or the determination device 3 may acquire image data stored in the storage unit 21 regardless of the time of photographing.

The determination device 3 of this embodiment includes an image acquisition unit 31 that acquires an image of the inner surface T1 of the tunnel T, an image data pre-processing unit 32, a crack detection unit 33 that detects cracks, a crack pattern determination unit 34, a water leakage detection unit 35 that detects water leakage conditions, a rebar exposure detection unit 36 that detects rebar exposure conditions, a primary determination processing unit 37, and a secondary determination processing unit 38 that performs soundness determination.

A storage unit 5, which serves as a storage medium for recording data generated by processing in the determination device 3 and data required for arithmetic processing, is connected to the determination device 3. Examples of the storage unit 5 include a hard disk, a solid state drive (SSD), a flash memory (such as an SD memory card), a magnetic disk, and an optical disk. A cloud server can also be used as the storage unit 5.

The determination device 3 is connected to a display device 4 such as a display. The determination device 3 and the display device 4 can be configured as a determination device 3 mounted on a personal computer or the like and a display device 4 such as a liquid crystal display connected to the determination device 3. The determination device 3 and the display device 4 may also be integrated together, as in a notebook computer or tablet terminal.

The pre-processing unit 32 performs a digitalization process on the images acquired by the image acquisition unit 31. For example, by digitalizing RGB image data, detection data is generated for detecting cracks, leak locations (leakage conditions), and exposed rebar locations (rebar exposure conditions).

The crack detection unit 33 detects cracks that have appeared on the inner surface T1 of the tunnel T from the data digitized by the pre-processing unit 32. Such detectors can be generated by machine learning such as deep learning (multi-layered neural network). In short, the results can be generated by machine learning using high-quality training data before being incorporated as a detector for the crack detection unit 33. Images of deformations in railway tunnels across Japan (approximately 10,000 or more images) can be used as high-quality training data.

The crack detection unit 33 obtains individual information such as crack position, length, angle, and width from the image data. The crack pattern determination unit 34 uses the crack information detected by the crack detection unit 33 to create an unfolded diagram of the crack group and determines the crack pattern that appears in the unfolded diagram.

Details of crack patterns will be described later with reference to Figure 4, but there are various patterns such as closed, intersecting, parallel, and cross-joint. The results generated by machine learning such as deep learning can also be used to determine this crack pattern.

The leak detection unit 35 detects the leak condition on the inner surface T1 of the tunnel T from the data digitized by the pre-processing unit 32. This detector can also use results generated by machine learning such as deep learning. The leak conditions that can be determined are described in detail below with reference to FIG. 6, but include initial, efflorescence, rust, and leak traces.

The rebar exposure detection unit 36 detects the rebar exposure status on the inner surface T1 of the tunnel T from the data digitized by the pre-processing unit 32. This detector can also use results generated by machine learning such as deep learning. The rebar exposure status to be detected will be described in detail later with reference to FIG. 5, but it includes the presence or absence of exposed rebar and the extent of exposure.

The primary judgment processing unit 37 performs a primary judgment based on the detection results of the crack detection unit 33. Details will be described later with reference to FIG. 7, but the individual crack information obtained by the crack detection unit 33 is used to calculate the width and length of the cracks, and the amount of cracks is quantified (TCI value).

Then, the quantified value of the number of cracks (TCI value) is compared with a threshold value set based on empirical values, etc., and the locations of cracks that should be noted when making the final assessment of soundness are output as the primary assessment result.

The secondary judgment processing unit 38 performs a final judgment of soundness by adjusting the results of the primary judgment by the primary judgment processing unit 37 based on the results of the crack pattern judgment unit 34, the water leakage detection unit 35, and the exposed rebar detection unit 36. As will be described in detail later, the results of the crack pattern judgment unit 34, the water leakage detection unit 35, and the exposed rebar detection unit 36 are weighted to correct the judgment results of the primary judgment processing unit 37.

The soundness assessment results from the secondary assessment processing unit 38 are applied to the divided regions of the inner circumferential surface T1 of the tunnel T by the mesh conversion unit 39. As will be described in detail later, data to be projected by the projection device 6 is generated by the mesh conversion unit 39. Details of the projection device 6 will be described later.

Figure 2 is a flowchart explaining the processing flow of the inspection support system 1 of this embodiment. Details will be explained below in accordance with this flowchart and with reference to the examples in Figures 3 to 12.

First, in step S1, an image of the inner circumferential surface T1 of the tunnel T is acquired. The inner circumferential surface T1 of the tunnel T can be photographed by an imaging device 2 such as a digital camera and the image can be input to the determination device 3 in real time, or the image data can be temporarily stored in the memory unit 21 of the imaging device 2 and then input to the determination device 3. In addition, if the determination device 3 is incorporated in a tablet terminal equipped with a camera, the image can be simultaneously acquired by photographing the inner circumferential surface T1 with the camera.

The image data acquired by the image acquisition unit 31 of the determination device 3 is digitized in the pre-processing unit 32 (step S2). For example, the RGB image data is converted into a four-dimensional array with R=256, G=256, B=256 pixels. The digitized data in this way becomes input data for the crack detection unit 33, the water leakage detection unit 35, and the rebar exposure detection unit 36.

In step S3, cracks are detected by the crack detection unit 33. When the digitized data is input to the crack detection unit 33, the detector automatically outputs information about each crack. The crack information includes data about the position on the inner surface T1 of the tunnel T, as well as data about the length, angle, and width of the crack.

The cracks automatically detected by the crack detection unit 33 have position information, and can therefore be output in a development diagram of the inner surface T1 of the tunnel T. Figure 3 shows an example of the crack detection status displayed on the display device 4. In this figure, multiple detected crack lines K are displayed superimposed on a photographed image of the inner surface T1 of the tunnel T. The photographed image also includes the leak location W to be detected in step S32.

In step S31, the crack pattern determination unit 34 determines the crack pattern from the development of the crack group. Figure 4 is a diagram explaining the crack pattern. Figure 4 (a) illustrates an example of a state determined to be a closed pattern. Closure can be a form in which an area surrounded by multiple crack lines K is formed, or a form in which an area surrounded by the construction joints of the tunnel T's lining and multiple crack lines K is formed (joint spanning). When an inner surface T1 that is determined to be closed is tapped, a dull sound is generated, and a skilled inspector (skilled technician) can distinguish this from the surrounding areas where clear sounds are generated.

Figure 4(b) is a diagram explaining the intersecting and parallel forms. Intersecting refers to a form in which multiple crack lines K cross each other in a cross shape, while parallel refers to a form in which adjacent crack lines K run side by side without crossing each other. It is also possible to extract crack lines K with a width of 3 mm or more and determine whether they are intersecting or parallel. Here, intersecting and parallel are determined as one pattern.

In step S32, the leak detection unit 35 detects the leak location and its state as the leak condition. The leak location W shown in FIG. 3 is judged as "rust present." Furthermore, the leak location W where efflorescence is present is judged as "efflorescence present." Other possible states of the leak location W include "initial state" and "leak traces" as shown in FIG. 4(b) and FIG. 5(b).

In step S33, the rebar exposure detection unit 36 detects the locations where rebar is exposed as the rebar exposure status. Figure 5 is an explanatory diagram showing an example of the exposure status of the rebar exposed location R. Figure 5(a) shows an example of an overall view of a box culvert type tunnel BT, and Figure 5(b) shows an enlarged view of the rebar exposed location R that appears on the inner surface BT1 of the upper corner portion. The position and length of the rebar exposed location R are stored as information.

The crack patterns, water leakage conditions, and exposed rebar conditions detected in steps S31 to S33 are used to adjust (correct) the results of the primary assessment process output in step S5, which will be described later. Figure 6 is an explanatory diagram showing an example of weighting of abnormalities used in the secondary assessment process.

As shown in the table in Figure 6, crack patterns are classified as "closed," "crossing/parallel," "crossing joint," and "none." Meanwhile, leakage conditions are classified as "leakage trace," "rust," "efflorescence," "initial stage," and "none." Regarding the exposed rebar conditions, the weights can be changed between "exposed rebar" and "not exposed rebar." If the lining of tunnel T is constructed of unreinforced concrete, the same weight as for "exposed rebar" is used.

There are various methods for weighting, but for example, the results of the primary assessment process can be weighted by increasing the rank by 2 (◎), increasing the rank by 1 (◯), decreasing the rank by 1 (△), etc. (step S34). Here, increasing the rank means that the health level is lowered, in other words, it is getting closer to a location requiring attention. This weighting can also be adjusted according to the region and environment.

Meanwhile, in step S4, a process is performed to convert the crack information obtained by the crack detection unit 33 into a numerical value. Specifically, as shown in FIG. 7, the crack width and length information is integrated to calculate a TCI value that indicates the amount of cracks.

In step S5, a primary assessment of soundness is made based on the TCI value calculated in step S4. Here, soundness is classified in stages from A, B, C, to S, with A being the lowest soundness and S being no soundness problem. A threshold value is set in advance to determine which soundness level the range of the quantified value (TCI value) of the number of cracks is judged to be. Figure 7 shows an example where the TCI value is 3.1 and the primary assessment of soundness is B.

In step S6, a secondary assessment process is performed in which the results of the primary assessment process are corrected based on the detection results of the crack pattern, water leakage status, and exposed rebar status to determine the final soundness. Figure 7 shows an example in which the soundness level has been increased by one rank based on the results obtained by the weighting process in step S34 (e.g., two ranks up, one rank up, one rank down, etc.). By changing the soundness level to A, the area is ultimately determined to be an area requiring attention.

In step S7, the health assessment results performed by the secondary assessment processing unit 38 are sent to the mesh conversion unit 39 and converted into mesh data. Figure 8 is an explanatory diagram showing an example of an image screen M1 on which the captured image and the health assessment results are displayed as images, and a mesh screen M2 on which the health assessment results are displayed.

Both the image screen M1 and the mesh screen M2 are displayed on the display device 4 and can be switched between the two. On the image screen M1, the captured image acquired by the image acquisition unit 31 can be displayed as is, the detected crack lines K can be superimposed, and the soundness assessment results can also be displayed.

Meanwhile, the mesh screen M2 displays the inner surface T1 of the tunnel T, such as the lining, divided into mesh areas of, for example, 1m x 1m. The soundness level given by the secondary judgment processing unit 38 is displayed for these divided mesh areas. Since it would be difficult to understand if all soundness levels were displayed here, it is possible to display only the mesh areas that have been judged to have soundness level A (areas requiring caution), for example, by filling them in dark areas.

Steps S8 and after may be performed in a single sequence up to step S7, or the results of the soundness assessment by the secondary assessment processing unit 38 and the associated mesh data may be temporarily stored in the memory unit 5, and then the steps may be performed in accordance with the timing of a re-inspection of tunnel T.

Figure 9 is a perspective view explaining the configuration of the projection device 6. In order for the projection device 6 to project the soundness assessment result onto the inner circumferential surface T1 of the tunnel T, it is necessary to transmit mesh data to the projection device 6 (step S8).

The projection device 6 includes a projection unit 61, a travel unit 62 for carrying and moving the projection unit 61, an attitude control unit 63 for controlling the attitude of the projection unit 61, an output adjustment unit 64 for adjusting the output of the projection unit 61, and a shape measurement unit 65 for measuring the shape of the inner circumferential surface T1 of the tunnel T.

The projection unit 61 is a laser irradiator that projects the health assessment result converted by the mesh conversion unit 39 onto the inner circumferential surface T1 of the tunnel T using laser light. That is, the laser light irradiated from the projection unit 61 becomes the projection light PL as shown in FIG. 12 and is projected onto the inner circumferential surface T1 of the tunnel T.

On the other hand, the running unit 62 is a cart having multiple wheels 621 for moving in the extension direction of the tunnel T, as shown in FIG. 9. The projection unit 61 is attached to a stand 622 provided on the running unit 62. A rotary encoder is installed on the wheels 621 of the running unit 62, so that the distance traveled by the running unit 62 due to the rotation of the wheels 621 can be measured.

The attitude control unit 63 is equipped with an actuator for controlling the attitude of the projection unit 61. For example, rails laid in a railway tunnel may be installed at a higher position than the inner rail due to cant in curved sections. There may also be track irregularities such as track irregularities. In such cases, the top surface of the running unit 62, which carries the wheels 621 on the rail and moves it, cannot be kept horizontal.

By interposing a posture control unit 63 between the stand 622 of the running unit 62 and the projection unit 61, the projection unit 61 can be adjusted to the desired posture even if the running unit 62 is tilted. The projection unit 61 is attached so that it can move up, down, left and right while being sandwiched between the posture control unit 63 on the lower side and the upper support unit 631 on the upper side.

The orientation of the projection unit 61 can be adjusted by the attitude control unit 63 by an inspector using the operation terminal 66 (see FIG. 10(b)), but it can also be controlled to automatically maintain horizontality. For example, by attaching a sensor unit 632 that measures the orientation of the projection unit 61 in nine axes (three axes each for gyro, acceleration, and earth's axis), and using the signals obtained from the sensor unit 63 to drive the actuator (motor) of the attitude control unit 63, it is possible to always maintain the horizontality of the projection unit 61 even if the running unit 62 is tilted.

The output adjustment unit 64 adjusts the output of the projection unit 61 to match the shape of the inner circumferential surface T1 of the tunnel T to be projected. In other words, the mesh data sent from the mesh conversion unit 39 is data for a plane that matches the development of the inner circumferential surface T1. On the other hand, since the inner circumferential surface T1 of the tunnel T is often not a plane, for example, having a curvature, the output adjustment unit 64 adjusts to correct the projection mesh (mesh data) so that the output matches the shape of the inner circumferential surface T1.

Furthermore, the inner circumferential surface T1 of the tunnel T does not necessarily have a standard cross section, which is the designed cross section, at all points in the extension direction. Also, for tunnels T that were constructed a long time ago, accurate design drawings may not remain. Furthermore, due to the influence of the cant mentioned above, the positional relationship (distance) between the projection device 6 and the inner circumferential surface T1 may change depending on the position in the extension direction of the tunnel T.

Therefore, it is preferable to equip the projection device 6 with a shape measuring unit 65 that measures the shape of the inner circumferential surface T1 of the tunnel T, and to measure the distance between the projection device 6 and the inner circumferential surface T1 before projecting the soundness. The results of the laser measurement performed by the shape measuring unit 65 are input directly to the output adjustment unit 64 and used to adjust the projection mesh.

Figure 10 is a diagram explaining the operation of the projection device 6. Figure 10 (a) is an explanatory diagram during tilt adjustment. As described above, in the curved section of tunnel T, tilt occurs in the running section 62 due to cant, so based on the information on the tilt detected by the sensor unit 632, the actuator of the attitude control unit 63 is driven to hold the projection unit 61 horizontally.

On the other hand, FIG. 10(b) is an explanatory diagram of the measurement of the inner circumferential surface T1 of the tunnel T. Measurement by the shape measuring unit 65 of the projection device 6 is performed, for example, by inputting an angle indicating the measurement range from an operation terminal 66 carried by an inspector. This operation terminal 66 may be one in which the determination device 3 is incorporated, or it may be a dedicated operation device for the projection device 6.

The projection device 6, which has been instructed to specify the measurement range from the operation terminal 66, performs laser measurement within the set angle range by driving the attitude control unit 63 while irradiating the inner circumferential surface T1 of the tunnel T with the measurement laser light SL. The measurement values of the laser measurement are used by the output adjustment unit 64, but the measurement values may also be sent to the operation terminal 66 once, and the results of the calculation process may be received by the output adjustment unit 64 of the projection device 6.

Figure 10(c) is an explanatory diagram during projection. The mesh data corrected by the output adjustment unit 64 according to the set inclination of the projection device 6 and the curvature of the inner circumferential surface T1 of the projection destination is irradiated as projection light PL from the projection unit 61 of the projection device 6.

Figure 11 is a diagram explaining the re-inspection work using a projection device 6. Figure 11(a) is an explanatory diagram of the starting point of the re-inspection, and an alignment mark T3 is attached to joint T2, which is the starting point. The joint spacing of this tunnel T is about 10m-20m.

As shown in FIG. 11(b), the projection device 6, which has been aligned at the starting point, is moved in the extension direction of the tunnel T. The distance traveled from the starting point is measured by the amount of rotation of the wheels 621 of the projection device 6, so the position information of the projection device 6 in the extension direction of the tunnel T is always known.

Then, the projection device 6 is stopped at the position where projection is desired, and the projection light PL is irradiated onto the inner circumferential surface T1 of the tunnel T. Figure 12 is a perspective view illustrating the situation in which the projection device 6 projects the health assessment result onto the inner circumferential surface T1 of the tunnel T.

As shown in this figure, projection by the projection device 6 during reinspection only needs to be performed on areas that are deemed to be "areas requiring caution" and have a soundness level determined to be A. In short, the projection device 6 is automatically moved to the location of the "area requiring caution" by the travel unit 62, and after it stops, the projection unit 61 is pointed in the direction of the "area requiring caution" by the attitude control unit 63, and the "area requiring caution" based on the soundness level determined by the determination device 3 is projected onto the inner surface T1 of the tunnel T (step S9).

In the re-inspection, for areas that were judged to have a soundness level of A in the general inspection, a preliminary check is carried out for an individual inspection in which the cause of the abnormality is estimated, future predictions are made, and a judgment is made as to whether or not measures are required. In the individual inspection, a detailed investigation is carried out using measuring instruments, etc., and a more detailed soundness level (AA, A1, A2) is judged.

Figure 11 (c) shows the situation where the projection device 6 is being realigned at the position of joint T2. By not only measuring the distance with the rotary encoder of the wheel 621 but also adjusting the position using a laser irradiator for each position of joint T2, it becomes possible to accurately grasp the position in the tunnel extension direction. After the position adjustment, inspection is resumed and the projection device 6 is moved and projected, as shown in Figure 11 (d).

Next, the operation of the tunnel soundness determination device 3 according to this embodiment and the inspection support system 1 including the same will be described.
The tunnel soundness determination device 3 of this embodiment, configured as described above, not only includes a crack detection unit 33 that detects cracks, but also a crack pattern determination unit 34 that determines the crack pattern, a water leakage detection unit 35 that detects water leakage conditions, and a rebar exposure detection unit 36 that detects rebar exposure conditions.

Then, the results of the primary assessment, which was made based on the detection results of the crack detection unit 33, are adjusted based on the results of the crack pattern assessment unit 34, the water leakage detection unit 35, and the rebar exposure detection unit 36, and a final assessment of the soundness is made in the secondary assessment processing unit 38.

This allows for automatic and uniform assessment of soundness that takes into account tunnel-specific abnormalities such as crack patterns, water leakage conditions, and exposed rebar conditions. Here, the detection of crack patterns, water leakage conditions, and exposed rebar conditions can be performed efficiently by using the processing results of the pre-processing unit 32, which digitizes images when detecting cracks from images.

In addition, if the adjustments made by the secondary judgment processing unit 38 are processed using weighting obtained from the results of the crack pattern judgment unit 34, the water leakage detection unit 35, and the rebar exposure detection unit 36, it is possible to make a more rational and comprehensive judgment with high accuracy that is comparable to the judgment of an experienced inspector (skilled technician).

Furthermore, if a mesh conversion unit 39 is provided that applies the results of the soundness assessment by the secondary assessment processing unit 38 to the divided areas of the inner surface T1 of the tunnel T, it becomes easier to identify areas that require re-inspection, such as areas requiring caution after the soundness assessment, and it becomes possible to efficiently carry out the re-inspection work.

The invention of the inspection support system 1 also includes a projection device 6 that can project the soundness assessment results obtained by the assessment device 3 onto an appropriate location on the inner circumferential surface T1 of the tunnel T. This makes it possible to efficiently carry out re-inspection work that must be carried out in a short time, such as after train operations have ended, with a small number of inspectors. According to estimates, whereas it previously took four inspectors one night to re-inspect 400 m, it will now be possible for three inspectors to re-inspect 1 km in the same time.

In addition, if the projection device 6 is equipped with a shape measuring unit 65 that measures the shape of the inner surface T1 of the tunnel T, the health assessment result can be projected at an appropriate position on the inner surface T1 even if the inner surface T1 of the tunnel T has a shape that deviates from a standard cross section or if the positional relationship between the projection device 6 and the inner surface T1 of the tunnel T changes depending on the position in the extension direction of the tunnel.

The embodiment of the present invention has been described in detail above with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes that do not deviate from the gist of the present invention are included in the present invention.

For example, in the above embodiment, a case has been described in which the health assessment results converted into mesh data by the mesh conversion unit 39 are projected onto the inner circumferential surface T1 of the tunnel T, but this is not limited to the above, and it is also possible to project the assessment results before conversion to mesh data. Furthermore, the health assessment results to be projected are not limited to "A", which indicates a cautionary area, and other assessment results can also be projected onto the inner circumferential surface T1.

1: Inspection support system 3: Judgment device (tunnel soundness judgment device)
31: Image acquisition unit 32: Pre-processing unit 33: Crack detection unit 34: Crack pattern determination unit 35: Leak detection unit 36: Reinforcement bar exposure detection unit 37: Primary determination processing unit 38: Secondary determination processing unit 39: Mesh conversion unit 6: Projection device 61: Projection unit 62: Travel unit 63: Attitude control unit 64: Output adjustment unit 65: Shape measurement unit T, BT: Tunnels T1, BT1: Inner circumference surface

Claims (6)

A tunnel soundness determination device that determines the soundness of a tunnel by inspecting the inner circumferential surface of the tunnel,
An image acquisition unit that acquires an image of an inner circumferential surface of the tunnel;
A crack detection unit that detects cracks based on the image;
A crack pattern determination unit that determines a crack pattern detected by the crack detection unit;
a water leakage detection unit that detects a water leakage state based on the image;
A reinforcing bar exposure detection unit that detects a reinforcing bar exposure state based on the image;
A primary judgment processing unit that performs a primary judgment based on the detection result of the crack detection unit;
A tunnel soundness determination device characterized by comprising a secondary judgment processing unit which determines the soundness by adjusting the results of the primary judgment processing unit based on the results of the crack pattern judgment unit, water leakage detection unit, and rebar exposure detection unit. The tunnel soundness assessment device according to claim 1, further comprising a pre-processing unit that performs digitization processing on the images acquired by the image acquisition unit. The tunnel soundness determination device according to claim 1 or 2, characterized in that the adjustment by the secondary determination processing unit is performed by performing weighting processing on the results of the primary determination processing unit obtained from the results of the crack pattern determination unit, the water leakage detection unit, and the exposed rebar detection unit. The tunnel soundness assessment device according to any one of claims 1 to 3, characterized in that it is provided with a mesh conversion unit that applies the soundness assessment results obtained by the secondary assessment processing unit to the divided regions of the inner surface of the tunnel. A tunnel soundness determination device according to any one of claims 1 to 4,
a projection device that projects the result of the soundness assessment by the secondary assessment processing unit onto an inner circumferential surface of the tunnel,
The projection device is an inspection support system characterized by comprising a projection unit, a running unit for mounting the projection unit and moving it in the extension direction of the tunnel, an attitude control unit for controlling the attitude of the projection unit, and an output adjustment unit for adjusting the output of the projection unit to match the shape of the inner surface of the tunnel. The inspection support system according to claim 5, characterized in that the projection device is equipped with a shape measurement unit that measures the shape of the inner surface of the tunnel.