Support system

Abstract

To provide a support system that supports a shield method by analyzing with highly accuracy the quality relating to a segment ring constructed in the shield method.SOLUTION: A support system comprises: measurement means for scanning an inner peripheral surface of a segment ring to obtain a three-dimensional point group; and analysis means for analyzing the three-dimensional point group. The analysis means generates a cylindrical model corresponding to the segment ring by sampling a point group where a distance apart from a reference position is settled within a prescribed range, develops the cylindrical model in a plane by converting each of a circumferential direction of the cylindrical model, a vertical direction of the circumferential direction, and a separating direction from the reference position to each of three-axial directions in a three-dimensional space, and outputs an analysis result relating to quality determination of the segment ring by analyzing the point group developed in a plane.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a support system for supporting the construction of a tunnel by the shield method.

Background Art

[0002] There is a generally known construction method in which the ground is excavated using a machine called a shield machine, and a block-shaped wall called a segment is assembled in a ring shape around the hole formed by the excavation to construct a tunnel. This construction method is called the shield method. As surveying techniques applied to the construction of a tunnel by the above shield method, there are techniques disclosed in Patent Document 1 and Patent Document 2.

[0003] Patent Document 1 discloses a technique for managing that segments are properly assembled by detachably attaching a sensor unit that detects physical quantities related to the assembled state to the assembled segments and collecting data via a wireless connection.

[0004] Patent Document 2 discloses a technique in which a three-dimensional measuring instrument is installed in a segment (segment ring) assembled in a ring shape by the shield method, a point group corresponding to the inner peripheral surface of the segment ring is extracted from the measurement points, and the roundness of the inner peripheral surface is calculated based on the coordinate positions of the extracted point group.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] As illustrated in Patent Document 2, when measuring the inner surface of a segment ring using a three-dimensional measuring instrument such as a laser scanner, the accuracy of the coordinate positions of the point cloud corresponding to the inner surface varies from point to point. This can make it difficult to properly capture the shape of the segment ring being measured, sometimes resulting in reduced measurement accuracy.

[0007] The present invention solves the above-mentioned problems and provides a support system for tunnel construction using the shield tunneling method by analyzing the quality of the segment rings constructed in the shield tunneling method. [Means for solving the problem]

[0008] According to the present invention, a support system for a shield tunneling method in which a segment ring is constructed by combining segments in a cavity formed by excavation by a shield machine to extend a tunnel, comprising: a measurement means for scanning the inner circumferential surface of the segment ring and acquiring a three-dimensional point cloud relating to the inner circumferential surface; and an analysis means for analyzing the three-dimensional point cloud acquired by the measurement means, wherein the analysis means extracts from the three-dimensional point cloud points whose distance from a reference position, which is either the center position of the segment ring or the position of the measurement means at the time of scanning, falls within a predetermined range, generates a cylindrical model corresponding to the segment ring, converts the circumferential direction of the cylindrical model, the direction perpendicular to the circumferential direction, and the direction of separation from the reference position into the three axial directions in three-dimensional space, respectively, unfolds the cylindrical model into a plane, and analyzes the point cloud obtained by unfolding the cylindrical model into a plane, Identify the point clouds corresponding to each of the multiple segments constituting the segment ring, and for each of the identified point clouds corresponding to the segment, generate a distribution map showing the distance from the reference position. Analysis results regarding the determination of the quality of the aforementioned segment ring The generated distribution map is A support system is provided that is characterized by outputting an output. According to the present invention, a support system for a shield tunneling method in which a segment ring is constructed by combining segments in a cavity formed by excavation by a shield machine to extend a tunnel, comprising: a measurement means for scanning the inner circumferential surface of the segment ring and acquiring a three-dimensional point cloud relating to the inner circumferential surface; and an analysis means for analyzing the three-dimensional point cloud acquired by the measurement means, wherein the analysis means extracts from the three-dimensional point cloud points whose distance from a reference position, which is either the center position of the segment ring or the position of the measurement means at the time of scanning, falls within a predetermined range, generates a cylindrical model corresponding to the segment ring, and the circumferential direction of the cylindrical model A support system is provided which, by converting the direction perpendicular to the circumferential direction and the direction of separation from the reference position into the three axial directions in three-dimensional space, the cylindrical model is unfolded into a plane; the point cloud obtained by unfolding the cylindrical model into a plane is analyzed to identify the point cloud corresponding to each of the multiple segments constituting the segment ring; a planar model is generated in which each of the identified point clouds corresponding to the segments is estimated as an individual rigid plate; a distribution map representing the distance from the reference position is generated for each of the generated planar models; and the generated distribution map is output as an analysis result for determining the quality of the segment ring. According to the present invention, a support system is provided for a shield tunneling method in which a segment ring is constructed by combining segments in a cavity formed by excavation by a shield machine to extend a tunnel, comprising: a measurement means for scanning the inner surface of the segment ring and acquiring a three-dimensional point cloud relating to the inner surface; and an analysis means for analyzing the three-dimensional point cloud acquired by the measurement means, wherein the analysis means extracts a point cloud from the three-dimensional point cloud whose distance from a reference position, which is either the center position of the segment ring or the position of the measurement means at the time of scanning, falls within a predetermined range, generates a cylindrical model corresponding to the segment ring, converts the circumferential direction of the cylindrical model, the direction perpendicular to the circumferential direction, and the direction of separation from the reference position into the three axial directions in three-dimensional space, unfolds the cylindrical model into a plane, analyzes the point cloud obtained by unfolding the cylindrical model into a plane, calculates a judgment value used to determine the quality of the segment ring, generates a distribution map of the calculated judgment value, and outputs the generated distribution map as an analysis result.

[0009] The above invention extracts a point cloud corresponding to the segment ring to generate a cylindrical model, then unfolds the cylindrical model into a plane, and finally outputs the analysis results regarding the quality judgment of the segment ring, thereby ensuring the accuracy of the analysis. Furthermore, the analysis results can be output in a format that allows the analyst to easily understand the results. [Effects of the Invention]

[0010] By analyzing the quality of segment rings constructed using the shield tunneling method, a support system is provided to assist in the construction of tunnels using the shield tunneling method. [Brief explanation of the drawing]

[0011] [Figure 1] This is a flowchart of the surveying algorithm according to the present invention. [Figure 2] This is a schematic diagram showing the positional relationship between the surveying robot and the segment ring. [Figure 3] This is a diagram showing the configuration of a surveying robot. [Figure 4] This figure shows a specific example of a segment ring cut out for measurement. [Figure 5] This figure shows a concrete example of a map that can be generated. [Figure 6] This figure shows a concrete example of a map that can be generated. [Figure 7] This is a schematic diagram showing the gap and misalignment between segments. [Figure 8] This figure shows the measurement results for mesh opening and mesh misalignment. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted where appropriate.

[0013] The implementation of the present invention will be described in accordance with the execution procedure (algorithm) illustrated in FIG. 1. FIG. 1 is a flowchart showing the surveying algorithm according to the present invention.

[0014] The surveying according to the present invention supports a shield method in which segments are combined in a cavity formed by excavation of a shield machine to construct a segment ring and extend a tunnel, and is executed by a surveying robot 100 and an analysis device 200. The surveying robot 100 is equipped with a laser scanner 10, can scan the inner peripheral surface of a target segment ring, and acquire a three-dimensional point cloud related to the inner peripheral surface, corresponding to the measuring means according to the present invention. The analysis device 200 is a computer that analyzes the three-dimensional point cloud acquired by the measurement by the surveying robot 100, corresponding to the analysis means according to the present invention. Note that the analysis device 200 is a general term for a computer that executes the processes of steps S2 to S8 described later, and it is not necessarily required that all processes be executed by one device, and the execution of each process may be shared by a plurality of devices.

[0015] In step S1, the surveying robot 100 disposed in the tunnel measures the inner peripheral surface of the segment ring constructed in the tunnel. The measurement result in step S1 is acquired as a three-dimensional point cloud as described above.

[0016] FIG. 2 is a schematic diagram showing the positional relationship between the surveying robot 100 and the segment ring. More specifically, FIG. 2(a) depicts a state in which the lifting device 20 is contracted and the laser scanner 10 is irradiating the segment ring with a laser, and FIG. 2(b) depicts a state in which the lifting device 20 is extended and the laser scanner 10 is irradiating the segment ring with a laser. FIG. 3 is a configuration diagram of the surveying robot 100. The surveying robot 100 is a device that combines a laser scanner 10, a lifting device 20, an outrigger 30, and a bogie 40. The lifting device 20 raises and lowers the position of the laser scanner 10 by extending and retracting. The outriggers 30 are a mechanism that stabilizes the surveying robot 100 when the center of gravity rises due to the increased position of the laser scanner 10 (extension of the lifting device 20). Furthermore, the outriggers 30 are configured to allow for adjustable leg length, enabling the surveying robot 100 to be leveled even if the ground surface is sloped. The trolley 40 is a wheeled mechanism for moving the laser scanner 10, the lifting device 20, and the outriggers 30. Figure 3 shows a trolley that is pushed by hand, but it may be replaced with a trolley that is remotely controlled or autonomously driven.

[0017] In step S1, when the surveying robot 100 acquires a three-dimensional point cloud, if the laser scanner 10 is at a low position (close to the ground) as shown in Figure 2(a), when the laser is shone from that position, the angle of incidence θ1 for the measurement point near the zenith of the segment ring will be approximately vertical, but the angles of incidence θ2 to θ4 for the other measurement points will be acute, resulting in variations in each angle of incidence. Also, although not shown in Figure 2(a), various objects are placed on the ground at actual construction sites, and if there are objects that block the laser between the laser scanner 10 and the segment ring to be measured, the laser will not reach the parts of the object that are in shadow, making measurement impossible. Due to the factors described above, measurements by the laser scanner 10 at low positions tend to be inaccurate.

[0018] On the other hand, when the surveying robot 100 acquires a three-dimensional point cloud in step S1, if the laser scanner 10 is at a high position (near the center of the segment ring) as shown in Figure 2(b), when the laser is irradiated from that position, the incident angles θ'1 to θ'4 with respect to the measurement points of the segment ring will all be approximately perpendicular, ensuring uniformity of the incident angle. In addition, irradiating with a laser from a high position reduces the number of objects that obstruct the laser between the laser scanner 10 and the segment ring to be measured, thus reducing the number of areas that cannot be measured. Therefore, measurements by the laser scanner 10 at a high position (near the center of the segment ring) are relatively accurate.

[0019] In step S2, the analysis device 200 extracts a point cloud from the three-dimensional point cloud acquired in step S1 that covers the range in which the segment ring to be measured exists. In this embodiment, since the indicator to be measured includes the dimensions of the gap and misalignment between segments, in step S2, the analysis device 200 needs to extract a point cloud that includes a range exceeding the width dimension of at least one segment ring (the dimension in the tunnel's extension direction), that is, a range that includes the segment ring to be measured and the edges of adjacent segment rings. The processing in step S2 reduces the number of point clouds to be processed in steps S3 and beyond, thereby reducing the processing load on the analysis device 200.

[0020] Figure 4 shows a specific example of a segment ring cut out for measurement. As illustrated in Figure 4, in this embodiment, a point cloud corresponding to five adjacent segment rings in the direction of tunnel extension is extracted. In addition to the assembled segment rings, the extracted point cloud also includes point clouds related to other objects installed at the construction site.

[0021] In step S3, the analysis device 200 extracts the point cloud that constitutes the shape of the segment ring (cylindrical shape) from the point cloud extracted in step S2, and excludes point clouds related to objects other than the segment ring. The point cloud extracted in step S3 will be referred to as the cylindrical model in the following description. In step S3, the design value of the tunnel's inner diameter is used in the process of extracting the cylindrical model. Specifically, the analysis device 200 uses the center position of the tunnel (i.e., the center position of the segment ring) as the reference position, and extracts points from the point cloud extracted in step S2 whose distance from the reference position falls within a predetermined range (a range of ± a few centimeters from the design value of the tunnel's inner diameter) to generate a cylindrical model consisting of points corresponding to the segment ring. In addition, the above process may use the center position of the segment ring as the reference position. However, if the position where the laser scanner 10 was located during the measurement in step S1 is close enough to be considered identical to the center position of the segment ring, the position where the laser scanner 10 was located may be treated as the reference position.

[0022] In step S4, the analysis device 200 unfolds the cylindrical model extracted in step S3 into a planar shape. The process of unfolding the data into a plane in step S4 is a process of converting the coordinate information of the point cloud before unfolding (i.e., the point cloud corresponding to the cylindrical model) into coordinate information on a plane. More specifically, the analysis device 200 converts the circumferential direction of the cylindrical model, the direction perpendicular to the circumferential direction, and the direction of separation from the reference position into the three axial directions in three-dimensional space. At this point, it is important in implementing the present invention that the coordinates in the direction of separation from the reference position for the point cloud corresponding to the cylindrical model are converted to the coordinates in the thickness direction of the planar model, which will be described later. It should be noted that the process in step S4 is not a process of dimensionality reduction of a point cloud having three-dimensional coordinate information to two dimensions. This is because the misalignment dimension, which will be described later, corresponds to the dimension in the thickness direction of the planar model.

[0023] In step S5, the analysis device 200 analyzes the point cloud unfolded in step S4 to identify the point cloud corresponding to each of the multiple segments that make up the segment ring, and assigns identification information (ID) to each identified segment.

[0024] In step S6, the analysis device 200 performs an estimation process that treats the point cloud corresponding to each segment identified in step S5 as an individual rigid plate. Each of the segments estimated as a rigid plate in step S6 will be referred to as a planar model in the following description. Since a planar model is a hypothetical three-dimensional model treated as a rigid plate, unlike analysis of point clouds, it can be subjected to surface analysis or line analysis.

[0025] In step S7, the analysis device 200 analyzes the point cloud corresponding to the target segment among the segments identified in step S5, or the planar model (generated in step S6) corresponding to that segment, generates a distribution map of a predetermined format, and outputs the generated distribution map. Each of the distribution maps generated in step S7 will be referred to as a map in the following description. The analysis device 200 according to this embodiment generates four types of maps, which are shown in Figures 5 and 6. Note that the maps shown here are merely specific examples of the output formats of the analysis results output by the analysis device 200. Therefore, in implementing the present invention, the analysis device 200 does not necessarily need to be able to output all the formats shown in the drawings. Furthermore, in implementing the present invention, the analysis device 200 may output analysis results in other formats not shown.

[0026] The map in Figure 5(a) shows the distribution of the calculated separation distances from the reference position for each of the point clouds corresponding to the segment to be measured (the segment shown in the center of the figure) and the segments adjacent to that segment. The map shows the separation distance by the intensity of the color, with darker colors indicating a larger separation distance and lighter colors indicating a smaller separation distance. In this map, the white areas correspond to areas where neither the segment to be measured nor adjacent segments exist, areas at the joints between segments, or areas where point clouds that were not extracted in step S3 exist (point clouds that are outside the extraction range because of the presence of bolts, etc., used in the assembly of the segment).

[0027] The map in Figure 5(b) shows the distribution of the distance from the reference position for each of the planar models corresponding to the segments shown in Figure 5(a). The map uses shades of color to indicate the distance, with darker colors indicating a larger distance and lighter colors indicating a smaller distance. Furthermore, the variation in color intensity within the same segment in the planar model is due to the segment being tilted from the lighter areas towards the darker areas.

[0028] The map in Figure 6(a) shows the distribution of mesh opening dimensions between the segment being measured (the segment shown in the center of the figure) and the segments adjacent to that segment. The map in Figure 6(b) shows the distribution of the misalignment dimensions occurring between the segments shown in Figure 6(a). Each map uses shades of color to indicate the size of the mesh opening or misalignment, with darker colors indicating a larger size and lighter colors indicating a smaller size.

[0029] In this embodiment, the judgment values ​​used by the analysis device 200 to determine the quality of the segment ring are the mesh opening dimension and the misalignment dimension. Therefore, the maps in Figures 6(a) and 6(b) can be said to be distribution maps of the judgment values ​​used for this quality determination. However, the judgment values ​​used to determine the quality of the segment ring are not limited to the above example. For example, the distance of each segment from the reference position may be used to determine the quality of the segment ring. In this modified example, the maps in Figures 5(a) and 5(b) can be said to be distribution maps of the judgment values ​​used for determining quality.

[0030] The concepts of eye gap and eye misalignment will be explained here using Figure 7. As described above, in the shield tunneling method, a tunnel is constructed by assembling segment rings within the cavity formed by excavation by a shield machine. However, when assembling the segment rings, gaps and steps occur between the segments.

[0031] Figure 7(a) is a schematic diagram illustrating the view from the side opposite the segment. The gap W1 between segments shown in Figure 7(a) is called the joint opening in this technical field. In actual construction, adjacent segments are never perfectly parallel, so the dimensions of the joint opening (gap W1) vary depending on the measurement point, even between the same segments. Figure 7(b) is a schematic diagram illustrating a cross-section of a segment near the gap W1 shown in Figure 7(a). The step W2 that occurs between segments as shown in Figure 7(b) is called a misalignment in this technical field. Similar to the dimensions of the joint opening (gap W1), in actual construction, the dimensions of the misalignment (step W2) vary depending on the measurement point, even between the same segments. Figure 7(b) also illustrates the relationship between the joint opening (gap W1) and the joint opening (gap W3). As shown in the figure, the sum of the dimensions of the joint opening (gap W3) and the dimensions determined by the shape of the segment and joint is equal to the dimensions of the joint opening (gap W1).

[0032] In this embodiment, the shape of the segment joint is as shown in Figure 7(b), so there is a difference between the dimensions of the joint opening (gap W1) and the opening (gap W3). However, there are also segment shapes in which these dimensions are approximately the same. When implementing the present invention with such segments, the gap on the inner circumferential surface side of the segment ring and the gap on the opposite side can be treated as openings without distinction.

[0033] In step S8, the analysis device 200 extracts the analysis results of mesh opening and misalignment at the measurement points specified by the analyst and outputs the extracted analysis results. The analysis results in step S8 are the dimensions of mesh opening and misalignment calculated for map generation related to Figures 6(a) and 6(b) generated in step S7, which are shown in a format that is easily recognizable by the analyst, and specifically, are shown in the display illustrated in Figure 8.

[0034] Each point shown in Figure 8 represents a point cloud (measurement result acquired by the laser scanner 10) located in the vicinity of that measurement point. The straight lines on the right and left in Figure 8 represent the surfaces of the planar models corresponding to adjacent segments at that measurement point (originally the surfaces corresponding to the inner circumferential surface of the segment ring). In Figure 8, the shaded area represents the dimension of the misalignment (corresponding to the step difference W2 shown in Figure 7(b)) on the vertical axis, and the dimension of the joint opening (corresponding to the gap W1 shown in Figure 7(b)) on the horizontal axis.

[0035] As illustrated in Figure 8, when attempting to calculate the dimensions of joint opening and misalignment based on a point cloud, it is difficult to determine which point to use as the reference to appropriately calculate the dimensions of opening and misalignment, which can lead to a decrease in analysis accuracy. On the other hand, using the surface of a planar model as a reference allows for the precise calculation of joint opening and misalignment dimensions, improving the accuracy of the analysis.

[0036] The analysis device 200 according to the present invention performs the surveying according to the present invention using the algorithm described above and performs analysis regarding the quality determination of the segment ring, thereby enabling the acquisition of analysis results with high accuracy. Furthermore, the analysis device 200 according to the present invention can output the obtained analysis results in a format that is easily recognizable by the analyst.

[0037] <Other variations> The embodiment of the present invention is not limited to the embodiments described above, and various modifications and improvements are possible. Modifications not described above are listed below.

[0038] In the above-described embodiment, the analysis results were illustrated by using the dimensions of the joint opening and the misalignment as judgment values ​​for determining the quality of the segment ring. However, the present invention may also be implemented by using the dimensions of the opening as one of the judgment values ​​in addition to these.

[0039] The format of the analysis results output by the analysis device 200 in the above embodiment is merely one specific example, and it is permissible to output the analysis results in other formats as long as the objectives of the present invention are achieved.

[0040] <Note> This embodiment encompasses the following technical concepts. (1) A support system for a shield tunneling method in which a segment ring is constructed by combining segments in a cavity formed by excavation by a shield machine to extend a tunnel, comprising: a measurement means for scanning the inner surface of the segment ring and acquiring a three-dimensional point cloud relating to the inner surface; and an analysis means for analyzing the three-dimensional point cloud acquired by the measurement means, wherein the analysis means extracts a point cloud from the three-dimensional point cloud whose distance from a reference position, which is either the center position of the segment ring or the position of the measurement means at the time of scanning, falls within a predetermined range, generates a cylindrical model corresponding to the segment ring, converts the circumferential direction of the cylindrical model, the direction perpendicular to the circumferential direction, and the direction of separation from the reference position into the three axial directions in three-dimensional space, unfolds the cylindrical model into a plane, analyzes the point cloud obtained by unfolding the cylindrical model into a plane, and outputs an analysis result regarding the quality judgment of the segment ring. (2) The support system according to (1), wherein the analysis means analyzes the point cloud obtained by unfolding the cylindrical model in a plane to identify the point cloud corresponding to each of the plurality of segments constituting the segment ring, generates a distribution map representing the distance from the reference position for each of the identified point clouds corresponding to the segment, and outputs the generated distribution map as the analysis result. (3) The support system according to (1) or (2), wherein the analysis means analyzes the point cloud obtained by unfolding the cylindrical model into a plane to identify the point cloud corresponding to each of the plurality of segments constituting the segment ring, generates a planar model in which each of the identified point clouds corresponding to the segment is estimated as an individual rigid plate, generates a distribution map showing the distance from the reference position for each of the generated planar models, and outputs the generated distribution map as the analysis result. (4) The support system according to any one of (1) to (3), wherein the analysis means analyzes the point cloud obtained by unfolding the cylindrical model in a plane to calculate judgment values ​​to be used for determining the quality of the segment ring, generates a distribution map of the calculated judgment values, and outputs the generated distribution map as the analysis result. (5) The support system according to (4), wherein the determination value is at least one of the dimensions of the gap between adjacent segments or the dimensions of the misalignment between adjacent segments. [Explanation of symbols]

[0041] 100 Surveying Robots 200 Analysis equipment 10 Laser Scanners 20 Lifting device 30 Outriggers 40 bogies

Claims

1. A support system for the shield tunneling method, which extends a tunnel by combining segments to construct a segment ring within a cavity formed by excavation by a shield machine, A measurement means for scanning the inner circumferential surface of the segment ring and acquiring a three-dimensional point cloud relating to the inner circumferential surface, Analysis means for analyzing the three-dimensional point cloud acquired by the measurement means, Equipped with, The aforementioned analysis means is A point cloud is extracted from the three-dimensional point cloud whose distance from a reference position, which is either the center position of the segment ring or the position of the measurement means during scanning, falls within a predetermined range, and a cylindrical model corresponding to the segment ring is generated. By converting the circumferential direction of the cylindrical model, the direction perpendicular to the circumferential direction, and the direction of separation from the reference position into the three axial directions in three-dimensional space, the cylindrical model is unfolded into a plane. The point cloud obtained by unfolding the cylindrical model in a plane is analyzed to identify the point cloud corresponding to each of the multiple segments that constitute the segment ring. For each of the point clouds corresponding to the identified segment, a distribution map is generated showing the distance from the reference position. As an analysis result regarding the quality determination of the segment ring, the generated distribution map is output. A support system characterized by the following features.

2. A support system for the shield tunneling method, which extends a tunnel by combining segments to construct a segment ring within a cavity formed by excavation by a shield machine, A measurement means for scanning the inner circumferential surface of the segment ring and acquiring a three-dimensional point cloud relating to the inner circumferential surface, Analysis means for analyzing the three-dimensional point cloud acquired by the measurement means, Equipped with, The aforementioned analysis means is A point cloud is extracted from the three-dimensional point cloud whose distance from a reference position, which is either the center position of the segment ring or the position of the measurement means during scanning, falls within a predetermined range, and a cylindrical model corresponding to the segment ring is generated. By converting the circumferential direction of the cylindrical model, the direction perpendicular to the circumferential direction, and the direction of separation from the reference position into the three axial directions in three-dimensional space, the cylindrical model is unfolded into a plane. The point cloud obtained by unfolding the cylindrical model in a plane is analyzed to identify the point cloud corresponding to each of the multiple segments that constitute the segment ring. A planar model is generated by estimating each of the point clouds corresponding to the identified segment as an individual rigid plate. For each of the generated planar models, a distribution map is generated showing the distance from the reference position. As an analysis result regarding the quality determination of the segment ring, the generated distribution map is output. A support system characterized by the following features.

3. A support system for the shield tunneling method, which extends a tunnel by combining segments to construct a segment ring within a cavity formed by excavation by a shield machine, A measurement means for scanning the inner circumferential surface of the segment ring and acquiring a three-dimensional point cloud relating to the inner circumferential surface, Analysis means for analyzing the three-dimensional point cloud acquired by the measurement means, Equipped with, The aforementioned analysis means is A point cloud is extracted from the three-dimensional point cloud whose distance from a reference position, which is either the center position of the segment ring or the position of the measurement means during scanning, falls within a predetermined range, and a cylindrical model corresponding to the segment ring is generated. By converting the circumferential direction of the cylindrical model, the direction perpendicular to the circumferential direction, and the direction of separation from the reference position into the three axial directions in three-dimensional space, the cylindrical model is unfolded into a plane. The point cloud obtained by unfolding the cylindrical model in a plane is analyzed to calculate a judgment value used to determine the quality of the segment ring. A distribution chart of the calculated judgment values ​​is generated, Output the generated distribution map as the analysis result. A support system characterized by the following features.

4. The determination value is at least one of the dimensions of the gap between adjacent segments or the dimensions of the misalignment. The support system according to claim 3.

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