Shield tunnel surveying system and surveying method

Abstract

This surveying system efficiently measures segments by using estimated coordinates based on the cumulative distance along the planned line of a shield tunnel to narrow the search range of an automated tracking total station. [Solution] The shield tunnel surveying system according to the present invention comprises a target prism installed in the shield tunnel as a known point, and an automatic tracking total station for surveying either a special staff equipped with a target prism for surveying segments, or a total station equipped with a target prism for calculating its own position. The search center of the automatic tracking total station for the surveying target is determined using the cumulative distance on the planned line of the surveying target, which is obtained by subtracting the distance from the shield machine to the front and rear, determined from the ring number of the segment on which the surveying target is installed, from the cumulative distance on the planned line of the shield machine.

Description

Technical Field

[0001] The present invention relates to a surveying system and a surveying method in a shield tunnel, and particularly to a surveying system and a surveying method in a shield tunnel capable of efficiently surveying segments by narrowing the search range of an automatic tracking total station using estimated coordinates based on the cumulative distance on the planned line of the shield tunnel.

Background Art

[0002] Shield tunnels formed by performing excavation using a shield machine and sequentially assembling segments behind the shield machine after excavation is completed are employed at various construction sites. In the shield construction method, since the shield machine excavates through the ground, a positioning system such as GNSS cannot be used, and it is not easy to confirm the position of the shield machine. Therefore, it is important to daily check whether the excavation is progressing in the correct direction as planned.

[0003] In order to manage the construction accuracy of a shield tunnel, normally, a reference point with a determined position is provided at the starting point of the tunnel, surveying is performed based on this reference point, the position and direction of the shield machine are confirmed, records are kept, and corrections are made as necessary for the subsequent construction. However, since surveying in a shield tunnel is performed after the excavation work is completed, there is a problem that it easily leads to overtime work. Therefore, in order to reduce the surveying work for shield machine surveying, the establishment of automatic surveying and excavation management systems has made it possible to ensure excavation accuracy without frequent surveying.

[0004] Patent Document 1 discloses a shield machine excavation position measurement system, which includes a sighting mirror for measuring the excavation position of the shield machine, a reference point for measurement that serves as the base point for measuring the excavation position of the shield machine set behind the excavation direction of the shield machine, and at least two total stations sequentially placed between the sighting mirror on the shield machine and the reference point set behind the excavation direction of the shield machine, thereby measuring the excavation position of the shield machine relative to the reference point via each total station in sequence.

[0005] Surveying within a shield tunnel is not limited to this; individual segments that make up the formed tunnel also need to be surveyed in order to confirm the route. Multiple segments are assembled and installed for each day of excavation work, but since they are not individually equipped with sighting mirrors or other equipment, manpower is required to survey the segments. Generally, two people, a sighting officer and a field surveyor, go to the surveying site and perform the surveying work together, but a one-man surveying system has been devised to allow one person to perform the survey in order to improve work efficiency.

[0006] Patent Document 2 discloses a shield tunnel surveying system comprising an automatic tracking total station installed using known points within an existing shield tunnel as reference points, a sighting device installed at the surveying position, and a remote control means for operating the total station, wherein the sighting device comprises a straight rod and a prism installed on the straight rod, and the remote control means comprises a voice recognition unit for identifying specific sounds and a communication unit for transmitting a signal to the total station to start surveying.

[0007] According to the invention described in Patent Document 2, an automatic tracking total station is equipped with a communication means that can receive signals from a remote control means to start surveying or transmit surveying data to the remote control means. This allows a surveyor to set up a sighting device on a segment, hold the sighting device, and instruct the total station to start surveying via the remote control means, enabling surveying by a single person.

[0008] Even with an automatic tracking total station, finding the target prism can take time, and the efficiency of the surveying work varies greatly depending on how the search range is set. Patent document 2 describes components that enable surveying by one person, but it does not describe how to set the search range to perform surveying efficiently. Therefore, there is a need for a surveying system that can easily determine the search center according to the installation position of the total station and sighting device, efficiently search for the target prism, and perform automated surveying. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2002-116026 [Patent Document 2] Japanese Patent Publication No. 2024-57409 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The present invention has been made in view of the problems in the conventional surveying systems described above, and the object of the present invention is to provide a surveying system and surveying method that can efficiently survey segments by narrowing the search range of an automatic tracking total station using estimated coordinates based on the cumulative distance on the planned line of a shield tunnel. [Means for solving the problem]

[0011] To achieve the above objective, the shield tunnel surveying system according to the present invention comprises a target prism installed in the shield tunnel as a known point, and an automatic tracking total station equipped with a target prism for calculating its own position for surveying either a rod-shaped special staff equipped with a target prism for surveying segments, or a total station equipped with a target prism for calculating its own position, wherein the search center of the automatic tracking total station for the survey target is determined using the cumulative distance on the planned line of the survey target, which is obtained by subtracting the front-to-back distance from the shield machine, determined from the ring number of the segment on which the survey target is installed, from the cumulative distance from the starting point on the planned line of the shield machine.

[0012] The object to be surveyed is a face-side total station equipped with a target prism to be installed as a mechanical point for special staff to perform surveying and to calculate its own position. The automatic tracking total station for surveying the object to be surveyed is a reference total station installed at a second known point between the known point and the mechanical point. Preferably, the search center of the reference total station for calculating the installation position of the face-side total station is determined based on the estimated coordinates obtained by subtracting the front-to-back distance from the shield machine, which is determined from the ring number of the segment on which the face-side total station is installed, from the cumulative distance from the starting point on the planned line of the shield machine, and the amount of deviation in the left-right and up-down directions from the planned coordinates corresponding to the cumulative distance on the planned line of the face-side total station.

[0013] The object to be surveyed is a rod-shaped special staff attached to a segment as a survey point, with a spirit level and target prisms attached to the center in the longitudinal direction and to the left and right sides of the center along the longitudinal direction. The automatic tracking total station for surveying the object to be surveyed is a face-side total station installed behind the segment assembled on the excavation work side as a known point. Preferably, the search center of the face-side total station for calculating the installation position of the special staff is determined based on the estimated coordinates obtained by subtracting the front-to-back distance from the shield machine, which is determined from the ring number of the segment on which the special staff is installed, from the cumulative distance from the starting point on the planned line of the shield machine, and the amount of deviation in the left-right and up-down directions from the planned coordinates corresponding to the cumulative distance of the special staff on the planned line.

[0014] To achieve the above objective, the shield tunnel surveying system according to the present invention comprises: a target prism fixedly installed on a frame on the inner surface of the shield tunnel as a known point; a face-side total station, which is an automatic tracking total station equipped with a target prism to calculate its own position and installed behind a segment assembled on the excavation work side as a mechanical point; a reference total station, which is an automatic tracking total station equipped with a target prism to be installed at a second known point between the known point and the mechanical point in order to calculate the installation position of the face-side total station; a rod-shaped special staff installed on a segment as a survey point, with a spirit level and target prisms attached at the center in the longitudinal direction and at two locations spaced to the left and right of the center along the longitudinal direction; and the automatic tracking total station. The system comprises a terminal device that mechanically operates a tail-type total station and can connect to a database of a shield tunnel surveying system via communication means, and a database containing a program for surveying using the automatic tracking total station, wherein the reference total station is set up to survey the position of the face-side total station as the survey target, and the face-side total station is set up to survey the special staff as the survey target, and the search center for the survey target of the reference total station or the face-side total station is determined using the cumulative distance on the planned line of the survey target, which is obtained by subtracting the front-to-back distance to the shield machine, determined from the ring number of the segment on which the survey target is installed, from the cumulative distance from the starting point on the planned line of the shield machine.

[0015] Preferably, the face-side total station is equipped with a camera that photographs the direction of the survey, and the camera is configured to transmit images of workers supporting the special staff in real time to the display screen of a control device that can remotely operate the face-side total station from the ground. Preferably, the special staff is further equipped with a distance sensor at its longitudinal center that automatically measures the distance between the center of the special staff and the bottom of the segment tube.

[0016] To achieve the above objective, the present invention provides a surveying method for inside a shield tunnel, comprising the steps of: setting up a target prism inside the shield tunnel as a known point; setting up an automatic tracking total station at a second point from which the known point can be seen, for surveying either a rod-shaped special staff equipped with a target prism for surveying segments, or a total station equipped with a target prism for calculating its own position when set up for surveying the special staff; setting up either of the aforementioned survey targets; and surveying the survey targets using the automatic tracking total station. The surveying step is characterized by including a step of determining a search center for the survey targets using the cumulative distance on the planned line of the survey targets, obtained by subtracting the front-to-back distance from the shield machine, determined from the ring number of the segment on which the survey targets are installed, from the cumulative distance from the starting point on the planned line of the shield machine using a control device equipped with a database for storing surveying programs; and a step of automatically tracking the survey targets using the automatic tracking total station based on the determined search center.

[0017] To achieve the above objective, the surveying method for inside a shield tunnel according to the present invention comprises the steps of: setting a target prism on a frame on the inner surface of the shield tunnel as a known point; setting a reference total station, which is an automatic tracking total station, at a second known point from which the known point can be seen; setting a face-side total station, which is an automatic tracking total station equipped with a target prism for calculating its own position as a mechanical point, behind a segment assembled on the excavation work side of the shield tunnel; the step of the reference total station automatically tracking the target prism of the face-side total station and automatically surveying the face-side total station; and setting a level and target prisms at the center in the longitudinal direction and at two locations separated from the center in the left and right directions along the longitudinal direction as survey points. The method comprises the steps of: setting the attached rod-shaped special staff on the segment to be surveyed; the face-side total station automatically tracking the target prism of the special staff and automatically surveying the survey points; and the terminal device storing the survey data obtained by the automatic survey and transferring it to a control device equipped with a database. The step of automatic surveying by the face-side total station is characterized in that the control device determines a search center for automatic tracking of the special staff based on estimated coordinates obtained by subtracting the front-to-back distance from the shield machine, which is determined from the ring number of the segment on which the special staff is installed, from the cumulative distance on the planned line of the shield machine, and the amount of deviation in the left-right and up-down directions between the cumulative distance on the planned line of the special staff and the planned coordinates.

[0018] Preferably, the automatic surveying step further includes a step of converting the planned coordinates to tunnel center coordinates if the amount of deviation in the left-right and up-down directions from the estimated tunnel center coordinates to the planned coordinates exceeds a predetermined reference amount, by referring to existing survey results in the vicinity. [Effects of the Invention]

[0019] According to the shield tunnel surveying system and surveying method of the present invention, the face-side total station, which is an automatic tracking total station installed on the tunnel face side for segment surveying, is equipped with a target prism for calculating its own position, and can be automatically tracked by a reference total station, which is an automatic tracking total station installed at a second known point. The search center during automatic tracking is determined based on the estimated coordinates obtained by subtracting the front-to-back distance from the shield machine, which is determined from the ring number of the segment on which the automatic tracking total station is installed, from the cumulative distance on the shield machine's planned line, and the left-right and up-down displacement positions of the planned coordinates corresponding to the cumulative distance on the planned line of the automatic tracking total station. Of these, the cumulative distance on the shield machine's planned line can be easily obtained by automatic surveying of the shield machine separately, and the cumulative distance on the planned line of the automatic tracking total station can be easily determined based on the ring number of the segment on which the automatic tracking total station is installed. Therefore, by measuring the lateral and vertical deviations from the planned coordinates corresponding to the cumulative distance on the planned line of the automatic tracking total station, the search center can be easily determined. By performing a search based on the determined search center, the position of the automatic tracking total station for segment surveying can be determined in a short time.

[0020] Further, according to the surveying system and surveying method in a shield tunnel according to the present invention, the search center for automatic tracking of the target prism of the special staff by the working face-side total station is obtained from the cumulative distance on the planned line of the shield machine, determined based on estimated coordinates obtained from the cumulative distance on the planned line calculated by subtracting the front-rear distance relative to the shield machine obtained from the ring number of the segment on which the special staff is installed, and the lateral and vertical displacement positions relative to the planned coordinates corresponding to the cumulative distance of the target prism of the special staff on the planned line. Also in this case, the cumulative distance of the target prism on the planned line can be easily determined based on the ring number of the segment on which the special staff is installed, so the search center for the target prism can be easily obtained by measuring the lateral and vertical displacement positions relative to the planned coordinates corresponding to the cumulative distance on the planned line. By searching based on the obtained search center, the target prism can be found in a short time, and automatic surveying of segments can be performed efficiently.

[0021] Furthermore, according to the surveying system and surveying method in a shield tunnel according to the present invention, a distance sensor that automatically measures the distance between the center of the special staff and the bottom of the segment pipe is provided at the longitudinal center of the special staff, therefore, the distance from the bottom of the segment pipe can be measured immediately when the special staff is installed on the segment, and the vertical displacement of the segment from the planned line can be directly obtained by adding the displacement to the vertical displacement relative to the planned coordinates without calculation from survey data. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] [Figure 1] It is a diagram schematically showing the configuration of a surveying system in a shield tunnel according to an embodiment of the present invention. [Figure 2] It is a diagram showing a method for obtaining a search center in surveying by a reference total station according to an embodiment of the present invention. [Figure 3] It is a diagram showing a method for narrowing down the search center of a reference total station according to an embodiment of the present invention. [Figure 4]It is a diagram illustrating a method of obtaining a search center in surveying by a face-side total station according to an embodiment of the present invention. [Figure 5] It is a diagram illustrating a method of narrowing down the search center of a face-side total station according to an embodiment of the present invention. [Figure 6] It is a diagram showing the configuration of a special staff according to an embodiment of the present invention. [Figure 7] It is a diagram illustrating a one-man surveying method according to an embodiment of the present invention. [Figure 8] It is a diagram illustrating a remote-type surveying method according to an embodiment of the present invention. [Figure 9] It is a flowchart for explaining a surveying method in a shield tunnel according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Next, a specific example of an embodiment for carrying out the in-shield-tunnel surveying system according to the present invention will be described in detail with reference to the drawings. Figure 1 is a diagram schematically showing the configuration of an in-shield-tunnel surveying system according to an embodiment of the present invention.

[0024] The shield tunnel surveying system 1 according to an embodiment of the present invention is a system for efficiently surveying the installation positions of segments 20 that are sequentially constructed in accordance with the excavation in a shield tunnel 2 formed by excavation by a shield machine 10. Referring to Figure 1, the shield tunnel surveying system 1 includes a target prism 30 installed in the shield tunnel 2 as a known point A, a face-side total station 50 which is an automatic tracking total station equipped with a target prism for calculating its own position and installed behind the segment 20 assembled on the excavation work side as a machine point B, and a reference total station 40 which is an automatic tracking total station equipped with a target prism installed at a second known point A between known point A and machine point B in order to calculate the installation position of the face-side total station 50. Furthermore, the shield tunnel surveying system 1 includes a special staff 60 equipped with a target prism to be installed as a survey point C on the segment 20 to be surveyed, a database 81 equipped with a surveying program, and a terminal device 70 that can communicate with the database 81.

[0025] The reference total station 40 and the face-side total station 50 are no different from commercially available automatic tracking total stations, except that they are equipped with a target prism for calculating their own position. The special staff 60 is rod-shaped and includes a spirit level and two target prisms located at the center in the longitudinal direction and at two points spaced apart from the center in the left and right directions along the longitudinal direction. In one embodiment, it is formed by attaching the spirit level and target prisms to a lightweight and rigid aluminum square pipe. The special staff 60 is used by being installed so as to span horizontally between the opposing side walls of the ring-shaped segment 20.

[0026] The terminal device 70 is operated by the surveyor and used to input the data necessary for the survey. The terminal device 70 is equipped with communication means and can communicate with the database 81, the reference total station 40, and the face-side total station 50 via a wireless or wired network. The input data is transmitted to the database 81 or to the reference total station 40 or the face-side total station 50 and used to operate these total stations (40, 50). The terminal device 70 also receives a procedural guidance program, including segment surveying procedures, from the database 81 and displays it on the display screen, functioning to reduce surveying errors by the operator. From the standpoint of work efficiency, the terminal device 70 is preferably small, lightweight, and easy to carry, and is embodied in a tablet device or similar.

[0027] The database 81 is installed in the control device 80 located on the ground and works in conjunction with existing linear management software. It includes a program for displaying known point locations and predicted positions of each survey point, a control program for mechanically operating each total station (40, 50), a search program for automatically finding survey points measured by the automatic tracking total stations (40, 50), a program for automatically calculating machine points and survey point locations from known point coordinates, a procedure guidance program including segment surveying procedures, and a program for recording and transferring survey results to the database in real time.

[0028] The control device 80 includes storage means for storing the database 81, communication means for communicating with terminal devices 70 and each total station (40, 50), input means for inputting various data, and display means for displaying programs or data. The control device 80 is implemented as a personal computer or server, etc.

[0029] Shield tunnel 2 is excavated by the shield machine 10 based on the planned line 4, but it is necessary to proceed while confirming that the shield machine 10 is excavating along the planned line 4 without deviating. For this reason, a shield machine reference point 11 is set up on the shield machine 10. By automatically tracking a target prism installed at the shield machine reference point 11 with an automatic tracking total station, the position and excavation direction of the shield machine 10 can be accurately determined. However, since the shape of shield tunnel 2 is determined by the segments 20 installed by the shield machine 10, surveying the segments 20 is also essential. However, it is not possible to install a target prism on each segment 20 as they are installed sequentially as excavation progresses, so a special staff 60 equipped with a target prism is installed in different locations to conduct the survey.

[0030] In the shield tunnel surveying system 1 according to an embodiment of the present invention, a face-side total station 50 is installed behind the segment 20 to be surveyed, that is, on the side opposite to the excavation direction of the shield machine 10. Then, a special staff 60 is installed on the segment 20 to be surveyed, and the face-side total station 50 automatically surveys the installed special staff 60. This process is repeated for each segment 20, thereby surveying the required range of the segment 20 to be surveyed.

[0031] The tunnel face total station 50 is equipped with a target prism to calculate its own position, making it possible to automatically determine the installation position of the tunnel face total station 50 using the target prism 30 at known point A and the reference total station 40 at a second known point A. Therefore, the installation of the tunnel face total station 50 does not need to be at a known point.

[0032] Furthermore, if the target prism of the face-side total station 50 is a directional prism with a fixed direction of reflection, then after setting up the face-side total station 50, the reference total station 40 can be sighted using the face-side total station 50, and the target prism of the face-side total station 50 can be pointed towards the reference total station 40, enabling automatic surveying by the reference total station 40. If the target prism of the face-side total station 50 is an omnidirectional prism, sighting can be performed from any direction, so it is not necessary to sight the reference total station 40 with the face-side total station 50 in advance as described above.

[0033] In this shield tunnel surveying system 1, the installation position of the face-side total station 50 is automatically measured using the reference total station 40, and the special staff 60 is automatically measured using the face-side total station 50 whose position has been determined. This eliminates the need for two people, a sighting person and a hands-on worker. In other words, surveying can be performed with just one worker to set up the special staff 60, significantly improving work efficiency.

[0034] When performing automatic surveying with an automatic tracking total station, the system searches for a target prism attached to the object to be surveyed and then illuminates the found target prism with light to perform the survey. However, if the search range is wide, it takes time to find the target prism, making efficient surveying impossible. Therefore, this problem can be improved by specifying a narrow range as close as possible to the installation position of the target prism for the automatic tracking total station. In the shield tunnel surveying system 1 according to this embodiment, the cumulative distance L1 of the object to be surveyed is determined by using the cumulative distance L0 of the shield machine, which corresponds to the distance of the shield machine 10 from the starting point 3 of the shield tunnel 2, and the front-to-back distance Δ, which corresponds to the distance between the installation position of the face-side total station 50 or special staff 60 to be surveyed and the shield machine 10. The search center θ is then determined to narrow the search range and achieve efficient surveying.

[0035] The method for determining the search center θ is explained in detail below with reference to Figures 2-5. Figure 2 shows a method for determining the search center in surveying using a reference total station according to an embodiment of the present invention, and Figure 3 shows a method for narrowing down the search center of a reference total station according to an embodiment of the present invention.

[0036] Referring to Figure 2, the situation is shown in which a target prism 30 is installed at a reference known point A inside the shield tunnel 2, and a reference total station 40 is installed at a second known point A that is separated from the target prism 30 and has a clear line of sight to the target prism 30, and the position of the face-side total station 50 installed at machine point B is automatically measured.

[0037] By using two known points A, the direction when sighting the target prism 30 at the reference known point A from the reference total station 40 can be used as the reference angle for the survey, and this angle is set to 0 degrees. In this state, the target prism mounted on the face-side total station 50, which is installed at instrument point B, is sighted from the reference total station 40, and the position of the face-side total station 50 can be determined by measuring the direction and distance. Depending on how the target prism mounted on the face-side total station 50 is attached, the position of the face-side total station 50 and the position of the mounted target prism may be misaligned. In such cases, the amount of misalignment is determined in advance, and the survey results of the reference total station 40 are corrected by the determined amount of misalignment.

[0038] The surveying of the tunnel face total station 50 using the reference total station 40 is performed by automatic tracking, and the efficiency of the work depends on how quickly the target prism of the tunnel face total station 50 can be found. In the shield tunnel surveying system 1, the position of the shield machine 10 and the relative position of the total station 50 to the shield machine 10 are used to determine the search center θ for searching the target prism equipped on the face-side total station 50. Of these, the position of the shield machine 10 is determined as follows.

[0039] A shield machine reference point 11 is set up near the rear end of the shield machine 10 that excavates the face of the shield tunnel 2, and a target prism is installed at the shield machine reference point 11. The position of the shield machine 10 can be measured at any time by automatically tracking the shield machine reference point 11 using an automatic tracking total station set up on the rear side where the shield machine reference point 11 can be sighted. The automatic tracking total station may be the reference total station 40, or a separate automatic tracking total station may be set up to track the shield machine reference point 11 separately from the reference total station 40.

[0040] The position of the shield machine reference point 11 near the rear end of the shield machine 10 is easy to sight from the rear, but it may be a position that is difficult to determine to represent the position of the shield machine 10. Therefore, in this embodiment, the position of the furthest point of the shield machine 10 is set as the arbitrary point 12 of the shield machine, and the arbitrary point 12 of the shield machine is used as the representative position of the shield machine 10. The positional relationship between the shield machine reference point 11 and the arbitrary point 12 of the shield machine can be determined from the structure of the shield machine 10, so the survey data of the shield machine reference point 11 can be converted into positional data of the arbitrary point 12 of the shield machine using this positional relationship. The cumulative distance L0 of the shield machine is determined from the position of the shield machine 10 obtained in this way, which is the distance along the planned line 4 from the starting point 3 of the shield tunnel 2 to the point on the planned line 4 corresponding to the position of the shield machine 10.

[0041] Next, the relative position of the face-side total station 50 with respect to the shield machine 10 is determined as follows. The face-side total station 50 may be installed at any position, but in any case it will be installed on one of the segments 20. Each segment 20 is assigned a unique ring number. By checking the ring number of the segment 20 immediately behind the shield machine 10 and the ring number of the segment 20 on which the face-side total station 50 is installed, the relative position to the shield machine 10 can be determined. That is, the distance between each segment 20 can be determined from the number of segments 20 and the width of the segments 20 obtained from the two ring numbers, and by adding the length from the rear end to the front end of the shield machine 10 to this, the front-to-back distance Δ of the face-side total station 50 relative to the shield machine 10 can be determined.

[0042] The cumulative distance L1 of the object being surveyed is obtained by subtracting the distance Δ before and after from the cumulative distance L0 of the shield machine. In this case, the object being surveyed is the tunnel face total station 50, and the coordinates of the point on the planned line 4 that is at the cumulative distance L1 of the object being surveyed from the starting point 3 become the planned coordinates P of the tunnel face total station 50. From these planned coordinates P, the estimated coordinates Q where the tunnel face total station 50 is installed are determined.

[0043] Figure 3 shows the relationship between the planned coordinates P and the estimated coordinates Q. The installation position of the face-side total station 50 is arbitrary and usually does not coincide with the planned coordinates P, but is offset. Therefore, the estimated coordinates Q of the face-side total station 50 can be determined by measuring the horizontal displacement δx and the vertical displacement δy of the face-side total station 50 relative to the planned coordinates P. The planned coordinates P are points on the planned line 4, but are difficult to grasp within the actual shield tunnel 2. If the shield tunnel 2 is excavated according to the planned line 4, the planned coordinates P coincide with the center of the tunnel cross-section. Even if the shield tunnel 2 is formed off-center from the planned line 4, the displacement is usually in the range of a few millimeters, so in this embodiment, the planned coordinates P are taken as the center of the tunnel cross-section, and the estimated coordinates Q are determined by measuring the horizontal displacement δx and the vertical displacement δy relative to the tunnel center.

[0044] Once the estimated coordinate Q is determined, the direction relative to the estimated coordinate Q obtained from the reference total station 40 is determined, and the search center θ can be determined as a three-dimensional angle relative to the reference angle of 0 degrees. By then transmitting the search range setting based on the search center θ to the reference total station 40, the search range during automatic surveying by the reference total station 40 is precisely narrowed down.

[0045] The target prism of the face-side total station 50 is mounted at a position away from the reference center point used for the next survey by the face-side total station 50. When the reference total station 40 performs automatic surveying, it sights the position of the target prism. Therefore, when determining the search center θ, the three-dimensional displacement to the mounting position of the target prism is added to the estimated coordinate Q. Conversely, the center point position of the face-side total station 50 can be determined by correcting the survey result of the target prism of the face-side total station 50 only by the three-dimensional displacement to the mounting position of the target prism.

[0046] Next, we will explain how to determine the search center θ when surveying with a special staff 60 using a total station 50 on the tunnel face. Figure 4 shows how to determine the search center in a survey using a face-side total station according to an embodiment of the present invention, and Figure 5 shows how to narrow down the search center of a face-side total station according to an embodiment of the present invention.

[0047] Referring to Figure 4, the arrangement remains the same as in Figure 2, with a reference total station 40 installed at the second known point A, and a face-side total station 50 also installed. However, the installation position of the face-side total station 50 is a new known point A determined by the survey using the reference total station 40, and a special staff 60 is installed on the segment 20 where the survey is to be performed. Furthermore, it is assumed that the position of the shield machine 10 has been determined by automatic surveying of the shield machine 10, and that the cumulative distance L0 of the shield machine has already been determined.

[0048] In the surveying by the special staff 60, the target prism mounted on the reference total station 40, which is set up at the second known point A, plays the role equivalent to the target prism 30 in Figure 2. Therefore, the target prism mounted on the reference total station 40 is sighted using the face-side total station 50, and the direction at this time is set to 0 degrees as the reference angle for the survey.

[0049] Next, the face-side total station 50 automatically tracks the target prism attached to the special staff 60 and performs automatic surveying. In this case, the method for determining the search center θ is the same as explained with reference to Figures 2 and 3, by determining the cumulative distance L1 of the survey target and using it to determine the search center θ. As mentioned above, after determining the cumulative distance L0 of the shield machine, the ring number of the segment 20 immediately following the shield machine 10 and the ring number of the segment 20 on which the special staff 60 is installed are checked to determine the front-to-back distance Δ of the special staff 60 relative to the shield machine 10. Since the segment 20 has a predetermined width, if the installation position of the special staff 60 differs depending on the segment 20, errors are likely to occur when determining the search center θ. Therefore, it is preferable to determine the installation position of the special staff 60, for example, near the face-side end of each segment 20.

[0050] The calculated distance Δ is subtracted from the cumulative distance L0 of the shield machine to obtain the cumulative distance L1 of the object being surveyed. In this case, the object being surveyed is the special staff 60, and the coordinates of the point on the planned line 4 that is at the cumulative distance L1 of the object from the starting point 3 become the planned coordinates P of the special staff 60. From these planned coordinates P, the estimated coordinates Q where the special staff 60 is installed are determined.

[0051] As shown in Figure 5, the special staff 60 is rod-shaped and has a total of three target prisms 61: one at the center along its longitudinal direction and two at points spaced to the left and right of the center along its longitudinal direction. Therefore, the estimated coordinate Q is determined for each target prism 61. Figure 5 shows the positional relationship between the lateral displacement δx and the vertical displacement δy from the planned coordinate P for the left target prism 61. In this case as well, the planned coordinate P may be the tunnel center, which is the center of the segment 20 on which the special staff 60 is installed.

[0052] Normally, shield tunnel 2 is excavated along the planned line 4, so the tunnel center and points on the planned line 4 basically coincide. However, if the tunnel center and points on the planned line 4 overlap in a specific direction within the margin of error, a large discrepancy may occur between the survey results and the planned line 4. Therefore, in this embodiment, if the amount of deviation (δx, δy) in the left-right and up-down directions between the estimated tunnel center coordinates and the planned coordinates P exceeds a predetermined reference amount, the planned coordinates P are converted to tunnel center coordinates by referring to the survey results of the vicinity of the object being surveyed. For example, the survey results of nearby segments 20 that have been surveyed in work up to the previous day or the trajectory of the shield machine reference point 11 can be referred to. The result of converting the planned coordinates P to tunnel center coordinates is recorded in the database 81 and reflected in the excavation plan for the following day and beyond.

[0053] Once the estimated coordinate Q is determined for each target prism 61, the search center θ can be set for the obtained estimated coordinate Q. By then transmitting the search range setting based on the search center θ to the tunnel face total station 50, the search range during automatic surveying by the tunnel face total station 50 is precisely narrowed down.

[0054] Figure 6 shows the configuration of a special staff according to one embodiment of the present invention. Referring to Figure 6, the special staff 60 is equipped with target prisms 61 at a total of three locations: the center in the longitudinal direction and two locations spaced to the left and right of the center along the longitudinal direction. It is also equipped with an automatically measuring distance sensor 62 at the center in the longitudinal direction. As mentioned above, in order to determine the estimated coordinate Q of the special staff 60, the lateral displacement δx and vertical displacement δy of the target prisms 61 from the planned coordinate P are determined. By measuring the distance h from the center segment 20 of the special staff 60 to the bottom of the tube using the distance sensor 62 located at the center in the longitudinal direction, the vertical displacement δy of the ring-shaped segment 20 relative to the center can be determined. Since the special staff 60 is installed horizontally using a spirit level (not shown), the vertical displacement δy can be applied not only to the central target prism 61 but also to the two target prisms 61 spaced to the left and right of the center. Furthermore, the lateral displacement δx can be repeatedly used by measuring it at the time of installation, as the lateral distance from the center is predetermined when the target prisms 61 are attached to the special staff 60.

[0055] As mentioned above, in one embodiment, the special staff 60 uses a lightweight and rigid aluminum square pipe. However, since it is installed so as to span across the inner surface of the ring-shaped segment 20, cap materials may be attached to both ends of the special staff 60, which have slanted or arc-shaped end faces to allow for stable installation in accordance with the inner surface of the ring.

[0056] Figure 7 shows a one-person surveying method according to an embodiment of the present invention. In the shield tunnel surveying system 1, the face-side total station 50 that surveys segment 20 is an automatic tracking total station, and surveying can be performed remotely by sending surveying data and instructions from the terminal device 70 to the face-side total station 50. Therefore, it is not necessary for two people, a sighting person and a hands-on person, to perform the surveying work, and one worker can perform the survey alone. The surveying worker sets up the special staff 60 horizontally on the segment 20 to be surveyed, and then measures the amount of deviation (δx, δy) from the planned coordinate P of each of the three target prisms 61 of the special staff 60. Normally, the planned coordinate P and the tunnel center at the point corresponding to the planned coordinate P are within the allowable error range, so the amount of deviation (δx, δy) from the planned coordinate P may also be measured as the amount of deviation from the tunnel center.

[0057] After inputting the measurement results into the terminal device 70, they are transmitted along with the ring number of the segment 20 being surveyed to the control device 80, which is equipped with a database 81. The control device 80 then calculates the search center θ of the face-side total station 50 based on the database 81 and sends it back to the terminal device 70. The operator then transmits the search center θ to the face-side total station 50 to instruct automatic surveying. The automatic surveying data from the face-side total station 50 is sent to the terminal device 70, then transmitted from the terminal device 70 to the control device 80, and stored as data in the database 81.

[0058] Figure 8 shows a remote surveying method according to an embodiment of the present invention. Referring to Figure 8, the configuration of the special staff 60 and the terminal device 70 that inputs and transmits measurement data of the amount of displacement are the same as in the embodiment shown in Figure 7, but it differs from the embodiment shown in Figure 7 in that the face-side total station 50 is equipped with a camera 53 that photographs the direction of the survey. The camera 53 is configured to transmit images of the workers supporting the special staff 60 in real time to the display screen of a control device 80 that can remotely operate the face-side total station 50 from the ground. This makes it possible for the operator of the control device 80 on the ground to remotely operate the face-side total station 50 from the ground and survey the target segment 20 while observing the installation status of the special staff 60 and the signals and actions of the workers conducting the survey inside the shield tunnel 2.

[0059] In this embodiment, unlike the one-person surveying method shown in Figure 7, two people are required: one to perform the survey inside the shield tunnel 2 and another to operate on the ground. However, compared to conventional work where two people move into the shield tunnel 2 to perform the survey, the travel time of one person is eliminated, and other tasks such as planning the next day's work can be performed on the ground while the survey is being cleaned up, thus improving work efficiency.

[0060] Furthermore, in the embodiment shown in Figure 8, instead of the directional target prism 51 shown in Figure 7, an omnidirectional prism 52 is provided as the target prism for calculating the position of the face-side total station 50. The omnidirectional prism 52 is suspended and installed below the face-side total station 50. By using a face-side total station 50 equipped with a mechanism for visually adjusting the deviation from the lower reference point, accurate alignment between the face-side total station 50 and the omnidirectional prism 52 becomes possible. Regarding the height direction, the difference between the center point that serves as the reference for the survey of the face-side total station 50 and the height at which the omnidirectional prism 52 is suspended can be measured, and by correcting the survey results of the omnidirectional prism 52, the center point that serves as the reference for the survey of the face-side total station 50 can be determined.

[0061] The combinations of surveying methods and prism types shown in Figures 7 and 8 are just examples and are not limited to these. For example, the face-side total station 50 used for one-man surveying in Figure 7 may be combined with an omnidirectional prism 52 as shown in Figure 8, or the face-side total station 50 used for remote surveying in Figure 8 may be combined with a directional target prism 51 as shown in Figure 7.

[0062] Figure 9 is a flowchart illustrating a surveying method inside a shield tunnel according to an embodiment of the present invention. Referring to Figure 9, the surveying method inside the shield tunnel 2 involves setting up a target prism 30 as a known point A that serves as the basis for the survey in step S910.

[0063] Next, in stage S920, a reference total station 40, which is an automatic tracking total station equipped with a target prism to calculate its own position, is installed at a second known point A from which known point A, where the target prism 30 is installed, can be seen. The reference total station 40 is not installed every time; since the target prism it is equipped with functions as the reference known point A when surveying segment 20, it is fixedly installed in the shield tunnel 2 by a frame.

[0064] Furthermore, when the reference total station 40 surveys the installation position of the total station to be used for surveying segment 20, it sights the target prism 30 at known point A in order to set the reference angle to 0. Therefore, the target prism 30 is installed so that it faces the fixed reference total station 40.

[0065] As the shield machine 10 excavates and a new segment 20 is installed, a survey of the newly installed segment 20 is performed after the work is completed. To perform the survey, a face-side total station 50, which is an automatic tracking total station equipped with a target prism to calculate its own position, is installed behind the segment 20 assembled on the excavation work side of the shield tunnel 2 in stage S930. The face-side total station 50 does not need to be installed at a known point A, so it can be installed horizontally on a tripod or similar at any point designated as machine point B. In order to automatically survey the face-side total station 50 from the reference total station 40, the reference total station 40 is sighted in advance and the target prism is set to face the reference total station 40. If the target prism of the face-side total station 50 is an omnidirectional prism 52, it is not necessary to sight the reference total station 40 in advance.

[0066] Next, in stage S940, the reference total station 40 automatically tracks the target prism of the face-side total station 50, and the installation position of the face-side total station 50 is automatically surveyed. At this time, the reference total station 40 first sights the target prism 30 installed at the reference known point A, sets the reference angle to 0 degrees, and then searches for the target prism of the face-side total station 50. By specifying the search center θ to be the installation position of the face-side total station 50, the search range is reduced, and the search and automatic surveying proceed efficiently. For this reason, as described above with reference to Figures 2 and 3, the ring number of the segment 20 on which the face-side total station 50 is installed is input from the terminal device 70, the front-to-back distance Δ of the shield machine 10 to an arbitrary point 12 of the shield machine is calculated, and the cumulative distance L1 of the object to be surveyed is calculated by subtracting the front-to-back distance Δ from the cumulative distance L0 of the shield machine 10. Furthermore, the amount of deviation (δx, δy) from the planned coordinate P at the cumulative distance L1 of the object to be surveyed is measured on the planned line 4 from the starting point 3 to find the estimated coordinate Q. Based on the estimated coordinate Q obtained, the search center θ is determined considering the mounting position of the target prism on the face-side total station 50, and this value is instructed on the reference total station 40.

[0067] After the installation position of the face-side total station 50 is known, in step S950, a special staff 60 equipped with a target prism 61 is placed on the target segment 20 for surveying of segment 20.

[0068] Next, in stage S960, the face-side total station 50 automatically tracks the target prism 61 of the special staff 60 and automatically surveys point C. At this time, the face-side total station 50 first sights the target prism of the reference total station 40 and sets this direction as the reference angle 0 degrees, and then automatically tracks the target prism 61 of the special staff 60 and surveys. At this time as well, the work efficiency will change significantly depending on accurately setting the search center θ of the target prism 61. Therefore, as described above with reference to Figures 4 and 5, the ring number of the segment 20 on which the special staff 60 is installed is input from the terminal device 70, the front-to-back distance Δ of the shield machine 10 to an arbitrary point 12 of the shield machine is calculated, and the cumulative distance L1 of the target to be surveyed is calculated by subtracting the front-to-back distance Δ from the cumulative distance L0 of the shield machine. Furthermore, the amount of deviation (δx, δy) from the planned coordinate P, which is located at the cumulative distance L1 from the starting point 3 to the survey target, is measured on the planned line 4 to determine the estimated coordinate Q. The search center θ is then determined so that this point becomes the center of the search, and this is indicated to the total station 50 on the tunnel face side.

[0069] Once the surveying of one segment 20 is completed, the special staff 60 is moved to the next segment 20 to be surveyed, and the automatic surveying using the tunnel face total station 50 is repeated in the same manner. Whenever a segment is surveyed, or when all segments 20 of the required area have been surveyed, the survey data is sent from the terminal device 70 to the control device 80 and stored in the database 81 (stage S970).

[0070] In the surveying method inside a shield tunnel according to the embodiment of the present invention, since all total stations used for surveying are automatic tracking total stations, surveying can be performed by one worker, making one-man surveying possible. Remote surveying is also possible through cooperation between one worker inside the shield tunnel 2 who installs a special staff 60 using a face-side total station 50 equipped with a camera 53, and one operator of a control device 80 on the ground.

[0071] Although embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the technical scope of the present invention. [Explanation of Symbols]

[0072] 1. Shield tunnel surveying system 2 Shield tunnel 3 Starting point 4 Planned lines 10 Shield Machines 11 Shield machine reference point 12 Shield machine at any point 20 segments 30, 51, 61 Target Prisms 40. Standard Total Station 50 Total station on the face side 52 Omnidirectional Prism 53 Cameras 60 Special Staff 62 Distance Sensor 70 Terminal devices 80 Control device 81 Databases A Known point B Machine point C station L0 Shield Machine Cumulative Distance L1 Cumulative distance of the survey target P Plan Coordinates Q Estimated coordinates Δ Anteroposterior distance δx: Amount of displacement in the left-right direction δy: Amount of displacement in the vertical direction θ Search center

Claims

1. As known points, the target prism installed inside the shield tunnel, The system comprises either a rod-shaped special staff equipped with a target prism for measuring segments, or a total station equipped with a target prism for calculating its own position, or an automatic tracking total station equipped with a target prism for calculating its own position for measuring the target object. A shield tunnel surveying system characterized in that the search center for the survey target of the automatic tracking total station is determined using the cumulative distance of the survey target on the planned line, which is obtained by subtracting the distance to and from the shield machine, determined from the ring number of the segment in which the survey target is installed, from the cumulative distance from the starting point on the planned line of the shield machine.

2. The aforementioned survey object is a face-side total station equipped with a target prism to be set up as a mechanical point for special staff to perform surveying and to calculate its own position. The automatic tracking total station for surveying the aforementioned object is a reference total station installed at a second known point between the known point and the instrument point. The shield tunnel surveying system according to claim 1, characterized in that the search center of the reference total station for calculating the installation position of the face-side total station is determined based on the estimated coordinates obtained by subtracting the front-to-back distance from the shield machine, which is determined from the ring number of the segment on which the face-side total station is installed, from the cumulative distance from the starting point on the planned line of the shield machine, and the amount of deviation in the left-right and up-down directions from the planned coordinates corresponding to the cumulative distance on the planned line of the face-side total station.

3. The aforementioned surveying object is a rod-shaped special staff attached to a segment as a survey point, with a spirit level and target prisms mounted at the center in the longitudinal direction and at two locations separated from the center in the left and right directions along the longitudinal direction. The automatic tracking total station for surveying the aforementioned survey target is a face-side total station installed behind the segment assembled on the excavation side as a known point. The shield tunnel surveying system according to claim 1, characterized in that the search center of the face-side total station for calculating the installation position of the special staff is determined based on the estimated coordinates obtained by subtracting the front-to-back distance from the shield machine, which is determined from the ring number of the segment on which the special staff is installed, from the cumulative distance from the starting point on the planned line of the shield machine, and the amount of deviation in the left-right and up-down directions from the planned coordinates corresponding to the cumulative distance of the special staff on the planned line.

4. Known points include a target prism fixed in place by a mounting frame on the inner surface of the shield tunnel, The face-side total station is an automatic tracking total station equipped with a target prism to calculate its own position, and is installed behind the segment assembled on the excavation side as a mechanical point. In order to calculate the installation position of the face-side total station, a reference total station is provided, which is an automatic tracking total station equipped with a target prism to be installed at a second known point between the known point and the machine point. A rod-shaped special staff is installed on the segment as a measurement point, and has a spirit level and target prisms attached to the center in the longitudinal direction and to two locations separated from the center in the left and right directions along the longitudinal direction, The aforementioned automatic tracking total station is operated mechanically, and a terminal device capable of connecting to the database of the shield tunnel surveying system via a communication means is provided. It has a database containing a program for surveying using the aforementioned automatic tracking total station, A shield tunnel surveying system characterized in that the reference total station is set up to survey the position of the face-side total station as the surveying target, the face-side total station is set up to survey the special staff as the surveying target, and the search center for the surveying target of the reference total station or the face-side total station is determined using the cumulative distance on the planned line of the surveying target, which is obtained by subtracting the distance before and after the shield machine, determined from the ring number of the segment on which the surveying target is installed, from the cumulative distance from the starting point on the planned line of the shield machine.

5. The aforementioned tunnel face total station is equipped with a camera that photographs the direction of the survey. The shield tunnel surveying system according to claim 3 or 4, characterized in that the camera is configured to transmit images of workers supporting special staff in real time to the display screen of a control device that can remotely operate the face-side total station from the ground.

6. The shield tunnel surveying system according to claim 1, further comprising a distance sensor at the longitudinal center of the special staff for automatically measuring the distance between the center of the special staff and the bottom of the segment pipe.

7. Known points include the stage of installing the target prism inside the shield tunnel, The process involves setting up an automatic tracking total station at a second location where a known point is visible, for surveying either a rod-shaped special staff equipped with a target prism for surveying segments, or a total station equipped with a target prism for calculating its own position when installed for surveying the special staff. The stage of setting up one of the aforementioned survey targets, The process includes the step of performing a survey of the object to be surveyed using the automatic tracking total station, The step of conducting the aforementioned survey is, A control device equipped with a database for storing surveying programs determines the search center for the surveying object by using the cumulative distance on the planned line of the surveying object, which is obtained by subtracting the distance to the front and rear of the shield machine (determined from the ring number of the segment on which the surveying object is installed) from the cumulative distance from the starting point on the planned line of the shield machine, and A surveying method inside a shield tunnel, characterized by including the step of automatically tracking the object to be surveyed using the automatic tracking total station based on the required search center and performing the survey.

8. Known points include the stage of installing the target prism on the mounting frame inside the shield tunnel, The first step is to set up a reference total station, which is an automatic tracking total station, at a second known point from which the known point can be seen. The process involves installing a face-side total station, which is an automatic tracking total station equipped with a target prism to calculate its own position as a mechanical point, behind the segment assembled on the excavation side of the shield tunnel. The steps include: the reference total station automatically tracking the target prism of the face-side total station and automatically surveying the face-side total station; The first step involves setting up a rod-shaped special staff, which has a spirit level and target prisms attached to the center of the longitudinal direction and to two points separated from the center along the longitudinal direction, on both the left and right sides, as a survey point on the segment to be surveyed. The step involves the total station on the tunnel face automatically tracking the target prism of the special staff and automatically surveying the measurement point, The terminal device has the step of saving the survey data obtained by automatic surveying and transferring it to a control device equipped with a database. A method for surveying inside a shield tunnel, characterized in that the step of automatically surveying using the face-side total station includes a step of determining a search center for automatic tracking of the special staff based on estimated coordinates obtained by subtracting the front-to-back distance from the shield machine, which is determined from the ring number of the segment on which the special staff is installed, from the cumulative distance on the planned line of the shield machine, and the amount of deviation in the left-right and up-down directions between the planned coordinates of the special staff and the cumulative distance on the planned line of the special staff.

9. The method for surveying inside a shield tunnel according to claim 8, characterized in that the step of automatic surveying further includes a step of converting the planned coordinates to tunnel center coordinates if the amount of deviation in the left-right and up-down directions from the estimated tunnel center coordinates to the planned coordinates exceeds a predetermined reference amount, by referring to existing survey results in the vicinity.

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