JP2000180164A - Position determination method and target in mini-shield tunneling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position determination method in a mini-shield tunneling method wherein a position of a shield machine can be determined by a single survey worker. SOLUTION: A pair of left and right targets 3 for receiving laser light emitted from a laser positioning device 1 and reflecting it toward the laser positioning device 1 are attached to two positions where the targets are not in contact with a vehicle with a tunnel segment mounted and traveling in a tunnel and with the tunnel segment mounted thereon, which are distant by a predetermined distance in a horizontal direction orthogonal to a tunnel longitudinal direction on an inner wall face of the placed tunnel segment to provide new reference measurement points. Reference measurement points which have been already placed in the same manner as that for the new reference measurement points and have been positioned by the laser positioning device 1 are used to position the new reference measurement points and a shield machine 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position measuring method in a mini shield method and a target used for the method.

[0002]

2. Description of the Related Art The mini shield method is a shield method for small diameters having a finished inner diameter of approximately 0.8 m to 2.0 m. As shown in FIG. 6A, a concrete tunnel segment divided into three in the circumferential direction is assembled into a tunnel hole excavated by a shield machine and formed into a cylindrical shape (referred to as a ring 2), and added in the excavation direction. To form the tunnel wall. In the mini shield method,
In order to carry out construction according to the drawing, the position measurement of the shield machine that excavates the tunnel is an important issue. 2. Description of the Related Art Conventionally, in the position measurement method in the mini-shield method, a method has been adopted in which a reference measurement point for surveying is provided in a tunnel and the position of a shield machine is measured based on the reference measurement point. Specifically, as shown in FIG. 6 (b), reference measuring points A and B are provided by attaching an identifiable mark to the ceiling of the existing ring with a pencil or the like at a distance of 50 m to 60 m, and the position measurement is completed. One worker sets scales up, down, left and right below the reference point B, and
Is held horizontally, and a transit 32 is installed below the reference measurement point A whose position is not measured near the excavation direction, and the staff below the reference measurement point B is installed. The horizontal and vertical angles of the reference measurement point A with the reference measurement point B as the reference are determined, and the position measurement is performed.
As shown in (c), the transit below the reference measuring point A is directed in the excavation direction, and the staff is collimated at a predetermined position C at the rear part of the front shield machine, and the horizontal with respect to the reference measuring point A is set as a reference.・ The position of the shield machine was measured to determine the vertical angle.

[0003]

However, in the above-described conventional position measurement method, two skilled surveying workers based on the reference measurement points provided on the ceiling use the transit and staff as described above. I needed to work. Also,
When the inside diameter of the tunnel is particularly small, such as 0.8 m to 1.2 m, the working space is small, and it is difficult for the worker to move freely, and the surveying operation itself becomes difficult.

[0004] The present invention has been made in view of such circumstances, and an object of the present invention is to solve the above-described problems and to provide one of the following objects.
An object of the present invention is to provide a position measurement method in a mini-shield method that enables a position surveying operator to measure the position of a shield machine, and a target usable therefor.

[0005]

The first feature of the position measuring method in the mini shield method according to the present invention for achieving the object is as described in claim 1 of the claims. A pair of left and right targets that receive laser light emitted from the laser positioning device and reflect toward the laser positioning device are mounted on a vehicle that travels in a tunnel by mounting a tunnel segment and mounted on the vehicle. Attached to two places separated by a predetermined distance in the horizontal direction in a plane perpendicular to the longitudinal direction of the tunnel on the inner wall surface of the laid tunnel segment at a position not in contact with the tunnel segment to form a new reference measurement point, The position measurement of the new reference measurement point and the shield machine is performed based on the reference measurement point that has already been installed in the same manner as the new reference measurement point and has been measured by the laser positioning device. In the Nau point.

The second feature is, in addition to the first feature, as described in claim 2 of the Claims section, wherein the target is located inside the tunnel from the inner wall surface of the tunnel segment. Protruding toward
The point is that the reflection surface is formed at least in front of the tunnel.

According to a third feature configuration, as described in claim 3 of the claims, in addition to the above-described first or second feature configuration, the laser positioning device has a position measured. The point is that the position measurement is performed while rotating the emission direction of the laser light in a plane including a pair of left and right targets and a pair of right and left unmeasured targets or a predetermined position measurement point of the shield machine.

[0008] In the fourth feature configuration, as described in claim 4 of the claims, in addition to the first, second or third feature configuration described above, the laser positioning device is the latest. The pair of targets on the left and right behind the laid tunnel segment by a predetermined distance or more is to be removed except for those remaining at a predetermined interval longer than the mounting interval.

A first characteristic configuration of the target for position measurement in the mini-shielding method according to the present invention for achieving this object is as described in claim 5 of the claims. It has a contact surface that can be contacted with the tunnel segment, and is provided with a joint that can be attached to and detached from the tunnel segment, and a retroreflecting light reflecting surface is formed on a flat plate surface perpendicular to the contact surface. Here, the recursive property refers to a property of reflecting the incident light in the incident direction.

A second feature of the present invention is that the light reflecting surface is circular in addition to the first feature of the invention, as described in claim 6 of the claims.

The operation and effects of the above-mentioned features will be described below. According to the first characteristic configuration of the position measurement method in the mini-shield method according to the present invention, the relative position of each reference measurement point with respect to the laser positioning device is determined from the emission angle of the laser beam and the distance to the reference measurement point, Further, since the cross-sectional shape of the inner wall of the laid tunnel segment (ring) perpendicular to the longitudinal direction of the tunnel is constant, and the pair of left and right targets are provided at a predetermined distance in the horizontal direction, they are sequentially installed. Since the reference measuring point is always attached at the same position in the cross section on the inner wall surface of each ring, the same relative position of each ring is also determined, and based on the same relative position of the measured ring on the tunnel entrance side from the ring to be measured. hand,
The absolute position of the ring provided with the new reference measuring point (for example, the absolute position with the origin at the tunnel entrance) can be sequentially measured. Moreover, the operator only needs to operate the laser positioning device, and the position measurement can be performed by one operator. Furthermore, the position of the shield machine in progress can be sequentially specified by the operation of the laser positioning device by the same worker based on the latest measured reference point of the position. In addition, in the mini shield method, in order to form a new tunnel wall in the direction of excavation,
It is necessary to transport the tunnel segment before assembling to the rear of the shield machine by a vehicle such as a battery car.In this case, it is possible to prevent the pair of targets on the left and right from obstructing the transport of the tunnel segment, and further, Is not installed on the top of the ring inner wall ceiling, so that the installed target does not become an obstacle when the worker moves in a narrow tunnel.

By the way, the reflection characteristic of receiving the laser beam emitted from the laser positioning device on the reflecting surface of the target and reflecting the laser light toward the laser positioning device is determined by the incident angle (incident light and the normal direction of the reflecting surface). If the angle of incidence is not uniform with respect to the angle of incidence, and the incident angle is more than 80 ° and is incident substantially parallel to the reflecting surface, sufficient reflected light intensity may not be obtained and position measurement over a long distance may be difficult. However, according to the second characteristic configuration, even in such a case, the incident angle approaches 0 ° as the target behind the laser positioning device is farther away,
In addition, the closer the angle is to 90 °, the closer the angle is to 90 °. Therefore, since the target having a low reflected light intensity is located near the laser positioning device, it is possible to avoid the problem that the reflected light intensity is insufficient and the position measurement becomes impossible. You can.

According to the third characteristic configuration, both the pair of right and left targets whose position has been measured and the pair of right and left targets whose position has not been measured are both horizontally separated from each other. There is an intersecting plane, and by adjusting the vertical position of the laser positioning device and the inclination angle of the rotating surface in the laser light emission direction, a set of left and right targets whose position is not measured in one rotation of the laser light emission direction Can be measured at once, and it is not necessary to measure the position separately for the left and right sides, thereby improving work efficiency and shortening the measurement time.

According to the fourth characteristic configuration, in order to accurately grasp the position and orientation of the newly-installed ring, when the target is installed for every one or two rings, the target is located far away from the tunnel entrance. It is possible to avoid the problem that the target overlaps back and forth as viewed from the laser positioning device in front of the tunnel and cannot be used as a reference for position measurement.

According to the first characteristic configuration of the target according to the present invention, there is provided a target usable in the position measuring method in the mini-shielding method, which has the effects of the first to fourth characteristic configurations. You can do it. In particular, since the target once attached can be removed at the joint, unnecessary targets can be selectively removed later, and the target located far in the tunnel entrance direction described above is located at the front of the tunnel. It is possible to avoid the problem that the overlap position cannot be used as a reference for the overlap position measurement when viewed from the front.

According to the second characteristic configuration, since the light reflecting surface is circular, the direction of the contact surface is inclined left and right in opposite directions to the left and right, respectively, regardless of the position of the contact surface. Even if it is attached to the laser light, the horizontal scanning distance of the laser light on the light reflecting surface is equal on the left and right, the pulse width of the reflected signal is equal on the left and right, and the position measurement with the same accuracy between the pair of left and right targets can be performed. It is possible.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a position measuring method in a mini shield method according to the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, a measuring system used in the position measuring method includes a laser positioning device 1 installed in a vehicle capable of traveling in a tunnel and a concrete made of concrete divided into three parts in a circumferential direction. Plural sets of targets 3 installed in one set on the left and right sides on the inner wall surface of the ring 2 formed by assembling the tunnel segments into a cylindrical shape, and one set on the left and right sides at a predetermined position A behind the bent part of the shield machine 4 And a target 5 installed.

The laser positioning device 1 can emit a laser beam while rotating the scanning direction by 360 ° in a single scanning plane, and perform the scanning so that the emitted beam enters the targets 3 and 5. The height and inclination of the plane can be finely adjusted. In addition, the light reflected by the targets 3 and 5 is received to receive the target 3,
5 to measure the position of the targets 3 and 5 by measuring the distance to 5 and detecting the emission angle in the scanning plane and the inclination of the scanning plane to specify the emission direction of the laser beam. .

The internal configuration of the laser positioning device 1 is shown in FIG.
As shown in (a), an outgoing / receiving unit 10 for emitting a laser beam and receiving a reflected beam, a modulator 11 for modulating the intensity of the outgoing beam, and a reflected signal obtained by photoelectrically converting the reflected beam. A position detection unit for calculating a distance from a modulation signal used for modulating the output beam and performing position detection.

The light emitting system of the light emitting and receiving unit 10 includes a laser light source 13 such as a semiconductor laser, a collimating lens 14 for collimating the light emitted from the laser light source 13, and a 90 ° bending of the emitted beam passing through the collimating lens 14. The main component is a reflecting mirror 15 that is driven to rotate about a vertical axis by a motor for rotating and scanning 360 ° in the scanning plane. The rotation speed is 5 rotations / second. The light receiving system of the outgoing light receiving unit 10 includes a reflecting mirror 15 that bends the reflected light from the targets 3 and 5 by 90 °, and a beam that separates the reflected light bent by 90 ° by the reflecting mirror 15 from the outgoing light. The main components are a splitter 16 and a light receiving element 17 that converts the light intensity of the reflected light into an electric signal.

The modulation section 11 includes a first oscillation circuit 18 for oscillating a sine wave signal of about several hundred MHz (indicated by "A" in FIG. 3B) and a repetition period of about several .mu.s to about several tens .mu.s. And a pulse oscillator 19 that oscillates a pulse signal (indicated by “B” in the figure). The driving current of the laser light source 13 is modulated by a signal obtained by superimposing the sine wave signal and the pulse signal. The laser light emitted from the laser light source 13 is intensity-modulated into a signal waveform as shown in FIG. The peak value of the pulse signal is sufficiently larger than the amplitude of the sine wave signal, and the modulation intensity of the pulse signal is larger than the modulation intensity of the sine wave signal. Further, as shown in FIG. 3B, the pulse signal and the sine wave signal are synchronized, the pulse width of the pulse signal coincides with the period of the sine wave signal, and the pulse signals are smoothly overlapped with each other. The oscillator 19 oscillates in pulses according to the synchronization signal from the first oscillation circuit 18.

The position detector 12 comprises three comparators 20, 21, 22; two timers 23, 24;
A low-pass filter 25, 26, a second oscillating circuit 27 that oscillates a sine wave signal having an oscillating frequency different from the oscillating frequency of the first oscillating circuit 18 by several hundred MHz to tens of MHz, and a microcomputer. And an arithmetic unit 28. The reflected signal detected by the light receiving element 17 is delayed and out of phase with respect to the output beam in accordance with the distance to the targets 3 and 5 to be measured. Hereinafter, signal processing in each unit for obtaining the distance to the targets 3 and 5 based on the delay and phase information will be described.

The reflected signal detected by the light receiving element 17 is input to the comparator 20. In the comparator 20, the detection level is set high, and only the pulse signal is detected and inputted to the timer 23. The pulse signal from the pulse oscillator 19 is also input to the timer 23, and the input starts the time measurement, measures the delay time t until the pulse signal is input from the comparator 20, and sends the time to the arithmetic device 28. Output. Since the repetition period of the pulse signal (several μs to several tens of μs) is set so as to be longer than the assumed maximum distance to the targets 3 and 5, the light travels back and forth. From the delay time t, a provisional distance D ′ to the targets 3 and 5 is obtained as D ′ = t × c / 2 (c =
speed of light). The calculation result is set as the provisional distance because the measurement accuracy is limited by the time measurement accuracy of the timer 23 and includes a measurement error.

Further, the reflected signal detected by the light receiving element 17 is superimposed on the sine wave signal from the second oscillation circuit 27, and the resulting beat signal is extracted by the low-pass filter 25. The beat signal is shaped into a rectangular wave by the comparator 21 and input to the timer 24. Further, a beat signal generated by superimposing the sine wave signal from the first oscillation circuit 18 and the sine wave signal from the second oscillation circuit 27 is extracted by the low-pass filter 26, and the beat signal is extracted by the comparator 22. The waveform is shaped into a rectangular wave by the above and input to the timer 24. The timer 24 starts counting time together with the input of the rectangular wave from the comparator 22, and outputs a time period T until the rectangular wave is input from the comparator 21 to the arithmetic unit 28.

The arithmetic unit 28 calculates the phase difference between the sine wave signal from the first oscillation circuit 18 and the sine wave signal component included in the reflected signal detected by the light receiving element 17 from the time T. Is converted into a distance φ corresponding to the phase difference, and the distance D to the targets 3 and 5 is calculated as D = (n × λ + φ) based on the distance φ and the provisional distance D ′.
/ 2 is calculated. Here, λ is the first oscillation circuit 18
Where n is (D '/ (λ / 2))
If the difference between D and D ′ is λ / 4 or more, this n is increased or decreased to select n where the difference between D and D ′ is smaller than λ / 4.

The laser positioning device 1 includes the reflecting mirror 15
A rotary encoder 29 for detecting the rotation angle of the reflecting mirror 15 is provided on the rotation axis of the mirror 15. The rotating angle of the reflecting mirror 15 is input to the arithmetic unit 28 as the emission angle of the laser beam in the scanning plane. Therefore, the emission angle and the target 3 calculated in the manner described above,
From the distance D up to 5, the positions of the targets 3 and 5 in the scanning plane are detected. The time required for the position measurement is about 1 μsec, and the position is detected almost instantaneously.

Next, the targets 3 and 5 will be described. As shown in FIG. 4, the target 3 has a diameter of 2 mm.
0 mm disc-shaped main body 3a and the disc-shaped main body 3a interposed between the disc-shaped main body 3a and the inner wall surface of the ring 2.
And a joining portion 3b for attaching the disc-shaped body to the inner wall surface. The disc-shaped main body 3a and the joining portion 3b are detachably adhered to each other. The front and back surfaces of the disk-shaped main body 3a have a diameter of 20 mm.
mm circular retroreflective film is provided. Since the contact surface of the joining portion 3b which comes into contact with the inner wall surface of the ring 2 is formed perpendicular to the reflection film surface which is a light reflection surface, the target 3 is moved to the reflection film surface with respect to the longitudinal direction of the tunnel. It can be installed vertically. That is, the light reflecting surfaces of the pair of left and right targets 3 can be set in the same plane. The reflection film has a large number of so-called corner cubes arranged on the entire surface thereof, and receives the laser beam emitted from the laser positioning device 1 and reflects the laser beam toward the laser positioning device 1. By the way, in the present embodiment, the diameter of the reflection film is determined as a size capable of measuring a target 50 meters away, and is preferably 15 to 20 mm. If the reflection film is too large, a distant target overlaps back and forth when viewed from the laser positioning device 1 and measurement becomes impossible, while if too small, the time during which the laser beam scans the reflection film is shortened. However, sufficient reflected light cannot be obtained and measurement at a distant place becomes impossible. The target 5 is attached with a circular retroreflective film having a diameter of 20 mm facing rearward at the predetermined position A behind the center bend of the shield machine 4, and the light reflecting surfaces of the pair of right and left targets 5 are in the same plane. Formed. Further, the pair of left and right targets 5 are provided at the predetermined position A at a predetermined distance in the horizontal direction in advance.

Next, a position measurement method for measuring the position of the shield machine 4 using the above-described measurement system will be described. First, a method of attaching the target 3 to the inner wall surface of the ring 2 and using it as a reference measurement point for position measurement will be described. The attachment of the target 3 and the position measurement by the laser positioning device 1 are performed by one worker.

As shown in FIG. 5, the target 3
The contact surface is brought into contact with the inner wall surface at the upper left and right sides of the inner wall surface of each ring 2 for every one ring or two rings in a pair of left and right, and the light reflecting surface is installed so as to face the longitudinal direction of the tunnel. At this time, the dedicated staff 6 having a level 7 is pressed against the inner wall surface so that the pair of left and right targets 3 are separated from each other by a predetermined distance W in the horizontal direction, and the left and right installation locations are positioned. It is preferable that the left and right installation points are located at approximately 2 o'clock and 10:00 o'clock on a cross section perpendicular to the tunnel longitudinal direction. The place is a place where the vehicle does not come into contact with the vehicle running in the tunnel with the tunnel segment mounted thereon and the tunnel segment mounted on the vehicle, and hardly comes into contact with the head of the worker during work. Because.
Of the pair of left and right targets 3 installed in this manner, the target whose position has been measured in the manner described later is used as a reference measurement point. In addition, for the sake of convenience,
Called the new reference point.

As described above, the target 3 is newly attached to the newly installed ring 2 every one ring or every two rings, but the existing ring 10 m to 20 m or more behind the newly installed ring 2 is attached. Are left at intervals of 10 to 20 rings, and the other targets are separately removed. Note that the removal operation can be easily performed by removing the disk-shaped main body 3a from the joint portion 3b instead of removing the entire target 3 from the inner wall surface of the ring 2. Also, this removing operation is performed by the shield machine 4
Depending on the propulsion speed, it is usually done several days after installation.

Next, a procedure (procedure 1) for measuring the position of the target 3 at the new reference measurement point based on the reference measurement point will be described. As shown in FIGS. 1 and 2, the pair of targets 3 on the left and right of the reference measurement point C and the pair of targets 3 on the left and right of the new reference measurement point B are horizontally separated from each other in the left and right directions. Exists. Therefore, the laser positioning device 1 is positioned such that the reference measurement point C and the new reference measurement point B are located on the scanning plane P of the beam emitted from the laser positioning device 1.
And the inclination of the scanning plane P are finely adjusted to collimate each target 3. Subsequently, the laser positioning device 1 of the reference positioning point C and the new reference positioning point B by the laser positioning device 1
Is measured relative to. The relative position within the scanning plane P is measured, and from this result, the relative positional relationship between the new reference measuring point B and the reference measuring point C within the same plane P is known. Further, the inclination between the new reference measurement point B and the reference measurement point C can be determined from the inclination of the scanning plane P. Here, since the position of the reference measurement point C has already been measured, the absolute position of the new reference measurement point B (for example, the absolute position with the origin at the tunnel entrance) is derived. In this way, the new reference measuring point becomes the reference measuring point C whose position has already been measured.

It should be noted that even when measuring exactly the same measurement object, a slight error occurs between different measurement results at the time of measurement. For example, when the distance between a pair of left and right targets 50 m away is measured, a measurement error of ± 5.1 mm may occur. Since this error can be reduced by averaging a plurality of measurement results, in the present embodiment, the position measurement is performed by averaging five measurement results. Further, if a pair of left and right targets are measured and the position of the intermediate point is obtained from the intermediate value of the measurement results of both targets, the error can be further reduced.

Next, the position of the target 5 installed at a predetermined position A of the shield machine 4 is determined based on a new reference measurement point B (hereinafter, referred to as reference measurement point B) which has become a new reference measurement point. Perform measurement. The procedure (procedure 2) in this case is executed in exactly the same manner as in procedure 1 except that the reference measurement point C and the new reference measurement point B in procedure 1 are replaced with the reference measurement point B and the target 5 in procedure 2. Detailed descriptions are omitted because they can be made. In the embodiment shown in FIG. 1, the laser positioning device 1 is installed between the shield machine 4 and the reference measuring point B, but the emitted beam rotates 360 ° in the scanning plane and scans in all directions. Therefore, the reference measurement point B and the target 5 can be reliably collimated regardless of the installation position, and the respective position measurements can be performed. That is, it is not necessary to move the laser positioning device 1 in the procedure 1 and the procedure 2.

Next, another embodiment will be described. <1> The laser positioning device 1 used in the above embodiment
Instead, a laser positioning device that performs position measurement based on another measurement principle, or a laser positioning device that employs another emission beam scanning means or another emission angle detection means may be used.

<2> The shapes, structures and dimensions of the targets 3 and 5 may be other than those exemplified in the above embodiment. Further, the reflection film of the target 3 may be provided on only one surface of the disk-shaped main body 3a. However, the target 3 is such that the reflective film surface is forward,
In other words, it needs to be installed facing the excavation direction,
In the above procedure 1, the laser positioning device 1 needs to be installed ahead of the new reference measurement point B.

[Brief description of the drawings]

FIG. 1 is a plan view showing a schematic configuration of a position measuring method and a measuring system used in the method according to the present invention.

FIG. 2 is a side view showing a schematic configuration of a position measuring method according to the present invention and a measuring system used therein.

3A is a block diagram of a laser positioning device, and FIG. 3B is a modulation waveform of an emitted laser beam.

FIG. 4 is a perspective view showing a target according to the present invention.

FIG. 5 is an explanatory view showing an example of setting a target.

FIG. 6 is an explanatory diagram showing a conventional position measurement method.

FIG. 7 is a perspective view showing a staff member used in a conventional position measurement method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser positioning device 2 Ring (tunnel segment) 3 and 5 Target 3a Disk-shaped main body 3b Joint 4 Shield machine 6 Staff 7 Level

Claims (6)

[Claims] A vehicle that travels in a tunnel with a set of left and right targets that receives laser light emitted from a laser positioning device and reflects the laser light toward the laser positioning device on a tunnel segment, and the vehicle. A new reference point is attached at two positions separated horizontally by a predetermined distance in a plane perpendicular to the longitudinal direction of the tunnel on the inner wall surface of the laid tunnel segment at a position not in contact with the tunnel segment placed on And performing the position measurement of the new reference measurement point and the shield machine with reference to the reference measurement point which is already installed in the same manner as the new reference measurement point and whose position has been measured by the laser positioning device. Position measurement method in the mini shield method. 2. The target according to claim 1, wherein the target is mounted so as to protrude from the inner wall surface of the tunnel segment toward the inside of the tunnel, and has a reflection surface formed at least in front of the tunnel. Position measurement method in the mini shield method. 3. The laser positioning device emits laser light in a plane including a pair of left and right targets whose position has been measured and a pair of right and left unmeasured targets or a predetermined position measurement point of the shield machine. 3. The position measuring method according to claim 1, wherein the position is measured while rotating the direction. 4. The laser positioning apparatus according to claim 1, wherein the pair of left and right targets located behind the latest laid tunnel segment by a predetermined distance or more is removed except for those remaining at a predetermined interval longer than the mounting interval. The position measuring method in the mini-shield method according to claim 1, 2 or 3. 5. A contact surface capable of contacting a tunnel segment, a joint portion detachable from the tunnel segment is provided on the contact surface, and a retroreflective light reflecting surface is provided on a flat plate surface perpendicular to the contact surface. Target for position measurement in the formed mini shield method. 6. The target according to claim 5, wherein the light reflecting surface is circular.