JP3659069B2 - Measuring method of internal displacement of excavated section - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for measuring an internal displacement of a ground excavation section such as a tunnel or an underground cavity.
[0002]
[Prior art]
In underground excavation work such as tunnels and underground power plants, there are various types of geology of the planned construction site, such as earth and sand mountains, low-strength soft rocks, and expansive ground mountains. It loosens to the excavation side and the inner space is displaced over time.
[0003]
If the internal displacement is large, leaving it as it is may lead to the collapse of the excavation cross section, and it is necessary to take measures such as changing the support structure. For this reason, conventionally, such an internal displacement is measured by the method shown in FIGS.
[0004]
The measuring method shown in FIG. 4 is a method using the steel tape 1, both ends of the steel tape 1 are held by the jig 2, and the steel tape 1 crosses the excavation cross section to be measured, Fix the jig 2 to the ground with mortar.
[0005]
Then, a displacement meter 3 is provided in the middle of the steel tape 1, and the displacement of the inner space is measured by measuring the length displacement of the steel tape 1 with the displacement meter 3.
[0006]
In this measuring method, if the steel tape 1 is installed as it is, it becomes an obstacle to other work. Therefore, the steel tape 1 and the displacement meter 3 are configured to be detachable each time a predetermined time elapses. These are attached to the jig 2 for measurement.
[0007]
The measurement method shown in FIG. 5 is a method using the light wave range finder 4, and collimates a plurality of targets 5 installed along the excavation cross section to be measured with the light wave range finder 4. By measuring the distance between the two, the displacement of the inner sky is measured.
[0008]
In this measurement method, the target 5 is installed at that position until the measurement is completed, and the optical distance measuring instrument 4 is installed at the same measurement point every time a predetermined time elapses to measure the distance. .
[0009]
However, such a conventional method for measuring the internal air displacement has a technical problem described below.
[0010]
[Problems to be solved by the invention]
That is, in the former measurement method, since the jigs 2 provided at both ends of the steel tape 1 are fixed to the ground with mortar or the like, it takes one or two days for the mortar or the like to harden. There was a problem that could not.
[0011]
In the latter measurement method, the installation position of the light wave range finder 4 must be calculated every time the internal displacement is measured by surveying, and this work is very complicated.
[0012]
Furthermore, these measurement methods have a problem that it takes 30 to 60 minutes at the earliest time from the installation of the equipment to the end of the measurement, and it is difficult to ensure safety at an excavation site where large heavy machinery constantly passes. There was also.
[0013]
The present invention has been made in view of such conventional problems. The object of the present invention is to ensure safety and perform initial measurement immediately after excavation while avoiding complicated work. An object of the present invention is to provide a method for measuring the internal displacement of an excavated cross section.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is fixedly installed at one end of an excavation cross section to be measured, emits a laser beam toward the other end of the excavation end surface, and reflects the emitted laser beam. A pair of first to third sensor heads for receiving light, a first to a third reflecting sheet that is provided on the other end side and the ceiling of the excavation cross section and reflects a laser beam emitted from the sensor head; By constantly irradiating a laser beam from the first and third sensor heads to the first reflecting sheet on the ceiling and the third reflecting sheet on the other end, respectively, and receiving the reflected laser beam, Calculation of distance measurement from the first and third sensor heads to the corresponding first and third reflection sheets, and a prism provided on the other end side from the second sensor head Through the projecting member, the laser beam is always irradiated to the second reflection sheet provided on the ceiling portion, and the reflected laser beam is received, so that the interval between the second sensor head and the second reflection sheet is obtained. The distance measurement value is continuously calculated, and a device having a control unit that stores the obtained distance measurement value every predetermined time is used, and the wavelength of the laser beam is set according to the size of the distance. The excavation is performed by constantly measuring the distance from the first to third sensor heads to the first to third reflection sheets disposed on substantially the same plane corresponding to each of the first to third sensor heads. The inner space displacement of the cross section was obtained.
According to the internal displacement measuring method configured as described above, a sensor head that emits a laser beam toward the other end side and receives reflected light of the emitted laser beam is installed on one end side of the excavation cross section. A reflection sheet is provided on the other end of the excavation cross section or on the ceiling, and reflects the laser beam emitted from the sensor head. The control unit emits the laser beam from the sensor head to the corresponding reflection sheet. Since the reflected laser beam is received and the distance from the sensor head to the corresponding reflecting sheet is calculated, the empty displacement of the excavated cross section is obtained, so that the cross sectional displacement immediately after excavation can be measured.
In addition, since the measurement of such a distance is continuously performed by always emitting a laser beam from the sensor head, even if the laser beam is interrupted due to the movement of a heavy machine, this interrupted state is released. Measurement can be performed immediately, and there is no problem in safety because no human work is involved in recovering such measurement.
In the internal displacement measuring method of the present invention, three sensor heads including the first to third sensors are used, and the first and third sensor heads are used as the first reflective sheet and the third reflective sheet on the ceiling. By irradiating the respective laser beams and receiving the reflected laser beams, the distances from the first and third sensor heads to the corresponding first and third reflecting sheets are calculated, and the other end side from the second sensor head From the second sensor head to the second reflecting sheet by emitting a laser beam to the second reflecting sheet provided on the ceiling through a reflecting member such as a prism provided on the ceiling and receiving the reflected laser beam calculating the distance, from the first to third sensor head, since constantly measures the distance until the first to third reflection sheet disposed substantially in the same plane corresponding to the respective double Allows traverse measurements at points, it is possible to measure the internal air displacement with higher accuracy.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. FIG. 1 to FIG. 3 show an embodiment of a method for measuring an internal displacement of an excavation cross section according to the present invention.
[0016]
In the internal displacement measuring method shown in the figure, three first to third sensor heads 10a, 10b, 10c, three first to third reflection sheets 12a, 12b, 12c, and a control unit 14 are shown. And a personal computer 16 for collecting and storing data.
[0017]
The three first to third sensor heads 10a, 10b, and 10c emit laser beams L having a predetermined wavelength, receive reflected light of the emitted laser beams L, and have a rectangular casing. 100 and a window portion 101 which is provided at one end of the casing 100 and emits a laser beam L and receives reflected light of the emitted laser beam L.
[0018]
The laser beam L emitted from the first to third sensor heads 10a, 10b, and 10c selects a wavelength corresponding to the measurement distance. For example, in the range where the distance is 5 to 10 m, the green color and the distance are selected. Blue is used in the range of 10 to 15 m, gold is used in the range of 15 to 20 m, and white is used in the range of 20 to 25 m.
[0019]
In this case, the first to third reflective sheets 12a, 12b, and 12c may have different reflectivities depending on the wavelength. Therefore, the one having a better reflectivity is selected according to the laser beam L to be used. .
[0020]
In addition, in the case of the present embodiment, the three first to third sensor heads 10a, 10b, 10c can be protected from flying stones due to blasting when used in the field where the blasting method is adopted . As shown in detail in FIGS. 2 and 3, it is housed in a steel box 18.
[0021]
A transparent glass plate 20 capable of transmitting the laser beam L is provided on the front surface of the steel box 18, and each of the first to third sensor heads 10a, 10b, and 10c has a window 101. The fine adjustment jig (not shown) is arranged so as to face the glass plate 20 side so that the emission direction of the laser beam L emitted from the first to third sensor heads 10a, 10b, 10c can be finely adjusted. Via the box 18.
[0022]
In the case of the present embodiment, the first sensor head 10a is arranged at the center, and the second and third sensor heads 10b and 10c are arranged on both sides of the first sensor head 10a.
[0023]
In such an arrangement state of the sensor heads 10a, 10b, and 10c, the laser beams L emitted from the sensor heads 10a, 10b, and 10c are surfaces separated by a distance corresponding to the thickness of the casing 100 in the tunnel axis direction. However, since the thickness of the casing 100 is about several centimeters, it can be treated as substantially the same plane.
[0024]
The first sensor head 10a is provided with a window 101 so that the laser beam L is emitted obliquely upward, and the second and third sensor heads 10b and 10c have the laser beam L directed substantially in the horizontal direction. The window part 101 is installed so that it may be launched.
[0025]
As shown in FIG. 1, a box 18 containing three first to third sensor heads 10a, 10b, and 10c has a laser beam on one end side of an excavation cross section 22 such as a tunnel for measuring internal displacement. It is fixedly installed immediately after excavation so that L is fired toward the other side of the excavation section 22.
[0026]
The three first to third reflection sheets 12a, 12b, and 12c are attached to the high-efficiency reflection plate 120, and the first and second reflection sheets 12a and 12b face the back side of the ceiling portion of the excavation section 22. In this way, it is installed with an inclination at a predetermined inclination angle.
[0027]
Further, the third reflection sheet 12 c is installed on the opposite side of the excavation section 22 where the box 18 is installed and so as to face the box 18. In the vicinity of the third reflection sheet 12c, the received laser beam L is reflected toward the second reflection sheet 12b, and the laser beam L reflected by the second reflection sheet 12b is reflected toward the box 18 side. A prism 24 is installed.
[0028]
The prism 24 may be a reflecting mirror. The first sensor head 10a accommodated in the box 18 has a window portion after the laser beam L emitted from the window portion 101 irradiates the first reflection sheet 12a and is reflected by the first reflection sheet 12a. In order to return to 101, the emission direction of the laser beam L and the inclination angle of the reflection surface of the first reflection sheet 12a are adjusted.
[0029]
Also in the second sensor head 10b, the laser beam L emitted from the window portion 101 is received by the prism 24, the laser beam L emitted from the prism 24 irradiates the second reflective sheet 12b, and the second After the light is reflected by the reflection sheet 12b, the emission direction of the laser beam L and the inclination angles of the reflection surfaces of the prism 24 and the second reflection sheet 12b are adjusted so as to return to the window portion 101 through the prism 24.
[0030]
Further, similarly, in the third sensor head 10c, after the laser beam L emitted from the window portion 101 irradiates the third reflection sheet 12c and is reflected by the third reflection sheet 12c, In order to return, the emission direction of the laser beam L and the inclination angle of the reflection surface of the third reflection sheet 12c are adjusted.
[0031]
The control unit 14 is electrically connected to each of the sensor heads 10a, 10b, and 10c, controls the operation of each of the sensor heads 10a, 10b, and 10c, and the corresponding reflection sheet from each of the sensor heads 10a, 10b, and 10c. The laser beams LL are emitted to 12a, 12b, and 12c, respectively, and the reflected laser beams are individually received, so that the corresponding reflections from the sensor heads 10a, 10b, and 10c are based on the phase difference between the emitted and received laser beams. Distances to the sheets 12a, 12b, 12c, that is, a distance a between the first sensor head 10a and the first reflection sheet 12a, a distance b between the second sensor head 10b and the second reflection sheet 12b, and a third sensor A distance c between the head 10c and the third reflection sheet 12c is calculated.
[0032]
The personal computer 16 electrically connected to the control unit 14 stores the distances a, b, and c obtained by the control unit 14 at predetermined time intervals and displays the results on a monitor.
[0033]
For the measurement of the distances a, b, c as described above, when the sensor heads 10a, 10b, 10c and the reflection sheets 12a, 12b, 12c are installed, for example, a sampling time of about 10 minutes to 60 minutes is set. During this sampling time, it is continuously performed automatically.
[0034]
When the distances a, b, and c between three different points on the excavation section 22 are continuously obtained, the internal displacement of the excavation section 22 can be obtained from the principle of triangulation.
[0035]
Now, according to the method for measuring the internal displacement of the excavation cross section configured as described above, three sensor heads 10a, 10b, 10c are installed on one end side of the excavation cross section 22, and the other end of the excavation cross section 22 is provided. Three reflection sheets 12a, 12b, and 12c that are provided on the side and the ceiling and individually reflect the laser beams L emitted from the sensor heads 10a, 10b, and 10c are installed. , 10c to the corresponding reflecting sheets 12a, 12b, 12c, respectively, and individually receiving the reflected laser beams, the corresponding reflecting sheets 12a, 12b, 12c are received from the sensor heads 10a, 10b, 10c. By calculating the distances a, b, and c, the empty displacement of the excavation cross section 22 is obtained, so that the cross section displacement immediately after excavation can be measured.
[0036]
In addition, since the distances a, b, and c are continuously measured by continuously emitting the laser beam L from the sensor heads 10a, 10b, and 10c, the laser beam L is interrupted by the movement of heavy equipment. Even if it is done, when this shut-off state is released, it becomes possible to measure immediately, and since there is no human work in recovering such measurement, there is no problem in safety.
[0037]
In the case of the present embodiment, when a large displacement occurs in the inner space of the excavation section 22 being measured, the inclined state of the reflection sheets 12a, 12b, 12c is greatly displaced, and the sensor heads 10a, 10b, It is predicted that the laser beam L emitted from 10c will not accurately irradiate the reflection sheets 12a, 12b, and 12c, and as a result, the distances a, b, and c may not be measured. On the contrary, when the distances a, b, and c cannot be measured in this embodiment, it is detected that a very large internal air displacement has occurred.
[0039]
【The invention's effect】
As described above in detail in the embodiment, according to the method for measuring the internal displacement of the excavation cross section according to the present invention, safety is ensured and initial measurement immediately after excavation is performed while avoiding complicated work. It becomes possible.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a measurement state showing an embodiment of a measurement method according to the present invention.
FIG. 2 is an enlarged view of a main part of FIG.
FIG. 3 is a front view of FIG. 2;
FIG. 4 is an explanatory diagram of a conventional method for measuring an internal air displacement.
FIG. 5 is an explanatory diagram of a conventional method for measuring an internal air displacement.
[Explanation of symbols]
10a, 10b, 10c Sensor head 12a, 12b, 12c Reflective sheet 14 Control unit 16 Personal computer 18 Box 20 Glass plate 22 Drilling section 24 Prism

Claims (1)

First to third sensor heads that are fixedly installed on one end side of the excavation cross section to be measured, emit a laser beam toward the other end side of the excavation end surface, and receive reflected light of the emitted laser beam; ,
A pair of first and third reflection sheets that are provided on the other end side and the ceiling of the excavation cross section and reflect a laser beam emitted from the sensor head;
By constantly irradiating a laser beam from the first and third sensor heads to the first reflecting sheet on the ceiling and the third reflecting sheet on the other end side to receive the reflected laser beam. , Calculation of distance measurement from the first and third sensor heads to the corresponding first and third reflective sheets, and
A laser beam is always applied to the second reflection sheet provided on the ceiling through a reflecting member such as a prism provided on the other end side from the second sensor head, and the reflected laser beam is received. Accordingly, continuously performed and a calculation of the distance measurement between from the second sensor head to the second reflecting sheet, a device and a control unit that stores the distance measurement values obtained at predetermined time intervals Use
The wavelength of the laser beam is selected according to the size of the distance,
By constantly measuring the distance from the first to third sensor heads to the first to third reflecting sheets disposed on substantially the same plane corresponding to each of the first to third sensor heads, A method for measuring an internal displacement of an excavated cross section characterized by obtaining a displacement.

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