JP2620032B2 - Ground collapse detection device in shield method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a collapse of a ground in a shield method.

[0002]

2. Description of the Related Art When a tunnel is constructed using a shield machine, when the shield machine excavates, a gap may be generated between the skin plate of the shield machine and the ground due to collapse of a face portion. Or collapse.

[0003]

In order to detect such a collapse of the face, there is an energized electrode type detecting device in which an electrode is provided on a skin plate near the cutter head of the shield machine or an outer peripheral portion of the cutter head. With the current-carrying electrode type detection device, depending on the soil condition, it may be difficult to determine the presence or absence of a void in the ground, or it may not be possible to determine the magnitude of the collapse. In many cases, a tunnel is constructed without using such a detecting device.

[0004] The present invention has been made in view of such a problem, and an object of the present invention is to provide a detection device capable of detecting collapse of a ground due to excavation of a shield machine.

[0005]

In order to achieve the above-mentioned object, the present invention provides an ultrasonic transmitter provided at a front portion of a shield machine for transmitting ultrasonic waves, and an ultrasonic transmitter which emits ultrasonic waves. An ultrasonic receiving means for receiving the ultrasonic wave reflected by the ground collapse surface, and a means for recognizing the shape of the ground collapse surface based on the output signal of the ultrasonic receiving means, It is a detection device.

[0006]

According to the present invention, an ultrasonic wave is transmitted from the front of the shield machine, an ultrasonic wave reflected on the ground collapse surface is received, and the shape of the ground collapse surface is recognized based on the received signal.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of a front part of a shield machine provided with a landfall detection device according to one embodiment of the present invention, FIG. 2 is a schematic side view of the front part of the shield machine 1, and FIG. It is a front view of No. 3. A cutter face 3 is provided on the front surface of the shield machine 1, and the cutter machine 3 excavates while the cutter face 3 rotates about a rotation axis 10. 5 represents a skin plate. The cutter face 3 is provided with four ultrasonic sensors 7a, 7b, 7c and 7d, and the skin plate 5 is provided with two ultrasonic sensors 7a, 7b, 7c and 7d.
e, 7f are provided. These ultrasonic sensors 7a to 7
f transmits an ultrasonic wave and receives the ultrasonic wave reflected on the ground collapse surface. Ultrasonic waves are emitted from the ultrasonic sensor 7a so as to go vertically upward. Then, as shown in FIG. 2, the ultrasonic sensors 7b, 7c, and 7d emit ultrasonic waves forward every 20 degrees. Ultrasonic waves are emitted vertically upward from the ultrasonic sensors 7e and 7f. Reference numeral 9 denotes a rotation angle detector that detects the rotation angle of the rotation shaft 10.

FIG. 4 is a view showing a state of the shield machine 1 and the ground, and FIG. 5 is an enlarged view of a part of FIG. In FIG. 4, reference numeral 11 denotes a collapsed surface, and reference numeral 13 denotes a collapsed portion, which is a portion where the ground is loosened and muddy water is mixed in the shield method.

FIG. 6 is a block diagram showing a hardware configuration of the landfall detection device. Multiplexer 2
1, the ultrasonic sensors 7a to 7f are connected, and the multiplexer 21 switches the ultrasonic sensors 7a to 7f at high speed.
The ultrasonic transceiver 23 transmits an ultrasonic signal, and the ultrasonic signal is transmitted to the ultrasonic sensors 7a to 7a by the multiplexer 21.
The ultrasonic waves are transmitted to the ground sensor 7f, and are emitted from the ultrasonic sensors 7a to 7f toward the ground collapse surface.

When the ultrasonic sensors 7a to 7f receive the ultrasonic waves reflected on the ground collapsed surface, the ultrasonic transceiver 2
3 processes the signals sent from the ultrasonic sensors 7a to 7f, and converts the signals as shown in FIG.
Send to The signal processing board 25 performs the processing described later, and calculates the distance between each of the ultrasonic sensors 7a to 7f and the ground collapse surface. The controller 27 switches the multiplexer 21 according to an instruction from the personal computer 29. The personal computer 29 is based on the distance between each of the ultrasonic sensors 7 a to 7 f sent from the signal processing board 25 and the ground collapse surface and the rotation angle of the cutter face 3 sent from the rotation angle detector 9. To recognize the state of the collapsed part.

Next, the processing procedure of the signal processing board 25 will be described with reference to the waveform diagram of FIG. FIG. 7A shows a waveform of a reception voltage sent from the ultrasonic transceiver 23 to the signal processing board 25. The signal processing board 25 rectifies this (rectified waveform in FIG. 7B). Further, a plurality of measured waveforms are added and averaged (FIG. 7C).
Such averaging is performed for the following reason.
In the collapse part 13, since the floating matter does not stay at the same place, the position of the reflected signal from the floating matter varies. On the other hand, the reflected signal from the collapsed surface 11 can be detected at the same position, and thus the influence of the reflected signal from a floating object or the like can be removed by averaging the reflected signals.

Further, an effective range is extracted from the averaged waveform (FIG. 7 (d)). This sets the physical effective range of the received signal in consideration of the mounting position of the ultrasonic sensors 7a to 7f with respect to the shield machine 1. Then, the maximum value of the waveform within the effective range is detected, and the time Tm at that time is detected (FIG. 7 (e)). Further, the distance from the ultrasonic sensor 7 to the collapse surface is calculated by the following equation using the ultrasonic wave propagation velocity v in the muddy water and the time Tm.

Distance = (Tm · v) / 2 In this case, the ultrasonic wave propagation velocity v is determined by two ultrasonic sensors for calibration in muddy water collected from the chamber.
The ultrasonic waves are disposed so as to face each other, and the time during which the ultrasonic wave propagates through a certain distance is actually measured.

The personal computer 29 uses the distance between the ultrasonic sensors 7a to 7f sent from the signal processing board 25 and the collapsed surface 11 and the rotation angle sent from the rotation angle detector 9 as shown in FIG. 13 is displayed.

This processing is performed as follows. That is, the ultrasonic sensor 7 at a certain moment as follows:
Signals representing the rotation angles a to 7f are sent to the personal computer 29.

Ultrasonic sensor Elevation angle Rotation angle 7a 90 degrees 0 degrees 7b 70 degrees 10 degrees 7c 50 degrees 20 degrees 7d 30 degrees 30 degrees 7e 90 degrees 0 degrees 7f 90 degrees 0 degrees Also at another moment as follows: Ultrasonic sensors 7a-
A signal representing the rotation angle of 7f is sent to the personal computer 29.

Ultrasonic sensor Elevation angle Rotation angle 7a 90 degrees -10 degrees 7b 70 degrees 0 degrees 7c 50 degrees 10 degrees 7d 30 degrees 20 degrees 7e 90 degrees 0 degrees 7f 90 degrees 0 degrees As described above, the personal computer 29 includes: A signal indicating the rotation angle is sent every time, and a signal indicating the distance between the ultrasonic sensors 7a to 7f and the collapsed surface is sent from the signal processing board 25, and the personal computer 29 raises and lowers the ultrasonic sensors 7a to 7f. 8 by using the angle, the rotation angle, and the distance between the ultrasonic sensors 7 a to 7 f and the collapsed surface 11.
Then, a sectional view of the collapsed portion 13 as shown in FIG. 9 is displayed, and a bird's-eye view of the collapsed surface 11 as shown in FIG.

As described above, in the present embodiment, the cross section display and the bird's eye view display of the ground collapse surface 11 can be performed, and the state of collapse and the magnitude of the collapse can be grasped quantitatively. In addition, the collapsed surface 1
It is possible to easily determine the reflected signal from 1 and noise. That is, if the level of the reflected signal at the collapsed surface 11 is slightly higher than the noise, all measurements can be performed, and
/ N ratio is improved.

In the embodiment described above, four ultrasonic sensors are attached to the cutter face 3 and the skin plate 5
Although the example in which two ultrasonic sensors are attached to the first embodiment has been described, the attachment positions, the number of attached ultrasonic sensors, and the radiation directions of the ultrasonic sensors are not limited to those described in the present embodiment.

[0020]

As described above in detail, according to the present invention, it is possible to quantitatively grasp the state of collapse of the ground and the magnitude of the collapse.

[Brief description of the drawings]

FIG. 1 is a perspective view of a front part of a shield machine 1.

FIG. 2 is a schematic side view of the front part of the shield machine 1.

FIG. 3 is a front view of the cutter face 3;

FIG. 4 is a diagram showing the state of the shield machine 1 and the ground;

FIG. 5 is a partially enlarged view of FIG. 4;

FIG. 6 is a block diagram illustrating a hardware configuration of a device for detecting a collapsed ground surface according to the present embodiment.

FIG. 7 is a diagram showing a waveform of a signal processed in the signal processing board 25;

FIG. 8 is a sectional view of a collapsed portion obtained by a personal computer 29;

FIG. 9 is a bird's-eye view of a collapsed surface obtained by the personal computer 29;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Shield machine 3 ... Cutter face 5 ... Skin plate 7a-7f ... Ultrasonic sensor 9 ... Rotation angle detector 21 ... Multiplexer 23 ... Ultrasonic transceiver 25 ... Signal processing board 27 ... Controller 29 Personal computer

Claims (2)

(57) [Claims] 1. An ultrasonic wave transmitting means provided at a front portion of a shield machine for transmitting ultrasonic waves, and an ultrasonic wave receiving means for receiving ultrasonic waves emitted from the ultrasonic wave transmitting means and reflected on a ground collapse surface An ultrasonic transmitter based on an output signal of the ultrasonic receiver
A signal processing means for calculating a distance between the step and the ground collapse surface; a distance between the ultrasonic wave transmitting means and the ground collapse surface;
Shape of ground collapse surface based on elevation angle and rotation angle of means
Means for three-dimensionally creating and displaying the data, wherein the signal processing means adds and averages a plurality of measured waveforms
Detector for landslide in shield method including procedure
Place. 2. The ultrasonic transmitting means according to claim 1, wherein a plurality of said ultrasonic transmitting means are provided on a cutter face of said shield machine, and radiation directions of ultrasonic waves transmitted from each ultrasonic transmitting means are different from each other. Ground fall detection device in the shield method.