JPH102184A - Geological exploration method and system in front of tunnel face - Google Patents

Abstract

(57) [Summary] [Problem] To accurately detect a geologically changed surface in front of a tunnel face. Kind Code: A1 In a geological exploration ahead of a tunnel face by a radar, a method or a system for superposing a plurality of waveforms of received waves from the geology ahead of the face to obtain a combined received waveform and exploring the geology ahead of the face from the combined received waveform. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a geological survey in front of a tunnel face.

[0002]

2. Description of the Related Art In a shield machine or a tunnel boring machine, when the condition of the ground to be excavated deteriorates,
Sometimes excavation is impossible, and the restoration requires a great deal of labor and money.

[0003] However, although a search using an electromagnetic radar has been conventionally performed, a weak reflected wave cannot be detected, and it simply searches for an obstacle such as a ready-made pile or a structure. Directly on the screen.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to accurately search for a geological change surface in front of a tunnel face.

[0005]

According to the present invention, there is provided a method for detecting geology ahead of a tunnel face by using a radar, wherein a plurality of transmitted waves are transmitted in a geology ahead of the face and a plurality of received waves are received.
Obtain a composite received waveform by superimposing the waveforms of a plurality of received waves, characterized by exploring the geology in front of the face from the composite received waveform, in the tunnel face front geological exploration method, or in the tunnel face front geological exploration method Calculates the composite reception waveform for each radar measurement position, displays the composite reception waveforms side by side on the same plane so that the radar measurement positions of each composite reception waveform match, and searches for the geology ahead of the face. In the geological exploration method in front of the tunnel face, or in the geological exploration method in front of the tunnel face, a composite reception waveform is obtained for each radar measurement position, and the radar measurement position of each composite reception waveform is shifted to obtain each composite reception waveform. A geological exploration method in front of the tunnel face, or a cutter face, characterized in that they are displayed side by side on the same plane so that In the geological survey system ahead of the tunnel face by radar for the face of the tunnel to be excavated by a machine having a machine, an antenna is mounted on the cutter face surface, and the antenna transmits the transmitted wave of the electromagnetic wave several times in the geology ahead of the face by the antenna, and is reflected. A processing device that receives the received plurality of received waves and processes the waveform of the received wave, and an output device that displays the processed waveform of the received wave, and the processing device superimposes and synthesizes the waveforms of the plurality of received waves. Finding the received waveform, displaying the combined received waveform superimposed on the output device, characterized by exploring the geology in front of the face, in the tunnel face front geological exploration system, or in the tunnel face front geological exploration system, Geological survey system in front of tunnel face, transmitting and receiving from an antenna while the face is rotating Or, in the tunnel face forward geological prospecting system, the antenna is characterized in that separate the originating antenna and receiving antenna, tunnel face forward geological exploration system, or,
In the geological survey system in front of the tunnel face, a combined reception waveform is obtained for each measurement position of the radar, and the combined reception waveforms are displayed side by side on the same plane of the output device so that the measurement positions of the radars of the combined reception waveforms match. In the geological exploration system in front of the tunnel face, characterized by exploring the geology in front of the face, or in the geological exploration system in front of the tunnel face, a composite received waveform is obtained for each position in the direction orthogonal to the face of the electromagnetic radar. , By shifting the measurement position of the radar of each composite received waveform, displaying them side by side on the same plane of the output device so as to match each composite received waveform, and exploring the geology ahead of the face of the tunnel, In the exploration system.

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

<A> Geological Survey System Ahead of the Tunnel Face The geological survey system ahead of the tunnel face is such that an antenna of an electromagnetic radar is arranged on a cutter face of a shield machine 1 or a tunnel boring machine, etc. A radar signal (transmitted wave) is transmitted in the ground, and a received wave reflected from the ground and returned is received, and waveform processing is performed.

The antenna uses, for example, a resonance frequency of about 100 MHz, and a dual-purpose antenna 3 for both transmission and reception as shown in FIG. 1 or a transmission antenna 4 and a reception antenna 5 as shown in FIG. May be done.

As shown in FIG. 3, the geological survey system in front of the tunnel face is provided with a transmission signal from a transmission circuit 11 to an antenna 10 to transmit a radar signal, and a reception signal received by the antenna 10 is received by a reception circuit 12 to receive a reception signal. And input it to the computer 14 via the electromagnetic radar body 13. The computer 14 performs signal processing, stores necessary data such as a received waveform, and outputs the data to an output device 15 such as a display device or a printing device.

<B> Transmitting and Receiving For example, a radar signal of an electromagnetic wave pulse is transmitted from the antenna 10 at regular time intervals, reflected at various points such as the boundary 6 of the stratum in front of the face, and the reflected wave is reflected by the antenna. 10
To receive.

By adjusting the transmission interval of the radar signal, a large number of transmissions can be performed while the cutter face 2 makes one rotation, so that a large number of reception waves can be received and a reception waveform can be recorded.

<C> Overlapping process The received wave includes a noise 21 as well as a reflected wave 20 that is reflected at various places with different media such as the boundary surface 6 of the stratum. FIG. 4 shows a waveform of a received wave obtained while the cutter face 2 makes one rotation. The waveforms of these reception waves show the waveforms of the respective reception waves when the radar signal is transmitted many times when the cutter face surface (the antenna position) is almost at the same position (X1).

FIG. 5 shows a composite reception waveform obtained by superimposing the waveforms of these reception waves (a composite waveform of the added reception waves). By performing the superimposition processing, the noise 21 is generated at random positions and thus is weakened, and the reflected wave 20 is present in any of the received waves and thus is emphasized. As a result, only the reflected wave 20 can be obtained.

<D> Reception at Different Cutter Face Positions The cutter face 2 is rotated to excavate, and a composite reception waveform of the reception wave at each excavation position is shown in FIG. Instead of the composite reception waveform, the waveform of the reception wave can be used simply.

The signal in the upper part of FIG. 6 is a composite reception waveform when the cutter face position is X1, and the signal in the next step is a composite reception waveform when the cutter face position advances by ΔX. The signal at the stage is a combined reception waveform when the cutter face position has advanced by nΔX. From these combined reception waveforms, it is understood that the position of the reflected wave 20 on the stratum boundary 6 is approaching as the excavation of the machine proceeds. In addition, the waveform included in any of these signals indicates that a reflective substance is present in front regardless of the measurement position.

FIG. 7 shows a case in which the same reflected wave is corrected so as to match the same time axis position in each signal so that the signal in FIG. 6 can be easily viewed. That is, as the reflected wave 20 from the same place appears earlier as the cutter face position advances, the cutter face position at the time of radar transmission of each signal is corrected to be the same position,
The same reflected waves are arranged and displayed at the same time. The synthesized reception waveform obtained in this way is
VSP (Vertical Seism) implemented in the field of oil exploration
ic Profiling). Therefore, V
Processing such as filtering, speed filtering, deconvolution, and migration performed by the SP can be applied. Therefore, the condition of the formation can be more easily identified.

[0017]

According to the present invention, the following effects can be obtained. <a> By repeating the transmission and reception of the radar at the same position, adding the waveforms of a large number of these received waves, and obtaining a synthesized received waveform, noise can be removed. <B> Repeated transmission and reception of radar at a position shifted by ΔX,
By displaying the waveforms of these received waves side by side, a weak reflected wave can be easily detected, and thereby a geological boundary surface can be accurately searched. <C> By simultaneously processing the waveform groups of the received waves at positions shifted by ΔX, it is possible to search for a geological boundary surface at a farther position.

[Brief description of the drawings]

Fig. 1 Geological exploration map in front of a face by radar

FIG. 2 is a geological exploration map in front of the face, which distinguishes the transmitting and receiving antennas.

FIG. 3 is a block diagram of a geological survey system in front of a face;

FIG. 4 is a reception waveform diagram at the same cutter face position.

FIG. 5 is a superimposed reception waveform diagram in which reception waveforms are added.

FIG. 6 is a reception waveform diagram at different cutter face positions.

FIG. 7 is a correction diagram of a reception waveform at different cutter face positions.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Shield machine 2 ... Cutter face 3 ... Combined antenna 4 ... Transmitting antenna 5 ... Receiving antenna 6 ... Boundary surface of stratum 7 ... Tunnel 10 Antenna 11 Transmitting circuit 12 Receiving circuit 13・ Radar body 14 ・ Computer 15 ・ Output device 20 ・ Reflected wave 21 ・ Noise

Claims (8)

[Claims] 1. A method for detecting geology ahead of a tunnel face by using a radar, comprising: transmitting a plurality of transmitted waves in a geology ahead of the face, receiving a plurality of received waves, and superimposing waveforms of the plurality of received waves; A geological exploration method in front of the tunnel face, which is characterized by searching for the geology ahead of the face from the combined reception waveform. 2. A geological survey method in front of a tunnel face according to claim 1, wherein a composite reception waveform is obtained for each radar measurement position, and each composite reception waveform is determined so that the radar measurement position of each composite reception waveform matches. A geological exploration method in front of a tunnel face, which is displayed side by side on the same surface and explores geology in front of the face. 3. The geological survey method in front of a tunnel face according to claim 1, wherein a composite reception waveform is obtained for each radar measurement position, and the radar measurement position of each composite reception waveform is shifted to match each composite reception waveform. A geological exploration method in front of a tunnel face, which is displayed side by side on the same plane and the geology in front of the face is explored. 4. A geological exploration system in front of a tunnel face using a radar for a face of a tunnel excavated by a machine having a cutter face, wherein an antenna is mounted on the face of the cutter face, and the antenna is used to generate electromagnetic waves several times in the geology ahead of the face. A processing device for transmitting a transmission wave, receiving a plurality of reflected reception waves, processing a waveform of the reception wave, and an output device for displaying a waveform of the processed reception wave; A geological exploration system in front of a tunnel face, characterized in that a superimposed waveform is obtained to obtain a synthesized received waveform, the synthesized received waveform superimposed by an output device is displayed, and geology in front of the face is searched. 5. The geological survey system in front of a tunnel face according to claim 4, wherein transmission and reception are performed from an antenna while the cutter face is rotating. 6. The geological exploration system in front of a tunnel face according to claim 4, wherein the antenna is divided into a transmitting antenna and a receiving antenna. 7. The geological survey system in front of a tunnel face according to claim 4, wherein a composite reception waveform is obtained for each radar measurement position, and each composite reception waveform is determined so that the radar measurement position of each composite reception waveform matches. A geological exploration system in front of a tunnel face, which is displayed side by side on the same surface of an output device to search for geology in front of the face. 8. The geological survey system in front of a tunnel face according to claim 4, wherein a composite reception waveform is obtained for each position in a direction orthogonal to the face of the electromagnetic radar, and the radar measurement position of each composite reception waveform is shifted. A geological exploration system in front of a tunnel face, which is displayed side by side on the same surface of the output device so as to match the respective combined reception waveforms and explores geology in front of the face.