JP3883298B2 - Geophysical exploration method and apparatus by electric discharge destruction - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a physical exploration method and apparatus by electric discharge destruction that generates elastic waves using electric discharge destruction as an epicenter by the seismic exploration method in rocks, grounds, underwater, structures and the like during tunnel construction.
[0002]
[Prior art]
In general, in the case of work that requires excavation of natural ground, such as tunnel construction, it is necessary to explore in advance geological changes that affect the construction. Conventionally, this exploration method has been called an elastic wave exploration method. This method blasts on the side wall of a tunnel, for example. It receives the elastic waves that have been reflected or refracted by the surface, and explores the geology ahead. However, this method has a problem in that it is dangerous because the blasting work is performed with gunpowder.
[0003]
Therefore, instead of exploding explosives at the epicenter, it is proposed to use an electric discharge destruction device that uses the impact force generated by melting and vaporizing metals etc. with electrical energy and generating elastic waves with the expansion impact force Has been.
[0004]
[Problems to be solved by the invention]
However, the geophysical exploration method using electric discharge breakdown is based on the seismic source by receiving the refracted wave or reflected wave of the elastic wave due to the impact force generated in the soil or rock, and the attenuation or change of the measured waveform of the acceleration. In order to investigate the geological situation at a position away from the location, if the generation time of the impact force is not clear, the distance and position of the measurement waveform point cannot be determined, and there is a problem that accurate survey cannot be performed. In urban areas, the use of gunpowder may be restricted due to environmental considerations.
[0005]
An object of the present invention is to provide a geophysical exploration method and apparatus by electric discharge breakdown that can solve the above-mentioned problems and can accurately grasp the generation time of an impact force and perform an accurate physical exploration.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the physical exploration method by electric discharge destruction according to claim 1 propagates in the exploration material by an impact force when supplying electric energy to the conductive material of the hypocenter device in a short time to melt and vaporize. When an exploration material is probed by generating an elastic wave and detecting the reflected wave or refracted wave, the trigger switch turns on the discharge switch to supply electric energy to the metal thin wire that is a conductive material. The seismic source device from the start of the electrical energy supply obtained according to the electrical energy supply amount, which is a characteristic of the discharge condition, and the material, shape, and thickness of the fine metal wires that are the characteristics of the seismic device The impact force generation time is obtained by adding the delay time until the generation of the discharge impact force due to.
[0007]
The physical exploration device by electric discharge destruction according to claim 2 generates an elastic wave propagating in the exploration material by an impact force caused by electric discharge destruction when supplying electric energy to the conductive material in a short time to vaporize the conductive material. , A geophysical exploration device by electric discharge destruction that investigates the exploration material by measuring its reflected wave or refracted wave, and a thin metal wire as a conductive material is connected between the electrodes in the exploration vessel filled with the transmission material A seismic source device, an electrical energy supply device that supplies electrical energy to the fine metal wires of the seismic source device, a seismic detector that detects elastic waves generated from the seismic source device, and a vibration measurement based on the signal from the seismic device A vibration detection device, and a start detection line for outputting a trigger signal for operating a discharge switch of the electrical energy supply device to the vibration measurement device. And at the start of electric energy supply by the trigger signal from the startup detection line, the supply amount of electric energy is a characteristic of the discharge conditions, and characteristics made of thin metal wire which is of source device, the shape, corresponding to the thickness obtained The delay time from the start of electrical energy supply to the seismic source device to the generation of the discharge impact force is added to determine the impact force generation time.
[0008]
According to the above configuration, the trigger signal for turning on the discharge switch is taken out, the electric energy supply start time detected by the trigger signal, the amount of electric energy supplied as the characteristics of the discharge condition , the characteristics of the hypocenter device by experiment and simulation By adding the delay time obtained in advance corresponding to the material, shape, and thickness of the thin metal wire, the impact force generation time by the seismic source device can be accurately obtained, and accurate physical exploration becomes possible. .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Here, an embodiment of a geological exploration device by electric discharge destruction according to the present invention will be described based on the drawings.
[0010]
First, the basic configuration of the impact generator 10 that performs discharge breakdown will be described with reference to FIG. The impact generator 10 includes a seismic source device 1 mounted in a mounting hole formed in a target ground or rock, and an electrical energy supply device (hereinafter simply referred to as “supply device”) that supplies electrical energy to the seismic source device 1. ) 3.
[0011]
The seismic source device 1 is a thin metal wire (for example, carbon or the like, which is also referred to as a melt-vaporized material) that connects a pair of electrodes 1d inserted into the exploration container (cartridge) 1b (for example, carbon). Copper: Cu) 1a and a (pressure) transmission material 1c enclosed in the exploration vessel 1b and transmitting the impact force generated by the melting and vaporization of the thin metal wire 1a to the natural ground. However, instead of this water, it may be an explosive substance that explodes (including short-term combustion) by melt vaporization and transmits elastic waves to the natural ground by this impact force, such as a nitro compound. .
[0012]
The supply device 3 includes a capacitor 7 connected to a discharge power source 5 via a resistor 6 for energy control, and a discharge switch (thyristor) 8 for discharging electric energy charged and accumulated in the capacitor 7. I have. The discharge switch 8 is provided with a trigger circuit 9 for outputting a trigger signal for turning on / off the discharge switch 8 and connected to the discharge switch 8 via a trigger signal output line 11. 11a is a resistor for adjusting a trigger signal.
[0013]
As shown in FIG. 3A, the trigger circuit outputs a trigger signal for turning on the discharge switch 8 for a predetermined time from the activation time t0. Further, as shown in FIG. 3B, the electrical energy stored in the capacitor 7 is supplied to the fine metal wire 1 a of the earthquake source device 1 through the feeder line 13 by the discharge switch 8 turned on by this trigger signal. At this time, as shown in FIG. 3 (c), the discharge current flows and the thin metal wire 1a is melted at this peak time = t1, and the acceleration of the discharge impact force at this peak time t1 as shown in FIG. 3 (d). The peak value of appears. Therefore, the delay time T is from the time t0 when the trigger signal is output to t1 when the peak value of the acceleration of the discharge impact force appears. The delay time T varies depending on the discharge conditions, that is, the amount of electric energy supplied and the material, shape, and thickness of the thin metal wire 8. If these conditions are constant, it is understood that the delay time T is constant. Yes.
[0014]
FIG. 1 shows a first embodiment of a geological exploration apparatus according to the present invention. The same members as those in the basic configuration are denoted by the same reference numerals, and description thereof is omitted.
This geological exploration device is an acceleration sensor (seismic receiver) that detects a reflected elastic wave from a natural ground in the exploration range among the elastic waves generated by the impact force of the source device 1 in addition to the impact generation device 10 described above. 4 and a vibration measuring device 12 for detecting the vibration of the reflected elastic wave based on the detection signal of the acceleration sensor 4 are provided.
[0015]
Further, the trigger signal output line 11 is connected to an activation detection line 21 for taking out a trigger signal, and is connected so as to be input to the vibration measuring device 12. The vibration measuring device 12 detects the start of electric energy supply by this trigger signal. can do. In addition, since the electrical energy supply device 3 is a high voltage circuit, an insulator (DC-DC isolator) 22 for insulation is interposed in the activation detection line 21. Further, the vibration measuring device 12 has a delay time T from the trigger signal output point t0 to t1 where the peak value of the acceleration of the discharge impact force appears in advance according to the specifications of the hypocenter device 1 and the electric energy supply circuit 3. Have been entered.
[0016]
Therefore, when the trigger signal is output from the trigger circuit 9 and the discharge switch 8 is turned on, the electric energy stored in the capacitor 7 is supplied to the metal thin wire 1a of the source device 1, and the impact force due to the melt vaporization of the metal thin wire 1a. Is transmitted to the natural ground 2 through the transmitting substance 1c. Then, the reflected elastic wave from the natural ground 2 in this exploration range is detected by the acceleration sensor 4 and measured by the vibration measuring device 12. At this time, a trigger signal is input to the vibration measuring device 12 via the activation detection line 21. In the vibration measuring device 12, the input delay time T is added to the activation time t0 based on the trigger signal, and the impact force. Generation time t1 is obtained, and an elastic wave is analyzed based on the generation time t1 of the impact force to obtain a geological structure.
[0017]
According to the above embodiment, the trigger signal for turning on the discharge switch 8 is taken out to the vibration measuring device 12 and the seismic source device 1 is added to the electric energy supply start time t0 by adding the delay time T inputted in advance. It is possible to accurately obtain the impact force generation time t1 due to the above, and an accurate geological exploration becomes possible.
[0018]
FIG. 4 shows a second embodiment. In the first embodiment, the trigger signal is directly taken out. In the second embodiment, a relay 31 which is a switch means is interposed.
[0019]
That is, the relay 31 is interposed in the power output line 33 connected to the vibration measuring device 12 from the signal power source 32 incorporated in the electric energy supply device 3, and the trigger signal extracted by the activation detection line 21 is received. A drive power supply is input to the coil side of the relay 31, and a delay time T is added thereto.
[0020]
Therefore, when the relay 31 is turned on by the trigger signal, the activation signal (power voltage) is supplied from the signal power source 32 via the power output line 33 to the vibration measuring device 12 and the activation time is detected.
[0021]
According to the second embodiment, an effect similar to that of the first embodiment can be obtained. The signal power source 32 can also be incorporated into the vibration measuring device 12.
[0022]
FIG. 5 shows a third embodiment. In the third embodiment, the relay 31 of the second embodiment is an optically driven relay (photocoupler) 41 that is an optically driven switch operated by an optical signal such as an LED.
[0023]
That is, the light drive relay 41 is interposed in the power output line 33 connected to the vibration measuring device 12 from the signal power source 32 incorporated in the electric energy supply device 3. The activation detection line 21 is connected to an LED circuit (light signal conversion circuit) 42 of the light driving relay 41. Therefore, the trigger signal of the activation detection line 21 is converted into an optical signal by the LED circuit 42, and the optical drive relay 41 is turned on by this optical signal, so that the activation signal is transmitted from the signal power source 32 via the power output line 33. The delay time T is added to the operation time t0 of the discharge switch 8 and the generation time of the discharge impact force is detected.
[0024]
According to the above-described embodiment, in addition to the above operations and effects, the circuit of the power supply output line 33 is insulated from the high voltage circuit of the electric energy circuit device 3, so that the operation is safe. The signal power source 32 can be incorporated in the vibration measuring device 12.
[0025]
FIG. 6 shows a fourth embodiment. In the fourth embodiment, in the third embodiment, a light-driven discharge switch 51 composed of an element such as a light-driven thyristor is provided, and a trigger signal output line 56 is connected from the trigger circuit 54. The trigger signal output via the first LED circuit (light signal conversion circuit) 55A and the second LED circuit (light signal conversion circuit) 55B is converted into an optical signal. Then, the optical drive switch section 55a of the optical drive discharge switch 51 is operated and turned on by the optical signal of the first LED circuit 55A, and the optical drive relay 41 is turned on by the optical signal of the second LED circuit 55B.
[0026]
Therefore, when the trigger circuit 54 is turned on, the trigger signal is converted into an optical signal of the first LED circuit 55A, and the optical drive switch portion 55a of the discharge switch 51 is turned on by this optical signal, whereby the trigger power source 52 Is supplied to the light-driven discharge switch 51 via the trigger power supply line 53 and turned on. Further, the trigger signal is converted into an optical signal by the second LED circuit 55B, and when the optical drive relay 41 is activated (turned on) by this optical signal, an activation signal is supplied from the signal power source 32 to the vibration measuring device 12, and the optical drive is performed. The delay time T is added to the operation time t0 of the discharge switch 51 of the formula, and the generation time of the discharge impact force is detected.
[0027]
According to the above embodiment, in addition to the above operations and effects, the circuit of the power supply output line 33 and the circuit of the trigger signal are insulated from the high voltage circuit of the electric energy supply device 3, so that the operation is further safer.
[0028]
The signal power source 32 can also be incorporated into the vibration measuring device 12. Further, an optical signal issued from one LED circuit may be branched and introduced into the light-driven relay 41 and the light-driven discharge switch 51.
[0029]
In each of the above embodiments, the geological exploration device has been described, but the exploration target may be a rock mass or a large structure.
[0030]
【The invention's effect】
As described above, according to the present invention, the trigger signal for turning on the discharge switch is taken out, and the electric energy supply amount, which is a characteristic of the discharge condition , is determined by experiment and simulation at the electric energy supply start time detected by the trigger signal. By adding the delay time obtained in advance corresponding to the material, shape and thickness of the fine metal wire that is the characteristic of the seismic source device, the impact force generation time by the seismic source device can be accurately obtained, and accurate physical Exploration becomes possible.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a first embodiment of a geological exploration apparatus according to the present invention.
FIG. 2 is a configuration diagram showing an impact force generator of the geological exploration device.
3A to 3D are time charts when the switch is operated in the geological exploration apparatus of FIG. 2; FIG. 3A is a trigger signal; FIG. 3B is an on / off signal of a discharge switch; Is a graph showing the discharge current, and (d) is a graph showing the impact force.
FIG. 4 is a configuration diagram showing a second embodiment of a geological exploration device according to the present invention.
FIG. 5 is a configuration diagram showing a third embodiment of a geological exploration device according to the present invention.
FIG. 6 is a configuration diagram showing a fourth embodiment of a geological exploration device according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Seismic source apparatus 2 Ground mountain 3 Electric energy supply apparatus 4 Acceleration sensor 5 Discharge power supply 6 Resistor 7 Capacitor 8 Discharge switch 9 Trigger circuit 11 Trigger signal output line 12 Vibration measuring apparatus 21 Start-up output line 22 Insulator 31 Relay 32 Signal power supply 33 Power output line 41 Light-driven relay 42 LED circuit 51 Light-driven discharge switch 54 Trigger circuit 55A First LED circuit 55B Second LED circuit 56 Trigger activation line T Delay time

Claims (5)

Probing the exploration material by generating an elastic wave that propagates in the exploration material by the impact force when supplying electric energy to the conductive material of the hypocenter device in a short time and evaporating it, and detecting the reflected or refracted wave When doing
Turns on the discharge switch by the trigger signal and supplies electric energy to the thin metal wire that is a conductive substance.
The electric energy supply start time obtained by this trigger signal corresponds to the amount of electric energy supplied, which is the characteristic of the discharge condition, and the material, shape, and thickness of the metal thin wire that is the characteristic of the hypocenter device. A physical exploration method by electric discharge destruction characterized by adding the delay time from the start to the generation of the discharge impact force by the seismic source device to obtain the impact force generation time. An elastic wave propagating through the exploration material is generated by the impact force of electrical discharge when supplying electrical energy to the conductive material in a short time to vaporize it, and the reflected or refracted wave is measured to detect the exploration material. A geophysical exploration device using electric discharge destruction to explore,
An epicenter device in which a thin metal wire that is a conductive material is connected between electrodes in an exploration vessel filled with a transmission material , an electric energy supply device that supplies electric energy to the thin metal wire of the seismic source device, and the seismic source device A receiver that detects the generated elastic wave, and a vibration measuring device that measures vibration based on the signal of the receiver;
A start detection line for outputting a trigger signal for operating the discharge switch of the electrical energy supply device to the vibration measuring device;
When the electric energy supply is started by the trigger signal from the start detection line, the vibration measuring device is supplied with the electric energy supply amount which is a characteristic of the discharge condition, and the material, shape and thickness of the metal fine wire which is the characteristic of the hypocenter device. Geophysical exploration device by discharge breakdown, characterized by adding the delay time from the start of electrical energy supply to the seismic source device to the occurrence of the discharge impact force obtained to obtain the impact force generation time . A power output line connected from the signal power source to the vibration measuring device, and a switch means interposed in the power output line are provided,
The physical exploration device by discharge breakdown according to claim 2, wherein the switch means is turned on by a trigger signal of a start detection line. The switch means is an optical drive switch operated by an optical signal,
4. The physical exploration device by discharge breakdown according to claim 3, wherein an optical signal conversion circuit for operating an optical drive switch is provided in the startup output line. The discharge switch is a light-driven discharge switch operated by an optical signal,
The physical exploration device by discharge breakdown according to claim 4, wherein an optical signal conversion circuit for operating a light-driven discharge switch is provided in the trigger signal output line.

Images