JPH11337652A - Seismic center device for geology prospecting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend a prospecting range, and to propagate an elastic wave with proper amplitude to prospecting a natural ground. SOLUTION: A seismic center device for geology prospect measures the reflection wave or the refraction wave due to the prospecting ground of an elastic wave which is generated from a seismic center device 4 for prospecting the geology of a natural ground. The device is provided with a metal small-gauge wire 8 that is arranged in an earthquake-generating container 6 and is quickly dissolved and vaporized by electric energy being quickly supplied, an explosive substance 9 that is filled into the earthquake-generating container 6 and is exploded by dissolving and vaporizing the metal small-gauge wire 8, and a supply device for supplying the electric energy to the metal small-gauge wire 8. When the amplitude of the elastic wave in the prospecting natural ground is set to A, distance from a seismic center position to the prospecting natural ground is set to L, a coefficient regarding the amplitude A of the elastic wave and the distance L is set to α, a coefficient regarding the distance of the elastic wave is set to n, and a coefficient regarding the capacity and amplitude of the explosive substance is set to m, the capacity QA of the explosive substance is represented by as QA=[(A×L<n> )/α]<1/n> . In this case, the coefficient α should be set to 770<=α<=4,000, and an attenuation coefficient n should be set to 1<=n<=3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic source apparatus for generating an elastic wave using electric energy as an epicenter by a geological exploration method at the time of constructing a tunnel or the like.

[0002]

2. Description of the Related Art Generally, in the case of work that requires excavation of ground, such as tunnel construction, it is necessary to search for geological changes that affect the construction in advance. Conventionally, there is an exploration method called elastic wave exploration method, in which blasting is performed, for example, on the side wall of a tunnel, and the elastic waves generated at that time are crushed zones or geological change surfaces, that is, changes in elastic wave velocity. It receives the elastic wave reflected or refracted from the surface and returns, and explores the geology ahead. However, this method has a problem that blasting operation with explosives involves danger.

[0003] Therefore, it has been proposed to use an electric discharge breakdown device that melts and vaporizes a metal or the like by electric energy instead of explosive explosive at the epicenter, and generate an elastic wave by the expansion impact force.

[0004]

However, in the above-described discharge breakdown device, the propagation range of the elastic wave generated by the impact force is narrow, the search range is limited, and the searchable range (distance) cannot be accurately grasped. However, there was a problem that the required exploration range could not be covered. An object of the present invention is to solve the above problems and to provide a geological exploration hypocenter apparatus capable of expanding an exploration range and propagating an appropriate elastic wave to the exploration range.

[0005]

[MEANS FOR SOLVING THE PROBLEMS]
The invention of claim 1 propagates the exploration ground to determine
And the reflected or refracted wave is measured.
A geological exploration source device for exploring the geology of
Vibration container and placed in this container to supply in a short time
Is rapidly melted and vaporized by the electric energy
Dissolves the vaporized material and the molten
Explosive substances that explode or burn rapidly due to vaporization
And electricity for supplying electrical energy to the molten vaporized material.
Equipped with an energy supply device,
Amplitude is A, distance from epicenter to exploration ground is L, elasticity
The coefficient relating to the wave amplitude A and the distance L is α, and the attenuation coefficient of the elastic wave is
Where n is the number and m is the coefficient for the volume and amplitude of the explosive substance.
The explosive substance volume Q _ATo Q_A= [(A × Lⁿ)
/ Α]^{1 / m}And this coefficient α is defined as 770 ≦ α ≦ 4000
The damping coefficient n is set to 1 ≦ n ≦ 3.

[0006] According to the above configuration, an explosive substance that is exploded or burned at a high speed by melting and vaporizing the molten vaporized substance by electric energy is used, so that a larger impact force can be obtained and the exploration range can be expanded. In addition, it is possible to generate appropriate elastic waves with the minimum necessary volume of explosive substances, so that it is possible to work safely without generating unnecessarily large impact force and to reduce running costs. Can be.

[0007] According to a second aspect of the invention, in the above configuration, when the amplitude of the acoustic wave necessary for exploration areas mountains and B, and the capacity Q _B of explosive ^{materials, [(B × L 3)} / α] ^{1 / m}
≧ Q _B ≧ [(B × L) / α] In the range of ^{1 / m} , m is 0.6
6 ≦ m ≦ 0.75. According to the above configuration, by setting the volume of the explosive substance in the above range, the amplitude of the elastic wave necessary for the exploration ground can be secured, and accurate exploration can be performed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a geological exploration apparatus provided with a geological exploration hypocenter apparatus according to the present invention will be described below with reference to FIGS.
It will be described based on. As shown in FIGS. 1 and 2, this geological exploration device 1 includes a hypocenter device 4 mounted in a mounting hole 3 formed in a tunnel side wall 2, and an electric energy supply device (hereinafter simply referred to as an electric energy supply device) that supplies electric energy to the hypocenter device 4. 5), and an acceleration sensor (seismic receiver) 21 for detecting an elastic wave generated by the impact force of the hypocenter device 4 and reflected from the ground in the exploration range. .

The hypocenter device 4 includes a vibrating vessel 6 and a thin metal wire (for example, copper: Cu) which is a molten vaporized substance inserted into the vibrating vessel 6 and connecting a pair of electrodes 7 to each other. And an explosive substance 9 which is enclosed in the seismic vessel 6 and is exploded (including short-time combustion) by melting and vaporization of the fine metal wires 8 to transmit elastic waves to the ground by the impact force.
(For example, a nitro compound) 9.

The supply device 5 includes a capacitor 12 connected to a power supply 10 via an energy control circuit 11, and a discharge switch 13 for discharging electric energy charged and stored in the capacitor 12. By the way, the capacity Q _A of the explosive substance 9 and the amplitude A _{0 of the} elastic wave are A
₀ = α × Q _A ^m ... Here, α is a coefficient related to the elastic wave and the distance, and m is a coefficient related to the capacity and the amplitude, and is in the range of 0.66 ≦ m ≦ 0.75. Further, the amplitude of the elastic wave propagating in the ground is attenuated, and the attenuation is the distance L
(L ^-n : 1 ≦ n ≦ 3). Therefore, the amplitude A of the elastic wave at the distance L from the hypocenter device 4 to the search site is expressed as A = A ₀ × L ⁻ⁿ . Furthermore from equation and equation, and ^{_{A = α × Q A m ×}} L -n α = A / (Q A m × L -n) α = (A × L n) / Q A m ... Equation.

Further, the capacity Q _A explosive material 9 for obtaining a predetermined amplitude A of the acoustic wave in the distance ^{_{L, Q A m = (A ×}} L n) / α Q A = [(A × L n ) / Α] ^{1 / m} ... Next,
FIG. 3 shows the relationship between the distance L and the amplitude A obtained by the experiment. The explosive substance 9 used here is a nitro compound, m = 0.75, n = 1.5, Q _A = 140 (g)
From the equation, the coefficient α is given by α = (A ₀ × L
^-1.5 ) / 140 ^0.75 = 2500.

Accordingly, if the distance L to the search site and the amplitude A of the elastic wave required for the search are determined, the capacity of the explosive substance 9 can be obtained from the equation. Here, α = 2,500, but the coefficient m relating to the volume and amplitude of the explosive substance is selected in the range of 0.66 ≦ m ≦ 0.75, and the damping coefficient n is set in the range of 1 ≦ n ≦ 3. By selection, the range of numerical values determined from the equation, ie, 77
The coefficient α can be changed in the range of 0 ≦ α ≦ 4000, and preferably α = 2,500.

Next, the acceleration sensor 21SeismicSensitivity
Is the distance L in consideration of the background noise level.
The required amplitude B of the elastic wave is B ≦ α × Q_B ^m× L^-n=
A, and the attenuation coefficient n at the exploration ground is 1 ≦ n ≦ 3
Therefore, α × Q_B ^m× L^-3≦ B ≦ α × Q_B ^m× L^-1… Formula From the formula, the capacity Q of the explosive substance 9_BIs obtained, (α × Q_B ^m× L^-3) / B ≦ 1 ≦ (α × Q_B ^m× L^-1) / B α / (B × L^Three) ≦ 1 / Q_B ^m≦ α / (B × L) (B × L^Three) / Α ≧ Q_B ^m≧ (B × L) / α [(B × L^Three) / Α]^{1 / m}≧ Q_B≧ [(B × L) / α]^{1 / m}
..., where α = 2500 and the coefficient m is 0.66 ≦ m ≦
By setting it to 0.75, it is separated from the epicenter device 4 by the distance L.
Can be measured by the acceleration sensor 21
Of explosive substance 9 necessary to obtain a functioning elastic wave amplitude
Quantity Q_BIs requiredToTherefore, the volume of the explosive substance 9 is large.
Too bad for tunnels and running costs
Measurement is not too high, and on the contrary
Optimum volume Q of explosive substance 9 that does not become functional_BSearch for
Can be inspected. Here, the damping coefficient n is 1 ≦ n ≦ 3.
Range, but n <1 or ΔQ_B<[(B × L) /
α]^{1 / m}There is no soil that amplifies elastic waves at｝,
3 <n, that is, ｛[(B × L^Three) / Α]^{1 / m}<Q _BBullet in｝
This is because there is no soil that greatly attenuates sex waves.

FIG. 4 is a graph showing the range of the capacity Q of the explosive substance 9 suitable for exploration based on the equation. In addition,
The unit used here is the distance L (m), the amplitude A of the elastic wave (gal = cm / s ² ), and the units Q _A and Q _B of the explosive substance 9 are cc. When the geological exploration is performed by using the geological exploration apparatus 1 described above, the explosive substance 9 determined by the equation or the equation is used.
The seismic source device 4 filled with the capacity is mounted in the mounting hole 3, and the container 14 is filled with sand or the like, the supply device 5 is connected to the thin metal wire 8 via the electrode 7, and the required amount of electric energy is supplied to the capacitor 12. The discharge switch 13 is turned on in a state where the charge is accumulated, and electric energy is discharged and supplied to the thin metal wire 8 in an extremely short time. Then, the thin metal wire 8 is rapidly melted and vaporized and expanded, and the explosive substance 9 is exploded by the impact force at that time, and the seismic vessel 6 is destroyed. Waves are generated. The acceleration sensor 21 receives the reflected elastic wave which is reflected (or may be refracted) by the elastic wave at the crush zone or the geological change surface and is returned, thereby exploring the geological change ahead.

According to the above-described embodiment, elastic waves are generated not only by the impact force due to the melting and vaporization of the thin metal wires 8 but also by the explosive force of the explosive substance 9, so that the elastic waves having a large amplitude can be easily generated. Can be generated, and the operation can be performed safely. Further, by filling the capacity of the explosive substance 9 in the range obtained by the equation or the equation according to the distance L from the epicenter device 4 to the exploration ground, necessary for the elastic waves propagated to the exploration ground. The amplitude can be ensured, accurate exploration can be performed, and the running cost can be reduced without filling the explosive substance 9 more than necessary.

In the above-described embodiment, the acceleration sensor (seismic receiver) 21 detects the reflected elastic wave from the ground, but may be a refracted elastic wave.

[0017]

As described above, according to the first aspect of the present invention, since an explosive substance which explodes or burns at high speed by melting and vaporizing the molten vaporized substance by electric energy is used, a large impact force can be obtained. The exploration area can be easily expanded, and elastic waves can be generated with the minimum necessary volume of explosive material, so that it is possible to work safely without generating unnecessary large impact force. And the running cost can be reduced.

According to the second aspect of the present invention, by setting the volume of the explosive substance in the above range, it is possible to secure the amplitude of the elastic wave necessary for the exploration ground, and to perform accurate exploration. Become.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a geological exploration device including a geological exploration source device according to the present invention.

FIG. 2 is a cross-sectional view showing a state of use of the hypocenter apparatus for geological exploration.

FIG. 3 is a graph showing the relationship between the propagation distance and amplitude of an elastic wave in an experiment of the seismic source device.

FIG. 4 is a graph showing a required explosive substance capacity with respect to a distance to an exploration ground of the geological exploration source device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Geological exploration device 2 Tunnel side wall 3 Mounting hole 4 Hypocenter device 5 Electric energy supply device 6 Shock vessel 7 Electrode 8 Fine metal wire 9 Explosive substance 10 Power supply 11 Energy control circuit 12 Capacitor 13 Discharge switch 21 Acceleration sensor

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Imai 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Hironari Arai 1-7-7 Minami Kohoku, Suminoe-ku, Osaka-shi, Osaka No. 89 Inside Hitachi Zosen Corporation (72) Kazuya Sasaki, Inventor 1-7-7 Minami Kohoku, Suminoe-ku, Osaka City, Osaka Prefecture 89 Inside Hitachi Zosen Corporation (72) Hidehiko Maebata 1 Minami Kohoku, Suminoe-ku, Osaka Prefecture, Osaka No. 7-89 Hitachi Zosen Corporation

Claims (2)

[Claims] 1. A geological exploration source device for generating an elastic wave propagating in an exploration ground, measuring a reflected wave or a refracted wave thereof and exploring the geology of the ground, comprising: a seismic vessel; Molten vaporized material that is placed in a vibration container and is rapidly melted and vaporized by electric energy supplied for a short time, and explosiveness that is filled in the seismic container and exploded or rapidly burned by the molten vaporization of the molten vaporized material A material, and an electric energy supply device for supplying electric energy to the molten vaporized material, wherein the amplitude of the elastic wave at the exploration site is A, the distance from the epicenter to the exploration site is L, the amplitude of the elastic wave If the coefficient relating to A and the distance L is α, the damping coefficient of the elastic wave is n, and the coefficient relating to the capacity and amplitude of the explosive substance is m, the capacity Q of the explosive substance
_A is defined as Q _A = [(A × L ⁿ ) / α] ^{1 / m} , the coefficient α is set to 770 ≦ α ≦ 4000, and the attenuation coefficient n is set to 1 ≦ n ≦ 3. Hypocenter equipment. If the 2. A is B the amplitude of the acoustic wave necessary for exploration areas mountains, the capacity Q _B of explosive ^{materials, [(B × L 3)} / α] 1 / m ≧ Q B ≧ [( B × L) / α] ^{1 / m}
2. The hypocenter apparatus for geological exploration according to claim 1, wherein m is set to 0.66 ≦ m ≦ 0.75.