Ground fracture detection method

Abstract

The invention discloses a ground fracture detection method, which comprises the following steps of moving a detection device along the ground at a constant speed to obtain deflection states of two transverse conductors, and judging the specific position of a to-be-detected object according to the deflection states of the two transverse conductors. Due to the fact that magnetic resistance can be generated due to the difference of magnetic permeability of various substances, the phenomenon of magnetic overflow or convergence is generated on the earth surface, and existence and distribution conditions of the ground fissures are determined by detecting geomagnetic anomalies. The abnormality is found by testing the change of induced electromotive force voltage generated when a conductor cuts a magnetic line of force.

Description

Technical Field

[0001] The present invention relates to the field of detection technology, and in particular to a method for detecting ground fissures. Background Art

[0002] Traditional ground fissure detection mainly relies on drilling rig sampling and using the method of stratigraphic comparison to make judgments. In fact, the theory of faults is introduced into ground fissures. The existing geophysical exploration methods have large errors and are not recognized by everyone. The latest method is to use ground penetrating radar. By receiving and analyzing the reflected electromagnetic wave signals, the abnormal response of the cracks on the radar image can be clearly presented, which is convenient for locating and analyzing the morphology of the cracks. Based on the current technical level, the detection depth is limited.

[0003] There is no effective and accurate method to detect underground cavities, especially those deeper than 5 meters. Summary of the invention

[0004] In order to solve the problems in the prior art, the present invention provides a method for detecting ground fissures.

[0005] Its main technical solutions are as follows: A method for detecting ground fissures comprises the following steps: The detection device is moved along the ground at a uniform speed to obtain the deflection state of the two transverse conductors, and the specific position of the object to be detected is determined according to the deflection state of the two transverse conductors; The detection device comprises: a transverse conductor, one end of which is fixed on a screw cap, a conductor handle is arranged perpendicular to the transverse conductor, and the upper part of the conductor handle is rotatably connected to the screw cap; A capacitor box is arranged on the transverse conductor, a capacitor is arranged in the capacitor box, and an input end and an output end of the capacitor are respectively connected to the conductor handle and the transverse conductor through wires to enhance the detection sensitivity.

[0006] Furthermore, when performing detection, the left hand and the right hand of the human body respectively hold a detection device, so that the two transverse conductors in the detection device are in a parallel state, and the left hand and the right hand of the human body respectively hold a detection device to form an electromagnetic induction conductor; Mark the initial detection position, then move at a constant speed on the ground along the initial detection position, and record the first position of the deflection when the two detection devices deflect; A plurality of different positions are selected at the first position based on the first position, and a detection device is respectively held by the left hand and the right hand of the human body to form an electromagnetic induction conductor to perform detection along the selected plurality of different positions to delineate the scope of the ground fissure.

[0007] Furthermore, when performing detection, the device moves at a constant speed on the ground along the initial detection position, records the first position of the deflection when the two detection devices deflect, continues to move at a constant speed until the deflection of the two detection devices disappears, records any second position when the deflection disappears, and then continues to move at a constant speed until the two detection devices deflect again; records the third position; uses the line between the first position, the second position and the third position as the approximate diameter of the detected ground fissure, and uses the center of the line as a reference to frame a detection circle with the distance of the line as the radius, and then selects several detection points on the detection circle, uses the left and right hands of the human body to hold a detection device respectively to form an electromagnetic induction conductor, and performs detection along several different detection points to delineate the range of the ground fissure.

[0008] Furthermore, the wire arranged on the conductor handle is connected in series with the body capacitor by touching the wire by human hand, thereby increasing the strength of the transverse conductor in cutting the magnetic flux lines.

[0009] Furthermore, when the detection device is moved at a uniform speed perpendicular to the direction of the object to be detected, when the edge of the ground fissure to be detected is detected, the transverse conductors in the two detection devices held by the left hand and the right hand attract each other to form a pendulum.

[0010] Furthermore, when the transverse conductors in the two detection devices held by the left and right hands attract each other to form a pendulum, the position of the person and the angle of the pendulum are recorded, and the specific position of the edge of the ground fissure is obtained by recording the position of the person's movement and the angle of the pendulum.

[0011] Furthermore, when a person holds the detection device, the left hand and the right hand of the human body respectively hold a detection device to form an electromagnetic induction conductor. At the same time, the human body is used as a body capacitor, and the wire set on the conductor handle through the human hand touch pattern makes the capacitor and the human body as a body capacitor connected in series, thereby increasing the strength of the transverse conductor in cutting the magnetic flux lines.

[0012] Furthermore, when detecting ground fissures, the horizontal section formed by the ground fissures is used as the detection interface.

[0013] Furthermore, the transverse conductor and the conductor handle are both made of copper.

[0014] This application uses the stability of the natural geomagnetic field. Due to the difference in magnetic permeability of various materials, magnetic resistance will be generated, resulting in magnetic overflow or convergence on the surface. The presence and distribution of ground fissures are determined by detecting geomagnetic anomalies. This anomaly is discovered by testing the changes in the induced electromotive force voltage generated by the conductor cutting the magnetic lines of force. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 It is a structural schematic diagram of the detection device provided by the present invention; Figure 2 It is a theoretical model for ground fissure detection provided by the present invention; Figure 3 This is an improved theoretical model for ground fissure detection provided by the present invention. DETAILED DESCRIPTION

[0017] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0018] The earth's magnetic field is evenly distributed in uniform strata. The strata have different magnetic permeabilities. When other materials are distributed in the strata, the difference in magnetic permeability will cause the magnetic lines of force to overflow or converge, thereby changing their trajectories. Cutting the magnetic lines of force with a conductor will produce the characteristics of induced electromotive force. The conductor or coil moving at the position where the magnetic lines of force overflow will produce an induced electromotive force. By testing the abnormality of the induced electromotive force, the position of the abnormal strata under the surface can be determined. Based on this principle, the position and spatial distribution of ground cracks and cavities can be detected. Since the detection of geomagnetic anomalies is subject to many interference factors and the magnetic field distribution has vector characteristics, it is extremely difficult to measure magnetic anomalies using a Gauss meter. The signal is disturbed by the atmospheric magnetic field and has poor stability. The induced electromotive force test generated by cutting magnetic lines of force is also difficult due to weak current. However, conductors cutting magnetic lines of force will produce positive and negative charge distribution at both ends of the conductor. The magnetic anomaly signal can be captured by using the principle of attraction between positive and negative charges. In order to enhance the intensity of magnetic anomalies, the electromagnetic resonance frequency of the air is used to emit excitation electromagnetic waves under the characteristic conditions of the stable distribution of the earth's magnetic field to enhance the strength of the abnormal magnetic lines of force. The abnormal points can be detected mechanically to avoid electric field interference as much as possible.

[0019] The high magnetic permeability of the brass conductor and the capacitance characteristics of the human body are used to form a magnetic field induction conductor. The magnetic lines of force are cut to generate positive and negative charges at both ends of the copper wire, causing the copper wires to attract each other, and this method is used for detection.

[0020] This detection uses a brass mechanical detection rod to detect geomagnetic anomalies on the site to minimize the interference of electromagnetic equipment. After the magnetic anomaly is found, a low-energy, low-frequency, full-band electromagnetic wave transmitter is used to emit electromagnetic waves of air resonance frequency. The electromagnetic waves will be reflected outward at the bottom of the ground fissure. The electromagnetic waves diffuse to the ground at a 45° reflection diffusion angle. The magnetic lines of force overflow as a whole within the conical diffusion range, and anomalies will appear at the edge. The conductor moves here to cut the magnetic lines of force and generate induced voltage. The depth and inclination of the ground fissure at this point can be calculated using two abnormal points perpendicular to the direction of the ground fissure and the abnormal point on the ground of the ground fissure (which can be hidden).

[0021] Reference Figure 1 and Figure 2 , a ground fissure detection method comprises the following steps: The detection device is moved along the ground at a uniform speed to obtain the deflection state of the two transverse conductors, and the specific position of the object to be detected is determined according to the deflection state of the two transverse conductors; The detection device comprises: the detection device comprises: a transverse conductor 3, one end of the transverse conductor 3 is fixed on a screw cap 4, a conductor handle 1 is arranged perpendicular to the transverse conductor 3, and the upper part of the conductor handle 1 is rotatably connected to the screw cap 4; A capacitor box 2 is arranged on the transverse conductor 3, a capacitor is arranged in the capacitor box 2, and the input end and the output end of the capacitor are respectively connected to the conductor handle and the transverse conductor through wires to enhance the sensitivity of detection.

[0022] Furthermore, when performing detection, the left hand and the right hand of the human body respectively hold a detection device, so that the two transverse conductors in the detection device are in a parallel state, and the left hand and the right hand of the human body respectively hold a detection device to form an electromagnetic induction conductor; Mark the initial detection position, then move at a constant speed on the ground along the initial detection position, and record the first position of the deflection when the two detection devices deflect; A plurality of different positions are selected at the first position based on the first position, and a detection device is respectively held by the left hand and the right hand of the human body to form an electromagnetic induction conductor to perform detection along the selected plurality of different positions to delineate the scope of the ground fissure.

[0023] Furthermore, when performing detection, the device moves at a constant speed on the ground along the initial detection position, records the first position of the deflection when the two detection devices deflect, continues to move at a constant speed until the deflection of the two detection devices disappears, records any second position when the deflection disappears, and then continues to move at a constant speed until the two detection devices deflect again; records the third position; uses the line between the first position, the second position and the third position as the approximate diameter of the detected ground fissure, and uses the center of the line as a reference to frame a detection circle with the distance of the line as the radius, and then selects several detection points on the detection circle, uses the left and right hands of the human body to hold a detection device respectively to form an electromagnetic induction conductor, and performs detection along several different detection points to delineate the range of the ground fissure.

[0024] Furthermore, the wire arranged on the conductor handle is connected in series with the body capacitor by touching the wire by human hand, thereby increasing the strength of the transverse conductor in cutting the magnetic flux lines.

[0025] Furthermore, when the detection device is moved at a uniform speed perpendicular to the direction of the object to be detected, when the edge of the ground fissure to be detected is detected, the transverse conductors in the two detection devices held by the left hand and the right hand attract each other to form a pendulum.

[0026] Furthermore, when the transverse conductors in the two detection devices held by the left and right hands attract each other to form a pendulum, the position of the person and the angle of the pendulum are recorded, and the specific position of the edge of the ground fissure is obtained by recording the position of the person's movement and the angle of the pendulum.

[0027] Furthermore, when a person holds the detection device, the left hand and the right hand of the human body respectively hold a detection device to form an electromagnetic induction conductor. At the same time, the human body is used as a body capacitor, and the wire set on the conductor handle through the human hand touch pattern makes the capacitor and the human body as a body capacitor connected in series, thereby increasing the strength of the transverse conductor in cutting the magnetic flux lines.

[0028] Furthermore, when detecting ground fissures, the horizontal section formed by the ground fissures is used as the detection interface.

[0029] Furthermore, by constructing a theoretical model and an improved model for ground fissure detection, the depth and slope of the ground fissure can be obtained.

[0030] This application uses the stability of the natural geomagnetic field. Due to the difference in magnetic permeability of various materials, magnetic resistance will be generated, resulting in magnetic overflow or convergence on the surface. The presence and distribution of ground fissures are determined by detecting geomagnetic anomalies. This anomaly is discovered by testing the changes in the induced electromotive force voltage generated by the conductor cutting the magnetic lines of force.

[0031] The theoretical basis for the above method to be used in the detection of ground fissures is: treat rock and soil as materials, so that rock and soil not only have mechanical characteristics but also electromagnetic characteristics. That is to say, when rock and soil are regarded as magnetic bodies, they have a certain magnetic permeability, and the buried objects in the soil have a different magnetic permeability from the soil. When the geomagnetic field encounters different objects, it will overflow and converge on the ground, that is, the uniform magnetic lines will overflow or converge downward, and the induction conductor will generate an induced electromotive force when it moves on the ground where the magnetic lines overflow. In this application, the difference in magnetic permeability between rock and soil and air is used. When the detection device is roughly vertical (or at a certain angle) to the ground for uniform walking, if there is no ground fissure, then the transverse conductors in the two detection devices held by the left and right hands will not attract each other and swing towards each other (that is, the magnetic lines of force do not change significantly), but once there is a ground fissure, when walking near the ground fissure, the transverse conductors in the two detection devices held by the left and right hands will attract each other and swing towards each other.

[0032] It should be noted that the present application uses a combination of geomagnetism and electromagnetic induction technology to measure the location of ground fissures. It only requires a person to walk back and forth on the ground with a detection device, and there is no need to drill holes to analyze geological data.

[0033] Reference Figure 2 , a theoretical model for ground fissure detection is given. Using the theoretical model for ground fissure detection, the depth of the ground fissure can be calculated, and the width can be calculated based on the angle of deflection caused by the transverse conductors in the two detection devices moving toward each other in the natural magnetic field.

[0034] Specifically, when the detection device is moved at a constant speed perpendicular to the object to be detected to obtain magnetic field changes, the initial point when the anomaly occurs and the range of the anomaly position are recorded. The range of the anomaly position is roughly the width of the ground fissure or cavity.

[0035] When sending low-frequency resonant electromagnetic waves, the specific depth can be calculated by recording the distance between the ground position of the received reflected signal and the initial abnormal point. Specifically, after obtaining the specific position of the object to be measured, the electromagnetic wave transmitter sends a low-frequency resonant electromagnetic wave with the same resonance frequency as the inherent electromagnetic wave of the object to be measured to the object to be measured, and the object to be measured is identified according to whether the reflected signal corresponding to the low-frequency resonant electromagnetic wave can be received; and the depth of the object to be measured is calculated according to the distance between the received reflected signal and the initial abnormal point.

[0036] in, Figure 2 In the figure, the distance between the initial abnormal point of the low-frequency resonant electromagnetic wave and the point where the electromagnetic wave is reflected on the ground is L. Since the diffusion angle of the low-frequency resonant electromagnetic wave when reflected by the object to be measured is 90°, the depth H can be directly obtained according to the algorithm of the side length of the isosceles right triangle.

[0037] In this embodiment, the inherent electromagnetic wave resonance frequency of the ground fissure is 650-750 Hz.

[0038] It should be noted that the theoretical model for ground fissure detection provided above is an ideal model, which is effective for vertically extending ground fissure detection. During detection, the bottom of the ground fissure is regarded as a reflection plane, and a low-frequency resonant electromagnetic wave of 650-750 Hz is sent at any position around the specific position of the ground fissure obtained on the ground. The transmission signal formed by the low-frequency resonant electromagnetic wave of 650-750 Hz passing through the reflection plane is 45° to the earth's axis.

[0039] However, ground fissures do not extend vertically, but basically extend downward at a certain slope. Therefore, based on the theoretical model of ground fissure detection provided above, the present application also proposes an improved theoretical model for ground fissure detection, wherein the improved theoretical model can be applied to the detection of ground fissures with different slopes.

[0040] Reference Figure 3 , Figure 3 The algorithm diagram of the improved theoretical model is given.

[0041] When the ground fissure is generally inclined at a certain slope, the specific position of the ground fissure obtained by the detection method of the present application does not actually correspond to the emission plane formed at the bottom of the ground fissure.

[0042] The initial abnormal point during ground detection of ground fissures is recorded, and the distance between the initial abnormal point and the receiving position of the electromagnetic wave reflection (reflection signal) received on one side of the initial abnormal point to the ground point is recorded as L1, and the distance between the electromagnetic wave reflection (reflection signal) received on the other side of the initial abnormal point to the ground point is recorded as L2. Regardless of whether the ground fissure has an inclination, the transmission signal formed by the reflection plane using a low-frequency resonant electromagnetic wave of 650-750Hz is 45° to the earth's axis, and the overall transmission angle is 90°. The distance between the center point and the reflection plane is set to H, and H=(L1+L2) / 2, and the distance between the initial abnormal point and the center point is S=(L1-L2) / 2; then the overall inclination of the ground fissure is tanα=H / S.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting ground fissures, characterized in that: The steps include: The detection device is moved along the ground at a uniform speed to obtain the deflection state of the two transverse conductors, and the specific position of the object to be detected is determined according to the deflection state of the two transverse conductors; The detection device comprises: a transverse conductor, one end of which is fixed on a screw cap, a conductor handle is arranged perpendicular to the transverse conductor, and the upper part of the conductor handle is rotatably connected to the screw cap; A capacitor box is arranged on the transverse conductor, a capacitor is arranged in the capacitor box, and an input end and an output end of the capacitor are respectively connected to the conductor handle and the transverse conductor through wires to enhance the detection sensitivity.

2. The method for detecting ground fissures according to claim 1, characterized in that: When performing detection, the left and right hands of the human body hold a detection device respectively, so that the two transverse conductors in the detection device are in a parallel state, and the left and right hands of the human body hold a detection device respectively to form an electromagnetic induction conductor; Mark the initial detection position, then move at a constant speed on the ground along the initial detection position, and record the first position of the deflection when the two detection devices deflect; A plurality of different positions are selected at the first position based on the first position, and a detection device is respectively held by the left hand and the right hand of the human body to form an electromagnetic induction conductor to perform detection along the selected plurality of different positions to delineate the scope of the ground fissure.

3. The method for detecting ground fissures according to claim 1, characterized in that: When performing detection, move at a constant speed on the ground along the initial detection position, record the first position of the deflection when the two detection devices deflect, continue to move at a constant speed until the deflection of the two detection devices disappears, record any second position when the deflection disappears, and then continue to move at a constant speed until the two detection devices deflect again; record the third position; use the line between the first position, the second position and the third position as the approximate diameter of the detected ground fissure, and use the center of the line as a reference to frame a detection circle with the distance of the line as the radius, and then select several detection points on the detection circle, use the left and right hands of the human body to hold a detection device respectively to form an electromagnetic induction conductor to detect along several different directions to circle the range of the ground fissure.

4. The method for detecting ground fissures according to claim 1, characterized in that: The wire arranged on the conductor handle is connected in series with the body capacitance by touching the conductor by human hand, thereby increasing the strength of the transverse conductor in cutting the magnetic flux lines.

5. The method for detecting ground fissures according to claim 1, characterized in that: When the detection device is moved at a constant speed perpendicular to the direction of the object to be detected, when the edge of the ground fissure to be detected is detected, the transverse conductors in the two detection devices held by the left hand and the right hand attract each other to form a pendulum.

6. The method for detecting ground fissures according to claim 1, characterized in that: When the transverse conductors in the two detection devices held by the left and right hands attract each other to form a pendulum, the position of the person and the angle of the pendulum are recorded. The specific position of the edge of the ground fissure is obtained by recording the position of the person and the angle of the pendulum.

7. The method for detecting ground fissures according to claim 4, characterized in that: When a person holds the detection device, the left and right hands of the human body respectively hold a detection device to form an electromagnetic induction conductor. At the same time, the human body is used as a body capacitor, and the wire set on the conductor handle through the human hand touch pattern makes the capacitor and the human body as the body capacitor connected in series, thereby increasing the strength of the transverse conductor in cutting the magnetic flux lines.

8. The method for detecting ground fissures according to claim 1, characterized in that: When detecting ground fissures, the horizontal section formed by the ground fissures is used as the detection interface.

9. The method for detecting ground fissures according to claim 1, characterized in that: The transverse conductor and the conductor handle are both made of copper.

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