A method for detecting ground fissures

Abstract

The present invention discloses a method for detecting ground fissures, which includes the following steps: moving a detection device uniformly along the ground to obtain the deflection states of two transverse conductors, and judging the specific position of an object to be measured according to the deflection states of the two transverse conductors. This application utilizes the stability of the natural geomagnetic field. Due to the differences in the magnetic permeabilities of various substances, magnetic resistance will be generated, resulting in magnetic overflow or convergence on the ground surface. The existence and distribution of ground fissures are determined by detecting geomagnetic anomalies. This anomaly is discovered by testing the change in the induced electromotive force voltage generated when a conductor cuts magnetic lines of force.

Description

Technical Field

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

[0002] Traditional detection of ground fissures mainly relies on drill sampling and judgment by means of stratigraphic correlation. Actually, the theory of faults is introduced into ground fissures. The existing geophysical exploration methods have relatively large errors and are not recognized by everyone. The latest method currently is to use ground penetrating radar. By receiving and analyzing the reflected electromagnetic wave signals, the abnormal response of the fissures on the radar image can be clearly presented, which is convenient for positioning and morphological analysis of the fissures. Based on the current technical level, the detection depth is limited.

[0003] There is no effective and accurate detection method for underground cavities, especially those with a depth of more than 5 meters. Summary of the Invention

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

[0005] The main technical solution is as follows:

[0006] A method for detecting ground fissures, comprising the following steps:

[0007] Moving a detection device uniformly along the ground to obtain the deflection states of two transverse conductors, and judging the specific position of the object to be detected according to the deflection states of the two transverse conductors;

[0008] Wherein, the detection device includes: a transverse conductor, one end of the transverse conductor 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 rotationally connected to the screw cap;

[0009] A capacitor box is arranged on the transverse conductor, a capacitor is arranged in the capacitor box, 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 detection sensitivity.

[0010] Further, when detecting, the left hand and the right hand of the human body are respectively used to 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 are respectively used to hold a detection device to form an electromagnetic induction conductor;

[0011] Mark the initial detection position, and then move uniformly along the initial detection position on the ground. When the two detection devices deflect, record the first position of the deflection;

[0012] Select a number of different positions based on the first position. Use the left and right hands of the human body to hold a detection device respectively to form an electromagnetic induction conductor and detect along the selected different positions to delineate the scope of the ground fissure.

[0013] Further, when detecting, move uniformly on the ground along the initial detection position. When the two detection devices deflect, record the first position of the deflection. Continue to move uniformly until the state of deflection of the two detection devices disappears, record any second position when it disappears, and then continue to move uniformly until the two detection devices deflect again; record the third position; use the connection line between the first position, the second position and the third position as the approximate diameter of the detected ground fissure, and frame a detection circle with the distance of the connection line as the radius with the center of the connection line as the reference. Then select a number of 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 and detect along the selected different detection points to delineate the scope of the ground fissure.

[0014] Further, by touching the wire arranged on the conductor handle by hand, the body capacitance is connected in series, so as to increase the intensity of the lateral conductor cutting the magnetic induction line.

[0015] Further, when the detection device is moved uniformly perpendicular to the direction of the object to be measured, when the edge position of the ground fissure to be detected is detected, the lateral conductors in the two detection devices held by the left and right hands attract each other to form a deflection.

[0016] Further, during the process that the lateral conductors in the two detection devices held by the left and right hands attract each other to form a deflection, record the position of the person when the deflection is formed and the deflection angle, and obtain the specific position of the ground fissure edge by recording the position of the person's movement and the deflection angle.

[0017] Further, when a person holds the detection device, use the left and right hands of the human body to hold a detection device respectively to form an electromagnetic induction conductor. At the same time, taking the human body as the body capacitance, by touching the wire arranged on the conductor handle by hand, the capacitance and the human body as the body capacitance are connected in series, so as to increase the intensity of the lateral conductor cutting the magnetic induction line.

[0018] Further, when detecting the ground fissure, take the horizontal section formed by the ground fissure as the detection interface.

[0019] Further, both the lateral conductor and the conductor handle are made of copper.

[0020] This application utilizes the stability of the natural geomagnetic field. Due to the differences in the magnetic permeability of various substances, magnetic resistance will be generated, resulting in magnetic overflow or convergence on the earth's surface. By detecting geomagnetic anomalies, the existence and distribution of ground fissures can be determined. This anomaly is discovered by testing the change in the induced electromotive force voltage generated when a conductor cuts the magnetic force lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 is a schematic structural diagram of the detection device provided by the present invention;

[0023] Figure 2 is a theoretical model for ground fissure detection provided by the present invention;

[0024] Figure 3 is an improved theoretical model for ground fissure detection provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will further describe the embodiments of the present invention in detail in conjunction with the drawings.

[0026] The earth's magnetic field is evenly distributed in a uniform stratum. Each stratum has its own different magnetic permeability. When there are other substances distributed in the stratum, due to the different magnetic permeabilities, it will cause the overflow or convergence change of the magnetic force lines, thus changing the trajectory. Utilizing the characteristic that a conductor cutting the magnetic force lines will generate an induced electromotive force, a moving conductor or coil at the position where the magnetic force lines overflow will generate an induced electromotive force. By testing the anomaly of the induced electromotive force, the position of the subsurface stratum anomaly can be determined. Based on this principle, the positions and spatial distributions of ground fissures and cavities can be detected. Since the detection of geomagnetic anomalies is affected by many interference factors and the magnetic field distribution has vector characteristics, it is extremely difficult to measure magnetic anomalies using a gaussmeter. The signal is unstable due to interference from the atmospheric magnetic field. And it is also difficult to test using the induced electromotive force generated by cutting the magnetic force lines because the current is weak. However, when a conductor cuts the magnetic force lines, positive and negative charges will be distributed at both ends of the conductor. Utilizing the principle of the attraction between positive and negative charges, the magnetic anomaly signal can be captured. To enhance the magnetic anomaly intensity, under the condition of utilizing the stable distribution characteristic of the earth's magnetic field, electromagnetic resonance frequency of air is used to emit and excite electromagnetic waves to enhance the intensity of the abnormal magnetic force lines. The abnormal points can be detected by mechanical means, and electric field interference can be avoided as much as possible.

[0027] Using the high magnetic permeability of the brass conductor and the capacitance characteristics of the human body to form a magnetic field induction conductor, cutting the magnetic field lines generates positive and negative charges at both ends of the copper wire, causing the copper wires to attract each other and conducting detection work in this way.

[0028] In this detection, a brass mechanical detection rod is used to detect the geomagnetic anomalies in the site, minimizing the interference of electromagnetic devices. After detecting the magnetic anomalies, a low-energy low-frequency full-band electromagnetic wave transmitter is used to emit electromagnetic waves at the air resonance frequency. The electromagnetic waves will reflect outward at the bottom of the ground fissure. The electromagnetic waves diffuse to the ground at a 45° reflection diffusion angle. The magnetic field lines overflow as a whole within the conical diffusion range, and anomalies will appear at the edges. When the conductor moves here to cut the magnetic field lines, an induced voltage will be generated. Using two anomaly points perpendicular to the trend of the ground fissure and the ground anomaly point (which can be hidden) of the ground fissure, the depth and dip angle of the ground fissure at this point can be calculated.

[0029] Refer to Figure 1 and Figure 2 , a detection method for ground fissures, comprising the following steps:

[0030] Moving the detection device uniformly along the ground to obtain the deflection states of two transverse conductors, and judging the specific position of the object to be measured according to the deflection states of the two transverse conductors;

[0031] Among them, the detection device includes: 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;

[0032] A capacitance box 2 is arranged on the transverse conductor 3. A capacitor is arranged in the capacitance box 2, and the input end and output end of the capacitor are respectively connected to the conductor handle and the transverse conductor through wires to enhance the detection sensitivity.

[0033] Furthermore, during detection, the left hand and right hand of the human body are respectively used to hold a detection device, so that the two transverse conductors in the detection device are in a parallel state, and the left hand and right hand of the human body are respectively used to hold a detection device to form an electromagnetic induction conductor;

[0034] Mark the initial detection position, and then move uniformly along the initial detection position on the ground. When the two detection devices deflect, record the first position of the deflection;

[0035] Taking the first position as a reference, select several different positions at the first position. Use the left hand and right hand of the human body to respectively hold a detection device to form an electromagnetic induction conductor to detect along the selected several different positions to delineate the range of the ground fissure.

[0036] Further, during detection, move uniformly along the initial detection position on the ground. When the two detection devices deflect, record the first position of the deflection. Continue to move uniformly until the state of deflection of the two detection devices disappears, and record any second position when it disappears. Then continue to move uniformly until the two detection devices deflect again; record the third position. Use the connection line between the first position, the second position, and the third position as the approximate diameter of the detected ground fissure, and frame a detection circle with the center of this connection line as the benchmark and the distance of the connection line as the radius. Then select several detection points on the detection circle, and 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 detection points to delineate the scope of the ground fissure.

[0037] Further, by touching the wire arranged on the conductor handle by hand, the body capacitance is connected in series, thereby increasing the intensity of the lateral conductor cutting the magnetic induction line.

[0038] Further, when the detection device is moved uniformly perpendicular to the direction of the object to be measured, when the edge position of the ground fissure to be detected is detected, the lateral conductors in the two detection devices held by the left and right hands attract each other to form a deflection.

[0039] Further, during the process that the lateral conductors in the two detection devices held by the left and right hands attract each other to form a deflection, record the position of the person when the deflection is formed and the angle of the deflection, and obtain the specific position of the edge of the ground fissure by recording the position where the person moves and the angle of the deflection.

[0040] Further, when a person holds the detection device, use the left and right hands of the human body to hold a detection device respectively to form an electromagnetic induction conductor. At the same time, taking the human body as the body capacitance, by touching the wire arranged on the conductor handle by hand, the capacitance and the body capacitance with the human body are connected in series, thereby increasing the intensity of the lateral conductor cutting the magnetic induction line.

[0041] Further, when detecting the ground fissure, use the horizontal section formed by the ground fissure as the detection interface.

[0042] Further, by constructing a theoretical model and an improved model for ground fissure detection, the depth and slope of the ground fissure are obtained.

[0043] This application utilizes the stability of the natural geomagnetic field. Due to the difference in magnetic permeability of various substances, magnetic resistance will be generated, resulting in magnetic overflow or convergence on the ground surface. The existence and distribution of ground fissures are determined by detecting geomagnetic anomalies. This anomaly is discovered by testing the change in the induced electromotive force voltage generated when the conductor cuts the magnetic induction line.

[0044] The theoretical basis for applying the above method to the detection of ground fissures is as follows: Regarding rock and soil as materials, rock and soil not only have mechanical characteristics but also electromagnetic characteristics. That is to say, when considering rock and soil as magnetic bodies, they have a certain magnetic permeability. The buried objects in the soil have different magnetic permeabilities from the soil. When the geomagnetic field encounters different objects, overflows and convergences will occur on the ground, that is, uniform magnetic field lines will overflow or converge downward. When the induction conductor moves on the ground where the magnetic field lines overflow, an induced electromotive force will be generated. In this application, by using the difference in magnetic permeability between rock and soil and air, when the detection device walks uniformly approximately perpendicular (or at a certain angle) to the ground, if there are no ground fissures, then the lateral conductors in the two detection devices held in the left and right hands will not attract and swing towards each other (that is, the magnetic field lines do not change significantly). However, once there are ground fissures, when approaching the ground fissures, the lateral conductors in the two detection devices held in the left and right hands will attract and swing towards each other.

[0045] It should be noted that for the measurement of the location of ground fissures using the technology method of combining geomagnetism and electromagnetic induction in this application, it only requires a person to hold the detection device and walk back and forth on the ground, without the need to drill holes to analyze geological data.

[0046] Refer to 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 obtained. As for the width, it can be calculated based on the angle of the lateral conductors in the two detection devices moving towards each other and swinging in the natural magnetic field.

[0047] Specifically, when the detection device moves uniformly perpendicular to the object to be measured to obtain magnetic field changes, record the initial point when anomalies occur and the range of the anomaly position. The range of the anomaly position is approximately the width of the ground fissure or cavity.

[0048] When sending low-frequency resonance electromagnetic waves, the specific depth can be calculated by recording the distance between the ground position of the received reflected signal and the initial anomaly point. Specifically, after obtaining the specific position of the object to be measured, send low-frequency resonance electromagnetic waves with the same resonance frequency as the inherent electromagnetic wave of the object to be measured through the electromagnetic wave transmitter, and identify the object to be measured according to whether the reflected signal corresponding to the low-frequency resonance electromagnetic wave can be received; and calculate the depth of the object to be measured according to the distance between the received reflected signal and the initial anomaly point.

[0049] Among them, Figure 2 In, the distance between the initial anomaly point of the low-frequency resonance electromagnetic wave and the point where the electromagnetic wave is reflected to the ground is L. Since the diffusion angle of the low-frequency resonance 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 an isosceles right triangle.

[0050] In this embodiment, the inherent electromagnetic wave resonance frequency of the ground fissure is 650 - 750 Hz.

[0051] It should be noted that the theoretical model for ground fissure detection provided above is an ideal model, and this ideal model is effective for detecting vertically extending ground fissures. During detection, the bottom of the ground fissure is regarded as the reflection plane. When a low-frequency resonance electromagnetic wave of 650 - 750 Hz is sent at any position around the specific position of the ground fissure obtained on the ground, the emission signal formed by the reflection of this 650 - 750 Hz low-frequency resonance electromagnetic wave through the reflection plane makes an angle of 45° with the earth's axis.

[0052] However, ground fissures do not extend vertically. Basically, they all extend downward at a certain slope. Therefore, based on the theoretical model for ground fissure detection provided above, this application also proposes an improved theoretical model for ground fissure detection, where this improved theoretical model can be applied to the detection of ground fissures with different slopes.

[0053] Refer to Figure 3 , Figure 3 which gives a schematic diagram of the algorithm of the improved theoretical model.

[0054] When the ground fissure is inclined at a certain slope overall, actually the specific position of the ground fissure obtained by using the detection method of this application does not correspond to the emission plane formed by the bottom of the ground fissure.

[0055] Record the initial abnormal point when detecting the ground fissure on the ground. Denote the distance between the initial abnormal point and the receiving position on the ground where the electromagnetic wave reflection (reflection signal) received on one side of the initial abnormal point reaches as L1, and the distance between the initial abnormal point and the receiving position on the ground where the electromagnetic wave reflection (reflection signal) received on the other side of the initial abnormal point reaches as L2. Whether the ground fissure has an inclination or not, when using a low-frequency resonance electromagnetic wave of 650 - 750 Hz, the emission signal formed by the reflection through the reflection plane makes an angle of 45° with the earth's axis, and the overall emission angle is 90°. Let the distance between the center point and the reflection plane be H, and H = (L1 + L2) / 2, and the distance S between the initial abnormal point and the center point is S = (L1 - L2) / 2; then the overall slope of the ground fissure is tanα = H / S.

[0056] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for detecting ground fissures, characterized in that, It includes the following steps: Move the detection device uniformly along the ground to obtain the deflection states of two transverse conductors, and judge the specific position of the to-be-detected ground fissure according to the deflection states of the two transverse conductors; specifically: when detecting, hold a detection device with the left hand and the right hand of the human body respectively, so that the two transverse conductors in the detection device are in a parallel state, and hold a detection device with the left hand and the right hand of the human body respectively to form an electromagnetic induction conductor; Mark the initial detection position, and then move uniformly along the initial detection position on the ground. When the two detection devices deflect, record the first position of the deflection; Among them, the detection device includes: a transverse conductor, one end of the transverse conductor is fixed on a screw cap, and a conductor handle perpendicular to the transverse conductor is provided. The upper part of the conductor handle is rotationally connected to the screw cap; A capacitor box is arranged on the transverse conductor, a capacitor is arranged in the capacitor box, 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 detection sensitivity; Continue to move uniformly until the deflection states of the two detection devices disappear, record the second position, and then continue to move uniformly until the two detection devices deflect again, and record the third position; use the connection line between the first position, the second position and the third position as the detected ground fissure diameter, and frame a detection circle with the distance of the connection line as the radius with the center of the connection line as the reference. Then select several detection points on the detection circle, and hold a detection device with the left hand and the right hand of the human body respectively to form an electromagnetic induction conductor to detect along the selected several detection points to delineate the range of the ground fissure.

2. The detection method of ground fissures according to claim 1, characterized in that, Make the body capacitance achieve series connection by touching the wire arranged on the conductor handle by hand, so as to increase the intensity of the transverse conductor cutting the magnetic induction line.

3. The detection method of ground fissures according to claim 1, characterized in that, When the detection device is moved uniformly perpendicular to the direction of the to-be-detected ground fissure, when the edge position of the to-be-detected ground fissure 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 deflection.

4. The detection method of ground fissures according to claim 3, characterized in that, During the process that the transverse conductors in the two detection devices held by the left hand and the right hand attract each other to form a deflection, record the position of the person when the deflection is formed and the deflection angle, and obtain the specific position of the ground fissure edge by recording the position of the person moving and the deflection angle.

5. The detection method of ground fissures according to claim 3, characterized in that, When holding the detection device by hand, hold a detection device with the left hand and the right hand of the human body respectively to form an electromagnetic induction conductor. At the same time, use the human body as the body capacitance, and make the capacitance and the body capacitance achieve series connection by touching the wire arranged on the conductor handle by hand, so as to increase the intensity of the transverse conductor cutting the magnetic induction line.

6. The detection method of ground fissures according to claim 1, characterized in that, When detecting the ground fissure, use the horizontal section formed by the ground fissure as the detection interface.

7. The detection method of ground fissures according to claim 1, characterized in that, Both the transverse conductor and the conductor handle are made of copper material.

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